Relevant bibliographies by topics / Nectar

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Academic literature on the topic 'Nectar'

Author: Grafiati
Published: 4 June 2021
Last updated: 20 February 2023

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Journal articles on the topic "Nectar"

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Chatt, Elizabeth C., Siti-Nabilla Mahalim, Nur-Aziatull Mohd-Fadzil, Rahul Roy, Peter M. Klinkenberg, Harry T. Horner, Marshall Hampton, Clay J. Carter, and Basil J. Nikolau. "Nectar biosynthesis is conserved among floral and extrafloral nectaries." Plant Physiology 185, no. 4 (January 28, 2021): 1595–616. http://dx.doi.org/10.1093/plphys/kiab018.

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Abstract Nectar is a primary reward mediating plant–animal mutualisms to improve plant fitness and reproductive success. Four distinct trichomatic nectaries develop in cotton (Gossypium hirsutum), one floral and three extrafloral, and the nectars they secrete serve different purposes. Floral nectar attracts bees for promoting pollination, while extrafloral nectar attracts predatory insects as a means of indirect protection from herbivores. Cotton therefore provides an ideal system for contrasting mechanisms of nectar production and nectar composition between different nectary types. Here, we report the transcriptome and ultrastructure of the four cotton nectary types throughout development and compare these with the metabolomes of secreted nectars. Integration of these datasets supports specialization among nectary types to fulfill their ecological niche, while conserving parallel coordination of the merocrine-based and eccrine-based models of nectar biosynthesis. Nectary ultrastructures indicate an abundance of rough endoplasmic reticulum positioned parallel to the cell walls and a profusion of vesicles fusing to the plasma membranes, supporting the merocrine model of nectar biosynthesis. The eccrine-based model of nectar biosynthesis is supported by global transcriptomics data, which indicate a progression from starch biosynthesis to starch degradation and sucrose biosynthesis and secretion. Moreover, our nectary global transcriptomics data provide evidence for novel metabolic processes supporting de novo biosynthesis of amino acids secreted in trace quantities in nectars. Collectively, these data demonstrate the conservation of nectar-producing models among trichomatic and extrafloral nectaries.
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Silva, Fredy A., Elizabeth C. Chatt, Siti-Nabilla Mahalim, Adel Guirgis, Xingche Guo, Daniel S. Nettleton, Basil J. Nikolau, and Robert W. Thornburg. "Metabolomic Profiling of Nicotiana Spp. Nectars Indicate That Pollinator Feeding Preference Is a Stronger Determinant Than Plant Phylogenetics in Shaping Nectar Diversity." Metabolites 10, no. 5 (May 22, 2020): 214. http://dx.doi.org/10.3390/metabo10050214.

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Floral nectar is a rich secretion produced by the nectary gland and is offered as reward to attract pollinators leading to improved seed set. Nectars are composed of a complex mixture of sugars, amino acids, proteins, vitamins, lipids, organic and inorganic acids. This composition is influenced by several factors, including floral morphology, mechanism of nectar secretion, time of flowering, and visitation by pollinators. The objective of this study was to determine the contributions of flowering time, plant phylogeny, and pollinator selection on nectar composition in Nicotiana. The main classes of nectar metabolites (sugars and amino acids) were quantified using gas chromatography/mass spectrometric analytical platforms to identify differences among fifteen Nicotiana species representing day- and night-flowering plants from ten sections of the genus that are visited by five different primary pollinators. The nectar metabolomes of different Nicotiana species can predict the feeding preferences of the target pollinator(s) of each species, and the nectar sugars (i.e., glucose, fructose, and sucrose) are a distinguishing feature of Nicotiana species phylogeny. Moreover, comparative statistical analysis indicate that pollinators are a stronger determinant of nectar composition than plant phylogeny.
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Zambon, Vivian, Kayna Agostini, Massimo Nepi, Mônica Lanzoni Rossi, Adriana Pinheiro Martinelli, and Marlies Sazima. "The role of nectar traits and nectary morphoanatomy in the plant-pollinator interaction between Billbergia distachia (Bromeliaceae) and the hermit Phaethornis eurynome (Trochilidae)." Botanical Journal of the Linnean Society 192, no. 4 (December 9, 2019): 816–27. http://dx.doi.org/10.1093/botlinnean/boz107.

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Abstract Nectar production dynamics can show inter- and intraspecific variation, which can be associated with environmental and ecological factors and with the ultrastructural diversity of the floral nectary. In this context, we recorded nectar production dynamics from a morphofunctional perspective using the hummingbird-pollinated Billbergia distachia (Bromeliaceae). The scale-throated hermit Phaethornis eurynome was the only floral visitor observed, indicating a specialized pollination system. Nectar production showed significant differences between day and night, and the periods of major pollinator activity and nectar secretion were synchronous. The ultrastructural features of the nectary showed some evidence of nectar reabsorption in flowers at night, and it can be inferred that this process may be a key factor in the nocturnal pause in nectar production. In this way, nectary morphoanatomy, nectar traits and an energy-saving mechanism through nectar reabsorption contribute to the well-established relationship between B. distachia and P. eurynome.
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Stolar, Jessica, and Arthur R. Davis. "Floral nectary structure, nectar production, and carbohydrate composition in theLiliumAsiatic hybrid ‘Trésor’." Botany 88, no. 2 (February 2010): 185–205. http://dx.doi.org/10.1139/b09-109.

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Floral nectary structure, nectar production, and carbohydrate composition were compared from petals (“inner tepals”) and sepals (“outer tepals”) of Lilium Asiatic hybrid ‘Trésor’ (Liliaceae). The six nectaries each occupied a narrow furrow bordered by two convergent ridges extending adaxially from the petal and sepal base. Each sepal nectary furrow was shorter and more concealed. In both nectary types, many vascular bundles comprising xylem and phloem supplied 5.5–8 layers of nectariferous parenchyma cells below the epidermis, which lacked stomata. Transmission electron microscopy of sepal nectaries demonstrated that parts of the outer epidermal wall adhered to an intact but uplifted cuticle in nectar-secreting flowers. Both apoplastic and symplastic routes were continuous from the vascular bundles to the nectary epidermis. Starch breakdown from amyloplasts throughout the nectary likely augmented nectar production. Nectar solute concentration from another Asiatic hybrid, ‘Orange Pixie’, was also significantly higher in petals. In ‘Trésor’, significantly more nectar was available from sepals, possibly reflecting reduced evaporation from multiple nectar droplets within the covered nectary furrow. However, for both hybrids, the same quantity of nectar sugar was produced by petals and sepals. Nectar composition from petals and sepals also was alike, in ‘Orange Pixie’ averaging 67/19/14 (= sucrose/fructose/glucose) and 59/25/17, respectively, and in ‘Trésor’ averaging 68/23/10 and 62/27/12, respectively.
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Chwil, Mirosława, and Elżbieta Weryszko-Chmielewska. "Nectary structure and nectar secretion of Echium russicum J. F. Gmel. flowers." Acta Agrobotanica 60, no. 1 (2012): 25–33. http://dx.doi.org/10.5586/aa.2007.003.

