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Spennemann, Dirk H. R., Melissa Pike, and Maggie J. Watson. "Bird impacts on heritage buildings." Journal of Cultural Heritage Management and Sustainable Development 8, no. 1 (February 6, 2018): 62–75. http://dx.doi.org/10.1108/jchmsd-07-2016-0042.
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Purpose There is much anecdotal evidence that birds and their droppings are a major problem for the heritage profession. The purpose of this paper is to examine how serious heritage practitioners consider the bird impact to be. Design/methodology/approach An online survey was conducted of 59 Australian heritage professionals of between one and >20 year’s experience in the field. Findings Bird impacts were not considered of major concern to buildings. The longer experience a practitioner had, the less likely the impacts were considered an issue. Feral pigeons were deemed the most problematic, followed by cockatoos, starlings, swallows, seagulls, mynas, sparrows, cormorants, ibis, ducks and birds of prey. The professionals ranked common deterrent methods. The highest-ranking deterrents were bird netting and bird spikes, but they were only considered moderately effective. The costs of installation and maintenance, as well the ease of installation, were all deemed significantly less important than the physical impact, the aesthetic sympathy and the effectiveness of a deterrent method. Practical implications This study indicates that the impact of birds on buildings in Australia may be of less concern than previously thought, and may be driven by other factors (i.e. aesthetics, commercial companies) rather than actual effects. Originality/value This is first study of its kind that surveyed the experiences of a wide range of heritage practitioners.
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Manihuruk, Santa Ramayana, Keliopas Krey, and Ursula Paula Maker. "TAHAPAN PERKEMBANGBIAKAN KUPU-KUPU SAYAP BURUNG (ORNITHOPTERA GOLIATH) DI CAGAR ALAM PEGUNUNGAN ARFAK." VOGELKOP: Jurnal Biologi 2, no. 1 (September 8, 2020): 28–35. http://dx.doi.org/10.30862/vogelkopjbio.v2i1.53.
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ABSTRACT Butterflies are one of the natural resources and are part of the biodiversity that must be preserved. Efforts to patronize bird wing butterflies (Ornithoptera goliath) are an alternative in the preservation of bird wing butterflies which are presently endangered. Efforts to preserve bird wing butterflies (Ornithoptera goliath) have not been widely carried out and there is no data on the breeding stage because information about butterflies is not widely known. This study aims to analyze the stages of development or life cycle (from caterpillars to cocoons) bird wing butterflies (Ornithoptera goliath) in the buffer zone of the Arfak Mountains Nature Reserve. The method used is descriptive method with direct observation techniques in the field. The characteristics of the morphological structure of the young caterpillar recorded were small and short body shapes, the initial length is 0.55 cm and diameter is 0.15 cm, the whole body was blackish brown, there was a whitish yellow stripe on the back. There are soft spikes in all parts of the body and a pair of orange antennas in the head, head and abdomen in black. The morphological structure characteristics of adult caterpillars are elongated oval body 4,15 cm long and 1.25 cm in diameter. The head and abdomen are black, the whole body is black, there are soft black spikes all over the body, on the dorsal mid-body there is a white line, a pair of orange antennas on the head. Bird wing butterflies (Ornithoptera goliath) have a life cycle to cocoon for 48 to 51 days. ABSTRAK Kupu-kupu merupakan salah satu sumberdaya alam dan merupakan bagian dari keanekaragaman hayati yang harus dijaga kelestariannya. Usaha penagkaran terhadap kupu-kupu sayap burung (Ornithoptera goliath) merupakan alternatif dalam pelestarian kupu-kupu sayap burung yang saat ini mulai terancam kelestariannya. Usaha pelestarian kupu-kupu sayap burung (Ornithoptera goliath) belum banyak dilakukan serta belum ada data informasi tahap perkembangbiakannya disebabkan informasi mengenai kupu-kupu belum banyak diketahui. Penelitian ini bertujuan untuk menganalisis tahapan perkembangan atau siklus hidup (dari ulat hingga kepompong) kupu-kupu sayap burung (Ornithoptera goliath) di daerah penyangga Cagar Alam Pegunungan Arfak. Metode yang digunakan adalah metode deskriptif dengan tehnik pengamatan langsung di lapangan. Karakteristik struktur morfologi ulat muda yang direkam adalah bentuk tubuh kecil dan pendek, dengan ukuran ratarata 0,55 cm dan diameter 0,15 cm, seluruh tubuh berwarna cokelat kehitaman, terdapat corak bergaris kuning keputihan pada bagian punggung. Terdapat duri-duri lunak di seluruh bagian tubuh dan sepasang antena berwarna orange di bagian kepala, Kepala dan abdomen berwarna hitam. Karakteristik struktur morfologi ulat dewasa adalah tubuh lonjong memanjang, panjang 4,15 cm dan diameter 1,25 cm. Kepala dan abdomen berwarna hitam, seluruh tubuh berwarna hitam, terdapat duri-duri lunak hitam di seluruh tubuh, pada bagian dorsal mid-body terdapat garis berwarna putih, sepasang antenna berwarna orange dibagian kepala. Kupu-kupu sayap burung (Ornithoptera goliath) mempunyai siklus hidup hingga kepompong selama 48 hingga 51 hari.
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Köppl, Christine. "Frequency Tuning and Spontaneous Activity in the Auditory Nerve and Cochlear Nucleus Magnocellularis of the Barn Owl Tyto alba." Journal of Neurophysiology 77, no. 1 (January 1, 1997): 364–77. http://dx.doi.org/10.1152/jn.1997.77.1.364.
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Köppl, Christine. Frequency tuning and spontaneous activity in the auditory nerve and cochlear nucleus magnocellularis of the barn owl Tyto alba. J. Neurophysiol. 77: 364–377, 1997. Single-unit recordings were obtained from the brain stem of the barn owl at the level of entrance of the auditory nerve. Auditory nerve and nucleus magnocellularis units were distinguished by physiological criteria, with the use of the response latency to clicks, the spontaneous discharge rate, and the pattern of characteristic frequencies encountered along an electrode track. The response latency to click stimulation decreased in a logarithmic fashion with increasing characteristic frequency for both auditory nerve and nucleus magnocellularis units. The average difference between these populations was 0.4–0.55 ms. The most sensitive thresholds were ∼0 dB SPL and varied little between 0.5 and 9 kHz. Frequency-threshold curves showed the simple V shape that is typical for birds, with no indication of a low-frequency tail. Frequency selectivity increased in a gradual, power-law fashion with increasing characteristic frequency. There was no reflection of the unusual and greatly expanded mapping of higher frequencies on the basilar papilla of the owl. This observation is contrary to the equal-distance hypothesis that relates frequency selectivity to the spatial respresentation in the cochlea. On the basis of spontaneous rates and/or sensitivity there was no evidence for distinct subpopulations of auditory nerve fibers, such as the well-known type I afferent response classes in mammals. On the whole, barn owl auditory nerve physiology conformed entirely to the typical patterns seen in other bird species. The only exception was a remarkably small spread of thresholds at any one frequency, this being only 10–15 dB in individual owls. Average spontaneous rate was 72.2 spikes/s in the auditory nerve and 219.4 spikes/s for nucleus magnocellularis. This large difference, together with the known properties of endbulb-of-Held synapses, suggests a convergence of ∼2–4 auditory nerve fibers onto one nucleus magnocellularis neuron. Some auditory nerve fibers as well as nucleus magnocellularis units showed a quasiperiodic spontaneous discharge with preferred intervals in the time-interval histogram. This phenomenon was observed at frequencies as high as 4.7 kHz.
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Machač, Ondřej, and Ivan Hadrián Tuf. "Ornithologists’ Help to Spiders: Factors Influencing Spiders Overwintering in Bird Nesting Boxes." Insects 12, no. 5 (May 18, 2021): 465. http://dx.doi.org/10.3390/insects12050465.
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Spiders are common inhabitants of tree hollows, as well as bird nesting boxes, especially in autumn and winter. Some species of spiders use bird nesting boxes for overwintering. We investigated spider assemblages in nesting boxes and how temperature influences the abundance of overwintering spiders in nesting boxes in lowland forest in the Czech Republic. The study was conducted in the European winters of 2015–2017. In total, 3511 spider specimens belonging to 16 identified species were collected from nesting boxes over three years in late autumn and winter. Almost all species were arboreal specialists. The dominant species were Clubiona pallidula, Anyphaena accentuata, Platnickina tincta, and Steatoda bipunctata. Although the tree species had no effect on the abundance of overwintering spiders, the presence of nest material affected the abundance of spiders in the nesting boxes (preferred by C. pallidula and P. tincta). In general, spiders resettled nesting boxes during winter only sporadically, however A. accentuata reoccupied boxes continuously, and its activity was positively correlated with the outside temperature. Nesting boxes support insect-eaters all year around—birds during spring and summer and spiders during autumn and winter.
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Barbaro, Luc, Eric Allan, Evy Ampoorter, Bastien Castagneyrol, Yohan Charbonnier, Hans De Wandeler, Christian Kerbiriou, et al. "Biotic predictors complement models of bat and bird responses to climate and tree diversity in European forests." Proceedings of the Royal Society B: Biological Sciences 286, no. 1894 (January 9, 2019): 20182193. http://dx.doi.org/10.1098/rspb.2018.2193.
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Bats and birds are key providers of ecosystem services in forests. How climate and habitat jointly shape their communities is well studied, but whether biotic predictors from other trophic levels may improve bird and bat diversity models is less known, especially across large bioclimatic gradients. Here, we achieved multi-taxa surveys in 209 mature forests replicated in six European countries from Spain to Finland, to investigate the importance of biotic predictors (i.e. the abundance or activity of defoliating insects, spiders, earthworms and wild ungulates) for bat and bird taxonomic and functional diversity. We found that nine out of 12 bird and bat diversity metrics were best explained when biotic factors were added to models including climate and habitat variables, with a mean gain in explained variance of 38% for birds and 15% for bats. Tree functional diversity was the most important habitat predictor for birds, while bats responded more to understorey structure. The best biotic predictors for birds were spider abundance and defoliating insect activity, while only bat functional evenness responded positively to insect herbivory. Accounting for potential biotic interactions between bats, birds and other taxa of lower trophic levels will help to understand how environmental changes along large biogeographical gradients affect higher-level predator diversity in forest ecosystems.
