Academic literature on the topic 'Heterometrus'

Two new species of scorpions belonging to the genera Mesobuthus (Buthidae) and Heterometrus (Scorpionidae) are described, based on material collected in the region of Pulan, Chinese Tibet (Himalaya). The first, Mesobuthus songi sp. n., is characterized by moderate to large size (with respect to the genus), general coloration reddish-yellow to reddish brown, carinae and granulations strongly marked, and body and pedipalps with very intense setation. The second, Heterometrus tibetanus sp. n. is characterized by moderate size (with respect to the genus), general coloration from reddish-yellow to reddish-brown, pedipalps strongly elongated, and second metasomal segment longer than wide.

Twospecies of scorpions ( Arachnida : Scorpiones) viz., LychaslaevifronsPocock and Heterometrus flavimanus (Pocock) are reported for the first time form Kerala and an illustrated key to the genera and checklist of scorpion species of Kerala are provided. Currently 21species under 09genera of scorpions are known from the state.

A cladistic analysis of relationships among the genera of Scorpionidae Latreille, 1802—Heterometrus Ehrenberg, 1828; Opistophthalmus C. L. Koch, 1837; Pandinus Thorell, 1876; and Scorpio Linnaeus, 1758—based on morphology and DNA sequence data from loci of three genes in the mitochondrial genome (12S ribosomal DNA (rDNA), 16S rDNA and cytochrome oxidase I) and one gene in the nuclear genome (28S rDNA) is presented. The analysis makes use of exemplar species, specifically selected to test the monophyly of the genera, rather than supraspecific terminal taxa. Other methods used in the analysis are justified in the context of a discussion of current methods for phylogenetic reconstruction. Relationships among the scorpionid genera are demonstrated to be as follows: (Opistophthalmus (Scorpio (Heterometrus + Pandinus))). This reconstruction identifies Opistophthalmus as the basal lineage of the Scorpionidae, rather than the sister-group of Scorpio. Revised descriptions, diagnoses and a key to identification of the four scorpionid genera are provided, together with a summary of what is known about their ecology, distribution and conservation status.

Из яда скорпиона Heterometrus laoticus выделены низкомолекулярные соединения, обладающие антикоагулянтной активностью. Исследование структуры выделенных соединений методами ядерного магнитного резонанса и масс-спектрометрии показало, что одно из них является аденозином, а два других представляют собой дипептиды лейцил-триптофан и изолейцил-триптофан. Наличие в яде скорпиона лейцил-триптофана и изолейцил-триптофана и их способность замедлять свёртывание крови установлены впервые.

Despite intensive research, cancer incidence and mortality continue to rise. Consequently, the necessity to develop effective anti-cancer therapy is apparent. We have recently shown that the gut bacteria of animals living in polluted environments, such as crocodiles, are a potential source of novel anti-tumor molecules. To extend this work to other resilient species, we investigated the anti-tumor effects of gut bacteria of Heterometrus spinifer (a scorpion). Bacteria from the feces and gut were isolated, identified and evaluated for their anti-tumor effects. Bacterial-conditioned media was prepared in Roswell Park Memorial Institute (RPMI) 1640 media, and cytotoxicity and growth inhibitory properties were examined against cervical (HeLa) cancer cells. Liquid chromatography–mass spectrometry (LC-MS) was conducted to establish the identity of the molecules. Eighteen bacteria species from the gut (HSG01-18) and ten bacteria species from feces (HSF01-10) were tested for anti-tumor effects. Bacterial-conditioned media from scorpion gut and feces exhibited significant growth inhibitory effects against HeLa cells of 66.9% and 83.8%, respectively. Microscopic analysis of cancer cells treated with conditioned media HSG12 and HSG16 revealed apoptosis-like effects. HSG12 was identified as Pseudomonas aeruginosa and HSG16 was identified as Bacillus subtilis. Both conditioned media exhibited 100% growth inhibitory effects versus a selection of cancer cells, comprising cervical, breast and prostate cancer cells. LC–MS indicated the presence of 72 and 38 compounds, detected from HSG12 and HSG16, respectively. Out of these compounds, 47 were successfully identified while the remainder were unidentified and are possibly novel. This study suggests that the fecal and gut microbiota of scorpions might possess molecules with anti-cancer properties, however, further intensive research is needed to assess these expectations.