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In this study, the micromorphology of nectaries in <i>Echium russicum</i> J. F. Gmel. flowers was determined by using scanning electron microscopy (SEM) and their anatomy by using light microscopy (LM). The rate of nectar production of flowers and sugar concentration in nectar were investigated. The nectary gland is located below the ovary of the pistil. It is composed of 4 parts corresponding to the parts of the ovary. The widest regions of the nectar-producing tissue are situated by the furrows separating the adjacent parts of the ovary. Nectar is secreted through anomocytic stomata, located only in the lower part of the nectary. The stomata were distributed evenly or they formed clusters of 2-3. The average number of stomata on the surface of the whole nectary was 184. At the nectar secretion stage, open and closed, as well as not fully mature stomata were observed. The orientation of most of the stomata was parallel to the nectary base. The cuticle surface of the cells of the upper and lateral part of the nectary was smooth, whereas in the region producing stomata it showed various folds facilitating the retention of nectar. The flowers produced nectar throughout the flowering period. The weight of nectar secreted throughout the lifetime of ten flowers was, on the average, 20 mg, with the concentration of sugars of 58% and their weight reaching 17 mg.
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Al-Tardeh, Sharaf, Thomas Sawidis, Barbara-Evelin Diannelidis, and Stylianos Delivopoulos. "Nectary structure and nectar presentation in the Mediterranean geophyte, Urginea maritima (Hyacinthaceae)." Botany 86, no. 10 (October 2008): 1194–204. http://dx.doi.org/10.1139/b08-075.

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The morphology, anatomy, and ultrastructure of the floral nectary of Urginea maritima (L.) Baker were investigated at three stages of nectary development. The plant possesses a typical gynopleural (septal) nectary with secondary presentation. The nectary consists of one layer of epithelium secretory cells and one to four layers of subsidiary cells subtended by two to six layers of parenchyma (subnectary) cells. The nectary releases the nectar at a point two-thirds towards the summit of the ovary by means of carpellary sutures. Nectar secretion appears to depend largely on the hydrolysis of starch grains stored in amyloplasts at the intermediate stage. The hydrolysis process most likely commences in the epithelium layer followed by the subsidiary tissue and then the parenchyma cells of the ovary wall. A symplastic transfer of the secreted nectar occurs by plasmodesmata connecting the subsidiary cells to the parenchyma and the epithelial secretory cells. However, microchannels in the cell wall of the epithelial cells may facilitate the apoplastic transfer of the nectar into the nectary cavity. The old stage of nectary development is characterized by a crystallized form of nectar, collapse of the parenchyma cells, complete starch hydrolysis, and disappearance of the amyloplasts and endoplasmic reticulum.
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Weryszko-Chmielewska, Elżbieta, and Mirosława Chwil. "Structure of floral nectaries in Aesculus hippocastanum L." Acta Botanica Croatica 76, no. 1 (March 1, 2017): 41–48. http://dx.doi.org/10.1515/botcro-2016-0049.

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Abstract Representatives of the family Sapindaceae exhibit high morphological diversity of the nectary structure. The present paper shows for the first time the results of micromorphological, anatomical, and ultrastructural analyses of floral nectaries in Aesculus hippocastanum. We have also described the forage and signal attractants of these flowers, which are important for the ecology of pollination. Using light, fluorescence, and electron microscopy, we demonstrated that the A. hippocastanum nectary forming a lobed disc is histologically differentiated into the epidermis with stomata, nectariferous parenchyma, subglandular parenchyma, and vascular bundles reaching the basal part of the nectariferous parenchyma. The use of histochemical assays revealed the presence of insoluble polysaccharides, lipids, terpenoids, and polyphenols including coumarins in the nectary tissues. Nectar is exuded onto the nectary surface via stomata and the permeable cuticle. As indicated by the observation of the ultrastructure of the nectary cells, transport of pre-nectar into parenchymal cells may proceed via the symplast and apoplast. We have also demonstrated that nectar transfer outside the protoplasts of parenchymal cells has a character of granulocrine secretion. A. hippocastanum flowers produce nectar abundantly; one flower secreted on average 2.64 mg of nectar and the concentration of sugars in the nectar was 33%.
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Amato, Bianca, Sophie Petit, and Russell Schumann. "Improving floral nectar storage on filter paper for sugar recovery." Australian Journal of Botany 69, no. 8 (2021): 585. http://dx.doi.org/10.1071/bt21006.

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Nectar analysis has been used to understand pollination systems, but nectar storage methods have rarely been considered as potential sources of inaccuracy in the recovery of data. Prompt nectar sugar analysis is not always possible and storage methods can affect results. We aimed to develop an effective method to store nectar on filter paper. Nectars from two subspecies of Eremophila maculata (Scrophulariaceae) and Strelitzia reginae (Strelitziaceae) were spotted on filter papers. Nectars were redissolved and assayed by high-performance liquid chromatography to determine the masses of sugars recovered from the papers from Day 0 to Day 30. We evaluated the effects of the method of elution, paper type and size, and storage treatments on sugar recovery. Liquid nectars were also stored in the refrigerator. Sugars were best eluted from filter papers in 15mL of water and agitated for 1min. Nectar sugars stored on small papers tended to be recovered more successfully than those stored on larger papers (significantly for glucose). Paper performed better than nylon for glucose. Desiccant had a marginal positive effect on nectar sugar recovery, and filter paper performed better than did refrigeration of liquid nectar for storage. If highly accurate measurements are needed, nectars should be eluted with large volumes of water from small filter papers stored with desiccant within a few days of collection.
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Davis, A. R., R. W. Shuel, and R. L. Peterson. "Distribution of carbofuran and dimethoate in flowers and their secretion in nectar as related to nectary vascular supply." Canadian Journal of Botany 66, no. 7 (July 1, 1988): 1248–55. http://dx.doi.org/10.1139/b88-178.