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Goldberg, Jesse H., Michael A. Farries, and Michale S. Fee. "Integration of cortical and pallidal inputs in the basal ganglia-recipient thalamus of singing birds." Journal of Neurophysiology 108, no. 5 (September 1, 2012): 1403–29. http://dx.doi.org/10.1152/jn.00056.2012.
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The basal ganglia-recipient thalamus receives inhibitory inputs from the pallidum and excitatory inputs from cortex, but it is unclear how these inputs interact during behavior. We recorded simultaneously from thalamic neurons and their putative synaptically connected pallidal inputs in singing zebra finches. We find, first, that each pallidal spike produces an extremely brief (∼5 ms) pulse of inhibition that completely suppresses thalamic spiking. As a result, thalamic spikes are entrained to pallidal spikes with submillisecond precision. Second, we find that the number of thalamic spikes that discharge within a single pallidal interspike interval (ISI) depends linearly on the duration of that interval but does not depend on pallidal activity prior to the interval. In a detailed biophysical model, our results were not easily explained by the postinhibitory “rebound” mechanism previously observed in anesthetized birds and in brain slices, nor could most of our data be characterized as “gating” of excitatory transmission by inhibitory pallidal input. Instead, we propose a novel “entrainment” mechanism of pallidothalamic transmission that highlights the importance of an excitatory conductance that drives spiking, interacting with brief pulses of pallidal inhibition. Building on our recent finding that cortical inputs can drive syllable-locked rate modulations in thalamic neurons during singing, we report here that excitatory inputs affect thalamic spiking in two ways: by shortening the latency of a thalamic spike after a pallidal spike and by increasing thalamic firing rates within individual pallidal ISIs. We present a unifying biophysical model that can reproduce all known modes of pallidothalamic transmission—rebound, gating, and entrainment—depending on the amount of excitation the thalamic neuron receives.
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Tsai, Jean C., Bruce D. Zelus, Kathryn V. Holmes, and Susan R. Weiss. "The N-Terminal Domain of the Murine Coronavirus Spike Glycoprotein Determines the CEACAM1 Receptor Specificity of the Virus Strain." Journal of Virology 77, no. 2 (January 15, 2003): 841–50. http://dx.doi.org/10.1128/jvi.77.2.841-850.2003.
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ABSTRACT Using isogenic recombinant murine coronaviruses expressing wild-type murine hepatitis virus strain 4 (MHV-4) or MHV-A59 spike glycoproteins or chimeric MHV-4/MHV-A59 spike glycoproteins, we have demonstrated the biological functionality of the N-terminus of the spike, encompassing the receptor binding domain (RBD). We have used two assays, one an in vitro liposome binding assay and the other a tissue culture replication assay. The liposome binding assay shows that interaction of the receptor with spikes on virions at 37°C causes a conformational change that makes the virions hydrophobic so that they bind to liposomes (B. D. Zelus, J. H. Schickli, D. M. Blau, S. R. Weiss, and K. V. Holmes, J. Virol. 77: 830-840, 2003). Recombinant viruses with spikes containing the RBD of either MHV-A59 or MHV-4 readily associated with liposomes at 37°C in the presence of soluble mCEACAM1a, except for S4R, which expresses the entire wild-type MHV-4 spike and associated only inefficiently with liposomes following incubation with soluble mCEACAM1a. In contrast, soluble mCEACAM1b allowed viruses with the MHV-A59 RBD to associate with liposomes more efficiently than did viruses with the MHV-4 RBD. In the second assay, which requires virus entry and replication, all recombinant viruses replicated efficiently in BHK cells expressing mCEACAM1a. In BHK cells expressing mCEACAM1b, only viruses expressing chimeric spikes with the MHV-A59 RBD could replicate, while replication of viruses expressing chimeric spikes with the MHV-4 RBD was undetectable. Despite having the MHV-4 RBD, S4R replicated in BHK cells expressing mCEACAM1b; this is most probably due to spread via CEACAM1 receptor-independent cell-to-cell fusion, an activity displayed only by S4R among the recombinant viruses studied here. These data suggest that the RBD domain and the rest of the spike must coevolve to optimize function in viral entry and spread.
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GAN, Wenjin, Fengxiang Liu, Zengtao Zhang, and Daiqin LI. "Predator perception of detritus and eggsac decorations spun by orb-web spiders Cyclosa octotuberculata: Do they function to camouflage the spiders?" Current Zoology 56, no. 3 (June 1, 2010): 379–87. http://dx.doi.org/10.1093/czoolo/56.3.379.
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Abstract Camouflage is one of the most widespread and powerful strategies that animals use to make detection/recognition more difficult. Many orb-web spiders of the genus Cyclosa add prey remains, plant debris, moults, and/or eggsacs to their webs called web decorations. Web decorations resembling spider body colour pattern have been considered to camouflage the spider from predators. While this camouflage is obvious from a human's perspective, it has rarely been investigated from a predator's perspective. In this study, we tested the visibility of web decorations by calculating chromatic and achromatic contrasts of detritus and eggsac decorations built by Cyclosa octotuberculata, against four different backgrounds viewed by both bird (e.g., blue tits) and hymenopteran (e.g. wasps) predators. We showed that both juvenile and adult spiders on webs with detritus or egg-sac decorations were undetectable by both hymenopteran and bird predators over short and long distances. Our results thus suggest that decorating webs with detritus or eggsacs by C. octotuberculata may camouflage the spiders from both hymenopteran and bird predators in their common habitats.
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Jones, Timothy A., and Sherri M. Jones. "Spontaneous Activity in the Statoacoustic Ganglion of the Chicken Embryo." Journal of Neurophysiology 83, no. 3 (March 1, 2000): 1452–68. http://dx.doi.org/10.1152/jn.2000.83.3.1452.
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Statoacoustic ganglion cells in the mature bird include neurons that are responsive to sound (auditory) and those that are not (nonauditory). Those that are nonauditory have been shown to innervate an otolith organ, the macula lagena, whereas auditory neurons innervate the basilar papilla. In the present study, single-unit recordings of statoacoustic ganglion cells were made in embryonic (E19, mean = 19.2 days of incubation) and hatchling (P6–P14, mean = 8.6 days posthatch) chickens. Spontaneous activity from the two age groups was compared with developmental changes. Activity was evaluated for 47 auditory, 11 nonauditory, and 6 undefined eighth nerve neurons in embryos and 29 auditory, 26 nonauditory, and 1 undefined neurons in hatchlings. For auditory neurons, spontaneous activity displayed an irregular pattern [discharge interval coefficient of variation (CV) was >0.5, mean CV for embryos was 1.46 ± 0.58 and for hatchlings was 1.02 ± 0.25; means ± SD]. Embryonic discharge rates ranged from 0.05 to 97.6 spikes per second (sp/s) for all neurons (mean 18.6 ± 16.9 sp/s). Hatchling spontaneous rates ranged from 1.2 to 185.2 sp/s (mean 66.5 ± 39.6 sp/s). Discharge rates were significantly higher for hatchlings ( P < 0.001). Many embryonic auditory neurons displayed long silent periods between irregular bursts of neural activity, a feature not seen posthatch. All regular bursting discharge patterns were correlated with heart rate in both embryos and hatchlings. Preferred intervals were visible in the time interval histograms (TIHs) of only one embryonic neuron in contrast to 55% of the neurons in posthatch animals. Generally, the embryonic auditory TIH displayed a modified quasi-Poisson distribution. Nonauditory units generally displayed regular (CV <0.5) or irregular (CV >0.5) activity and Gaussian and modified-Gaussian TIHs. Long silent periods or bursting patterns were not a characteristic of embryonic nonauditory neurons. CV varied systematically as a function of discharge rate in nonauditory but not auditory primary afferents. Minimum spike intervals (dead time) and interval modes for auditory neurons were longer in embryos (dead time: embryos 2.88 ± 6.85 ms; hatchlings 1.50 ± 1.76 ms; modal intervals: embryo 10.09 ± 22.50 ms, hatchling 3.54 ± 3.29 ms). The results show that significant developmental changes occur in spontaneous activity between E19 and posthatch. It is likely that both presynaptic and postsynaptic changes in the neuroepithelium contribute to maturational refinements during this period of development.
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Atlegrim, Ola, and Kjell Sjöberg. "Effects of clear-cutting and selective felling in Swedish Boreal coniferous forest: response of invertebrate taxa eaten by birds." Entomologica Fennica 6, no. 2-3 (September 1, 1995): 79–90. http://dx.doi.org/10.33338/ef.83843.
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Our aim was to analyse the short-term effects (0-4 years) of selective felling and clear-cutting on the food resources of insectivorous birds. Literature data on bird diets showed that herbivorous larvae (Lepidoptera and Hymenoptera: Symphyta) and spiders (Araneae) were used by 81 and 50%, respectively, of 16 bird species breeding in the Swedish boreal coniferous forest. A field study comparing selective fellings, clear-cuttings and uncut controls showed considerable effects of clear-cutting on both terricolous and field layer invertebrates. Clear-cuttings had significantly lower abundance and biomass, and a different composition of herbivorous larvae and spiders, as well as a lower total biomass of invertebrates in the field layer than controls. Drastic changes of abiotic factors (like increased temperature range) following clear-cutting may directly affect the occurrence of invertebrates. However, indirect effects (like increased sun exposure, affecting food plant quality for herbivorous larvae) are probably also responsible. Selective fellings did not differ from controls in the occurrence of herbivorous larvae and spiders. Therefore, over the four-year term of our study, selective felling seems to provide birds with conditions similar to uncut forest for invertebrates used by birds.
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Srivastava, U. C., Durgesh Singh, Prashant Kumar, and Sippy Singh. "Neuronal diversity and their spine density in the hippocampal complex of the House Crow (Corvus splendens), a food-storing bird." Canadian Journal of Zoology 94, no. 8 (August 2016): 541–53. http://dx.doi.org/10.1139/cjz-2015-0260.
