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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
161

Analysis Of Environmental Cues Causing The Seasonal Change In Pgm (phosphoglucomutase) Allozyme Frequencies In Honeybees (apis Mellifera L.)

Doke, Mehmet Ali 01 November 2012 (has links) (PDF)
In an earlier project completed in our laboratory a seasonal fluctuation in Phosphoglucomutase (PGM) phenotype frequencies was found, so that the winter bees were almost all heterozygotes and long lived than the summer bees among which homozygotes were significantly at high frequencies at Pgm locus. Same results were obtained in populations of three subspecies, A. m. meda, A. m. caucasica, and A. m. carnica from different climatic regions. In the current study environmental cues related with seasonal change in PGM phenotype frequency was examined along with the correlation between PGM heterozygosity and overwintering success. Cessation of food influx was found to be effective by itself as an environmental cue that causes a sudden and sharp increase in PGM heterozygosity. In addition to that, PGM heterozygosity of the colonies with greater overwintering success was found to be significantly higher than the ones with intermediate or low overwintering success. Benefiting from the previous studies and the results of current study, ethyl oleate was suggested as a chemical signal that functions in the regulation of PGM heterozygosity.
162

Habituation towards environmental enrichment in captive bears and its effect on stereotypic behaviours.

Anderson, Claes January 2008 (has links)
The benefits gained by the presentation of environmental enrichment (EE) to captive animals are widely recognized. Few studies have, however, studied how to maximize the effect of EE. Repeated presentations of EE may cause a reduced interest towards the EE device, called habituation. To study the effect of habituation towards EE, behavioural data from 14 captive Sloth bears (Melursus ursinus) were collected during two different EE treatments. In treatment one, honey logs were presented for five consecutive days (ConsEE). In treatment two, the logs were presented every alternative day for five days (AltEE). The different treatments both showed a significant effect on responsiveness toward the EE, however, leaving gap days inbetween presentations in AltEE showed no reliable reduction in habituation. Both treatments significantly reduced stereotypies, however, only ConsEE reduced levels of stereotypies long term. Explorative behaviours, which are the most prominent behaviours in the wild, increased during both treatments. This is consistent with previous findings (Fischbacher & Schmid 1999, Grandia et al. 2001) that EE increases natural behaviours, which has been desribed as an indication of improved welfare (Carlstead et al. 1991 etc.). Other behavioural categories such as social and passiva behaviours were unaffected by the EE presentations. THe results show that it is possible to increase the effectiveness of EE by simple means in order to ensure animal welfare.
163

’Paid pollination’ – en tjänst för odlade grödor och biodiversitet : Analys av den kommersiella pollineringens utbredning och utveckling i Taranaki-regionen, Nya Zeeland

Andwinge, Maria January 2011 (has links)
Pollinering är avgörande för ett antal kommersiella grödor samt för olika växtarter i inhemsk vegetation. Honungsbi (Apis mellifera) är en av de viktigaste pollinerarna. I regionen Taranaki i Nya Zeeland finns två aspekter av kommersiell pollinering, dels betalar många biodlare för tillgång till manuka för de antibakteriella egenskaperna honungen får av den, dels betalar frukt- och grönsaksodlare för pollinering av sina grödor. Markägare kan ha ett intresse av att spara manuka på sina marker och få en utkomst från biodlarna genom att dessa betalar för åtkomsten. Studien syftar till att klarlägga de effekter som kommersiell pollinering har i Taranaki-regionen idag och för framtida användning och har utgått från intervjuer med biodlare, frukt- och grönsaksodlare och personer som representerar myndigheterna. Resultaten visar att de ekonomiska effekterna av kommersiell pollinering i dag i Taranaki-regionen är relativt små. Även den kommersiella pollineringens roll för skydd och förvaltning av inhemsk natur undersöks. Kommersiell pollinering kan vara en viktig del inom naturskydd men är samtidigt beroende på om interaktionen med andra bin kan vara skadlig. Pollineringstjänster kan utvecklas dels genom information till markägare och jordbrukare, dels genom marknadsföring från biodlare. / Pollination is crucial for a number of commercial crops as well as for native vegetation. The honey bee (Apis mellifera) is one of the most important pollinators. In the Taranaki region in New Zealand there are two aspects of commercial pollination; beekeepers pay for access to manuka due to the antibacterial quality it gives the honey and orchardists pay for pollination of their crops. Landowners could have an interest in managing the manuka and having beekeepers paying for the access. This study seeks to elucidate the effects that commercial pollination has in Taranaki region, today as well as for future use, through interviews with beekeepers, orchardists and authority personnel. The results show that the effects of commercial pollination in Taranaki are of minor extent. Also the role commercial pollination plays for environmental management is highlighted. Commercial pollination may be a part of nature protection and play a particular role in effort to increase biodiversity, but it is much depending on the interaction with native bees. Pollination services may be developed in different ways including informing landowners and farmers and marketing of beekeepers.
164