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The distribution of two systemic insecticides (carbofuran, dimethoate) in floral parts and nectar of Ajuga reptans L. (Lamiaceae), Brassica napus L. (Brassicaceae), and Vicia faba L. (Leguminosae), which differ in their types of nectary vascular supply, was determined. Radioactivity was detected in all floral organs when excised flowering plant tops were cultured in sucrose solution containing a combination of 14C-labelled and formulated (unlabelled) insecticide. In A. reptans and B. napus, combined nectary tissue and nectar contained the most radioactivity on a fresh weight basis. Radioactivity was detected in floral nectar of all species, and in extrafloral nectar of V. faba. Estimated concentrations of insecticide were much higher in extrafloral than in floral nectar of V. faba; the presence of xylem in the nectary vasculature to the former may be responsible. However, the presence of xylem is not necessary for the secretion of systemic insecticides by nectaries.
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Bory, Gérarad, and Danielle Clair-Maczulajtys. "Composition du nectar et rôle des nectaires extrafloraux chez l'Ailanthus glandulosa." Canadian Journal of Botany 64, no. 1 (January 1, 1986): 247–53. http://dx.doi.org/10.1139/b86-036.

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The composition of the extrafloral nectar from Ailanthus glandulosa varies according to the type of nectary. When the buds open, those which are located on the cataphylls or the stipules are only supplied by carbohydrate reserves. In this case, a high sucrose content is found in the nectar, and rhamnose is also detected. The floriferous or sterile state of the trees does not modify the sugar composition of the foliar nectar. For amino acids, the predominance of serine, threonine, and proline is constant in all types of nectars. The amount of proline is very important in the nectar of the cataphylls and increases with the age of the leaf. The activity of the foliar nectaries seems to correlate with the occurrence of a requirement for photosynthetic products. The nectaries from trees developing fruits or from those showing only vegetative growth continue to be functional for a long time. The ablation of foliar nectaries leads to a sugar accumulation in the leaf and slows down the reconstitution of starch reserves in the branch. The function of the extrafloral nectaries is interpreted as being the elimination of excess sugars. Thus, the initiation of these nectaries may be due to a carbohydrate accumulation during the ontogeny of foliar organs.
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Dissertations / Theses on the topic "Nectar"

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Arnold, Paige Marie. "Variation in nectar composition: The influence of nectar quality on Monarch success." Bowling Green State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1467568732.

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Burquez-Montijo, Jose Alberto. "Studies on nectar secretion." Thesis, University of Cambridge, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.235811.

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This thesis explores the dynamic patterns in the secretion, reabsorption and concentration of nectar, and their relation with microclimate, flower visitors and the innervation of the nectaries. Case studies are presented, comprising Impatiens glandulifera, Brassica napus, Fritillaria imperialis and Borago officinalis. Nectar secretion rate and nectar solute concentration are affected by the environment, and probably by the genetic composition of the plants. Significant differences in nectar secretion rate and nectar concentration are found between plants, between times of the day and between days, but not among flowers on the same plant. Correlation matrices and correlograms help us to disentangle multiple interactions. In all the species studied, the environmental factor most likely to affect nectar secretion rate seems to be the temperature of the air. Other factors also contribute to explain the variation in nectar secretion rate, among them the stand age (probably acting through the relative sink strength of the flowers), and the number of flowers and fruits per module. The supply of assimilates to the nectary is explored by experimental defoliations and deprivation of light. In both cases an immediate response is elicited, but the degree of response varies between species. Brassica napus, for example, is much less sensitive to light deprivation or total defoliation than Fritillaria imperialis. Nectar solute concentration seems to depend mainly on the relative humidity of the air. However, some evidence suggests that plant water status might affect nectar concentration. These results, obtained from field experiments, were confirmed in controlled conditions in growth chambers. Other minor factors probably play a role, but their effects are obscured by complex physiological interactions. We conclude that in a given plant the nectar secretion rate will depend mainly on its physiological age, and on variations in air temperature, while the nectar solute concentration at a given moment will be mainly the product of the short-term plant-microclimate interaction. In this context, constraints on the evolution of nectar presentation systems are considered.
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Taylor, Robin M. "Plant nectar contributes to the survival, activity, growth, and fecundity of the nectar-feeding wandering spider Cheiracanthium inclusum (Hentz) (Miturgidae)." Columbus, Ohio : Ohio State University, 2004. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1086114717.

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Thesis (Ph. D.)--Ohio State University, 2004.
Title from first page of PDF file. Document formatted into pages; contains xii, 138 p.; also includes graphics. Includes abstract and vita. Advisor: Richard A. Bradley, Dept. of Evolution, Ecology, and Organismal Biology. Includes bibliographical references (p. 124-138).
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Richardson, Sarah Claire. "The effects of nectar-robbing on a plant-pollinator mutualism and the evolution of nectar-robbing and sociality in bees." Diss., The University of Arizona, 2001. http://hdl.handle.net/10150/290257.

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How will the intrusion of other species that remove rewards without providing reciprocal services affect the interaction between mutualists? How do costs and benefits from these "cheaters" compare to costs and benefits from potentially mutualistic visitors? Finally, did nectar-robbing, one kind of cheating, promote the evolution of complex levels of sociality by allowing bees access to a wider range of resources? I investigated these questions in the research described below. I found that pollinators visiting Chilopsis linearis (Bignoniaceae) spent less time visiting robbed flowers than visiting unrobbed flowers, and did not visit them as often as expected. Thus, robbing appeared to have a negative effect on pollinators visiting Chilopsis linearis . I compared costs and benefits of floral visitors to Chilopsis linearis (desert willow). Chilopsis had sensitive stigmas that closed immediately upon touch and may have reopened later. I found that the probability of stigma reopening depended on the source and number of pollen grains deposited. I compared visitors by number of pollen grains deposited, viability of pollen that they deposited, and their effect on stigmas. Nectar-robbers did not benefit plants by pollen deposition, but they also did not cost plants by causing stigmas to close without adequate pollen having been deposited. I investigated the effects of robbing on pollinator behavior and plant reproductive success. Nectar volumes were lower in robbed flowers than in unrobbed flowers. However, the most effective pollinators, bumblebees, did not avoid robbed flowers. In investigating male reproductive success, I found that on some days, dye mimicking pollen traveled farther from robbed flowers, indicating that robbing may sometimes be beneficial to plants. In investigating female reproductive success, I found that there was no difference in pollen tube number between robbed and unrobbed flowers. Thus, a negative effect on one mutualist may not affect the other mutualist. I hypothesized that the evolution of robbing in bees was associated with a broad diet breadth and the evolution of complex sociality. Using phylogenetically independent contrasts for taxa within three geographical regions, I found that in some cases, a broad diet breadth was associated with sociality and robbing.
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Williams, Catherine Sian. "Foraging ecology of nectar-collecting bumblebees and honeybees." Thesis, University of Cambridge, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245189.

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Waser, Nickolas M., and Mary V. Price. "Drought, pollen and nectar availability, and pollination success." WILEY-BLACKWELL, 2016. http://hdl.handle.net/10150/616997.

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Pollination success of animal-pollinated flowers depends on rate of pollinator visits and on pollen deposition per visit, both of which should vary with the pollen and nectar "neighborhoods" of a plant, i.e., with pollen and nectar availability in nearby plants. One determinant of these neighborhoods is per-flower production of pollen and nectar, which is likely to respond to environmental influences. In this study, we explored environmental effects on pollen and nectar production and on pollination success in order to follow up a surprising result from a previous study: flowers of Ipomopsis aggregata received less pollen in years of high visitation by their hummingbird pollinators. A new analysis of the earlier data indicated that high bird visitation corresponded to drought years. We hypothesized that drought might contribute to the enigmatic prior result if it decreases both nectar and pollen production: in dry years, low nectar availability could cause hummingbirds to visit flowers at a higher rate, and low pollen availability could cause them to deposit less pollen per visit. A greenhouse experiment demonstrated that drought does reduce both pollen and nectar production by I. aggregata flowers. This result was corroborated across 6 yr of variable precipitation and soil moisture in four unmanipulated field populations. In addition, experimental removal of pollen from flowers reduced the pollen received by nearby flowers. We conclude that there is much to learn about how abiotic and biotic environmental drivers jointly affect pollen and nectar production and availability, and how this contributes to pollen and nectar neighborhoods and thus influences pollination success.
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Day, Meigan. "Nectar Resource Quality of Oak Savanna Pollinator Habitats." Bowling Green State University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1587770638706345.

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Kaczorowski, Rainee L. "Nectar in Nicotiana : pollinator associations, sources of variation, and evolutionary consequences /." Diss., Columbia, Mo. : University of Missouri-Columbia, 2007. http://hdl.handle.net/10355/4813.

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Thesis (Ph. D.)--University of Missouri-Columbia, 2007.
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on September 25, 2007) Vita. Includes bibliographical references.
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Wintergerst, Sabine. "Modulators of foraging behavior by nectar-feeding bats (Glossophaginae)." Doctoral thesis, Humboldt-Universität zu Berlin, 2018. http://dx.doi.org/10.18452/18673.

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Zahlreiche Forschungsarbeiten haben gezeigt, dass nicht nur Menschen, sondern auch Tiere konstante individuelle Unterschiede im Verhalten aufweisen. Zu verstehen warum sich diese Verhaltensunterschiede im Laufe der Evolution entwickelt haben, ist ein Ziel dieses Forschungsbereiches. In dieser Arbeit wurde untersucht wie verschiedene Modulatoren das Nahrungssuchverhalten von Blütenfledermäusen (Glossophaginae) beeinflussen um individuelle Verhaltensunterschiede zu quantifizieren und theoretische Vorhersagen zu testen. Alle Experimente wurden in naturnaher Umgebung mit programmierbaren, künstlichen Blüten durchgeführt. Es wird angenommen, dass die Plastizität von Verhalten ein generelles Merkmal ist in dem sich Tiere unterscheiden, da manche Individuen allgemein stärker auf Reize aus der Umwelt reagieren könnten als andere. Um diese Vorhersage zu testen, wurde die Nahrungsverfügbarkeit experimentell manipuliert und zwei Arten von Verhaltensplastizität in denselben Individuen gemessen. Die Ergebnisse unterstützen diese Annahme jedoch nicht, da die beiden Arten von Verhaltensplastizität nicht korrelieren. Neben Umwelteinflüssen können auch innere Merkmale wie die Stoffwechselrate das individuelle Nahrungssuchverhalten beeinflussen. Die Ergebnisse zeigen, dass sich die Individuen in ihrem täglichen Energieverbrauch unterscheiden und dass diese Unterschiede mit dem Explorationsverhalten während der Nahrungssuche korrelieren. Zusätzlich kann das individuelle Nahrungssuchverhalten auch von sozialen Faktoren beeinflusst werden. Bei limitierter Nahrungsverfügbarkeit verteidigen einzelne Männchen Blüten gegen andere Männchen, jedoch nicht gegenüber Weibchen. Individuelle Unterschiede in der Aggression und Aktivität werden dagegen nicht von der sozialen Gruppenzusammensetzung beeinflusst. In dieser Arbeit wurden nicht nur individuelle Unterschiede im Nahrungssuchverhalten von Blütenfledermäusen bestimmt, sondern auch Vorhersagen aus dem Bereich der Persönlichkeitsforschung bei Tieren überprüft.
Animal personality research has shown that animals express individual differences in their behavior that are consistent over time and/or across situations. Furthermore, animal personality research aims to understand how these individual differences in behavior evolve and how they are maintained within populations. This thesis focuses on how different modulators influence the foraging behavior of nectar-feeding bats (Glossophaginae) in order to investigate consistent individual differences in their behavior and to test predictions proposed in the field of animal personality. All experiments were conducted in a semi-natural environment by using a setup of computer-controlled artificial flowers. One prediction of animal personality research is that behavioral plasticity is a single trait in which individuals differ because some individuals might be generally more responsive to changes in the environment than others. In order to test this prediction, resource availability was manipulated and two types of behavioral plasticity were quantified within the same individual. However, the two types of plasticity did not correlate and therefore this hypothesis was not supported. Individual foraging behavior can not only be modulated by changes in the environment but also by individual differences in internal traits like metabolic rates. Experiments confirmed that individual differences in daily energy expenditure correlated with consistent individual differences in exploration. Additionally, foraging behavior can also be modulated by social factors. When resources are limited some males started to defend flowers against other males but not against females. Furthermore, it could be shown that individual differences in aggression and activity are internally driven and not influenced by changes in the social group composition. This thesis not only assessed individual differences in the foraging behavior of nectar-feeding bats but also investigated predictions proposed in the field of animal personality research.
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Jones, Ian M. "The Ecology of Extrafloral Nectar in Senna mexicana var. chapmanii." FIU Digital Commons, 2016. http://digitalcommons.fiu.edu/etd/2594.

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Extrafloral nectar (EFN) mediates food-for-protection mutualisms between plants and defensive insects. Senna mexicana var. chapmanii is a perennial legume native to the pine rockland habitats of south Florida. My dissertation focuses on how anthropogenic changes to the pine rocklands might affect EFN production by S. chapmanii, and the outcome of EFN mediated interactions. First, I investigated the influence of time of day, leaf damage, and leaf age on EFN production in S. chapmanii. Plants produced more nectar at night than during the day, and leaf damage resulted in increased EFN production. Furthermore, the response to leaf damage was greater when plants were damaged in the morning than when plants were damaged at night. Damage to young leaves elicited a stronger defensive response than damage to older leaves, in line with optimal defense theory. Second, I conducted a field experiment to determine the effects of ant activity, and light intensity, on herbivory rates, growth, and reproductive fitness in S. chapmanii. In shaded habitats, the presence of ants had no effect on herbivory rates, seed set, or plant size. In sunny habitats, however, plants with ants suffered less herbivore damage, produced more seeds, and grew larger over the duration of the one year study. Third, through a controlled greenhouse experiment I examined the effects of light intensity, and red/far-red light ratios, on EFN production in S. chapmanii. Plants in light-limited conditions produced less EFN, and leaf damage elicited increased EFN production regardless of light conditions. Ratios of red/far-red light, however, did not affect EFN production in either damaged or undamaged plants. Finally, I conducted a field study to determine how ants affect reproductive fitness in S. chapmanii. Over a period of eight months I observed the effects of ants on the activity of herbivores, predators, pollinators, and pre-dispersal seed predators. Relative pollinator efficiency, and rates of pre-dispersal seed predation, were unaffected by ants. Plants with ants, however, were quicker to establish, grew larger, and produced floral displays that attracted more pollinators. In S. chapmanii ants affected plant reproductive fitness simply by facilitating growth and establishment, with coincidental effects on reproductive investment.
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Books on the topic "Nectar"

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Nectar. New York: Forge, 2002.

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Nectar. Waterville, Me: Thorndike Press, 2003.

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Prior, Lily. Nectar. New York: HarperCollins, 2007.

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Prior, Lily. Nectar. New York: Ecco, 2002.

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చలం, గుడిపాటి వెంకట. Sudha =: Nectar. Delhi: Motilal Banarsidass, 1990.

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Bodunde, Charles. Nectar-pots. Ibadan: Heinemann Educational Books (Nigeria), 1998.

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Rozo, Thierry. Nectar d'abricot: Roman. Paris: Presses de la Renaissance, 1992.

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Nectar dʼAfrique: Poèmes. Abidjan [Ivory Coast]: Nouvelles Editions africaines, 1985.

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Nectar comme Nicolas. Paris: Herscher, 1986.

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Nicolson, Susan W., Massimo Nepi, and Ettore Pacini, eds. Nectaries and Nectar. Dordrecht: Springer Netherlands, 2007. http://dx.doi.org/10.1007/978-1-4020-5937-7.

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Book chapters on the topic "Nectar"

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Nicolson, Sue. "Nectar." In Encyclopedia of Social Insects, 616–19. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-28102-1_82.

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Nicolson, Sue. "Nectar." In Encyclopedia of Social Insects, 1–4. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-319-90306-4_82-1.

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Capinera, John L., Marjorie A. Hoy, Paul W. Paré, Mohamed A. Farag, John T. Trumble, Murray B. Isman, Byron J. Adams, et al. "Nectar Guide." In Encyclopedia of Entomology, 2574. Dordrecht: Springer Netherlands, 2008. http://dx.doi.org/10.1007/978-1-4020-6359-6_2160.

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Nicolson, Susan W., and Robert W. Thornburg. "Nectar chemistry." In Nectaries and Nectar, 215–64. Dordrecht: Springer Netherlands, 2007. http://dx.doi.org/10.1007/978-1-4020-5937-7_5.

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Nicolson, Susan W. "Nectar consumers." In Nectaries and Nectar, 289–342. Dordrecht: Springer Netherlands, 2007. http://dx.doi.org/10.1007/978-1-4020-5937-7_7.

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Hepburn, H. R. "The Nectar Flow." In Honeybees and Wax, 128–38. Berlin, Heidelberg: Springer Berlin Heidelberg, 1986. http://dx.doi.org/10.1007/978-3-642-71458-0_11.

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Archer, W. G. "Ocean of Nectar." In Love Songs of Vidyāpati, 124. London: Routledge, 2021. http://dx.doi.org/10.4324/9781003104216-86.

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Pacini, Ettore, and Susan W. Nicolson. "Introduction." In Nectaries and Nectar, 1–18. Dordrecht: Springer Netherlands, 2007. http://dx.doi.org/10.1007/978-1-4020-5937-7_1.

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Bernardello, Gabriel. "A systematic survey of floral nectaries." In Nectaries and Nectar, 19–128. Dordrecht: Springer Netherlands, 2007. http://dx.doi.org/10.1007/978-1-4020-5937-7_2.

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Nepi, Massimo. "Nectary structure and ultrastructure." In Nectaries and Nectar, 129–66. Dordrecht: Springer Netherlands, 2007. http://dx.doi.org/10.1007/978-1-4020-5937-7_3.

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Conference papers on the topic "Nectar"

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de Oliveira, Etienne C. R., and Célio V. N. de Albuquerque. "NECTAR." In the 2009 ACM symposium. New York, New York, USA: ACM Press, 2009. http://dx.doi.org/10.1145/1529282.1529290.

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Covaci, Alexandra, Simone Madeo, Patrick Motylinski, and Stéphane Vincent. "NECTAR." In ICSE '18: 40th International Conference on Software Engineering. New York, NY, USA: ACM, 2018. http://dx.doi.org/10.1145/3194113.3194116.

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Laviole, Jeremy, Lauren Thevin, Jeremy Albouys-Perrois, and Anke Brock. "Nectar." In VRIC '18: Virtual Reality International Conference - Laval Virtual VRIC '18. New York, NY, USA: ACM, 2018. http://dx.doi.org/10.1145/3234253.3234317.

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Rubanova, O. A. "NECTAR PRODUCTIVITY OF SUNFLOWER LINES AND HYBRIDS." In 11-я Всероссийская конференция молодых учёных и специалистов «Актуальные вопросы биологии, селекции, технологии возделывания и переработки сельскохозяйственных культур». V.S. Pustovoit All-Russian Research Institute of Oil Crops, 2021. http://dx.doi.org/10.25230/conf11-2021-89-93.

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Common sunflower is an entomophilous crop; therefore, the presence of pollinating insects is necessary for the realization of the potential productivity of plants. Nectar is the main attractant of sunflower. In this work we determined the nectar bearing capacity and sugar content (dry matter content) of nectar in tubular flowers of various sunflower genotypes using microcapillary tubes with an inner diameter of 0.25 mm and an outside diameter of 0.50 mm. We noted the maximum amount of nectar in a line of genetic collection MVG-8 – 0.32 mg/flower. We observed the maximum value of sugar content in hybrids NK Brio and Factor – 61 and 57 %, respectively. The Oksi hybrid had the minimum values in the amount of 0.11 mg/flower and 21 % of the nectar sugar content.
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Cooper, E. C., P. A. Steenkiste, R. D. Sansom, and B. D. Zill. "Protocol implementation on the Nectar Communication Processor." In the ACM symposium. New York, New York, USA: ACM Press, 1990. http://dx.doi.org/10.1145/99508.99545.

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Lichtenberg, Elinor M. "Context dependency of bumble bee nectar robbing." In 2016 International Congress of Entomology. Entomological Society of America, 2016. http://dx.doi.org/10.1603/ice.2016.113337.

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Naumann, Christopher Lindsay, J. Bolmont, P. Corona, E. Delagnes, D. Dzahini, F. Feinstein, D. Gascon, et al. "NECTAR: New electronics for the Cherenkov Telescope Array." In HIGH ENERGY GAMMA-RAY ASTRONOMY: 5th International Meeting on High Energy Gamma-Ray Astronomy. AIP, 2012. http://dx.doi.org/10.1063/1.4772377.

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Steenkiste, Peter. "Analyzing communication latency using the Nectar communication processor." In Conference proceedings. New York, New York, USA: ACM Press, 1992. http://dx.doi.org/10.1145/144179.144278.

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Smith, Ty. "Influence of cultural practices on soybean nectar production." In 2016 International Congress of Entomology. Entomological Society of America, 2016. http://dx.doi.org/10.1603/ice.2016.109936.

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NAUMANN, Christopher, Julien Bolmont, Pascal Corona, Eric Delagnes, Daniel Dzahini, Fabrice Feinstein, David GASCON, et al. "NECTAR: New Electronics for the Cherenkov Telescope Array." In International Workshop on New Photon-detectors. Trieste, Italy: Sissa Medialab, 2013. http://dx.doi.org/10.22323/1.158.0030.

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Reports on the topic "Nectar"

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Steenkiste, Peter. Gigabit Nectar: Architecture and Performance. Fort Belvoir, VA: Defense Technical Information Center, September 1995. http://dx.doi.org/10.21236/ada303091.

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Landolt, Peter, Ezra Dunkelblum, Robert Heath, and Moshe Kehat. Host Plant Kairomonal Effects on Heliothis Mate-Finding Behavior. United States Department of Agriculture, February 1993. http://dx.doi.org/10.32747/1993.7613016.bard.

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We investigated the possible attraction of species of Helicoverpa and Heliothis to host plant odors and to male pheromone as a prelude to a larger investigation of host chemical effects on moth sexual and reproductive behavior. Both sexes of H. armigera and H. peltigera were attracted to particular host plants or host plant extracts. Heliothis virescens was also found to be attracted to a flowering shrub it may use as a nectar source. Unmated females of H. armigera and H. peltigera were attracted to live males and to a male pheromone extract prepared from exposed filter papers in cages of males. Some attraction of unmated female H. zea to males was also evident, but at much lower response rate.
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Hull, E. L. Mechanically Cooled Large-Volume Germanium Detector Systems for Neclear Explosion Monitoring DOENA27323-2. Office of Scientific and Technical Information (OSTI), October 2006. http://dx.doi.org/10.2172/894164.

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Hefetz, Abraham, and Justin O. Schmidt. Use of Bee-Borne Attractants for Pollination of Nonrewarding Flowers: Model System of Male-Sterile Tomato Flowers. United States Department of Agriculture, October 2003. http://dx.doi.org/10.32747/2003.7586462.bard.

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The use of bee natural product for enhancing pollination is especially valuable in problematic crops that are generally avoided by bees. In the present research we attempted to enhance bee visitation to Male Sterile (M-S) tomato flowers generally used in the production of hybrid seeds. These flowers that lack both pollen and nectar are unattractive to bees that learn rapidly to avoid them. The specific objects were to elucidate the chemical composition of the exocrine products of two bumble bee species the North American Bombus impatiens and the Israeli B. terrestris. Of these, to isolate and identify a bee attractant which when sprayed on M-S tomato flowers will enhance bee visitation, and to provide a procedure of the pheromone application regime. During the research we realized that our knowledge of B. impatiens is too little and we narrowed the objective to learning the basic social behavior of the bees and the pattern of foraging in a flight chamber and how it is affected by biogenic amines. Colonies of B. impatiens are characterized by a high number of workers and a relatively small number of queens. Size differences between queens and workers are pronounced and the queen seems to have full control over egg laying. Only about 9% of the workers in mature colonies had mature oocytes, and there were no signs of a "competition phase" as we know in B. terrestris. Queens and workers differ in their exocrine bouquet. Queen's Dufour's gland possesses a series of linear, saturated and unsaturated hydrocarbons whereas that of workers contains in addition a series of wax-type esters. Bees were trained to either visit or avoid artificially scented electronic flowers in a flight chamber. Since bee also learned to avoid scented non-rewarding flowers we attempted to interfere with this learning. We tested the effect of octopamine, a biogenic amine affecting bee behavior, on the choice behavior of free-flying bumblebees. Our results show that octopamine had no significant effect on the bees' equilibrium choice or on the overall rate of the behavioral change in response to the change in reward. Rather, octopamine significantly affected the time interval between the change in reward status and the initiation of behavioral change in the bee. In B. terrestris we studied the foraging pattern of the bees on tomato flowers in a semi commercial greenhouse in Yad Mordechai. Bee learned very quickly to avoid the non- rewarding M-S flowers, irrespective of their arrangement in the plot, i.e., their mixing with normal, pollen bearing flowers. However, bees seem to "forget" this information during the night since the foraging pattern repeats itself the next morning. Several exocrine products were tested as visitation enhancers. Among these, tarsal gland extracts are the most attractive. The compounds identified in the tarsal gland extract are mostly linear saturated hydrocarbons with small amounts of unsaturated ones. Application was performed every second day on leaves in selected inflorescences. Bee visitation increased significantly in the treated inflorescences as compared to the control, solvent treated. Treatment of the anthers cone was more effective than on the flower petals or the surrounding leaves. Methanol proved to be a non-flower-destructive solvent. We have shown that bumble bees (B. terrestris) can be manipulated by bee-borne attractants to visit non-rewarding flowers. We have further demonstrated that the bees learning ability can be manipulated by applying exogenously octopamine. Both methods can be additively applied in enhancing pollination of desired crops. Such manipulation will be especially useful in tomato cultivation for hybrid seed production.
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Perl, Avichai, Bruce I. Reisch, and Ofra Lotan. Transgenic Endochitinase Producing Grapevine for the Improvement of Resistance to Powdery Mildew (Uncinula necator). United States Department of Agriculture, January 1994. http://dx.doi.org/10.32747/1994.7568766.bard.

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The original objectives are listed below: 1. Design vectors for constitutive expression of endochitinase from Trichoderma harzianum strain P1. Design vectors with signal peptides to target gene expression. 2. Extend transformation/regeneration technology to other cultivars of importance in the U.S. and Israel. 3. Transform cultivars with the endochitinase constructs developed as part of objective 1. A. Characterize foliar powdery mildew resistance in transgenic plants. Background of the topic Conventional breeding of grapevines is a slow and imprecise process. The long generation cycle, large space requirements and poor understanding of grapevine genetics prevent rapid progress. There remains great need to improve existing important cultivars without the loss of identity that follows from hybridization. Powdery mildew (Uncinula necator) is the most important fungal pathogen of grapevines, causing economic losses around the world. Genetic control of powdery mildew would reduce the requirement for chemical or cultural control of the disease. Yet, since the trait is under polygenic control, it is difficult to manipulate through hybridization and breeding. Also, because grapevines are heterozygous and vegetatively propagated cultivar identity is lost in the breeding process. Therefore, there is great need for techniques to produce transgenic versions of established cultivars with heterologous genes conferring disease resistance. Such a gene is now available for control of powdery mildew of grapevines. The protein coded by the Endochitinase gene, derived from Trichoderma harzianum, is very effective in suppressing U. necator growth. The goal of this proposal is to develop transgenic grapevines with this antifungal gene, and to test the effect of this gene on resistance to powdery mildew. Conclusions, achievements and implications Gene transfer technology for grape was developed using commercial cultivars for both wine and table grapes. It paved the way for a new tool in grapevine genetic studies enabling the alteration of specific important traits while maintaining the essential features of existing elite cultivars. Regeneration and transformation technologies were developed and are currently at an advanced stage for USA wine and Israeli seedless cultivars, representing the cutting edge of grape genetic engineering studies worldwide. Transgenic plants produced are tested for powdery mildew resistance in greenhouse and field experiments at both locations. It is our ultimate goal to develop transgenic grapes which will be more efficient and economical for growers to produce, while also providing consumers with familiar products grown with reduced chemical inputs.
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Mendo, Tania, Sophie Smout, Johanna Ransijn, Ian Durbach, Paddy McCann, Swithun Crowe, Ariadna Carulla Fàbrega, Irene de Prado, and Mark James. Scottish Inshore Fisheries Integrated Data System (SIFIDS): work package 8B final report identifying fishing activities and their associated drivers. Edited by Hannah Ladd-Jones. Marine Alliance for Science and Technology for Scotland (MASTS), 2019. http://dx.doi.org/10.15664/10023.23463.

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[Extract from Executive Summary] This Work Package (WP8B) of the SIFIDS project focused on vessels that are 12 m or under in length, use static gear (pots or creels), and primarily target lobsters (Homarus gammarus), crabs (Cancer pagurus and Necora puber), and prawns (Nephrops norvegicus). WP8B had two principal objectives: 1. Identify fishing activity profiles for static gear vessels in the inshore fleet prosecuting lobsters, crabs and nephrops. 2. Incorporate effort, biological data, socio-economic data, environmental data to understand fishing behaviour
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Brøgger, Benedicte. Evaluation report on the NECA-NHO collaboration program 2003-2011. Oslo: Arbeidsforskningsinstituttet, 2012. http://dx.doi.org/10.7577/afi/fou/2012/2.

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Schipper, Youdi, Isaac Mbiti, and Mauricio Romero. Designing and Testing a Scalable Teacher Incentive Programme in Tanzania. Research on Improving Systems of Education (RISE), September 2022. http://dx.doi.org/10.35489/bsg-rise-ri_2022/044.

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School participation in Tanzania has increased dramatically over the past two decades: primary school enrolment increased from 4.9 million in 2001 to 10.9 million in 2020. While 81 percent of primary-school-age children are currently enrolled, over the last ten years, the primary completion rate has dropped and remains below 70 percent since 2015 (data from UNESCO Institute for Statistics).1 Despite improvements in enrolment, indicators of foundational learning remain low. According to the 2020 report of the Standard Two National Assessment (STNA), conducted by the National Examinations Council of Tanzania (NECTA), in 2019 five percent of Grade 2 students pass the benchmark for reading proficiency (“Can correctly read exactly 50 words of the passage in one minute and with 80 percent or higher comprehension”). The report finds that 17 percent of students pass the benchmark (80 percent correct) of the addition and subtraction sub-tasks. These outcomes are not the result of students’ lack of academic aspiration: according to the RISE Tanzania baseline survey, 73 percent of Grade 2 and 3 students say they would like to complete secondary school or university. In a recent report, the Global Education Evidence Advisory Panel (World Bank, 2020) asked what programmes and policies are the most cost-effective instruments for addressing the learning crisis and improving learning for all children. The report creates three categories: the “great buys” category includes programmes that provide very low-cost but salient information on the benefits, costs, and quality of education. The “good buys” category includes programmes that provide structured pedagogy, instruction targeted by learning level, merit-based scholarships and pre-school interventions. Finally, the category “promising but low-evidence” includes teacher accountability and incentive reforms. KiuFunza, a teacher performance pay programme in Tanzania, fits this last category. KiuFunza (shorthand for Kiu ya Kujifunza or Thirst to Learn) provides test-score linked cash incentives to teachers in Grades 1, 2, and 3 to increase foundational literacy and numeracy outcomes for students. The programme is managed by Twaweza East Africa, a Civil Society Organization, and was set up to provide evidence on the impact of teacher incentives in a series of experimental evaluations. This note discusses the rationale for teacher incentives in Tanzania, the design elements of KiuFunza and preliminary results for the most recent phase of KiuFunza (this phase was implemented in 2019-2021 and the impact evaluation is part of the RISE Tanzania research agenda).
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Grumet, Rebecca, Rafael Perl-Treves, and Jack Staub. Ethylene Mediated Regulation of Cucumis Reproduction - from Sex Expression to Fruit Set. United States Department of Agriculture, February 2010. http://dx.doi.org/10.32747/2010.7696533.bard.

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Reproductive development is a critical determinant of agricultural yield. For species with unisexual flowers, floral secualdifferentation adds additional complexity, that can influenec productivity. The hormone ethylene has long, been known to play a primary role in sex determination in the Cucumis species cucumber (C. sativus) and melon (C. melo). Our objectives were to: (1) Determine critical sites of ethylene production and perception for sex determination; (2) Identify additional ethylene related genes associated with sex expression; and (3) Examine the role of environment ami prior fruit set on sex expression, pistillate flower maturation, and fruit set. We made progress in each of these areas. (1) Transgenic melon produced with the Arabidopsis dominant negative ethylene perception mutant gene, etrl-1, under the control of floral primordia targeted promoters [AP3 (petal and stamen) and CRC (carpel and nectary)], showed that ethylene perception by the stamen primordia, rather than carpel primordia, is critical for carpel development at the time of sex determination. Transgenic melons also were produced with the ethylene production enzyme gene. ACS, encoding l-aminocyclopropane-lcarboylate synthase, fused to the AP3 or CRC promoters. Consistent with the etr1-1 results, CRC::ACS did not increase femaleness; however, AP3::ACS reduced or eliminated male flower production. The effects of AP3:ACS were stronger than those of 35S::ACS plants, demonstratin g the importance of targeted expression, while avoiding disadvantages of constitutive ethylene production. (2) Linkage analysis coupled with SNP discovery was per formed on ethylene and floral development genes in cucumber populations segregating for the three major sex genes. A break-through towards cloning the cucumber M gene occurred when the melon andromonoecious gene (a), an ACS gene, was cloned in 2008. Both cucumber M and melon a suppress stamen development in pistillate flowers. We hypothesized that cucumber M could be orthologous to melon a, and found that mutations in CsACS2 co-segregated perfectly with the M gene. We also sought to identify miRNA molecules associated with sex determination. miRNA159, whose target in Arabidopsis is GAMYB[a transcription factor gene mediating response to10 gibberellin (GA)], was more highly expressed in young female buds than male. Since GA promotes maleness in cucumber, a micro RNA that counteracts GAMYB could promote femaleness. miRNA157, which in other plants targets transcription factors involved in flower development , was expressed in young male buds and mature flower anthers. (3) Gene expression profiling showed that ethylene-, senescence-, stress- and ubiquitin-related genes were up-regulated in senescing and inhibited fruits, while those undergoing successful fruit set up-regulated photosynthesis, respiration and metabolic genes. Melon plants can change sex expression in response to environmental conditions, leading to changes in yield potential. Unique melon lines with varying sex expression were developed and evaluated in the field in Hancock, Wisconsin . Environmental changes during the growing season influenced sex expression in highly inbred melon lines. Collectively these results are of significance for understanding regulation of sex expression. The fact that both cucumber sex loci identified so far (F and M) encode isoforms of the same ethylene synthesis enzyme, underscores the importance of ethylene as the main sex determining hormone in cucumber. The targeting studies give insight into developmental switch points and suggest a means to develop lines with earlier carpel-bearing flower production and fruit set. These results are of significance for understanding regulation of sex expression to facilitate shorter growing seasons and earlier time to market. Field results provide information for development of management strategies for commercial production of melon cultivars with different sex expression characteristics during fruit production.
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Reisch, Bruce, Avichai Perl, Julie Kikkert, Ruth Ben-Arie, and Rachel Gollop. Use of Anti-Fungal Gene Synergisms for Improved Foliar and Fruit Disease Tolerance in Transgenic Grapes. United States Department of Agriculture, August 2002. http://dx.doi.org/10.32747/2002.7575292.bard.

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Original objectives . 1. Test anti-fungal gene products for activity against Uncinula necator, Aspergillus niger, Rhizopus stolonifer and Botrytis cinerea. 2. For Agrobacterium transformation, design appropriate vectors with gene combinations. 3. Use biolistic bombardment and Agrobacterium for transformation of important cultivars. 4. Characterize gene expression in transformants, as well as level of powdery mildew and Botrytis resistance in foliage of transformed plants. Background The production of new grape cultivars by conventional breeding is a complex and time-consuming process. Transferring individual traits via single genes into elite cultivars was proposed as a viable strategy, especially for vegetatively propagated crops such as grapevines. The availability of effective genetic transformation procedures, the existence of genes able to reduce pathogen stress, and improved in vitro culture methods for grapes, were combined to serve the objective of this proposal. Effective deployment of resistance genes would reduce production costs and increase crop quality, and several such genes and combinations were used in this project. Progress The efficacy of two-way combinations of Trichoderma endochitinase (CHIT42), synthetic peptide ESF12 and resveratrol upon the control of growth of Botrytis cinerea and Penicillium digitatum were evaluated in vitro. All pairwise interactions were additive but not synergistic. Per objective 2, suitable vectors with important gene combinations for Agrobacterium transformation were designed. In addition, multiple gene co-transformation by particle bombardment was also tested successfully. In New York, transformation work focused on cultivars Chardonnay and Merlot, while the technology in Israel was extended to 41B, R. 110, Prime, Italia, Gamay, Chardonnay and Velika. Transgenic plant production is summarized in the appendix. Among plants developed in Israel, endochitinase expression was assayed via the MuchT assay using material just 1-5 days after co-cultivation. Plants of cv. Sugraone carrying the gene coding for ESF12, a short anti-fungal lytic peptide under the control of the double 358 promoter, were produced. Leaf extracts of two plants showed inhibition zones that developed within 48 h indicating the inhibitory effect of the leaf extracts on the six species of bacteria. X fastidiosa, the causal organism of Pierce's disease, was very sensitive to leaf extracts from ESF12 transformed plants. Further work is needed to verify the agricultural utility of ESF12 transformants. In New York, some transformants were resistant to powdery mildew and Botrytis fruit rot. Major conclusions, solutions, achievements and implications The following scientific achievements resulted from this cooperative BARD project: 1. Development and improvement of embryogenesis and tissue culture manipulation in grape, while extending these procedures to several agriculturally important cultivars both in Israel and USA. 2. Development and improvement of novel transformation procedures while developing transformation techniques for grape and other recalcitrant species. 3. Production of transgenic grapevines, characterization of transformed vines while studying the expression patterns of a marker gene under the control of different promoter as the 35S CaMV in different part of the plants including flowers and fruits. 4. Expression of anti-fungal genes in grape: establishment of transgenic plants and evaluation of gene expression. Development of techniques to insert multiple genes. 5. Isolation of novel grape specific promoter to control the expression of future antimicrobial genes. It is of great importance to report that significant progress was made in not only the development of transgenic grapevines, but also in the evaluation of their potential for increased resistance to disease as compared with the non engineered cultivar. In several cases, increased disease resistance was observed. More research and development is still needed before a product can be commercialized, yet our project lays a framework for further investigations.
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