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Hippocampus, one of the parts included in the limbic system, is involved in various functions such as learning, memory, food-storing behavior, and sexual discrimination. Neuronal classes of the hippocampal complex in food-storing birds have been also reported, but the study lacks details pertaining to neuronal characteristics and the spine density of the neurons in different subfields of the hippocampus. Hence, the present study was undertaken with the aim to explore the morphology of neurons and the spines present on their dendrites within the hippocampal complex of the House Crow (Corvus splendens Vieillot, 1817), a food-storing Indian bird, and to compare it with previously reported nonfood-storing bird species. It was observed that the hippocampus of C. splendens harbors diverse neuronal classes with substantial percentages of pyramidal neurons, well-developed local circuit neurons, and high spine density. All these neuronal specializations in C. splendens can be related with the food-storing behavior of the bird, which itself is an advantage over nonfood-storing birds.
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Crisol-Martínez, Eduardo, Laura T. Moreno-Moyano, and Finbarr G. Horgan. "Bioacoustics Reveal Species-Rich Avian Communities Exposed to Organophosphate Insecticides in Macadamia Orchards." Birds 1, no. 1 (December 14, 2020): 35–52. http://dx.doi.org/10.3390/birds1010005.
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Organophosphates are the most widely used insecticide class in agriculture. The effects of organophosphates on insectivorous birds can potentially reduce the capacity of these birds to regulate insect pest populations as well as jeopardizing the survival of vulnerable bird species in matrix habitats. In this study, we investigated the diversity of birds inhabiting commercial macadamia orchards in Australia and assessed community-wide exposure of birds to an organophosphate insecticide (trichlorfon). We also studied the impact of trichlorfon on arthropods, and how this affected bird activity. We used a novel approach, combining bird acoustic surveys, and three different arthropod trapping devices. Birds and arthropods were surveyed immediately before and after a trichlorfon application, in sprayed and unsprayed orchards, at six different sites. Surveys showed that trichlorfon applications produced no changes in bird activity, either at the species or community level. Only one species (Lichmera indistincta) showed a significant increase in acoustic activity after treatment. These results indicate that several (62) bird species, some of which have been noted as undergoing regional decline, are exposed to trichlorfon applications. Additionally, trichlorfon applications also produced rapid, negative impacts on certain arthropod groups, particularly spiders. Because almost (80%) of the bird species recorded in the study include arthropods in their diets, then arthropod contaminated by trichlorfon are likely consumed by these orchard-dwelling birds. We recommend that pest management should incorporate strategies to reduce wildlife exposure to toxic chemicals to meet the joint goals of crop production and wildlife conservation in structurally complex agricultural habitats.
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Jayakumar, Samidurai, Joothi Paramanandham, Veerapan Duraimurugan, Ambalavanan Sankari, Arunagiri Ramya, Selvaraj Sathiskumar, and Amirthalingam Durga. "Study on Web-Site Attributes and Predatory Efficiency of Dark Tetragnathid Spider in Point Calimere Wildlife and Bird Sanctuary." International Letters of Natural Sciences 62 (March 2017): 11–19. http://dx.doi.org/10.18052/www.scipress.com/ilns.62.11.
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Spiders represent one of the most abundant components of the predatory arthropods in terrestrial ecosystem. Their effectiveness at restricting pest populations, both alone and as part of natural enemy complex has well demonstrated in many countries. The web, web-site attributes and predatory efficiency of Dark Tetragnathid Spider Tetragnatha mandibulata were assessed in Point Calimere Wildlife and Bird Sanctuary between August 2015 and March 2016. In the present study, the spiders used limited number of plants species. The relationship between web architecture and web-site attributes was estimated using Pearson’s correlation. Number of spiders recorded in the web showed the positive correlation with web horizontal and vertical length of the capture areas (p<0.05). Similarly, the web circumference showed the positive interaction with plant height and canopy width (p<0.05), which clearly indicated the importance of vegetations across the webs of Dark Tetragnathid Spider. Further, the microhabitat selection and utilization could also be impacted by non-trophic factors like structural features of plants that provide architectural supports to spiders. A total of 4620 insect pests comprising seven orders were entangled by the webs of dark tetragnathid spiders. Number of spiders in the web were positively correlated with number of insect pests (p<0.05), which clearly explained that the Dark Tetragnathid spiders restricting pest populations and therefore they are considered as useful organism in biological control.
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Butcher, A. R., J. K. Brealey, D. I. Grove, and R. B. Dymock. "Brachylaima cribbi(Digenea: Brachylaimidae): scanning electron microscopical observations of the life-cycle stages." Journal of Helminthology 76, no. 3 (September 2002): 207–15. http://dx.doi.org/10.1079/joh2002119.
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AbstractBrachylaima cribbiis a recently described species of terrestrial trematode that infects mammals and birds with helicid land snails as its first and second intermediate hosts. The adult worm is 2.5–6.0 mm long by 0.5–0.8 mm wide being a long slender cylindrical worm with oral and ventral suckers in the anterior quarter and genital pore in the posterior quarter. Scanning electron microscopy shows that there is a dense covering of tegumental spines at the anterior end which diminishes towards the posterior extremities of the worm. Development of spines was observed in juvenile and mature adult worms. In young worms 1–3 weeks post infection (wpi) spines appear as buds with a serrated edge each having 1–4 spikes per spine. As the worm ages the spines broaden and by 5 wpi the number of spikes per spine increases to an average of 8.1. The serial development of oral sucker papillae in the cercaria, metacercaria and adult worm was observed with the finding of an elongated papilla with a bifurcated tip on the cercaria becoming a shorter and thicker elongated papilla with a large central stoma on the metacercaria. In the adult worm, this papilla becomes dome-shaped with a small central stoma. For some of these papillae a cilium could be seen extended from the central stoma. Other life-cycle stages illustrated were the hatched egg with an extruded egg membrane minus an operculum and a portion of the branched sporocyst dissected from the digestive gland of the land snailTheba pisanashowing a terminal birth pore. Scanning electron microscopy morphological features of the adult worm observed for the first time in aBrachylaimawere the unarmed cirrus extended from the genital pore with released sperm present and the Laurer's canal opening visible in tegumental folds on the dorsal surface approximately 300 μm posterior to the genital pore.
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Preziuso, Silvia. "Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Exhibits High Predicted Binding Affinity to ACE2 from Lagomorphs (Rabbits and Pikas)." Animals 10, no. 9 (August 20, 2020): 1460. http://dx.doi.org/10.3390/ani10091460.
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Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the pandemic COVID-19. The virus infects human cells by binding of the virus spike to the cell receptor ACE2. The crystal structure of SARS-CoV-2 spikes in complex with human ACE2 has recently been solved, and the main amino acid residues involved in the virus–receptor complex have been detected. To investigate the affinity of ACE2 of lagomorphs to the SARS-CoV-2 spike, ACE2 sequences from rabbits and American pikas were compared with human ACE2 and with ACE2 from mammals with different susceptibility to the virus. Models of the complex formed by SARS-CoV-2 spike and ACE2 from lagomorphs and from other mammals were created for comparative studies. ACE2 of lagomorphs showed fewer substitutions than human ACE2 in residues involved in the ACE2-SARS-CoV-2 spike complex, similar to cats. Analysis of the binding interface of the simulated complexes ACE2-SARS-CoV-2 spike showed high affinity of the ACE2 of lagomorphs to the viral spike protein. These findings suggest that the spike of SARS-CoV-2 could bind the ACE2 receptor of lagomorphs, and future studies should investigate the role of lagomorphs in SARS-CoV-2 epidemiology. Furthermore, the risks to humans coming into close contacts with these animals should be evaluated.
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Andrews, Kindra, Scott M. Reed, and Susan E. Masta. "Spiders fluoresce variably across many taxa." Biology Letters 3, no. 3 (April 3, 2007): 265–67. http://dx.doi.org/10.1098/rsbl.2007.0016.
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The evolution of fluorescence is largely unexplored, despite the newfound occurrence of this phenomenon in a variety of organisms. We document that spiders fluoresce under ultraviolet illumination, and find that the expression of this trait varies greatly among taxa in this species-rich group. All spiders we examined possess fluorophores in their haemolymph, but bright fluorescence appears to result when a spider sequesters fluorophores in its setae or cuticle. By sampling widely across spider taxa, we determine that fluorescent expression is labile and has evolved multiple times. Moreover, examination of the excitation and emission properties of extracted fluorophores reveals that spiders possess multiple fluorophores and that these differ among some families, indicating that novel fluorophores have evolved during spider diversification. Because many spiders fluoresce in wavelengths visible to their predators and prey (birds and insects), we propose that natural selection imposed by predator–prey interactions may drive the evolution of fluorescence in spiders.
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Mohanty, Ricky, Bandi Kumar Mallik, and Sandeep Singh Solanki. "Recognition of bird species based on spike model using bird dataset." Data in Brief 29 (April 2020): 105301. http://dx.doi.org/10.1016/j.dib.2020.105301.
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Machałowski, Wysokowski, Tsurkan, Galli, Schimpf, Rafaja, Brendler, et al. "Spider Chitin: An Ultrafast Microwave-Assisted Method for Chitin Isolation from Caribena versicolor Spider Molt Cuticle." Molecules 24, no. 20 (October 16, 2019): 3736. http://dx.doi.org/10.3390/molecules24203736.
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Chitin, as a fundamental polysaccharide in invertebrate skeletons, continues to be actively investigated, especially with respect to new sources and the development of effective methods for its extraction. Recent attention has been focused on marine crustaceans and sponges; however, the potential of spiders (order Araneae) as an alternative source of tubular chitin has been overlooked. In this work, we focused our attention on chitin from up to 12 cm-large Theraphosidae spiders, popularly known as tarantulas or bird-eating spiders. These organisms “lose” large quantities of cuticles during their molting cycle. Here, we present for the first time a highly effective method for the isolation of chitin from Caribena versicolor spider molt cuticle, as well as its identification and characterization using modern analytical methods. We suggest that the tube-like molt cuticle of this spider can serve as a naturally prefabricated and renewable source of tubular chitin with high potential for application in technology and biomedicine.