Effect of pollen diet and honey bee (apis mellifera l.) primer pheromones on worker bee food producing glands

Peters, Lizette Alice 15 May 2009 (has links)
This thesis examines three factors that may influence the change in protein content and size of the brood food glands in honey bees. Effects on the mandibular gland, involved in the production of brood food and in royal jelly, have not been examined in relation to primer pheromones while effects on the hypopharyngeal glands, also involved in the production of brood food, have not been examined in relation to queen mandibular pheromone. This thesis provides preliminary insight into how these pheromones affect the extractable protein content of brood food glands. The first study in this thesis assessed the effects of brood pheromone (BP), queen mandibular pheromone (QMP), and pollen presence on the protein content of hypopharyngeal and mandibular glands of the honey bee. In this study, newly emerged bees were caged for 12 days in one of eight treatments: Queenless state: 1) control (no pollen + no pheromone), 2) pollen, 3) BP, 4) BP + pollen; Queenright state: 1) QMP, 2) QMP + pollen, 3) BP + QMP, 4) BP + QMP + pollen. This study indicated that regardless of pheromone treatment, the most influential factor on gland protein content and size was pollen. The second experiment examined effects of varying pollen dilution on hypopharyngeal and mandibular gland protein content, bee mass, and lipid content of the honey bee. In this experiment, newly emerged bees were caged for 7 days and fed one of five treatments: pollen, 1:1 pollen: cellulose (vol:vol), 1:2 pollen: cellulose (vol:vol); 1:3 pollen: cellulose (vol:vol), and cellulose. This study indicated that bees on the pollen diet were significantly greater than all other diluted diets in measurements of hypopharyngeal gland protein content, lipid content, and mass with significantly less consumption. However, mandibular gland protein content of bees on the pollen diet was significantly greater only from pure cellulose.
165

Nonparametric Methods for Point Processes and Geostatistical Data

Kolodziej, Elizabeth Young 2010 August 1900 (has links)
In this dissertation, we explore the properties of correlation structure for spatio-temporal point processes and a quantitative spatial process. Spatio-temporal point processes are often assumed to be separable; we propose a formal approach for testing whether a particular data set is indeed separable. Because of the resampling methodology, the approach requires minimal conditions on the underlying spatio-temporal process to perform the hypothesis test, and thus is appropriate for a wide class of models. Africanized Honey Bees (AHBs, Apis mellifera scutellata) abscond more frequently and defend more quickly than colonies of European origin. That they also utilize smaller cavities for building colonies expands their range of suitable hive locations to common objects in urban environments. The aim of the AHB study is to create a model of this quantitative spatial process to predict where AHBs were more likely to build a colony, and to explore what variables might be related to the occurrences of colonies. We constructed two generalized linear models to predict the habitation of water meter boxes, based on surrounding landscape classifications, whether there were colonies in surrounding areas, and other variables. The presence of colonies in the area was a strong predictor of whether AHBs occupied a water meter box, suggesting that AHBs tend to form aggregations, and that the removal of a colony from a water meter box may make other nearby boxes less attractive to the bees.
166

Effect Of Ultrasound And High Hydrostatic Pressure (hhp) On Liquefaction And Quality Parameters Of Selected Honey Varieties

