Relevant bibliographies by topics / Spikenet

Contents

  1. Journal articles
  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers

Academic literature on the topic 'Spikenet'

Author: Grafiati
Published: 4 June 2021
Last updated: 1 February 2022

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Spikenet.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "Spikenet"

1

Thorpe, Simon J., Rudy Guyonneau, Nicolas Guilbaud, Jong-Mo Allegraud, and Rufin VanRullen. "SpikeNet: real-time visual processing with one spike per neuron." Neurocomputing 58-60 (June 2004): 857–64. http://dx.doi.org/10.1016/j.neucom.2004.01.138.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Delorme, Arnaud, Jacques Gautrais, Rufin van Rullen, and Simon Thorpe. "SpikeNET: A simulator for modeling large networks of integrate and fire neurons." Neurocomputing 26-27 (June 1999): 989–96. http://dx.doi.org/10.1016/s0925-2312(99)00095-8.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Delorme, Arnaud, and Simon J. Thorpe. "SpikeNET: an event-driven simulation package for modelling large networks of spiking neurons." Network: Computation in Neural Systems 14, no. 4 (January 2003): 613–27. http://dx.doi.org/10.1088/0954-898x_14_4_301.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Laudencia-Chingcuanco, Debbie, and Sarah Hake. "The indeterminate floral apex1 gene regulates meristem determinacy and identity in the maize inflorescence." Development 129, no. 11 (June 1, 2002): 2629–38. http://dx.doi.org/10.1242/dev.129.11.2629.

Full text
Abstract:
Meristems may be determinate or indeterminate. In maize, the indeterminate inflorescence meristem produces three types of determinate meristems: spikelet pair, spikelet and floral meristems. These meristems are defined by their position and their products. We have discovered a gene in maize, indeterminate floral apex1 (ifa1) that regulates meristem determinacy. The defect found in ifa1 mutants is specific to meristems and does not affect lateral organs. In ifa1 mutants, the determinate meristems become less determinate. The spikelet pair meristem initiates more than a pair of spikelets and the spikelet meristem initiates more than the normal two flowers. The floral meristem initiates all organs correctly, but the ovule primordium, the terminal product of the floral meristem, enlarges and proliferates, expressing both meristem and ovule marker genes. A role for ifa1 in meristem identity in addition to meristem determinacy was revealed by double mutant analysis. In zea agamous1 (zag1) ifa1 double mutants, the female floral meristem converts to a branch meristem whereas the male floral meristem converts to a spikelet meristem. In indeterminate spikelet1 (ids1) ifa1 double mutants, female spikelet meristems convert to branch meristems and male spikelet meristems convert to spikelet pair meristems. The double mutant phenotypes suggest that the specification of meristems in the maize inflorescence involves distinct steps in an integrated process.
APA, Harvard, Vancouver, ISO, and other styles
5

Zając, Tadeusz, Wiesław Szafrański, and Jacek Strojny. "Kernel mass of winter triticale depending on placing position in a spikelet and a spike, with regard to its productiveness." Acta Agrobotanica 57, no. 1-2 (2013): 175–86. http://dx.doi.org/10.5586/aa.2004.017.

Full text
Abstract:
The investigations were carried outin 1996-1997 on degraded chernozem developed from loess. The winter triticale cv. 'Presto' cultivated after 4 forecrops (spring cereals with red clover undersown and triticale in pure stand). Studied were correlation between the number of spikeIets and kernels and their placing position in a spike and spikelet, and the grain weight from three spike size groups. The number of productive spikelets per spike and fertility of inflorescence per spikelet, measured as a number of kernels, were the biggest in big spikes group. Kernels placed in positions 1 and 2 in a kernel had the biggest mass, whereas the kernels developed from the inflorescence in positions 3 and 4 were conspicuous for their smaller mass, particularly in the small and medium-size spike groups. The analysis of correlation coefficient values revealed that grain weight per spike was strongly correlated with the number of kernels per spike in all determined size classes. Also a significant effect of single kemel weight on yield per spike was noticed, but the coefficient value was lower (r=0.30). Spikelets in positions from 3 to 7 level (on both sides of spike) had the greatest share in grain weight per spike for the smallest spike group, whereas for medium- size and big spikes respectively spikelets in positions 3 through 9 and 2 through 10.
APA, Harvard, Vancouver, ISO, and other styles
6

Li, W., S. Yan, and Z. Wang. "Effect of spikelet position on starch proportion, granule distribution and related enzymes activity in wheat grain  ." Plant, Soil and Environment 59, No. 12 (December 1, 2013): 568–74. http://dx.doi.org/10.17221/586/2013-pse.