Introduction Heteromeric amino acid transporters (HATs) are composed of a heavy subunit (rBAT or 4F2hc) and a light subunit (b0 + AT, ASC1, LAT1, LAT2, y + LAT1, y + LAT2 and xCT), joined by a disulfide bridge (Chillaron et al. 2001). rBAT and 4F2hc are type II membrane glycoproteins (N-terminal cytoplasmic). Both have a single transmembrane segment, an N-terminal intracellular tail and an extracellular domain (ectodomain). As far as we know, the role of the heavy subunit is facilitating the transit of the light subunit to the plasma membrane. The light subunits are polytopic proteins unglycosylated, with 12 transmembrane segments, and the N-and C-terminal intracellular. The light subunit is the catalytically active subunit which confers specificity to the heterodimer on the transport system (Reig et al. 2002): LAT1 and LAT2 for system L , y+LAT1 and y+LAT2 for system y + L, asc for system ASC1; xCT for system Xc -, and b0+at for system b0, + (Chillaron et al. 2001). Results Overexpression of these human proteins was carried out with the methylotrophic yeast Pichia pastoris (strain KM71H) as expression system (based on Long et al. 2005). The main objective was to generate enough protein in a high level of purity to study the structure and check their function by transport assays. The different subunits, light and heavy, were cloned into the expression vector pPICZ (Invitrogen). To facilitate the purification of the different proteins, a cluster of 10 histidines was introduced by PCR at the N-terminus of the heavy subunits and a StrepTagII (IBA) at the N-terminus of the light subunits. 4F2hc is a glycoprotein with 4 possible targets for glycosylation. The glycosylations confer heterogeneity to protein, thus glycosylation targets were eliminated by directed mutagenesis. From all these human heavy and light subunits and heterodimers, only 4F2hc for the heavy subunits, LAT2 for the light subunits, and the heterodimer 4F2hc/LAT2 were overexpressed and extracted from the yeast membrane in enough amounts to continue with the purification step. The light subunit LAT2 was successfully purified but when the stability was analysed by size exclusion chromatography showed a clear profile of aggregation, concluding further studies. In contrast, the heavy subunit 4F2hc was stable after the exclusion chromatography for two days. The heterodimer 4F2hc/LAT2 proved to be stable after gel filtration analysis during one day. Thus, the heterodimer was significantly more stable than the light subunit alone, which allowed us to make an important statement. The catalytic subunit LAT2 needed their heavy subunit (i.e. 4F2hc) to increase the stability. This statement contrasted with the results for the heterodimer rBAT/b0+AT, in which was the heavy subunit rBAT the one who needed its light subunit b0+AT to a correct folding during its biogenesis (Bartoccioni et al. 2008; Rius et al. 2011). Functional studies with human heterodimer 4F2hc/LAT2 were set up to check the role of 4F2hc in the transport. Firstly the functionality of the heterodimer 4F2hc/LAT2 and the light subunit LAT2 in the living cell was checked successfully, meaning a correct folding at expression level. The apparent KM in both cases was the same, remaining unanswered the role of the heavy subunit 4F2hc in the transport function. Next, reconstitution in liposomes was carried out successfully for 4F2hc/LAT2 but not for LAT2, due to the high aggregation tendency. 4F2hc/LAT2 showed the typical overshoot for an amino acid transporter. To carry out the structural studies and due to the difficulty to maintain a stable soluble heterodimer, it was decided to carry out the technique of Single particle -negative staining (SP-NS) in the laboratory of Prof. Fotiadis in the University of Bern (Switzerland). The 3D model technique based on transmission electron microscopy (TEM) is relatively new and has been imposed for mammalian membrane proteins, allowing structural analysis with relatively small concentration of protein. The pure heterodimer was stained in a grid with uranyl formate at 0.75% (two drops optimized for 1 second, washing with water twice). This sample was analysed by transmission electron microscopy (TEM). Different images of projections in different orientations for 4F2hc/LAT2 were kept in a library of 11,000 picks. The refinement of the whole library allowed the 3D reconstruction of this protein by Mr. Meury. The model showed two asymmetric particles, one smaller, in which the crystal of the human ectodomain 4F2hc (Fort et al. 2007) fitted pretty well, and other bigger, which showed a black hole. Thus, the smaller particle was recognized as the heavy subunit, located on top of the light subunit. The resolution was 19 amstrongs, which was in the normal range for this method (from 16 amstrongs to 25 