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Bateman, Philip W., and Patricia A. Fleming. "The influence of web silk decorations on fleeing behaviour of Florida orb weaver spiders, Argiope florida (Aranaeidae)." Canadian Journal of Zoology 91, no. 7 (July 2013): 468–72. http://dx.doi.org/10.1139/cjz-2012-0312.
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Spider web silk decorations may (i) act to attract prey, (ii) be decoys for predators, and (iii) make the web visible to prevent larger animals from destroying them. To disentangle the last two hypotheses, we examined the fleeing response and flight initiation distance (FID) of the Florida orb weaver spider (Argiope florida Chamberlin and Ivie, 1944). Spiders were approached in one of two manners: (1) a “predatory” one mimicking a bird and (2) a “looming” approach mimicking the approach of a large animal. We predicted that if silk decorations had an antipredator function, then the extent of silk decoration would influence whether spiders fled from the predatory approach. However, if the function was primarily a signal to large animals, then all spiders would flee the looming approach, but FID would be influenced by the extent of silk decoration. We found no influence of silk decorations on fleeing behaviour and FID of spiders. Spider fleeing behaviour was, however, influenced by height of the web from the ground. The effects of web height might reflect an adaptive response to a more exposed position and therefore could support either of the two hypotheses tested; however, we have no evidence supporting the role of silk decorations on antipredator responses.
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CARUANA-GALIZIA, PAUL, and NATALINO FENECH. "The importance of spring hunting in Malta on European Turtle-Dove Streptopelia turtur and Common Quail Coturnix coturnix populations." Bird Conservation International 26, no. 1 (March 2016): 29–38. http://dx.doi.org/10.1017/s0959270915000325.
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SummaryThe European Commission’s 1979 Wild Birds Directive bans member states from hunting wild birds during spring, the period during which they are breeding or migrating, as hunting wild birds before they have reproduced is perceived to have a greater effect on bird populations than it would in autumn or winter. Malta is the only European Union member state to allow recreational wild bird hunting in spring, when birds migrate over the country to their European breeding grounds. Malta’s derogation of the European Commission’s ban can only be legally permissible if no alternative solutions to spring hunting exist. Using figures provided by hunters, we show that greater numbers of European Turtle-dove Streptopelia turtur and Common Quail Coturnix coturnix – the two species for which spring hunting is allowed – are hunted in autumn than in spring. We show that statistics on the number of birds hunted in spring, which hunters are legally obliged to provide to authorities, are under-reported: they are not correlated, at times negatively correlated, with data on the daily influxes of birds, and they spike in the final week of the season, consistent with the hypothesis that hunters under-report to avoid reaching quotas which would result in an early season closure. Finally, while there are wide error margins around the numbers, independent annual estimates of turtle-doves hunted in Malta imply spring hunting is a conservation concern beyond the country itself. Each spring, hunters in Malta kill the equivalent of between 2.4% and 4.4% of Europe’s turtle-dove population and 0.4% and 0.5% of its quail population.
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Walter, Monika, Christian Fiedler, Renate Grassl, Manfred Biebl, Reinhard Rachel, X. Lois Hermo-Parrado, Antonio L. Llamas-Saiz, Robert Seckler, Stefan Miller, and Mark J. van Raaij. "Structure of the Receptor-Binding Protein of Bacteriophage Det7: a Podoviral Tail Spike in a Myovirus." Journal of Virology 82, no. 5 (December 12, 2007): 2265–73. http://dx.doi.org/10.1128/jvi.01641-07.
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ABSTRACT A new Salmonella enterica phage, Det7, was isolated from sewage and shown by electron microscopy to belong to the Myoviridae morphogroup of bacteriophages. Det7 contains a 75-kDa protein with 50% overall sequence identity to the tail spike endorhamnosidase of podovirus P22. Adsorption of myoviruses to their bacterial hosts is normally mediated by long and short tail fibers attached to a contractile tail, whereas podoviruses do not contain fibers but attach to host cells through stubby tail spikes attached to a very short, noncontractile tail. The amino-terminal 150 residues of the Det7 protein lack homology to the P22 tail spike and are probably responsible for binding to the base plate of the myoviral tail. Det7 tail spike lacking this putative particle-binding domain was purified from Escherichia coli, and well-diffracting crystals of the protein were obtained. The structure, determined by molecular replacement and refined at a 1.6-Å resolution, is very similar to that of bacteriophage P22 tail spike. Fluorescence titrations with an octasaccharide suggest Det7 tail spike to bind its receptor lipopolysaccharide somewhat less tightly than the P22 tail spike. The Det7 tail spike is even more resistant to thermal unfolding than the already exceptionally stable homologue from P22. Folding and assembly of both trimeric proteins are equally temperature sensitive and equally slow. Despite the close structural, biochemical, and sequence similarities between both proteins, the Det7 tail spike lacks both carboxy-terminal cysteines previously proposed to form a transient disulfide during P22 tail spike assembly. Our data suggest receptor-binding module exchange between podoviruses and myoviruses in the course of bacteriophage evolution.
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Paterson, L., R. A. Sanderson, and S. P. Rushton. "The effects of grazing on spider assemblages in upland heather moorland." Proceedings of the British Society of Animal Science 2005 (2005): 65. http://dx.doi.org/10.1017/s1752756200009765.
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Invertebrates are of particular interest on heather moorlands because of their rapid response to small scale habitat changes. Spiders constitute a variable proportion of the diet of heather moorland bird, mammal and reptile species. Furthermore, spiders may be an important indicator of habitat change resulting from management practices, especially those that exert a large- scale spatial impact, e.g. grazing. The component families and species of spider assemblages indicate, through their differing preference for web attachments and web structure, the vegetation density, height and structure (Marc et al., 1999). This effect may be especially pronounced where continued grazing at a particular stocking rate results in characteristic patterns in the vegetation structure. Species and family specific hunting strategies determine prey type and so the presence of some spider species may indicate the presence of a preferred prey species. This study aims to investigate the effect of grazing with sheep alone or in combination with cattle grazing on an upland heather moorland in the north of England.
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Sazima, Ivan. "Anting behaviour with millipedes by the dendrocolaptid bird Xiphocolaptes albicollis in southeastern Brazil." Biota Neotropica 9, no. 1 (March 2009): 249–52. http://dx.doi.org/10.1590/s1676-06032009000100027.
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Several bird species practice anting. While anting a bird holds an ant or other arthropod that produces toxic or irritating secretions and rubs it on the plumage. Here I describe the White-collared Woodcreeper (Xiphocolaptes albicollis) rubbing its body with millipedes of the orders Spirostreptida and Polydesmida while foraging among banana stumps or at bromeliad clumps in southeastern Brazil. On three occasions I recorded the bird holding a millipede in the bill and rubbing it against its chest, belly, and wings. From time to time the millipede was "chewed", and hammered against the substratum and then rubbed on the plumage again. After a while the millipede was ingested or dropped. Bromeliads harbour a rich fauna that includes mosquitoes, ticks, spiders, and snakes, and some of them may be potential hazards to birds that forage among the accumulated plant debris. The toxic secretions of millipedes may act as a deterrent against some of these hazardous animals, and the woodcreeper's behaviour also reduces the noxiousness of a toxic prey before ingestion.
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Brandley, Nicholas, Matthew Johnson, and Sönke Johnsen. "Aposematic signals in North American black widows are more conspicuous to predators than to prey." Behavioral Ecology 27, no. 4 (January 1, 2016): 1104–12. http://dx.doi.org/10.1093/beheco/arw014.
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Abstract The iconic red hourglass of the black widow spiders (genus Latrodectus) is traditionally considered an aposematic signal, yet experimental evidence is lacking. Here, we present data that suggest that black widow coloration may have evolved to be an aposematic signal that is more conspicuous to their vertebrate predators than to their insect prey. In choice experiments with wild birds, we found that the red-and-black coloration deters potential predators: Wild birds were ~3 times less likely to attack a black widow model with an hourglass than one without. Using visual-system appropriate models, we also found that a black widow’s red-and-black color combo is more apparent to a typical bird than a typical insect. Additionally, an ancestral reconstruction reveals that red dorsal coloration is ancestral in black widows and that at some point some North American widows lost their red dorsal coloration. Behaviorally, differences in red dorsal coloration between 2 North American species are accompanied by differences in microhabitat that affects how often a bird will view a black widow’s dorsal region. All observations are consistent with a cost–benefit trade-off of being more conspicuous to predators than to prey. We suggest that limiting detection by prey may help explain why red and black aposematic signals occur frequently in nature.
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Eeva, Tapio, Simo Veistola, and Esa Lehikoinen. "Timing of breeding in subarctic passerines in relation to food availability." Canadian Journal of Zoology 78, no. 1 (February 28, 2000): 67–78. http://dx.doi.org/10.1139/z99-182.
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We studied timing of breeding in four species of hole-nesting passerines, the Siberian tit (Poecile cinctus), great tit (Parus major), pied flycatcher (Ficedula hypoleuca), and redstart (Phoenicurus phoenicurus), and the abundance of the arthropods in their diet (ground-dwelling spiders, winged insects, foliage-feeding lepidopteran and hymenopteran larvae) in Finnish Lapland for 6-12 years. Densities of the invertebrate groups varied considerably, both seasonally and annually. All the bird species started to breed in early summer, when weather conditions were often poor. At the beginning of the breeding season all species relied on ground-dwelling spiders, whose abundances peaked early and were less variable over the years than those of insects. Abundances and timing of emergence of caterpillars in birch and pine canopies (the major food sources for foliage-gleaners) were highly variable, but each year their abundances peaked in July or August, after the nestling period of the birds. This contrasts with reported cases in deciduous forests at midlatitudes and shows that at our site the birds did not time their nestling period ultimately to coincide with peak food availability. Mean clutch sizes declined seasonally in the tit species and the pied flycatcher but not in the redstart. The number of fledglings did not depend on laying date, except in the Siberian tit, for which dependence of fledgling number on laying date varied among years. Although early broods were not more productive (i.e., greater number of fledglings) than later ones, early breeding is ultimately a necessity for recruitment because of the short subarctic summer. Birds cannot delay breeding in the north because late breeding would shorten the time available for moulting, food-hoarding, and preparation for migration or wintering. Our results show that at the time of egg laying, passerines may receive proximate cues to allow them to predict food conditions during the nestling period. Still, exact prediction of food availability during later phases of nesting is constrained by an inherent discrepancy between warm-blooded birds and poikilothermic invertebrates: once a bird has started egg laying, the subsequent phases follow nearly automatically on certain calendar dates, whereas the development of the arthropods depends on the rate of temperature increase.