Full text
Abstract:
The starch proportion, starch granule distribution, and activities of enzymes involved in starch synthesis in different spikelet positions were examined during grain development in two high-yielding winter wheat cultivars. The results showed that grain number and weight per spikelet in different spatial position showed a single-peak curve from the base to the top in a wheat spike. Upper spikelets had the highest starch and amylose proportion followed by basal spikelets, whereas middle spikelets had the lowest. Starch and amylose absolute content was in opposition to their proportion. The volume of B- and A-type granule in grain of middle spikelets was remarkably higher and lower than those of basal and upper spikelets, respectively. However, no significant difference occurred in the number of A- and B-type granule in grains among different spikelet position. Compared with the basal and upper spikelets, the middle spikelets showed higher sucrose and ATP content and activities of starch biosynthetic enzymes, and subsequently higher starch absolute content. The results suggested that superior sucrose providing and degradation capacity and the high activities of enzymes involved in starch synthesis resulted in development of B-type starch granule in grain of middle spikelets.
APA, Harvard, Vancouver, ISO, and other styles
7

Warringa, J. W., P. C. Struik, R. de Visser, and A. D. H. Kreuzer. "The pattern of flowering, seed set, seed growth and ripening along the ear of Lolium perenne." Functional Plant Biology 25, no. 2 (1998): 213. http://dx.doi.org/10.1071/pp96084.

Full text
Abstract:
A greenhouse pot experiment was conducted to elucidate the pattern of decreasing seed set and seed dry weight found from the basal to the upper spikelet in Lolium perenne L. ears and—very markedly—acropetally within a spikelet. The changes in fresh and dry weight of the seed after anthesis were monitored for 12 positions within the ear. To determine the duration of seed growth, the spatial and temporal patterns of flowering and ripening along the ear were assessed. The proximal florets of the central spikelets flowered first, and the upper spikelets in the ear flowered before the basal spikelets, with flowering proceeding acropetally within a spikelet. The upper spikelets ripened earlier than the basal ones, and the seeds within a spikelet ripened simultaneously. These patterns of flowering and ripening along the ear resulted in different durations of seed growth along the ear. Thus from the proximal to the distal seed within a spikelet the duration of growth decreased by 26%, the rate of growth fell by 48% and seed set and seed dry weight also fell sharply. Of the total variation in maximum, final seed dry weight within the ear, 4% could be attributed to the difference in seed dry weight between spikelets and 89% to differences in seed dry weight within spikelets. Differences in duration and rate of seed growth and seed set were also much smaller between spikelets than within spikelets. About 60% of the differences in seed dry weight along the ear were attributable to differences in growth rate and about 30% to differences in the duration of seed growth. The relative growth rate did not differ between seeds in different positions. The main factor determining seed growth rate was the dry weight of the ovule at anthesis, which declined sharply from the proximal to the distal floret within a spikelet. Analysis of the fructose, glucose, sucrose and starch concentrations showed that seed growth was not limited by the availability of sucrose nor by the ability of the seeds to convert sucrose into starch. These conclusions were supported by results from a second greenhouse experiment in which all ovules in 50% of the spikelets were removed at anthesis. Dry weight of the remaining seeds increased by only 15%.
APA, Harvard, Vancouver, ISO, and other styles
8

Panigrahi, Rashmi, Ekamber Kariali, Binay Bhusan Panda, Tanguy Lafarge, and Pravat Kumar Mohapatra. "Controlling the trade-off between spikelet number and grain filling: the hierarchy of starch synthesis in spikelets of rice panicle in relation to hormone dynamics." Functional Plant Biology 46, no. 6 (2019): 507. http://dx.doi.org/10.1071/fp18153.

Full text
Abstract:
The advent of dwarf statured rice varieties enabled a major breakthrough in yield and production, but raising the ceiling of genetically determined yield potential even further has been the breeding priority. Grain filling is asynchronous in the rice panicle; the inferior spikelets particularly on secondary branches of the basal part do not produce grains of a quality suitable for human consumption. Of the various strategies being considered, the control of ethylene production at anthesis has been a valuable route to potentially enhance genetic yield level of rice. The physiology underlying spikelet development has revealed spikelet position-specific ethylene levels determine the extent of grain filling, with higher levels resulting in ill-developed spikelet embodying poor endosperm starch content. To break the yield barrier, breeders have increased spikelet number per panicle in new large-panicle rice plants. However, the advantage of panicles with numerous spikelets has not resulted in enhanced yield because of poor filling of inferior spikelets. High spikelet number stimulates ethylene production and downgrading of starch synthesis, suggesting a trade-off between spikelet number and grain filling. High ethylene production in inferior spikelets suppresses expression of genes encoding endosperm starch synthesising enzymes. Hence, ethylene could be a retrograde signal that dictates the transcriptome dynamics for the cross talk between spikelet number and grain filling in the rice panicle, so attenuation of its activity may provide a solution to the problem of poor grain filling in large-panicle rice. This physiological linkage that reduces starch biosynthesis of inferior kernels is not genetically constitutive and amenable for modification through chemical, biotechnological, surgical and allelic manipulations. Studies on plant genotypes with different panicle architecture have opened up possibilities of selectively improving starch biosynthesis of inferior spikelets and thereby increasing grain yield through a physiological route.
APA, Harvard, Vancouver, ISO, and other styles
9

Panigrahi, Rashmi, Ekamber Kariali, Binay Bhusan Panda, Tanguy Lafarge, and Pravat Kumar Mohapatra. "Corrigendum to: Controlling the trade-off between spikelet number and grain filling: the hierarchy of starch synthesis in spikelets of rice panicle in relation to hormone dynamics." Functional Plant Biology 46, no. 6 (2019): 595. http://dx.doi.org/10.1071/fp18153_co.