Basmaci, Ipek 01 February 2010 (has links) (PDF)
Heat treatment (around 50&deg / C) is a major step in honey filling and packaging that is applied before filtration to decrease viscosity, reduce the moisture level, to destroy yeasts, liquefy crystals and delay crystallization. As a result, formation of Hydroxy Methyl Furfural (HMF), decrease in enzymatic activity, color deterioration, decrease in viscosity and many other structural changes are observed. HMF is produced as a result of Maillard reaction and/or hexose dehydration -which is undesirable-, practically, it is found in fresh honey in low levels, and increases due to heat treatment, storage temperature, pH (acidity) and sugar concentration of honey. HMF level and diastase number are important quality parameters and shelf life indicators of honey. Alternatives of v heat treatment may be the use of ultrasound and high hydrostatic pressure (HHP) to decrease viscosity, liquefy honey and thus minimise adverse affects of heat treatment. Therefore, the aim of this study is to evaluate the effect of HHP (220-330 MPa, 50-60&deg / C, time) and ultrasound (24 kHz) on liquefaction and quality parameters (HMF, diastase number, color and viscosity) of different honey varieties (sunflower, cotton and canola) and to compare the changes with heat treated (50&deg / C and 60&deg / C, time) and untreated honey. Based on the results of the chemical and physical analysis, for HHP treatment the best treatment combination was determined as 220 MPa, 50&deg / C, 106 min. For ultrasound treatment the best treatment combinations were determined as 7 mm probe- 0.5 cycle (batch) applications. On this basis the study points out that Ultrasound and HHP can be suggested as alternative methods to traditional thermal treatment for the liquefaction of honey crystals. When compared to thermal treatment, Ultrasound is advantageous in shorter application times, slight changes in quality parameters and ease in operation. HHP treatment is also an alternative method with shorter application times and lower HMF values.
167

A Model For Heat Transfer In A Honey Bee Swarm

Bask, Tanmay 12 1900 (has links)
During spring, it has been observed that several thousand bees leave their hive, and settle on some object such as a tree branch. Some of the scout bees search for a suitable place where a new hive can be set up, while the rest collect together to form a swarm. Heinrich (J. of Exp. Biology 91 (1981) 25; Science 212 (1981) 565; Scientific American 244:6 (1981) 147) has done some experiments with free and captive swarms. His observations are as follows. (1)The core (centre) temperature is around 35°C irrespective of the ambient temperature. (2)The mantle (outer surface) temperature exceeds the ambient temperature by 2- 3°C, provided the ambient temperature is greater than 20°C. Otherwise the mantle temperature is maintained around 17°C. (3) The temperature gradient vanishes just before take-off of the swarm. The present work attempts to predict temperature profiles in swarms and compare them with the data of Heinrich. A continuum model involving unsteady heat conduction and heat generation within the swarm is used. Heat loss from the outer surface of the swarm by free convection and radiation is accounted for approximately. To simplify the analysis, internal convection within the swarm is neglected. The energy balance equation is solved using the finite element method. The effective thermal conductivity (k) is determined by comparing model predictions with data for a swarm of dead bees. The estimated value of k is 0.20 W/m-K. Both spherical and a non-spherical axisymmetric shapes are considered. Considering axisymmetric swarms of live bees, temperature profiles are obtained using various heat generation functions which are available in literature. The effective thermal conductivity is assumed to be the same as that for the swarm of dead bees. Results based on a modified version of Southwick's heat generation function (The Behavior and Physiology of Bees, pp. 28-47, 1991) are qualitatively in accord with the data. The predicted maximum temperature within the swarm and the temperature at the lower surface of the swarm at the ambient temperature of 5°C are 34°C and 17-20°C, respectively. These are comparable to the measured values of 36°C and 19°C. The predicted maximum temperature within the swarm and the temperature at the lower surface of the swarm at the ambient temperature of 9°C are 36.5°C and 17-22°C, respectively. These are comparable to the measured values of 35°C and 19°C. The predicted oxygen consumption rates are 2.55 ml/g/hr for a swarm of 5284 bees at an ambient temperature Ta = 5°C and 1.15 ml/g/hr for 16,600 bees at Ta = 9°C. These are of the same order as the measured values (2 ml/g/hr for 5284 bees at Ta = 4.4DC and 0.45-0.55 ml/g/hr for 5284 bees at Ta = 10°C). Omholt and Lanvik (J. of Theoretical Biology, 120 (1986) 447) assumed a non-uniform steady state profile and used it to estimate the heat generation function. Using this function in the transient energy balance, it is found that their steady state profile is unstable.
168