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Vickers, Michael E., Madison L. Heisey, and Lisa A. Taylor. "Lack of neophobic responses to color in a jumping spider that uses color cues when foraging (Habronattus pyrrithrix)." PLOS ONE 16, no. 7 (July 29, 2021): e0254865. http://dx.doi.org/10.1371/journal.pone.0254865.
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Chemically defended prey often advertise their toxins with bright and conspicuous colors. To understand why such colors are effective at reducing predation, we need to understand the psychology of key predators. In bird predators, there is evidence that individuals avoid novelty—including prey of novel colors (with which they have had no prior experience). Moreover, the effect of novelty is sometimes strongest for colors that are typically associated with aposematic prey (e.g., red, orange, yellow). Given these findings in the bird literature, color neophobia has been argued to be a driving force in the evolution of aposematism. However, no studies have yet asked whether invertebrate predators respond similarly to novel colors. Here, we tested whether naive lab-raised jumping spiders (Habronattus pyrrithrix) exhibit similar patterns of color neophobia to birds. Using color-manipulated living prey, we first color-exposed spiders to prey of two out of three colors (blue, green, or red), with the third color remaining novel. After this color exposure phase, we gave the spiders tests where they could choose between all three colors (two familiar, one novel). We found that H. pyrrithrix attacked novel and familiar-colored prey at equal rates with no evidence that the degree of neophobia varied by color. Moreover, we found no evidence that either prey novelty nor color (nor their interaction) had an effect on how quickly prey was attacked. We discuss these findings in the context of what is known about color neophobia in other animals and how this contributes to our understanding of aposematic signals.
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Flanders, Aron A., William P. Kuvlesky, Donald C. Ruthven, Robert E. Zaiglin, Ralph L. Bingham, Timothy E. Fulbright, Fidel Hernández, and Leonard A. Brennan. "Effects of Invasive Exotic Grasses on South Texas Rangeland Breeding Birds." Auk 123, no. 1 (January 1, 2006): 171–82. http://dx.doi.org/10.1093/auk/123.1.171.
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AbstractInvasive exotic plants are a major threat to many species of wild birds. When these plants become established and widespread, the floristic composition of native plant communities becomes simplified, which can result in long-term and often irreversible habitat degradation for birds and other animals. Until recently, few studies have focused on the effect of invasive exotic grasses on breeding birds in southwestern rangelands. During the 2001 and 2002 breeding seasons (May-June), we compared the abundance and species richness of breeding birds, native flora, and arthropods on South Texas rangeland plots dominated by native grasses and plots dominated by two invasive exotic grasses, Lehmann lovegrass (Eragrostis lehmanniana) and buffelgrass (Cenchrus ciliaris). Native-grass cover was >400% greater on native-grass sites than on exotic-grass sites. Forb and grass species-richness were higher on native-grass sites. Shrub canopy cover, bare ground, and vegetation height measurements were similar on native-grass and exotic-grass sites. Overall bird abundance was 32% greater on native-grass sites than on exotic-grass sites. Lark Sparrows (Chondestes grammacus) were 73% more abundant on native-grass sites. Four other species—Black-throated Sparrow (Amphispiza bilineata), Northern Mockingbird (Mimus polyglottos), Northern Bobwhite (Colinus virginianus), and Cassin’s Sparrow (Aimophilla cassini)— were 26–70% more abundant on native-grass sites. The guild of birds that foraged on the ground under open brush canopies was almost twice as abundant on native-grass sites. Arthropod abundance was 60% greater on the native-grass site we sampled. Specifically, spiders, beetles, and ants were 42–83% more abundant on a native-grass site than on a buffelgrass site. Compared with rangelands dominated by native vegetation, areas dominated by Lehmann lovegrass and buffelgrass in South Texas appear to provide less suitable habitat for breeding birds, especially for bird species that forage on or near the ground.Efectos de Pastos Invasores Exóticos en las Aves que Nidifican en los Campos de Pastoreo del Sur de Texas
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Monnier, Nilah, Kyoko Higo-Moriguchi, Zhen-Yu J. Sun, B. V. Venkataram Prasad, Koki Taniguchi, and Philip R. Dormitzer. "High-Resolution Molecular and Antigen Structure of the VP8* Core of a Sialic Acid-Independent Human Rotavirus Strain." Journal of Virology 80, no. 3 (February 1, 2006): 1513–23. http://dx.doi.org/10.1128/jvi.80.3.1513-1523.2006.
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ABSTRACT The most intensively studied rotavirus strains initially attach to cells when the “heads” of their protruding spikes bind cell surface sialic acid. Rotavirus strains that cause disease in humans do not bind this ligand. The structure of the sialic acid binding head (the VP8* core) from the simian rotavirus strain RRV has been reported, and neutralization epitopes have been mapped onto its surface. We report here a 1.6-Å resolution crystal structure of the equivalent domain from the sialic acid-independent rotavirus strain DS-1, which causes gastroenteritis in humans. Although the RRV and DS-1 VP8* cores differ functionally, they share the same galectin-like fold. Differences between the RRV and DS-1 VP8* cores in the region that corresponds to the RRV sialic acid binding site make it unlikely that DS-1 VP8* binds an alternative carbohydrate ligand in this location. In the crystals, a surface cleft on each DS-1 VP8* core binds N-terminal residues from a neighboring molecule. This cleft may function as a ligand binding site during rotavirus replication. We also report an escape mutant analysis, which allows the mapping of heterotypic neutralizing epitopes recognized by human monoclonal antibodies onto the surface of the VP8* core. The distribution of escape mutations on the DS-1 VP8* core indicates that neutralizing antibodies that recognize VP8* of human rotavirus strains may bind a conformation of the spike that differs from those observed to date.
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A. Rohaim, Mohammed, Rania F. El Naggar, Ahmed M. Helal, Mahmoud M. Bayoumi, Mohamed A. El-Saied, Kawkab A. Ahmed, Muhammad Z. Shabbir, and Muhammad Munir. "Genetic Diversity and Phylodynamics of Avian Coronaviruses in Egyptian Wild Birds." Viruses 11, no. 1 (January 14, 2019): 57. http://dx.doi.org/10.3390/v11010057.
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Avian coronaviruses (ACoVs) are continuously evolving and causing serious economic consequences in the poultry industry and around the globe. Owing to their extensive genetic diversity and high mutation rates, controlling ACoVs has become a challenge. In this context, the potential contribution of wild birds in the disease dynamics, especially in domesticated birds, remains largely unknown. In the present study, five hundred fifty-seven (n = 557) cloacal/fecal swabs were collected from four different wild bird species from eight Egyptian governorates during 2016 and a total of fourteen positive isolates were used for phylodynamics and evolutionary analysis. Genetic relatedness based on spike (S1) gene demonstrated the clustering of majority of these isolates where nine isolates grouped within Egy/variant 2 (IS/885 genotype) and five isolates clustered within Egy/variant 1 (IS/1494/06 genotype). Interestingly, these isolates showed noticeable genetic diversity and were clustered distal to the previously characterized Egy/variant 1 and Egy/variant 2 in Egyptian commercial poultry. The S1 gene based comparison of nucleotide identity percentages revealed that all fourteen isolates reported in this study were genetically related to the variant GI-23 lineage with 92–100% identity. Taken together, our results demonstrate that ACoVs are circulating in Egyptian wild birds and highlight their possible contributions in the disease dynamics. The study also proposes that regular monitoring of the ACoVs in wild birds is required to effectively assess the role of wild birds in disease spread, and the emergence of ACoVs strains in the country.
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Mohanty, Ricky, Bandi Kumar Mallik, and Sandeep Singh Solanki. "Automatic bird species recognition system using neural network based on spike." Applied Acoustics 161 (April 2020): 107177. http://dx.doi.org/10.1016/j.apacoust.2019.107177.
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Woo, Patrick C. Y., Susanna K. P. Lau, Carol S. F. Lam, Kenneth K. Y. Lai, Yi Huang, Paul Lee, Geraldine S. M. Luk, Kitman C. Dyrting, Kwok-Hung Chan, and Kwok-Yung Yuen. "Comparative Analysis of Complete Genome Sequences of Three Avian Coronaviruses Reveals a Novel Group 3c Coronavirus." Journal of Virology 83, no. 2 (October 29, 2008): 908–17. http://dx.doi.org/10.1128/jvi.01977-08.
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ABSTRACT In this territory-wide molecular epidemiology study of coronaviruses (CoVs) in Hong Kong involving 1,541 dead wild birds, three novel CoVs were identified in three different bird families (bulbul CoV HKU11 [BuCoV HKU11], thrush CoV HKU12 [ThCoV HKU12], and munia CoV HKU13 [MuCoV HKU13]). Four complete genomes of the three novel CoVs were sequenced. Their genomes (26,396 to 26,552 bases) represent the smallest known CoV genomes. In phylogenetic trees constructed using chymotrypsin-like protease (3CLpro), RNA-dependent RNA polymerase (Pol), helicase, spike, and nucleocapsid proteins, BuCoV HKU11, ThCoV HKU12, and MuCoV HKU13 formed a cluster distantly related to infectious bronchitis virus and turkey CoV (group 3a CoVs). For helicase, spike, and nucleocapsid, they were also clustered with a CoV recently discovered in Asian leopard cats, for which the complete genome sequence was not available. The 3CLpro, Pol, helicase, and nucleocapsid of the three CoVs possessed higher amino acid identities to those of group 3a CoVs than to those of group 1 and group 2 CoVs. Unique genomic features distinguishing them from other group 3 CoVs include a distinct transcription regulatory sequence and coding potential for small open reading frames. Based on these results, we propose a novel CoV subgroup, group 3c, to describe this distinct subgroup of CoVs under the group 3 CoVs. Avian CoVs are genetically more diverse than previously thought and may be closely related to some newly identified mammalian CoVs. Further studies would be important to delineate whether the Asian leopard cat CoV was a result of interspecies jumping from birds, a situation analogous to that of bat and civet severe acute respiratory syndrome CoVs.