Full text
Abstract:
The advent of dwarf statured rice varieties enabled a major breakthrough in yield and production, but raising the ceiling of genetically determined yield potential even further has been the breeding priority. Grain filling is asynchronous in the rice panicle; the inferior spikelets particularly on secondary branches of the basal part do not produce grains of a quality suitable for human consumption. Of the various strategies being considered, the control of ethylene production at anthesis has been a valuable route to potentially enhance genetic yield level of rice. The physiology underlying spikelet development has revealed spikelet position-specific ethylene levels determine the extent of grain filling, with higher levels resulting in ill-developed spikelet embodying poor endosperm starch content. To break the yield barrier, breeders have increased spikelet number per panicle in new large-panicle rice plants. However, the advantage of panicles with numerous spikelets has not resulted in enhanced yield because of poor filling of inferior spikelets. High spikelet number stimulates ethylene production and downgrading of starch synthesis, suggesting a trade-off between spikelet number and grain filling. High ethylene production in inferior spikelets suppresses expression of genes encoding endosperm starch synthesising enzymes. Hence, ethylene could be a retrograde signal that dictates the transcriptome dynamics for the cross talk between spikelet number and grain filling in the rice panicle, so attenuation of its activity may provide a solution to the problem of poor grain filling in large-panicle rice. This physiological linkage that reduces starch biosynthesis of inferior kernels is not genetically constitutive and amenable for modification through chemical, biotechnological, surgical and allelic manipulations. Studies on plant genotypes with different panicle architecture have opened up possibilities of selectively improving starch biosynthesis of inferior spikelets and thereby increasing grain yield through a physiological route.
APA, Harvard, Vancouver, ISO, and other styles
10

Michalikova, Martina, Michiel W. H. Remme, and Richard Kempter. "Extracellular waveforms reveal an axonal origin of spikelets in pyramidal neurons." Journal of Neurophysiology 120, no. 4 (October 1, 2018): 1484–95. http://dx.doi.org/10.1152/jn.00463.2017.

Full text
Abstract:
Spikelets are small spike-like membrane depolarizations measured at the soma whose origin in pyramidal neurons is still unresolved. We investigated the mechanism of spikelet generation using detailed models of pyramidal neurons. We simulated extracellular waveforms associated with action potentials and spikelets and compared these with experimental data obtained by Chorev and Brecht ( J Neurophysiol 108: 1584–1593, 2012) from hippocampal pyramidal neurons in vivo. We considered spikelets originating in the axon of a single cell as well as spikelets generated in two cells coupled with gap junctions. We found that in both cases the experimental data can be explained by an axonal origin of spikelets: in the single-cell case, action potentials are generated in the axon but fail to activate the soma. Such spikelets can be evoked by dendritic input. Alternatively, spikelets resulting from axoaxonal gap junction coupling with a large (greater than several hundred μm) distance between the somata of the coupled cells are also consistent with the data. Our results demonstrate that a cell firing a somatic spikelet generates a detectable extracellular potential that is different from the action potential-correlated extracellular waveform generated by the same cell and recorded at the same location. This, together with the absence of a refractory period between action potentials and spikelets, implies that spikelets and action potentials generated in one cell may easily get misclassified in extracellular recordings as two different cells, albeit they both constitute the output of a single pyramidal neuron. NEW & NOTEWORTHY We addressed the origin of spikelets, using compartmental models of pyramidal neurons. Comparing our simulation results with published extracellular spikelet recordings revealed an axonal origin of spikelets. Our results imply that action potential- and spikelet-associated extracellular waveforms may easily get misclassified as two different cells, albeit they both constitute the output of a single pyramidal cell.
APA, Harvard, Vancouver, ISO, and other styles
More sources

Dissertations / Theses on the topic "Spikenet"

1

Delorme, Arnaud. "Traitement visuel rapide de scènes naturelles chez le singe, l'homme et la machine : une vision qui va de l'avant." Phd thesis, Université Paul Sabatier - Toulouse III, 2000. http://tel.archives-ouvertes.fr/tel-00078924.