amstrongs). Discussion It was observed that the heavy subunit was located on top of the light subunit LAT2, and not in contact with the cell membrane as was firstly though. The size for the heavy subunit coincided with the existing 3D crystals of the human ectodomain which can fit quite accurately, always assuming the presence of the transmembrane segment in the 3D model. By contrast, the light subunit did not fit with the crystal structure of the prokaryotic homolog AdiC in the APA family (APC superfamily) (Gao et al. 2009) (Kowalczyk et al. 2011) due to the large amount of detergent surrounding this highly hydrophobic subunit in SP-NS method. In spite of that, when the size was compared with AdiC and Stet (a prokaryotic homolog in the LAT family with 30% of homology) studied in the same SP-NS method (Casagrande et al. 2009) the light subunit LAT2 coincided in size with its homologs, demonstrating that the increased volume was due to the detergent effect. Supporting the 4F2hc/LAT2 model, interaction studies with integrins (Feral et al 2005; Feral et al. 2007) and other membrane proteins involved in cell growth (ICAMI; Liu et al. 2003) and / or overexpressed in tumours (CD147/MCT1; Xu et al. 2005) suggest an effect in the transport function through the heavy subunit 4F2hc, which may be explained with an orientation on top of the light subunit and interaction by the external loops. New Evidences: Recently, the 4F2hc/LAT2 heterodimer model in which the heavy subunit is located on top of the light subunit has been corroborated by cross-linking experiments by Miss Helena Alvarez in our laboratory. This fact, allow us to imagine how interactions between both subunits will carry out also when the disulphide bridge is missing. Analyzing the external loops in AdiC atomic structure (the closest paradigm with LATs at present) is found that the external loop 3 and the external loop 4 are the longest (around 25 residues). These loops are even longer in LAT2, which make possible the interaction between both subunits being the separation of 16 amstrongs in the 3D model. Both loops have important roles in the transport cycle based in LeuT fold. The external loop 3 has an important movement in the transition from outward-open conformation to occluded-outward conformation due to the tilt of 40o of the transmembrane 6. The external loop 4, moves down to lid the substrate pathway during the transition from occluded-outward conformation to the occluded-inward conformation. Our new 3D model of a human heteromeric aminoacid transporter offers the opportunity to study new aspects about the role of the heavy subunit in the holotransporter. If the external loops join 4F2hc and LAT2 modulating the transport function in presence of other transmembrane proteins, or if 4F2hc only acts as a bollard of a multiproteic complex, rest to be studied in the future.
Els transportadors heteromèrics d'aminoàcids (HATS) de metazous estan formats per una subunitat pesada (4F2hc o rBAT) (N-glicoproteïna amb 1 segment transmembrana i un gran ectodomini en el seu extrem C-terminal), i una subunitat lleugera (d'entre 10) unides covalentment per un pont disulfur, fent aquests transportadors únics entre els metazous. En humans, 6 subunitats lleugeres es troben formant heterodímers amb 4F2hc (LAT1, LAT2, y+ LAT1, y + LAT2, XCT i asc1) i una (b0, + AT) amb rBAT. Els HATs tenen incidència en la salut, ja que mutacions en qualsevol de les subunitats ocasionen aminoacidúries (cistinúria, lisinúria amb intolerància a proteïnes), són receptors virals o estan sobre expressats en cèl • lules tumorals. El nostre grup va determinar l'estructura de l'ectodomini de 4F2hc a 2.1 Å (Fort J et al. 2007), i recentment ha resolt l'estructura d'un homòleg procariota (AdiC d' E. coli, amb ~17% d´homologia) de les subunitats lleugeres a 3.0 Å de resolució (Kowalczyk et al. 2011). Per contra no hi ha informació estructural sobre els holo-transportadors HAT. El present treball ens mostra el primer model estructural a 19 Å d'un transportador HAT humà, el transportador 4F2hc/LAT2. La importància de 4F2hc, a part de tenir un paper important en immunologia, es troba en la seva sobreexpressió en cèl•lules tumorals, el que la converteix en una important diana per a tractaments i desenvolupament de vacunes contra el càncer. El model ens mostra com en aquest transportador, l´ectodomini de 4F2hc està situat sobre LAT2, suggerint interacció amb els bucles extracel•lulars del transportador i nos sols interacció a través del pont disulfur del segment transmembrana com es pensava anteriorment. Aquesta nova topologia explica la necessitat i la importància de que l'ectodomini de 4F2hc formi part de l´heterodímer 4F2hc/LAT2 i presenta un escenari estructural per al paper "chaperone-like" de 4F2hc sobre les subunitats lleugeres.

El presente trabajo de investigación tiene como objetivo analizar el método de “Heterometría e Irregularidad Rítmica” para una mejor comprensión de los ritmos irregulares y para la ejecución de manera correcta en los diferentes instrumentos de percusión, así como en la batería acústica, por parte de los estudiantes del 5to ciclo del curso de Percusión Clásica. Para ello, se utilizó la técnica de la observación, tomando en cuenta la participación de los alumnos del curso en cada sesión con su respectivo monitoreo y retroalimentación por parte del profesor y haciendo uso de los instrumentos de percusión y la batería acústica. Los resultados de la presente investigación demostraron cómo las estrategias didácticas del método “Heterometría e Irregularidad Rítmica” ayudó a los alumnos de Percusión Clásica a una mejor comprensión y a una correcta ejecución de los ritmos irregulares, logrando que ellos puedan identificar los elementos propios de la heterometría y facilitar la lectura de los ejercicios propuestos en el presente trabajo de investigación.

Geographically Albania is divided into two main regions: northern Ghegeria and southern Toskeria. The southern part (Toskeria) consists of two sub-regions, Toske and Laberia. These share many commonalities yet the musical styles of each are distinctly different. The Shkumbini River serves as a boundary between the two main regions, as well as a cultural divide distinguishing the varying musical performances and styles. Monodic music is practiced mainly in the north whilst polyphonic music is most commonly performed in the south. These two diverse systems impact on the folk songs of the two regions making them sound significantly different. In addition, different folk instruments are used in both regions. The instrumental and vocal monodic music of the north (Ghegeria) is based on the modal system, with Dorian, Aeolian, Mixolydian, Phrygian, Lydian, Ionian and Hypolydian modes being used. The songs of the north typically portray important historical events or heroic deeds, while the southern songs are not as nationalistic and cover various social themes. They are in general a lot softer and more melodic in character. The folk music of the south (Toskeria) is based on the pentatonic scale, with significant differences which are noticed within the two sub-regions (Toske and Laberia). The vocal music of the south consists of two, three or four vocal parts singing a capella, although sometimes instrumental accompaniment is added. The polyphonic music of the sub-region of Toske is characterized by imitative elements utilized in both the melodies and rhythms of the songs, providing a sense of thematic unity, whereas in Laberia contrasting elements are more dominant throughout the songs. Despite these differences, iso (or drone) is performed similarly in both sub-regions, and is another important element in the polyphonic music of the south. A notable form of instrumental polyphonic music of Toskeria is that of Kaba, performed by Saze folk ensembles. What distinguishes Albanian polyphonic folk music from its counterparts in other areas of the world is that it has not only survived but is flourishing in modern times. Unlike many other cultures that have excluded polyphonic music from mainstream society, Albanian polyphonic music is known by most Albanians and is well practiced and enjoyed by all age groups, and rural as well as urban Albanians, regardless of their degree of formal musical training
Dissertation (MMus)--University of Pretoria, 2011.
Music
unrestricted

The chapter examines a distinction between isometric music, in which successive metrical cycles are of equal length, and heterometric music, where the length and structure of the cycle can change. In South Asia, most music is isometric. In the classical traditions, each composition normally employs one tāla, in which the length of the cycle is defined by a clap-pattern or instrumental time-line. There are, however, rare cases where the tāla changes in the course of a composition, and such cases are more frequent in the context of religious music, but the origins and purposes of such heterometrical complexity are unclear. Three examples are analyzed from the Hindu-Buddhist traditions of the Kathmandu Valley, Nepal, featuring metrical compression and proportional time spans. The possible significance of “time changes” in these and analogous cases is discussed in relation to cultural meanings, historical antecedents, religious and social behavior, and the cognitive processes of performance.