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Strannegård, Claes, Wen Xu, Niklas Engsner, and John A. Endler. "Combining Evolution and Learning in Computational Ecosystems." Journal of Artificial General Intelligence 11, no. 1 (January 1, 2020): 1–37. http://dx.doi.org/10.2478/jagi-2020-0001.
Full textAbstract:
AbstractAlthough animals such as spiders, fish, and birds have very different anatomies, the basic mechanisms that govern their perception, decision-making, learning, reproduction, and death have striking similarities. These mechanisms have apparently allowed the development of general intelligence in nature. This led us to the idea of approaching artificial general intelligence (AGI) by constructing a generic artificial animal (animat) with a configurable body and fixed mechanisms of perception, decision-making, learning, reproduction, and death. One instance of this generic animat could be an artificial spider, another an artificial fish, and a third an artificial bird. The goal of all decision-making in this model is to maintain homeostasis. Thus actions are selected that might promote survival and reproduction to varying degrees. All decision-making is based on knowledge that is stored in network structures. Each animat has two such network structures: a genotype and a phenotype. The genotype models the initial nervous system that is encoded in the genome (“the brain at birth”), while the phenotype represents the nervous system in its present form (“the brain at present”). Initially the phenotype and the genotype coincide, but then the phenotype keeps developing as a result of learning, while the genotype essentially remains unchanged. The model is extended to ecosystems populated by animats that develop continuously according to fixed mechanisms for sexual or asexual reproduction, and death. Several examples of simple ecosystems are given. We show that our generic animat model possesses general intelligence in a primitive form. In fact, it can learn simple forms of locomotion, navigation, foraging, language, and arithmetic.
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Onu, P. N. "Evaluation of two herbal spices as feed additives for finisher broilers." Biotehnologija u stocarstvu 26, no. 5-6 (2010): 383–92. http://dx.doi.org/10.2298/bah1006383o.
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The aim of this study was to evaluate the effect of two herbal spices as feed additives for finisher broilers. 120 5-week old birds were randomly assigned to four treatments in a completely randomized design. Each group was further subdivided into three replicates of 10 birds per replicate. Four experimental diets were formulated such that diet I (T1) which served as the control contained neither ginger nor garlic. Diets 2 (T2) and 3 (T3) contained 0.25% garlic and ginger respectively. Diet 4 (T4) contained a combination of 0.25% of garlic and ginger. Response parameters evaluated include weight gain, feed intake, feed conversion ratio, blood parameters and carcass characteristics. The experiment lasted for 35 days. Results showed that birds fed supplemented diets had significantly (P<0.05) higher body weight gain and superior feed conversion ratio than birds fed the control diet. There was no significant (P>0.05) difference in the feed consumption of the birds among the treatments. The hematological indices, serum biochemistry and carcass characteristics of the birds among the treatment were not significantly (P>0.05) influenced by the dietary treatments. The results of this study suggest that ginger and garlic can be included in broiler finisher diets without adversely affecting the performance of the birds.
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Qian, Zhaohui, Xiuyuan Ou, Luiz Gustavo Bentim Góes, Christina Osborne, Anna Castano, Kathryn V. Holmes, and Samuel R. Dominguez. "Identification of the Receptor-Binding Domain of the Spike Glycoprotein of Human Betacoronavirus HKU1." Journal of Virology 89, no. 17 (June 17, 2015): 8816–27. http://dx.doi.org/10.1128/jvi.03737-14.
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ABSTRACTCoronavirus spike (S) glycoproteins mediate receptor binding, membrane fusion, and virus entry and determine host range. Murine betacoronavirus (β-CoV) in group A uses the N-terminal domain (NTD) of S protein to bind to its receptor, whereas the β-CoVs severe acute respiratory syndrome CoV in group B and Middle East respiratory syndrome CoV in group C and several α-CoVs use the downstream C domain in their S proteins to recognize their receptor proteins. To identify the receptor-binding domain in the spike of human β-CoV HKU1 in group A, we generated and mapped a panel of monoclonal antibodies (MAbs) to the ectodomain of HKU1 spike protein. They did not cross-react with S proteins of any other CoV tested. Most of the HKU1 spike MAbs recognized epitopes in the C domain between amino acids 535 and 673, indicating that this region is immunodominant. Two of the MAbs blocked HKU1 virus infection of primary human tracheal-bronchial epithelial (HTBE) cells. Preincubation of HTBE cells with a truncated HKU1 S protein that includes the C domain blocked infection with HKU1 virus, but preincubation of cells with truncated S protein containing only the NTD did not block infection. These data suggest that the receptor-binding domain (RBD) of HKU1 spike protein is located in the C domain, where the spike proteins of α-CoVs and β-CoVs in groups B and C bind to their specific receptor proteins. Thus, two β-CoVs in group A, HKU1 and murine CoV, have evolved to use different regions of their spike glycoproteins to recognize their respective receptor proteins.IMPORTANCEMouse hepatitis virus, a β-CoV in group A, uses the galectin-like NTD in its spike protein to bind its receptor protein, while HCoV-OC43, another β-CoV in group A, uses the NTD to bind to its sialic-acid containing receptor. In marked contrast, the NTD of the spike glycoprotein of human respiratory β-CoV HKU1, which is also in group A, does not bind sugar. In this study, we showed that for the spike protein of HKU1, the purified C domain, downstream of the NTD, could block HKU1 virus infection of human respiratory epithelial cells, and that several monoclonal antibodies that mapped to the C domain neutralized virus infectivity. Thus, the receptor-binding domain of HKU1 spike glycoprotein is located in the C domain. Surprisingly, two β-CoVs in group A, mouse hepatitis virus and HKU1, have evolved to use different regions of their spike glycoproteins to recognize their respective receptors.
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Beligiannis, Nick, and Jan W. Van Strien. "Early posterior negativity in humans to pictures of snakes and spiders: effects of proximity." Experimental Brain Research 238, no. 12 (October 3, 2020): 2795–804. http://dx.doi.org/10.1007/s00221-020-05925-5.
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Abstract Snakes have proven to drive early attentional capture due to their evolutionary importance, as reflected by the early posterior negativity (EPN). The EPN snake effect might be partly driven by the proximity of the animal. In this study, by employing full-body (medium shot) and head-focused (close-up) pictures, we investigated whether the relative nearness (proximity) of the animal on the picture affects the snake EPN effect. We presented thirty participants with medium shot and close-up snake, spider and bird pictures in a rapid serial presentation paradigm at a presentation rate of three frames per second. We extracted the mean EPN activity from the 225–330 ms time frame after stimulus onset at the parietal–occipital cluster (PO3, O1, Oz, O2, PO4). The results indicate enhanced EPN for snake pictures as compared to spider and bird pictures. In addition, medium-shot snake pictures elicited higher EPN amplitudes than close-up snake pictures, suggesting that the EPN is higher when local, high spatial frequency attributes are visible. Spatial frequency analysis of the stimuli indicated that medium-shot snake pictures possess more power in the high spatial frequency bands, compared to medium-shot spider and bird pictures.
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Park, Hwi-Geun, and Hyun-Sik Kim. "Mechanism Development and Position Control of Smart Buoy Robot." Journal of Ocean Engineering and Technology 35, no. 4 (August 31, 2021): 305–12. http://dx.doi.org/10.26748/ksoe.2021.043.
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There is a gradual increase in the need for energy charging in marine environments because of energy limitations experienced by electric ships and marine robots. Buoys are considered potential energy charging systems, but there are several challenges, which include the need to maintain a fixed position and avoid hazards, dock with ships and robots in order to charge them, be robust to actions by birds, ships, and robots. To solve these problems, this study proposes a smart buoy robot that has multiple thrusters, multiple docking and charging parts, a bird spike, a radar reflector, a light, a camera, and an anchor, and its mechanism is developed. To verify the performance of the smart buoy robot, the position control under disturbance due to wave currents and functional tests such as docking, charging, lighting, and anchoring are performed. Experimental results show that the smart buoy robot can operate under disturbances and is functionally effective. Therefore, the smart buoy robot is suitable as an energy charging system and has potential in realistic applications.
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Núñez, V., F. Drago, S. Jones, and L. Lunaschi. "Helminth parasites of the endangered hooded grebe,Podiceps gallardoi, from Patagonia Argentina, with the description of two new digenean species." Journal of Helminthology 92, no. 5 (October 4, 2017): 563–71. http://dx.doi.org/10.1017/s0022149x17000827.
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AbstractIn March 2011, a predator killed 33 hooded grebes,Podiceps gallardoiRumboll (Podicipedidae), a critically endangered species, in a nesting colony at El Cervecero Lake, Santa Cruz Province, Argentina. The viscera of ten birds were examined for helminths. Two new species of Trematoda were recovered from the intestines. The plagiorchidPlagiorchis patagonensisn. sp. is mainly characterized by the larger size of the oral sucker relative to the ventral sucker, and by the distribution of the vitellarium in two lateral fields, confluent between the caecal bifurcation and the ventral sucker. The echinostomatidEuparyphium tobianumn. sp. is mainly characterized by possessing a head collar with 37–39 spines (4 angle spines on each ventral lappet, 4 lateral spines in a single row on each side, and 21–23 dorsal spines in a double row). An unidentified cestode, a tetramerid nematode and a notocotylid trematode were also recovered from the birds. This is the first record of helminths parasitizing the hooded grebe.
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Macko, J., M. Špakulová, and A. Macková. "Echinoparyphium limosorum n. sp. (Trematoda: Echinostomatidae) from Black-tailed Godwit, Limosa limosa (Aves, Charadriiformes) in Slovakia." Helminthologia 46, no. 4 (December 1, 2009): 220–24. http://dx.doi.org/10.2478/s11687-009-0041-8.