Full text
Abstract:
À la frontière entre neurosciences et intelligence artificielle, les neurosciences computationnelles tentent de comprendre les formidables capacités de calcul du cerveau, notamment l'efficacité du traitement de l'image par le système visuel. Mon travail est un double travail expérimental et de modélisation. Dans la partie expérimentale, je tente de déterminer les raisons qui font la précision et la rapidité des processus visuels. On présente brièvement (20-30 ms) des photographies contenant ou non des animaux au sujet qui doit relâcher un bouton quand l'image contient un animal. Le singe macaque réalise cette tâche avec une précision légèrement inférieure à celle de l'homme mais avec une plus grande rapidité. Je tente ensuite de contraindre la catégorisation pour déterminer le rôle à la fois des propriétés intrinsèques des images - couleur, luminance, nombre d'animaux présents, parties visibles de leurs corps, espèce de l'animal... - mais aussi de leurs propriétés extrinsèques - condition de présentation, effet de séquence, familiarité du stimulus, consigne... Bien que certaines conditions accélèrent la catégorisation, les réponses les plus précoces (dont on montre qu'elles ne sont pas spécifiques de certaines images), et les enregistrements EEGs correspondant au traitement de l'image ne sont que très peu affectés. Cela implique donc un traitement rapide massivement parallèle - quasiment automatique - des informations visuelles, où chaque neurone du système visuel peut difficilement émettre plus d'une décharge. À partir de ces contraintes, et de celles imposées par la structure du système visuel, j'ai construit un simulateur biologiquement plausible (SpikeNET) qui permet de simuler le comportement des neurones réels (de la détection de barres orientées jusqu'à la reconnaissance de visages). Les performances de ces modèles sont étonnantes du point de vue du traitement d'image et rivalisent avec les approches classiques en intelligence artificielle.
APA, Harvard, Vancouver, ISO, and other styles
2

Michalikova, Martina. "Mechanisms of spikelet generation in cortical pyramidal neurons." Doctoral thesis, Humboldt-Universität zu Berlin, Lebenswissenschaftliche Fakultät, 2017. http://dx.doi.org/10.18452/17753.

Full text
Abstract:
Unter Spikelets versteht man kleine Depolarisationen mit einer Spike-ähnlichen Wellenform, die man in intrazellulären Ableitungen von verschiedenen Neuronentypen messen kann. In kortikalen Pyramidenzellen wurde ausgeprägte Spikelet-Aktivität nachgewiesen, die erheblich das Membranpotential beeinflussen kann (Crochet et al., 2004; Epsztein et al., 2010; Chorev and Brecht, 2012). Nichtsdestotrotz bleibt der Ursprung von Spikelets in diesen Neuronen unbekannt. In der vorgelegten Arbeit nutzte ich theoretische Modellierung um die Mechanismen von Spikelet-Erzeugung in Pyramidenzellen zu untersuchen. Zuerst sah ich die verschiedenen Hypothesen über den Ursprung von Spikelets durch. In der Literatur entdeckte ich zwei verschiedene Typen von Spikelets. Diese Arbeit konzentriert sich auf den häufiger vorkommenden Typ von Spikelets, welcher durch relativ große Amplituden gekennzeichnet ist. Die Eigenschaften dieser Spikelets passen am besten zu einem axonal Erzeugungsmechanismus. Im zweiten Kapitel widmete ich mich der Hypothese, dass somatische Spikelets axonalen Ursprungs mit somato-dendritischen Inputs hervorgerufen werden können. Ich identifizierte Bedingungen, die es erlauben ein Aktionspotential (AP) am Initialsegment vom Axon (AIS) zu initiieren, welches sich entlang des Axons ausbreitet, aber kein AP im Soma auslöst. Schließlich simulierte ich extrazelluläre Wellenformen von APs und Spikelets und verglich sie mit experimentellen Daten (Chorev and Brecht, 2012). Dieser Vergleich zeigte auf, dass die extrazellulären Wellenformen von Spikelets, die innerhalb einer Zellen am AIS erzeugt werden, gut zu den Daten passen. Zusammenfassend unterstützen meine Ergebnisse die Hypothese, dass Spikelets in Pyramidenzellen am AIS entstehen. Dieser Mechanismus könnte ein Mittel zum Energiesparen bei der Erzeugung von Output-APs sein. Außerdem könnte dadurch die dendritische Plastizität, die auf der Rückwärtspropagierung von APs beruht, reguliert werden.
Spikelets are transient spike-like depolarizations of small amplitudes that can be measured in somatic intracellular recordings of many neuron types. Pronounced spikelet activity has been demonstrated in cortical pyramidal neurons in vivo (Crochet et al., 2004; Epsztein et al., 2010; Chorev and Brecht, 2012), influencing membrane voltage dynamics including action potential initiation. Nevertheless, the origin of spikelets in these neurons remains elusive. In thi thesis, I used computational modeling to examine the mechanisms of spikelet generation in pyramidal neurons. First, I reviewed the hypotheses previously suggested to explain spikelet origin. I discovered two qualitatively different spikelet types described in the experimental literature. This thesis focuses on the more commonly reported spikelet type, characterized by relatively large amplitudes of up to 20 mV. I found that the properties of these spikelets fit best to an axonal generation mechanism. Second, I explored the hypothesis that somatic spikelets of axonal origin can be evoked with somato-dendritic inputs. I identified the conditions allowing these orthodromic inputs to trigger an action potential at the axon initial segment, which propagates along the axon to the postsynaptic targets, but fails to elicit an action potential in the soma and the dendrites. Third, I simulated extracellular waveforms of action potentials and spikelets and compared them to experimental data (Chorev and Brecht, 2012). This comparison demonstrated that the extracellular waveforms of single-cell spikelets of axonal origin are consistent with the data. Together, my results suggest that spikelets in pyramidal neurons might originate at the axon initial segment within a single cell. Such a mechanism might be a way of reducing the energetic costs associated with the generation of output action potentials. Moreover, it might allow to control the dendritic plasticity by backpropagating action potentials.
APA, Harvard, Vancouver, ISO, and other styles
3