Neue Ansätze in der Qualitätssicherung von Honig

Beckmann, Klaus 27 January 2009 (has links) (PDF)
Der erste Teil der Dissertation behandelt die Substanz Phenylacetaldehyd, welche im Honig ausgehend von der Aminosäure Phenylalanin als natürlicher Stoff, aber auch als Rückstand nach Einsatz als Bienenvertreibungsmittel vorliegen kann. Die in dieser Arbeit durchgeführten Untersuchungen zeigen, dass der Gehalt an Phenylalanin sowie äußere Bedingungen, denen Honige ausgesetzt sind, für die Konzentration an Phenylacetaldehyd maßgebend sind. Diese Parameter müssen mindestens bekannt sein, um entscheiden zu können, ob Phenylacetaldehyd als Rückstand im Honig vorliegt. Der zweite Teil befasst sich mit der Filtration von Honig, welche in manchen Ländern durchgeführt wird, um eine Kristallisation zu herauszuzögern. Es wurde eine Methode entwickelt, um illegale Beimischungen gefilterter Honige zu ungefilterten Honigen nachzuweisen. Dazu wird das Enzym Saccharase gelchromatographisch isoliert und diese Fraktion elektrophoretisch untersucht. Die Veränderung des Proteinspektrums lässt sich mit Hilfe einer densitometrischen Auswertung quantifizieren und zeigt gefilterten Honig auch in Mischungen bis zu einem Anteil von mindestens 15 % an.
169

Habituation towards environmental enrichment in captive bears and its effect on stereotypic behaviours.

Anderson, Claes January 2008 (has links)
<p>The benefits gained by the presentation of environmental enrichment (EE) to captive animals are widely recognized. Few studies have, however, studied how to maximize the effect of EE. Repeated presentations of EE may cause a reduced interest towards the EE device, called habituation. To study the effect of habituation towards EE, behavioural data from 14 captive Sloth bears (<em>Melursus ursinus</em>) were collected during two different EE treatments. In treatment one, honey logs were presented for five consecutive days (ConsEE). In treatment two, the logs were presented every alternative day for five days (AltEE). The different treatments both showed a significant effect on responsiveness toward the EE, however, leaving gap days inbetween presentations in AltEE showed no reliable reduction in habituation. Both treatments significantly reduced stereotypies, however, only ConsEE reduced levels of stereotypies long term. Explorative behaviours, which are the most prominent behaviours in the wild, increased during both treatments. This is consistent with previous findings (Fischbacher & Schmid 1999, Grandia et al. 2001) that EE increases natural behaviours, which has been desribed as an indication of improved welfare (Carlstead et al. 1991 etc.). Other behavioural categories such as social and passiva behaviours were unaffected by the EE presentations. THe results show that it is possible to increase the effectiveness of EE by simple means in order to ensure animal welfare.</p>
170

The costs and benefits of resistance and tolerance behaviors against Varroa mite (Varroa destructor Anderson and Trueman) in honey bee (Apis mellifera L.)

Bahreini, Rassol 16 December 2014 (has links)
Managed honey bee colonies face severe winter losses in northern climates. In my studies, interactions between genotypes of bees (genetically selected stock and unselected stock) with different levels of resistance and tolerance to varroa mites were assessed under a variety of treatment combinations to quantify effects of queen pheromone, acaricide treatment, wintering method, ventilation condition and pathogen infection on the costs and benefits associated with mite removal and mite-tolerance behaviors. In most of the experiments, mite-resistance caused greater varroa mite mortality within selected stock relative to unselected stock. Artificial and natural sources of queen pheromone caused greater varroa mite mortality within honey bee colonies relative to queenless colonies. While mite resistance had significant benefits, I showed that when producers selected colonies containing some mite resistance traits, it was traits associated with mite-tolerance and not mite-resistance were maintained and contributed to wintering success. Tolerance was effective at two levels of mites as obtained by late autumn treatment of colonies with oxalic but treatment did not improve wintering performance of either stock. Selected stock showed greater colony size, survival and resulted in more viable colonies in spring in comparison to unselected stock with similar initial mite levels (0.16 mites per bee). Selected stock showed greater relative wintering success than unselected stock when wintered indoors than when wintered outdoors but indoor wintering improved colony survival in both stocks relative to outdoor wintering. Carbon dioxide level increased within the winter bee cluster when colonies were maintained under restricted-ventilation (mean 3.82±0.031%, range 0.43-8.44%) and restricted ventilation increased mite mortality by 138% relative to standard-ventilation (mean 1.29±0.031%, range 0.09-5.26%), but restricted-ventilation did not affect bee mortality in comparison to standard-ventilation. In a laboratory study, I showed that Nosema inoculation (with co-infections of N. ceranae and N. apis) suppressed the effectiveness of mite removal behavior within selected bees relative to unselected bees. N. ceranae was more abundant than N. apis. Bees with greater mite removal capacities had higher costs associated with varroa-resistance as indicated by greater bee mortality rates when inoculated with varroa but bee mortality was not affected in Nosema inoculated bees.

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