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AbstractEchinostomatid trematode Echinoparyphium limosorum n. sp. from the charadriiform bird Limosa limosa is described on basis of morphometrical study of museum material. The new species is characterized by medium-sized body up to 4.9 mm long, reniform head collar up to 511 wide, armed with 48–51 collar spines up to 91 µm, arranged in double row. The new species is largely similar to Echinoparyphium recurvatum, however, the most remarkable difference lays in the higher number of collar spines which are 48–51 in E. limosorum n. sp. but 45 in E. recurvatum. The authors discuss relative impact of numerical generic characters and propose an amending of the diagnosis of The genus Echinoparyphium given by Kostadinova (2005) as follows: Collar spines up to 51, sharply pointed, all in double row.
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Park, Eun Jeong, Phyoe Kyawe Myint, Michael Gyasi Appiah, Samuel Darkwah, Siqingaowa Caidengbate, Atsushi Ito, Eri Matsuo, Eiji Kawamoto, Arong Gaowa, and Motomu Shimaoka. "The Spike Glycoprotein of SARS-CoV-2 Binds to β1 Integrins Expressed on the Surface of Lung Epithelial Cells." Viruses 13, no. 4 (April 9, 2021): 645. http://dx.doi.org/10.3390/v13040645.
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The spike glycoprotein attached to the envelope of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) binds to and exploits angiotensin-converting enzyme 2 (ACE2) as an entry receptor to infect pulmonary epithelial cells. A subset of integrins that recognize the arginyl–glycyl–aspartic acid (RGD) sequence in the cognate ligands has been predicted in silico to bind the spike glycoprotein and, thereby, to be exploited for viral infection. Here, we show experimental evidence that the β1 integrins predominantly expressed on human pulmonary epithelial cell lines and primary mouse alveolar epithelial cells bind to this spike protein. The cellular β1 integrins support adhesive interactions with the spike protein independently of ACE2, suggesting the possibility that the β1 integrins may function as an alternative receptor for SARS-CoV-2, which could be targeted for the prevention of viral infections.
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McCoy, Dakota E., Victoria E. McCoy, Nikolaj K. Mandsberg, Anna V. Shneidman, Joanna Aizenberg, Richard O. Prum, and David Haig. "Structurally assisted super black in colourful peacock spiders." Proceedings of the Royal Society B: Biological Sciences 286, no. 1902 (May 15, 2019): 20190589. http://dx.doi.org/10.1098/rspb.2019.0589.
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Male peacock spiders ( Maratus , Salticidae) compete to attract female mates using elaborate, sexually selected displays. They evolved both brilliant colour and velvety black. Here, we use scanning electron microscopy, hyperspectral imaging and finite-difference time-domain optical modelling to investigate the deep black surfaces of peacock spiders. We found that super black regions reflect less than 0.5% of light (for a 30° collection angle) in Maratus speciosus (0.44%) and Maratus karrie (0.35%) owing to microscale structures. Both species evolved unusually high, tightly packed cuticular bumps (microlens arrays), and M. karrie has an additional dense covering of black brush-like scales atop the cuticle. Our optical models show that the radius and height of spider microlenses achieve a balance between (i) decreased surface reflectance and (ii) enhanced melanin absorption (through multiple scattering, diffraction out of the acceptance cone of female eyes and increased path length of light through absorbing melanin pigments). The birds of paradise (Paradiseidae), ecological analogues of peacock spiders, also evolved super black near bright colour patches. Super black locally eliminates white specular highlights, reference points used to calibrate colour perception, making nearby colours appear brighter, even luminous, to vertebrates. We propose that this pre-existing, qualitative sensory experience—‘sensory bias’—is also found in spiders, leading to the convergent evolution of super black for mating displays in jumping spiders.
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Goosey, Hayes B., Joseph T. Smith, Kevin M. O’Neill, and David E. Naugle. "Ground-Dwelling Arthropod Community Response to Livestock Grazing: Implications for Avian Conservation." Environmental Entomology 48, no. 4 (June 24, 2019): 856–66. http://dx.doi.org/10.1093/ee/nvz074.
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Abstract Terrestrial arthropods are a critical component of rangeland ecosystems that convert primary production into resources for higher trophic levels. During spring and summer, select arthropod taxa are the primary food of breeding prairie birds, of which many are imperiled in North America. Livestock grazing is globally the most widespread rangeland use and can affect arthropod communities directly or indirectly through herbivory. To examine effects of management on arthropod community structure and avian food availability, we studied ground-dwelling arthropods on grazed and ungrazed sagebrush rangelands of central Montana. From 2012 to 2015, samples were taken from lands managed as part of a rest-rotation grazing program and from idle lands where livestock grazing has been absent for over a decade. Bird-food arthropods were twice as prevalent in managed pastures despite the doubling of overall activity-density of arthropods in idle pastures. Activity-density on idled lands was largely driven by a tripling of detritivores and a doubling in predators. Predator community structure was simplified on idled lands, where Lycosid spiders increased by fivefold. In contrast, managed lands supported a more diverse assemblage of ground-dwelling arthropods, which may be particularly beneficial for birds in these landscapes if, for example, diversity promotes temporal stability in this critical food resource. Our results suggest that periodic disturbance may enhance arthropod diversity, and that birds may benefit from livestock grazing with periodic rest or deferment.
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Babirat, C., K. N. Mouritsen, and R. Poulin. "Equal partnership: two trematode species, not one, manipulate the burrowing behaviour of the New Zealand cockle, Austrovenus stutchburyi." Journal of Helminthology 78, no. 3 (September 2004): 195–99. http://dx.doi.org/10.1079/joh2003231.
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AbstractMetacercariae of the trematode Curtuteria australis (Echinostomatidae) accumulate in the foot of the New Zealand cockle Austrovenus stutchburyi, severely impairing the cockle's ability to burrow under the sediments. This results in increased predation by birds on cockles, and thus enhanced transmission rates of the parasite to its bird definitive hosts. This host manipulation by the trematode is costly: fish regularly crop the tip of the foot of cockles stranded on the sediment surface, killing any metacercariae they ingest. A second, previously undetected trematode species (characterized by 23 collar spines) co-existing with C. australis, has been found in the foot of cockles in the Otago Harbour, South Island, New Zealand. The relative abundance of the two species varies among localities, with the identity of the numerically dominant species also changing from one locality to the next. Both C. australis and the new species have a strong preference for encysting in the tip of the cockle's foot, where their impact on the burrowing ability of the host is greatest, and where they both face the risk of cropping by fish. Results indicate that these two species are ecological equivalents, and their combined numbers determine how the cockle population is affected.
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De Paula, Jean Henrique Nunes, Juliana Macedo Magnino Silva, Liria Queiroz Luz Hirano, Isabela Vieira Carneiro, Nathana Beatriz Martins, and Rafael Rocha De Souza. "Parasitism by Syngamus trachea in Blue-and-Yellow Macaw (Ara ararauna)." Acta Scientiae Veterinariae 46 (October 4, 2018): 5. http://dx.doi.org/10.22456/1679-9216.87494.
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Background: Ara ararauna is widely distributed in South America and frequently affected by anthropogenic activities and environmental pressures such as illegal bird trafficking, and habitat loss. Also some endoparasites can threaten their health, and cause their death, or prevent the reintroduction of the animal to its natural environment. The objective of the present work was to report the occurrence of parasitism by Syngamus trachea in an Ara ararauna.Case: An adult, 900-gram female Ara ararauna from a project for the rehabilitation of the Brazilian fauna was kept in a collective nursery together with 12 specimens of the same species. Their diet was composed of typical fruits of the region, which were offered twice a day, and water ad libitum. The macaws had no previous history of anthelmintic treatment. The specimen evaluated presented progressive weight loss, constant sneezing, and reduced appetite for seven days. During physical examination the animal presented apathy, lethargy, spiked feathers, body condition score of 1/4, frequent sneezing, and inspiratory dyspnea. After this examination, the bird died, and the necropsy was performed. The postmortem findings were pale periocular, oral, and cloacal mucosae, cachexia, and presence of parasites of round shape, reddish color, with length of approximately 0.5 cm, in the proximal portion of the trachea. Another parasite with the same characteristics, but smaller in size, showing Y shape was found in the body. The trachea also showed colorless mucus and petechial hemorrhages in the proximal and middle portions of the mucosa. These parasites were subjected to morphological analysis in the Laboratory of Microscopy of the University Center of Triângulo and were identified as Syngamus trachea.Discussion: The diagnosis was based on morphological analysis of the parasite. This parasite can be transmitted through infected worms, which are paratenic hosts of S. trachea. Chickens may also be parasitized by S. trachea; consequently, they may have contributed to the dispersion of eggs of S. trachea in the environment, since they had free access to the entire rural property. There is a positive correlation between parasitism by S. trachea and body condition loss in other bird species that may be connected to the lowering of its feed conversion and food consumption. The mechanical irritation caused by parasites in the tracheal lumen was probably the cause of the clinical manifestations involving the respiratory tract, which were characterized by dyspnea and sneezing. Moreover, petechial hemorrhages, increased mucus production within the trachea, and paleness of the visible mucosa are alterations probably caused by traumatic action and the hematophagous habit of the nematode in the trachea of the bird. Climatic and soil conditions can favor the maintenance of S. trachea eggs and larvae and the permanence of the verminosis in the environment. Therefore, a strict sanitary control of the animals in conservation projects is necessary, with a routine of coproparasitological examinations. Although the actual epidemiological status of endoparasites in free-living Ara ararauna is unknown, deworming protocols for birds intended for release in natural environments are different from those used in specimens under observation. Birds that will return to free life receive antiparasites only in cases of clinical symptomatology associated with positive tests of verminoses to maintain the natural resistance of the birds to the parasites found in their natural environment. The results of this report, showing the occurrence of infection of Ara ararauna by Syngamus trachea denotes the importance of periodic coproparasitological exams.
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Trask, Shane D., Irene S. Kim, Stephen C. Harrison, and Philip R. Dormitzer. "A Rotavirus Spike Protein Conformational Intermediate Binds Lipid Bilayers." Journal of Virology 84, no. 4 (December 9, 2009): 1764–70. http://dx.doi.org/10.1128/jvi.01682-09.
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ABSTRACT During rotavirus entry, a virion penetrates a host cell membrane, sheds its outer capsid proteins, and releases a transcriptionally active subviral particle into the cytoplasm. VP5*, the rotavirus protein believed to interact with the membrane bilayer, is a tryptic cleavage product of the outer capsid spike protein, VP4. When a rotavirus particle uncoats, VP5* folds back, in a rearrangement that resembles the fusogenic conformational changes in enveloped-virus fusion proteins. We present direct experimental evidence that this rearrangement leads to membrane binding. VP5* does not associate with liposomes when mounted as part of the trypsin-primed spikes on intact virions, nor does it do so after it has folded back into a stably trimeric, low-energy state. But it does bind liposomes when they are added to virions before uncoating, and VP5* rearrangement is then triggered by addition of EDTA. The presence of liposomes during the rearrangement enhances the otherwise inefficient VP5* conformational change. A VP5* fragment, VP5CT, produced from monomeric recombinant VP4 by successive treatments with chymotrypsin and trypsin, also binds liposomes only when the proteolysis proceeds in their presence. A monoclonal antibody that neutralizes infectivity by blocking a postattachment entry event also blocks VP5* liposome association. We propose that VP5* binds lipid bilayers in an intermediate conformational state, analogous to the extended intermediate conformation of enveloped-virus fusion proteins.
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Partridge, Lynda J., Lucy Urwin, Martin J. H. Nicklin, David C. James, Luke R. Green, and Peter N. Monk. "ACE2-Independent Interaction of SARS-CoV-2 Spike Protein with Human Epithelial Cells Is Inhibited by Unfractionated Heparin." Cells 10, no. 6 (June 7, 2021): 1419. http://dx.doi.org/10.3390/cells10061419.
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Coronaviruses such as SARS-CoV-2, which is responsible for COVID-19, depend on virus spike protein binding to host cell receptors to cause infection. The SARS-CoV-2 spike protein binds primarily to ACE2 on target cells and is then processed by membrane proteases, including TMPRSS2, leading to viral internalisation or fusion with the plasma membrane. It has been suggested, however, that receptors other than ACE2 may be involved in virus binding. We have investigated the interactions of recombinant versions of the spike protein with human epithelial cell lines that express low/very low levels of ACE2 and TMPRSS2 in a proxy assay for interaction with host cells. A tagged form of the spike protein containing the S1 and S2 regions bound in a temperature-dependent manner to all cell lines, whereas the S1 region alone and the receptor-binding domain (RBD) interacted only weakly. Spike protein associated with cells independently of ACE2 and TMPRSS2, while RBD required the presence of high levels of ACE2 for interaction. As the spike protein has previously been shown to bind heparin, a soluble glycosaminoglycan, we tested the effects of various heparins on ACE2-independent spike protein interaction with cells. Unfractionated heparin inhibited spike protein interaction with an IC50 value of <0.05 U/mL, whereas two low-molecular-weight heparins were less effective. A mutant form of the spike protein, lacking the arginine-rich putative furin cleavage site, interacted only weakly with cells and had a lower affinity for unfractionated and low-molecular-weight heparin than the wild-type spike protein. This suggests that the furin cleavage site might also be a heparin-binding site and potentially important for interactions with host cells. The glycosaminoglycans heparan sulphate and dermatan sulphate, but not chondroitin sulphate, also inhibited the binding of spike protein, indicating that it might bind to one or both of these glycosaminoglycans on the surface of target cells.
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Zhang, Feilong, Lei Jiang, and Shutao Wang. "Repairable cascaded slide-lock system endows bird feathers with tear-resistance and superdurability." Proceedings of the National Academy of Sciences 115, no. 40 (September 17, 2018): 10046–51. http://dx.doi.org/10.1073/pnas.1808293115.
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Bird feathers have aroused tremendous attention for their superdurability against tears during long flights through wind and even bushes. Although feathers may inevitably be unzipped, the separated feather vanes can be repaired easily by bill stroking. However, the mechanism underlying bird feathers’ superdurability against tears remains unclear. Here, we reveal that the superdurability of bird feathers arises from their repairable cascaded slide-lock system, which is composed of hooklets, a slide rail, and spines at the end of the slide rail as terminating structures. Microscopy with a micronano manipulating system and 3D X-ray microscopy provided high-level visibility into the 3D fine structures and the entire unzipping process of feathers. The hooklets can slide along the slide rail reversibly when suffering external forces, and the sliding hooklet can be locked by the spine at the ends of barbules when larger pulling forces are applied and even slide farther away due to the unzipping of the interlocking structure with large deformation of the barbules. The elongation before separation of adjacent barbs can reach up to 270%, and the separation force can be maintained above 80% of the initial value even after 1,000 cycles of separating and repairing. These results prove that the cascaded slide-lock system ensures the superdurability of bird feathers against tears.
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Alex, Scaria, and T. Dhiliphan Rajkumar. "Adaptive Spider Bird Swarm Algorithm-Based Deep Recurrent Neural Network for Malicious JavaScript Detection Using Box-Cox Transformation." International Journal of Open Source Software and Processes 11, no. 4 (October 2020): 46–59. http://dx.doi.org/10.4018/ijossp.2020100103.
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JavaScript is a scripting language that is commonly used in the web pages for providing dynamic functionality in order to enhance user experience. Malicious JavaScript in webpages on internet is an important security issue due to their potentially and universality severe impact. Finding the malicious JavaScript is usually more difficult and time-consuming task in the research community. Hence, an adaptive spider bird swarm algorithm-based deep recurrent neural network (adaptive SBSA-based deep RNN) is proposed for detecting the malicious JavaScript codes in web applications. However, the proposed adaptive SBSA is designed by integrating the adaptive concept with the bird swarm algorithm (BSA) and spider monkey optimization (SMO). With the deep RNN classifier, the complexity issues exists in detecting the malicious codes is effectively resolved through the process of hierarchical computation. Due to the efficiency of the proposed approach, it can evaluate under large real-life datasets.
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Clench, M. H., V. M. Pineiro-Carrero, and J. R. Mathias. "Migrating myoelectric complex demonstrated in four avian species." American Journal of Physiology-Gastrointestinal and Liver Physiology 256, no. 3 (March 1, 1989): G598—G603. http://dx.doi.org/10.1152/ajpgi.1989.256.3.g598.
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The migrating myoelectric complex (MMC) is demonstrated in four avian species: three gallinaceous birds (Gallus, Phasianus, Coturnix) and an owl (Strix). The complex in birds is strikingly similar to the MMC that is known in mammalian species. It has the same basic pattern of quiescence, followed by a period of irregular spike activity, then a period of intense regular spike activity, and finally a return to quiescence. The frequency and duration of avian MMCs are similar to those of mammals, but the propagation velocity and slow-wave frequency are slower. Granivorous birds (Gallus, Phasianus) and carnivores (Strix) exhibit the same basic motility patterns whether in the fed or fasted states. Interspecific differences occur, however, in the details of frequency, propagation velocity, duration, and slow-wave frequency. The closely related galliforms (chickens, pheasants) are more similar to each other in MMC characteristics than either is to the more distantly related owls.
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Ramírez-Salinas, Gema Lizbeth, Marlet Martínez-Archundia, José Correa-Basurto, and Jazmín García-Machorro. "Repositioning of Ligands That Target the Spike Glycoprotein as Potential Drugs for SARS-CoV-2 in an In Silico Study." Molecules 25, no. 23 (November 29, 2020): 5615. http://dx.doi.org/10.3390/molecules25235615.
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The worldwide health emergency of the SARS-CoV-2 pandemic and the absence of a specific treatment for this new coronavirus have led to the use of computational strategies (drug repositioning) to search for treatments. The aim of this work is to identify FDA (Food and Drug Administration)-approved drugs with the potential for binding to the spike structural glycoprotein at the hinge site, receptor binding motif (RBM), and fusion peptide (FP) using molecular docking simulations. Drugs that bind to amino acids are crucial for conformational changes, receptor recognition, and fusion of the viral membrane with the cell membrane. The results revealed some drugs that bind to hinge site amino acids (varenicline, or steroids such as betamethasone while other drugs bind to crucial amino acids in the RBM (naldemedine, atovaquone, cefotetan) or FP (azilsartan, maraviroc, and difluprednate); saquinavir binds both the RBM and the FP. Therefore, these drugs could inhibit spike glycoprotein and prevent viral entry as possible anti-COVID-19 drugs. Several drugs are in clinical studies; by focusing on other pharmacological agents (candesartan, atovaquone, losartan, maviroc and ritonavir) in this work we propose an additional target: the spike glycoprotein. These results can impact the proposed use of treatments that inhibit the first steps of the virus replication cycle.
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Perrella, Fulvio, Federico Coppola, Alessio Petrone, Chiara Platella, Daniela Montesarchio, Annarita Stringaro, Giampietro Ravagnan, Maria Pia Fuggetta, Nadia Rega, and Domenica Musumeci. "Interference of Polydatin/Resveratrol in the ACE2:Spike Recognition during COVID-19 Infection. A Focus on Their Potential Mechanism of Action through Computational and Biochemical Assays." Biomolecules 11, no. 7 (July 16, 2021): 1048. http://dx.doi.org/10.3390/biom11071048.
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In the search for new therapeutic strategies to contrast SARS-CoV-2, we here studied the interaction of polydatin (PD) and resveratrol (RESV)—two natural stilbene polyphenols with manifold, well known biological activities—with Spike, the viral protein essential for virus entry into host cells, and ACE2, the angiotensin-converting enzyme present on the surface of multiple cell types (including respiratory epithelial cells) which is the main host receptor for Spike binding. Molecular Docking simulations evidenced that both compounds can bind Spike, ACE2 and the ACE2:Spike complex with good affinity, although the interaction of PD appears stronger than that of RESV on all the investigated targets. Preliminary biochemical assays revealed a significant inhibitory activity of the ACE2:Spike recognition with a dose-response effect only in the case of PD.