Wadsworth, A. C. "Control of spikelet survival in spring barley cv. Maris Mink." Thesis, University of Bristol, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.379532.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Gatica, Roberto Armando 1963. "Caryopsis and spikelet characteristics related to germination behavior in Digitaria californica." Thesis, The University of Arizona, 1995. http://hdl.handle.net/10150/278531.

Full text
Abstract:
Digitaria californica is a warm-season grass native to western hemisphere deserts. This study was conducted to measure: (1) seed dormancy, and the effects of (2) wetting and drying on germination, and (3) glumes on water uptake and loss. Dormancy was measured with weekly germination trials for 12 weeks. Complete and naked caryopses were exposed to a 24-h dry period after 12, 24, 36, and 48-h imbibition, and rewetting for 2 weeks. Water uptake and loss patterns were also measured. Germination percentage increased from about 40% initially to 94% after 9 weeks. Germination speed decreased from 5 days to about 2 days over the same period. Drying reduced percent germination of the 36- and 48-h imbibition treatments for complete caryopses, and that of the 24-, 36-, and 48-h imbibition treatments for naked caryopses. Complete caryopses also seemed to imbibe faster. Moisture loss for complete and naked caryopses appeared similar. Short imbibition periods do not induce germination in this species.
APA, Harvard, Vancouver, ISO, and other styles
5

Julia, Cécile. "Thermal stresses and spikelet sterility in rice : sensitive phases and role of microclimate." Thesis, Montpellier 2, 2012. http://www.theses.fr/2012MON20192/document.

Full text
Abstract:
Les inflorescences de riz sont sensibles au froid et à la chaleur ce qui se traduit par une stérilité des épillets à floraison. Ce n'est cependant pas directement la température de l'air qui est en cause mais la température des tissus à des stades de développement précis. Les stratégies pour faire face au stress thermique sont : 1) la tolérance physiologique d'une variété particulière; 2) l'échappement temporel au stress par l'ajustement de la phénologie et de l'heure de l'anthèse (TOA); 3) l'évitement du stress par le microclimat généré par la culture. Cette thèse a pour but de caractériser l'effet des composantes climatiques sur 2) et 3), et pour ce, le même essai a été mené au champ sur quatre variétés de riz irrigué cultivées dans quatre environnements climatiques contrastés (Philippines, 2 saisons aux Sénégal, France). Bien que peu de différences variétales aient été observées au sein de chaque site, il existe une grande variabilité de l'heure de l'anthèse et de la différence de température (TD) entre panicule (Tp) et air (Tair) en réponse à l'environnement. La durée de l'anthèse est stable et limitée à environ 2 heures par jour, alors que l'heure de l'anthèse varie de 3.4 à 6.75 heure solaire. Au moment de l'anthèse, TD observée varie entre +2 et -9.5°C. TOA et TD sont principalement caractérisés par Tair et VPD (Vapour Pressure Deficit) observés antérieurement (TOA) ou pendant (TD) l'anthèse. De plus, il existe une corrélation significative entre la stérilité (chaud ou froid) observée à maturité et Tp aux stades sensibles. Ces résultats montrent qu'en termes de risque de stérilité paniculaire pour le riz irrigué à floraison, un climat moyennement chaud et humide est plus dangereux qu'un climat très chaud mais sec car un fort VPD favorise la transpiration de la canopée et des panicules. TOA et TD ont ensuite été intégrés au modèle de culture RIDEV V.2 (qui prédit la stérilité) et les simulations de TD ont été comparées aux résultats d'un autre modèle de Tp (IM2PACT) développé indépendamment au Japon. Ces deux modèles s'avèrent robustes, et de futures collaborations mèneront à une validation complète de chaque modèle voire une intégration de ceux-ci à un nouvel outil en vues d'étudier l'impact des changements climatiques sur les cultures.Les résultats de cette étude permettront dans un futur proche 1) d'aider les sélectionneurs en apportant de nouveaux traits d'intérêts, et 2) de définir un zonage des territoires à haut risque de stress thermique pour le riz irrigué, pour des scénarios climatiques actuels et anticipés. Des études complémentaires seront nécessaires pour permettre l'application de cette approche aux systèmes non irrigués
At the reproductive stage, rice spikelets are sensitive to cold and to heat which can lead to spikelet sterility. However, it is not the air temperature but the temperature of the sensitive organ itself during some specific sensitive stages that is involved. There are three different strategies to cope with thermal stress: 1) physiological tolerance of a particular variety; 2) temporal escape of the stress thanks to phenology and time of day of anthesis (TOA) adjustments; 3) stress avoidance through microclimate generated by crop architecture and transpiration. This PhD aims to characterize the effect of environment on 2) and 3) and to attain this goal, the same experiment was conducted with four rice varieties irrigated and grown in four different climatic environments (Philippines, Senegal two seasons, France). Even though few varietal differences were observed within a site, a great variability of TOA and difference of temperature (TD) between panicle (Tp) and air (Tair) exists in response to the environment. Anthesis duration is stable and limited to 2 hours per day, whereas time of onset of anthesis varied between 3.4 to 6.75 hours after sunrise. During anthesis, observed TD varied between +2.5 and -9.5°C. TOA and TD are mostly explained with Tair and VPD (Vapour Pressure Deficit) observed before (TOA) or during (TD) anthesis. A significant correlation between spikelet sterility (due to cold or heat) and Tp at sensitive stages was established across sites and varieties. Those results showed that for irrigated rice, humid and moderately hot environments are more subject to heat stress sterility than very hot but dry environments, because panicle and canopy transpiration are favored by high VPD. Ultimately, RIDEV V.2 crop model (predicting spikelet sterility) was developed to integrate the previous results and Tp simulations were compared to another Tp model (IM2PACT) simulations, developed independently with a different approach in Japan. Those two models are robust and future collaborations will lead to complete model validations and maybe integration in a new modeling tool to answer the need in evaluating the impact of different climate change scenarios and the adaptation of crop response to those changes.In a short term, the results of this study will enable to 1) help breeders providing them new interest traits for thermal tolerance, and 2) define geographic zoning for high heat stress risk for irrigated rice, for present and future climate change scenarios. Complementary studies are needed to apply this approach to non irrigated system
APA, Harvard, Vancouver, ISO, and other styles
6

Lewis-Smith, Stella M. "Experimental studies on the relationship between spikelet primordia and grain size in barley." Thesis, University of Edinburgh, 1991. http://hdl.handle.net/1842/15210.

Full text
Abstract:
This project aimed to examine the relationship between spikelet primordium size at the double ridge stage and the final grain weight in two row barley. Earlier work in this laboratory had suggested that the size of primordia at the double ridge stage influenced final grain size. This work was repeated to confirm the finding and, whilst the relationship held, the results were quantitatively different due to differing environmental conditions during the later stages of grain development. Subsequent work sought to manipulate primordial width at double ridge stage by altering both temperature and nitrogen supply in order to determine the generality of the apparent primordium width/grain weight relationship. Results from these experiments led to investigation of the effect of tillers and the application of a growth retardent on the size of spikelets and grain. Lowered nitrogen supply for the first 40 days after sowing reduced the size of spikelet primordia at the double ridge stage and this resulted in the production of smaller grain. Reduced nitrogen supply for only 20 days after sowing led to reduced grain weight in cv. Maris Mink but not in cv Proctor. Proctor had larger central florets and set larger grain than Maris Mink. Reduced nitrogen supply during the vegetative stage of mainstem apex development had no effect on spikelet size in Proctor but marginally increased spikelet size in Maris Mink. Final grain size was reduced in Proctor but increased in Maris Mink. Lowering the temperature in which plants were grown increased grain size and number but had no effect on spikelet size.
APA, Harvard, Vancouver, ISO, and other styles
7

Berzelius, Jonny, and Anna Pettersson. "Huvudet på spiken! : Kompetensutveckling inom byggsektorn." Thesis, Örebro University, Department of Education, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-306.

Full text
Abstract:

Undersökningen tar avstamp i SOU 2002:115. Här påvisas behovet av kompetensutveckling inom byggsektorn. Ett problem är om aktörerna definierar kompetensutveckling olika vid samarbete i frågan. En teoretisk bakgrund beskriver forskningsområdet. Frågeställningar utifrån syfte och problem är: Hur definierar de olika aktörerna i vår undersökning kompetensutveckling? Vad anser aktörerna vara viktiga aspekter på kompetensutveckling? Hur arbetar man inom byggsektorn med kompetensutveckling? Undersökningen bygger på intervjuer och har en kvalitativ ansatts där förståelse söks. Urvalet, sju respondenter från olika aktörer sker med ändamålsurval. Begränsningar görs geografiskt och storleksmässigt pga. tidsram och ekonomi. Analys görs med hjälp av en modell, Lund & Sundberg (2004), för en djupare förståelse av sammanhang och skillnader. Resultat och diskussion visar skillnader och likheter i de olika aktörernas uppfattning av kompetensutveckling. En bild av hur det arbetas med kompetensutveckling inom det begränsade området för vår undersökning ges. Diskussionen ger även förslag på vidare forskning.

APA, Harvard, Vancouver, ISO, and other styles
8

Gunawardena, Thusitha A. "Spikelet sterility in rice (oryza sativa L.) induced by low termperature and nitrogen fertilisation /." St. Lucia, Qld, 2001. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe16554.pdf.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Michalikova, Martina [Verfasser], Richard [Gutachter] Kempter, Romain [Gutachter] Brette, and James [Gutachter] Poulet. "Mechanisms of spikelet generation in cortical pyramidal neurons / Martina Michalikova ; Gutachter: Richard Kempter, Romain Brette, James Poulet." Berlin : Lebenswissenschaftliche Fakultät, 2017. http://d-nb.info/1130698548/34.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Tsakirpaloglou, Nikolaos K. "Identification & characterization of a rice spikelet-specific germin like protein : is superoxide dismutase activity its only role?" Thesis, University of Newcastle upon Tyne, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.607162.

Full text
Abstract:
Reactive oxygen species (ROS) such as superoxide, peroxide, hydroxyl ion and singlet oxygen radical are by-products of specific metabolic reactions in plants. ROS damage cellular biomolecules and are thus actively scavenged. However, ROS also act as signal transducers during development and stress responses. Redox enzymes such as superoxide dismutase (SOD) contribute to achieving a balance between ROS being scavenged and being available as signal transducers. Spatio-temporally differential expression of SODs in various tissues plays a critical role in scavenging the superoxide radical. Using a nitroblue-tetrazolium-riboflavin-based in-gel SOD assay, up-regulation of two low mobility (~96 kDa and ~92 kDa) putative SODs was observed in rice spikelets. The two proteins were purified by gel electrophoresis and both were identified through mass spectrometry as homotetrameric versions of a single germin-like protein (GLP), encoded by the gene LaC _Os08g08960 (Rice Genome Annotation Project). Staining with a glycoprotein gel stain and enzymatic deglycosylation showed that the protein is post-translationally modified by N-glycosylation; differential modification probably accounts for_the difference between the two forms. Biochemical characterization- of this developmentally regulated spikelet-specific GLP (ssGLP) indicated that its SOD activity is Mn-SOD type and is highly stable in denaturing agents and at elevated temperatures. Tetrameric ssGLP lacks oxalate oxidase activity. The biological functions of GLPs have not been fully defined; among the different functions attributed to them their role in biotic stress tolerance is relatively well studied. Rice germins, especially some of those with genes on chromosome 8 in the same cluster as the LaC _Os08g08960 gene, although not this specific gene, have previously been found to contribute to the basal mechanism of resistance to pathogens causing rice blast and sheath blight disease. ssGLP was estimated to contribute nearly 11% of the total SOD activity in rice spikelets, indicating a crucial developmental role. Expression analysis with the in-gel SOD assay at the spatio-temporal level, as well as treatment with various hormones, chemicals and abiotic variables such as wounding and light indicated that the expression of ssGLP is affected by developmental rather than stress stimuli. Further, expression analysis at the spatio-temporallevel through RT-PCR confirmed the developmental patterns observed previously at the protein level. In situ mRNA hybridization studies provided evidence for ssGLP gene expression in pollen and endosperm and in localized regions of leaves, and for production of antisense RNA. Consistent with the up-regulation in spikelets, in silico comparison of the rice GLP promoters revealed more seed and pollen specific motifs in LOC_Os08g08960 than in other GLP genes. Additionally, presence of a GAF protein domain typical of cyclic nucleotide phosphodiesterases is unique to ssGLP. Preliminary enzyme assays and in silico results suggested that ssGLP may act as a nucleotide-sugar pyrophosphatase/phosphodiesterase (NSPPase) similarly to a previously-described barley GLP. As a first step to a fuller definition of the enzyme activity of ssGLP and in particular to testing the hypothesis that a different oligomeric configuration acts as NSPPase, a gene for recombinant ssGLP was constructed, cloned and expressed in Pichia pastoris.
APA, Harvard, Vancouver, ISO, and other styles
More sources

Books on the topic "Spikenet"

1

Terrell, Edward E. Epidermal features and spikelet micromorphology in Oryza and related genera (Poaceae:Oryzeae). Washington, D.C: Smithsonian Institution Press, 2001.

Find full text
APA, Harvard, Vancouver, ISO, and other styles

Book chapters on the topic "Spikenet"

1

Lynch, Kristina A., Roger L. Arnoldy, and Paul M. Kintner. "Observations of lower-hybrid spikelet phenomena: Topaz3 particle data." In Cross‐Scale Coupling in Space Plasmas, 111–20. Washington, D. C.: American Geophysical Union, 1995. http://dx.doi.org/10.1029/gm093p0111.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Nishiyama, I., and T. Morikawa. "Differential of Spikelet Type in Avena in Relation to the Ploidy." In Proceedings of the Second International Oats Conference, 48–49. Dordrecht: Springer Netherlands, 1986. http://dx.doi.org/10.1007/978-94-009-4408-4_10.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Maes, B., R. M. Trethowan, M. P. Reynolds, M. Van Ginkel, and B. Skovmand. "Glume Pubescence and Its Influence on Spikelet Temperature of Wheat under Freezing Conditions." In Wheat in a Global Environment, 463–70. Dordrecht: Springer Netherlands, 2001. http://dx.doi.org/10.1007/978-94-017-3674-9_61.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Alkhudaydi, Tahani, Ji Zhou, and Beatriz De La lglesia. "SpikeletFCN: Counting Spikelets from Infield Wheat Crop Images Using Fully Convolutional Networks." In Artificial Intelligence and Soft Computing, 3–13. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-20912-4_1.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Shimono, Hiroyuki, Toshihiro Hasegawa, Hiroki Asaishi, Tsutomu Nishimura, Masahito Mikami, Yutaka Jitsuyama, and Kazuto Iwama. "Effects of root pruning and root zone restriction on spikelet fertility of paddy rice (Oryza sativa L.) under cool water condition." In Roots: The Dynamic Interface between Plants and the Earth, 455–60. Dordrecht: Springer Netherlands, 2003. http://dx.doi.org/10.1007/978-94-017-2923-9_45.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Fornaciari, Rita, Laura Arru, Rita Terenziani, and Anna Maria Mercuri. "The Role of Morphometry to Delineate Changes in the Spikelet Shape of Wild Cereals: The Case Study of Takarkori (Holocene, Central Sahara, SW Libya)." In Plants and People in the African Past, 100–122. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-89839-1_7.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Iwasaki, Yasunaga, Tadahiko Mae, Chikafusa Fukazawa, Amane Makino, Koji Ohira, and Kunihiko Ojima. "Glutelin accumulation and changes in the levels of its mRNA in the superior and inferior spikelets of rice ear during ripening." In Plant Nutrition — from Genetic Engineering to Field Practice, 231–34. Dordrecht: Springer Netherlands, 1993. http://dx.doi.org/10.1007/978-94-011-1880-4_44.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

"Spikelet." In Encyclopedia of Genetics, Genomics, Proteomics and Informatics, 1857. Dordrecht: Springer Netherlands, 2008. http://dx.doi.org/10.1007/978-1-4020-6754-9_15977.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

"Spiken." In Springer Reference Medizin, 2195. Berlin, Heidelberg: Springer Berlin Heidelberg, 2019. http://dx.doi.org/10.1007/978-3-662-48986-4_313509.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

"Young spikelet and mature spikelet . g. Caryopsis. Drawn by Priscilla Fawcett. From Correll and Correll 1982." In Florida Ethnobotany, 672. CRC Press, 2004. http://dx.doi.org/10.1201/9780203491881-85.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "Spikenet"

1

Padilla, Maria Victoria C., Nilo M. Arago, John Carlos M. Damgo, Gener D. Junio, John Jeric R. Mamaril, Ronalyn N. Matienzo, and Gessel S. Natabio. "Rice Spikelet Yield Determination Using Image Processing." In 2018 IEEE 10th International Conference on Humanoid, Nanotechnology, Information Technology,Communication and Control, Environment and Management (HNICEM). IEEE, 2018. http://dx.doi.org/10.1109/hnicem.2018.8666312.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Kirkland, Paul, Gaetano Di Caterina, John Soraghan, and George Matich. "SpikeSEG: Spiking Segmentation via STDP Saliency Mapping." In 2020 International Joint Conference on Neural Networks (IJCNN). IEEE, 2020. http://dx.doi.org/10.1109/ijcnn48605.2020.9207075.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Shanmugaraj, Nandhakumar. "Studying apical spikelet abortion in barley inflorescence by spatiotemporal profiling of hormones and primary metabolome." In ASPB PLANT BIOLOGY 2020. USA: ASPB, 2020. http://dx.doi.org/10.46678/pb.20.1332354.

Full text
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the extended bibliographies on the topic 'Spikenet' for particular source types:
Journal articles Dissertations / Theses
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography