E-β-ocimene, a volatile brood pheromone involved in social regulation in the honey bee colony (Apis mellifera.

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Alban Maisonnasse

Full Text Available BACKGROUND: In honey bee colony, the brood is able to manipulate and chemically control the workers in order to sustain their own development. A brood ester pheromone produced primarily by old larvae (4 and 5 days old larvae was first identified as acting as a contact pheromone with specific effects on nurses in the colony. More recently a new volatile brood pheromone has been identified: E-β-ocimene, which partially inhibits ovary development in workers. METHODOLOGY AND PRINCIPAL FINDING: Our analysis of E-β-ocimene production revealed that young brood (newly hatched to 3 days old produce the highest quantity of E-β-ocimene relative to their body weight. By testing the potential action of this molecule as a non-specific larval signal, due to its high volatility in the colony, we demonstrated that in the presence of E-β-ocimene nest workers start to forage earlier in life, as seen in the presence of real brood. CONCLUSIONS/SIGNIFICANCE: In this way, young larvae are able to assign precedence to the task of foraging by workers in order to increase food stores for their own development. Thus, in the complexity of honey bee chemical communication, E-β-ocimene, a pheromone of young larvae, provides the brood with the means to express their nutritional needs to the workers.

Disc size regulation in the brood cell building behavior of leaf-cutter bee, Megachile tsurugensis.

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Kim, Jong-yoon

2007-12-01

The leaf-cutter bee, Megachile tsurugensis, builds a brood cell in a preexisting tunnel with leaf discs that she cuts in decreasing sizes and assembles them like a Russian matryoshka doll. By experimentally manipulating the brood cell, it was investigated how she regulates the size of leaf discs that fit in the brood cell's internal volume. When the internal volume was artificially increased by removing a bulk of leaf discs, she decreased the leaf disc size, although increasing it would have made the leaf disc more fitting in the increased internal volume. As a reverse manipulation, when the internal volume was decreased by inserting a group of inner layers of preassembled leaf discs to a brood cell, she decreased the leaf disc size, so that the leaf disc could fit in the decreased internal volume. These results suggest that she uses at least two different mechanisms to regulate the disc size: the use of some internal memory about the degree of building work accomplished in the first and of sensory feedback of dimensional information at the construction site in the second manipulation, respectively. It was concluded that a stigmergic mechanism, an immediate sensory feedback from the brood cell changed by the building work, alone cannot explain the details of the bee's behavior particularly with respect to her initial response to the first manipulation. For a more complete explanation of the behavior exhibited by the solitary bee, two additional behavioral elements, reinforcement of building activity and processing of dimensional information, were discussed along with stigmergy.

Effect of the presence of brood and fungus on the nest architecture and digging activity of Acromyrmex subterraneus Forel (Hymenoptera, Formicidae

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Carlos Magno dos Santos

Full Text Available ABSTRACT This study investigated the stimuli that trigger digging behavior in Acromyrmex subterraneus during nest building. The hypothesis was that the presence of the fungus garden and/or brood triggers the excavation of tunnels and chambers. For the experiment, the excavation rate of individually marked workers kept in plastic cylinders filled with soil was recorded. Four treatments were applied: (1 30 medium-sized workers, 5 g fungus garden and 30 brood items (larvae and pupae; (2 30 medium-sized workers and 5 g fungus garden; (3 30 medium-sized workers and 30 brood items; (4 30 medium-sized workers without fungus and brood. After 24 h, morphological parameters of nest structure (length and width of the chambers and tunnels in cm and the volume of excavated soil were recorded. In contrast to the expected findings, no change in morphological structure, rate of excavation by workers, or volume of excavated soil was observed between treatments, except for tunnel width, which was greater, when no brood or fungus garden was present. Thus, the results do not support the hypothesis that the fungus garden and/or brood are local stimuli for nest excavation or that they mold the internal architecture of the nest. Although this hypothesis was confirmed for Acromyrmex lundii and Atta sexdens rubropilosa, the same does not apply to A. subterraneus. The digging behavior of workers is probably the result of adaptation during nest building in different habitats.

Evaluation of drone brood removal for management of Varroa destructor (Acari: Varroidae) in colonies of Apis mellifera (Hymenoptera: Apidae) in the northeastern United States.

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Calderone, N W

2005-06-01

The efficacy of drone brood removal for the management of Varroa destructor Anderson & Trueman in colonies of the honey bee, A. mellifera L., was evaluated. Colonies were treated with CheckMite+ in the fall of 2002. The following spring, quantities of bees and brood were equalized, but colonies were not retreated. The brood nest of each colony consisted of 18 full-depth worker combs and two full-depth drone combs. Each worker comb had drone cells. Standard management practices were used throughout the season. Colonies were randomly assigned to one of two groups. In the control group, drone combs remained in place throughout the season. In the treatment group, drone combs were removed on 16 June, 16 July, 16 August, and 16 September and replaced with empty drone combs (16 June) or with drone combs removed on the previous replacement date. In the early fall, the average mite-to-bee ratio in the control group was significantly greater than the corresponding ratio in the treatment group. Drone brood removal did not adversely affect colony health as measured by the size of the worker population or by honey production. Fall worker populations were similar in the two groups. Honey production in treatment colonies was greater than or similar to production in control colonies. These data demonstrate that drone brood removal can serve as a valuable component in an integrated pest management program for V. destructor and may reduce the need for other treatments on a colony-by-colony basis.

Pathway profiles based on gene-set enrichment analysis in the honey bee Apis mellifera under brood rearing-suppressed conditions.

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Kim, Kyungmun; Kim, Ju Hyeon; Kim, Young Ho; Hong, Seong-Eui; Lee, Si Hyeock

2018-01-01

Perturbation of normal behaviors in honey bee colonies by any external factor can immediately reduce the colony's capacity for brood rearing, which can eventually lead to colony collapse. To investigate the effects of brood-rearing suppression on the biology of honey bee workers, gene-set enrichment analysis of the transcriptomes of worker bees with or without suppressed brood rearing was performed. When brood rearing was suppressed, pathways associated with both protein degradation and synthesis were simultaneously over-represented in both nurses and foragers, and their overall pathway representation profiles resembled those of normal foragers and nurses, respectively. Thus, obstruction of normal labor induced over-representation in pathways related with reshaping of worker bee physiology, suggesting that transition of labor is physiologically reversible. In addition, some genes associated with the regulation of neuronal excitability, cellular and nutritional stress and aggressiveness were over-expressed under brood rearing suppression perhaps to manage in-hive stress under unfavorable conditions. Copyright © 2017 Elsevier Inc. All rights reserved.

Cryptic extended brood care in the facultatively eusocial sweat bee Megalopta genalis.

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Quiñones, A E; Wcislo, W T

As a result of different brood cell provisioning strategies, nest-making insects may differ in the extent to which adults regularly provide extended parental care to their brood beyond nest defense. Mass-provisioning species cache the entire food supply needed for larval development prior to the oviposition and typically seal the brood cell. It is usually assumed that there is no regular contact between the adult(s) and brood. Here, we show that the bee, Megalopta genalis , expresses a form of cryptic brood care, which would not be observed during normal development. Following experimental injections of different provisioning materials into brood cells, foundresses reopened manipulated cells and the brood were aborted in some cases, implying that the foundresses assessed conditions within the cells. In aborted cells, foundresses sometimes laid a second egg after first removing dead larvae, previously stored pollen and contaminants. Our results show that hygienic brood care can be cryptic and hence may be more widespread than previously believed, lending support to the hypothesis that extended parental care is a preadaptation toward eusociality.

The Effect of Open Brood and Colony Strength on the Onset of Oviposition by Queen Bees

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Gąbka Jakub

2014-06-01

Full Text Available In bee colonies without open brood, e.g., after swarming, there is no need for royal jelly, and nurse bees thus do not produce it. According to many beekeepers, adding combs with open brood restarts the production of royal jelly by nurse bees, and the virgin queens then are better fed and start earlier oviposition. The purpose of this study was to investigate whether the presence of open brood and the strength of the colonies affect the onset of oviposition by queen bees. Open brood in colonies with virgins before and during mating flights did not accelerate the initiation of oviposition by the queens. In addition, no differences were identified in starting oviposition by queens in strong colonies of more than 30,000 worker bees, or in weak colonies with up to 1,000 workers. Overall, the results showed that neither open brood in the nests, nor the strength of the colonies affects the onset of oviposition by queen bees.

The influence of social structure on brood survival and development in a socially polymorphic ant: insights from a cross-fostering experiment.

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Purcell, Jessica; Chapuisat, M

2012-11-01

Animal societies vary in the number of breeders per group, which affects many socially and ecologically relevant traits. In several social insect species, including our study species Formica selysi, the presence of either one or multiple reproducing females per colony is generally associated with differences in a suite of traits such as the body size of individuals. However, the proximate mechanisms and ontogenetic processes generating such differences between social structures are poorly known. Here, we cross-fostered eggs originating from single-queen (= monogynous) or multiple-queen (= polygynous) colonies into experimental groups of workers from each social structure to investigate whether differences in offspring survival, development time and body size are shaped by the genotype and/or prefoster maternal effects present in the eggs, or by the social origin of the rearing workers. Eggs produced by polygynous queens were more likely to survive to adulthood than eggs from monogynous queens, regardless of the social origin of the rearing workers. However, brood from monogynous queens grew faster than brood from polygynous queens. The social origin of the rearing workers influenced the probability of brood survival, with workers from monogynous colonies rearing more brood to adulthood than workers from polygynous colonies. The social origin of eggs or rearing workers had no significant effect on the head size of the resulting workers in our standardized laboratory conditions. Overall, the social backgrounds of the parents and of the rearing workers appear to shape distinct survival and developmental traits of ant brood. © 2012 The Authors. Journal of Evolutionary Biology © 2012 European Society For Evolutionary Biology.

The Effect of Dietary Vitamin C on Carbohydrate Concentrations and Hydrolase Activity, During the Development of Honey Bee Worker Brood

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Farjan Marek; Żółtowska Krystyna; Lipiński Zbigniew; Łopieńska-Biernat Elżbieta; Dmitryjuk Małgorzata

2015-01-01

The colony collapse disorder is a growing problem world-wide. For this reason, we were prompted to search for natural and harmless agents that could improve the living conditions of honey bees. This group of agents includes exogenous antioxidants, such as ascorbic acid, which boost natural immunity. We analysed the effect of vitamin C supplementation on carbohydrate metabolism in the developing honey bee worker brood. The total carbohydrate content and the concentrations of glycogen, trehalos...

Cryptic extended brood care in the facultatively eusocial sweat bee Megalopta genalis

OpenAIRE

Quiñones Paredes, Andres; Wcislo, W.T.

2015-01-01

As a result of different brood cell provisioning strategies, nest-making insects may differ in the extent to which adults regularly provide extended parental care to their brood beyond nest defense. Mass-provisioning species cache the entire food supply needed for larval development prior to the oviposition and typically seal the brood cell. It is usually assumed that there is no regular contact between the adult(s) and brood. Here, we show that the bee, Megalopta genalis, expresses a form of...

Social regulation of ageing by young workers in the honey bee, Apis mellifera.

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Eyer, Michael; Dainat, Benjamin; Neumann, Peter; Dietemann, Vincent

2017-01-01

Organisms' lifespans are modulated by both genetic and environmental factors. The lifespan of eusocial insects is determined by features of the division of labor, which itself is influenced by social regulatory mechanisms. In the honey bee, Apis mellifera, the presence of brood and of old workers carrying out foraging tasks are important social drivers of ageing, but the influence of young adult workers is unknown, as it has not been experimentally teased apart from that of brood. In this study, we test the role of young workers in the ageing of their nestmates. We measured the impact of different social contexts characterized by the absence of brood and/or young adults on the lifespan of worker nestmates in field colonies. To acquire insight into the physiological processes occurring under these contexts, we analyzed the expression of genes known to affect honey bee ageing. The data showed that young workers significantly reduced the lifespan of nestmate workers, similar to the effect of brood on its own. Differential expression of vitellogenin, major royal jelly protein-1, and methylase transferase, but not methyl farneosate epoxidase genes suggests that young workers and brood influence ageing of adult nestmate workers via different physiological pathways. We identify young workers as an essential part of the social regulation of ageing in honey bee colonies. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Expression and Activity of Lysozyme in Apis Mellifera Carnica Brood Infested with Varroa Destructor

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Zaobidna Ewa A.

2017-12-01

Full Text Available Varroa destructor is a parasitic mite that attacks the honey bee, and previous studies have suggested that parasitosis caused by this mite is accompanied by immunosuppresion in the host. In this study, the effect of mite infestation on the expression of the lysozyme-1 (lys-1 gene and lysozyme activity in Apis mellifera carnica was determined. The experiment was carried out on the five developmental stages of honey bee workers and drones. Developmental and gender-related differences in gene expression and lysozyme activity were observed in a Varroa destructor-infested brood. The relative expression of the lys-1 gene increased in a infested worker brood and decreased in a drone brood except for P3 pupae. In the final stage of development, the lys-1 gene expression was significantly lower in infested newly emerged workers and drones. Changes in the relative expression of the lys-1 gene in infested individuals was poorly manifested at the level of enzyme activity, whereas at the two final stages of development (P5 and I there was a positive correlation between relative lys-1 expression and lysozyme activity in infested bees of both genders (r=0.988, r=0.999, respectively. The results of this study indicate that V. destructor influences the lysozyme-linked immune response in bees.

Mapping sleeping bees within their nest: spatial and temporal analysis of worker honey bee sleep.

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Klein, Barrett Anthony; Stiegler, Martin; Klein, Arno; Tautz, Jürgen

2014-01-01

Patterns of behavior within societies have long been visualized and interpreted using maps. Mapping the occurrence of sleep across individuals within a society could offer clues as to functional aspects of sleep. In spite of this, a detailed spatial analysis of sleep has never been conducted on an invertebrate society. We introduce the concept of mapping sleep across an insect society, and provide an empirical example, mapping sleep patterns within colonies of European honey bees (Apis mellifera L.). Honey bees face variables such as temperature and position of resources within their colony's nest that may impact their sleep. We mapped sleep behavior and temperature of worker bees and produced maps of their nest's comb contents as the colony grew and contents changed. By following marked bees, we discovered that individuals slept in many locations, but bees of different worker castes slept in different areas of the nest relative to position of the brood and surrounding temperature. Older worker bees generally slept outside cells, closer to the perimeter of the nest, in colder regions, and away from uncapped brood. Younger worker bees generally slept inside cells and closer to the center of the nest, and spent more time asleep than awake when surrounded by uncapped brood. The average surface temperature of sleeping foragers was lower than the surface temperature of their surroundings, offering a possible indicator of sleep for this caste. We propose mechanisms that could generate caste-dependent sleep patterns and discuss functional significance of these patterns.

Changes in infestation, cell cap condition, and reproductive status of Varroa destructor (Mesostigmata: Varrroidae) in brood exposed to honey bees with Varroa sensitive hygiene

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Honey bees (Apis mellifera L.) bred for Varroa sensitive hygiene (VSH) selectively remove pupae infested with Varroa destructor Anderson & Trueman from capped brood that is inserted into the nest. After one week, remaining brood cells tend to have been uncapped and recapped, and remaining mites are...

Mapping Sleeping Bees within Their Nest: Spatial and Temporal Analysis of Worker Honey Bee Sleep

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Klein, Barrett Anthony; Stiegler, Martin; Klein, Arno; Tautz, Jürgen

2014-01-01

Patterns of behavior within societies have long been visualized and interpreted using maps. Mapping the occurrence of sleep across individuals within a society could offer clues as to functional aspects of sleep. In spite of this, a detailed spatial analysis of sleep has never been conducted on an invertebrate society. We introduce the concept of mapping sleep across an insect society, and provide an empirical example, mapping sleep patterns within colonies of European honey bees (Apis mellifera L.). Honey bees face variables such as temperature and position of resources within their colony's nest that may impact their sleep. We mapped sleep behavior and temperature of worker bees and produced maps of their nest's comb contents as the colony grew and contents changed. By following marked bees, we discovered that individuals slept in many locations, but bees of different worker castes slept in different areas of the nest relative to position of the brood and surrounding temperature. Older worker bees generally slept outside cells, closer to the perimeter of the nest, in colder regions, and away from uncapped brood. Younger worker bees generally slept inside cells and closer to the center of the nest, and spent more time asleep than awake when surrounded by uncapped brood. The average surface temperature of sleeping foragers was lower than the surface temperature of their surroundings, offering a possible indicator of sleep for this caste. We propose mechanisms that could generate caste-dependent sleep patterns and discuss functional significance of these patterns. PMID:25029445

Mapping sleeping bees within their nest: spatial and temporal analysis of worker honey bee sleep.

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Barrett Anthony Klein

Full Text Available Patterns of behavior within societies have long been visualized and interpreted using maps. Mapping the occurrence of sleep across individuals within a society could offer clues as to functional aspects of sleep. In spite of this, a detailed spatial analysis of sleep has never been conducted on an invertebrate society. We introduce the concept of mapping sleep across an insect society, and provide an empirical example, mapping sleep patterns within colonies of European honey bees (Apis mellifera L.. Honey bees face variables such as temperature and position of resources within their colony's nest that may impact their sleep. We mapped sleep behavior and temperature of worker bees and produced maps of their nest's comb contents as the colony grew and contents changed. By following marked bees, we discovered that individuals slept in many locations, but bees of different worker castes slept in different areas of the nest relative to position of the brood and surrounding temperature. Older worker bees generally slept outside cells, closer to the perimeter of the nest, in colder regions, and away from uncapped brood. Younger worker bees generally slept inside cells and closer to the center of the nest, and spent more time asleep than awake when surrounded by uncapped brood. The average surface temperature of sleeping foragers was lower than the surface temperature of their surroundings, offering a possible indicator of sleep for this caste. We propose mechanisms that could generate caste-dependent sleep patterns and discuss functional significance of these patterns.

Cryptic extended brood care in the facultatively eusocial sweat bee Megalopta genalis

NARCIS (Netherlands)

Quiñones Paredes, Andres; Wcislo, W.T.

2015-01-01

As a result of different brood cell provisioning strategies, nest-making insects may differ in the extent to which adults regularly provide extended parental care to their brood beyond nest defense. Mass-provisioning species cache the entire food supply needed for larval development prior to the

Invasion of Varroa mites into honey bee brood cells

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Boot, W.J.

1995-01-01

The parasitic mite Varroa-jacobsoni is one of the most serious pests of Western honey bees, Apis mellifera. The mites parasitize adult bees, but reproduction only occurs while parasitizing on honey bee brood. Invasion into a

A comparison of the hygienic response of Africanized and European (Apis mellifera carnica honey bees to Varroa-infested brood in tropical Brazil

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Pia Aumeier

2000-12-01

Full Text Available In order to examine the significance of hygienic behavior for the tolerance to varroosis of Africanized honey bees, they were compared with non-tolerant Carniolans in tropical Brazil. Capped worker brood cells were artificially infested with living Varroa mites, and inspected some days later. Uncapping, disappearance of the introduced mite and removal of the pupa were recorded in a total of manipulated 3,096 cells during three summer seasons. The hygienic response varied between Africanized and Carniolan colonies, but this difference was significant only in one year, during which Africanized honey bees removed a significantly greater proportion of Varroa mites than European honey bees. A high proportion of the mites disappeared from artificially infested brood cells without damage to the pupae. The opening of the cell and the removal of the bee brood are independent traits of a graded response by adult workers towards mite-infested brood cells. We found a higher between-colony variation in the reaction towards Varroa-infested brood of Africanized honey bees compared to Carniolans. The overall similar response of the two bee types indicates that hygienic behavior is not a key factor in the tolerance to varroosis of Africanized bees in Brazil.Com o intuito de examinar o significado do comportamento higiênico na tolerância à varroose de abelhas africanizadas, elas foram comparadas com as não tolerantes Cárnicas no Brasil tropical. Células de cria de operárias operculadas foram artificialmente infestadas com ácaros Varroa vivos e inspecionadas alguns dias depois. Desoperculação, desaparecimento dos ácaros introduzidos e remoção da pupa foram anotados em um total de 3096 células manipuladas durante três verões. A resposta higiênica variou entre as colônias africanizadas e de Cárnicas, mas esta diferença foi significante apenas em um ano, durante o qual as abelhas africanizadas removeram uma proporção significantemente maior de �

Reconhecimento da prole por operárias companheiras e não companheiras de ninho em Acromyrmex laticeps nigrosetosus Forel, 1908 (Hymenoptera, Formicidae Brood recognition by workers of Acromyrmex laticeps nigrosetosus Forel, 1908 (Hymenoptera, Formicidae

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Danival José de Souza

2003-02-01

Full Text Available Estudou-se a capacidade de discriminação de formas jovens de Acromyrmex laticeps nigrosetosus por operárias adultas da mesma subespécie. Eram oferecidas, na área de forrageamento, larvas e pupas companheiras e não companheiras de ninho, sendo quantificado o comportamento frente a essas formas jovens. Foram utilizadas colônias oriundas do município de Paraopeba, MG, Brasil, mantidas em condições de laboratório. Os resultados evidenciaram que essa subespécie não é capaz de discriminar formas jovens companheiras e não companheiras de ninho, ou seja, transportaram indiscriminadamente as formas jovens oferecidas para o interior do ninho. Também não se observou diferença significativa para o tempo de resposta de aceitação de prole companheira e não companheira de ninho.This study investigated the behavioral response (acception or rejection of Acromyrmex laticeps nigrosetosus to their brood and to brood from different colonies of this subespecies. The four colonies used in the bioassays came from Paraopeba, MG, Brazil. Workers accepted either brood from their colonies or from different colonies. There was no significant difference on the time for brood acceptance (transport to the interior of the nest among nestmates and non-nestmates.

Lethal infection thresholds of Paenibacillus larvae for honeybee drone and worker larvae (Apis mellifera).

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Behrens, Dieter; Forsgren, Eva; Fries, Ingemar; Moritz, Robin F A

2010-10-01

We compared the mortality of honeybee (Apis mellifera) drone and worker larvae from a single queen under controlled in vitro conditions following infection with Paenibacillus larvae, a bacterium causing the brood disease American Foulbrood (AFB). We also determined absolute P. larvae cell numbers and lethal titres in deceased individuals of both sexes up to 8 days post infection using quantitative real-time PCR (qPCR). Our results show that in drones the onset of infection induced mortality is delayed by 1 day, the cumulative mortality is reduced by 10% and P. larvae cell numbers are higher than in worker larvae. Since differences in bacterial cell titres between sexes can be explained by differences in body size, larval size appears to be a key parameter for a lethal threshold in AFB tolerance. Both means and variances for lethal thresholds are similar for drone and worker larvae suggesting that drone resistance phenotypes resemble those of related workers. © 2010 Society for Applied Microbiology and Blackwell Publishing Ltd.

Behavioral Differentiation and Ovarian Development of Unmated Gynes, Queens, and Workers of Ectatomma vizottoi Almeida 1987 (Formicidae, Ectatomminae

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Alexsandro Santana Vieira

2012-01-01

Full Text Available Behavioral differentiation and ovarian development of unmated gynes, queens, and workers of Ectatomma vizottoi were investigated in laboratory conditions. Forty-one behavioral acts were identified and quantified for workers, 19 for queens and 24 for unmated gynes, for an overall species repertoire of 42 different behavioral acts. Ovipositing reproductive eggs was an exclusive task of the queen, whereas workers showed 15 caste-specific behaviors. The most important (frequent behaviors for the queens were brood care, immobility, and reproduction, and for workers were immobility, grooming/interaction, brood care, and foraging. Unmated gynes (not winged primarily showed immobility, brood care, grooming/interaction, and foraging. Analysis of ovarian development showed that unmated gynes had little-developed ovarioles, in contrast to queens. Queens and unmated gynes showed a clear behavioral differentiation, in which queens played the role of reproducers and unmated gynes performed activities belonging to the worker repertoire. Despite the presence of several breeding queens in the colony, functional monogyny was the rule.

Brooding fathers, not siblings, take up nutrients from embryos

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Sagebakken, Gry; Ahnesjö, Ingrid; Mobley, Kenyon B.; Gonçalves, Inês Braga; Kvarnemo, Charlotta

2010-01-01

It is well known that many animals with placenta-like structures provide their embryos with nutrients and oxygen. However, we demonstrate here that nutrients can pass the other way, from embryos to the parent. The study was done on a pipefish, Syngnathus typhle, in which males brood fertilized eggs in a brood pouch for several weeks. Earlier research has found a reduction of embryo numbers during the brooding period, but the fate of the nutrients from these ‘reduced’ embryos has been unknown. In this study, we considered whether (i) the brooding male absorbs the nutrients, (ii) siblings absorb them, or (iii) a combination of both. Males were mated to two sets of females, one of which had radioactively labelled eggs (using 14C-labelled amino acids), such that approximately half the eggs in the brood pouch were labelled. This allowed us to trace nutrient uptake from these embryos. We detected that 14C-labelled amino acids were transferred to the male brood pouch, liver and muscle tissue. However, we did not detect any significant 14C-labelled amino-acid absorption by the non-labelled half-siblings in the brood pouch. Thus, we show, to our knowledge, for the first time, that males absorb nutrients derived from embryos through their paternal brood pouch. PMID:19939847

Hemolymph proteome changes during worker brood development match the biological divergences between western honey bees (Apis mellifera) and eastern honey bees (Apis cerana).

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Feng, Mao; Ramadan, Haitham; Han, Bin; Fang, Yu; Li, Jianke

2014-07-05

Hemolymph plays key roles in honey bee molecule transport, immune defense, and in monitoring the physiological condition. There is a lack of knowledge regarding how the proteome achieves these biological missions for both the western and eastern honey bees (Apis mellifera and Apis cerana). A time-resolved proteome was compared using two-dimensional electrophoresis-based proteomics to reveal the mechanistic differences by analysis of hemolymph proteome changes between the worker bees of two bee species during the larval to pupal stages. The brood body weight of Apis mellifera was significantly heavier than that of Apis cerana at each developmental stage. Significantly, different protein expression patterns and metabolic pathways were observed in 74 proteins (166 spots) that were differentially abundant between the two bee species. The function of hemolymph in energy storage, odor communication, and antioxidation is of equal importance for the western and eastern bees, indicated by the enhanced expression of different protein species. However, stronger expression of protein folding, cytoskeletal and developmental proteins, and more highly activated energy producing pathways in western bees suggests that the different bee species have developed unique strategies to match their specific physiology using hemolymph to deliver nutrients and in immune defense. Our disparate findings constitute a proof-of-concept of molecular details that the ecologically shaped different physiological conditions of different bee species match with the hemolymph proteome during the brood stage. This also provides a starting point for future research on the specific hemolymph proteins or pathways related to the differential phenotypes or physiology.

Varying congruence of hygienic responses to Varroa destructor and freeze-killed brood among different types of honey bees

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Different types of honey bees, Apis mellifera L., have been selectively bred for enhanced hygiene (i.e., removal of affected brood from sealed cells) to improve resistance to diseases and parasites. Bees selected for removal of freeze-killed brood (FKB) have protection from several microbial disease...

Periodical Cicada--Brood V (Pest Alert)

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USDA Forest Service

1999-01-01

Three separate species of periodical cicadas, Magicicada septendecim (L.), M. cassini (Fisher), and M. septendecula (Alexander and Moore), will appear this spring over large portions of Ohio and West Virginia during the scheduled Brood V emergence. This brood is the largest that occurs in either state and was last seen in 1982. It will also emerge in the southwest...

Stingless bees (Melipona subnitida) adjust brood production rather than foraging activity in response to changes in pollen stores.

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Maia-Silva, Camila; Hrncir, Michael; Imperatriz-Fonseca, Vera Lucia; Schorkopf, Dirk Louis P

2016-10-01

Highly eusocial bees (honey bees and stingless bees) sustain their colonies through periods of resource scarcity by food stored within the nest. The protein supply necessary for successful brood production is ensured through adjustments of the colonies' pollen foraging according to the availability of this resource in the environment. In honey bees Apis mellifera, in addition, pollen foraging is regulated through the broods' demand for this resource. Here, we investigated the influence of the colony's pollen store level on pollen foraging and brood production in stingless bees (Melipona subnitida). When pollen was added to the nests, colonies increased their brood production and reduced their pollen foraging within 24 h. On the other hand, when pollen reserves were removed, colonies significantly reduced their brood production. In strong contrast to A. mellifera; however, M. subnitida did not significantly increase its pollen foraging activity under poor pollen store conditions. This difference concerning the regulation of pollen foraging may be due to differences regarding the mechanism of brood provisioning. Honey bees progressively feed young larvae and, consequently, require a constant pollen supply. Stingless bees, by contrast, mass-provision their brood cells and temporary absence of pollen storage will not immediately result in substantial brood loss.

Brood size modifications affect plumage bacterial assemblages of European starlings.

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Lucas, Françoise S; Moureau, Benoit; Jourdie, Violaine; Heeb, Philipp

2005-02-01

During reproduction, birds face trade-offs between time and energy devoted to parental effort and traits associated with self-maintenance. We manipulated brood sizes to investigate the effects of such trade-offs on feather bacterial densities and the structure of bacterial assemblages on feathers in adult European starlings, Sturnus vulgaris, and in vitro feather degradation. As predicted by a trade-off between parental effort and self-maintenance, we found that birds with enlarged broods had more free-living bacteria on their feathers than birds with reduced broods. Furthermore, we found a significant interaction between brood manipulation and original brood size on free-living bacterial densities suggesting that the trade-off is mediated by the adults' initial reproductive investment. In contrast, brood size manipulations had no significant effect on densities of attached bacteria. Using ribosomal intergenic spacer analysis (RISA), we demonstrated that brood manipulations significantly modified the structure (band pattern) of feather-degrading bacterial assemblages, but had no significant effect on their richness (number of bands) or the in vitro feather degradation. In vitro feather degradation varied in relation to the premanipulation brood size and positively with the richness of the feather degrading bacterial community. Besides brood manipulation effect, we found that ecological factors and individual traits, such as the age, the nest location or the capture date, shaped bacterial assemblages and feather degradation capacities.

Assured fitness returns in a social wasp with no worker caste.

Science.gov (United States)

Lucas, Eric R; Field, Jeremy

2011-10-07

The theory of assured fitness returns proposes that individuals nesting in groups gain fitness benefits from effort expended in brood-rearing, even if they die before the young that they have raised reach independence. These benefits, however, require that surviving nest-mates take up the task of rearing these young. It has been suggested that assured fitness returns could have favoured group nesting even at the origin of sociality (that is, in species without a dedicated worker caste). We show that experimentally orphaned brood of the apoid wasp Microstigmus nigrophthalmus continue to be provisioned by surviving adults for at least two weeks after the orphaning. This was the case for brood of both sexes. There was no evidence that naturally orphaned offspring received less food than those that still had mothers in the nest. Assured fitness returns can therefore represent a real benefit to nesting in groups, even in species without a dedicated worker caste.

Brood size and immunity costs in zebra finches Taeniopygia guttata

NARCIS (Netherlands)

Verhulst, S; Riedstra, B; Wiersma, P

Birds rearing experimentally enlarged broods have lower antibody responses to a novel antigen, and we tested three hypotheses that could explain this result. We used zebra finches Taeniopygia guttata inoculated with sheep red blood cells (SRBC) as a study system, for which this trade-off was

Costs and Benefits to Pregnant Male Pipefish Caring for Broods of Different Sizes.

Science.gov (United States)

Sagebakken, Gry; Ahnesjö, Ingrid; Kvarnemo, Charlotta

2016-01-01

Trade-offs between brood size and offspring size, offspring survival, parental condition or parental survival are classic assumptions in life history biology. A reduction in brood size may lessen these costs of care, but offspring mortality can also result in an energetic gain, if parents are able to utilize the nutrients from the demised young. Males of the broad-nosed pipefish (Syngnathus typhle) care for the offspring by brooding embryos in a brood pouch. Brooding males can absorb nutrients that emanate from embryos, and there is often a reduction in offspring number over the brooding period. In this study, using two experimentally determined brood sizes (partially and fully filled brood pouches), we found that full broods resulted in larger number of developing offspring, despite significantly higher absolute and relative embryo mortality, compared to partial broods. Male survival was also affected by brood size, with males caring for full broods having poorer survival, an effect that together with the reduced embryo survival was found to negate the benefit of large broods. We found that embryo mortality was lower when the brooding males were in good initial condition, that embryos in broods with low embryo mortality weighed more, and surprisingly, that males in higher initial condition had embryos of lower weight. Brood size, however, did not affect embryo weight. Male final condition, but not initial condition, correlated with higher male survival. Taken together, our results show costs and benefits of caring for large brood sizes, where the numerical benefits come with costs in terms of both embryo survival and survival of the brooding father, effects that are often mediated via male condition.

Costs and Benefits to Pregnant Male Pipefish Caring for Broods of Different Sizes.

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Gry Sagebakken

Full Text Available Trade-offs between brood size and offspring size, offspring survival, parental condition or parental survival are classic assumptions in life history biology. A reduction in brood size may lessen these costs of care, but offspring mortality can also result in an energetic gain, if parents are able to utilize the nutrients from the demised young. Males of the broad-nosed pipefish (Syngnathus typhle care for the offspring by brooding embryos in a brood pouch. Brooding males can absorb nutrients that emanate from embryos, and there is often a reduction in offspring number over the brooding period. In this study, using two experimentally determined brood sizes (partially and fully filled brood pouches, we found that full broods resulted in larger number of developing offspring, despite significantly higher absolute and relative embryo mortality, compared to partial broods. Male survival was also affected by brood size, with males caring for full broods having poorer survival, an effect that together with the reduced embryo survival was found to negate the benefit of large broods. We found that embryo mortality was lower when the brooding males were in good initial condition, that embryos in broods with low embryo mortality weighed more, and surprisingly, that males in higher initial condition had embryos of lower weight. Brood size, however, did not affect embryo weight. Male final condition, but not initial condition, correlated with higher male survival. Taken together, our results show costs and benefits of caring for large brood sizes, where the numerical benefits come with costs in terms of both embryo survival and survival of the brooding father, effects that are often mediated via male condition.

Current brood size and residual reproductive value predict brood desertion in the burying beetle Nicrophorus vespilloides

OpenAIRE

Ward, R. J. S.; Cotter, S. C.; Kilner, R. M.

2009-01-01

Life-history theory suggests that offspring desertion can be an adaptive reproductive strategy, in which parents forgo the costly care of an unprofitable current brood to save resources for future reproduction. In the burying beetle, Nicrophorus vespilloides, parents commonly abandon their offspring to the care of others, resulting in female-only care, male-only care, brood parasitism, and the care of offspring sired by satellite males. Furthermore, when there is biparental care, males routin...

Movements and habitat use of mallard broods in northeastern California

Science.gov (United States)

Mauser, D.M.; Jarvis, R.L.; Gilmer, D.S.

1994-01-01

To increase recruitment of mallards (Anas platyrhynchos), wildlife managers must understand the habitat and space needs of mallard broods. During 1989-90, we examined the movements, home range, and habitat use of 27 radio-marked mallard broods on Lower Klamath National Wildlife Refuge, California. Twelve of the 27 broods made 22 relocation movements (>1,000 m in 24 hr) in the first week (n = 6) and after the fourth (n = 16) week of life. Mean home range size was 0.93 km2 (SE = 0.25) and did not differ between years (P = 0.26). Brood-rearing females selected seasonally flooded wetlands with a cover component and avoided open or permanently flooded habitats. In 1989, broods hatched in permanent wetlands were less successful in fledging (P = 0.006) radio-marked ducklings than broods from seasonal wetlands, suggesting habitat availability or movement to preferred habitats may affect duckling survival.

Egg size matching by an intraspecific brood parasite

Science.gov (United States)

Lemons, Patrick R.; Sedinger, James S.

2011-01-01

Avian brood parasitism provides an ideal system with which to understand animal recognition and its affect on fitness. This phenomenon of laying eggs in the nests of other individuals has classically been framed from the perspective of interspecific brood parasitism and host recognition of parasitic eggs. Few examples exist of strategies adopted by intraspecific brood parasites to maximize success of parasitic eggs. Intraspecific brood parasitism within precocial birds can be a risky strategy in that hatch synchrony is essential to reproductive success. Given that egg size is positively correlated with incubation time, parasitic birds would benefit by recognizing and selecting hosts with a similar egg size. Intraspecific brood parasitism is an alternative reproductive strategy in black brant (Branta bernicla nigricans), a colonial nesting goose with precocial young. Based on a randomization test, parasitic eggs in this study differed less in size from eggs in their host's nests than did random eggs placed in random nests. Parasitic eggs were remarkably similar in size to hosts’ eggs, differing by nests differed by nearly 8%. The precision with which parasitic brant match the egg size of hosts in our study supports our hypothesis that brant match egg size of hosts, thereby maximizing hatching success of their parasitic eggs.

Social interactions and their connection to aggression and ovarian development in orphaned worker bumblebees (Bombus impatiens).

Science.gov (United States)

Sibbald, E D; Plowright, C M S

2014-03-01

This study examines the social dynamics of reproductive conflict. Orphaned worker bumblebees (Bombus impatiens) with comparatively high or low levels of social activity were paired to determine whether aggression and reproduction could be traced to earlier social interactions. The workers were paired according to their levels of social activity (a socially active+another socially active worker, socially active+socially inactive, and two socially inactive workers). The presence or absence of brood was also manipulated. The absence of brood increased both aggression and ovarian development, suggesting that aggression and reproduction are associated or that there is a third variable that affects both. Socially active pairs were significantly more aggressive: here, social activity can be taken as an early indicator of aggression. No such effect, however, was obtained on ovarian development as the socially active pairs did not differ on their degree of ovarian development compared to the others. Within the socially active+socially inactive pairs, the socially active worker did not have more developed ovaries and was not more aggressive than her socially inactive partner. Results highlight that environmental conditions (the absence of brood) can predict ovarian development and although social activity can be observed prior to aggression, differences in aggression do not translate into differences in ovarian development under these conditions. Copyright © 2013 Elsevier B.V. All rights reserved.

Behaviour patterns of Mallard Anas Platyrhynchos pairs and broods in Minnesota and North Dakota

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Pietz, P.J.; Buhl, D.A.

1999-01-01

Few studies have quantitatively examined Mallard behaviour in North America during the breeding season. We estimated diurnal time budgets of unmarked Mallard males, females, and broods from over 1,200 hours of observations at two study areas in western Minnesota and south-central North Dakota during 1988-91. Paired males spent less time feeding and more time alert than did females. Both pair members were engaged in the same behaviour about 67% of the time; the male was always most likely to be doing the same thing as the female, but when the male was resting on water or alert, the female was most likely to be feeding. Females with broods spent less time feeding and more time alert and in locomotion than did females without broods. Behaviour of brood females did not differ with brood age or size. Females temporarily left their broods alone 45 times - about once for each 11 hours of observation. Female absences ranged from 2 to >80 minutes (x>27 min); length of absence was not related to brood age or size. Broods of all ages (a few days old to near fledging) and sizes (1-10 ducklings) were left alone on land and water; broods mostly rested and fed during female absences. Brood females spent less time feeding and more time alert than did broods. Females and their broods were engaged in the same behaviour 6267% of the time; the female was always most likely to be doing the same behaviour as her brood, but when the female was resting on water, the brood was most likely to be feeding, and when the female was alert, the brood was most likely to be feeding (North Dakota site) or resting on land (Minnesota site). Daily activity patterns varied between sites for both pairs and broods. Feeding and resting behaviour showed opposite daily patterns, suggesting that time allocated to feeding constrained time spent resting. Differences between sites and years in time spent feeding by pairs and broods probably reflected varying water conditions and food availability. In light of

Pollen types used by Centris (Hemisiella tarsata Smith (1874 (Hymenoptera, Apidae in the provisioning of brood cells in an area of Caatinga

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Ana Paula Araújo da Cruz

2015-06-01

Full Text Available The aim of this study was to identify, by sediment pollen analysis, the plant species used as floral resources for the provisioning of brood cells in Centris (Hemisiella tarsata, in an area of Caatinga, within the municipality of Nova Soure, Bahia State, Brazil. The analysis of pollen contents from three brood cells revealed 11 pollen types, corresponding to four botanical families. Malpighiaceae was represented most, followed by Leguminosae, Ochnaceae, and Solanaceae, the latter two represented by just a single pollen type each. On the basis of the percentages in the samples, it was possible to infer that C. tarsata visited distinct plants, but intensified its pollen collection in species related to Aeschynomene martii and Solanum paniculatumpollen types, which are considered the most important pollen sources in the larval diet of this bee. In addition to the pollen sources, we have also recorded seven pollen types regarded as oil ones, all related to the Malpighiaceae family. The information about the resources for C. tarsata can be of great relevance, in view of the importance of these bees in the pollination of native flora.

Begging and cowbirds : brood parasites make hosts scream louder

NARCIS (Netherlands)

Boncoraglio, Giuseppe; Saino, Nicola; Garamszegi, Laszlo Z.

2009-01-01

Avian brood parasites have evolved striking begging ability that often allows them to prevail over the host progeny in competition for parental resources. Host young are therefore selected by brood parasites to evolve behavioral strategies that reduce the cost of parasitism. We tested the prediction

Tricks of the trade: Mechanism of brood theft in an ant.

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Paul, Bishwarup; Annagiri, Sumana

2018-01-01

Thievery is ubiquitous in the animal kingdom, social insects not being an exception. Brood is invaluable for the survival of social insect colonies and brood theft is well documented in ants. In many species the stolen brood act as slaves in the thief colony as they take up tasks related to foraging, defence and colony maintenance. Slave-making (dulotic) ants are at an advantage as they gain workforce without investing in rearing immature young, and several slave-making species have been recorded in temperate regions. In the current study we investigate brood theft in a primitively eusocial ponerine ant Diacamma indicum that inhabits the tropics. In the context of colony relocation we asked how thieves steal brood and what victim colonies do to prevent theft. While exposed nests increased colonies' vulnerability, the relocation process itself did not enhance the chances of theft. Various aggressive interactions, in particular immobilization of intruders helped in preventing theft. Thieves that acted quickly, stayed furtive and stole unguarded brood were found to be successful. This comprehensive study of behavioural mechanism of theft reveals that these are the 'tricks' adopted by thieves.

Does the removal of mite-infested brood facilitate grooming?

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The relationship between the removal of mite-infested brood and mite drop was compared using Russian (RHB, n = 9) and Italian (IHB, n = 9) honey bee colonies. A cloake board was used to isolate test brood frame on the top hive body and the metal sheet served as a varroa trap. Inoculum mites were col...

Social learning of a brood parasite by its host

Science.gov (United States)

Feeney, William E.; Langmore, Naomi E.

2013-01-01

Arms races between brood parasites and their hosts provide model systems for studying the evolutionary repercussions of species interactions. However, how naive hosts identify brood parasites as enemies remains poorly understood, despite its ecological and evolutionary significance. Here, we investigate whether young, cuckoo-naive superb fairy-wrens, Malurus cyaneus, can learn to recognize cuckoos as a threat through social transmission of information. Naive individuals were initially unresponsive to a cuckoo specimen, but after observing conspecifics mob a cuckoo, they made more whining and mobbing alarm calls, and spent more time physically mobbing the cuckoo. This is the first direct evidence that naive hosts can learn to identify brood parasites as enemies via social learning. PMID:23760171

Brood size and its importance for nestling growth in the Biscutate Swift (Streptoprocne biscutata, Aves: Apodidae

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M. Pichorim

Full Text Available Many Apodidae, including Streptoprocne biscutata (Sclater, 1866, drop eggs from their nests during incubation. This is interpreted as nest site competition or accident. We provide evidence that egg ejection is deliberate and that this behaviour controls the brood size. Brood sizes were manipulated and nestling growth was measured to test the hypothesis that pairs can regulate brood size during incubation based on current ability to rear nestlings. Natural (control broods with one, two and three nestlings, and manipulated (experimental broods reduced to one and increased to two and three young were monitored. Growth rates were measured based on weight, and wing, tail and tarsus lengths of natural and manipulated broods. We compared the slopes of each measure's regression lines of the nestlings of each brood size by t-test. Nestling growth of control nests was similar and relatively little associated with brood size. In broods reduced to one nestling, weight, wing and tail had greater growth rates, and in broods increased to three nestlings growth rates were lower. Weight was most, and tarsus length least influenced by brood size. In general, nestling growth of manipulated nests was inversely proportional to brood size. The results suggest that pairs with larger clutches are in better physical conditions than others. Thus, in experimental broods, pairs are over or under-loaded because feeding activities increase or decrease and these changes affect the growth rate of the nestlings. The present study suggests that egg ejection can control brood size. This behaviour is probably stimulated by physical changes in the adult birds during incubation.

Using sightability-adjusted brood-pair ratios to estimate waterfowl productivity

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Pagano, Anthony M.; Amundson, Courtney L.; Pieron, Matthew R.; Arnold, Todd W.; Kimmel, Timothy C.

2014-01-01

Historically, biologists used brood-pair ratios (BPRs) as an index to waterfowl productivity to help guide management decisions and evaluate conservation practices. However, BPRs are biased by imperfect detection probabilities, especially for broods. We conducted roadside surveys for breeding waterfowl pairs on 7–8 study sites in the springs of 2006–2008 in northeastern North Dakota, USA. Later each year, we conducted replicate counts of broods on the same wetlands and used mark–recapture methods to estimate sightability-adjusted BPRs (SA-BPRs). Traditional roadside brood surveys detected only 30–45% of the available broods, depending on species. We explored the potential for using SA-BPRs to measure hen success (i.e., the probability a female hatches ≥1 egg across all nesting attempts) for mallards (Anas platyrhynchos) and other upland-nesting dabbling ducks (Anas spp.). We found that SA-BPRs explained 40% of the variation in hen success over 5 species of dabbling ducks, and we were able to detect an effect of predator reduction on hen success in combined dabblers, but not in mallards alone. However, we found no relationship between SA-BPRs and mallard fledging rates (hen success × initial brood size × duckling survival). Our results suggest that SA-BPRs can provide a cost-effective alternative to traditional measures of productivity such as nesting success, but not to measures of duckling survival. Nevertheless, SA-BPRs may be useful in areas where traditional measures of waterfowl productivity are logistically or financially challenging.

Repression and recuperation of brood production in Bombus terrestris bumble bees exposed to a pulse of the neonicotinoid pesticide imidacloprid.

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Ian Laycock

Full Text Available Currently, there is concern about declining bee populations and some blame the residues of neonicotinoid pesticides in the nectar and pollen of treated crops. Bumble bees are important wild pollinators that are widely exposed to dietary neonicotinoids by foraging in agricultural environments. In the laboratory, we tested the effect of a pulsed exposure (14 days 'on dose' followed by 14 days 'off dose' to a common neonicotinoid, imidacloprid, on the amount of brood (number of eggs and larvae produced by Bombus terrestris L. bumble bees in small, standardised experimental colonies (a queen and four adult workers. During the initial 'on dose' period we observed a dose-dependent repression of brood production in colonies, with productivity decreasing as dosage increased up to 98 µg kg(-1 dietary imidacloprid. During the following 'off dose' period, colonies showed a dose-dependent recuperation such that total brood production during the 28-day pulsed exposure was not correlated with imidacloprid up to 98 µg kg(-1. Our findings raise further concern about the threat to wild bumble bees from neonicotinoids, but they also indicate some resilience to a pulsed exposure, such as that arising from the transient bloom of a treated mass-flowering crop.

Repression and Recuperation of Brood Production in Bombus terrestris Bumble Bees Exposed to a Pulse of the Neonicotinoid Pesticide Imidacloprid

Science.gov (United States)

Laycock, Ian; Cresswell, James E.

2013-01-01

Currently, there is concern about declining bee populations and some blame the residues of neonicotinoid pesticides in the nectar and pollen of treated crops. Bumble bees are important wild pollinators that are widely exposed to dietary neonicotinoids by foraging in agricultural environments. In the laboratory, we tested the effect of a pulsed exposure (14 days ‘on dose’ followed by 14 days ‘off dose’) to a common neonicotinoid, imidacloprid, on the amount of brood (number of eggs and larvae) produced by Bombus terrestris L. bumble bees in small, standardised experimental colonies (a queen and four adult workers). During the initial ‘on dose’ period we observed a dose-dependent repression of brood production in colonies, with productivity decreasing as dosage increased up to 98 µg kg−1 dietary imidacloprid. During the following ‘off dose’ period, colonies showed a dose-dependent recuperation such that total brood production during the 28-day pulsed exposure was not correlated with imidacloprid up to 98 µg kg−1. Our findings raise further concern about the threat to wild bumble bees from neonicotinoids, but they also indicate some resilience to a pulsed exposure, such as that arising from the transient bloom of a treated mass-flowering crop. PMID:24224015

Morphology of brood pouch formation in the pot-bellied seahorse Hippocampus abdominalis.

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Kawaguchi, Mari; Okubo, Ryohei; Harada, Akari; Miyasaka, Kazuki; Takada, Kensuke; Hiroi, Junya; Yasumasu, Shigeki

2017-01-01

The reproductive strategies of vertebrates are diverse. Seahorses (Pisces: Syngnathidae) possess the unique characteristic of male pregnancy; i.e., males, not females, incubate embryos in a specialized structure called a 'brood pouch'. The brood pouch is formed along the ventral midline of the tail. The lumen of the brood pouch is surrounded by loose connective tissue, called pseudoplacenta, and dermis. We visualized and evaluated the morphology of brood pouch formation in Hippocampus abdominalis to gain generalizable insights into this process in seahorses. First, we employed several staining methods to characterize the pseudoplacenta and dermis of the brood pouch of mature male seahorses. The pseudoplacenta is composed mainly of reticular fibers, while the dermis is composed mainly of collagenous fibers. Further observations showed that pouch formation is initiated by linear projections of epithelia on both ventrolateral sides of the body. These projections elongated toward the ventral midline, eventually fused together, and then formed a baggy structure composed of a single dermis layer with neither smooth muscle nor pseudoplacenta. Finally, the pseudoplacenta was formed, together with two layers of dermis and smooth muscle. Thus, a fully developed brood pouch was established. The morphology of the luminal epithelium also changed during pouch formation. We analyzed the localization of C-type lectins as markers; haCTL II was localized in both the outer and luminal epithelia of the brood pouch throughout development in the male seahorse, whereas haCTL IV, which was not detected in the early stage of seahorse development, became localized only in the luminal epithelium as development proceeded. We categorized the processes of brood pouch formation during male seahorse development into three stages: (1) the early stage, characterized by formation of a baggy structure from the primordium; (2) the middle stage, characterized by the differentiation and establishment of

Drone brood production in Danish apiaries and its potential for human consumption

DEFF Research Database (Denmark)

Lecocq, Antoine; Foley, Kirsten; Jensen, Annette Bruun

2018-01-01

Current evidence indicates that the practice of drone brood removal is an effective measure of varroa mite control when combined with chemical treatment as part of an Integrated Pest Management strategy. This has led to a widespread adoption of the method in Denmark and other European countries....... Recently, there has been growing interest in the value of insects as a sustainable and highly nutritious food item. To examine the potential use of drone brood as a food source on a commercial scale, we gathered data from nine Danish apiaries. The weight of drone brood comb removed from each colony...... was recorded and from one apiary, the edible biomass was determined. The total weight of the drone brood comb removed from each colony over the season was highly variable ranging from 0.184 kg to 4.035 kg with an average of 1.776 kg and the average total drone brood biomass extracted was 1.064 kg per colony...

Variation in selection of microhabitats by Merriam's turkey brood hens

Science.gov (United States)

Mark A. Rumble; Stanley H. Anderson

1997-01-01

We studied microhabitats of Merriam‘s turkey (Meleagris gallopavo merriami) brood hens in a ponderosa pine (Pinus ponderosa) ecosystem in South Dakota from 1986 to 1988. Cluster analysis indicated three groups of microhabitats, open-shrub, open-grasslforb and forest, based on vegetation characteristics at sites selected by brood...

Sexual imprinting misguides species recognition in a facultative interspecific brood parasite.

Science.gov (United States)

Sorenson, Michael D; Hauber, Mark E; Derrickson, Scott R

2010-10-22

Sexual reproduction relies on the recognition of conspecifics for breeding. Most experiments in birds have implicated a critical role for early social learning in directing subsequent courtship behaviours and mating decisions. This classical view of avian sexual imprinting is challenged, however, by studies of megapodes and obligate brood parasites, species in which reliable recognition is achieved despite the lack of early experience with conspecifics. By rearing males with either conspecific or heterospecific brood mates, we experimentally tested the effect of early social experience on the association preferences and courtship behaviours of two sympatrically breeding ducks. We predicted that redheads (Aythya americana), which are facultative interspecific brood parasites, would show a diminished effect of early social environment on subsequent courtship preferences when compared with their host and congener, the canvasback (Aythya valisineria). Contrary to expectations, cross-fostered males of both species courted heterospecific females and preferred them in spatial association tests, whereas control males courted and associated with conspecific females. These results imply that ontogenetic constraints on species recognition may be a general impediment to the initial evolution of interspecific brood parasitism in birds. Under more natural conditions, a variety of mechanisms may mitigate or counteract the effects of early imprinting for redheads reared in canvasback broods.

Ecological factors regulating brood attendance patterns of the western sandpiper calidris mauri

Science.gov (United States)

Ruthrauff, D.R.; Keller, J.N.; Rizzolo, D.J.

2009-01-01

Parental brood attendance patterns vary greatly among shorebird species. For monogamous calidridine species, biparental care with female-first brood departure is most common. It is believed that adult sandpipers balance potential individual survival costs associated with extended parental care against the benefit gained by their brood of prolonged parental care. These costs and benefits are difficult to quantify and factors affecting the termination of parental brood attendance are unclear. We compared clutch size, nesting phenology, and parental attendance patterns of Western Sandpipers Calidris mauri at Nome and Kanaryarmiut, Alaska, sites separated by three degrees of latitude. The sites differed in breeding density and duration of breeding season, but the distribution of clutch sizes did not differ between sites or between nesting attempts. Parental attendance patterns were similar between sites, suggesting that parental attendance is a highly conserved life-history trait in Western Sandpipers. Male Western Sandpipers attended broods longer than females, and the duration of parental attendance decreased at a similar rate for both sexes as the season progressed. Male and female Western Sandpipers undertake differential migrations to their non-breeding grounds, with males typically settling at more northerly locations and females at more southerly sites, a migration pattern shared by certain other monogamous calidridine species. These same species exhibit similar parental brood attendance patterns, suggesting the strong role of overall migration distance in shaping the expression of parental attendance behaviours. A contrast of more geographically disjunct sites coupled with a better understanding of the migratory connectivity between Western Sandpiper breeding and non-breeding populations would elucidate the role of cross-seasonal effects on parental brood attendance decisions. ?? 2009 British Ornithologists' Union.

Hygienic behavior in the stingless bees Melipona beecheii and Scaptotrigona pectoralis (Hymenoptera: Meliponini).

Science.gov (United States)

Medina, L M; Hart, A G; Ratnieks, F L W

2009-05-19

Hygienic behavior, a trait that may confer resistance to brood diseases in the honey bee Apis mellifera, was studied in two species of stingless bees in Mexico. Eight colonies each of Melipona beecheii and Scaptotrigona pectoralis were tested for hygienic behavior, the removal of dead or diseased brood, by freeze killing a comb of sealed cells containing pupae. Both species detected and removed dead brood. However, removal rates differed between species. In M. beecheii colonies, workers took 2-9 days to remove 100% of the dead brood (4.4 +/- 2.0 days, mean +/- SD), while S. pectoralis removed all dead brood in less than 3 days (2.3 +/- 0.6 days, mean +/- SD). We conclude that hygienic behavior is not unique to A. mellifera, and is not solely an adaptation for the reuse of brood cells as occurs in honey bees but not stingless bees. Although stingless bees do not reuse brood cells, space is limited. The removal of dead brood may be necessary to allow new cells to be constructed in the same place.

Mitochondrial DNA variation in brood stocks of the lake trout

International Nuclear Information System (INIS)

Grewe, P.M.; Hebert, P.D.N.

1986-01-01

Efforts are in progress to restore lake trout populations in the Great Lakes from hatchery stocks. In most cases, plantings include a variety of brood stocks that originated from different portions of the Great Lakes. Members of the various stocks can be differentially fin clipped to permit comparison of their survival success, but this does not allow assessment of their reproductive capability in the wild. Assessment of reproductive success requires the existence of genetic markers between brook stocks which will ideally persist over many generations. Efforts to identify allozyme differences between brood stocks have met with little success. The present investigation has employed an alternative technique to identify genetic markers--the restriction analysis of mitochondrial DNA. Mitochondiral DNA analysis of 7 lake trout brood stocks has revealed the existence of 10 mitochondrial clones falling into 3 major groups. The results indicate that mt-DNA markers have great potential for brood stock management. Genetic variability in the nuclear genome of each stock can be maintained by utilizing a large number of male parents, while restricting female parents to members of a single mitochondrial clone. Genetically marked fry could then be produced with only minor shifts in hatchery management

Mobbing and sitting tight at the nest as methods of avoiding brood parasitism.

Science.gov (United States)

Rands, Sean A

2012-04-06

The arms race between brood parasites and their hosts has led to many different host behaviours for avoiding parasitism. Some of these behaviours are social, and require the presence of conspecifics to work effectively: in response to alarm calls, some species engage in mobbing behaviour where neighbours join nest tenants in attacking and repelling an invading brood parasite. There are risks involved for the neighbours, but it has been demonstrated that social mobbing allows individuals to learn about the presence of brood parasites in the environment, suggesting that social learning is occurring. Here, I consider whether using social signals to alert naive individuals to the presence of brood parasites is a suitable strategy, compared with sitting tight on the nest in response to the signal (which should reduce the chances of being parasitized). I also compare the efficiency of these strategies with the case where individuals fail to change behaviour in response a brood parasite. Using an individual-based simulation model, I demonstrate that both mobbing and sitting tight are effective strategies in response to a signal, and that mobbing is more effective when the chances of being parasitized increase. These results are discussed and compared with known host-brood parasite relationships.

Karyotype and C-banding analyses of haploid male chromosomes ...

African Journals Online (AJOL)

Prior to the swarming season, drone-brood cells were added adjoining to the lower rows of the worker-brood cells. Testes from young larvae were removed, fixed in acetic acid methanol (1:3), and stored at -20°C. The slides pretreatment were made by usual air dry method. C-banding and staining was carried out by barium ...

Community Health Workers as Support for Sickle Cell Care

Science.gov (United States)

Hsu, Lewis L.; Green, Nancy S.; Ivy, E. Donnell; Neunert, Cindy; Smaldone, Arlene; Johnson, Shirley; Castillo, Sheila; Castillo, Amparo; Thompson, Trevor; Hampton, Kisha; Strouse, John J.; Stewart, Rosalyn; Hughes, TaLana; Banks, Sonja; Smith-Whitley, Kim; King, Allison; Brown, Mary; Ohene-Frempong, Kwaku; Smith, Wally R.; Martin, Molly

2016-01-01

Community health workers are increasingly recognized as useful for improving health care and health outcomes for a variety of chronic conditions. Community health workers can provide social support, navigation of health systems and resources, and lay counseling. Social and cultural alignment of community health workers with the population they serve is an important aspect of community health worker intervention. Although community health worker interventions have been shown to improve patient-centered outcomes in underserved communities, these interventions have not been evaluated with sickle cell disease. Evidence from other disease areas suggests that community health worker intervention also would be effective for these patients. Sickle cell disease is complex, with a range of barriers to multifaceted care needs at the individual, family/friend, clinical organization, and community levels. Care delivery is complicated by disparities in health care: access, delivery, services, and cultural mismatches between providers and families. Current practices inadequately address or provide incomplete control of symptoms, especially pain, resulting in decreased quality of life and high medical expense. The authors propose that care and care outcomes for people with sickle cell disease could be improved through community health worker case management, social support, and health system navigation. This report outlines implementation strategies in current use to test community health workers for sickle cell disease management in a variety of settings. National medical and advocacy efforts to develop the community health workforce for sickle cell disease management may enhance the progress and development of “best practices” for this area of community-based care. PMID:27320471

Atlantic salmon brood stock management and breeding handbook

Science.gov (United States)

Kincaid, Harold L.; Stanley, Jon G.

1989-01-01

Anadromus runs of Atlantic salmon have been restored to the Connecticut, Merrimack, Pawcatuck, Penobscot, and St. Croix rivers in New England by the stocking of more than 8 million smolts since 1948. Fish-breeding methods have been developed that minimize inbreeding and domestication and enhance natural selection. Methods are available to advance the maturation of brood stock, control the sex of production lots and store gametes. Current hatchery practices emphasize the use of sea-run brood stock trapped upon return to the rivers and a limited number of captive brood stock and rejuvenated kelts. Fish are allowed to mature naturally, after which they are spawned and incubated artificially. Generally, 1-year smolts are produced, and excess fish are stocked as fry in headwater streams. Smolts are stocked during periods of rising water in spring. Self-release pools are planned that enable smolts to choose the emigration time. Culturists keep good records that permit evaluation of the performance of strains and the effects of breeding practices. As Atlantic salmon populations expand, culturists must use sound breeding methods that enhance biotic potential while maintaining genetic diversity and protecting unique gene pools.

Brooding in the Chilean oyster Ostrea chilensis: unexpected complexity in the movements of brooded offspring within the mantle cavity.

Science.gov (United States)

Mardones-Toledo, Daniela A; Montory, Jaime A; Joyce, Alyssa; Thompson, Raymond J; Diederich, Casey M; Pechenik, Jan A; Mardones, Maria L; Chaparro, Oscar R

2015-01-01

Brooding in invertebrates serves to protect embryos from stressful external conditions by retaining progeny inside the female body, effectively reducing the risk of pelagic stages being exposed to predation or other environmental stressors, but with accompanying changes in pallial fluid characteristics, including reduced oxygen availability. Brooded embryos are usually immobile and often encapsulated, but in some Ostrea species the embryos move freely inside the female pallial cavity in close association with the mother's gills for as long as eight weeks. We used endoscopic techniques to characterize the circulation pattern of embryos brooded by females of the oyster, Ostrea chilensis. Progeny at embryonic and veliger stages typically circulated in established patterns that included the use of dorsal and ventral food grooves (DFG, VFG) to move anteriorly on the gills. Both embryos and veligers accumulated around the mother's palps, and remained there until an active maternal countercurrent moved them to the gill inhalant area. Both food grooves were able to move embryos, veligers, and food-particle aggregates anteriorly, but the DFG was more important in progeny transport; early embryos were moved more rapidly than veligers in the DFG. A microcirculation pattern of embryos was apparent when they were moved by gill lamellae: when they were close to the VFG, most embryos lost gill contact and "fell" down to the DFG. Those that actually reached the DFG moved anteriorly, but others came into contact with the base of the lamellae and again moved towards the VFG. The circulation pattern of the progeny appears well-suited for both cleaning them and directing them posteriorly to an area where there is more oxygen and food than in the palp region. This process for actively circulating progeny involves the feeding structures (gill and palps) and appears to be energetically costly for the female. It also interferes with feeding, which could explain the poor energy balance

Brooding in the Chilean oyster Ostrea chilensis: unexpected complexity in the movements of brooded offspring within the mantle cavity.

Directory of Open Access Journals (Sweden)

Daniela A Mardones-Toledo

Full Text Available Brooding in invertebrates serves to protect embryos from stressful external conditions by retaining progeny inside the female body, effectively reducing the risk of pelagic stages being exposed to predation or other environmental stressors, but with accompanying changes in pallial fluid characteristics, including reduced oxygen availability. Brooded embryos are usually immobile and often encapsulated, but in some Ostrea species the embryos move freely inside the female pallial cavity in close association with the mother's gills for as long as eight weeks. We used endoscopic techniques to characterize the circulation pattern of embryos brooded by females of the oyster, Ostrea chilensis. Progeny at embryonic and veliger stages typically circulated in established patterns that included the use of dorsal and ventral food grooves (DFG, VFG to move anteriorly on the gills. Both embryos and veligers accumulated around the mother's palps, and remained there until an active maternal countercurrent moved them to the gill inhalant area. Both food grooves were able to move embryos, veligers, and food-particle aggregates anteriorly, but the DFG was more important in progeny transport; early embryos were moved more rapidly than veligers in the DFG. A microcirculation pattern of embryos was apparent when they were moved by gill lamellae: when they were close to the VFG, most embryos lost gill contact and "fell" down to the DFG. Those that actually reached the DFG moved anteriorly, but others came into contact with the base of the lamellae and again moved towards the VFG. The circulation pattern of the progeny appears well-suited for both cleaning them and directing them posteriorly to an area where there is more oxygen and food than in the palp region. This process for actively circulating progeny involves the feeding structures (gill and palps and appears to be energetically costly for the female. It also interferes with feeding, which could explain the poor

Assessing Greater Sage-Grouse Selection of Brood-Rearing Habitat Using Remotely-Sensed Imagery: Can Readily Available High-Resolution Imagery Be Used to Identify Brood-Rearing Habitat Across a Broad Landscape?

Science.gov (United States)

Westover, Matthew; Baxter, Jared; Baxter, Rick; Day, Casey; Jensen, Ryan; Petersen, Steve; Larsen, Randy

2016-01-01

Greater sage-grouse populations have decreased steadily since European settlement in western North America. Reduced availability of brood-rearing habitat has been identified as a limiting factor for many populations. We used radio-telemetry to acquire locations of sage-grouse broods from 1998 to 2012 in Strawberry Valley, Utah. Using these locations and remotely-sensed NAIP (National Agricultural Imagery Program) imagery, we 1) determined which characteristics of brood-rearing habitat could be used in widely available, high resolution imagery 2) assessed the spatial extent at which sage-grouse selected brood-rearing habitat, and 3) created a predictive habitat model to identify areas of preferred brood-rearing habitat. We used AIC model selection to evaluate support for a list of variables derived from remotely-sensed imagery. We examined the relationship of these explanatory variables at three spatial extents (45, 200, and 795 meter radii). Our top model included 10 variables (percent shrub, percent grass, percent tree, percent paved road, percent riparian, meters of sage/tree edge, meters of riparian/tree edge, distance to tree, distance to transmission lines, and distance to permanent structures). Variables from each spatial extent were represented in our top model with the majority being associated with the larger (795 meter) spatial extent. When applied to our study area, our top model predicted 75% of naïve brood locations suggesting reasonable success using this method and widely available NAIP imagery. We encourage application of our methodology to other sage-grouse populations and species of conservation concern.

Costs of reproduction in the Zebra Finch Taeniopygia guttata : Manipulation of brood size in the laboratory

NARCIS (Netherlands)

deKogel, CH; Overkamp, GFJ

1996-01-01

Brood size of Zebra Finches Taeniopygia guttata was manipulated in an attempt to identify a trade-off between current and subsequent reproduction in a laboratory situation with ad libitum food availability. The birds were able to raise a larger brood than the most frequent brood size under the same

Influence of behavior and mating success on brood-specific contribution to fish recruitment in ponds.

Science.gov (United States)

Parkos, Joseph J; Wahl, David H; Philipp, David P

2011-10-01

One source of uncertainty in predicting the response of populations to exploitation is individual differences within a population in both vulnerability to capture and contribution to population renewal. For species with parental care, individuals engaged in nesting behavior are often targeted for exploitation, but predicting outcomes of this nonrandom vulnerability will depend in part on an understanding of how parental traits are related to potential for brood contribution to the population. Variation in brood-specific contribution to recruitment of largemouth bass (Micropterus salmoides), a fish species with extended parental care, was quantified to determine if differences in mating success, parental care behaviors, and timing of reproduction influenced offspring recruitment. Dependence of these relationships on brood predation was tested in communities that differed in the presence of bluegill, Lepomis macrochirus, an important nest predator. Daily snorkel surveys were conducted in experimental ponds during spring to monitor male spawning and parental care behaviors in populations of largemouth bass. Tissue samples collected from larvae in nests were used to develop brood-specific DNA fingerprints for determining nest origins of fall recruits. Largemouth bass spawning period in bluegill ponds was longer and more variable in duration, with lower, more variable mating success, than in ponds without bluegill. In all populations, only one or two broods provided the majority of recruits, and these were broods produced during the earliest days of spawning by the oldest, largest males. In bluegill ponds, brood contribution from earliest nests also increased with brood size. Earliest nesters were the oldest males, and recruits from these nests were often above average in body size. Offspring needed to be guarded to at least swim-up larval stage to contribute any recruits. Termination of parental protection before offspring were free swimming mainly occurred with broods

Nest destruction elicits indiscriminate con- versus heterospecific brood parasitism in a captive bird.

Science.gov (United States)

Shaw, Rachael C; Feeney, William E; Hauber, Mark E

2014-12-01

Following nest destruction, the laying of physiologically committed eggs (eggs that are ovulated, yolked, and making their way through the oviduct) in the nests of other birds is considered a viable pathway for the evolution of obligate interspecific brood parasitism. While intraspecific brood parasitism in response to nest predation has been experimentally demonstrated, this pathway has yet to be evaluated in an interspecific context. We studied patterns of egg laying following experimental nest destruction in captive zebra finches, Taeniopygia guttata, a frequent intraspecific brood parasite. We found that zebra finches laid physiologically committed eggs indiscriminately between nests containing conspecific eggs and nests containing heterospecific eggs (of Bengalese finches, Lonchura striata vars. domestica), despite the con- and heterospecific eggs differing in both size and coloration. This is the first experimental evidence that nest destruction may provide a pathway for the evolution of interspecific brood parasitism in birds.

Duckling survival, fecundity, and habitat selection of mottled duck broods on the upper Texas Gulf Coast

Science.gov (United States)

Rigby, Elizabeth A.; Haukos, David A.

2015-01-01

Mottled ducks (Anas fulvigula) on the western Gulf Coast have exhibited a steep population decline since the mid 1990s. Low rates of breeding incidence and nest success have been implicated in this decline, but duckling survival and the habitat needs of broods have not been previously investigated in this region. We fitted mottled duck ducklings and adult females with radio transmitters and tracked broods to estimate duckling survival and brood habitat selection on the upper Texas Gulf Coast. Duckling survival to 30 days was high (range among models 0.354–0.567) compared to other dabbling duck species. Estimated fecundity was low, (range among models 0.398–0.634) however, indicating that overall reproductive output is low. Within coastal marsh, broods selected home ranges with more water cover and less upland and fresh marsh landcover than was available in the study area. Within coastal marsh home ranges, broods selected for water cover relative to other landcover types, and there was some evidence that broods avoided unvegetated landcover. Although high quality brood habitat is undeniably important, management efforts to increase mottled duck population growth on the western Gulf Coast may best be spent on increasing nesting habitat quality to increase nest success and breeding incidence.

Notch signalling mediates reproductive constraint in the adult worker honeybee

Science.gov (United States)

Duncan, Elizabeth J.; Hyink, Otto; Dearden, Peter K.

2016-01-01

The hallmark of eusociality is the reproductive division of labour, in which one female caste reproduces, while reproduction is constrained in the subordinate caste. In adult worker honeybees (Apis mellifera) reproductive constraint is conditional: in the absence of the queen and brood, adult worker honeybees activate their ovaries and lay haploid male eggs. Here, we demonstrate that chemical inhibition of Notch signalling can overcome the repressive effect of queen pheromone and promote ovary activity in adult worker honeybees. We show that Notch signalling acts on the earliest stages of oogenesis and that the removal of the queen corresponds with a loss of Notch protein in the germarium. We conclude that the ancient and pleiotropic Notch signalling pathway has been co-opted into constraining reproduction in worker honeybees and we provide the first molecular mechanism directly linking ovary activity in adult worker bees with the presence of the queen. PMID:27485026

Brooding Rumination and Risk for Depressive Disorders in Children of Depressed Mothers

Science.gov (United States)

Gibb, Brandon E.; Grassia, Marie; Stone, Lindsey B.; Uhrlass, Dorothy J.; McGeary, John E.

2012-01-01

The goal of the current study was to examine the role of brooding rumination in children at risk for depression. We found that children of mothers with a history of major depression exhibited higher levels of brooding rumination than did children of mothers with no depression history. Examining potential mechanisms of this risk, we found no…

Proteomic analysis in the Dufour's gland of Africanized Apis mellifera workers (Hymenoptera: Apidae.

Directory of Open Access Journals (Sweden)

Aparecida das Dores Teixeira

Full Text Available The colony of eusocial bee Apis mellifera has a reproductive queen and sterile workers performing tasks such as brood care and foraging. Chemical communication plays a crucial role in the maintenance of sociability in bees with many compounds released by the exocrine glands. The Dufour's gland is a non-paired gland associated with the sting apparatus with important functions in the communication between members of the colony, releasing volatile chemicals that influence workers roles and tasks. However, the protein content in this gland is not well studied. This study identified differentially expressed proteins in the Dufour's glands of nurse and forager workers of A. mellifera through 2D-gel electrophoresis and mass spectrometry. A total of 131 spots showed different expression between nurse and forager bees, and 28 proteins were identified. The identified proteins were categorized into different functions groups including protein, carbohydrate, energy and lipid metabolisms, cytoskeleton-associated proteins, detoxification, homeostasis, cell communication, constitutive and allergen. This study provides new insights of the protein content in the Dufour's gland contributing to a more complete understanding of the biological functions of this gland in honeybees.

Proteomic analysis in the Dufour's gland of Africanized Apis mellifera workers (Hymenoptera: Apidae).

Science.gov (United States)

Teixeira, Aparecida das Dores; Games, Patricia D; Katz, Benjamin B; Tomich, John M; Zanuncio, José C; Serrão, José Eduardo

2017-01-01

The colony of eusocial bee Apis mellifera has a reproductive queen and sterile workers performing tasks such as brood care and foraging. Chemical communication plays a crucial role in the maintenance of sociability in bees with many compounds released by the exocrine glands. The Dufour's gland is a non-paired gland associated with the sting apparatus with important functions in the communication between members of the colony, releasing volatile chemicals that influence workers roles and tasks. However, the protein content in this gland is not well studied. This study identified differentially expressed proteins in the Dufour's glands of nurse and forager workers of A. mellifera through 2D-gel electrophoresis and mass spectrometry. A total of 131 spots showed different expression between nurse and forager bees, and 28 proteins were identified. The identified proteins were categorized into different functions groups including protein, carbohydrate, energy and lipid metabolisms, cytoskeleton-associated proteins, detoxification, homeostasis, cell communication, constitutive and allergen. This study provides new insights of the protein content in the Dufour's gland contributing to a more complete understanding of the biological functions of this gland in honeybees.

Honeybee Colony Vibrational Measurements to Highlight the Brood Cycle.

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Martin Bencsik

Full Text Available Insect pollination is of great importance to crop production worldwide and honey bees are amongst its chief facilitators. Because of the decline of managed colonies, the use of sensor technology is growing in popularity and it is of interest to develop new methods which can more accurately and less invasively assess honey bee colony status. Our approach is to use accelerometers to measure vibrations in order to provide information on colony activity and development. The accelerometers provide amplitude and frequency information which is recorded every three minutes and analysed for night time only. Vibrational data were validated by comparison to visual inspection data, particularly the brood development. We show a strong correlation between vibrational amplitude data and the brood cycle in the vicinity of the sensor. We have further explored the minimum data that is required, when frequency information is also included, to accurately predict the current point in the brood cycle. Such a technique should enable beekeepers to reduce the frequency with which visual inspections are required, reducing the stress this places on the colony and saving the beekeeper time.

Influence of maternal depression on children's brooding rumination: Moderation by CRHR1 TAT haplotype.

Science.gov (United States)

Woody, Mary L; Kudinova, Anastacia Y; McGeary, John E; Knopik, Valerie S; Palmer, Rohan H C; Gibb, Brandon E

2016-01-01

There is growing evidence that brooding rumination plays a key role in the intergenerational transmission of major depressive disorder (MDD) and may be an endophenotype for depression risk. However, less is known about the mechanisms underlying this role. Therefore, the goal of the current study was to examine levels of brooding in children of mothers with a history of MDD (n = 129) compared to children of never depressed mothers (n = 126) and to determine whether the variation in a gene known to influence hypothalamic-pituitary-adrenal axis functioning--corticotropin-releasing hormone receptor 1 (CRHR1)--would moderate the link between maternal MDD and children's levels of brooding. We predicted children of mothers with a history of MDD would exhibit higher levels of brooding than children of mothers with no lifetime depression history but that this link would be stronger among children carrying no copies of the protective CRHR1 TAT haplotype. Our results supported these hypotheses and suggest that the development of brooding among children of depressed mothers, particularly children without the protective CRHR1 haplotype, may serve as an important mechanism of risk for the intergenerational transmission of depression.

Southwestern willow flycatchers (Empidonax traillii extimus) in a grazed landscape: factors influencing brood parasitism

Science.gov (United States)

Katherine M. Brodhead; Scott H. Stoleson; Deborah M. Finch

2007-01-01

Brood parasitism by Brown-headed Cowbirds (Molothrus ater; hereafter "cowbirds") is an important factor contributing to the endangered status of the Southwestern Willow Flycatcher (Empidonax traillii extimus, hereafter "flycatcher"). We report on factors that influence brood parasitism on the flycatcher using...

Effects of the neonicotinoid pesticide thiamethoxam at field-realistic levels on microcolonies of Bombus terrestris worker bumble bees.

Science.gov (United States)

Laycock, Ian; Cotterell, Katie C; O'Shea-Wheller, Thomas A; Cresswell, James E

2014-02-01

Neonicotinoid pesticides are currently implicated in the decline of wild bee populations. Bumble bees, Bombus spp., are important wild pollinators that are detrimentally affected by ingestion of neonicotinoid residues. To date, imidacloprid has been the major focus of study into the effects of neonicotinoids on bumble bee health, but wild populations are increasingly exposed to alternative neonicotinoids such as thiamethoxam. To investigate whether environmentally realistic levels of thiamethoxam affect bumble bee performance over a realistic exposure period, we exposed queenless microcolonies of Bombus terrestris L. workers to a wide range of dosages up to 98 μgkg(-1) in dietary syrup for 17 days. Results showed that bumble bee workers survived fewer days when presented with syrup dosed at 98 μg thiamethoxamkg(-1), while production of brood (eggs and larvae) and consumption of syrup and pollen in microcolonies were significantly reduced by thiamethoxam only at the two highest concentrations (39, 98 μgkg(-1)). In contrast, we found no detectable effect of thiamethoxam at levels typically found in the nectars of treated crops (between 1 and 11 μgkg(-1)). By comparison with published data, we demonstrate that during an exposure to field-realistic concentrations lasting approximately two weeks, brood production in worker bumble bees is more sensitive to imidacloprid than thiamethoxam. We speculate that differential sensitivity arises because imidacloprid produces a stronger repression of feeding in bumble bees than thiamethoxam, which imposes a greater nutrient limitation on production of brood. © 2013 Published by Elsevier Inc.

Should I stay or should I go? Female brood desertion and male counterstrategy in rock sparrows

DEFF Research Database (Denmark)

Griggio, Matteo; Matessi, Giuliano; Pilastro, Andrea

2005-01-01

petronia), a species in which females can desert their first brood before the nestlings from the first brood leave the nest. We predicted that the male would either desert the brood first or stay even if this implied the risk of caring for the brood alone. We found that males mated to loaded females did...... not leave but stayed and significantly increased their courtship rate and mate guarding. Unexpectedly, they also increased their food provisioning to the nestlings, even though loaded females did not reduce their nestling-feeding rate. The increase in male feeding rate may be explained as a way for the male...... to reduce the female's propensity to switch mate and desert or to increase her propensity to copulate with the male to obtain paternity in her next brood. Altogether, our results demonstrate that the perception of the risk of being deserted by the female does not necessarily induce males to desert first...

Escalation of a coevolutionary arms race through host rejection of brood parasitic young.

Science.gov (United States)

Langmore, Naomi E; Hunt, Sarah; Kilner, Rebecca M

2003-03-13

Cuckoo nestlings that evict all other young from the nest soon after hatching impose a high reproductive cost on their hosts. In defence, hosts have coevolved strategies to prevent brood parasitism. Puzzlingly, they do not extend beyond the egg stage. Thus, hosts adept at recognizing foreign eggs remain vulnerable to exploitation by cuckoo nestlings. Here we show that the breach of host egg defences by cuckoos creates a new stage in the coevolutionary cycle. We found that defences used during the egg-laying period by host superb fairy-wrens (Malurus cyaneus) are easily evaded by the Horsfield's bronze-cuckoo (Chrysococcyx basalis), a specialist fairy-wren brood parasite. However, although hosts never deserted their own broods, they later abandoned 40% of nests containing a lone Horsfield's bronze-cuckoo nestling, and 100% of nests with a lone shining bronze-cuckoo nestling (Chrysococcyx lucidus), an occasional fairy-wren brood parasite. Our experiments demonstrate that host discrimination against evictor-cuckoo nestlings is possible, and suggest that it has selected for the evolution of nestling mimicry in bronze-cuckoos.

The internal-brooding apparatus in the bryozoan genus Cauloramphus (Cheilostomata: Calloporidae) and its inferred homology to ovicells.

Science.gov (United States)

Ostrovsky, Andrew N; Dick, Matthew H; Mawatari, Shunsuke F

2007-12-01

We studied by SEM the external morphology of the ooecium in eight bryozoans of the genus Cauloramphus (Cheilostomata, Calloporidae): C. spinifer, C. variegatus, C. magnus, C. multiavicularia, C. tortilis, C. cryptoarmatus, C. niger, and C. multispinosus, and by sectioning and light microscopy the anatomy of the brooding apparatus of C. spinifer, C. cryptoarmatus, and C. niger. These species all have a brood sac, formed by invagination of the non-calcified distal body wall of the maternal zooid, located in the distal half of the maternal (egg-producing) autozooid, and a vestigial, maternally budded kenozooidal ooecium. The brood sac comprises a main chamber and a long passage (neck) opening externally independently of the introvert. The non-calcified portion of the maternal distal wall between the neck and tip of the zooidal operculum is involved in closing and opening the brood sac, and contains both musculature and a reduced sclerite that suggest homology with the ooecial vesicle of a hyperstomial ovicell. We interpret the brooding apparatus in Cauloramphus as a highly modified form of cheilostome hyperstomial ovicell, as both types share 1) a brood chamber bounded by 2) the ooecium and 3) a component of the distal wall of the maternal zooid. We discuss Cauloramphus as a hypothetical penultimate stage in ovicell reduction in calloporid bryozoans. We suggest that the internal-brooding genus Gontarella, of uncertain taxonomic affinities, is actually a calloporid and represents the ultimate stage in which no trace of the ooecium remains. Internal brooding apparently evolved several times independently within the Calloporidae.

Hygienic behaviour in Brazilian stingless bees

Science.gov (United States)

Alves, Denise A.; Bento, José M. S.; Marchini, Luis C.; Ratnieks, Francis L. W.

2016-01-01

ABSTRACT Social insects have many defence mechanisms against pests and pathogens. One of these is hygienic behaviour, which has been studied in detail in the honey bee, Apis mellifera. Hygienic honey bee workers remove dead and diseased larvae and pupae from sealed brood cells, thereby reducing disease transfer within the colony. Stingless bees, Meliponini, also rear broods in sealed cells. We investigated hygienic behaviour in three species of Brazilian stingless bees (Melipona scutellaris, Scaptotrigona depilis, Tetragonisca angustula) in response to freeze-killed brood. All three species had high mean levels of freeze-killed brood removal after 48 h ∼99% in M. scutellaris, 80% in S. depilis and 62% in T. angustula (N=8 colonies per species; three trials per colony). These levels are greater than in unselected honey bee populations, ∼46%. In S. depilis there was also considerable intercolony variation, ranging from 27% to 100% removal after 2 days. Interestingly, in the S. depilis colony with the slowest removal of freeze-killed brood, 15% of the adult bees emerging from their cells had shrivelled wings indicating a disease or disorder, which is as yet unidentified. Although the gross symptoms resembled the effects of deformed wing virus in the honey bee, this virus was not detected in the samples. When brood comb from the diseased colony was introduced to the other S. depilis colonies, there was a significant negative correlation between freeze-killed brood removal and the emergence of deformed worker bees (P=0.001), and a positive correlation with the cleaning out of brood cells (P=0.0008). This shows that the more hygienic colonies were detecting and removing unhealthy brood prior to adult emergence. Our results indicate that hygienic behaviour may play an important role in colony health in stingless bees. The low levels of disease normally seen in stingless bees may be because they have effective mechanisms of disease management, not because they lack

Hygienic behaviour in Brazilian stingless bees

Directory of Open Access Journals (Sweden)

Hasan Al Toufailia

2016-11-01

Full Text Available Social insects have many defence mechanisms against pests and pathogens. One of these is hygienic behaviour, which has been studied in detail in the honey bee, Apis mellifera. Hygienic honey bee workers remove dead and diseased larvae and pupae from sealed brood cells, thereby reducing disease transfer within the colony. Stingless bees, Meliponini, also rear broods in sealed cells. We investigated hygienic behaviour in three species of Brazilian stingless bees (Melipona scutellaris, Scaptotrigona depilis, Tetragonisca angustula in response to freeze-killed brood. All three species had high mean levels of freeze-killed brood removal after 48 h ∼99% in M. scutellaris, 80% in S. depilis and 62% in T. angustula (N=8 colonies per species; three trials per colony. These levels are greater than in unselected honey bee populations, ∼46%. In S. depilis there was also considerable intercolony variation, ranging from 27% to 100% removal after 2 days. Interestingly, in the S. depilis colony with the slowest removal of freeze-killed brood, 15% of the adult bees emerging from their cells had shrivelled wings indicating a disease or disorder, which is as yet unidentified. Although the gross symptoms resembled the effects of deformed wing virus in the honey bee, this virus was not detected in the samples. When brood comb from the diseased colony was introduced to the other S. depilis colonies, there was a significant negative correlation between freeze-killed brood removal and the emergence of deformed worker bees (P=0.001, and a positive correlation with the cleaning out of brood cells (P=0.0008. This shows that the more hygienic colonies were detecting and removing unhealthy brood prior to adult emergence. Our results indicate that hygienic behaviour may play an important role in colony health in stingless bees. The low levels of disease normally seen in stingless bees may be because they have effective mechanisms of disease management, not because

Experimental dissociation of individual quality, food and timing of breeding effects on double-brooding in a migratory songbird.

Science.gov (United States)

O'Brien, Erin L; Dawson, Russell D

2013-07-01

Annual reproductive success in many species is influenced by the number of breeding attempts within a season. Although previous studies have shown isolated effects of female quality, food, and timing of breeding on the probability of female birds producing second broods, to our knowledge, none have tested the relative importance of multiple factors and their interactions using simultaneous manipulations within populations of free-living birds. In this study, we show that individual quality and timing of breeding interact to affect the probability of double-brooding in female mountain bluebirds (Sialia currucoides). High-quality females (those that naturally initiated clutches early in the season) were more likely to double-brood, regardless of whether their hatching date was advanced or delayed, whereas later breeding, lower quality females were much less likely to double-brood when their first attempt was delayed. This indicates that annual fecundity of poorer quality (or younger) female bluebirds may be more sensitive to seasonal variation in environmental conditions. In addition, birds that were provided with supplemental food throughout first breeding attempts were more likely to double-brood in one of the study years, suggesting that female bluebirds may be energetically limited in their capacity to initiate a second brood. Females that had their first brood delayed also had a shorter inter-brood interval and were moulting fewer feathers during second broods compared to controls, while females in better condition showed more advanced moult in second breeding attempts. Taken together, our results demonstrate the combined effects of age- or individual quality-mediated energetic trade-offs between current and future reproduction, and between investments in offspring and self-maintenance, on annual fecundity of female birds.

Vasodilatory effects of exogenous nitric oxide on the brood patch of the Zebra finch (Taeniopygia guttata)

OpenAIRE

Södergren, Anna

2010-01-01

In birds like the Zebra finch (Taeniopygia guttata) the female, but not the male develop a brood patch upon incubation of eggs. The brood patch functions to increase heat exchange between the bird and the eggs. Development of the brood patch includes de-feathering, increased vascularization and edema formation. The increased vascularization is due to the development of arteriovenous anastomoses, AVA. The AVA are thermoregulatory vessels involved in cold induced vasodilation, CIVD, demonstrate...

Ecological and physiological factors affecting brood patch area and prolactin levels in arctic-nesting geese

Science.gov (United States)

Jonsson, J.E.; Afton, A.D.; Alisauskas, R.T.; Bluhm, C.K.; El Halawani, M.E.

2006-01-01

We investigated effects of ecological and physiological factors on brood patch area and prolactin levels in free-ranging Lesser Snow Geese (Chen caerulescens caerulescens; hereafter “Snow Geese”) and Ross's Geese (C. rossii). On the basis of the body-size hypothesis, we predicted that the relationships between prolactin levels, brood patch area, and body condition would be stronger in Ross's Geese than in the larger Snow Geese. We found that brood patch area was positively related to clutch volume and inversely related to prolactin levels in Ross's Geese, but not in Snow Geese. Nest size, nest habitat, and first egg date did not affect brood patch area in either species. Prolactin levels increased as incubation progressed in female Snow Geese, but this relationship was not significant in Ross's Geese. Prolactin levels and body condition (as indexed by size-adjusted body mass) were inversely related in Ross's Geese, but not in Snow Geese. Our findings are consistent with the prediction that relationships between prolactin levels, brood patch area, and body condition are relatively stronger in Ross's Geese, because they mobilize endogenous reserves at faster rates than Snow Geese.

Division of labor associated with brood rearing in the honey bee: how does it translate to colony fitness?

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Ramesh R Sagili

2011-02-01

Full Text Available Division of labor is a striking feature observed in honey bees and many other social insects. Division of labor has been claimed to benefit fitness. In honey bees, the adult work force may be viewed as divided between non-foraging hive bees that rear brood and maintain the nest, and foragers that collect food outside the nest. Honey bee brood pheromone is a larval pheromone that serves as an excellent empirical tool to manipulate foraging behaviors and thus division of labor in the honey bee. Here we use two different doses of brood pheromone to alter the foraging stimulus environment, thus changing demographics of colony division of labor, to demonstrate how division of labor associated with brood rearing affects colony growth rate. We examine the effects of these different doses of brood pheromone on individual foraging ontogeny and specialization, colony level foraging behavior, and individual glandular protein synthesis. Low brood pheromone treatment colonies exhibited significantly higher foraging population, decreased age of first foraging and greater foraging effort, resulting in greater colony growth compared to other treatments. This study demonstrates how division of labor associated with brood rearing affects honey bee colony growth rate, a token of fitness.

Seahorse Brood Pouch Transcriptome Reveals Common Genes Associated with Vertebrate Pregnancy.

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Whittington, Camilla M; Griffith, Oliver W; Qi, Weihong; Thompson, Michael B; Wilson, Anthony B

2015-12-01

Viviparity (live birth) has evolved more than 150 times in vertebrates, and represents an excellent model system for studying the evolution of complex traits. There are at least 23 independent origins of viviparity in fishes, with syngnathid fishes (seahorses and pipefish) unique in exhibiting male pregnancy. Male seahorses and pipefish have evolved specialized brooding pouches that provide protection, gas exchange, osmoregulation, and limited nutrient provisioning to developing embryos. Pouch structures differ widely across the Syngnathidae, offering an ideal opportunity to study the evolution of reproductive complexity. However, the physiological and genetic changes facilitating male pregnancy are largely unknown. We used transcriptome profiling to examine pouch gene expression at successive gestational stages in a syngnathid with the most complex brood pouch morphology, the seahorse Hippocampus abdominalis. Using a unique time-calibrated RNA-seq data set including brood pouch at key stages of embryonic development, we identified transcriptional changes associated with brood pouch remodeling, nutrient and waste transport, gas exchange, osmoregulation, and immunological protection of developing embryos at conception, development and parturition. Key seahorse transcripts share homology with genes of reproductive function in pregnant mammals, reptiles, and other live-bearing fish, suggesting a common toolkit of genes regulating pregnancy in divergent evolutionary lineages. © The Author 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Microhabitat selection of brood-rearing sites by greater sage-grouse in Carbon County, Wyoming

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Leslie A. Schreiber; Christopher P. Hansen; Mark A. Rumble; Joshua J. Millspaugh; R. Scott Gamo; Jon W. Kehmeier; Nate Wojcik

2015-01-01

Declines in Greater Sage-Grouse (Centrocercus urophasianus, hereafter sage-grouse) populations could be attributed to low chick survival, which may be influenced by the availability of food and cover at sites used by females rearing broods. Habitat attributes important to broods may vary regionally; thus, it is necessary to understand factors affecting...

Flexible parents: joint effects of handicapping and brood size manipulation on female parental care in Nicrophorus vespilloides.

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Ratz, Tom; Smiseth, Per T

2018-02-22

Parental care is highly variable, reflecting that parents make flexible decisions in response to variation in the cost of care to themselves and the benefit to their offspring. Much of the evidence that parents respond to such variation derives from handicapping and brood size manipulations, the separate effects of which are well understood. However, little is known about their joint effects. Here, we fill this gap by conducting a joint handicapping and brood size manipulation in the burying beetle Nicrophorus vespilloides. We handicapped half of the females by attaching a lead weight to their pronotum, leaving the remaining females as controls. We also manipulated brood size by providing each female with 5, 20 or 40 larvae. In contrast to what we predicted, handicapped females spent more time provisioning food than controls. We also found that handicapped females spent more time consuming carrion. Furthermore, handicapped females spent a similar amount of time consuming carrion regardless of brood size, whereas controls spent more time consuming carrion as brood increased. Females spent more time provisioning food towards larger broods, and females were more likely to engage in carrion consumption when caring for larger broods. We conclude that females respond to both handicapping and brood size manipulations, but these responses are largely independent of each other. Overall, our results suggest that handicapping might lead to a higher investment into current reproduction and that it might be associated with compensatory responses that negate the detrimental impact of higher cost of care in handicapped parents. © 2018 Crown copyright. Journal of Evolutionary Biology © 2018 European Society For Evolutionary Biology This article is published with the permission of the Controller of HMSO and the Queen’s Printer for Scotland. Note: some government agencies may require additional wording and acknowledgement.

Survival of female white-cheeked pintails during brood rearing in Puerto Rico

Science.gov (United States)

Lopez-Flores, Marisel; Davis, J. Brian; Vilella, Francisco; Kaminski, Richard M.; Cruz-Burgos, José A.; Lancaster, Joseph D.

2014-01-01

Anas bahamensis (White-cheeked Pintail) is widely distributed across the Caribbean islands and South America. The species is classified as threatened in Puerto Rico and a species of least concern across most of its range. Little demographic data exist for the species, particularly during the breeding season. During 2000-2002, we radiomarked 31 incubating females at the Humacao Nature Reserve (Humacao) in southeastern Puerto Rico and estimated daily and interval survival rates of females during brood rearing. Only one of 31 birds died; the average ±95% CI daily survival rate of pintails was 0.998 ± 0.989-0.999 for all years, and interval survival was 0.913 ± 0.527-0.987 for a 60-day brood-rearing period. High survival of females suggests their mortality during brood rearing does not influence White-cheeked Pintail populations at Humacao, but further studies of reproductive and annual ecology are needed.

Interaction between the solitary bee Chelostoma florisomne and its nest parasite Sapyga clavicornis - empty cells reduce the impact of parasites

DEFF Research Database (Denmark)

Münster-Swendsen (deceased), Mikael; Calabuig, Isabel

2000-01-01

Summary 1. Nesting behaviour and interactions between the bee Chelostoma florisomne (L.) (Megachilidae) and its nest parasite Sapyga clavicornis (L.) (Sapygidae) were studied through continual observations of individuals and dissections of bee nests. Protection of bee offspring is based on (1.......4% of all brood cells and, if the outermost brood cell in a nest was excluded, in front of 74.3% of inner brood cells. A vestibule closure is most often constructed in front of the outermost brood cell. 3. Following oviposition, the bee made only five flights, which together lasted 6–13 min, to construct...... a cell closure. A cell closure does not prevent the nest parasite from oviposition inside the brood cell, however, and parasite eggs deposited through the cell closure are not detected and removed by the bee. Only an additional cell closure, i.e. the formation of an empty cell, may protect a brood cell...

Metal contaminant accumulation in the hive: Consequences for whole-colony health and brood production in the honey bee (Apis mellifera L.).

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Hladun, Kristen R; Di, Ning; Liu, Tong-Xian; Trumble, John T

2016-02-01

Metal pollution has been increasing rapidly over the past century, and at the same time, the human population has continued to rise and produce contaminants that may negatively impact pollinators. Honey bees (Apis mellifera L.) forage over large areas and can collect contaminants from the environment. The primary objective of the present study was to determine whether the metal contaminants cadmium (Cd), copper (Cu), lead (Pb), and selenium (Se) can have a detrimental effect on whole-colony health in the managed pollinator A. mellifera. The authors isolated small nucleus colonies under large cages and fed them an exclusive diet of sugar syrup and pollen patty spiked with Cd, Cu, Pb, and Se or a control (no additional metal). Treatment levels were based on concentrations in honey and pollen from contaminated hives around the world. They measured whole-colony health including wax, honey, and brood production; colony weight; brood survival; and metal accumulation in various life stages. Colonies treated with Cd or Cu contained more dead pupae within capped cells compared with control, and Se-treated colonies had lower total worker weights compared to control. Lead had a minimal effect on colony performance, although many members of the hive accumulated significant quantities of the metal. By examining the honey bee as a social organism through whole-colony assessments of toxicity, the authors found that the distribution of toxicants throughout the colony varied from metal to metal, some caste members were more susceptible to certain metals, and the colony's ability to grow over time may have been reduced in the presence of Se. Apiaries residing near metal-contaminated areas may be at risk and can suffer changes in colony dynamics and survival. © 2015 SETAC.

Comparative anatomical study of internal brooding in three anascan bryozoans (Cheilostomata) and its taxonomic and evolutionary implications.

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Ostrovsky, Andrew N; Grischenko, Andrei V; Taylor, Paul D; Bock, Phil; Mawatari, Shunsuke F

2006-06-01

The anatomical structure of internal sacs for embryonic incubation was studied using SEM and light microscopy in three cheilostome bryozoans-Nematoflustra flagellata (Waters,1904), Gontarella sp., and Biflustra perfragilis MacGillivray, 1881. In all these species the brood sac is located in the distal half of the maternal (egg-producing) autozooid, being a conspicuous invagination of the body wall. It consists of the main chamber and a passage (neck) to the outside that opens independently of the introvert. There are several groups of muscles attached to the thin walls of the brood sac and possibly expanding it during oviposition and larval release. Polypide recycling begins after oviposition in Gontarella sp., and the new polypide bud is formed by the beginning of incubation. Similarly, polypides in brooding zooids degenerate in N. flagellata and, sometimes, in B. perfragilis. In the evolution of brood chambers in the Cheilostomata, such internal sacs for embryonic incubation are considered a final step, being the result of immersion of the brooding cavity into the maternal zooid and reduction of the protecting fold (ooecium). Possible reasons for this transformation are discussed, and the hypothesis of Santagata and Banta (Santagata and Banta1996) that internal brooding evolved prior to incubation in ovicells is rejected. J. Morphol. (c) 2006 Wiley-Liss, Inc.

Worker life tables, survivorship, and longevity in colonies of Bombus (Fervidobombus atratus (Hymenoptera: Apidae

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Eunice Vieira da Silva-Matos

2000-06-01

Full Text Available Survivorship curves and longevity of workers were studied in two queenright and two queenless colonies of Bombus (Fervidobombus atratus. Survivorship curves for workers of all colonies were, in general, convex, indicating an increasing mortality rate with increasing age. The mean longevity for the workers from queenright colonies, 24.3 days and 17.6 days, was not significantly different from that in queenless colonies, 21.2 days and 20.2 days. In all colonies workers started foraging activities when aged 0-5 days, and the potential forager rates rose progressively with increasing age. Mortality rates within each age interval were significantly correlated with the foraging worker rates in all colonies. Only in two of the colonies (one queenright and one queenless longevity was significantly correlated with worker size. The duration of brood development period seems to be one of the most important factors influencing adult worker longevity in this bumble bee species.

The Evolution of Clutch Size in Hosts of Avian Brood Parasites.

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Medina, Iliana; Langmore, Naomi E; Lanfear, Robert; Kokko, Hanna

2017-11-01

Coevolution with avian brood parasites shapes a range of traits in their hosts, including morphology, behavior, and breeding systems. Here we explore whether brood parasitism is also associated with the evolution of host clutch size. Several studies have proposed that hosts of highly virulent parasites could decrease the costs of parasitism by evolving a smaller clutch size, because hosts with smaller clutches will lose fewer progeny when their clutch is parasitized. We describe a model of the evolution of clutch size, which challenges this logic and shows instead that an increase in clutch size (or no change) should evolve in hosts. We test this prediction using a broad-scale comparative analysis to ask whether there are differences in clutch size within hosts and between hosts and nonhosts. Consistent with our model, this analysis revealed that host species do not have smaller clutches and that hosts that incur larger costs from raising a parasite lay larger clutches. We suggest that brood parasitism might be an influential factor in clutch-size evolution and could potentially select for the evolution of larger clutches in host species.

Control del parásito Varroa destructor (Acari: Varroidae en colmenas de la abeja Apis mellifera (Hymenoptera: Apidae mediante la aplicación de la técnica de entrampado Control of the parasite Varroa destructor (Acari: Varroidae in honeybee colonies of Apis mellifera (Hymenoptera: Apidae applying brood trap combs

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Natalia Damiani

2006-07-01

technique as possible control method of mite Varroa destructor (Anderson & Trueman. Work was done at Coronel Vidal, province of Buenos Aires using Langstroth hives of the local hybrid of Apis mellifera (Linneaus. In each colony, the queen was confined in one brood comb to control queen oviposition. After capped, these combs were taken to the laboratory to uncapp each cell and to examinate the total number of trapped parasites. This technique was applied varying the number of brood tramp combs (1-3 for worker and drone brood cells. Also, the impact of this technique on normal development of the colonies were evaluated by means of its honey production. Results showed that this technique is only effective when three drone brood tramp combs were applied, reaching a total efficacy of 84%. When worker brood combs were used, total efficacy was significant lower (14%. Honey production was significant lower in test colonies compared to control ones. Brood tramp combs technique represent a good alternative method to be combined with other control methods, decreasing the presence of chemical sustances and residues in honey and the possible resistant mite populations.

Beneficial Insect Borders Provide Northern Bobwhite Brood Habitat

Science.gov (United States)

Moorman, Christopher E.; Plush, Charles J.; Orr, David B.; Reberg-Horton, Chris

2013-01-01

Strips of fallow vegetation along cropland borders are an effective strategy for providing brood habitat for declining populations of upland game birds (Order: Galliformes), including northern bobwhite (Colinus virginianus), but fallow borders lack nectar-producing vegetation needed to sustain many beneficial insect populations (e.g., crop pest predators, parasitoids, and pollinator species). Planted borders that contain mixes of prairie flowers and grasses are designed to harbor more diverse arthropod communities, but the relative value of these borders as brood habitat is unknown. We used groups of six human-imprinted northern bobwhite chicks as a bioassay for comparing four different border treatments (planted native grass and prairie flowers, planted prairie flowers only, fallow vegetation, or mowed vegetation) as northern bobwhite brood habitat from June-August 2009 and 2010. All field border treatments were established around nine organic crop fields. Groups of chicks were led through borders for 30-min foraging trials and immediately euthanized, and eaten arthropods in crops and gizzards were measured to calculate a foraging rate for each border treatment. We estimated arthropod prey availability within each border treatment using a modified blower-vac to sample arthropods at the vegetation strata where chicks foraged. Foraging rate did not differ among border treatments in 2009 or 2010. Total arthropod prey densities calculated from blower-vac samples did not differ among border treatments in 2009 or 2010. Our results showed plant communities established to attract beneficial insects should maximize the biodiversity potential of field border establishment by providing habitat for beneficial insects and young upland game birds. PMID:24376759

Out with the garbage: the parasitic strategy of the mantisfly Plega hagenella mass-infesting colonies of the eusocial bee Melipona subnitida in northeastern Brazil

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Maia-Silva, Camila; Hrncir, Michael; Koedam, Dirk; Machado, Renato Jose Pires; Imperatriz-Fonseca, Vera Lucia

2013-01-01

Between April and June of 2012 mantisflies ( Plega hagenella) were found to be extensively parasitizing the nests of two groups of managed colonzies of eusocial stingless bees ( Melipona subnitida) in the semi-arid region of northeastern Brazil. The mantisfly larvae developed inside closed brood cells of the bee comb, where each mantispid larva fed on the bee larva or pupa present in a single brood cell. Mature mantispid larvae pupated inside silken cocoons spun in place within their hosts' brood cells then emerged as pharate adults inside the bee colony. Pharate adults were never attacked and killed by host colony workers. Instead, colony workers picked up the pharates and removed them from the nest unharmed, treating them similar to the way that the general refuse is removed from the nest. Adult mantispids subsequently eclosed from their pupal exuviae outside the nest. Manipulative experiments showed that post-eclosion adult mantispids placed back within active bee colonies were quickly attacked and killed. These observations demonstrate that pharate and post-eclosion adults of P. hagenella are perceived differently by colony workers and that delayed adult eclosion is an important functional element in the parasitic life strategy of P. hagenella, allowing adults to escape without injury from the bee colonies they parasitize.

Influence of habitat and number of nestlings on partial brood loss in red-cockaded woodpeckers

Science.gov (United States)

James R. McCormick; Richard N. Conner; D. Brent Burt; Daniel Saenz

2004-01-01

Partial brood loss in red-cockaded woodpeckers (Picoides borealis) was studied during 2 breeding seasons in eastern Texas. The timing of partial brood loss, group size, number of initial nestlings, number of birds fledged, and habitat characteristics of the group's cavity-tree cluster were examined for 37 woodpecker groups in loblolly- (

Spatial patterns, ecological niches, and interspecific competition of avian brood parasites: inferring from a case study of Korea.

Science.gov (United States)

Lee, Jin-Won; Noh, Hee-Jin; Lee, Yunkyoung; Kwon, Young-Soo; Kim, Chang-Hoe; Yoo, Jeong-Chil

2014-09-01

Since obligate avian brood parasites depend completely on the effort of other host species for rearing their progeny, the availability of hosts will be a critical resource for their life history. Circumstantial evidence suggests that intense competition for host species may exist not only within but also between species. So far, however, few studies have demonstrated whether the interspecific competition really occurs in the system of avian brood parasitism and how the nature of brood parasitism is related to their niche evolution. Using the occurrence data of five avian brood parasites from two sources of nationwide bird surveys in South Korea and publically available environmental/climatic data, we identified their distribution patterns and ecological niches, and applied species distribution modeling to infer the effect of interspecific competition on their spatial distribution. We found that the distribution patterns of five avian brood parasites could be characterized by altitude and climatic conditions, but overall their spatial ranges and ecological niches extensively overlapped with each other. We also found that the predicted distribution areas of each species were generally comparable to the realized distribution areas, and the numbers of individuals in areas where multiple species were predicted to coexist showed positive relationships among species. In conclusion, despite following different coevolutionary trajectories to adapt to their respect host species, five species of avian brood parasites breeding in South Korea occupied broadly similar ecological niches, implying that they tend to conserve ancestral preferences for ecological conditions. Furthermore, our results indicated that contrary to expectation interspecific competition for host availability between avian brood parasites seemed to be trivial, and thus, play little role in shaping their spatial distributions and ecological niches. Future studies, including the complete ranges of avian brood

Chromosome aberrations and rogue cells in lymphocytes of Chernobyl clean-up workers

International Nuclear Information System (INIS)

Lazutka, J.R.

1996-01-01

A cytogenetic analysis was performed on peripheral blood lymphocytes from 183 Chernobyl clean-up workers and 27 control individuals. Increased frequencies of chromosome aberrations were associated with exposure to radiation at Chernobyl, alcohol abuse and a history of recent influenza infection. However, only approximately 20% of Chernobyl clean-up workers had an increased frequency of dicentric and ring chromosomes. At the same time, an increased frequency of acentric fragments in lymphocytes of clean-up workers was characteristic. The use of multivitamins as dietary supplement significantly decreased the frequency of chromosome aberrations, especially of chromatid breaks. Rogue cells were found in lymphocytes of 28 clean-up workers and 3 control individuals. The appearance of rogue cells was associated with a recent history of acute respiratory disease (presumably caused by adenoviral infection) and, probably, alcohol abuse. Dicentric chromosomes in rogue cells were distributed according to a negative binomial distribution. Occurrence of rogue cells due to a perturbation of cell cycle control and abnormal apoptosis is suggested

Fish embryo and juvenile size under hypoxia in the mouth-brooding African cichlid Pseudocrenilabrus multicolor

Institute of Scientific and Technical Information of China (English)

E.E.REARDON; L.J.CHAPMAN

2012-01-01

We used a field survey and a laboratory rearing experiment to (a) examine response (size and survival) to life-long hypoxia in offspring of the African maternal mouth-brooding cichlid Pseudocrenilabrus multicolor victoriae (Seegers) and (b) explore the degree to which developmental response can be environmentally-induced.Embryo size metrics were quantified in 9 field populations across a range of dissolved oxygen (DO) concentrations.In the laboratory,first generation (F1) broods of low-DO origin were reared under high or low DO.Brooding period was quantified for the mothers; and egg size,egg metabolic rate and juvenile size-at-release were quantified in their (F2) offspring.The F2 offspring were split and grown for 3 months post-release under high or low DO,and juvenile size and survival were quantified.In the field survey,across stages,embryos from low-DO field populations were shorter and weighed less than embryos from high-DO populations.In the laboratory experiment,F2 eggs and juveniles-at-release from mother's mouth did not differ in mass,length,survival regardless of development DO environment.However,juveniles diverged in size after leaving mother's mouth,exhibiting smaller size when grown under low DO.Size differences in embryo size across field populations and divergence in embryo size after release from the mother's mouthsupport predictions for smaller body size under hypoxia.There was no evidence for negative effects on survival of juveniles after 3 months.Brooding period was 16％ shorter in females reared under low DO suggesting that hypoxia may accelerate embryo development.This work provides insights into how bearer fishes respond to hypoxic stress relative to fishes with no post-spawning parental care; a shorter brooding interval and smaller body size may provide an optimal solution to parent and embryo survival under hypoxia in brooding fishes.

Standardised classification of pre-release development in male-brooding pipefish, seahorses, and seadragons (Family Syngnathidae)

Science.gov (United States)

2012-01-01

Background Members of the family Syngnathidae share a unique reproductive mode termed male pregnancy. Males carry eggs in specialised brooding structures for several weeks and release free-swimming offspring. Here we describe a systematic investigation of pre-release development in syngnathid fishes, reviewing available data for 17 species distributed across the family. This work is complemented by in-depth examinations of the straight-nosed pipefish Nerophis ophidion, the black-striped pipefish Syngnathus abaster, and the potbellied seahorse Hippocampus abdominalis. Results We propose a standardised classification of early syngnathid development that extends from the activation of the egg to the release of newborn. The classification consists of four developmental periods – early embryogenesis, eye development, snout formation, and juvenile – which are further divided into 11 stages. Stages are characterised by morphological traits that are easily visible in live and preserved specimens using incident-light microscopy. Conclusions Our classification is derived from examinations of species representing the full range of brooding-structure complexity found in the Syngnathidae, including tail-brooding as well as trunk-brooding species, which represent independent evolutionary lineages. We chose conspicuous common traits as diagnostic features of stages to allow for rapid and consistent staging of embryos and larvae across the entire family. In view of the growing interest in the biology of the Syngnathidae, we believe that the classification proposed here will prove useful for a wide range of studies on the unique reproductive biology of these male-brooding fish. PMID:23273265

Standardised classification of pre-release development in male-brooding pipefish, seahorses, and seadragons (Family Syngnathidae

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Sommer Stefan

2012-12-01

Full Text Available Abstract Background Members of the family Syngnathidae share a unique reproductive mode termed male pregnancy. Males carry eggs in specialised brooding structures for several weeks and release free-swimming offspring. Here we describe a systematic investigation of pre-release development in syngnathid fishes, reviewing available data for 17 species distributed across the family. This work is complemented by in-depth examinations of the straight-nosed pipefish Nerophis ophidion, the black-striped pipefish Syngnathus abaster, and the potbellied seahorse Hippocampus abdominalis. Results We propose a standardised classification of early syngnathid development that extends from the activation of the egg to the release of newborn. The classification consists of four developmental periods – early embryogenesis, eye development, snout formation, and juvenile – which are further divided into 11 stages. Stages are characterised by morphological traits that are easily visible in live and preserved specimens using incident-light microscopy. Conclusions Our classification is derived from examinations of species representing the full range of brooding-structure complexity found in the Syngnathidae, including tail-brooding as well as trunk-brooding species, which represent independent evolutionary lineages. We chose conspicuous common traits as diagnostic features of stages to allow for rapid and consistent staging of embryos and larvae across the entire family. In view of the growing interest in the biology of the Syngnathidae, we believe that the classification proposed here will prove useful for a wide range of studies on the unique reproductive biology of these male-brooding fish.

Deep-sea octopus (Graneledone boreopacifica) conducts the longest-known egg-brooding period of any animal.

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Robison, Bruce; Seibel, Brad; Drazen, Jeffrey

2014-01-01

Octopuses typically have a single reproductive period and then they die (semelparity). Once a clutch of fertilized eggs has been produced, the female protects and tends them until they hatch. In most shallow-water species this period of parental care can last from 1 to 3 months, but very little is known about the brooding of deep-living species. In the cold, dark waters of the deep ocean, metabolic processes are often slower than their counterparts at shallower depths. Extrapolations from data on shallow-water octopus species suggest that lower temperatures would prolong embryonic development periods. Likewise, laboratory studies have linked lower temperatures to longer brooding periods in cephalopods, but direct evidence has not been available. We found an opportunity to directly measure the brooding period of the deep-sea octopus Graneledone boreopacifica, in its natural habitat. At 53 months, it is by far the longest egg-brooding period ever reported for any animal species. These surprising results emphasize the selective value of prolonged embryonic development in order to produce competitive hatchlings. They also extend the known boundaries of physiological adaptations for life in the deep sea.

Immune cells in Chernobyl radiation workers exposed to low-dose irradiation

International Nuclear Information System (INIS)

Bazyka, D.; Chumak, A.; Byelyaeva, N.; Gulaya, N.; Margytich, V.; Thevenon, C.; Guichardant, M.; Lagarde, M.

2002-01-01

the aim of this work was to study immune response parameters in Chernobyl emergency and recovery operation radiation workers and nuclear industry workers exposed under professional limits. The monohydroxylated fatty acid content in peripheral blood mononuclear cell of radiation workers compared to unexposed control at the 12-th year after Chernobyl NPP accident was studied too

Removal of drone brood from Apis mellifera (Hymenoptera: Apidae) colonies to control Varroa destructor (Acari: Varroidae) and retain adult drones.

Science.gov (United States)

Wantuch, Holly A; Tarpy, David R

2009-12-01

The parasitic mite Varroa destructor Anderson & Trueman (Acari: Varroidae) has plagued European honey bees, Apis mellifera L. (Hymenoptera: Apidae), in the Americas since its introduction in the 1980s. For many years, these mites were sufficiently controlled using synthetic acaricides. Recently, however, beekeepers have experienced increased resistance by mites to chemical pesticides, which are also known to leave residues in hive products such as wax and honey. Thus there has been increased emphasis on nonchemical integrated pest management control tactics for Varroa. Because mites preferentially reproduce in drone brood (pupal males), we developed a treatment strategy focusing on salvaging parasitized drones while removing mites from them. We removed drone brood from colonies in which there was no acaricidal application and banked them in separate "drone-brood receiving" colonies treated with pesticides to kill mites emerging with drones. We tested 20 colonies divided into three groups: 1) negative control (no mite treatment), 2) positive control (treatment with acaricides), and 3) drone-brood removal and placement into drone-brood receiving colonies. We found that drone-brood trapping significantly lowered mite numbers during the early months of the season, eliminating the need for additional control measures in the spring. However, mite levels in the drone-brood removal group increased later in the summer, suggesting that this benefit does not persist throughout the entire season. Our results suggest that this method of drone-brood trapping can be used as an element of an integrated control strategy to control varroa mites, eliminating a large portion of the Varroa population with limited chemical treatments while retaining the benefits of maintaining adult drones in the population.

Fish embryo and juvenile size under hypoxia in the mouth- brooding African cichlid Pseudocrenilabrus multicolor

Directory of Open Access Journals (Sweden)

E.E. REARDON, L.J. CHAPMAN

2012-06-01

Full Text Available We used a field survey and a laboratory rearing experiment to (a examine response (size and survival to life-long hypoxia in offspring of the African maternal mouth-brooding cichlid Pseudocrenilabrus multicolor victoriae (Seegers and (b explore the degree to which developmental response can be environmentally-induced. Embryo size metrics were quantified in 9 field populations across a range of dissolved oxygen (DO concentrations. In the laboratory, first generation (F1 broods of low-DO origin were reared under high or low DO. Brooding period was quantified for the mothers; and egg size, egg metabolic rate and juvenile size-at-release were quantified in their (F2 offspring. The F2 offspring were split and grown for 3 months post-release under high or low DO, and juvenile size and survival were quantified. In the field survey, across stages, embryos from low-DO field populations were shorter and weighed less than embryos from high-DO populations. In the laboratory experiment, F2 eggs and juveniles-at-release from mother’s mouth did not differ in mass, length, survival regardless of development DO environment. However, juveniles diverged in size after leaving mother’s mouth, exhibiting smaller size when grown under low DO. Size differences in embryo size across field populations and divergence in embryo size after release from the mother’s mouth support predictions for smaller body size under hypoxia. There was no evidence for negative effects on survival of juveniles after 3 months. Brooding period was 16% shorter in females reared under low DO suggesting that hypoxia may accelerate embryo development. This work provides insights into how bearer fishes respond to hypoxic stress relative to fishes with no post-spawning parental care; a shorter brooding interval and smaller body size may provide an optimal solution to parent and embryo survival under hypoxia in brooding fishes [Current Zoology 58 (3: 401-412, 2012].

First record of invasive Burmese Python oviposition and brooding inside an anthropogenic structure

Science.gov (United States)

Hanslowe, Emma; Falk, Bryan; Collier, Michelle A. M.; Josimovich, Jillian; Rahill, Thomas; Reed, Robert

2016-01-01

We discovered an adult female Python bivittatus (Burmese Python) coiled around a clutch of 25 eggs in a cement culvert in Flamingo, FL, in Everglades National Park. To our knowledge, this is the first record of an invasive Burmese Python laying eggs and brooding inside an anthropogenic structure in Florida. A 92% hatch-success rate suggests that the cement culvert provided suitable conditions for oviposition, embryonic development, and hatching. Given the plenitude of such anthropogenic structures across the landscape, available sites for oviposition and brooding may not be limiting for the invasive Burmese Python population.

Assessment of selected B cells populations in the workers of X-ray departments

Directory of Open Access Journals (Sweden)

Piotr Kłuciński

2014-08-01

Full Text Available Objectives: Workers of X-ray departments are occupationally exposed to long-term low levels of ionizing radiation (LLIR, which may affect their humoral immunity. The aim of the study was to assess the influence of LLIR on the number and proportion of B cells (CD19+, B1 cells (CD5+CD19+ and memory B cells (CD27+CD19+ in peripheral blood of such workers. Materials and Methods: In the study group of 47 X-ray departments workers and the control group consisting of 38 persons, the number and percentage of CD19+, CD5+CD19+, CD27+CD19+ cells as well as CD5+CD19+/CD19+ and CD27+CD19+/CD19+ cell ratios were assessed using flow cytometry. Additionally, the study group was divided into 2 groups by the length of employment below and over 15 years and analysis adjusted for age and smoking habit was performed. Results: The total number of CD19+ cells showed significant increase in the group of workers in comparison with the persons from the control group, whereas the percentage of CD5+CD19+ cells as well as CD27+CD19+/CD19+ and CD5+CD19+/CD19+ cell ratios were lower. Percentage, number of CD5+CD19+ cells and CD5+CD19+/CD19+ cell ratio were significantly lower in the workers with length of employment longer than 15 years in comparison with those employed below 15 years. Moreover, we found positive associations between the number of CD19+ cells and employment as well as smoking habit, whereas the number of CD5+CD19+ cells was positively associated with cigarette smoking alone. Percentage of CD5+CD19+ cells as well as CD5+CD19+/CD19+ and CD27+CD19+/CD19+ cell ratios were negatively correlated with employment. Conclusions: The study suggests association between the suppressive influence of low level ionizing radiation on circulating in peripheral blood, especially of B1 cells as well as of memory B cells, in workers of X-ray units, which is adverse in relation to microbiological threat.

Sex-specific effects of altered competition on nestling growth and survival: an experimental manipulation of brood size and sex ratio.

Science.gov (United States)

Nicolaus, Marion; Michler, Stephanie P M; Ubels, Richard; van der Velde, Marco; Komdeur, Jan; Both, Christiaan; Tinbergen, Joost M

2009-03-01

1. An increase of competition among adults or nestlings usually negatively affects breeding output. Yet little is known about the differential effects that competition has on the offspring sexes. This could be important because it may influence parental reproductive decisions. 2. In sexual size dimorphic species, two main contradictory mechanisms are proposed regarding sex-specific effects of competition on nestling performance assuming that parents do not feed their chicks differentially: (i) the larger sex requires more resources to grow and is more sensitive to a deterioration of the rearing conditions ('costly sex hypothesis'); (ii) the larger sex has a competitive advantage in intra-brood competition and performs better under adverse conditions ('competitive advantage hypothesis'). 3. In the present study, we manipulated the level of sex-specific sibling competition in a great tit population (Parus major) by altering simultaneously the brood size and the brood sex ratio on two levels: the nest (competition for food among nestlings) and the woodlot where the parents breed (competition for food among adults). We investigated whether altered competition during the nestling phase affected nestling growth traits and survival in the nest and whether the effects differed between males, the larger sex, and females. 4. We found a strong negative and sex-specific effect of experimental brood size on all the nestling traits. In enlarged broods, sexual size dimorphism was smaller which may have resulted from biased mortality towards the less competitive individuals i.e. females of low condition. No effect of brood sex ratio on nestling growth traits was found. 5. Negative brood size effects on nestling traits were stronger in natural high-density areas but we could not confirm this experimentally. 6. Our results did not support the 'costly sex hypothesis' because males did not suffer from higher mortality under harsh conditions. The 'competitive advantage hypothesis' was

A meta-analysis of lesser prairie-chicken nesting and brood-rearing habitats: implications for habitat management

Science.gov (United States)

Hagen, Christian A.; Grisham, Blake A.; Boal, Clint W.; Haukos, David A.

2013-01-01

The distribution and range of lesser prairie-chicken (Tympanuchus pallidicinctus) has been reduced by >90% since European settlement of the Great Plains of North America. Currently, lesser prairie-chickens occupy 3 general vegetation communities: sand sagebrush (Artemisia filifolia), sand shinnery oak (Quercus havardii), and mixed-grass prairies juxtaposed with Conservation Reserve Program grasslands. As a candidate for protection under the Endangered Species Act, there is a need for a synthesis that characterizes habitat structure rangewide. Thus, we conducted a meta-analysis of vegetation characteristics at nest sites and brood habitats to determine whether there was an overall effect (Hedges' d) of habitat selection and to estimate average (95% CI) habitat characteristics at use sites. We estimated effect sizes (di) from the difference between use (nests and brood sites) and random sampling sites for each study (n = 14), and derived an overall effect size (d++). There was a general effect for habitat selection as evidenced by low levels of variation in effect sizes across studies and regions. There was a small to medium effect (d++) = 0.20-0.82) of selection for greater vertical structure (visual obstruction) by nesting females in both vegetation communities, and selection against bare ground (d++ = 0.20-0.58). Females with broods exhibited less selectivity for habitat components except for vertical structure. The variation of d++ was greater during nesting than brooding periods, signifying a seasonal shift in habitat use, and perhaps a greater range of tolerance for brood-rearing habitat. The overall estimates of vegetation cover were consistent with those provided in management guidelines for the species.

Genetic reincarnation of workers as queens in the Eastern honeybee Apis cerana.

Science.gov (United States)

Holmes, M J; Tan, K; Wang, Z; Oldroyd, B P; Beekman, M

2015-01-01

Thelytokous parthenogenesis, or the asexual production of female offspring, is rare in the animal kingdom, but relatively common in social Hymenoptera. However, in honeybees, it is only known to be ubiquitous in one subspecies of Apis mellifera, the Cape honeybee, A. mellifera capensis. Here we report the appearance of queen cells in two colonies of the Eastern honeybee Apis cerana that no longer contained a queen or queen-produced brood to rear queens from. A combination of microsatellite genotyping and the timing of the appearance of these individuals excluded the possibility that they had been laid by the original queen. Based on the genotypes of these individuals, thelytokous production by natal workers is the most parsimonious explanation for their existence. Thus, we present the first example of thelytoky in a honeybee outside A. mellifera. We discuss the evolutionary and ecological consequences of thelytoky in A. cerana, in particular the role thelytoky may play in the recent invasions by populations of this species.

An evaluation of the possible adaptive function of fungal brood covering by attine ants

DEFF Research Database (Denmark)

Armitage, Sophie Alice Octavia; Fernández-Marín, Hermógenes; Wcislo, William T.

2012-01-01

species, but to varying degrees, and appears to have evolved shortly after the origin of fungus farming, but was partly or entirely abandoned in some genera. To understand the evolution of the trait we used quantitative phylogenetic analyses to test whether brood-covering behavior covaries among attine...... ant clades and with two hygienic traits that reduce risk of disease: mycelial brood cover did not correlate with mutualistic bacteria that the ants culture on their cuticles for their antibiotics, but there was a negative relationship between metapleural gland grooming and mycelial cover. A broader...

The relationship between female brooding and male nestling provisioning: does climate underlie geographic variation in sex roles?

Science.gov (United States)

Yoon, Jongmin; Sofaer, Helen R.; Sillett, T. Scott; Morrison, Scott A.; Ghalambor, Cameron K.

2017-01-01

Comparative studies of populations occupying different environments can provide insights into the ecological conditions affecting differences in parental strategies, including the relative contributions of males and females. Male and female parental strategies reflect the interplay between ecological conditions, the contributions of the social mate, and the needs of offspring. Climate is expected to underlie geographic variation in incubation and brooding behavior, and can thereby affect both the absolute and relative contributions of each sex to other aspects of parental care such as offspring provisioning. However, geographic variation in brooding behavior has received much less attention than variation in incubation attentiveness or provisioning rates. We compared parental behavior during the nestling period in populations of orange-crowned warblers Oreothlypis celata near the northern (64°N) and southern (33°N) boundaries of the breeding range. In Alaska, we found that males were responsible for the majority of food delivery whereas the sexes contributed equally to provisioning in California. Higher male provisioning in Alaska appeared to facilitate a higher proportion of time females spent brooding the nestlings. Surprisingly, differences in brooding between populations could not be explained by variation in ambient temperature, which was similar between populations during the nestling period. While these results represent a single population contrast, they suggest additional hypotheses for the ecological correlates and evolutionary drivers of geographic variation in brooding behavior, and the factors that shape the contributions of each sex.

Transcriptome of the Antarctic brooding gastropod mollusc Margarella antarctica.

Science.gov (United States)

Clark, Melody S; Thorne, Michael A S

2015-12-01

454 RNA-Seq transcriptome data were generated from foot tissue of the Antarctic brooding gastropod mollusc Margarella antarctica. A total of 6195 contigs were assembled de novo, providing a useful resource for researchers with an interest in Antarctic marine species, phylogenetics and mollusc biology, especially shell production. Copyright © 2015 Elsevier B.V. All rights reserved.

Does brood size manipulation affect later competitive behaviour of offspring?

NARCIS (Netherlands)

deKogel, CH

Data from several field experiments support the existence of a trade-off between number and quality of offspring. However, long term effects of brood size on fitness related traits of offspring have been a relatively neglected area of research. In a laboratory experiment the effect of manipulated

GROWTH OF CORMORANT PHALACROCORAX-CARBO-SINENSIS CHICKS IN RELATION TO BROOD SIZE, AGE RANKING AND PARENTAL FISHING EFFORT

NARCIS (Netherlands)

PLATTEEUW, M; KOFFIJBERG, K; DUBBELDAM, W

1995-01-01

Growth parameters of Cormorant hatchlings are described in relation to brood size and age ranking of each chick within individual broods. Growth rates, expressed as body mass increment per day over the period of linear, growth (5-30 days), ranged from 56.4-102.8 g . d(-1) and were found to be

Cytochemistry of fat body trophocytes and ovaries of workers and queens of Melipona quadrifasciata anthidioides (Hymenoptera: Apidae: Meliponini) during vitellogenesis.

Science.gov (United States)

Paes-de-Oliveira, Vagner Tadeu; Roat, Thaisa Cristina; Berger, Bruno; Da Cruz-Landim, Carminda

2012-12-01

The fat body (FB) of insects is where yolk proteins are synthesized. Therefore, relationships between the FB and oogenesis were studied in nurse workers, virgins, and physogastric queens of Melipona quadrifasciata anthidioides, a stingless bee in which the workers produce and lay eggs while provisioning brood cells. The relationships between FB and oogenesis, as well as the routes of materials from hemolymph to the oocytes, were studied through the cytochemical detection of lipids by osmium imidazole (OI), carbohydrates by ruthenium red (RR) and basic proteins by ammoniacal silver (AS). The results show differences in the presence of the studied materials in FB trophocytes and ovary of the classes of females studied and oogenesis phases. Material that tested positive for the treatments was detected among the classes of individuals studied in both, trophocytes and oocytes, and in the route of those materials from hemolymph to the oocytes. The differences found among the individual classes indicate relationships with the nutrition and adaptation to the parsimonious use of nutrients in the metabolism of reproduction. Copyright © 2012 Wiley Periodicals, Inc.

Importance of brood maintenance terms in simple models of the honeybee - Varroa destructor - acute bee paralysis virus complex

Directory of Open Access Journals (Sweden)

Hermann J. Eberl

2010-09-01

Full Text Available We present a simple mathematical model of the infestation of a honeybee colony by the Acute Paralysis Virus, which is carried by parasitic varroa mites (Varroa destructor. This is a system of nonlinear ordinary differential equations for the dependent variables: number of mites that carry the virus, number of healthy bees and number of sick bees. We study this model with a mix of analytical and computational techniques. Our results indicate that, depending on model parameters and initial data, bee colonies in which the virus is present can, over years, function seemingly like healthy colonies before they decline and disappear rapidly (e.g. Colony Collapse Disorder, wintering losses. This is a consequence of the fact that a certain number of worker bees is required in a colony to maintain and care for the brood, in order to ensure continued production of new bees.

Patch size and edge proximity are useful predictors of brood parasitism but not nest survival of grassland birds.

Science.gov (United States)

Benson, Thomas J; Chiavacci, Scott J; Ward, Michael P

2013-06-01

Declines of migratory birds have led to increased focus on causative factors for these declines, including the potential adverse effects of habitat fragmentation on reproductive success. Although numerous studies have addressed how proximity to a habitat edge, patch size, or landscape context influence nest survival or brood parasitism, many have failed to find the purported effects. Furthermore, many have sought to generalize patterns across large geographic areas and habitats. Here, we examined evidence for effects of edge proximity, patch size, and landscape context on nest survival and brood parasitism of grassland birds, a group of conservation concern. The only consistent effect was a positive association between edge proximity and brood parasitism. We examined effects of patch size on nest survival (37 studies) and brood parasitism (30 studies) representing 170 and 97 different estimates, respectively, with a total sample size of > 14000 nests spanning eastern North America. Nest survival weakly increased with patch size in the Great Plains, but not in the Midwestern or Eastern United States, and brood parasitism was inversely related to patch size and consistently greater in the Great Plains. The consistency in brood parasitism relative to nest survival patterns is likely due to parasitism being caused by one species, while nest survival is driven by a diverse and variable suite of nest predators. Often, studies assume that predators responsible for nest predation, the main driver of nest success, either are the same or exhibit the same behaviors across large geographic areas. These results suggest that a better mechanistic understanding of nest predation is needed to provide meaningful conservation recommendations for improving grassland bird productivity, and that the use of general recommendations across large geographic areas should only be undertaken when sufficient data are available from all regions.

Waptia and the Diversification of Brood Care in Early Arthropods.

Science.gov (United States)

Caron, Jean-Bernard; Vannier, Jean

2016-01-11

Brood care, including the carrying of eggs or juveniles, is a form of parental care, which, like other parental traits [1], enhances offspring fitness with variable costs and benefits to the parents [2]. Attempts to understand why and how parental care evolved independently in numerous animal groups often emphasize the role of environmental pressures such as predation, ephemeral resources, and, more generally, the harshness of environment. The fossil record can, in principle, provide minimum age constraints on the evolution of life-history traits, including brood care and key information on the reproductive strategies of extinct organisms. New, exceptionally preserved specimens of the weakly sclerotized arthropod Waptia fieldensis from the middle Cambrian (ca. 508 million years ago) Burgess Shale, Canada, provide the oldest example of in situ eggs with preserved embryos in the fossil record. The relatively small clutch size, up to 24 eggs, and the relatively large diameter of individual eggs, some over 2 mm, contrast with the high number of small eggs-found without preserved embryos-in the bivalved bradoriid arthropod Kunmingella douvillei from the Chengjiang biota (ca. 515 million years ago). The presence of these two different parental strategies suggests a rapid evolution of a variety of modern-type life-history traits, including extended investment in offspring survivorship, soon after the Cambrian emergence of animals. Together with previously described brooded eggs in ostracods from the Upper Ordovician (ca. 450 million years ago), these new findings suggest that the presence of a bivalved carapace played a key role in the early evolution of parental care in arthropods. Copyright © 2016 Elsevier Ltd. All rights reserved.

Partial brood release in woodlice: A bet- hedging tactic?

African Journals Online (AJOL)

1994-06-06

Jun 6, 1994 ... spring survival or reduce Lhe variance in juvenile mortality ... Offspring re- leased in advance of their siblings amounted to around. 30,9% of the total brood and occurred in females with a wide range of size (11,14-31,58 mg) and fertility (8-36 ... limited parental care by the female as it will delay \\he onset.

Impaired Olfactory Associative Behavior of Honeybee Workers Due to Contamination of Imidacloprid in the Larval Stage

Science.gov (United States)

Yang, En-Cheng; Chang, Hui-Chun; Wu, Wen-Yen; Chen, Yu-Wen

2012-01-01

The residue of imidacloprid in the nectar and pollens of the plants is toxic not only to adult honeybees but also the larvae. Our understanding of the risk of imidacloprid to larvae of the honeybees is still in a very early stage. In this study, the capped-brood, pupation and eclosion rates of the honeybee larvae were recorded after treating them directly in the hive with different dosages of imidacloprid. The brood-capped rates of the larvae decreased significantly when the dosages increased from 24 to 8000 ng/larva. However, there were no significant effects of DMSO or 0.4 ng of imidacloprid per larva on the brood-capped, pupation and eclosion rates. Although the sublethal dosage of imidacloprid had no effect on the eclosion rate, we found that the olfactory associative behavior of the adult bees was impaired if they had been treated with 0.04 ng/larva imidacloprid in the larval stage. These results demonstrate that a sublethal dosage of imidacloprid given to the larvae affects the subsequent associative ability of the adult honeybee workers. Thus, a low dose of imidacloprid may affect the survival condition of the entire colony, even though the larvae survive to adulthood. PMID:23166680

Description age-3 brood rainbow trout bred in the conditions of the industral fish farm "Sloboda Banyliv"

Directory of Open Access Journals (Sweden)

P. Mendryshora

2017-06-01

Full Text Available Purpose. To analyze the results of cultivation and give fish-breeding and biological characteristics of age-3 brood rainbow trout grown using industrial technology in the conditions of the trout farm "Sloboda Banyliv." Methodology. Fish cultivation was carried in tank conditions of the trout farm "Sloboda Banyliv". The material for the study were age-3 brood rainbow trout obtained from eggs of the fall-spawning form of rainbow trout. Cultivation was carried out in a 216 m2 tank, stocking density of 255 fish/m2, using standard trout culture methods. Statistical analysis of the material was performed in Microsoft Office Excel (2003. Analysis of the variables was performed in the system of absolute values. The analysis criteria were their mean values mean deviations (M±m, standard error (σ, variability coefficient (Cv. Fish were fed with specialized feed manufactured by “BioMar” (Denmark with a high protein content (more than 40%. Findings. Based on the performed selective-breeding works aimed at creating brood stocks of rainbow trout, it was found that brood fish reared in the industrial conditions of the fish farm “Sloboda Banyliv”, despite instable culture conditions, were characterized by a moderate growth rate and had high values of productive and reproductive features. Mean weight of age-3 rainbow trout females was 1282.5 g, fecundity — 3.48 thousand eggs. Mean weight of produced eggs was 239.17 g, while individual parameters were 70.4 mg for the weight and 4.58 mm for the diameter. Originality. For the first time a study aimed at the formation of brood stocks of rainbow trout with analysis of phenotypic and productive features in the conditions of a fish farm with instable temperature and water regimes has been conducted. Practical value. The results of the performed work will allow selecting and forming a brood stock with high values of productive and reproductive features.

Energy expenditure, nestling age, and brood size : an experimental study of parental behavior in the great tit Parus major

NARCIS (Netherlands)

Sanz, JJ; Tinbergen, JM

1999-01-01

A brood manipulation experiment on great tits Parus major was performed to study the effects of nestling age and brood size on parental care and offspring survival. Daily energy expenditure (DEE) of females feeding nestlings of 6 and 12 days of age was measured using the doubly-labeled water

The dynamics of male brooding, mating patterns, and sex roles in pipefishes and seahorses (family Syngnathidae).

Science.gov (United States)

Wilson, Anthony B; Ahnesjö, Ingrid; Vincent, Amanda C J; Meyer, Axel

2003-06-01

Modern theory predicts that relative parental investment of the sexes in their young is a key factor responsible for sexual selection. Seahorses and pipefishes (family Syngnathidae) are extraordinary among fishes in their remarkable adaptations for paternal care and frequent occurrences of sex-role reversals (i.e., female-female competition for mates), offering exceptional opportunities to test predictions of sexual selection theory. During mating, the female transfers eggs into or onto specialized egg-brooding structures that are located on either the male's abdomen or its tail, where they are osmoregulated, aerated, and nourished by specially adapted structures. All syngnathid males exhibit this form of parental care but the brooding structures vary, ranging from the simple ventral gluing areas of some pipefishes to the completely enclosed pouches found in seahorses. We present a molecular phylogeny that indicates that the diversification of pouch types is positively correlated with the major evolutionary radiation of the group, suggesting that this extreme development and diversification of paternal care may have been an important evolutionary innovation of the Syngnathidae. Based on recent studies that show that the complexity of brooding structures reflects the degree of paternal investment in several syngnathid species, we predicted sex-role reversals to be more common among species with more complex brooding structures. In contrast to this prediction, however, both parsimony- and likelihood-based reconstructions of the evolution of sex-role reversal in pipefishes and seahorses suggest multiple shifts in sex roles in the group, independent from the degree of brood pouch development. At the same time, our data demonstrate that sex-role reversal is positively associated with polygamous mating patterns, whereas most nonreversed species mate monogamously, suggesting that selection for polygamy or monogamy in pipefishes and seahorses may strongly influence sex

Short Note Brood parasitism in the Green-backed Heron ( Butorides ...

African Journals Online (AJOL)

Short Note Brood parasitism in the Green-backed Heron (Butorides striatus). R Yosef, P Zduniak. Abstract. Ostrich 2005, 76(1&2): 78–79. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · http://dx.doi.org/10.2989/00306520509485476 · AJOL African Journals Online.

Brood parasites lay eggs matching the appearance of host clutches

Czech Academy of Sciences Publication Activity Database

Honza, Marcel; Šulc, Michal; Jelínek, Václav; Požgayová, Milica; Procházka, Petr

2014-01-01

Roč. 281, č. 1774 (2014), s. 20132665 ISSN 0962-8452 R&D Projects: GA AV ČR IAA600930903; GA ČR(CZ) GAP506/12/2404 Institutional support: RVO:68081766 Keywords : brood parasitism * cuckoo * egg coloration * egg mimicry * great reed warbler Subject RIV: EG - Zoology Impact factor: 5.051, year: 2014

Subsocial behaviour and brood adoption in mixed-species colonies of two theridiid spiders

Science.gov (United States)

Grinsted, Lena; Agnarsson, Ingi; Bilde, Trine

2012-12-01

Cooperation and group living often evolves through kin selection. However, associations between unrelated organisms, such as different species, can evolve if both parties benefit from the interaction. Group living is rare in spiders, but occurs in cooperative, permanently social spiders, as well as in territorial, colonial spiders. Mixed species spider colonies, involving closely related species, have rarely been documented. We examined social interactions in newly discovered mixed-species colonies of theridiid spiders on Bali, Indonesia. Our aim was to test the degree of intra- and interspecific tolerance, aggression and cooperation through behavioural experiments and examine the potential for adoption of foreign brood. Morphological and genetic analyses confirmed that colonies consisted of two related species Chikunia nigra (O.P. Cambridge, 1880) new combination (previously Chrysso nigra) and a yet undescribed Chikunia sp. Females defended territories and did not engage in cooperative prey capture, but interestingly, both species seemed to provide extended maternal care of young and indiscriminate care for foreign brood. Future studies may reveal whether these species adopt only intra-specific young, or also inter-specifically. We classify both Chikunia species subsocial and intra- and interspecifically colonial, and discuss the evolutionary significance of a system where one or both species may potentially benefit from mutual tolerance and brood adoption.

Conspecific brood parasitism and egg quality in blue tits Cyanistes caeruleus

NARCIS (Netherlands)

Vedder, Oscar; Kingma, Sjouke-Anne; Engelhardt, Nikolaus von; Korsten, Peter; Groothuis, Ton G.G.; Komdeur, Jan

Laying eggs in nests of unrelated conspecific pairs to parasitize their parental care is a common phenomenon in birds. In blue tits Cyanistes caeruleus such conspecific brood parasitism (CBP) has never been reported in the literature. However, in a situation where breeding density was extremely

Maternal androgens in avian brood parasites and their hosts: responses to parasitism and competition?

Science.gov (United States)

Hahn, Caldwell; Wingfield, John C.; Fox, David M.; Walker, Brian G.; Thomley, Jill E

2017-01-01

In the coevolutionary dynamic of avian brood parasites and their hosts, maternal (or transgenerational) effects have rarely been investigated. We examined the potential role of elevated yolk testosterone in eggs of the principal brood parasite in North America, the brown-headed cowbird, and three of its frequent host species. Elevated maternal androgens in eggs are a common maternal effect observed in many avian species when breeding conditions are unfavorable. These steroids accelerate embryo development, shorten incubation period, increase nestling growth rate, and enhance begging vigor, all traits that can increase the survival of offspring. We hypothesized that elevated maternal androgens in host eggs are a defense against brood parasitism. Our second hypothesis was that elevated maternal androgens in cowbird eggs are a defense against intra-specific competition. For host species, we found that elevated yolk testosterone was correlated with parasitized nests of small species, those whose nest success is most reduced by cowbird parasitism. For cowbirds, we found that elevated yolk testosterone was correlated with eggs in multiply-parasitized nests, which indicate intra-specific competition for nests due to high cowbird density. We propose experimental work to further examine the use of maternal effects by cowbirds and their hosts.

Rumination in migraine: Mediating effects of brooding and reflection between migraine and psychological distress

Science.gov (United States)

Kokonyei, Gyongyi; Szabo, Edina; Kocsel, Natalia; Edes, Andrea; Eszlari, Nora; Pap, Dorottya; Magyar, Mate; Kovacs, David; Zsombok, Terezia; Elliott, Rebecca; Anderson, Ian Muir; William Deakin, John Francis; Bagdy, Gyorgy; Juhasz, Gabriella

2016-01-01

Objective: The relationship between migraine and psychological distress has been consistently reported in cross-sectional and longitudinal studies. We hypothesised that a stable tendency to perseverative thoughts such as rumination would mediate the relationship between migraine and psychological distress. Design and Main Outcomes Measures: Self-report questionnaires measuring depressive rumination, current psychological distress and migraine symptoms in two independent European population cohorts, recruited from Budapest (N = 1139) and Manchester (N = 2004), were used. Structural regression analysis within structural equation modelling was applied to test the mediational role of brooding and reflection, the components of rumination, between migraine and psychological distress. Sex, age and lifetime depression were controlled for in the analysis. Results: Migraine predicted higher brooding and reflection scores, and brooding proved to be a mediator between migraine and psychological distress in both samples, while reflection mediated the relationship significantly only in the Budapest sample. Conclusions: Elevated psychological distress in migraine is partially attributed to ruminative response style. Further studies are needed to expand our findings to clinical samples and to examine how rumination links to the adjustment to migraine. PMID:27616579

Sister broods in the spruce bark beetle, Ips typographus (L.)

Czech Academy of Sciences Publication Activity Database

Davídková, Markéta; Doležal, Petr

2017-01-01

Roč. 405, DEC 01 (2017), s. 13-21 ISSN 0378-1127 Grant - others:Lesy ČR(CZ) 08/2009-2015 Institutional support: RVO:60077344 Keywords : re-emergence * sister broods * Ips typographus Subject RIV: EH - Ecology, Behaviour OBOR OECD: Zoology Impact factor: 3.064, year: 2016 http://www.sciencedirect.com/science/article/pii/S0378112717309507

Behavioural and chemical studies of discrimination processes in the leaf-cutting ant Acromyrmex laticeps nigrosetosus (Forel, 1908

Directory of Open Access Journals (Sweden)

D. J. Souza

Full Text Available Leaf-cutting ants live in symbiosis with a basidiomycete fungus that is exploited as a source of nutrients for ant larvae. Tests of brood transport revealed that Acromyrmex laticeps nigrosetosus workers did not discriminate a concolonial brood from an alien brood. The same result was observed with tests of fungus transport. Adult workers showed no aggressive behaviour to workers from other alien colonies (non-nestmates. There was no qualitative variation in the chemical profiles of larvae, pupae and adult workers from the different colonies. However, quantitative differences were observed between the different colonies. Hypotheses about the lack of intraspecific aggression in this subspecies of ants are discussed.

Decommissioning of a hot cell with high levels of contamination. Experience during the Undressed of Workers

International Nuclear Information System (INIS)

Martinez, A.; Sancho, C.

1998-01-01

The object of this work is to show the radiological controls in decommissioning of the inner of the Base Cell of the Nuclear Facility of CIEMAT, IN-04 (Metallurgy Hot Cells) and the experience during the undressed of workers in decommissioning of this cell. The workers were equipped with one cotton overalls and one or two paper overalls of one-use. Also, when the radiation levels are high, the workers were equipped with leaded glasses and aprons. The protection equipment for internal contamination were autonomous and semi-autonomous respiratory equipment. Due to a high superficial contamination levels, two areas were established in order to proceed to the undressed of the workers when these concluded their work. The first area was a confined enclosure by joined to the hot cell, where an expert of the Radiation Protection Service (RPS), trained for it, take off the first paper overall and the first pair of gloves to the worker that come out the hot cells. The second area was at the exist of the Load Zone, where another expert of PRS, take off the second paper overall, the second pair of gloves and dislocated the pipe of air of the semi-autonomous respiratory equipment, to the worker that come out this zone. (Author)

Cell Phones in support of Community Health Workers | CRDI ...

International Development Research Centre (IDRC) Digital Library (Canada)

Cell Phones in support of Community Health Workers ... the diagnosis and treatment of childhood pneumonia at a level 4 health centre (county level). Oximetry is a non-invasive method of monitoring the amount of oxygen in the patient's blood.

Fungi infection in honeybee hives in regions affected by Brazilian sac brood

Directory of Open Access Journals (Sweden)

K.M. Keller

2014-10-01

Full Text Available The Brazilian Sac Brood is a disease that affects apiaries of Africanized bee hives in Brazil, thereby making them susceptible to high losses. This study investigated the pathogenicity of Africanized bee hives by the entomopathogenic fungi in a Brazilian Sac Brood endemic region. The degree of fungal contamination, presence of mycotoxins in beehive elements, and vulnerability of healthy beehives in environments subjected and not subjected to the disease were investigated. From the contaminating fungal load, species that are mycotoxin producers and pathogenic causing mortality in the bees have been isolated. The analysis of bee pollen and bee bread samples did not show the presence of the toxic pollen of Stryphnodendron (Fabaceae, which has been indicated as the causative agent of mortality in pre-pupal stage larvae. However, bee bread showed the highest correlation between substrate and fungal contamination.

Reproductive biology of varroa mites in colonies of Africanized honey bees

NARCIS (Netherlands)

Calderon Fallas, R.A.

2009-01-01

We investigated the reproductive biology of V. destructor in Africanized honeybees (AHB) in Central American conditions, specifically in Costa Rica. Attention was paid to mite fertility and production of viable female mites in worker and drone brood cells. Other reproduction parameters, like

Effects of brood pheromone (SuperBoost) on consumption of protein supplement and growth of honey bee (Hymenoptera: Apidae) colonies during fall in a northern temperate climate.

Science.gov (United States)

Sagili, Ramesh R; Breece, Carolyn R

2012-08-01

Honey bee, Apis mellifera L. (Hymenoptera: Apidae), nutrition is vital for colony growth and maintenance of a robust immune system. Brood rearing in honey bee colonies is highly dependent on protein availability. Beekeepers in general provide protein supplement to colonies during periods of pollen dearth. Honey bee brood pheromone is a blend of methyl and ethyl fatty acid esters extractable from cuticle of honey bee larvae that communicates the presence of larvae in a colony. Honey bee brood pheromone has been shown to increase protein supplement consumption and growth of honey bee colonies in a subtropical winter climate. Here, we tested the hypothesis that synthetic brood pheromone (SuperBoost) has the potential to increase protein supplement consumption during fall in a temperate climate and thus increase colony growth. The experiments were conducted in two locations in Oregon during September and October 2009. In both the experiments, colonies receiving brood pheromone treatment consumed significantly higher protein supplement and had greater brood area and adult bees than controls. Results from this study suggest that synthetic brood pheromone may be used to stimulate honey bee colony growth by stimulating protein supplement consumption during fall in a northern temperate climate, when majority of the beekeepers feed protein supplement to their colonies.

Brood pheromone effects on colony protein supplement consumption and growth in the honey bee (Hymenoptera: Apidae) in a subtropical winter climate.

Science.gov (United States)

Pankiw, Tanya; Sagili, Ramesh R; Metz, Bradley N

2008-12-01

Fatty acid esters extractable from the surface of honey bee, Apis mellifera L. (Hymenoptera: Apidae), larvae, called brood pheromone, significantly increase rate of colony growth in the spring and summer when flowering plant pollen is available in the foraging environment. Increased colony growth rate occurs as a consequence of increased pollen intake through mechanisms such as increasing number of pollen foragers and pollen load weights returned. Here, we tested the hypothesis that addition of brood pheromone during the winter pollen dearth period of a humid subtropical climate increases rate of colony growth in colonies provisioned with a protein supplement. Experiments were conducted in late winter (9 February-9 March 2004) and mid-winter (19 January-8 February 2005). In both years, increased brood area, number of bees, and amount of protein supplement consumption were significantly greater in colonies receiving daily treatments of brood pheromone versus control colonies. Amount of extractable protein from hypopharyngeal glands measured in 2005 was significantly greater in bees from pheromone-treated colonies. These results suggest that brood pheromone may be used as a tool to stimulate colony growth in the southern subtropical areas of the United States where the package bee industry is centered and a large proportion of migratory colonies are overwintered.

Productive characteristics of age-3 brood brown trout (Salmo trutta reared in the conditions industrial aquaculture

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L. Haloyan

2017-03-01

Full Text Available Purpose. Study and analysis of productive and reproductive parameters of brood brown trout reared in the conditions of industrial aquaculture with the use of feeding with specialized artificial feeds. Methodology. Fish rearing was performed using a technology traditional for rainbow trout. Biological evaluation of fish was performed on live material according to the scheme developed by I.F. Pravdin (1966 for salmonids. Fish were anesthetized with “Propiscin”. Metric parameters were measured with the aid of a ruler and caliper. Fish weight was determined on electronic balances. Eggs were preserved in a 4% formalin solution, weight of individual eggs was determined with the aid of torsion balances, egg diameter with a caliper. The duration of spermatozoid motility in males was determined under a microscope under 10X40 magnification with the aid of a stopwatch, sperm concentration was determined in a Goriaev chamber. Multiple regression analysis was performed in JMP IN 4 (SAS Institute. The factor was considered significant if р <0.05. Findings. Brood brown trout reared on specialized artificial feeds had following productive parameters: mean body weight of age-3 fish was 458 g in males and 453 g in females. Mean working fecundity of age-3 fish as 1847 eggs, mean relative working fecundity was 3971 eggs, the mean qualitative parameters of which were: weight of 61.5 g, diameter of 74.7 mm. The reproductive characteristics of age-3 males was high – mean fecundity was 1391 million sperm cells, their motility was 35 sec. Originality. For the first time we reared a stock of brood brown trout in industrial conditions with the use of feeding with specialized artificial feeds. Practical value. The obtained results are a component of the development of a complex technology of salmonid fish rearing with an objective to broad the assortment of valuable gourmet products and to justify the measures on artificial reproduction of brown trout in rivers of

Intrinsic worker mortality depends on behavioral caste and the queens' presence in a social insect

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Kohlmeier, Philip; Negroni, Matteo Antoine; Kever, Marion; Emmling, Stefanie; Stypa, Heike; Feldmeyer, Barbara; Foitzik, Susanne

2017-04-01

According to the classic life history theory, selection for longevity depends on age-dependant extrinsic mortality and fecundity. In social insects, the common life history trade-off between fecundity and longevity appears to be reversed, as the most fecund individual, the queen, often exceeds workers in lifespan several fold. But does fecundity directly affect intrinsic mortality also in social insect workers? And what is the effect of task on worker mortality? Here, we studied how social environment and behavioral caste affect intrinsic mortality of ant workers. We compared worker survival between queenless and queenright Temnothorax longispinosus nests and demonstrate that workers survive longer under the queens' absence. Temnothorax ant workers fight over reproduction when the queen is absent and dominant workers lay eggs. Worker fertility might therefore increase lifespan, possibly due to a positive physiological link between fecundity and longevity, or better care for fertile workers. In social insects, division of labor among workers is age-dependant with young workers caring for the brood and old ones going out to forage. We therefore expected nurses to survive longer than foragers, which is what we found. Surprisingly, inactive inside workers showed a lower survival than nurses but comparable to that of foragers. The reduced longevity of inactive workers could be due to them being older than the nurses, or due to a positive effect of activity on lifespan. Overall, our study points to behavioral caste-dependent intrinsic mortality rates and a positive association between fertility and longevity not only in queens but also in ant workers.

Habitat edge, land management, and rates of brood parasitism in tallgrass prairie.

Science.gov (United States)

Patten, Michael A; Shochat, Eyal; Reinking, Dan L; Wolfe, Donald H; Sherrod, Steve K

2006-04-01

Bird populations in North America's grasslands have declined sharply in recent decades. These declines are traceable, in large part, to habitat loss, but management of tallgrass prairie also has an impact. An indirect source of decline potentially associated with management is brood parasitism by the Brown-headed Cowbird (Molothrus ater), which has had substantial negative impacts on many passerine hosts. Using a novel application of regression trees, we analyzed an extensive five-year set of nest data to test how management of tallgrass prairie affected rates of brood parasitism. We examined seven landscape features that may have been associated with parasitism: presence of edge, burning, or grazing, and distance of the nest from woody vegetation, water, roads, or fences. All five grassland passerines that we included in the analyses exhibited evidence of an edge effect: the Grasshopper Sparrow (Ammodramus savannarum), Henslow's Sparrow (A. henslowii), Dickcissel (Spiza americana), Red-winged Blackbird (Agelaius phoeniceus), and Eastern Meadowlark (Sturnella magna). The edge was represented by narrow strips of woody vegetation occurring along roadsides cut through tallgrass prairie. The sparrows avoided nesting along these woody edges, whereas the other three species experienced significantly higher (1.9-5.3x) rates of parasitism along edges than in prairie. The edge effect could be related directly to increase in parasitism rate with decreased distance from woody vegetation. After accounting for edge effect in these three species, we found evidence for significantly higher (2.5-10.5x) rates of parasitism in grazed plots, particularly those burned in spring to increase forage, than in undisturbed prairie. Regression tree analysis proved to be an important tool for hierarchically parsing various landscape features that affect parasitism rates. We conclude that, on the Great Plains, rates of brood parasitism are strongly associated with relatively recent road cuts

Development and Application of ANN Model for Worker Assignment into Virtual Cells of Large Sized Configurations

International Nuclear Information System (INIS)

Murali, R. V.; Fathi, Khalid; Puri, A. B.

2010-01-01

This paper presents an extended version of study already undertaken on development of an artificial neural networks (ANNs) model for assigning workforce into virtual cells under virtual cellular manufacturing systems (VCMS) environments. Previously, the same authors have introduced this concept and applied it to virtual cells of two-cell configuration and the results demonstrated that ANNs could be a worth applying tool for carrying out workforce assignments. In this attempt, three-cell configurations problems are considered for worker assignment task. Virtual cells are formed under dual resource constraint (DRC) context in which the number of available workers is less than the total number of machines available. Since worker assignment tasks are quite non-linear and highly dynamic in nature under varying inputs and conditions and, in parallel, ANNs have the ability to model complex relationships between inputs and outputs and find similar patterns effectively, an attempt was earlier made to employ ANNs into the above task. In this paper, the multilayered perceptron with feed forward (MLP-FF) neural network model has been reused for worker assignment tasks of three-cell configurations under DRC context and its performance at different time periods has been analyzed. The previously proposed worker assignment model has been reconfigured and cell formation solutions available for three-cell configuration in the literature are used in combination to generate datasets for training ANNs framework. Finally, results of the study have been presented and discussed.

Effect of Brood Pheromone on Survival and Nutrient Intake of African Honey Bees (Apis mellifera scutellata) under Controlled Conditions.

Science.gov (United States)

Démares, Fabien J; Yusuf, Abdullahi A; Nicolson, Susan W; Pirk, Christian W W

2017-05-01

The influence of pheromones on insect physiology and behavior has been thoroughly reported for numerous aspects, such as attraction, gland development, aggregation, mate and kin recognition. Brood pheromone (BP) is released by honey bee larvae to indicate their protein requirements to the colony. Although BP is known to modulate pollen and protein consumption, which in turn can affect physiological and morphological parameters, such as hypopharyngeal gland (HPG) development and ovarian activation, few studies have focused on the effect of BP on nutritional balance. In this study, we exposed newly emerged worker bees for 14 d and found that BP exposure increased protein intake during the first few days, with a peak in consumption at day four following exposure. BP exposure decreased survival of caged honey bees, but did not affect either the size of the HPG acini or ovarian activation stage. The uncoupling of the BP releaser effect, facilitated by working under controlled conditions, and the presence of larvae as stimulating cues are discussed.

Resource selection during brood-rearing by Greater Sage-Grouse [chapter 12

Science.gov (United States)

Nicholas W. Kaczor; Katie M. Herman-Brunson; Kent C. Jensen; Mark A. Rumble; Robert W. Klaver; Christopher C. Swanson

2011-01-01

Understanding population dynamics and resource selection is crucial in developing wildlife resource management plans for sensitive species such as Greater Sage-Grouse (Centrocercus urophasianus). Little is known about sage grouse habitats on the eastern edge of their range. We investigated resource selection of Greater Sage-Grouse during brood- rearing in North and...

Micronuclei in epithelial cells from sputum of uranium workers

International Nuclear Information System (INIS)

Loomis, D.P.; Shy, C.M.; Allen, J.W.; Saccomanno, G.

1990-01-01

The exfoliated-cell micronucleus (MN) assay was used to assess cytogenetic effects of exposure to radon progeny and cigarette smoke among 99 Colorado plateau uranium workers. Subjects were selected at random from employees in underground and open-pit uranium mines, ore mills, laboratories, and offices participating in a sputum screening program from 1964-88. The prevalence of cells with MN was determined by scoring one sputum specimen for each worker. Data obtained by interview were used to classify exposure to radon progeny and smoking at the time sputum specimens were taken. Underground miners were considered exposed to radon progeny, and others were considered unexposed. Neither radon progeny exposure nor cigarette smoking had any appreciable effect on the prevalence of cells with MN; crude prevalence ratios were 1.0 (95% CI 0.7-1.4) and 0.9 (95% CE 0.6-1.3), respectively. The effects of radon and smoking were not confounded by each other or by age, and there was no evidence of synergy between exposures. The findings appear to cast doubt on the epidemiological utility of a sputum-based MN assay for studies of other populations exposed to occupational or environmental lung carcinogens

Vertical organization of the division of labor within nests of the Florida harvester ant, Pogonomyrmex badius.

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Walter R Tschinkel

Full Text Available In the Florida harvester ant, Pogonomyrmex badius, foragers occur only in the top 15 cm of the nest, whereas brood and brood-care workers reside mostly in the deepest regions, yet the food and seeds foragers collect must be transported downward 30 to 80 cm to seed chambers and up to 2 m to brood chambers. Using mark-recapture techniques with fluorescent printer's ink, we identified a class of workers that ranges widely within the vertical structure of the nest, rapidly moving materials dropped by foragers in the upper regions downward, and excavated soil from deeper upward. Within the nest, only 5% of foragers were recovered below 20 cm depth, but about 30% of transfer workers and 82% of unmarked workers were found there. Below 70 cm depth, 90% of workers were unmarked, and were probably involved mostly in brood care. During the summer, the transfer workers comprise about a quarter of the nest population, while foragers make up about 40%. Workers marked as transfer workers later appear as foragers, while those marked as foragers die and disappear from the foraging population, suggesting that transfer workers are younger, and age into foraging. The importance of these findings for laboratory studies of division of labor are discussed. The efficient allocation of labor is a key component of superorganismal fitness.

Immune cells in Chernobyl recovery operation workers exposed over 500 mSv

International Nuclear Information System (INIS)

Bazyka, D.; Byelyaeva, N.; Chumak, A.; Golyarnik, N.; Maznichenko, O.; Kovalenko, Ju.

2004-01-01

Immune response parameters were studied in Chernobyl radiation emergency workers exposed to radiation over 500 mSv during 1986. Initial response stage to the radiation exposure was characterised by immunological deficiency with T-cell subsets changes. In the reconstitution period inhibition of immune function was associated with lymphocyte subset changes such as decreased CD3 + and CD4 + cell counts and increased number of somatic mutations in TCR-locus. Late period after the acute radiation exposure in Chernobyl radiation emergency workers is characterized by decreased CD8 + suppressor cell function that could lead to poor proliferation control. Subset analysis of CD34 + cells showed in ARS survivors counts significantly higher than in control especially for the most primitive progenitors with CD34 + CD90 + CD45 -/l ow and CD34 + CD45 - CD38 - phenotypes. (author)

Destructive disinfection of infected brood prevents systemic disease spread in ant colonies.

Science.gov (United States)

Pull, Christopher D; Ugelvig, Line V; Wiesenhofer, Florian; Grasse, Anna V; Tragust, Simon; Schmitt, Thomas; Brown, Mark Jf; Cremer, Sylvia

2018-01-09

In social groups, infections have the potential to spread rapidly and cause disease outbreaks. Here, we show that in a social insect, the ant Lasius neglectus , the negative consequences of fungal infections ( Metarhizium brunneum ) can be mitigated by employing an efficient multicomponent behaviour, termed destructive disinfection, which prevents further spread of the disease through the colony. Ants specifically target infected pupae during the pathogen's non-contagious incubation period, utilising chemical 'sickness cues' emitted by pupae. They then remove the pupal cocoon, perforate its cuticle and administer antimicrobial poison, which enters the body and prevents pathogen replication from the inside out. Like the immune system of a metazoan body that specifically targets and eliminates infected cells, ants destroy infected brood to stop the pathogen completing its lifecycle, thus protecting the rest of the colony. Hence, in an analogous fashion, the same principles of disease defence apply at different levels of biological organisation.

Inconvenientes y beneficios del comportamiento higiénico de la abeja de la miel (Apis mellifera L.)

NARCIS (Netherlands)

Leclercq, Gil; Pannebakker, Bart; Gengler, Nicolas; Nguyen, Bach Kim; Francis, Frédéric

2017-01-01

The hygienic behavior of honey bee workers contributes to the social immunity of colonies. The ability of workers to detect and remove unhealthy or dead brood prevents the transmission of brood diseases inside the colony. Over the last five decades, this trait has been extensively studied and

Estimation of radiation exposure for hot cell workers during DUPIC fuel fabrication process in IMEF M6 cell

Energy Technology Data Exchange (ETDEWEB)

Jeon, Yong Bum; Baek, Sang Yeol; Park, Dae Kyu

1997-06-01

DUPIC(Direct Use of spent PWR fuel In CANDU) fuel cycle to utilize the PWR spent fuel in fabricating CANDU fuel, which is expected to reduce not only the total amount of high level radwastes but the energy sources is underway. IMEF M6 cell to be used as DUPIC fuel fabrication facility is refurbished and retrofitted. Radiation exposure for the hot cell worker by dispersion of the radioactive materials during the DUPIC process were estimated on the basis of the hot cell design information. According to the estimation results, DUPIC fuel fabrication process could be run without any severe impacts to the hot cell workers when the ventilation system to maintain the sufficient pressure difference between hotcell and working area and radiation monitoring system is supports the hot cell operation properly. (author). 4 tabs., 6 figs.

Declining Brown-headed Cowbird (Molothrus ater populations are associated with landscape-specific reductions in brood parasitism and increases in songbird productivity.

Directory of Open Access Journals (Sweden)

W Andrew Cox

Full Text Available Many songbird species have experienced significant population declines, partly because of brood parasitism by the Brown-headed Cowbird (Molothrus ater, which is positively associated with increasing landscape forest cover in the midwestern United States. However, cowbirds are also experiencing long-term population declines, which should reduce parasitism pressure and thus increase productivity of host species. We used 20 years of nest monitoring data from five sites in Missouri across a gradient of landscape forest cover to assess temporal trends in the rate and intensity of brood parasitism for Acadian Flycatchers (Empidonax virescens, Indigo Buntings (Passerina cyanea, and Northern Cardinals (Cardinalis cardinalis. We evaluated whether there were concomitant changes in fledging brood size, nest survival, a combination of the two metrics (i.e., host young produced per nest attempt, and whether such changes were more substantial with decreasing landscape forest cover. Parasitism rates and intensities declined substantially during 1991-2010. Fledging brood size and nest survival rates were positively associated with landscape forest cover, confirming the fragmentation hypothesis for Midwest forest birds. Declining parasitism rates were associated with increased fledging brood sizes, with more pronounced increases as landscape forest cover decreased. Nest survival increased insubstantially across time during laying and incubation, but not during the nestling stage. The best predictor of nest survival was parasitism status, with parasitized nests surviving at lower rates than unparasitized nests. Overall, productivity increased during 1991-2010, with more pronounced increases associated with lower levels of landscape forest cover. The negative effects of cowbirds on nest survival in addition to fledging brood size in less forested landscapes suggest that cowbirds may be a primary cause of forest fragmentation effects on songbird productivity in the

Social regulation of maternal traits in nest-founding bumble bee (Bombus terrestris) queens.

Science.gov (United States)

Woodard, S Hollis; Bloch, Guy; Band, Mark R; Robinson, Gene E

2013-09-15

During the nest-founding phase of the bumble bee colony cycle, queens undergo striking changes in maternal care behavior. Early in the founding phase, prior to the emergence of workers in the nest, queens are reproductive and also provision and feed their offspring. However, later in the founding phase, queens reduce their feeding of larvae and become specialized on reproduction. This transition is synchronized with the emergence of workers in the colony, who assume the task of feeding their siblings. Using a social manipulation experiment with the bumble bee Bombus terrestris, we tested the hypothesis that workers regulate the transition from feeding brood to specialization on reproduction in nest-founding bumble bee queens. Consistent with this hypothesis, we found that early-stage nest-founding queens with workers prematurely added to their nests reduce their brood-feeding behavior and increase egg laying, and likewise, late-stage nest-founding queens increase their brood-feeding behavior and decrease egg-laying when workers are removed from their nests. Further, brood-feeding and egg-laying behaviors were negatively correlated. We used Agilent microarrays designed from B. terrestris brain expressed sequenced tags (ESTs) to explore a second hypothesis, that workers alter brain gene expression in nest-founding queens. We found evidence that brain gene expression in nest-founding queens is altered by the presence of workers, with the effect being much stronger in late-stage founding queens. This study provides new insights into how the transition from feeding brood to specialization on reproduction in queen bumble bees is regulated during the nest initiation phase of the colony cycle.

Social context and reproductive potential affect worker reproductive decisions in a eusocial insect.

Directory of Open Access Journals (Sweden)

Boris Yagound

Full Text Available Context-dependent decision-making conditions individual plasticity and is an integrant part of alternative reproductive strategies. In eusocial Hymenoptera (ants, bees and wasps, the discovery of worker reproductive parasitism recently challenged the view of workers as a homogeneous collective entity and stressed the need to consider them as autonomous units capable of elaborate choices which influence their fitness returns. The reproductive decisions of individual workers thus need to be investigated and taken into account to understand the regulation of reproduction in insect societies. However, we know virtually nothing about the proximate mechanisms at the basis of worker reproductive decisions. Here, we test the hypothesis that the capacity of workers to reproduce in foreign colonies lies in their ability to react differently according to the colonial context and whether this reaction is influenced by a particular internal state. Using the bumble bee Bombus terrestris, we show that workers exhibit an extremely high reproductive plasticity which is conditioned by the social context they experience. Fertile workers reintroduced into their mother colony reverted to sterility, as expected. On the contrary, a high level of ovary activity persisted in fertile workers introduced into a foreign nest, and this despite more frequent direct contacts with the queen and the brood than control workers. Foreign workers' reproductive decisions were not affected by the resident queen, their level of fertility being similar whether or not the queen was removed from the host colony. Workers' physiological state at the time of introduction is also of crucial importance, since infertile workers failed to develop a reproductive phenotype in a foreign nest. Therefore, both internal and environmental factors appear to condition individual reproductive strategies in this species, suggesting that more complex decision-making mechanisms are involved in the regulation

Lower virus infections in Varroa destructor-infested and uninfested brood and adult honey bees (Apis mellifera) of a low mite population growth colony compared to a high mite population growth colony.

Science.gov (United States)

Emsen, Berna; Hamiduzzaman, Mollah Md; Goodwin, Paul H; Guzman-Novoa, Ernesto

2015-01-01

A comparison was made of the prevalence and relative quantification of deformed wing virus (DWV), Israeli acute paralysis virus (IAPV), black queen cell virus (BQCV), Kashmir bee virus (KBV), acute bee paralysis virus (ABPV) and sac brood virus (SBV) in brood and adult honey bees (Apis mellifera) from colonies selected for high (HMP) and low (LMP) Varroa destructor mite population growth. Two viruses, ABPV and SBV, were never detected. For adults without mite infestation, DWV, IAPV, BQCV and KBV were detected in the HMP colony; however, only BQCV was detected in the LMP colony but at similar levels as in the HMP colony. With mite infestation, the four viruses were detected in adults of the HMP colony but all at higher amounts than in the LMP colony. For brood without mite infestation, DWV and IAPV were detected in the HMP colony, but no viruses were detected in the LMP colony. With mite infestation of brood, the four viruses were detected in the HMP colony, but only DWV and IAPV were detected and at lower amounts in the LMP colony. An epidemiological explanation for these results is that pre-experiment differences in virus presence and levels existed between the HMP and LMP colonies. It is also possible that low V. destructor population growth in the LMP colony resulted in the bees being less exposed to the mite and thus less likely to have virus infections. LMP and HMP bees may have also differed in susceptibility to virus infection.

Micronucleus Assay in Exfoliated Buccal Epithelial Cells Using Liquid Based Cytology Preparations in Building Construction Workers.

Science.gov (United States)

Arul, P; Smitha, Shetty; Masilamani, Suresh; Akshatha, C

2018-01-01

Cytogenetic damage in exfoliated buccal epithelial cells due to environmental and occupational exposure is often monitored by micronucleus (MN) assay using liquid based cytology (LBC) preparations. This study was performed to evaluate MN in exfoliated buccal epithelial cells of building construction workers using LBC preparations. LBC preparations of exfoliated buccal epithelial cells from 100 subjects [50 building construction workers (cases) and 50 administrative staffs (controls)] was evaluated by May-Grunwald Giemsa, Hematoxylin and Eosin and Papanicolaou stains. Student's t test was used for statistical analysis and a P value of 5 years) and smokers and non-smokers of cases (P=0.001). However, there were meaningful differences regarding mean frequencies of MN between smokers, non-smokers, those with alcohol consumption or not in cases and controls using various stains (P=0.001). There was an increased risk of cytogenetic damage in building construction workers. However, evaluation of MN of exfoliated buccal epithelial cells in building construction workers serve as a minimally invasive biomarker for cytogenetic damage. LBC preparations can be applied for MN assay as it improves the quality of smears and cell morphology, decreases the confounding factors and reduces false positive results.

Circatrigintan instead of lunar periodicity of larval release in a brooding coral species.

Science.gov (United States)

Linden, Bart; Huisman, Jef; Rinkevich, Baruch

2018-04-04

Larval release by brooding corals is often assumed to display lunar periodicity. Here, we show that larval release of individual Stylophora pistillata colonies does not comply with the assumed tight entrainment by the lunar cycle, and can better be classified as a circatrigintan pattern. The colonies exhibited three distinct reproductive patterns, characterized by short intervals, long intervals and no periodicity between reproductive peaks, respectively. Cross correlation between the lunar cycle and larval release of the periodic colonies revealed an approximately 30-day periodicity with a variable lag of 5 to 10 days after full moon. The observed variability indicates that the lunar cycle does not provide a strict zeitgeber. Other factors such as water temperature and solar radiation did not correlate significantly with the larval release. The circatrigintan patterns displayed by S. pistillata supports the plasticity of corals and sheds new light on discussions on the fecundity of brooding coral species.

Automatic Observer Script for StarCraft: Brood War Bot Games (technical report)

OpenAIRE

Mattsson, Björn Persson; Vajda, Tomáš; Čertický, Michal

2015-01-01

This short report describes an automated BWAPI-based script developed for live streams of a StarCraft Brood War bot tournament, SSCAIT. The script controls the in-game camera in order to follow the relevant events and improve the viewer experience. We enumerate its novel features and provide a few implementation notes.

Tests of landscape influence: nest predation and brood parasitism in fragmented ecosystems

Science.gov (United States)

Joshua J. Tewksbury; Lindy Garner; Shannon H. Garner; John D. Lloyd; Victoria A. Saab; Thomas E. Martin

2006-01-01

The effects of landscape fragmentation on nest predation and brood parasitism, the two primary causes of avian reproductive failure, have been difficult to generalize across landscapes, yet few studies have clearly considered the context and spatial scale of fragmentation. Working in two river systems fragmented by agricultural and rural-housing development, we tracked...

Early life stress predicts negative urgency through brooding, depending on 5-HTTLPR genotype: A pilot study with 6-month follow-up examining suicide ideation.

Science.gov (United States)

Valderrama, Jorge; Miranda, Regina

2017-12-01

The present study examined the interaction between early life stress and 5-HTT genotypes in predicting two risk factors for suicidal behavior - the brooding subtype of rumination and impulsivity, in the form of negative urgency - over time. Furthermore, we examined early life stress, brooding, and impulsivity as predictors of suicidal ideation over time. Participants with and without a history of early life stress were genotyped for the 5-HTTLPR polymorphism and completed assessments assessing brooding and negative urgency at baseline and 6-month follow up. Early life emotional abuse was associated with negative urgency at follow-up. We found an indirect effect of early life emotional abuse on negative urgency through brooding among individuals with 5-HTT low expressing genotypes but not among individuals with 5-HTT high expressing genotypes. Further, a logistic regression analysis revealed that negative urgency was associated with higher odds (O.R. = 16.2) of reporting suicide ideation (versus no ideation) at follow-up. Our findings suggest that brooding and negative urgency may result from the interaction between early life emotional abuse and 5-HTT low expressing genotypes. Further research is necessary to understand how early life stress interacts with 5-HTT genotypes to confer risk for suicidal behavior through psychological mechanisms. Copyright © 2017 Elsevier B.V. All rights reserved.

SEASONAL-VARIATION IN THE SEX-RATIO OF MARSH HARRIER CIRCUS-AERUGINOSUS BROODS

NARCIS (Netherlands)

ZIJLSTRA, M; DAAN, S; BRUINENBERGRINSMA, J

1992-01-01

1. Analysis of the sexes of 2260 nestlings in 735 marsh harrier broods revealed an overall excess [sex ratio (SR) = 54.8%] of males, and a significant increase in the proportion of males with progressive laying date (d = day of the year): In [SR/(1-SR)] = -1.286 + 0.013 d. 2. We argue that it is

Effects of brood size manipulation and common origin on phenotype and telomere length in nestling collared flycatchers

Directory of Open Access Journals (Sweden)

Voillemot Marie

2012-08-01

Full Text Available Abstract Background Evidence is accumulating that telomere length is a good predictor of life expectancy, especially early in life, thus calling for determining the factors that affect telomere length at this stage. Here, we investigated the relative influence of early growth conditions and origin (genetics and early maternal effects on telomere length of collared flycatchers (Ficedula albicollis at fledging. We experimentally transferred hatchlings among brood triplets to create reduced, control (i.e. unchanged final nestling number and enlarged broods. Results Although our treatment significantly affected body mass at fledging, we found no evidence that increased sibling competition affected nestling tarsus length and telomere length. However, mixed models showed that brood triplets explained a significant part of the variance in body mass (18% and telomere length (19%, but not tarsus length (13%, emphasizing that unmanipulated early environmental factors influenced telomere length. These models also revealed low, but significant, heritability of telomere length (h2 = 0.09. For comparison, the heritability of nestling body mass and tarsus length was 0.36 and 0.39, respectively, which was in the range of previously published estimates for those two traits in this species. Conclusion Those findings in a wild bird population demonstrate that telomere length at the end of the growth period is weakly, but significantly, determined by genetic and/or maternal factors taking place before hatching. However, we found no evidence that the brood size manipulation experiment, and by extension the early growth conditions, influenced nestling telomere length. The weak heritability of telomere length suggests a close association with fitness in natural populations.

Growth strategies of passerine birds are related to brood parasitism by the brown-headed cowbird (Molothrus ater).

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Remes, Vladimír

2006-08-01

Sibling competition was proposed as an important selective agent in the evolution of growth and development. Brood parasitism by the brown-headed cowbird (Molothrus ater) intensifies sibling competition in the nests of its hosts by increasing host chick mortality and exposing them to a genetically unrelated nestmate. Intranest sibling competition for resources supplied by parents is size dependent. Thus, it should select for high development rates and short nestling periods, which would alleviate negative impacts of brood parasitic chicks on host young. I tested these predictions on 134 North American passerines by comparative analyses. After controlling for covariates and phylogeny, I showed that high parasitism rate was associated with higher nestling growth rate, lower mass at fledging, and shorter nestling periods. These effects were most pronounced in species in which sibling competition is most intense (i.e., weighing over about 30 g). When species were categorized as nonhosts versus old hosts (parasitized for thousands of years) versus new hosts (parasitized the last 100-200 years), there was a clear effect of this parasitism category on growth strategies. Nestling growth rate was the most evolutionarily flexible trait, followed by mass at fledging and nestling period duration. Adjustments during incubation (incubation period length, egg volume) were less pronounced and generally disappeared after controlling for phylogeny. I show that sibling competition caused by brood parasites can have strong effects on the evolution of host growth strategies and that the evolution of developmental traits can take place very rapidly. Human alteration of habitats causing spread of brood parasites to new areas thus cascades into affecting the evolution of life-history traits in host species.

Success of cuckoo catfish brood parasitism reflects coevolutionary history and individual experience of their cichlid hosts

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Polačik, Matej; Smith, Carl; Honza, Marcel; Reichard, Martin

2018-01-01

Obligate brood parasites manipulate other species into raising their offspring. Avian and insect brood parasitic systems demonstrate how interacting species engage in reciprocal coevolutionary arms races through behavioral and morphological adaptations and counteradaptations. Mouthbrooding cichlid fishes are renowned for their remarkable evolutionary radiations and complex behaviors. In Lake Tanganyika, mouthbrooding cichlids are exploited by the only obligate nonavian vertebrate brood parasite, the cuckoo catfish Synodontis multipunctatus. We show that coevolutionary history and individual learning both have a major impact on the success of cuckoo catfish parasitism between coevolved sympatric and evolutionarily naïve allopatric cichlid species. The rate of cuckoo catfish parasitism in coevolved Tanganyikan hosts was 3 to 11 times lower than in evolutionarily naïve cichlids. Moreover, using experimental infections, we demonstrate that parasite egg rejection in sympatric hosts was much higher, leading to seven times greater parasite survival in evolutionarily naïve than sympatric hosts. However, a high rejection frequency of parasitic catfish eggs by coevolved sympatric hosts came at a cost of increased rejection of their own eggs. A significant cost of catfish parasitism was universal, except for coevolved sympatric cichlid species with previous experience of catfish parasitism, demonstrating that learning and individual experience both contribute to a successful host response.

Brood ball-mediated transmission of microbiome members in the dung beetle, Onthophagus taurus (Coleoptera: Scarabaeidae.

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Anne M Estes

Full Text Available Insects feeding on plant sap, blood, and other nutritionally incomplete diets are typically associated with mutualistic bacteria that supplement missing nutrients. Herbivorous mammal dung contains more than 86% cellulose and lacks amino acids essential for insect development and reproduction. Yet one of the most ecologically necessary and evolutionarily successful groups of beetles, the dung beetles (Scarabaeinae feeds primarily, or exclusively, on dung. These associations suggest that dung beetles may benefit from mutualistic bacteria that provide nutrients missing from dung. The nesting behaviors of the female parent and the feeding behaviors of the larvae suggest that a microbiome could be vertically transmitted from the parental female to her offspring through the brood ball. Using sterile rearing and a combination of molecular and culture-based techniques, we examine transmission of the microbiome in the bull-headed dung beetle, Onthophagus taurus. Beetles were reared on autoclaved dung and the microbiome was characterized across development. A ~1425 bp region of the 16S rRNA identified Pseudomonadaceae, Enterobacteriaceae, and Comamonadaceae as the most common bacterial families across all life stages and populations, including cultured isolates from the 3(rd instar digestive system. Finer level phylotyping analyses based on lepA and gyrB amplicons of cultured isolates placed the isolates closest to Enterobacter cloacae, Providencia stuartii, Pusillimonas sp., Pedobacter heparinus, and Lysinibacillus sphaericus. Scanning electron micrographs of brood balls constructed from sterile dung reveals secretions and microbes only in the chamber the female prepares for the egg. The use of autoclaved dung for rearing, the presence of microbes in the brood ball and offspring, and identical 16S rRNA sequences in both parent and offspring suggests that the O. taurus female parent transmits specific microbiome members to her offspring through the brood

Lower Virus Infections in Varroa destructor-Infested and Uninfested Brood and Adult Honey Bees (Apis mellifera) of a Low Mite Population Growth Colony Compared to a High Mite Population Growth Colony

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Emsen, Berna; Hamiduzzaman, Mollah Md.; Goodwin, Paul H.; Guzman-Novoa, Ernesto

2015-01-01

A comparison was made of the prevalence and relative quantification of deformed wing virus (DWV), Israeli acute paralysis virus (IAPV), black queen cell virus (BQCV), Kashmir bee virus (KBV), acute bee paralysis virus (ABPV) and sac brood virus (SBV) in brood and adult honey bees (Apis mellifera) from colonies selected for high (HMP) and low (LMP) Varroa destructor mite population growth. Two viruses, ABPV and SBV, were never detected. For adults without mite infestation, DWV, IAPV, BQCV and KBV were detected in the HMP colony; however, only BQCV was detected in the LMP colony but at similar levels as in the HMP colony. With mite infestation, the four viruses were detected in adults of the HMP colony but all at higher amounts than in the LMP colony. For brood without mite infestation, DWV and IAPV were detected in the HMP colony, but no viruses were detected in the LMP colony. With mite infestation of brood, the four viruses were detected in the HMP colony, but only DWV and IAPV were detected and at lower amounts in the LMP colony. An epidemiological explanation for these results is that pre-experiment differences in virus presence and levels existed between the HMP and LMP colonies. It is also possible that low V. destructor population growth in the LMP colony resulted in the bees being less exposed to the mite and thus less likely to have virus infections. LMP and HMP bees may have also differed in susceptibility to virus infection. PMID:25723540

Experimental Shifts in Intraclutch Egg Color Variation Do Not Affect Egg Rejection in a Host of a Non-Egg-Mimetic Avian Brood Parasite

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Croston, Rebecca; Hauber, Mark E.

2015-01-01

Avian brood parasites lay their eggs in the nests of other birds, and impose the costs associated with rearing parasitic young onto these hosts. Many hosts of brood parasites defend against parasitism by removing foreign eggs from the nest. In systems where parasitic eggs mimic host eggs in coloration and patterning, extensive intraclutch variation in egg appearances may impair the host’s ability to recognize and reject parasitic eggs, but experimental investigation of this effect has produced conflicting results. The cognitive mechanism by which hosts recognize parasitic eggs may vary across brood parasite hosts, and this may explain variation in experimental outcome across studies investigating egg rejection in hosts of egg-mimicking brood parasites. In contrast, for hosts of non-egg-mimetic parasites, intraclutch egg color variation is not predicted to co-vary with foreign egg rejection, irrespective of cognitive mechanism. Here we tested for effects of intraclutch egg color variation in a host of nonmimetic brood parasite by manipulating egg color in American robins (Turdus migratorius), hosts of brown-headed cowbirds (Molothrus ater). We recorded robins’ behavioral responses to simulated cowbird parasitism in nests where color variation was artificially enhanced or reduced. We also quantified egg color variation within and between unmanipulated robin clutches as perceived by robins themselves using spectrophotometric measures and avian visual modeling. In unmanipulated nests, egg color varied more between than within robin clutches. As predicted, however, manipulation of color variation did not affect rejection rates. Overall, our results best support the scenario wherein egg rejection is the outcome of selective pressure by a nonmimetic brood parasite, because robins are efficient rejecters of foreign eggs, irrespective of the color variation within their own clutch. PMID:25831051

Experimental shifts in intraclutch egg color variation do not affect egg rejection in a host of a non-egg-mimetic avian brood parasite.

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Rebecca Croston

Full Text Available Avian brood parasites lay their eggs in the nests of other birds, and impose the costs associated with rearing parasitic young onto these hosts. Many hosts of brood parasites defend against parasitism by removing foreign eggs from the nest. In systems where parasitic eggs mimic host eggs in coloration and patterning, extensive intraclutch variation in egg appearances may impair the host's ability to recognize and reject parasitic eggs, but experimental investigation of this effect has produced conflicting results. The cognitive mechanism by which hosts recognize parasitic eggs may vary across brood parasite hosts, and this may explain variation in experimental outcome across studies investigating egg rejection in hosts of egg-mimicking brood parasites. In contrast, for hosts of non-egg-mimetic parasites, intraclutch egg color variation is not predicted to co-vary with foreign egg rejection, irrespective of cognitive mechanism. Here we tested for effects of intraclutch egg color variation in a host of nonmimetic brood parasite by manipulating egg color in American robins (Turdus migratorius, hosts of brown-headed cowbirds (Molothrus ater. We recorded robins' behavioral responses to simulated cowbird parasitism in nests where color variation was artificially enhanced or reduced. We also quantified egg color variation within and between unmanipulated robin clutches as perceived by robins themselves using spectrophotometric measures and avian visual modeling. In unmanipulated nests, egg color varied more between than within robin clutches. As predicted, however, manipulation of color variation did not affect rejection rates. Overall, our results best support the scenario wherein egg rejection is the outcome of selective pressure by a nonmimetic brood parasite, because robins are efficient rejecters of foreign eggs, irrespective of the color variation within their own clutch.

[Book review] Cowbirds and Other Brood Parasites by Catherine Ortega. Tucson, Arizona: University of Arizona Press (1998). The Avian Brood Parasites: Deception at the Nest by Paul A. Johnsgard. New York: Oxford University Press (1997) Parasitic Birds and their Hosts: Studies in Coevolution edited by S.I. Rothstein & S.K. Robinson. New York: Oxford University Press (1998)

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Hahn, D.C.

1999-01-01

We are in a golden age for the study of brood parasitism, judging from both the quantity and quality of recent scientific publications on cuckoos, cowbirds and parasitic finches by investigators working in Europe, the Americas, Africa and Asia. As Johnsgard (1997) remarks in his preface, the evolutionary, ecological, and behavioural questions posed by obligate brood parasites are among the most intriguing contemporary ornithological topics. Rothstein & Robinson (1998) explain that brood parasites make ideal subjects for testing the generality of models for the evolution of social and mating behaviour, foraging behaviour, spatial distribution, and vocal development, because the strategy of providing no parental care removes constraints imposed on other birds. Since Aristotle, people have been fascinated by brood parasites, but only in the past two decades has the number of investigators working on this topic reached a critical mass and created momentum that promises many breakthroughs. New studies are being completed so rapidly that a general book is inevitably out of date on some topics by the time it is published. A complete library on brood parasitism should add two recent volumes (Morrison et al. 1999; Smith et al., in press).to the three reviewed here.

Brood parasitism and quasi-parasitism in the European barn swallow Hirundo rustica rustica

Czech Academy of Sciences Publication Activity Database

Petrželková, Adéla; Michálková, R.; Albrechtová, Jana; Cepák, J.; Honza, Marcel; Kreisinger, J.; Munclinger, P.; Soudková, M.; Tomášek, Oldřich; Albrecht, Tomáš

2015-01-01

Roč. 69, č. 9 (2015), s. 1405-1414 ISSN 0340-5443 R&D Projects: GA ČR(CZ) GAP506/12/2472 Institutional support: RVO:68081766 Keywords : Altricial birds * Colonial breeding * Conspecific brood parasitism * Egg dumping * Host fitness * Parasite fitness Subject RIV: EG - Zoology Impact factor: 2.382, year: 2015

Effects of food availability on yolk androgen deposition in the black-legged kittiwake (Rissa tridactyla, a seabird with facultative brood reduction.

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Z M Benowitz-Fredericks

Full Text Available In birds with facultative brood reduction, survival of the junior chick is thought to be regulated primarily by food availability. In black-legged kittiwakes (Rissa tridactyla where parents and chicks are provided with unlimited access to supplemental food during the breeding season, brood reduction still occurs and varies interannually. Survival of the junior chick is therefore affected by factors in addition to the amount of food directly available to them. Maternally deposited yolk androgens affect competitive dynamics within a brood, and may be one of the mechanisms by which mothers mediate brood reduction in response to a suite of environmental and physiological cues. The goal of this study was to determine whether food supplementation during the pre-lay period affected patterns of yolk androgen deposition in free-living kittiwakes in two years (2003 and 2004 that varied in natural food availability. Chick survival was measured concurrently in other nests where eggs were not collected. In both years, supplemental feeding increased female investment in eggs by increasing egg mass. First-laid ("A" eggs were heavier but contained less testosterone and androstenedione than second-laid ("B" eggs across years and treatments. Yolk testosterone was higher in 2003 (the year with higher B chick survival across treatments. The difference in yolk testosterone levels between eggs within a clutch varied among years and treatments such that it was relatively small when B chick experienced the lowest and the highest survival probabilities, and increased with intermediate B chick survival probabilities. The magnitude of testosterone asymmetry in a clutch may allow females to optimize fitness by either predisposing a brood for reduction or facilitating survival of younger chicks.

Brood division in birds in relation to offspring size: sibling rivalry and parental control

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Slagsvold

1997-12-01

In some altricial birds with biparental care, it is the female, and in others the male, that provides more food to the smallest offspring within the brood. Many hypotheses have been proposed to account for such puzzling patterns of parental care. A parsimonious explanation is that no difference exists between the parents in priority of care but that differences arise simply from sibling rivalry, with dominant chicks trying to position themselves closest to the parent that provides most care (the sibling rivalry hypothesis). A refinement of the idea is that parents use the way they approach the chicks to counter selfish offspring and in this way control allocation of care (the parental approaching hypothesis). A comparison across species suggested that female care of the smallest chick within a brood is the ancestral and most common pattern. However, strong variation exists within single populations. In one species, the American robin, Turdus migratorius the sibling rivalry hypothesis and the parental approaching hypothesis were both supported because in broods where males provided more care than females, the largest chick was predominantly fed by the male whereas the smallest chick was predominantly fed by the female. When the male provided less care than the female, an opposite result was found. The same patterns of allocation of care also seemed to exist when chicks were quite immobile just after having left the nest and when their positions were experimentally controlled, suggesting parental control.Copyright 1997 The Association for the Study of Animal BehaviourCopyright 1997The Association for the Study of Animal Behaviour.

Repeatability of measurements of removal of mite-infested brood to assess Varroa Sensitive Hygiene

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Varroa Sensitive Hygiene is a useful resistance trait that bee breeders could increase in different populations with cost-effective and reliable tests. We investigated the reliability of a one-week test estimating the changes in infestation of brood introduced into highly selected and unselected co...

Alternative splicing of a single transcription factor drives selfish reproductive behavior in honeybee workers (Apis mellifera).

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Jarosch, Antje; Stolle, Eckart; Crewe, Robin M; Moritz, Robin F A

2011-09-13

In eusocial insects the production of daughters is generally restricted to mated queens, and unmated workers are functionally sterile. The evolution of this worker sterility has been plausibly explained by kin selection theory [Hamilton W (1964) J Theor Biol 7:1-52], and many traits have evolved to prevent conflict over reproduction among the females in an insect colony. In honeybees (Apis mellifera), worker reproduction is regulated by the queen, brood pheromones, and worker policing. However, workers of the Cape honeybee, Apis mellifera capensis, can evade this control and establish themselves as social parasites by activating their ovaries, parthenogenetically producing diploid female offspring (thelytoky) and producing queen-like amounts of queen pheromones. All these traits have been shown to be strongly influenced by a single locus on chromosome 13 [Lattorff HMG, et al. (2007) Biol Lett 3:292-295]. We screened this region for candidate genes and found that alternative splicing of a gene homologous to the gemini transcription factor of Drosophila controls worker sterility. Knocking out the critical exon in a series of RNAi experiments resulted in rapid worker ovary activation-one of the traits characteristic of the social parasites. This genetic switch may be controlled by a short intronic splice enhancer motif of nine nucleotides attached to the alternative splice site. The lack of this motif in parasitic Cape honeybee clones suggests that the removal of nine nucleotides from the altruistic worker genome may be sufficient to turn a honeybee from an altruistic worker into a parasite.

Gamma delta T cell responses associated with the development of tuberculosis in health care workers.

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Ordway, Diane J; Pinto, Luisa; Costa, Leonor; Martins, Marta; Leandro, Clara; Viveiros, Miguel; Amaral, Leonard; Arroz, Maria J; Ventura, Fernando A; Dockrell, Hazel M

2005-03-01

This study evaluated T cell immune responses to purified protein derivative (PPD) and Mycobacterium tuberculosis (Mtb) in health care workers who remained free of active tuberculosis (HCWs w/o TB), health care workers who went on to develop active TB (HCWs w/TB), non-health care workers who were TB free (Non-HCWs) and tuberculosis patients presenting with minimal (Min TB) or advanced (Adv TB) disease. Peripheral blood mononuclear cells (PBMC) were stimulated with Mtb and PPD and the expression of T cell activation markers CD25+ and HLA-DR+, intracellular IL-4 and IFN-gamma production and cytotoxic responses were evaluated. PBMC from HCWs who developed TB showed decreased percentages of cells expressing CD8+CD25+ in comparison to HCWs who remained healthy. HCWs who developed TB showed increased gammadelta TCR+ cell cytotoxicity and decreased CD3+gammadelta TCR- cell cytotoxicity in comparison to HCWs who remained healthy. PBMC from TB patients with advanced disease showed decreased percentages of CD25+CD4+ and CD25+CD8+ T cells that were associated with increased IL-4 production in CD8+ and gammadelta TCR+ phenotypes, in comparison with TB patients presenting minimal disease. TB patients with advanced disease showed increased gammadelta TCR+ cytotoxicity and reduced CD3+gammadelta TCR- cell cytotoxicity. Our results suggest that HCWs who developed TB show an early compensatory mechanism involving an increase in lytic responses of gammadelta TCR+ cells which did not prevent TB.

Social chromosome variants differentially affect queen determination and the survival of workers in the fire ant Solenopsis invicta.

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Buechel, Séverine D; Wurm, Yanick; Keller, Laurent

2014-10-01

Intraspecific variation in social organization is common, yet the underlying causes are rarely known. An exception is the fire ant Solenopsis invicta in which the existence of two distinct forms of social colony organization is under the control of the two variants of a pair of social chromosomes, SB and Sb. Colonies containing exclusively SB/SB workers accept only one single queen and she must be SB/SB. By contrast, when colonies contain more than 10% of SB/Sb workers, they accept several queens but only SB/Sb queens. The variants of the social chromosome are associated with several additional important phenotypic differences, including the size, fecundity and dispersal strategies of queens, aggressiveness of workers, and sperm count in males. However, little is known about whether social chromosome variants affect fitness in other life stages. Here, we perform experiments to determine whether differential selection occurs during development and in adult workers. We find evidence that the Sb variant of the social chromosome increases the likelihood of female brood to develop into queens and that adult SB/Sb workers, the workers that cull SB/SB queens, are overrepresented in comparison to SB/SB workers. This demonstrates that supergenes such as the social chromosome can have complex effects on phenotypes at various stages of development. © 2014 John Wiley & Sons Ltd.

Workers make the queens in melipona bees: identification of geraniol as a caste determining compound from labial glands of nurse bees.

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Jarau, Stefan; van Veen, Johan W; Twele, Robert; Reichle, Christian; Gonzales, Eduardo Herrera; Aguilar, Ingrid; Francke, Wittko; Ayasse, Manfred

2010-06-01

Reproductive division of labor in advanced eusocial honey bees and stingless bees is based on the ability of totipotent female larvae to develop into either workers or queens. In nearly all species, caste is determined by larval nutrition. However, the mechanism that triggers queen development in Melipona bees is still unresolved. Several hypotheses have been proposed, ranging from the proximate (a genetic determination of caste development) to the ultimate (a model in which larvae have complete control over their own caste fate). Here, we showed that the addition of geraniol, the main compound in labial gland secretions of nurse workers, to the larval food significantly increases the number of larvae that develop into queens. Interestingly, the proportion of queens in treated brood exactly matched the value (25%) predicted by the two-locus, two-allele model of genetic queen determination, in which only females that are heterozygous at both loci are capable of developing into queens. We conclude that labial gland secretions, added to the food of some cells by nurse bees, trigger queen development, provided that the larvae are genetically predisposed towards this developmental pathway. In Melipona beecheii, geraniol acts as a primer pheromone representing the first caste determination substance identified to date.

Paternity-parasitism trade-offs: a model and test of host-parasite cooperation in an avian conspecific brood parasite.

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Lyon, Bruce E; Hochachka, Wesley M; Eadie, John M

2002-06-01

Efforts to evaluate the evolutionary and ecological dynamics of conspecific brood parasitism in birds and other animals have focused on the fitness costs of parasitism to hosts and fitness benefits to parasites. However, it has been speculated recently that, in species with biparental care, host males might cooperate with parasitic females by allowing access to the host nest in exchange for copulations. We develop a cost-benefit model to explore the conditions under which such host-parasite cooperation might occur. When the brood parasite does not have a nest of her own, the only benefit to the host male is siring some of the parasitic eggs (quasi-parasitism). Cooperation with the parasite is favored when the ratio of host male paternity of his own eggs relative to his paternity of parasitic eggs exceeds the cost of parasitism. When the brood parasite has a nest of her own, a host male can gain additional, potentially more important benefits by siring the high-value, low-cost eggs laid by the parasite in her own nest. Under these conditions, host males should be even more likely to accept parasitic eggs in return for copulations with the parasitic female. We tested these predictions for American coots (Fulica americana), a species with a high frequency of conspecific brood parasitism. Multilocus DNA profiling indicated that host males did not sire any of the parasitic eggs laid in host nests, nor did they sire eggs laid by the parasite in her own nest. We used field estimates of the model parameters from a four-year study of coots to predict the minimum levels of paternity required for the costs of parasitism to be offset by the benefits of mating with brood parasites. Observed levels of paternity were significantly lower than those predicted under a variety of assumptions, and we reject the hypothesis that host males cooperated with parasitic females. Our model clarifies the specific costs and benefits that influence host-parasite cooperation and, more generally

A critical number of workers in a honeybee colony triggers investment in reproduction.

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Smith, Michael L; Ostwald, Madeleine M; Loftus, J Carter; Seeley, Thomas D

2014-10-01

Social insect colonies, like individual organisms, must decide as they develop how to allocate optimally their resources among survival, growth, and reproduction. Only when colonies reach a certain state do they switch from investing purely in survival and growth to investing also in reproduction. But how do worker bees within a colony detect that their colony has reached the state where it is adaptive to begin investing in reproduction? Previous work has shown that larger honeybee colonies invest more in reproduction (i.e., the production of drones and queens), however, the term 'larger' encompasses multiple colony parameters including number of adult workers, size of the nest, amount of brood, and size of the honey stores. These colony parameters were independently increased in this study to test which one(s) would increase a colony's investment in reproduction via males. This was assayed by measuring the construction of drone comb, the special type of comb in which drones are reared. Only an increase in the number of workers stimulated construction of drone comb. Colonies with over 4,000 workers began building drone comb, independent of the other colony parameters. These results show that attaining a critical number of workers is the key parameter for honeybee colonies to start to shift resources towards reproduction. These findings are relevant to other social systems in which a group's members must adjust their behavior as a function of the group's size.

A critical number of workers in a honeybee colony triggers investment in reproduction

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Smith, Michael L.; Ostwald, Madeleine M.; Loftus, J. Carter; Seeley, Thomas D.

2014-10-01

Social insect colonies, like individual organisms, must decide as they develop how to allocate optimally their resources among survival, growth, and reproduction. Only when colonies reach a certain state do they switch from investing purely in survival and growth to investing also in reproduction. But how do worker bees within a colony detect that their colony has reached the state where it is adaptive to begin investing in reproduction? Previous work has shown that larger honeybee colonies invest more in reproduction (i.e., the production of drones and queens), however, the term `larger' encompasses multiple colony parameters including number of adult workers, size of the nest, amount of brood, and size of the honey stores. These colony parameters were independently increased in this study to test which one(s) would increase a colony's investment in reproduction via males. This was assayed by measuring the construction of drone comb, the special type of comb in which drones are reared. Only an increase in the number of workers stimulated construction of drone comb. Colonies with over 4,000 workers began building drone comb, independent of the other colony parameters. These results show that attaining a critical number of workers is the key parameter for honeybee colonies to start to shift resources towards reproduction. These findings are relevant to other social systems in which a group's members must adjust their behavior as a function of the group's size.

Effect of Population Density on Timing of Oviposition and Brood Size Reduction in the Burying Beetle Nicrophorus pustulatus Herschel (Coleoptera: Silphidae

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Claudia M. Rauter

2012-01-01

Full Text Available Burying beetles (Nicrophorus spp. bury small carcasses to feed their larvae. Carcasses are a limited, high-quality resource and contests over carcasses become more frequent with increasing population density. Successful beetles kill eggs and larvae present on carcass. In response, females should accelerate oviposition, while offspring development should increase to minimize mortality. Both value of a carcass and frequency of contests decrease as larvae develop. If overproduction of offspring is an insurance against high mortality, females should reduce brood size as carcass value declines. Testing our predictions, we reared female burying beetles, Nicrophorus pustulatus, at high and low densities and compared oviposition and brood reduction. High-density females delayed oviposition, suggesting that high population density imposes nutritional and/or physiological stress. Females responded to the physiological constraints and the potentially high mortality rates of eggs and newly hatched larvae by lengthening oviposition period and changing brood reduction rate.

Eggshell strength of an obligate brood parasite: a test of the puncture resistance hypothesis

Czech Academy of Sciences Publication Activity Database

Antonov, A.; Stokke, B. G.; Moksnes, A.; Kleven, O.; Honza, Marcel; Roskaft, E.

2006-01-01

Roč. 60, č. 1 (2006), s. 11-18 ISSN 0340-5443 Grant - others:Research Council of Norway(NO) 151641/432 Institutional research plan: CEZ:AV0Z60930519 Keywords : brood parasitism * eggshell thickness * puncture resistance * Acrocephalus * cuckoo Subject RIV: EG - Zoology Impact factor: 2.316, year: 2006

Brood parasite and host eggshells undergo similar levels of decalcification during embryonic development

Czech Academy of Sciences Publication Activity Database

Igic, B.; Hauber, M. E.; Moskát, C.; Grim, T.; Shawkey, M. D.; Procházka, Petr; Honza, Marcel

2017-01-01

Roč. 301, č. 3 (2017), s. 165-173 ISSN 0952-8369 R&D Projects: GA ČR(CZ) GAP506/12/2404 Institutional support: RVO:68081766 Keywords : Acrocephalus arundinaceus * brood parasitism * Cuculus canorus * decalcification * eggshell thickness * embryonic development * common cuckoo * scanning electron microscopy Subject RIV: EG - Zoology OBOR OECD: Zoology Impact factor: 2.186, year: 2016

Do brooding and polygamy behaviors exist on Cretaceous oviraptoroid dinosaurs of China: a paleobiological perspective

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Yang, T.-R.; Cheng, Y.-N.; Yang, K.-M.

2012-04-01

Brooding, parental care, and polygamy represent three different stages in bird's reproduction. The oringin of these behaviors is still in debate. Several samples excavated from China strengthen the phylogenetic relationship between birds and dinosaurs, for example, feathered dinosaurs, paired-eggs in pelvic region of an oviraptorid dinosaur, and small theropod fossils. Previous studies in past two decades, including an oviraptor sitting on a clutch and comparison of the ratio of clutch-volume to adult-body-size between Aves and Mesozoic dinosaurs, proposed that these behaviors had appeared on some Cretaceous theropods (e.g., oviraptor and troodon). These researches also indicate the possibility of endothermy and male care first. In conclusion, this reproduction strategy might support females having more remnant energy to build a larger clutch contributed eggs from multiple females, and brooded by males only. From our cluster analysis through paleoecological perspectives, the eggs in Cretaceous oviraptor's nest should not be corporately laid by multiple females. In morphological observation, the fossilized clutches from Ganzhou, Jiangxi, Mainland China, are 2-layered interbeded with matrix of reddish-brown siltstone or clays. The inner-layer eggs are hampered from directly contacting with adult dinosaurs body. Furthermore, the blunt ends of the eggs point to the center, and incline away forming a mound-shape nest, which is completely different from those of precocial and male-caring megapode. The ornamentation of eggshell surface and microstructures from thin sections of eggs from oviraptors and ostrich (Struthioniformes) are totally different. Comparison of thickness in different part of oviraptor's egg also reveal possible physiological structure in the egg and ecological behaviors. The detailed comparison implies that the Mesozoic oviraptoroid dinosaurs hold absolutely different incubation and caring behaviors from extant birds. We propose an alternative

Molecular evidence for extra-pair paternity and intraspecific brood parasitism in the Black-headed Gull

Czech Academy of Sciences Publication Activity Database

Ležalová-Piálková, Radka

2011-01-01

Roč. 152, č. 2 (2011), s. 291-295 ISSN 0021-8375 Institutional research plan: CEZ:AV0Z60930519 Keywords : Black-headed Gull * genetic mating system * extra-pair paternity * intraspecific brood parasitism Subject RIV: EG - Zoology Impact factor: 1.636, year: 2011

Effects of hatching asynchrony on sibling negotiation, begging, jostling for position and within-brood food allocation in the barn owl Tyto alba

OpenAIRE

Roulin, A.

2004-01-01

When siblings differ markedly in their need for food, they may benefit from signalling to each other their willingness to contest the next indivisible food item delivered by the parents. This sib-sib communication system, referred to as 'sibling negotiation', may allow them to adjust optimally to investment in begging. Using barn owl (Two alba) broods. I assessed the role of within-brood age hierarchy on sibling negotiation, and in turn on jostling for position where parents predictably deliv...

The Antarctic holothurian genus Echinopsolus Gutt, 1990 (Dendrochirotida, Cucumariidae): brood pouches, spermatozoa, spermatozeugmata and taxonomic implications.

Science.gov (United States)

Bohn, Jens Michael; Heß, Martin

2014-07-29

An examination of seven Antarctic brooding cucumariid and psolid holothurian species revealed a variety of characters all of them have in common: (1) All are gonochoric. (2) A genital papilla is present on the oral disc (permanent and digitiform in males). (3) Females brood their offspring in five anterior interradial brood pouches that are situated at the transition of body to introvert. (4) Multiple spermatozoa are always bundled to bunch-like spermato-zeugmata. (5) The spermatozoa have a fusiform head and a hollow cylinder-like mid-piece encircling the anterior end of the flagellum. This combination of characters so far is unique, and indicates a close relationship based on common origin. As a consequence, we unite all species sharing this set of synapomorphies in the genus Echinopsolus Gutt, 1990. The herewith included species are: E. acanthocola Gutt, 1990, E. acutus (Massin, 1992) comb. nov., E. charcoti (Vaney, 1906) comb. nov., E. koehleri (Vaney, 1914) comb. nov., E. mollis (Ludwig & Heding, 1935) comb. nov., E. parvipes Massin, 1992 and E. splendidus (Gutt, 1990) comb. nov.. Because the current assignment of Echinopsolus to the family Psolidae can not be retained, the genus is tranferred to the family Cucumariidae, as relationships to taxa within this family are obvious. The peculiar spermatozoa and spermato-zeugmata of all Echinopsolus species are described using light- and electron-microscopical techniques and the results are evaluated and discussed concerning their taxonomy and phylogeny. 

Queens and Workers Contribute Differently to Adaptive Evolution in Bumble Bees and Honey Bees.

Science.gov (United States)

Harpur, Brock A; Dey, Alivia; Albert, Jennifer R; Patel, Sani; Hines, Heather M; Hasselmann, Martin; Packer, Laurence; Zayed, Amro

2017-09-01

Eusociality represents a major transition in evolution and is typified by cooperative brood care and reproductive division of labor between generations. In bees, this division of labor allows queens and workers to phenotypically specialize. Worker traits associated with helping are thought to be crucial to the fitness of a eusocial lineage, and recent studies of honey bees (genus Apis) have found that adaptively evolving genes often have worker-biased expression patterns. It is unclear however if worker-biased genes are disproportionately acted on by strong positive selection in all eusocial insects. We undertook a comparative population genomics study of bumble bees (Bombus) and honey bees to quantify natural selection on queen- and worker-biased genes across two levels of social complexity. Despite sharing a common eusocial ancestor, genes, and gene groups with the highest levels of positive selection were often unique within each genus, indicating that life history and the environment, but not sociality per se, drives patterns of adaptive molecular evolution. We uncovered differences in the contribution of queen- and worker-biased genes to adaptive evolution in bumble bees versus honey bees. Unlike honey bees, where worker-biased genes are enriched for signs of adaptive evolution, genes experiencing positive selection in bumble bees were predominately expressed by reproductive foundresses during the initial solitary-founding stage of colonies. Our study suggests that solitary founding is a major selective pressure and that the loss of queen totipotency may cause a change in the architecture of selective pressures upon the social insect genome. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Use of geostatistics on broiler production for evaluation of different minimum ventilation systems during brooding phase

Directory of Open Access Journals (Sweden)

Thayla Morandi Ridolfi de Carvalho

2012-01-01

Full Text Available The objective of this research was to evaluate different minimum ventilation systems, in relation to air quality and thermal comfort using geostatistics in brooding phase. The minimum ventilation systems were: Blue House I: exhaust fans + curtain management (end of the building; Blue House II: exhaust fans + side curtain management; and Dark House: exhaust fans + flag. The climate variables evaluated were: dry bulb temperature, relative humidity, air velocity, carbon dioxide and ammonia concentration, during winter time, at 9 a.m., in 80 equidistant points in brooding area. Data were evaluated by geostatistic technique. The results indicate that Wider broiler houses (above 15.0 m width present the greatest ammonia and humidity concentration. Blue House II present the best results in relation to air quality. However, none of the studied broiler houses present an ideal thermal comfort.

Distribution and female reproductive state differences in orexigenic and anorexigenic neurons in the brain of the mouth brooding African cichlid fish, Astatotilapia burtoni.

Science.gov (United States)

Porter, Danielle T; Roberts, David A; Maruska, Karen P

2017-10-01

Integration of reproduction and metabolism is necessary for species survival. While the neural circuits controlling energy homeostasis are well-characterized, the signals controlling the relay of nutritional information to the reproductive axis are less understood. The cichlid fish Astatotilapia burtoni is ideal for studying the neural regulation of feeding and reproduction because females cycle between a feeding gravid state and a period of forced starvation while they brood developing young inside their mouths. To test the hypothesis that candidate neuropeptide-containing neurons known to be involved in feeding and energy homeostasis in mammals show conserved distribution patterns, we performed immunohistochemistry and in situ hybridization to localize appetite-stimulating (neuropeptide Y, NPY; agouti-related protein, AGRP) and appetite-inhibiting (cocaine and amphetamine-regulated transcript, CART; pro-opiomelanocortin, pomc1a) neurons in the brain. NPY, AGRP, CART, and pomc1a somata showed distribution patterns similar to other teleosts, which included localization to the lateral tuberal nucleus (NLT), the putative homolog of the mammalian arcuate nucleus. Gravid females also had larger NPY and AGRP neurons in the NLT compared to brooding females, but brooding females had larger pomc1a neurons compared to gravid females. Hypothalamic agrp mRNA levels were also higher in gravid compared to brooding females. Thus, larger appetite-stimulating neurons (NPY, AGRP) likely promote feeding while females are gravid, while larger pomc1a neurons may act as a signal to inhibit food intake during mouth brooding. Collectively, our data suggest a potential role for NPY, AGRP, POMC, and CART in regulating energetic status in A. burtoni females during varying metabolic and reproductive demands. © 2017 Wiley Periodicals, Inc.

Founding weaver ant queens (Oecophylla longinoda) increase production and nanitic worker size when adopting non-nestmate pupae

DEFF Research Database (Denmark)

Ouagoussounon, Issa; Offenberg, Joachim; Sinzogan, Antonio

2015-01-01

Weaver ants (Oecophylla longinoda Latreille) are used commercially to control pest insects and for protein production. In this respect fast colony growth is desirable for managed colonies. Transplantation of non-nestmate pupae to incipient colonies has been shown to boost colony growth. Our...... of 300 pupae increased total colony size more than 10-fold whereas 100 pupae increased the size 5.6 fold, compared to control. This increase was due not only to the individuals added in the form of pupae but also to an increased per capita brood production by the resident queen, triggered by the adopted...... objectives were to find the maximum number of pupae a founding queen can handle, and to measure the associated colony growth. Secondly, we tested if transplantation of pupae led to production of larger nanitic workers (defined as unusually small worker ants produced by founding queens in their first batch...

Mitosis and cell death in the optic lobes of workers, queens and ...

Indian Academy of Sciences (India)

Prakash

of white, pink, brown and black eyes, and the beginning of tegument ... Our purpose was to investigate cell division and death in the optic lobes (OL) of workers, queens and males during ... new ones in each caste and sex. Nevertheless, most ...

Odorant cues linked to social immunity induce lateralized antenna stimulation in honey bees (Apis mellifera L.).

Science.gov (United States)

McAfee, Alison; Collins, Troy F; Madilao, Lufiani L; Foster, Leonard J

2017-04-07

Hygienic behaviour (HB) is a social immunity trait in honey bees (Apis mellifera L.) whereby workers detect, uncap and remove unhealthy brood, improving disease resistance in the colony. This is clearly economically valuable; however, the molecular mechanism behind it is not well understood. The freeze-killed brood (FKB) assay is the conventional method of HB selection, so we compared odour profiles of FKB and live brood to find candidate HB-inducing odours. Surprisingly, we found that significantly more brood pheromone (β-ocimene) was released from FKB. β-ocimene abundance also positively correlated with HB, suggesting there could be a brood effect contributing to overall hygiene. Furthermore, we found that β-ocimene stimulated worker antennae in a dose-dependent manner, with the left antennae responding significantly stronger than right antennae in hygienic bees, but not in non-hygienic bees. Five other unidentifiable compounds were differentially emitted from FKB which could also be important for HB. We also compared odour profiles of Varroa-infested brood to healthy brood and found an overall interactive effect between developmental stage and infestation, but specific odours did not drive these differences. Overall, the data we present here is an important foundation on which to build our understanding the molecular mechanism behind this complex behaviour.

Demography and life history characteristics of two honey bee races (Apis mellifera).

Science.gov (United States)

Winston, Mark L; Dropkin, Jennifer A; Taylor, Orley R

1981-03-01

Intra-colony demography and life history characteristics of neotropical Africanized and temperate European honey bearaces were compared under simulated feral conditions. Major differences in colony demography were found which nevertheless resulted in some similar reproductive characteristics. European colonies were larger than Africanized colonies, had more rapid initral growth rates of worker populations, showed better survivorship of brood and adult workers, and differed in patterns of worker age distribution. However, both races were similar in the brood and adult populations when colonies swarmed, the frequency and timing of swarming, and the number of workers in prime swarms. The factors most important in determining these colony growth and reproductive patterns were likely worker mortality rates, climate, and resource availability.

Brood parasitic cowbird nestlings use host young to procure resources.

Science.gov (United States)

Kilner, Rebecca M; Madden, Joah R; Hauber, Mark E

2004-08-06

Young brood parasites that tolerate the company of host offspring challenge the existing evolutionary view of family life. In theory, all parasitic nestlings should be ruthlessly self-interested and should kill host offspring soon after hatching. Yet many species allow host young to live, even though they are rivals for host resources. Here we show that the tolerance of host nestlings by the parasitic brown-headed cowbird Molothrus ater is adaptive. Host young procure the cowbird a higher provisioning rate, so it grows more rapidly. The cowbird's unexpected altruism toward host offspring simply promotes its selfish interests in exploiting host parents.

Translocation of threatened New Zealand falcons to vineyards increases nest attendance, brooding and feeding rates.

Directory of Open Access Journals (Sweden)

Sara M Kross

Full Text Available Anthropogenic landscapes can be rich in resources, and may in some cases provide potential habitat for species whose natural habitat has declined. We used remote videography to assess whether reintroducing individuals of the threatened New Zealand falcon Falco novaeseelandiae into a highly modified agricultural habitat affected the feeding rates of breeding falcons or related breeding behavior such as nest attendance and brooding rates. Over 2,800 recording hours of footage were used to compare the behavior of falcons living in six natural nests (in unmanaged, hilly terrain between 4 km and 20 km from the nearest vineyard, with that of four breeding falcon pairs that had been transported into vineyards and nested within 500 m of the nearest vineyard. Falcons in vineyard nests had higher feeding rates, higher nest attendance, and higher brooding rates. As chick age increased, parents in vineyard nests fed chicks a greater amount of total prey and larger prey items on average than did parents in hill nests. Parents with larger broods brought in larger prey items and a greater total sum of prey biomass. Nevertheless, chicks in nests containing siblings received less daily biomass per individual than single chicks. Some of these results can be attributed to the supplementary feeding of falcons in vineyards. However, even after removing supplementary food from our analysis, falcons in vineyards still fed larger prey items to chicks than did parents in hill nests, suggesting that the anthropogenic habitat may be a viable source of quality food. Although agricultural regions globally are rarely associated with raptor conservation, these results suggest that translocating New Zealand falcons into vineyards has potential for the conservation of this species.

The role of egg-nest contrast in the rejection of brood parasitic eggs.

Science.gov (United States)

Aidala, Zachary; Croston, Rebecca; Schwartz, Jessica; Tong, Lainga; Hauber, Mark E

2015-04-15

Hosts of avian brood parasites can avoid the reproductive costs of raising genetically unrelated offspring by rejecting parasitic eggs. The perceptual cues and controls mediating parasitic egg discrimination and ejection are well studied: hosts are thought to use differences in egg color, brightness, maculation, size and shape to discriminate between their own and foreign eggs. Most theories of brood parasitism implicitly assume that the primary criteria to which hosts attend when discriminating eggs are differences between the eggs themselves. However, this assumption is confounded by the degree to which chromatic and achromatic characteristics of the nest lining co-vary with egg coloration, so that egg-nest contrast per se might be the recognition cue driving parasitic egg detection. Here, we systematically tested whether and how egg-nest contrast itself contributes to foreign egg discrimination. In an artificial parasitism experiment, we independently manipulated egg color and nest lining color of the egg-ejector American robin (Turdus migratorius), a host of the obligate brood parasitic brown-headed cowbird (Molothrus ater). We hypothesized that the degree of contrast between foreign eggs and the nest background would affect host egg rejection behavior. We predicted that experimentally decreasing egg-nest chromatic and achromatic contrast (i.e. rendering parasitic eggs more cryptic against the nest lining) would decrease rejection rates, while increasing egg-nest contrast would increase rejection rates. In contrast to our predictions, egg-nest contrast was not a significant predictor of egg ejection patterns. Instead, egg color significantly predicted responses to parasitism. We conclude that egg-egg differences are the primary drivers of egg rejection in this system. Future studies should test for the effects of egg-nest contrast per se in predicting parasitic egg recognition in other host-parasite systems, including those hosts building enclosed nests and

Somatic cell genetics of uranium miners and plutonium workers. A biological dose-response indicator

International Nuclear Information System (INIS)

Brandom, W.F.; Bloom, A.D.; Bistline, R.W.; Saccomanno, G.

1978-01-01

Two populations of underground uranium miners and plutonium workers work in the state of Colorado, United States of America. We have explored the prevalence of structural chromosome aberrations in peripheral blood lymphocytes as a possible biological indicator of absorbed radiation late-effects in these populations. The uranium miners are divided into four exposure groups expressed in Working Level Months (WLM), the plutonium workers into six groups with estimated 239 Pu burdens expressed in nCi. Comparison of chromosome aberration frequency data between controls, miners, and plutonium workers demonstrate: (1) a cytogenetic response to occupational ionizing radiation at low estimated doses; and (2) an increasing monotonic dose-response in the prevalence of complex (all exchange) or total aberrations in all exposure groups in these populations. We also compared trends in the prevalence of aberrations per exposure unit (WLM and nCi) in each exposure subgroup for each population. In the uranium miners, the effects per WLM seem to decrease monotonically with increasing dose, whereas in the Pu workers the change per nCi appears abrupt, with all exposure groups over 1.3 nCi (minimum detectable level) having essentially similar rates. The calculations of aberrations per respective current maximum permissible dose (120 WLM and 40 nCi) for the two populations yield 4.8 X 10 -2 /100 cells for uranium miners and 90.6 X 10 -2 /100 cells for Pu workers. Factors which may have influenced this apparent 20-fold increase in the effectiveness of plutonium in the production of complex aberrations (9-fold increase in total aberrations) are discussed. (author)

Brood size and sex ratio in response to host quality and wasp traits in the gregarious parasitoid Oomyzus sokolowskii (Hymenoptera: Eulophidae

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Xianwei Li

2017-01-01

Full Text Available This laboratory study investigated whether the larval-pupal parasitoid Oomyzus sokolowskii females adjust their brood size and sex ratio in response to body size and stage of Plutella xylostella larval hosts, as well as to their own body size and the order of oviposition. These factors were analyzed using multiple regression with simultaneous entry of them and their two-way interactions. Parasitoids brood size tended to increase with host body size at parasitism when the 4th instar larval host was attacked, but did not change when the 2nd and 3rd instar larvae were attacked. Parasitoids did not vary in brood size according to their body size, but decreased with their bouts of oviposition on a linear trend from 10 offspring adults emerged per host in the first bout of oviposition down to eight in the third. Parasitoid offspring sex ratio did not change with host instar, host body weight, wasp body size, and oviposition bout. Proportions of male offspring per brood were from 11% to 13% from attacking the 2nd to 4th instar larvae and from 13% to 16% across three successive bouts of oviposition, with a large variation for smaller host larvae and wasps. When fewer than 12 offspring were emerged from a host, one male was most frequently produced; when more than 12 offspring were emerged, two or more males were produced. Our study suggests that O. sokolowskii females may optimize their clutch size in response to body size of mature P. xylostella larvae, and their sex allocation in response to clutch size.

Food poisoning associated with ingestion of wild wasp broods in the upstream region of the Lancang river valley, Yunnan province, China.

Science.gov (United States)

Jiang, Li; Huang, Tian

2018-04-01

Food poisoning due to wild wasp broods ingestion has long been noted in the upstream region of the Lancang river valley, Yunnan province, China. This study describes the epidemiological and clinical features of the poisoning and possible causes. Surveillance data collected between 2008 and 2016 were analyzed to produce demographic data on patients, information on clinical presentations, wasp species identification, and estimations of possible risk factors for symptomatic cases. Eleven poisoning events were associated with the ingestion of wild wasp broods, including 46 exposed persons with 31 symptomatic living cases and 8 deceased cases that were reported in the Yunnan province between 2008 and 2016. Poisoning cases were only detected in the upstream region of the Lancang river valley in the autumn. The severity of the symptoms was correlated with an evident dose-effect relationship regarding the quantity ingested. The mean latent period from wild wasp broods ingestion to the onset of the symptoms was 10 h for symptomatic living cases and 7 h for deceased cases, respectively. Both gastrointestinal and neurological symptoms were commonly observed in the poisoning cases. The toxin source may be indirectly caused by the wasp broods due to the prevalence of local poisonous plants, such as Tripterygium wilfordii Hook F, Tripterygium hypoglaucum Hutch and Vaccinium bracteatum Thunb. Educational programs at the start of wasp harvest season in September in the high-risk area should be carried out to reduce the incidence of poisonings. Copyright © 2018 Elsevier Ltd. All rights reserved.

Breeding success of a brood parasite is associated with social mating status of its host

Czech Academy of Sciences Publication Activity Database

Trnka, A.; Požgayová, Milica; Procházka, Petr; Prokop, P.; Honza, Marcel

2012-01-01

Roč. 66, č. 8 (2012), s. 1187-1194 ISSN 0340-5443 R&D Projects: GA AV ČR IAA600930903; GA ČR(CZ) GAP506/12/2404 Institutional support: RVO:68081766 Keywords : brood parasitism * cuckoo * great reed warbler * polygyny * reproductive success Subject RIV: EG - Zoology Impact factor: 2.752, year: 2012

Consistency in egg rejection behaviour: responses to repeated brood parasitism in the blackcap (Sylvia atricapilla)

Czech Academy of Sciences Publication Activity Database

Honza, Marcel; Požgayová, Milica; Procházka, Petr; Tkadlec, Emil

2007-01-01

Roč. 113, č. 4 (2007), s. 344-351 ISSN 0179-1613 R&D Projects: GA AV ČR IAA600930605; GA ČR(CZ) GD524/05/H536 Institutional research plan: CEZ:AV0Z60930519 Keywords : brood parasitism * cuckoo * blackcap Subject RIV: EG - Zoology Impact factor: 1.902, year: 2007

Parental genetic diversity of brown trout (Salmo trutta m. fario) brood stock affects offspring susceptibility to whirling disease.

Science.gov (United States)

Eszterbauer, Edit; Forró, Barbara; Tolnai, Zoltán; Guti, Csaba Ferenc; Zsigmond, Gergely; Hoitsy, György; Kallert, Dennis Marc

2015-03-03

Whirling disease, caused by the myxozoan parasite Myxobolus cerebralis, has high economical and ecological importance worldwide. Susceptibility to the disease varies considerably among salmonid species. In brown trout (Salmo trutta) the infection is usually subclinical with low mortality, which increases the risk of parasite dissemination, especially when farm fish are used for stocking natural habitats. The influence of intraspecific genetic differences (especially the level of homozygosity) on susceptibility is unknown. Therefore, we examined the possible correlations between parental genetic diversity and offspring susceptibility of brown trout stocks to whirling disease. Two brown trout brood stocks from a German and a Hungarian fish farm were genetically characterized using microsatellite and lineage-specific genetic markers. The individual inbreeding coefficient f and pairwise relatedness factor r were estimated based on eight microsatellite markers. Brood stock populations were divided into groups according to low and high f and r value estimates and subjected to selective fertilization. The offspring from these separate groups were exposed to M. cerebralis actinospores, and the infection prevalence and intensity was measured and statistically analysed. The analysis of phylogeographic lineage heritage revealed high heterogeneity in the Hungarian brood stock since > 50% of individuals were Atlantic-Danubian hybrids, while only pure Atlantic-descending specimens were detected in the German population. Based on f msat and r msat estimations, classified non-inbred (NIB), inbred (IB) and a group of closely related fish (REL) were created. The susceptibility of their offspring varied considerably. Although there was no significant difference in the prevalence of M. cerebralis infection, the mean intensity of infection differed significantly between NIB and IB groups. In REL and IB groups, a high variability was observed in infection intensity. No external

The Effect of Temperature on Synchronization of Brood Development of the Bopyrid Isopod Parasite Probopyrus pandalicola with Molting of Its Host, the Daggerblade Grass Shrimp Palaemonetes pugio.

Science.gov (United States)

Brinton, Brigette A; Curran, Mary Carla

2015-08-01

The bopyrid isopod Probopyrus pandalicola is a hematophagous ectoparasite that sexually sterilizes some palaemonid shrimps, including female daggerblade grass shrimp Palaemonetes pugio. The reproduction of parasitic isopods is thought to occur synchronously with host molting because the brood would be unsuccessful if molting occurred before the larvae were free swimming. Temperature affects the length of the molting cycle of shrimp, and therefore may also affect the incubation time of isopod broods. The purpose of the present study was to determine the effect of temperature on brood development of the parasite and on the degree of synchronization with the molting of its host. Parasitized P. pugio were monitored daily at 2 experimental temperatures, 23 and 15 C, in temperature-controlled chambers for the duration of a full parasite reproductive cycle. Developmental stage was determined by the visible coloration of the brood through the exoskeleton of the host, and was designated as egg, embryo I, embryo II, or epicaridium larvae. Temperature significantly affected median brood incubation time, which was only 11 days at 23 C, as compared to 35 days at 15 C. The final developmental stage (epicaridium larvae) was 3 times shorter at 23 C (median 3 days; n = 45) than at 15 C (median 9 days; n = 15). Temperature significantly affected the intermolt period of parasitized shrimp, which was shorter at 23 C (median 12 days) than at 15 C (median 37 days). A smaller percentage of the intermolt period elapsed between larval release and shrimp molting at 23 C (0.0%) than at 15 C (3.1%), indicating closer synchronization between host molting and parasite reproduction at the warmer temperature. At 15 C, the isopods utilized a smaller proportion of the time that was available for brood incubation during the intermolt period of their host. Brood size ranged from 391 to 4,596 young and was positively correlated with parasite and host size. Because development progressed more rapidly

Strategic variation in mobbing as a front line of defense against brood parasitism.

Science.gov (United States)

Welbergen, Justin A; Davies, Nicholas B

2009-02-10

Coevolutionary arms races, where adaptations in one party select for counter-adaptations in another and vice versa, are fundamental to interactions between organisms and their predators, pathogens, and parasites [1]. Avian brood parasites and their hosts have emerged as model systems for studying such reciprocal coevolutionary processes [2, 3]. For example, hosts have evolved changes in egg appearance and rejection of foreign eggs in response to brood parasitism from cuckoos, and cuckoos have evolved host-egg mimicry as a counter-response [4-6]. However, the host's front line of defense is protecting the nest from being parasitized in the first place [7-10], yet little is known about the effectiveness of nest defense as an antiparasite adaptation, and its coevolutionary significance remains poorly understood [10]. Here we show first that mobbing of common cuckoos Cuculus canorus by reed warblers Acrocephalus scirpaceus is an effective defense against parasitism. Second, mobbing of cuckoos is a phenotypically plastic trait that is modified strategically according to local parasitism risk. This supports the view that hosts use a "defense in-depth strategy," with successive flexible lines of defense that coevolve with corresponding offensive lines of the parasite. This highlights the need for more holistic research into the coevolutionary consequences when multiple adaptations and counter-adaptations evolve in concert [11].

Chemical defence in avian brood parasites: production and function of repulsive secretions in common cuckoo chicks

Czech Academy of Sciences Publication Activity Database

Trnka, A.; Požgayová, Milica; Procházka, Petr; Čapek, Miroslav; Honza, Marcel

2016-01-01

Roč. 47, č. 2 (2016), s. 288-293 ISSN 0908-8857 R&D Projects: GA ČR(CZ) GAP506/12/2404 Institutional support: RVO:68081766 Keywords : brood parasitism * common cuckoo Cuculus canorus * malodorous secretion * nest predation * repellency Subject RIV: EG - Zoology Impact factor: 2.228, year: 2016

Pheromone-modulated behavioral suites influence colony growth in the honey bee (Apis mellifera)

Science.gov (United States)

Pankiw, Tanya; Roman, Roman; Sagili, Ramesh R.; Zhu-Salzman, Keyan

2004-12-01

The success of a species depends on its ability to assess its environment and to decide accordingly which behaviors are most appropriate. Many animal species, from bacteria to mammals, are able to communicate using interspecies chemicals called pheromones. In addition to exerting physiological effects on individuals, for social species, pheromones communicate group social structure. Communication of social structure is important to social insects for the allocation of its working members into coordinated suites of behaviors. We tested effects of long-term treatment with brood pheromone on suites of honey bee brood rearing and foraging behaviors. Pheromone-treated colonies reared significantly greater brood areas and more adults than controls, while amounts of stored pollen and honey remained statistically similar. Brood pheromone increased the number of pollen foragers and the pollen load weights they returned. It appeared that the pheromone-induced increase in pollen intake was directly canalized into more brood rearing. A two-way pheromone priming effect was observed, such that some workers from the same age cohorts showed an increased and extended capacity to rear larvae, while others were recruited at significantly younger ages into pollen-specific foraging. Brood pheromone affected suites of nursing and foraging behaviors allocating worker and pollen resources associated with an important fitness trait, colony growth.

Nutritional upgrading for omnivorous carpenter ants by the endosymbiont Blochmannia

Directory of Open Access Journals (Sweden)

Mueller Martin J

2007-10-01

Full Text Available Abstract Background Carpenter ants (genus Camponotus are considered to be omnivores. Nonetheless, the genome sequence of Blochmannia floridanus, the obligate intracellular endosymbiont of Camponotus floridanus, suggests a function in nutritional upgrading of host resources by the bacterium. Thus, the strongly reduced genome of the endosymbiont retains genes for all subunits of a functional urease, as well as those for biosynthetic pathways for all but one (arginine of the amino acids essential to the host. Results Nutritional upgrading by Blochmannia was tested in 90-day feeding experiments with brood-raising in worker-groups on chemically defined diets with and without essential amino acids and treated or not with antibiotics. Control groups were fed with cockroaches, honey water and Bhatkar agar. Worker-groups were provided with brood collected from the queenright mother-colonies (45 eggs and 45 first instar larvae each. Brood production did not differ significantly between groups of symbiotic workers on diets with and without essential amino acids. However, aposymbiotic worker groups raised significantly less brood on a diet lacking essential amino acids. Reduced brood production by aposymbiotic workers was compensated when those groups were provided with essential amino acids in their diet. Decrease of endosymbionts due to treatment with antibiotic was monitored by qRT-PCR and FISH after the 90-day experimental period. Urease function was confirmed by feeding experiments using 15N-labelled urea. GC-MS analysis of 15N-enrichment of free amino acids in workers revealed significant labelling of the non-essential amino acids alanine, glycine, aspartic acid, and glutamic acid, as well as of the essential amino acids methionine and phenylalanine. Conclusion Our results show that endosymbiotic Blochmannia nutritionally upgrade the diet of C. floridanus hosts to provide essential amino acids, and that it may also play a role in nitrogen recycling

Variation in foraging behavior and body mass in broods of Emperor Geese (Chen canagica): Evidence for interspecific density dependence

Science.gov (United States)

Schmutz, J.A.; Laing, K.K.

2002-01-01

Broods of geese spend time feeding according to availability and quality of food plants, subject to inherent foraging and digestive constraints. We studied behavioral patterns of broods of Emperor Geese (Chen canagica) on the Yukon–Kuskokwim Delta, Alaska, and examined how feeding and alert behavior varied in relation to habitat and goose density. During 1994–1996, time spent feeding by Emperor Goose goslings and adult females was positively related to multispecies goose densities near observation blinds, and not to just Emperor Goose density. Similarly, body mass of Emperor Goose goslings was more strongly related (negatively) to multispecies goose densities than intraspecific densities. A grazing experiment in 1995 indicated that most above ground primary production by Carex subspathacea, a preferred food plant, was consumed by grazing geese. Those results demonstrate that interspecific competition for food occurred, with greatest support for goslings whose behavioral repertoire is limited primarily to feeding, digesting, and resting. Although the more abundant Cackling Canada Geese (Branta canadensis minima) differed from Emperor Geese in their preferred use of habitats during brooding rearing (Schmutz 2001), the two species occurred in equal abundance in habitats preferred by Emperor Goose broods. Thus, Cackling Canada Geese were a numerically significant competitor with Emperor Geese. Comparing these results to an earlier study, time spent feeding by goslings, adult females, and adult males were greater during 1993–1996 than during 1985–1986. During the interval between those studies, densities of Cackling Canada Geese increased two to three times whereas Emperor Goose numbers remained approximately stable, which implies that interspecific competition affected foraging behavior over a long time period. These density-dependent changes in foraging behavior and body mass indicate that interspecific competition affects nutrient acquisition and gosling

Perceived Workforce Challenges among Clinical Social Workers in Hematopoietic Cell Transplantation Programs.

Science.gov (United States)

Stickney Ferguson, Stacy; Randall, Jill; Dabney, Jane; Kalbacker, Marion E; Boyle, Nancy; Thao, Viengneesee; Murphy, Elizabeth A; Denzen, Ellen M

2018-05-01

Clinical social workers are psychosocial care experts who provide interventions that aim to address the emotional, relational, financial, and logistical challenges that arise throughout the hematopoietic cell transplantation (HCT) treatment and recovery process. Interventions that contribute to better patient outcomes can include cognitive behavioral therapy and counseling for adaptation to illness, family planning for 24/7 caregiver availability and strategies to support patient activities of daily living, instruction on guided imagery and relaxation techniques for symptom management and to decrease anxiety, psychoeducation on the treatment trajectory, and linkage with financial resources. A Social Work Workforce Group (SWG) was established through the System Capacity Initiative, led by the National Marrow Donor Program/Be The Match, to characterize the current social work workforce capacity and challenges. The SWG conducted a web-based survey of HCT clinical social workers in the United States. The response rate was 57% (n = 90), representing 76 transplant centers. Survey results indicated that the clinical social worker role and scope of practice varies significantly between centers; less than half of respondents reported that their clinical social work expertise was used to its fullest potential. With an estimated 3-fold increase in HCT patient volume by 2020, the need for specialized psychosocial health services will increase. The SWG makes recommendations to build capacity for the psychosocial care of HCT patients and to more fully integrate the social worker as a core member of the HCT team. The SWG created a Blood and Marrow Transplant (BMT) Clinical Social Worker role description that can be used by transplant centers to educate healthcare professionals, benchmark utilization of clinical social workers, and improve comprehensive psychosocial health programs. Copyright © 2018 The American Society for Blood and Marrow Transplantation. Published by

Seasonal variation in the incidence of double broods: The date hypothesis fits better than the quality hypothesis

NARCIS (Netherlands)

Verboven, N.; Verhulst, S.

1996-01-01

1. In three great tit (Parus major) populations the probability that a pair starts a second clutch, a clutch produced after a successful first brood, varied between years and areas but generally declined through the breeding season. 2. By exchanging first clutches between early and late breeding

Seasonal variation in the incidence of double broods : The date hypothesis fits better than the quality hypothesis

NARCIS (Netherlands)

Verboven, N; Verhulst, S

1. In three great tit (Parus major) populations the probability that a pair starts a second clutch, a clutch produced after a successful first brood, varied between years and areas but generally declined through the breeding season. 2. By exchanging first clutches between early and late breeding

SENSITIVITY OF NEST SUCCESS, YOUNG FLEDGED, AND PROBABILITY OF RENESTING TO SEASONAL FECUNDITY IN MULTI-BROODED SPECIES

Science.gov (United States)

A considerable number of avian species can produce multiple broods within a season. Seasonal fecundity in these species can vary by changes in the number of young fledged per nest, the probability of a successful nest, and the probability of initiating additional nests (e.g., re...

La eliminación higiénica de la cría congelada no predice caracteres de resistencia ante Varroa en las poblaciones no seleccionadas

NARCIS (Netherlands)

Leclercq, Gil; Blacquière, Tjeerd; Gengler, Nicolas; Francis, Frédéric

2018-01-01

In honey bees (Apis mellifera L.), hygienic behavior of workers against Varroa destructor provides the colonies with some resistance to this parasite. The removal of freeze-killed brood (FKB) has often been used as a proxy to assess the removal of Varroa-infested brood. The question is whether this

A new species of brooding Psolidae (Echinodermata: Holothuroidea) from deep-sea off Argentina, Southwestern Atlantic Ocean

Science.gov (United States)

Martinez, Mariano I.; Penchaszadeh, Pablo E.

2017-12-01

This paper describes a new species of Psolus (Holothuroidea, Echinodermata), P. lawrencei sp. nov., (19 specimens) found in the deep sea (308-1398 m) in the Southwestern Atlantic Ocean (SWAO) (around 38°S-54°W) with brooders (up to 3.15 mm) in the tentacles of females and a penis-like genital papilla on males. The presence of dorsal scales, the concave shape of the ossicles with a bridge, the distribution of podia on the dorsal side and the absence of large and conspicuous oral and anal valves are unique for this species. Furthermore, this is the first species of this genus found outside Antarctica that broods between its tentacles. The paper also reviews the reproductive, brooding development and morphological characteristics of P. lawrencei sp. nov. and compares them with those of several members of the family Psolidae. Finally, a possible connectivity between the deep-sea populations in the SWAO and in Antarctica is considered based on the appearance of a similar reproductive pattern in populations found in both areas, which suggests a past or present connection between these regions.

Increased host tolerance of multiple cuckoo eggs leads to higher fledging success of the brood parasite

Czech Academy of Sciences Publication Activity Database

Moskát, C.; Hauber, M. E.; Avilés, J. M.; Bán, M.; Hargitai, R.; Honza, Marcel

2009-01-01

Roč. 77, č. 5 (2009), s. 1281-1290 ISSN 0003-3472 R&D Projects: GA AV ČR IAA600930903 Grant - others:OTKA(HU) 48397 Institutional research plan: CEZ:AV0Z60930519 Keywords : brood parasitism * common cuckoo * egg recognition * egg rejection * evictor chick * mimicry * reproductive success Subject RIV: EG - Zoology Impact factor: 2.890, year: 2009

Selection of Apis mellifera workers by the parasitic mite Varroa destructor using host cuticular hydrocarbons.

Science.gov (United States)

Del Piccolo, F; Nazzi, F; Della Vedova, G; Milani, N

2010-05-01

The parasitic mite, Varroa destructor, is the most important threat for apiculture in most bee-keeping areas of the world. The mite is carried to the bee brood cell, where it reproduces, by a nurse bee; therefore the selection of the bee stage by the parasite could influence its reproductive success. This study investigates the role of the cuticular hydrocarbons of the European honeybee (Apis mellifera) in host-selection by the mite. Preliminary laboratory bioassays confirmed the preference of the varroa mite for nurse bees over pollen foragers. GC-MS analysis of nurse and pollen bees revealed differences in the cuticular hydrocarbons of the two stages; in particular, it appeared that pollen bees have more (Z)-8-heptadecene than nurse bees. Laboratory experiments showed that treatment of nurse bees with 100 ng of the pure compound makes them repellent to the varroa mite. These results suggest that the mite can exploit the differences in the cuticular composition of its host for a refined selection that allows it to reach a brood cell and start reproduction. The biological activity of the alkene encourages further investigations for the development of novel control techniques based on this compound.

Biodosimetry of Chernobyl cleanup workers from Estonia and Latvia using the glycophorin A in vivo somatic cell mutation assay

International Nuclear Information System (INIS)

Bigbee, W.L.; Jensen, R.H.; Veidebaum, T.

1997-01-01

The reactor accident at Chernobyl in 1986 necessitated a massive environmental cleanup that involved over 600,000 workers from all 15 Republics of the former Soviet Union. To determine whether the whole-body radiation received by workers in the course of these decontamination activities resulted in a detectable biological response, over 1,500 blood samples were obtained from cleanup workers sent from two Baltic countries, Estonia and Latvia. Here we report the results of studies of biodosimetry using the glycophorin A (GPA) locus in vivo somatic cell mutation assay applied to 734 blood samples from these workers, to 51 control samples from unexposed Baltic populations and to 94 samples from historical U.S. controls. The data reveal inconsistent evidence that the protracted radiation exposures received by these workers resulted in a significant dose-associated increase in GPA locus mutations compared with the controls. Taken together, these data suggest that the average radiation exposure to these workers does not greatly exceed 10 cGy, the minimum levels at which radiation effects might be detectable by the assay. Although the protracted nature of the exposure may have reduced the efficiency of induction of GPA locus mutations, it is likely that the estimated physical doses for these cleanup worker populations (median reported dose 9.5 cGy) were too low to result in radiation damage to erythroid stem cells that can be detected reliably by this method. 25 refs., 2 figs., 3 tabs

CONTENT AND FATTY ACID COMPOSITION OF ESTERIFIED CHOLESTEROL OF LIVER AND REPRODUCTION ABILITY OF BROOD CARP (CYPRINUS CARPIO CARPIO WITH DIFFERENT LEVELS OF VITAMIN A IN FORMULATED FEED

Directory of Open Access Journals (Sweden)

I. Hrytsyniak

2015-09-01

Full Text Available Purpose. To investigate the effect of increased amounts of vitamin A in the diet on the fatty acid composition of esterified cholesterol of liver and reproduction ability of brood carp females and males. Methodology. The experiment was conducted in pre-spawning period using three groups of brood carp. The control group of carp received standard granulated feed. Experimental groups of brood carps additionally received retynilatsetat in the composition of the above-mentioned fodder. Findings. It was found that the liver of females and males of brood carp of experimental groups, which received vitamin A at a quantity of 2500 and 5000 IU/kg of feed in the composition of standard granulated formulated feed during pre-spawning period had shown a dose-dependent reduction in the content of esterified cholesterol. At the same time, the level of monounsaturated fatty acids of n-9 family decreases significantly and dose-dependently in its fatty acid composition, however, there is an increase in the level of saturated fatty acids with paired and unpaired quantities of carbon atoms in the chain as well as polyunsaturated fatty acids of n-6 family and especially n-3 family. Females of brood carp in the experimental groups, which were fed with additional vitamin A at a quantity of 2500 and 5000 IU/kg of standard granulated formulated feed during pre-spawning period, had an increase in working and relative fecundity, while males had an increase in sperm volume. At the same time, the output of larvae from eggs increases significantly and dose-dependently. Originality. For the first time it was found that the liver of brood carp females and males, which received increased quantities of vitamin A in the composition of standard granulated formulated feed during pre-spawning period, had the reduction in the content of esterified cholesterol. the level of monounsaturated fatty acids of n-9 family decreases significantly and dose-dependently in its fatty acid

Relationship between radiation dose and changes of blood cells in medical diagnostic X-ray workers in China

International Nuclear Information System (INIS)

Zhao Wenzheng

1984-01-01

The hematological changes of 2867 cases of medical X-ray workers and 1152 cases of non-X-ray medical workers were compared. It was shown that the total number of leukocytes, the numbers of neutrophils, lymphocytes and platelets were significantly lower in X-ray workers than those in controls. However, the percentages of monocytes, eosinophils, basophils and the concentration of hemoglobin were higher in the irradiated group. the difference between the two groups was statistically significant. The degree of changes in the number of blood cells was dose-dependent. A negative correlation could be found between the changes of leukocyte and neutrophil counts and cumulative dose (<250 mGy), annual dose (<15 mGy/a) and length of service of the X-ray workers; and a positive correlation existed between the percentages of basophils, eosinophils and monocytes, and the radiation dose. The abnormality rate of blood picture in the irradiated group was higher than that in the control group. Most X-ray workers with abnormal blood picture were distributed in low-dose group. The data also showed that radiation effect on male X-ray workers was greater than that on female workers. (Author)

Frequencies of chromosome aberration on radiation workers

International Nuclear Information System (INIS)

Yanti Lusiyanti; Zubaidah Alatas

2016-01-01

Radiation exposure of the body can cause damage to the genetic material in cells (cytogenetic) in the form of changes in the structure or chromosomal aberrations in peripheral blood lymphocytes. Chromosomal aberrations can be unstable as dicentric and ring chromosomes, and is stable as translocation. Dicentric chromosome is the gold standard biomarker due to radiation exposure, and chromosome translocation is a biomarker for retrospective biodosimetry. The aim of this studi is to conduct examination of chromosomal aberrations in the radiation worker to determine the potential damage of cell that may arise due to occupational radiation exposure. The examination have been carried out on blood samples from 55 radiation workers in the range of 5-30 year of service. Chromosome aberration frequency measurement starts with blood sampling, culturing, harvesting, slide preparations, and lymphocyte chromosome staining with Giemsa and painting with Fluorescence In Situ Hybridization (FISH) technique. The results showed that chromosomal translocations are not found in blood samples radiation workers and dicentric chromosomes found only on 2 blood samples of radiation workers with a frequency of 0.001/cell. The frequency of chromosomal aberrations in the blood cells such workers within normal limits and this means that the workers have been implemented a radiation safety aspects very well. (author)

Analysis of South Carolina hydrogen and fuel cell workers views and opinion leadership behavior: A waiting opportunity?

Energy Technology Data Exchange (ETDEWEB)

Besley, John C. [School of Journalism and Mass Communications, University of South Carolina, Columbia, SC 29205 (United States); Baxter-Clemmons, Shannon [South Carolina Hydrogen Fuel Cell Alliance, P.O. Box 12302, Columbia, SC 29201 (United States)

2010-08-15

The current study uses quantitative survey results to explore what a near census of hydrogen and fuel cell (HFC) workers in South Carolina (n = 70) say about their HFC experiences and the degree to which these workers can be expected to act as opinion leaders for the field. In general, these workers say they are positive about the environmental, national security, and economic potential of HFC technologies. They further see HFC technologies as having small and manageable levels of risk. A number of these workers exhibit characteristics associated with both issue-specific and general opinion leadership. Issue-specific leadership and positive views about HFC technology were associated with higher levels of self-reported technology-related interpersonal discussion. The study concludes that the existence of workers with positive HFC experiences and a demonstrated interest in telling others about their experiences may represent an opportunity for those charged with promoting HFC development and adoption. Future efforts should explore how HFC workers could be effectively integrated into such efforts as a means of reaching difficult to reach audiences. (author)

Subsocial behaviour and brood adoption in mixed-species colonies of two theridiid spiders

DEFF Research Database (Denmark)

Grinsted, Lena; Agnarsson, Ingi; Bilde, Trine

2012-01-01

, aggression and cooperation through behavioural experiments and examine the potential for adoption of foreign brood. Morphological and genetic analyses confirmed that colonies consisted of two related species Chikunia nigra (O.P. Cambridge, 1880) new combination (previously Chrysso nigra) and a yet...... as in territorial, colonial spiders. Mixed species spider colonies, involving closely related species, have rarely been documented. We examined social interactions in newly discovered mixed-species colonies of theridiid spiders on Bali, Indonesia. Our aim was to test the degree of intra- and interspecific tolerance...

Octanoic acid confers to royal jelly varroa-repellent properties

Science.gov (United States)

Nazzi, Francesco; Bortolomeazzi, Renzo; Della Vedova, Giorgio; Del Piccolo, Fabio; Annoscia, Desiderato; Milani, Norberto

2009-02-01

The mite Varroa destructor Anderson & Trueman is a parasite of the honeybee Apis mellifera L. and represents a major threat for apiculture in the Western world. Reproduction takes place only inside bee brood cells that are invaded just before sealing; drone cells are preferred over worker cells, whereas queen cells are not normally invaded. Lower incidence of mites in queen cells is at least partly due to the deterrent activity of royal jelly. In this study, the repellent properties of royal jelly were investigated using a lab bioassay. Chemical analysis showed that octanoic acid is a major volatile component of royal jelly; by contrast, the concentration is much lower in drone and worker larval food. Bioassays, carried out under lab conditions, demonstrated that octanoic acid is repellent to the mite. Field studies in bee colonies confirmed that the compound may interfere with the process of cell invasion by the mite.

Inbreeding and brood stock management

National Research Council Canada - National Science Library

Tave, Douglas

1999-01-01

This manual, written for extension workers, aquaculturists, and those who work with inbreeding in cultured fish populations and describes management techniques that can be used to prevent or minimize inbreeding...

Assessment of DNA damage in radiation workers by using single cell gel electrophoresis

International Nuclear Information System (INIS)

Jia Lili; Zhang Tao; Yang Yonghua; Wang Yan; Du Liqing; Cao Jia; Wang Hong; Liu Qiang; Fan Feiyue

2010-01-01

Objective: To assess the DNA damage of radiation workers in different grade hospitals, and to explore the correlation between the types of work or work time and the levels of DNA damage. Methods: DNA single strand break were detected by using alkaline single cell gel electrophoresis (SCGE), and the comet was analyzed with CASP (Comet Assay Software Project). TDNA%, TL, TM and OTM were calculated. Results: The parameters of SCGE in the radiation group were higher than those of control group (F=3.93, P<0.01). The significant difference was found not only among the different types of work or different work time, but also among the different grade hospitals (F=1.83, 1.91, P<0.05). Conclusions: Various levels of DNA damage could be detected in the radiation workers of the two hospitals. DNA damage of radiation workers is less serious in the higher-grade hospital than the lower grade one. Different types of work or work time might affect the DNA damage level. (authors)

Dermal Exposure to Jet Fuel JP-8 Significantly Contributes to the Production of Urinary Naphthols in Fuel-Cell Maintenance Workers

OpenAIRE

Chao, Yi-Chun E.; Kupper, Lawrence L.; Serdar, Berrin; Egeghy, Peter P.; Rappaport, Stephen M.; Nylander-French, Leena A.

2005-01-01

Jet propulsion fuel 8 (JP-8) is the major jet fuel used worldwide and has been recognized as a major source of chemical exposure, both inhalation and dermal, for fuel-cell maintenance workers. We investigated the contributions of dermal and inhalation exposure to JP-8 to the total body dose of U.S. Air Force fuel-cell maintenance workers using naphthalene as a surrogate for JP-8 exposure. Dermal, breathing zone, and exhaled breath measurements of naphthalene were obtained using tape-strip sam...

Warm springs, early lay dates, and double brooding in a North American migratory songbird, the black-throated blue warbler.

Directory of Open Access Journals (Sweden)

Andrea K Townsend

Full Text Available Numerous studies have correlated the advancement of lay date in birds with warming climate trends, yet the fitness effects associated with this phenological response have been examined in only a small number of species. Most of these species--primarily insectivorous cavity nesters in Europe--exhibit fitness declines associated with increasing asynchrony with prey. Here, we use 25 years of demographic data, collected from 1986 to 2010, to examine the effects of spring temperature on breeding initiation date, double brooding, and annual fecundity in a Nearctic-Neotropical migratory songbird, the black-throated blue warbler (Setophaga caerulescens. Data were collected from birds breeding at the Hubbard Brook Experimental Forest, New Hampshire, USA, where long-term trends toward warmer springs have been recorded. We found that black-throated blue warblers initiated breeding earlier in warmer springs, that early breeders were more likely to attempt a second brood than those starting later in the season, and that double brooding and lay date were linked to higher annual fecundity. Accordingly, we found selection favored earlier breeding in most years. However, in contrast to studies of several other long-distance migratory species in Europe, this selection pressure was not stronger in warmer springs, indicating that these warblers were able to adjust mean lay date appropriately to substantial inter-annual variation in spring temperature. Our results suggest that this North American migratory songbird might not experience the same fecundity declines as songbirds that are unable to adjust their timing of breeding in pace with spring temperatures.

Varroa destructor induces changes in the expression of immunity-related genes during the development of Apis mellifera worker and drone broods.

Science.gov (United States)

Zaobidna, Ewa A; Żółtowska, Krystyna; Łopieńska-Biernat, Elżbieta

2017-12-20

The ectoparasitic mite Varroa destructor has emerged as the major pest of honeybees. Despite extensive research efforts, the pathogenesis of varroosis has not been fully explained. Earlier studies suggested that V. destructor infestation leads to the suppression of the host's immune system. The aim of this study was to analyze the immune responses of 14 genes in the Toll signal transduction pathways, including effector genes of antimicrobial peptides (AMPs), in developing Apis mellifera workers and drones infested with V. destructor. Four developmental stages (L5 larvae, prepupae, and 2 pupal stages) and newly emerged imagines were analyzed. In workers, the most significant changes were observed in L5 larvae in the initial stages of infestation. A significant increase in the relative expression of 10 of the 14 analyzed genes, including defensin-1 and defensin-2, was observed in infested bees relative to non-infested individuals. The immune response in drones developed at a slower rate. The expression of genes regulating cytoplasmic signal transduction increased in prepupae, whereas the expression of defensin-1 and defensin-2 effector genes increased in P3 pupae with red eyes. The expression of many immunity-related genes was silenced in successive life stages and in imagines, and it was more profound in workers than in drones. The results indicate that V. destructor significantly influences immune responses regulated by the Toll signal transduction pathway in bees. In infested bees, the observed changes in Toll pathway genes varied between life stages and the sexes.

Genotoxic damage in auto body shop workers.

Science.gov (United States)

Siebel, Anna Maria; Basso da Silva, Luciano

2010-10-01

Some studies have shown increased DNA damage among car painters, but other professionals working in auto body and paint shops have not been extensively assessed. The aim of this study was to assess DNA damage in different types of auto body shop workers by measuring micronucleus (MN) levels in exfoliated buccal cells. The mean number of cells with MN per 2000 exfoliated buccal cells was analyzed in three groups of male workers: auto body repair technicians, painters, and office workers (control group). All participants answered a questionnaire inquiring about age, smoking habits, alcohol consumption, work practices, occupational exposure time, job activities, and use of protective equipment. The mean number of cells with MN was 3.50 ± 1.50 in auto body painters, 3.91 ± 2.10 in auto body repair technicians, and 0.80 ± 0.78 in office workers, with a significant difference between the control group and the two other groups (p = 0.0001). Age, occupational exposure time, use of protective masks, alcohol consumption, and smoking habit did not affect MN results. The findings indicate that technicians and painters working in auto body shops are at risk for genotoxic damage, while office workers seem to be protected.

Natural Larval Diet Differently Influences the Pattern of Developmental Changes in DNA 5-Methylcytosine Levels in Apis mellifera Queens as Compared with Workers and Drones.

Science.gov (United States)

Strachecka, A; Olszewski, K; Bajda, M; Demetraki-Paleolog, J

2015-08-01

The principal mechanism of gene activation/silencing is DNA 5-methylcytosine methylation. This study was aimed at determining global DNA methylation levels in larvae, prepupae, pupae, and 1-day-old adults of Apis mellifera queens, workers and drones. The Imprint Methylated DNA Quantification Kit MDQ1 was used. Percentages of DNA 5-methylcytosine were low and relatively similar in the larvae of all the castes until 4th day of larval development (3-5%). However, they were higher in the drone and worker larvae than in the queen larvae. Generally, the developmental patterns of changes in the DNA methylation levels were different in the queens in comparison with the drones and workers. While methylation increased in the queens, it decreased in the drones and workers. Methylated DNA methylcytosine percentages and weights in the queen prepupae (15%, 9.18 ng) and pupae (21%, 10.74 ng) were, respectively, three and four times higher than in the worker/drone brood of the same age (2.5-4%, 0.03-0.07 ng). Only in the queens, after a substantial increase, did DNA methylation decrease almost twice between the pupal stage and queen emergence (from 21% and 10.74 ng to 12% and 6.78 ng). This finding seems very interesting, particularly for experimental gerontology.

Genotoxic Effects of Exposure to Gasoline Fumes on Petrol Pump Workers.

Science.gov (United States)

Shaikh, Amrin; Barot, Darshana; Chandel, Divya

2018-04-01

Petrol pump workers are occupationally exposed to gasoline and its fumes consisting of several mutagenic chemicals. To evaluate the genotoxic effects of exposure to gasoline fumes on petrol pump workers. The study groups included 70 petrol pump workers (exposed group) and 70 healthy age-matched individuals with no known exposure (comparison group). Buccal micronucleus cytome assay (BMCyt) was performed to check the genotoxicity caused due to inhalation of gasoline fumes. The frequencies of micronucleated cells, nuclear bud, condensed chromatin cells, karyorrhectic cells, pyknotic cells, and karyolytic cells were significantly higher in the exposed workers compared to the comparison group. Exposure to gasoline fumes is associated with increased frequency of cell abnormalities. This may lead to various health consequences including cancer in those occupationally exposed to gasoline fumes.

Assessment of DNA damage in ceramic workers.

Science.gov (United States)

Anlar, Hatice Gul; Taner, Gokce; Bacanli, Merve; Iritas, Servet; Kurt, Turker; Tutkun, Engin; Yilmaz, Omer Hinc; Basaran, Nursen

2018-02-24

It is known that ceramic workers are potentially exposed to complex mixture of chemicals such as silica, inorganic lead, lime, beryllium and aluminum that can be associated with an increased risk of several diseases. All operations in the ceramic industries such as mixing, moulding, casting, shaking out and finishing jobs, have been associated with the higher exposure levels and in most of the silica-related industries, average overall exposure exceeded permissible exposure levels for respirable crystalline silica. The aim of this study was to evaluate the possible genotoxic damage in ceramic workers exposed to complex mixture of chemicals mainly crystalline silica. For this purpose, the blood and buccal epithelial cell samples were taken from the ceramic workers (n = 99) and their controls (n = 81). The genotoxicity was assessed by the alkaline comet assay in isolated lymphocytes and whole blood. Micronucleus (MN), binucleated (BN), pyknotic (PYC), condensed chromatin (CC), karyolytic (KYL), karyorrhectic (KHC) and nuclear bud (NBUD) frequencies in buccal epithelial cells and plasma 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) levels were also evaluated. In the study, 38 workers were diagnosed with silicosis, 9 workers were suspected to have silicosis, whereas 52 workers were found to be healthy. DNA damage in blood and lymphocytes; MN, CC + KHC, PYC frequencies in buccal epithelial cells and 8-oxodG levels in plasma were increased in workers compared to their controls. These results showed that occupational chemical mixture exposure in ceramic industry may cause genotoxic damage that can lead to important health problems in the workers.

Preparation of Single-cohort Colonies and Hormone Treatment of Worker Honeybees to Analyze Physiology Associated with Role and/or Endocrine System.

Science.gov (United States)

Ueno, Takayuki; Kawasaki, Kiyoshi; Kubo, Takeo

2016-09-06

Honeybee workers are engaged in various tasks related to maintaining colony activity. The tasks of the workers change according to their age (age-related division of labor). Young workers are engaged in nursing the brood (nurse bees), while older workers are engaged in foraging for nectar and pollen (foragers). The physiology of the workers changes in association with this role shift. For example, the main function of the hypopharyngeal glands (HPGs) changes from the secretion of major royal jelly proteins (MRJPs) to the secretion of carbohydrate-metabolizing enzymes. Because worker tasks change as the workers age in typical colonies, it is difficult to discriminate the physiological changes that occur with aging from those that occur with the role shift. To study the physiological changes in worker tissues, including the HPGs, in association with the role shift, it would be useful to manipulate the honeybee colony population by preparing single-cohort colonies in which workers of almost the same age perform different tasks. Here we describe a detailed protocol for preparing single-cohort colonies for this analysis. Six to eight days after single-cohort colony preparation, precocious foragers that perform foraging tasks earlier than usual appear in the colony. Representative results indicated role-associated changes in HPG gene expression, suggesting role-associated HPG function. In addition to manipulating the colony population, analysis of the endocrine system is important for investigating role-associated physiology. Here, we also describe a detailed protocol for treating workers with 20-hydroxyecdysone (20E), an active form of ecdysone, and methoprene, a juvenile hormone analogue. The survival rate of treated bees was sufficient to examine gene expression in the HPGs. Gene expression changes were observed in response to 20E- and/or methoprene-treatment, suggesting that hormone treatments induce physiological changes of the HPGs. The protocol for hormone

Critical PO2 of developing Megachile rotundata, the alfalfa leaf-cutting bee

Science.gov (United States)

The alfalfa leaf-cutting bee, Megachile rotundata, is a solitary, cavity-nesting bee. Juvenile bees develop inside brood cells constructed out of leaf pieces. During development inside the brood cell, pre-pupae may experience hypoxic conditions from both the cavity nesting behavior and brood cell ...

Genotoxic Effects of Exposure to Gasoline Fumes on Petrol Pump Workers

Directory of Open Access Journals (Sweden)

Amrin Shaikh

2018-04-01

Full Text Available Background: Petrol pump workers are occupationally exposed to gasoline and its fumes consisting of several mutagenic chemicals. Objective: To evaluate the genotoxic effects of exposure to gasoline fumes on petrol pump workers. Methods: The study groups included 70 petrol pump workers (exposed group and 70 healthy age-matched individuals with no known exposure (comparison group. Buccal micronucleus cytome assay (BMCyt was performed to check the genotoxicity caused due to inhalation of gasoline fumes. Results: The frequencies of micronucleated cells, nuclear bud, condensed chromatin cells, karyorrhectic cells, pyknotic cells, and karyolytic cells were significantly higher in the exposed workers compared to the comparison group. Conclusion: Exposure to gasoline fumes is associated with increased frequency of cell abnormalities. This may lead to various health consequences including cancer in those occupationally exposed to gasoline fumes.

Brood stock formation of the hermaphrodite finfish species Pagellus erythrinus (common Pandora from fish reared in captivity

Directory of Open Access Journals (Sweden)

S.D. KLAOUDATOS

2004-06-01

Full Text Available Formation of brood stock is considered to be one of the most important operations in order to acquire eggs and fry from any promising candidate finfish species for aquaculture production. The sex reversal observed in hermaphrodite species adds to confusion and creates additional complications in forming a brood stock. The present study describes the efforts and the results of the brood stock formation of the hermaphrodite finfish species Pagellus erythrinus (common Pandora from individuals aged between 4 and 5 years (TL>300mm reared in floating cages. Six groups were formed (50 fish/group in all of which females were present comprising 20 to 40% of the population. The presence of females was in contrast to the literature, which reported that sex reversal of the common Pandora is complete in naturally occurring populations with the absence of females in sizes of a total length greater than 220mm, indicating that in captivity sex reversal is not complete for this species. Four of the groups formed spawned under natural environmental conditions without hormonal treatment and the other two groups were administered a different dosage (250 and 500 IU/kg of Human Chorionic Gonadotropin (HCG to induce spawning. The reproductive period started in the middle of May and ended at the beginning of July and spontaneous spawning occurred in all groups. Egg release lasted for a mean period of one month for the groups that spawned without hormonal treatment with no significant difference in the number of viable eggs between groups. The groups that spawned under hormonal treatment released eggs for a period of six and seven days, for the group that spawned under the high and low hormonal treatment, respectively, with no significant difference in the number of viable eggs between them. The hormonal induced spawning resulted in egg release within a short period of time ideal for a hatchery. However, the number of viable eggs produced was significantly lower

Uncovering Dangerous Cheats: How Do Avian Hosts Recognize Adult Brood Parasites?

Science.gov (United States)

Trnka, Alfréd; Prokop, Pavol; Grim, Tomáš

2012-01-01

Background Co-evolutionary struggles between dangerous enemies (e.g., brood parasites) and their victims (hosts) lead to the emergence of sophisticated adaptations and counter-adaptations. Salient host tricks to reduce parasitism costs include, as front line defence, adult enemy discrimination. In contrast to the well studied egg stage, investigations addressing the specific cues for adult enemy recognition are rare. Previous studies have suggested barred underparts and yellow eyes may provide cues for the recognition of cuckoos Cuculus canorus by their hosts; however, no study to date has examined the role of the two cues simultaneously under a consistent experimental paradigm. Methodology/Principal Findings We modify and extend previous work using a novel experimental approach – custom-made dummies with various combinations of hypothesized recognition cues. The salient recognition cue turned out to be the yellow eye. Barred underparts, the only trait examined previously, had a statistically significant but small effect on host aggression highlighting the importance of effect size vs. statistical significance. Conclusion Relative importance of eye vs. underpart phenotypes may reflect ecological context of host-parasite interaction: yellow eyes are conspicuous from the typical direction of host arrival (from above), whereas barred underparts are poorly visible (being visually blocked by the upper part of the cuckoo's body). This visual constraint may reduce usefulness of barred underparts as a reliable recognition cue under a typical situation near host nests. We propose a novel hypothesis that recognition cues for enemy detection can vary in a context-dependent manner (e.g., depending on whether the enemy is approached from below or from above). Further we suggest a particular cue can trigger fear reactions (escape) in some hosts/populations whereas the same cue can trigger aggression (attack) in other hosts/populations depending on presence/absence of dangerous

Application of liquid-based cytology preparation in micronucleus assay of exfoliated buccal epithelial cells in road construction workers.

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Arul, P

2017-01-01

Asphalts are bitumens that consist of complex of hydrocarbon mixtures and it is used mainly in road construction and maintenance. This study was undertaken to evaluate the micronucleus (MN) assay of exfoliated buccal epithelial cells in road construction workers using liquid-based cytology (LBC) preparation. Three different stains (May-Grunwald Giemsa, hematoxylin and eosin, and Papanicolaou) were used to evaluate the frequency of MN in exfoliated buccal epithelial of 100 participants (fifty road construction workers and fifty administrative staff) using LBC preparation. Statistical analysis was performed with Student's t-test, and Proad construction exhibit a higher frequency of MN in exfoliated buccal epithelial cells and they are under the significant risk of cytogenetic damage. LBC preparation has potential application for the evaluation of frequency of MN. This technique may be advocated in those who are occupationally exposed to potentially carcinogenic agents in view of improvement in the smear quality and visualization of cell morphology.

Aging and demographic plasticity in response to experimental age structures in honeybees (Apis mellifera L).

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Rueppell, Olav; Linford, Robyn; Gardner, Preston; Coleman, Jennifer; Fine, Kari

2008-08-01

Honeybee colonies are highly integrated functional units characterized by a pronounced division of labor. Division of labor among workers is mainly age-based, with younger individuals focusing on in-hive tasks and older workers performing the more hazardous foraging activities. Thus, experimental disruption of the age composition of the worker hive population is expected to have profound consequences for colony function. Adaptive demography theory predicts that the natural hive age composition represents a colony-level adaptation and thus results in optimal hive performance. Alternatively, the hive age composition may be an epiphenomenon, resulting from individual life history optimization. We addressed these predictions by comparing individual worker longevity and brood production in hives that were composed of a single age cohort, two distinct age cohorts, and hives that had a continuous, natural age distribution. Four experimental replicates showed that colonies with a natural age composition did not consistently have a higher life expectancy and/or brood production than the single cohort or double cohort hives. Instead, a complex interplay of age structure, environmental conditions, colony size, brood production, and individual mortality emerged. A general trade-off between worker life expectancy and colony productivity was apparent, and the transition from in-hive tasks to foraging was the most significant predictor of worker lifespan irrespective of the colony age structure. We conclude that the natural age structure of honeybee hives is not a colony-level adaptation. Furthermore, our results show that honeybees exhibit pronounced demographic plasticity in addition to behavioral plasticity to react to demographic disturbances of their societies.

Elevated temperature alters the lunar timing of Planulation in the brooding coral Pocillopora damicornis.

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Camerron M Crowder

Full Text Available Reproductive timing in corals is associated with environmental variables including temperature, lunar periodicity, and seasonality. Although it is clear that these variables are interrelated, it remains unknown if one variable in particular acts as the proximate signaler for gamete and or larval release. Furthermore, in an era of global warming, the degree to which increases in ocean temperatures will disrupt normal reproductive patterns in corals remains unknown. Pocillopora damicornis, a brooding coral widely distributed in the Indo-Pacific, has been the subject of multiple reproductive ecology studies that show correlations between temperature, lunar periodicity, and reproductive timing. However, to date, no study has empirically measured changes in reproductive timing associated with increased seawater temperature. In this study, the effect of increased seawater temperature on the timing of planula release was examined during the lunar cycles of March and June 2012. Twelve brooding corals were removed from Hobihu reef in Nanwan Bay, southern Taiwan and placed in 23 and 28°C controlled temperature treatment tanks. For both seasons, the timing of planulation was found to be plastic, with the high temperature treatment resulting in significantly earlier peaks of planula release compared to the low temperature treatment. This suggests that temperature alone can influence the timing of larval release in Pocillopora damicornis in Nanwan Bay. Therefore, it is expected that continued increases in ocean temperature will result in earlier timing of reproductive events in corals, which may lead to either variations in reproductive success or phenotypic acclimatization.

Obligate brood parasites show more functionally effective innate immune responses: an eco-immunological hypothesis

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Hahn, D. Caldwell; Summers, Scott G.; Genovese, Kenneth J.; He, Haiqi; Kogut, Michael H.

2013-01-01

Immune adaptations of obligate brood parasites attracted interest when three New World cowbird species (Passeriformes, Icteridae, genus Molothrus) proved unusually resistant to West Nile virus. We have used cowbirds as models to investigate the eco-immunological hypothesis that species in parasite-rich environments characteristically have enhanced immunity as a life history adaptation. As part of an ongoing program to understand the cowbird immune system, in this study we measured degranulation and oxidative burst, two fundamental responses of the innate immune system. Innate immunity provides non-specific, fast-acting defenses against a variety of invading pathogens, and we hypothesized that innate immunity experiences particularly strong selection in cowbirds, because their life history strategy exposes them to diverse novel and unpredictable parasites. We compared the relative effectiveness of degranulation and oxidative burst responses in two cowbird species and one related, non-parasitic species. Both innate immune defenses were significantly more functionally efficient in the two parasitic cowbird species than in the non-parasitic red-winged blackbird (Icteridae, Agelaius phoeniceus). Additionally, both immune defenses were more functionally efficient in the brown-headed cowbird (M. ater), an extreme host-generalist brood parasite, than in the bronzed cowbird (M. aeneus), a moderate host-specialist with lower exposure to other species and their parasites. Thus the relative effectiveness of these two innate immune responses corresponds to the diversity of parasites in the niche of each species and to their relative resistance to WNV. This study is the first use of these two specialized assays in a comparative immunology study of wild avian species.

A Nightmare for Males? A Maternally Transmitted Male-Killing Bacterium and Strong Female Bias in a Green Lacewing Population.

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Masayuki Hayashi

Full Text Available For maternally transmitted microbes, a female-biased host sex ratio is of reproductive advantage. Here we found a strong female bias in a field population of the green lacewing, Mallada desjardinsi (Insecta; Neuroptera. This bias was attributed to the predominance of individuals harboring a maternally inherited male-killing bacterium that was phylogenetically closely related to the plant-pathogenic Spiroplasma phoeniceum and Spiroplasma kunkelii. Among 35 laboratory-reared broods produced by wild-caught females, 21 broods (60%-all infected with Spiroplasma-consisted of only females (940 individuals. Among 14 broods consisting of both males and females (516 and 635 individuals, respectively, 4 broods were doubly infected with Spiroplasma and Rickettsia, 6 broods were singly infected with Rickettsia, and 3 broods were uninfected (remaining one brood was unknown. Mortality during embryonic and larval development was prominent in all-female broods but not in normal sex ratio broods. Following antibiotic treatment on all-female broods, mortality was significantly reduced and the sex ratio was restored to 1:1. Strong expression and high prevalence of this male-killer is remarkable considering its low density (~10-5-10-4 cells per host mitochondrial gene copy based on quantitative PCR. In addition, a bacterium closely related to Rickettsia bellii was present in 25 of 34 broods (73.5%, irrespective of the sex ratio, with the infection density comparable to other cases of endosymbiosis (~10-2-10-1 cells per mitochondrial gene copy. Higher density of Rickettsia than Spiroplasma was also demonstrated by electron microscopy which visualized both Spiroplasma-like cells and Rickettsia-like cells inside and outside the ovarian cells.

Discordancy or template-based recognition? Dissecting the cognitive basis of the rejection of foreign eggs in hosts of avian brood parasites

NARCIS (Netherlands)

Moskat, Csaba; Ban, Miklos; Szekely, Tamas; Komdeur, Jan; Lucassen, Rim W. G.; van Boheemen, Lotte A.; Hauber, Mark E.

2010-01-01

Many avian hosts have evolved antiparasite defence mechanisms, including egg rejection, to reduce the costs of brood parasitism. The two main alternative cognitive mechanisms of egg discrimination are thought to be based on the perceived discordancy of eggs in a clutch or the use of recognition

Some lite it hot: the effect of temperature on brood development in the invasive crab Hemigrapsus takanoi (Decapoda: brachyura: Varunidae)

NARCIS (Netherlands)

Brink, van den A.M.; Godschalk, M.; Smaal, A.C.; Lindeboom, H.J.; McLay, C.L.

2013-01-01

The duration of brood development in the introduced crab, Hemigrapsus takanoi in the Oosterschelde, The Netherlands, was compared at three different water temperatures. At 12, 18 and 24°C the females took an average of 32, 11 and 8 days respectively to lay eggs, which took 86, 28 and 18 days

Lazy males and hardworking females? Sexual conflict over parental care in a brood parasite host and its consequences for chick growth

Czech Academy of Sciences Publication Activity Database

Požgayová, Milica; Beňo, Radovan; Procházka, Petr; Jelínek, Václav; Abraham, Marek Mihai; Honza, Marcel

2015-01-01

Roč. 69, č. 6 (2015), s. 1053-1061 ISSN 0340-5443 R&D Projects: GA ČR(CZ) GAP506/12/2404 Institutional support: RVO:68081766 Keywords : Acrocephalus arundinaceus * Brood parasitism * Cuculus canorus * Feeding * Parental investment * Social polygyny Subject RIV: EG - Zoology Impact factor: 2.382, year: 2015

The Impact of Sex Work Interruption on Blood-Derived T Cells in Sex Workers from Nairobi, Kenya.

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Omollo, Kenneth; Boily-Larouche, Geneviève; Lajoie, Julie; Kimani, Makobu; Cheruiyot, Julianna; Kimani, Joshua; Oyugi, Julius; Fowke, Keith Raymond

Unprotected sexual intercourse exposes the female genital tract (FGT) to semen-derived antigens, which leads to a proinflammatory response. Studies have shown that this postcoital inflammatory response can lead to recruitment of activated T cells to the FGT, thereby increasing risk of HIV infection. The purpose of this study was to evaluate the impact of sex work on activation and memory phenotypes of peripheral T cells among female sex workers (FSW) from Nairobi, Kenya. Thirty FSW were recruited from the Pumwani Sex Workers Cohort, 10 in each of the following groups: HIV-exposed seronegative (at least 7 years in active sex work), HIV positive, and New Negative (HIV negative, less than 3 years in active sex work). Blood was obtained at three different phases (active sex work, abstinence from sex work-sex break, and following resumption of sex work). Peripheral blood mononuclear cells were isolated and stained for phenotypic markers (CD3, CD4, CD8, and CD161), memory phenotype markers (CD45RA and CCR7), activation markers (CD69, HLA-DR, and CD95), and the HIV coreceptor (CCR5). T-cell populations were compared between groups. In HIV-positive women, CD8+CCR5+ T cells declined at the sex break period, while CD4+CD161+ T cells increased when returning to sex work. All groups showed no significant changes in systemic T-cell activation markers following the interruption of sex work, however, significant reductions in naive CD8+ T cells were noted. For each of the study points, HIV positives had higher effector memory and CD8+CD95+ T cells and lower naive CD8+ T cells than the HIV-uninfected groups. Interruption of sex work had subtle effects on systemic T-cell memory phenotypes.

Brood removal or queen caging combined with oxalic acid treatment to control varroa mites (Varroa destructor) in honey bee colonies (Apis mellifera)

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Few studies of honey bee colonies exist where varroa mite control is achieved by integrating broodless conditions, through either total brood removal or queen caging, in combination with oxalic acid (OA) applications. We observed significant varroa mortality after applications of OA in obtaining bro...

Primary DNA damage in chrome-plating workers.

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Gambelunghe, A; Piccinini, R; Ambrogi, M; Villarini, M; Moretti, M; Marchetti, C; Abbritti, G; Muzi, G

2003-06-30

In order to evaluate the primary DNA damage due to occupational exposure to chromium (VI), DNA strand-breaks and apoptosis in peripheral lymphocytes were measured in a group of 19 chrome-plating workers. DNA strand-breaks was assessed by alkaline (pH>13) single-cell microgel electrophoresis ('comet') assay, while apoptosis was measured by flow-cytometry after propidium iodide staining of the cells. Concentrations of chromium in urine, erythrocytes and lymphocytes were investigated as biological indicators of exposure. A group of 18 hospital workers (control group I) and another 20 university personnel (control group II) without exposure to chromium were also studied as controls. The results of the study show that chrome-plating workers have higher levels of chromium in urine, erythrocytes and lymphocytes than unexposed workers. Comet tail moment values, assumed as index of DNA damage, are increased in chromium-exposed workers and results are significantly correlated to chromium lymphocyte concentrations. No difference emerged in the percentage of apoptotic nuclei in exposed and unexposed workers. The study confirms that measurements of chromium in erythrocytes and lymphocytes may provide useful information about recent and past exposure to hexavalent chromium at the workplace. The increase in DNA strand-breaks measured by comet assay suggests this test is valid for the biological monitoring of workers exposed to genotoxic compounds such as chromium (VI).

Effects of immunostimulation on social behavior, chemical communication and genome-wide gene expression in honey bee workers (Apis mellifera

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Richard Freddie-Jeanne

2012-10-01

Full Text Available Abstract Background Social insects, such as honey bees, use molecular, physiological and behavioral responses to combat pathogens and parasites. The honey bee genome contains all of the canonical insect immune response pathways, and several studies have demonstrated that pathogens can activate expression of immune effectors. Honey bees also use behavioral responses, termed social immunity, to collectively defend their hives from pathogens and parasites. These responses include hygienic behavior (where workers remove diseased brood and allo-grooming (where workers remove ectoparasites from nestmates. We have previously demonstrated that immunostimulation causes changes in the cuticular hydrocarbon profiles of workers, which results in altered worker-worker social interactions. Thus, cuticular hydrocarbons may enable workers to identify sick nestmates, and adjust their behavior in response. Here, we test the specificity of behavioral, chemical and genomic responses to immunostimulation by challenging workers with a panel of different immune stimulants (saline, Sephadex beads and Gram-negative bacteria E. coli. Results While only bacteria-injected bees elicited altered behavioral responses from healthy nestmates compared to controls, all treatments resulted in significant changes in cuticular hydrocarbon profiles. Immunostimulation caused significant changes in expression of hundreds of genes, the majority of which have not been identified as members of the canonical immune response pathways. Furthermore, several new candidate genes that may play a role in cuticular hydrocarbon biosynthesis were identified. Effects of immune challenge expression of several genes involved in immune response, cuticular hydrocarbon biosynthesis, and the Notch signaling pathway were confirmed using quantitative real-time PCR. Finally, we identified common genes regulated by pathogen challenge in honey bees and other insects. Conclusions These results demonstrate that

The sight of an adult brood parasite near the nest is an insufficient cue for a honeyguide host to reject foreign eggs.

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Tong, Wenfei; Horrocks, Nicholas P C; Spottiswoode, Claire N

2015-07-01

Hosts of brood-parasitic birds typically evolve anti-parasitism defences, including mobbing of parasitic intruders at the nest and the ability to recognize and reject foreign eggs from their clutches. The Greater Honeyguide Indicator indicator is a virulent brood parasite that punctures host eggs and kills host young, and accordingly, a common host, the Little Bee-eater Merops pusillus frequently rejects entire clutches that have been parasitized. We predicted that given the high costs of accidentally rejecting an entire clutch, and that the experimental addition of a foreign egg is insufficient to induce this defence, Bee-eaters require the sight of an adult parasite near the nest as an additional cue for parasitism before they reject a clutch. We found that many Little Bee-eater parents mobbed Greater Honeyguide dummies while ignoring barbet control dummies, showing that they recognized them as a threat. Surprisingly, however, neither a dummy Honeyguide nor the presence of a foreign egg, either separately or in combination, was sufficient to stimulate egg rejection.

The influence of encapsulated embryos on the timing of hatching in the brooding gastropod Crepipatella dilatata

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Andrade-Villagrán, P. V.; Baria, K. S.; Montory, J. A.; Pechenik, J. A.; Chaparro, O. R.

2018-01-01

Encapsulated embryos are generally thought to play an active role in escaping from egg capsules or egg masses. However, for species that brood their egg capsules, the factors controlling the timing of hatching are largely unclear, particularly the degree to which hatching is controlled by the embryos rather than by the mother, and the degree to which the hatching of one egg capsule influences the hatching of sister egg capsules within the same egg mass. We studied aspects of hatching using the direct-developing gastropod Crepipatella dilatata, which includes nurse eggs in its egg capsules and broods clusters of egg capsules for at least several weeks before metamorphosed juveniles are released. Isolated egg capsules were able to hatch successfully, in the absence of the mother. Moreover, the hatching of one capsule did not cause adjacent sister capsules to hatch. Hatched and un-hatched sister egg capsules from the same egg mass differed significantly in the number of metamorphosed juveniles, average shell size, offspring biomass (juveniles + veliger larvae), and the number of nurse eggs remaining per egg capsule. Differences in when egg capsules hatched within a single egg mass were not explained by differences in egg capsule age. Hatching occurred only after most nurse eggs had been ingested, most offspring had metamorphosed into juveniles, and juveniles had reached a mean shell length > 1.36 mm. Whether the mother has any role to play in coordinating the hatching process or juvenile release remains to be determined.

Chromosome breakage in peripheral lymphocytes of thorium workers

International Nuclear Information System (INIS)

Hoegerman, S.F.; Cummins, H.T.

1979-01-01

Cytogenic analysis of 21 thorium workers and 3 controls has not shown a significant elevation in the level of chromosome breakage in the workers' peripheral lymphocytes. The observation of a single dicentric chromosome in 100-cell samples from each of two workers with relatively long periods of occupational exposure and relatively high body burdens suggests, however, that such exposure might result in increases in chromosome aberration frequency

Produção e desenvolvimento de colônias de abelhas africanizadas (Apis mellifera l. a partir de diferentes áreas e idades de cria Production and development of africanized honey bee (Apis mellifera l. colonies departing from different comb brood areas and brood ages

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Roberto Henrique Dias da Silva

2004-04-01

Full Text Available A apicultura brasileira usa da captura de enxames silvestres de abelhas melíferas africanizadas (Apis mellifera L. para repor e/ou aumentar o número de colônias dos apiários, possuindo inconvenientes como a dependência da natureza para captura dos enxames, a heterogeneidade genética das colônias capturadas e a possibilidade desses enxames serem portadores de doenças e parasitas prejudiciais à sanidade das abelhas. O presente trabalho testa e apresenta uma técnica de divisão de colônias de abelhas melíferas africanizadas para a produção de novas colônias fortes em curto espaço de tempo, a partir de recursos mínimos de cera, cria e alimento. Os resultados mostraram que núcleos de A. mellifera formados inicialmente com uma rainha jovem e fecundada, 1 kg de operárias, um quadro de cria fechada, um quadro de favo puxado e vazio e dois quadros com cera alveolada permitem a produção de novas colônias em 42 dias. Portanto, pode-se concluir que a técnica de divisão de colônias por formação de núcleos como descrito acima, oferece aos apicultores uma alternativa viável para a produção e comercialização em larga escala de novas colônias de abelhas melíferas africanizadas.The Brazilian apiculture relies upon collecting wild swarms of Africanized honey bees (Apis mellifera L. to replace and/or increase the number of colonies in the apiaries. This practice brings problems such as dependence on nature to capture any swarm, diverse genetic make-up of the colonies captured and the possibility of these swarms be carrying diseases and parasites harmful to the bees. The present work tests and presents a technique to split colonies of Africanized honey bees to produce new strong colonies in short time, departing from little resources of wax, brood and food stores. Results showed that A. mellifera nuclei formed by a young and mated queen, 1kg of workers, a frame of sealed brood, an empty frame of drawn beeswax and two frames

Host responses to interspecific brood parasitism: a by-product of adaptations to conspecific parasitism?

Science.gov (United States)

Samas, Peter; Hauber, Mark E; Cassey, Phillip; Grim, Tomas

2014-01-01

Why have birds evolved the ability to reject eggs? Typically, foreign egg discrimination is interpreted as evidence that interspecific brood parasitism (IP) has selected for the host's ability to recognize and eliminate foreign eggs. Fewer studies explore the alternative hypothesis that rejection of interspecific eggs is a by-product of host defenses, evolved against conspecific parasitism (CP). We performed a large scale study with replication across taxa (two congeneric Turdus thrushes), space (populations), time (breeding seasons), and treatments (three types of experimental eggs), using a consistent design of egg rejection experiments (n = 1057 nests; including controls), in areas with potential IP either present (Europe; native populations) or absent (New Zealand; introduced populations). These comparisons benefited from the known length of allopatry (one and a half centuries), with no gene flow between native and introduced populations, which is rarely available in host-parasite systems. Hosts rejected CP at unusually high rates for passerines (up to 60%). CP rejection rates were higher in populations with higher conspecific breeding densities and no risks of IP, supporting the CP hypothesis. IP rejection rates did not covary geographically with IP risk, contradicting the IP hypothesis. High egg rejection rates were maintained in the relatively long-term isolation from IP despite non-trivial rejection costs and errors. These egg rejection patterns, combined with recent findings that these thrushes are currently unsuitable hosts of the obligate parasitic common cuckoo (Cuculus canorus), are in agreement with the hypothesis that the rejection of IP is a by-product of fine-tuned egg discrimination evolved due to CP. Our study highlights the importance of considering both IP and CP simultaneously as potential drivers in the evolution of egg discrimination, and illustrates how populations introduced to novel ecological contexts can provide critical insights

Intrinsic colony conditions affect the provisioning and oviposition process in the stingless bee Melipona scutellaris.

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Pereira, R A; Morais, M M; Nascimento, F S; Bego, L R

2009-01-01

The cell provisioning and oviposition process (POP) is a unique characteristic of stingless bees (Meliponini), in which coordinated interactions between workers and queen regulate the filling of brood cells with larval resources and subsequent egg laying. Environmental conditions seem to regulate reproduction in stingless bees; however, little is known about how the amount of food affects quantitative sequences of the process. We examined intrinsic variables by comparing three colonies in distinct conditions (strong, intermediate and weak state). We predicted that some of these variables are correlated with temporal events of POP in Melipona scutellaris colonies. The results demonstrated that the strong colony had shorter periods of POP.

Study effects sublethal concentration of diazinon on testis, brain and heart of Rutilus frisii kutum (Kamensky, 1901 male brood stocks

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M Mohammad Nejad Shamoushaki

2011-11-01

Full Text Available In this study the effects of toxic pesticides, Diazinon (60% emulsion on the some tissues of (Rutilus frisii kutum, Kamensky, 1901 male brood stocks were studied. The test were studied under static water quality conditions at 15 °C ± 2 ºC in winter and spring 2009. The effective physical and chemical parameters of water were pH= 7-8.2, dh= 300 mg/L (caco3, DO= 7 ppm and T= 15 °C±2 ºC. LC50 96h pesticide Diazinon on the first 0.4 mg/L was determined and then fish were exposed by the toxin with 3 concentrations, MAC value, LC1, LC5, and a control with three replicates for 45 days. Pathology results showed toxin diazinon no effect on average weight and fish body length, the average weight of heart and brain but caueses decrease of gonad weigth and gonad index and also, cause complications of atrophy, fibrosis and necrosis in testis , vascular congestion, increased distance between the myocardium and fibrous string in heart and neuronal loss, vascular congestion and edema in the brain of kutum male brood stocks.

Immunological effects of CaEDTA injection: observations in two lead workers.

Science.gov (United States)

Sata, F; Araki, S; Sakai, T; Nakata, A; Yamashita, K; Morita, Y; Tanigawa, T; Miki, A

1997-12-01

To evaluate the effects of calcium disodium ethylenediamine tetraacetate (CaEDTA) injection on human immune system in relation to exposure to lead, we administered CaEDTA by intravenous injection for 1 hr three times (three consecutive days) a week to two male lead workers. They had been engaged in recycling lead for 31 and 22 years, aged 61 and 53 years (workers 1 and 2), respectively. Before the treatment of CaEDTA, their blood lead concentrations (PbB) were 81 and 68 micrograms/dl, respectively. The administration of CaEDTA had been carried out to worker 1 for 10 weeks and to worker 2 for 6 weeks. A significant decrease in PbB between before and after three-times CaEDTA injection was found in both workers. Significant increases in IgG, IgA, IgM, CD8+, and CD57+ cells were found in worker 1. A significant increase in IgD was found in worker 2. During the study period, IgG in worker 1 and CD4+ cells in worker 2 were gradually increasing. There was a significant negative correlation between IgG and PbB in worker 1. It is suggested that the immunological function such as antibody formation in lead workers might be improved by CaEDTA injection.

Differential induction of micronuclei in peripheral lymphocytes and exfoliated urothelial cells of workers exposed to 4,4'-methylenebis-(2-chloroaniline) (MOCA) and bitumen fumes.

Science.gov (United States)

Murray, E B; Edwards, J W

2005-01-01

Cytogenetic end-points used to estimate risk of genotoxic events in workers include the measurement of micronuclei (MN) in exfoliated cells, lymphocytes, and other tissues. Micronuclei are chromatin-containing bodies outside the cell nucleus resulting from contaminant-induced DNA damage. A review of 71 reports of human genotoxic responses to chemical or physical agents published between 1999 and 2001 revealed that 14% of such studies measured genotoxicity endpoints in specific target tissues relevant to the site of disease for the agent examined; 18% used endpoints in surrogate or non-target tissues but considered the relations between endpoints in surrogate and disease target tissues, and 68% measured genotoxicity endpoints in accessible tissues without reference to specific targets for disease. Methylenebis-(2-chloroaniline) (MOCA), used in polyurethane manufacture, is a suspected bladder carcinogen. Bitumen, used in road surfacing, contains skin and lung carcinogens. In this study, we aimed to compare genotoxicity in urothelial cells and in lymphocytes of workers exposed to these materials. Twelve men employed in polyurethane manufacture, twelve bitumen road layers, and eighteen hospital stores personnel (controls) were recruited and all provided blood and urine samples on the same day. Blood cultures were prepared using a cytochalasin B-block method. Exfoliated urothelial cells were collected from urine and stained for light microscopy. The number of MN in urothelial cells was higher in MOCA-exposed (14.27 +/- 0.56 MN/1000, 9.69 +/- 0.32 MN cells/1000) than in bitumen exposed workers (11.99 +/- 0.65 MN/1000, 8.66 +/- 0.46 MN cells/1000) or in control subjects (6.88 +/- 0.18 MN/1000, 5.17 +/- 0.11 MN cells/1000). Conversely, in lymphocytes, MN were higher in bitumen-exposed (16.24 +/- 0.63 MN/1000, 10.65 +/- 0.24 MN cells/1000) than in MOCA-exposed workers (13.25 +/- 0.48 MN/1000, 8.54 +/- 0.14 MN cells/1000) or in control subjects (9.24 +/- 0.29 MN/ 1000, 5

Founding weaver ant queens (Oecophylla longinoda) increase production and nanitic worker size when adopting non-nestmate pupae.

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Ouagoussounon, Issa; Offenberg, Joachim; Sinzogan, Antonio; Adandonon, Appolinaire; Kossou, Dansou; Vayssières, Jean-François

2015-01-01

Weaver ants (Oecophylla longinoda Latreille) are used commercially to control pest insects and for protein production. In this respect fast colony growth is desirable for managed colonies. Transplantation of non-nestmate pupae to incipient colonies has been shown to boost colony growth. Our objectives were to find the maximum number of pupae a founding queen can handle, and to measure the associated colony growth. Secondly, we tested if transplantation of pupae led to production of larger nanitic workers (defined as unusually small worker ants produced by founding queens in their first batch of offspring). Forty-five fertilized queens were divided into three treatments: 0 (control), 100 or 300 non-nestmate pupae transplanted to each colony. Pupae transplantation resulted in highly increased growth rates, as pupae were readily adopted by the queens and showed high proportions of surviving (mean = 76%). However, survival was significantly higher when 100 pupae were transplanted compared to transplantation of 300 pupae, indicating that queens were unable to handle 300 pupae adequately and that pupae require some amount of nursing. Nevertheless, within the 60-day experiment the transplantation of 300 pupae increased total colony size more than 10-fold whereas 100 pupae increased the size 5.6 fold, compared to control. This increase was due not only to the individuals added in the form of pupae but also to an increased per capita brood production by the resident queen, triggered by the adopted pupae. The size of hatching pupae produced by the resident queen also increased with the number of pupae transplanted, leading to larger nanitic workers in colonies adopting pupae. In conclusion, pupae transplantation may be used to produce larger colonies with larger worker ants and may thus reduce the time to produce weaver ant colonies for commercial purposes. This in turn may facilitate the implementation of the use of weaver ants.

Expression of Cyclin D1 protein and CCN DI with PNKP genes in peripheral blood mononuclear cells in clean-up worker of Chernobyl accident with different state of immune system

International Nuclear Information System (INIS)

Bazika, D.A.; Kubashko, A.V.; Yil'jenko, Yi.M.; Belyajev, O.A.; Pleskach, O.Ya.

2015-01-01

The investigate of Cyclin D1+cells levels changes, associated CCND1 and PNKP genes in peripheral blood mononuclear cells in cleanup workers of Chornobyl accident with different state of immune system in depends on the dose irradiation. Analyzed data of the nuclear controller of cell cycle- Cyclin D1 protein expression changes and related CCND1 and PNKP genes in peripheral blood mononuclear cells in cleanup workers Chornobyl accident with different status of immune system in remote period after exposure is represented. Reveled changes in expression of Cyclin D1+cells and regulation of related genes may point on possible radiation-associated firm molecular disturbances occurred during elimination of consequences of Chornobyl accident, that could be a potential basis for cell and humoral communicative links breach in immune system result ing in elevation of stochastic effects like oncopathology in cleanup workers of Chornobyl accident in remote peri od after exposure

Chromosome aberrations in workers of ignalina nuclear power plant

Energy Technology Data Exchange (ETDEWEB)

Griciene, B.; Januskeviciute, I.; Mierauskiene, J.; Slapsyte, G. [Vilnius Univ. (Lithuania)

2006-07-01

individual for the presence of chromosome aberrations. Chromosome aberration analysis revealed no differences between the two groups of radiation workers, or between the radiation workers and controls. The mean total chromosome aberration frequencies were: 1,32 {+-} 0,27 CA/100 cells (group A), 1,56{+-}0,39 CA/100 cells (group B), and 1,65{+-}0,15 CA/100 cells (group C). The average yield of dicentric chromosomes per 100 cells in A and B radiation groups was 0,10{+-}0.06 and 0,05{+-}0,04, respectively, and 0,08{+-}0,02 in controls. Thus, the results of the present study indicate no increase in chromosome aberration frequencies in I.N.P.P. workers exposed to doses close to permissible annual dose limits. The next blood sampling of I.N.P.P. workers will be performed in October 2005. The Lithuanian Bio ethics Committee approved the study. (authors)

Chromosome aberrations in workers of ignalina nuclear power plant

International Nuclear Information System (INIS)

Griciene, B.; Januskeviciute, I.; Mierauskiene, J.; Slapsyte, G.

2006-01-01

individual for the presence of chromosome aberrations. Chromosome aberration analysis revealed no differences between the two groups of radiation workers, or between the radiation workers and controls. The mean total chromosome aberration frequencies were: 1,32 ± 0,27 CA/100 cells (group A), 1,56±0,39 CA/100 cells (group B), and 1,65±0,15 CA/100 cells (group C). The average yield of dicentric chromosomes per 100 cells in A and B radiation groups was 0,10±0.06 and 0,05±0,04, respectively, and 0,08±0,02 in controls. Thus, the results of the present study indicate no increase in chromosome aberration frequencies in I.N.P.P. workers exposed to doses close to permissible annual dose limits. The next blood sampling of I.N.P.P. workers will be performed in October 2005. The Lithuanian Bio ethics Committee approved the study. (authors)

State of the immune protection system of brood carp (Cyprinus carpio Linnaeus, 1758 based on vitamin E and selenium levels in their diet

Directory of Open Access Journals (Sweden)

S. Yurchak

2017-12-01

Full Text Available Purpose: To assess the state of the immune system of brood carp, which were fed with a combined feed containing a liposomal preparation with vitamin E and organic compound of selenium microelement during pre-spawning period. Methodology: The study has been performed in three experimental ponds, in which carp females and males were placed after wintering. The first experimental group was fed with a diet supplemented with vitamin E at a concentration of 50 mg/mg of the feed and selenium – 0.3 mg/kg. The second experimental group received the supplement of vitamin E at a concentration of 100 mg.kg and selenium – 0.3 mg/kg. The control group received the mentioned combined feed without addition of the vitamin-mineral supplement. After termination of 30-day pre-spawning feeding with the combined feed supplemented with vitamin E and selenium, blood samples for biochemical tests were collected from fish of the control and both experimental groups. Findings. It was found that pre-spawning feeding of carp females and males with combined feeds supplemented with the above mentioned vitamin-mineral additive had a positive effect on the contents of T-, B-lymphocytes and their subpopulations in fish blood. Originality. The effect of the liposomal preparation with vitamin E and microelement Se fed to brood carp during the pre-spawning period on the contents of T-, B-lymphocytes and their subpopulations in fish peripheral blood was studied for the first time. Practical value. The results of the study can be used in fish breeding centers and full-system fish farms for balanced feeding of brood fish.

Bacterial Respiration and Growth Rates Affect the Feeding Preferences, Brood Size and Lifespan of Caenorhabditis elegans

Science.gov (United States)

Yu, Li; Yan, Xiaomei; Ye, Chenglong; Zhao, Haiyan; Chen, Xiaoyun; Hu, Feng; Li, Huixin

2015-01-01

Bacteria serve as live food and nutrients for bacterial-feeding nematodes (BFNs) in soils, and influence nematodes behavior and physiology through their metabolism. Five bacterial taxa (Bacillus amyloliquefaciens JX1, Variovorax sp. JX14, Bacillus megaterium JX15, Pseudomonas fluorescens Y1 and Escherichia coli OP50) and the typical BFN Caenorhabditis elegans were selected to study the effects of bacterial respiration and growth rates on the feeding preferences, brood size and lifespan of nematodes. P. fluorescens Y1 and E. coli OP50 were found to be more active, with high respiration and rapid growth, whereas B. amyloliquefaciens JX1 and B. megaterium JX15 were inactive. The nematode C. elegans preferred active P. fluorescens Y1 and E. coli OP50 obviously. Furthermore, worms that fed on these two active bacteria produced more offspring but had shorter lifespan, while inactive and less preferred bacteria had increased nematodes lifespan and decreased the brood size. Based on these results, we propose that the bacterial activity may influence the behavior and life traits of C. elegans in the following ways: (1) active bacteria reproduce rapidly and emit high levels of CO2 attracting C. elegans; (2) these active bacteria use more resources in the nematodes’ gut to sustain their survival and reproduction, thereby reducing the worm's lifespan; (3) inactive bacteria may provide less food for worms than active bacteria, thus increasing nematodes lifespan but decreasing their fertility. Nematodes generally require a balance between their preferred foods and beneficial foods, only preferred food may not be beneficial for nematodes. PMID:26222828

Reproductive ecology and early life history traits of the brooding coral, Porites astreoides, from shallow to mesophotic zones

Science.gov (United States)

Goodbody-Gringley, Gretchen; Wong, Kevin H.; Becker, Danielle M.; Glennon, Keegan; de Putron, Samantha J.

2018-06-01

Early life history traits of brooding corals are often affected by the environmental conditions experienced by parental colonies. Such parental effects can impact offspring survival, which influences the overall success of a population as well as resilience to environmental challenges. This study examines the reproductive ecology and early life history traits of the brooding coral Porites astreoides across a depth gradient in Bermuda. Fecundity, larval size, larval Symbiodinium density, and settlement success, as well as post-metamorphic juvenile survival, growth, and Symbiodinium density were compared across three reef sites representing an inshore patch reef (2-5 m), an offshore rim reef (8-10 m), and an upper-mesophotic reef (30-33 m). Although fecundity did not differ across sites, larvae produced by colonies on the patch reef site were smaller, had lower Symbiodinium densities, and had lower rates of settlement and juvenile survival compared to larvae from colonies on the rim and upper-mesophotic reef sites. Larvae produced by colonies from the rim and upper-mesophotic sites did not differ in size or Symbiodinium densities; however, rates of settlement, growth, and survival were higher for larvae from the upper-mesophotic site compared to those from the rim reef site. These results indicate that offspring quality and success vary among sites with differing environmental conditions and may imply higher recruitment potential and resilience for upper-mesophotic corals.

The sight of an adult brood parasite near the nest is an insufficient cue for a honeyguide host to reject foreign eggs

Science.gov (United States)

Tong, Wenfei; Horrocks, Nicholas P C; Spottiswoode, Claire N

2015-01-01

Hosts of brood-parasitic birds typically evolve anti-parasitism defences, including mobbing of parasitic intruders at the nest and the ability to recognize and reject foreign eggs from their clutches. The Greater Honeyguide Indicator indicator is a virulent brood parasite that punctures host eggs and kills host young, and accordingly, a common host, the Little Bee-eater Merops pusillus frequently rejects entire clutches that have been parasitized. We predicted that given the high costs of accidentally rejecting an entire clutch, and that the experimental addition of a foreign egg is insufficient to induce this defence, Bee-eaters require the sight of an adult parasite near the nest as an additional cue for parasitism before they reject a clutch. We found that many Little Bee-eater parents mobbed Greater Honeyguide dummies while ignoring barbet control dummies, showing that they recognized them as a threat. Surprisingly, however, neither a dummy Honeyguide nor the presence of a foreign egg, either separately or in combination, was sufficient to stimulate egg rejection. PMID:26300559

Tucannon River Spring Chinook Salmon Captive Brood Program, FY 2000 Annual Report.

Energy Technology Data Exchange (ETDEWEB)

Bumgarner, Joseph D.; Gallinat, Michael P.

2001-06-01

This report summarizes the objectives, tasks, and accomplishments of the Tucannon River spring chinook captive brood program from program inception (1997) through April 2001. The WDFW initiated a captive broodstock program in 1997. The overall goal of the Tucannon River captive broodstock program is for the short-term, and eventually long-term, rebuilding of the Tucannon River spring chinook salmon run, with the hope that natural production will eventually sustain itself. The project goal is to rear captive salmon to adults, spawn them, rear their progeny, and release approximately 150,000 smolts annually into the Tucannon River between 2003-2007. These smolt releases, in combination with the current hatchery supplementation program (132,000 smolts), and wild production, is expected to produce 600-700 returning adult spring chinook to the Tucannon River each year from 2005-2010. The Master Plan, Environmental Assessment, and most facility modifications at LFH were completed for the Tucannon River spring chinook captive broodstock program during FY2000 and FY2001. DNA samples collected since 1997 have been sent to the WDFW genetics lab in Olympia for baseline DNA analysis. Results from the genetic analysis are not available at this time. The captive broodstock program is planned to collect fish from five (1997-2001) brood years (BY). The captive broodstock program was initiated with 1997 BY juveniles, and the 2000 BY fish have been selected. As of April 30, 2001, WDFW has 172 BY 1997, 262 BY 1998, 407 BY 1999, and approximately 1,190 BY 2000 fish on hand at LFH. Twelve of 13 mature 97 BY females were spawned in 2000. Total eggtake was 14,813. Mean fecundity was 1,298 eggs/female based on 11 fully spawned females. Egg survival to eye-up was 47.3%. This low survival was expected for three year old captive broodstock females. As of April 30, 2001, WDFW has 4,211 captive broodstock progeny on hand. These fish will be tagged with blank wire tag without fin clips and

Dermal exposure to jet fuel JP-8 significantly contributes to the production of urinary naphthols in fuel-cell maintenance workers.

Science.gov (United States)

Chao, Yi-Chun E; Kupper, Lawrence L; Serdar, Berrin; Egeghy, Peter P; Rappaport, Stephen M; Nylander-French, Leena A

2006-02-01

Jet propulsion fuel 8 (JP-8) is the major jet fuel used worldwide and has been recognized as a major source of chemical exposure, both inhalation and dermal, for fuel-cell maintenance workers. We investigated the contributions of dermal and inhalation exposure to JP-8 to the total body dose of U.S. Air Force fuel-cell maintenance workers using naphthalene as a surrogate for JP-8 exposure. Dermal, breathing zone, and exhaled breath measurements of naphthalene were obtained using tape-strip sampling, passive monitoring, and glass bulbs, respectively. Levels of urinary 1- and 2-naphthols were determined in urine samples and used as biomarkers of JP-8 exposure. Multiple linear regression analyses were conducted to investigate the relative contributions of dermal and inhalation exposure to JP-8, and demographic and work-related covariates, to the levels of urinary naphthols. Our results show that both inhalation exposure and smoking significantly contributed to urinary 1-naphthol levels. The contribution of dermal exposure was significantly associated with levels of urinary 2-naphthol but not with urinary 1-naphthol among fuel-cell maintenance workers who wore supplied-air respirators. We conclude that dermal exposure to JP-8 significantly contributes to the systemic dose and affects the levels of urinary naphthalene metabolites. Future work on dermal xenobiotic metabolism and toxicokinetic studies are warranted in order to gain additional knowledge on naphthalene metabolism in the skin and the contribution to systemic exposure.

Measurement of DNA repair deficiency in workers exposed to benzene

International Nuclear Information System (INIS)

Hallberg, L.M.; Au, W.W.; El Zein, R.; Grossman, L.

1996-01-01

We hypothesize that chronic exposure to environmental toxicants can induce genetic damage causing DNA repair deficiencies and leading to the postulated mutator phenotype of carcinogenesis. To test our hypothesis, a host cell reactivation (HCR) assay was used in which pCMVcat plasmids were damaged with UV light (175, 350 J/m 2 UV light), inactivating the chloramphenicol acetyltransferase reporter gene, and then transfected into lymphocytes. Transfected lymphocytes were therefore challenged to repair the damaged plasmids, reactivating the reporter gene. Xeroderma pigmentosum (XP) and Gaucher cell lines were used as positive and negative controls for the HCR assay. The Gaucher cell line repaired normally but XP cell lines demonstrated lower repair activity. Additionally, the repair activity of the XP heterozygous cell line showed intermediate repair compared to the homozygous XP and Gaucher cells. We used HCR to measure the effects of benzene exposure on 12 exposed and 8 nonexposed workers from a local benzene plant. Plasmids 175 J/m 2 and 350 J/m 2 were repaired with a mean frequency of 66% and 58%, respectively, in control workers compared to 71% and 62% in exposed workers. Conversely, more of the exposed workers were grouped into the reduced repair category than controls. These differences in repair capacity between exposed and control workers were, however, not statistically significant. The lack of significant differences between the exposed and control groups may be due to extremely low exposure to benzene (<0.3 ppm), small population size, or a lack of benzene genotoxicity at these concentrations. These results are consistent with a parallel hprt gene mutation assay. 26 refs., 4 figs., 2 tabs

Linking Genes and Brain Development of Honeybee Workers: A Whole-Transcriptome Approach.

Directory of Open Access Journals (Sweden)

Christina Vleurinck

Full Text Available Honeybees live in complex societies whose capabilities far exceed those of the sum of their single members. This social synergism is achieved mainly by the worker bees, which form a female caste. The worker bees display diverse collaborative behaviors and engage in different behavioral tasks, which are controlled by the central nervous system (CNS. The development of the worker brain is determined by the female sex and the worker caste determination signal. Here, we report on genes that are controlled by sex or by caste during differentiation of the worker's pupal brain. We sequenced and compared transcriptomes from the pupal brains of honeybee workers, queens and drones. We detected 333 genes that are differently expressed and 519 genes that are differentially spliced between the sexes, and 1760 genes that are differentially expressed and 692 genes that are differentially spliced between castes. We further found that 403 genes are differentially regulated by both the sex and caste signals, providing evidence of the integration of both signals through differential gene regulation. In this gene set, we found that the molecular processes of restructuring the cell shape and cell-to-cell signaling are overrepresented. Our approach identified candidate genes that may be involved in brain differentiation that ensures the various social worker behaviors.

Immune functions of the garment workers.

Science.gov (United States)

Sultana, R; Ferdous, K J; Hossain, M; Zahid, M S H; Islam, L N

2012-10-01

Occupational exposure to cotton dust, fibers, metal fumes and different chemicals used in the aparrel manufacturing industries cause a wide range of physical and psychological health problems in the garment workers that may also affect their immune function. To assess the immune system function in garment workers. A total of 45 workers of a garment factory, and 41 control subjects, not exposed to the garment working environment were enrolled in this study. In the study subjects, the complement system function was assessed as bactericidal activity on Escherichia coli DH5α cells using the standard plate count method. Serum complement components C3 and C4 were measured by immunoprecipitation, and IgG was measured by immunonephelometry. The bactericidal activity of serum complement in the garment workers (range: 93.5%-99.9%) was significantly (pgarment workers, the mean levels of complement C3, and C4 were 1.75 and 0.26 g/L, respectively that were close to those of the controls. The mean IgG level in the garment workers was 13.5 g/L that was significantly (pgarment factory may affect the immune system.

Genetic diversity of a Daugava basin brown trout (Salmo trutta brood stock

Directory of Open Access Journals (Sweden)

Schmidt Thomas

2017-01-01

Full Text Available Genetics play an increasingly important role in the conservation of threatened fish populations. We have examined twelve microsatellite markers to determine the genetic diversity of a brood stock of brown trout from the Latvian Daugava river basin, used in a local supportive breeding program and compared diversity values to other Baltic populations. Allelic data was further inspected for indications of increased inbreeding. Additionally, we have analyzed the mitochondrial control region to classify the population within a broader phylogenetic framework. We found that the genetic diversity was comparatively low, but there was no strong evidence of high inbreeding. A newly detected mitochondrial haplotype indicates unnoticed genetic diversity of “Atlantic lineage” brown trout in the Daugava basin region. Our study provides first genetic details on resident brown trout from the Baltic Daugava river basin to improve the regional conservation management of this valuable genetic resource and contributes phylogeographically useful information.

Asteraceae Pollen Provisions Protect Osmia Mason Bees (Hymenoptera: Megachilidae) from Brood Parasitism.

Science.gov (United States)

Spear, Dakota M; Silverman, Sarah; Forrest, Jessica R K

2016-06-01

Many specialist herbivores eat foods that are apparently low quality. The compensatory benefits of a poor diet may include protection from natural enemies. Several bee lineages specialize on pollen of the plant family Asteraceae, which is known to be a poor-quality food. Here we tested the hypothesis that specialization on Asteraceae pollen protects bees from parasitism. We compared rates of brood parasitism by Sapyga wasps on Asteraceae-specialist, Fabeae-specialist, and other species of Osmia bees in the field over several years and sites and found that Asteraceae-specialist species were parasitized significantly less frequently than other species. We then tested the effect of Asteraceae pollen on parasites by raising Sapyga larvae on three pollen mixtures: Asteraceae, Fabeae, and generalist (a mix of primarily non-Asteraceae pollens). Survival of parasite larvae was significantly reduced on Asteraceae provisions. Our results suggest that specialization on low-quality pollen may evolve because it helps protect bees from natural enemies.

Origins, evolution, and diversification of cleptoparasitic lineages in long-tongued bees.

Science.gov (United States)

Litman, Jessica R; Praz, Christophe J; Danforth, Bryan N; Griswold, Terry L; Cardinal, Sophie

2013-10-01

The evolution of parasitic behavior may catalyze the exploitation of new ecological niches yet also binds the fate of a parasite to that of its host. It is thus not clear whether evolutionary transitions from free-living organism to parasite lead to increased or decreased rates of diversification. We explore the evolution of brood parasitism in long-tongued bees and find decreased rates of diversification in eight of 10 brood parasitic clades. We propose a pathway for the evolution of brood parasitic strategy and find that a strategy in which a closed host nest cell is parasitized and the host offspring is killed by the adult parasite represents an obligate first step in the appearance of a brood parasitic lineage; this ultimately evolves into a strategy in which an open host cell is parasitized and the host offspring is killed by a specialized larval instar. The transition to parasitizing open nest cells expanded the range of potential hosts for brood parasitic bees and played a fundamental role in the patterns of diversification seen in brood parasitic clades. We address the prevalence of brood parasitic lineages in certain families of bees and examine the evolution of brood parasitism in other groups of organisms. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.

Patient housing barriers to hematopoietic cell transplantation: results from a mixed-methods study of transplant center social workers.

Science.gov (United States)

Preussler, Jaime M; Mau, Lih-Wen; Majhail, Navneet S; Bevans, Margaret; Clancy, Emilie; Messner, Carolyn; Parran, Leslie; Pederson, Kate A; Ferguson, Stacy Stickney; Walters, Kent; Murphy, Elizabeth A; Denzen, Ellen M

2016-03-01

Hematopoietic cell transplantation (HCT) is performed in select centers in the United States (U.S.), and patients are often required to temporarily relocate to receive care. The purpose of this study was to identify housing barriers impacting access to HCT and potential solutions. A mixed-methods primary study of HCT social workers was conducted to learn about patient housing challenges and solutions in place that help address those barriers. Three telephone focus groups were conducted with adult and pediatric transplant social workers (n = 15). Focus group results informed the design of a national survey. The online survey was e-mailed to a primary social worker contact at 133 adult and pediatric transplant centers in the U.S. Transplant centers were classified based on the patient population cared for by the social worker. The survey response rate was 49%. Among adult programs (n = 45), 93% of centers had patients that had to relocate closer to the transplant center to proceed with HCT. The most common type of housing option offered was discounted hotel rates. Among pediatric programs (n = 20), 90% of centers had patients that had to relocate closer to the transplant center to proceed with HCT. Ronald McDonald House was the most common option available. This study is the first to explore housing challenges faced by patients undergoing HCT in the U.S. from the perspective of social workers and to highlight solutions that centers use. Transplant centers will benefit from this knowledge by learning about options for addressing housing barriers for their patients.

Neonicotinoid insecticides in pollen, honey and adult bees in colonies of the European honey bee (Apis mellifera L.) in Egypt.

Science.gov (United States)

Codling, Garry; Naggar, Yahya Al; Giesy, John P; Robertson, Albert J

2018-03-01

Honeybee losses have been attributed to multiple stressors and factors including the neonicotinoid insecticides (NIs). Much of the study of hive contamination has been focused upon temperate regions such as Europe, Canada and the United States. This study looks for the first time at honey, pollen and bees collected from across the Nile Delta in Egypt in both the spring and summer planting season of 2013. There is limited information upon the frequency of use of NIs in Egypt but the ratio of positive identification and concentrations of NIs are comparable to other regions. Metabolites of NIs were also monitored but given the low detection frequency, no link between matrices was possible in the study. Using a simple hazard assessment based upon published LD 50 values for individual neonicotinoids upon the foraging and brood workers it was found that there was a potential risk to brood workers if the lowest reported LD 50 was compared to the sum of the maximum NI concentrations. For non-lethal exposure there was significant risk at the worst case to brood bees but actual exposure effects are dependant upon the genetics and conditions of the Egyptian honeybee subspecies that remain to be determined.

Alternative reproductive tactics in snail shell-brooding cichlids diverge in energy reserve allocation.

Science.gov (United States)

von Kuerthy, Corinna; Tschirren, Linda; Taborsky, Michael

2015-05-01

Life history theory predicts that the amount of resources allocated to reproduction should maximize an individual's lifetime reproductive success. So far, resource allocation in reproduction has been studied mainly in females. Intraspecific variation of endogenous energy storage and utilization patterns of males has received little attention, although these patterns may vary greatly between individuals pursuing alternative reproductive tactics (ARTs). ARTs are characterized by systematic variation of behavioral, physiological, and often morphological traits among same-sex conspecifics. Some individuals may rely on previously accumulated reserves, because of limited foraging opportunities during reproduction. Others may be able to continue foraging during reproduction, thus relying on reserves to a lesser extent. We therefore predicted that, if male tactics involve such divergent limitations and trade-offs within a species, ARTs should correspondingly differ in energy reserve allocation and utilization. To test this prediction, we studied short-term and long-term reserve storage patterns of males in the shell-brooding cichlid Lamprologus callipterus. In this species, bourgeois males investing in territory defense, courtship, and guarding of broods coexist with two distinct parasitic male tactics: (1) opportunistic sneaker males attempting to fertilize eggs by releasing sperm into the shell opening when a female is spawning; and (2) specialized dwarf males attempting to enter the shell past the spawning female to fertilize eggs from inside the shell. Sneaker males differed from other male types by showing the highest amount of accumulated short-term and long-term fat stores, apparently anticipating their upcoming adoption of the nest male status. In contrast, nest males depleted previously accumulated energy reserves with increasing nest holding period, as they invest heavily into costly reproductive behaviors while not taking up any food. This conforms to a capital

Tucannon River spring chinook salmon captive brood program, FY 2000 annual report; ANNUAL

International Nuclear Information System (INIS)

Bumgarner, Joseph D.; Gallinat, Michael P.

2001-01-01

This report summarizes the objectives, tasks, and accomplishments of the Tucannon River spring chinook captive brood program from program inception (1997) through April 2001. The WDFW initiated a captive broodstock program in 1997. The overall goal of the Tucannon River captive broodstock program is for the short-term, and eventually long-term, rebuilding of the Tucannon River spring chinook salmon run, with the hope that natural production will eventually sustain itself. The project goal is to rear captive salmon to adults, spawn them, rear their progeny, and release approximately 150,000 smolts annually into the Tucannon River between 2003-2007. These smolt releases, in combination with the current hatchery supplementation program (132,000 smolts), and wild production, is expected to produce 600-700 returning adult spring chinook to the Tucannon River each year from 2005-2010. The Master Plan, Environmental Assessment, and most facility modifications at LFH were completed for the Tucannon River spring chinook captive broodstock program during FY2000 and FY2001. DNA samples collected since 1997 have been sent to the WDFW genetics lab in Olympia for baseline DNA analysis. Results from the genetic analysis are not available at this time. The captive broodstock program is planned to collect fish from five (1997-2001) brood years (BY). The captive broodstock program was initiated with 1997 BY juveniles, and the 2000 BY fish have been selected. As of April 30, 2001, WDFW has 172 BY 1997, 262 BY 1998, 407 BY 1999, and approximately 1,190 BY 2000 fish on hand at LFH. Twelve of 13 mature 97 BY females were spawned in 2000. Total eggtake was 14,813. Mean fecundity was 1,298 eggs/female based on 11 fully spawned females. Egg survival to eye-up was 47.3%. This low survival was expected for three year old captive broodstock females. As of April 30, 2001, WDFW has 4,211 captive broodstock progeny on hand. These fish will be tagged with blank wire tag without fin clips and

Cytogenetic monitoring of hospital workers exposed to low-level ionizing radiation

International Nuclear Information System (INIS)

Bigatti, P.; Lamberti, L.; Ardito, G.; Armellino, F.

1988-01-01

In the present study the cytogenetic effects in hospital workers exposed to low-level radiation were evaluated. Samples of peripheral blood were collected from 63 subjects working in radiodiagnostics and from 30 subjects, working in the same hospitals, who were used as controls. A higher number of cells with chromosome-type aberrations (CA) was observed in the exposed workers vs. the controls and the difference was statistically significant (p<0.05). No correlation was, on the contrary, found between CA and years of exposure. A significant difference was observed in the incidence of cells with CA between smokers and non-smokers, but in the control group only. In contrast, in the workers exposed to ionizing radiation, the frequency of cells with CA was very similar in smokers and non-smokers. 13 refs.; 4 tabs

The effects of selection on low mortality and brooding by a mother hen on open-field response, feather pecking and cannibalism in laying hens

NARCIS (Netherlands)

Rodenburg, T.B.; Uitdehaag, K.A.; Ellen, E.D.; Komen, J.

2009-01-01

The aim of the present study was to investigate the effects of selection on low mortality in combination with brooding by a mother hen on open-field response at 5-6 weeks of age and on plumage and body condition at 42 weeks of age. Birds in the experiment were either selected for low mortality in

Evaluation of 1991--1992 brood overwinter-reared coho released from net pens in Youngs Bay, Oregon. Final completion report

International Nuclear Information System (INIS)

Hirose, P.S.

1997-01-01

Funding from Bonneville Power Administration was provided to the Oregon Department of Fish and Wildlife and the Clatsop County Economic Development Council's Fisheries Project to identify and develop terminal fishing opportunities. The 1991 and 1992 brood fingerling coho from Oregon Department of Fish and Wildlife hatcheries were successfully reared during the winter period to smolt stage in Youngs Bay utilizing floating net pens. Based on coded-wire-tag recoveries during 1991--93 from 2-week net-pen acclimation releases, total accountability of coho adults averaged 40,540 fish, with the Youngs Bay commercial harvest accounting for 39%. With reduced ocean harvest impacts during 1994 and 1995, 92% of 51,640 coho in 1994 and 68% of 23,599 coho in 1995 (based on coded-wire-tag recoveries) were accounted for in the Youngs Bay commercial fishery for combined 2-week and overwinter acclimation net-pen releases. Overwinter net-pen acclimation coho accounted for 35,063 and 15,775 coho adults in 1994 and 1995 with 93% and 68% accountable in the Youngs Bay commercial harvest. Based on coded-wire-tag recoveries, less than 1% of the adults resulting from releases at Youngs Bay net pens strayed to hatcheries, while none were recovered on spawning ground surveys during 1991--95. The highest survival rates were observed for 1991 and 1992 brood overwinter coho released in early May. Time of release, not rearing strategy, appears to be the determining factor affecting survival in Youngs Bay

Bio-monitoring for the genotoxic assessment in road construction workers as determined by the buccal micronucleus cytome assay.

Science.gov (United States)

Çelik, Ayla; Yildirim, Seda; Ekinci, Seda Yaprak; Taşdelen, Bahar

2013-06-01

Buccal micronucleus cytome (BMCyt) assay monitors genetic damage, cell proliferation and cell death in humans exposed to occupational and environmental agents. BMCyt is used as an indicator of genotoxic exposure, since it is associated with chromosomal instability. There is little research on the occupational exposure among road construction workers for genotoxicity testing. In the present study, we evaluated MN frequencies and other nuclear changes, karyorrhexis (KR), karyolysis (KL), broken egg (BE), binucleate (BN), condensed chromatin cell (CCC), and picnotic cell (PC) in buccal mucosa cells of 40 road construction workers (twenty smokers and twenty non-smokers) and 40 control groups consisting of healthy persons (twenty smokers and twenty non-smokers). Microscopic observation was performed of 2000 cells per individual in both road construction workers and control group. In control and worker groups, for each person repair index (RI) was calculated via formula KR+L/BE+MN. The results showed a statistically significant increase in the frequency of MN in buccal epithelial cells of exposed group compared with control group (proad construction workers, RI is lower than the control group. There is a significant difference between workers and control group (proad paving operations are absorbed by workers and that asphalt fume exposure is able to significantly induce cytogenetic damage in buccal mucosa cells of workers after controlling some possible confounding factors, such as age, sex and smoking habits. In addition to determination of nuclear changes and the micronucleus, the determination of RI value presents a new approach to genotoxic bio-monitoring assessment studies of occupationally exposed population. Copyright © 2013 Elsevier Inc. All rights reserved.

Rapid parallel evolution overcomes global honey bee parasite.

Science.gov (United States)

Oddie, Melissa; Büchler, Ralph; Dahle, Bjørn; Kovacic, Marin; Le Conte, Yves; Locke, Barbara; de Miranda, Joachim R; Mondet, Fanny; Neumann, Peter

2018-05-16

In eusocial insect colonies nestmates cooperate to combat parasites, a trait called social immunity. However, social immunity failed for Western honey bees (Apis mellifera) when the ectoparasitic mite Varroa destructor switched hosts from Eastern honey bees (Apis cerana). This mite has since become the most severe threat to A. mellifera world-wide. Despite this, some isolated A. mellifera populations are known to survive infestations by means of natural selection, largely by supressing mite reproduction, but the underlying mechanisms of this are poorly understood. Here, we show that a cost-effective social immunity mechanism has evolved rapidly and independently in four naturally V. destructor-surviving A. mellifera populations. Worker bees of all four 'surviving' populations uncapped/recapped worker brood cells more frequently and targeted mite-infested cells more effectively than workers in local susceptible colonies. Direct experiments confirmed the ability of uncapping/recapping to reduce mite reproductive success without sacrificing nestmates. Our results provide striking evidence that honey bees can overcome exotic parasites with simple qualitative and quantitative adaptive shifts in behaviour. Due to rapid, parallel evolution in four host populations this appears to be a key mechanism explaining survival of mite infested colonies.

The Activity of Carbohydrate-Degrading Enzymes in the Development of Brood and Newly Emerged workers and Drones of the Carniolan Honeybee, Apis mellifera carnica

OpenAIRE

Żółtowska, Krystyna; Lipiński, Zbigniew; Łopieńska-Biernat, Elżbieta; Farjan, Marek; Dmitryjuk, Małgorzata

2012-01-01

The activity of glycogen Phosphorylase and carbohydrate hydrolyzing enzymes α-amylase, glucoamylase, trehalase, and sucrase was studied in the development of the Carniolan honey bee, Apis mellifera carnica Pollman (Hymenoptera: Apidae), from newly hatched larva to freshly emerged imago of worker and drone. Phosphorolytic degradation of glycogen was significantly stronger than hydrolytic degradation in all developmental stages. Developmental profiles of hydrolase activity were similar in both ...

EFFECT OF A LIPOSOMAL PREPARATION OF VITAMINS A, E AND ORGANIC COMPOUNDS OF TRACE ELEMENTS OF Zn, Se, I ON THE PHYSIOLOGICAL STATE OF BROOD CARP (CYPRINUS CARPIO DURING PRESPAWNING PERIOD

Directory of Open Access Journals (Sweden)

Yu. Zabytivskyi

2014-12-01

Full Text Available Purpose. Evaluation of the physiological and biochemical status of the organism of brood carps, which during spawning period were fed with a liposomal preparation with a vitamins A, E and organic compounds of microelements of Zn, Se, І. Methodology. During a 30-day prespawning period, the experimental group of brood carp received a complex liposomal preparation, which included: vitamin A – 5000 IU/kg, vitamin E – 10 mg/kg, Zn – 15 mg/kg (zinc glutamate, Se – 0.3 mg/kg (commercial preparation «Sel-Plex», І – 5 mg/kg (experimental preparation «Lipoiodine» and sunflower phospholipid – 100 mg/kg. The liposomal emulsion prepared in an ultrasonic disperser at a frequency 35 Hz. Determinations of activity of ALT, AST, ALP, Chol, Ck, and to content of cholesterol, urea, creatinine, uric acid, total protein, albumin and glucose in serum were carried out in the biochemical analyzer Cobas Mira with the use of test-systems. Findings. We found a positive effect of the supplement on the integrity of cellular membranes of hepatopancreas and kidney that was evident as a reduction in serum ALT activity. A possible increase in ALP activity by 1.9 time indicates on an increase in phosphoric acid metabolism intensity that was related to the processes of phosphorus accumulation in fish eggs. The liposomal supplement has an effect on the reduction of uric acid content in blood by 16 times compared to the control group that indicated on the intensification of protein metabolism. An accumulation of the necessary quantity of amino acids is one of the drivers of the preparation of egg for embryogenesis. Originality. First demonstration of the effect of the liposomal preparation with vitamins A, E and organic forms of microelements of Zn, Se, І, which was fed to brood carp during prespawning period on the physiological and biochemical characteristics of serum. Practical value. The results of the work can be used for the development of prespawning brood

Contribution of honeybee drones of different age to colonial thermoregulation.

Science.gov (United States)

Kovac, Helmut; Stabentheiner, Anton; Brodschneider, Robert

2009-01-01

In addition to honeybee workers, drones also contribute to colonial thermoregulation. We show the drones' contribution to thermoregulation at 5 different experimental temperatures ranging from 15-34 °C. The frequency and the degree of endothermy depended on the drones' local ambient temperature and age. Location on brood or non-brood areas had no influence. The frequency of endothermic drones and the intensity of endothermy increased with decreasing temperature. 30% of drones of 8 days and older heated their thorax by more than 1 °C above the abdomen. The youngest drones (0-2 days) did not exceed this level of endothermy. Though young drones were less often engaged in active heat production, their contribution to brood warming was not insignificant because their abundance on the brood nest was 3.5 times higher than that of the oldest drones (≥13 days). Results suggest that the stimulus for the drones' increased frequency of heating at low experimental temperatures was their low local ambient air and/or comb temperature.

Contribution of honeybee drones of different age to colonial thermoregulation*

Science.gov (United States)

Kovac, Helmut; Stabentheiner, Anton; Brodschneider, Robert

2011-01-01

In addition to honeybee workers, drones also contribute to colonial thermoregulation. We show the drones’ contribution to thermoregulation at 5 different experimental temperatures ranging from 15–34 °C. The frequency and the degree of endothermy depended on the drones’ local ambient temperature and age. Location on brood or non-brood areas had no influence. The frequency of endothermic drones and the intensity of endothermy increased with decreasing temperature. 30% of drones of 8 days and older heated their thorax by more than 1 °C above the abdomen. The youngest drones (0–2 days) did not exceed this level of endothermy. Though young drones were less often engaged in active heat production, their contribution to brood warming was not insignificant because their abundance on the brood nest was 3.5 times higher than that of the oldest drones (≥13 days). Results suggest that the stimulus for the drones’ increased frequency of heating at low experimental temperatures was their low local ambient air and/or comb temperature. PMID:22140282

Estimates of covariance components for hygienic behavior in Africanized honeybees (Apis mellifera

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Fabiana Martins Costa-Maia

2011-09-01

Full Text Available Genetic and phenotypic parameters considering the genetic effect on hygienic behavior of queen and workers from 40 Africanized honeybees colonies were estimated separately. Maternal origin of queens was controlled whereas the paternal was unknown, and different groups of workers were considered in three seasons, October 2006, April 2007 and August 2007, but with the same queen. Colonies were 21 honey producers and 19 royal jelly producers. After the method of freezing capped brood, hygienic behavior was determined by the ratio between the number of dead capped brood removed at 24, 48 and 72 hours and the total number of capped brood at zero hour. Data was submitted to single and three traits analyses using Bayesian inference. Estimates of direct heritability at 24, 48 and 72 hours (0.10, 0.11 and 0.11 were identical to the motherly ones. Estimates by three trait analysis of direct heritability were 0.28, 0.15, 0.24, and of maternal heritability were 0.23, 0.29, 0.27, at 24, 48 and 72 hours, respectively. Correlations between maternal and genetic effects were 0.12, 0.09 and - 0.08 at, 24, 48 and 72 hours, respectively. Correlation between 24 and 48 hours was 0.49; between 24 and 72 hours, 0.40; and between 48 and 72 hours, 0.47. Moderate genetic correlations with the number of capped brood removed until 48 and 72 hours indicate that after the selection of a few generations, these traits can become an efficient criterion for selection in 24 hours.

Cytogenetic studies in workers with chronic occupational radiation exposure

International Nuclear Information System (INIS)

Grynszpan, D.

1989-01-01

The technique of chromosomal aberration detection on peripheral lymphocytes blood samples from monazite industry workers was used to study the cytogenetic effect of low chronic radiation doses. Cells from 51 workers and 21 controls were analysed. Cytogenetic data from individuals from different working areas were statistically compared among themselves and with the control group. The possible correlations between chromosomal aberration frequencies and cumulative external dose and working time were investigated. The influence of smoking was also tested. The link to the wives spontaneous abortions was analysed. Our results indicate possible biological effects on this sample of workers. (author)

Varroa destructor mite mortality rate according to the amount of worker broods in africanized honey bee (Apis mellifera L. colonies = Taxa de mortalidade do ácaro Varroa destructor de acordo com a quantidade de crias em colônias de abelhas africanizadas (Apis mellifera L.

Directory of Open Access Journals (Sweden)

Geraldo Moretto

2007-07-01

Full Text Available The Varroa destructor mite has caused the death of hundreds of thousands of Apis mellifera colonies in several countries worldwide. However, the effects determined by the Varroa mite change according to the A. mellifera subspecies. In Africanized bee colonies from South and Central America, the parasite causes little damage, as the infestation levels are relatively stable and low, thus treatments against the pest are not required. Among several factors, the grooming behavior of Africanized worker bees plays an important role in the maintenance of the low infestation levels. This study determined the daily rate of live and dead mites found at the bottom of the hive in five Africanized honey bee colonies. During fifteen days of observations, a significant increase was verified in the number of live and dead mites at the bottom of the hive as the amount of worker broods from each honey bee colony decreased. This suggests a more intense grooming activity as the Varroa concentration in the adult honey bee population increases.O ácaro Varroa destructor tem causado a mortalidade de centenas de milhares de colônias de abelhas Apis mellifera em várias partes do mundo. Os efeitos determinados pelo ácaro Varroa variam com a subespécie de Apis mellifera. Nas Américas do Sul e Central, o parasita causa poucos danos às colônias de abelhas africanizadas, a taxa de infestação é estável e baixa, não sendo necessário o tratamento químico contra a praga. Entre vários fatores que são responsáveis pela tolerância das abelhas africanizadas a esse parasita, o comportamento de grooming executado pelas operárias deve exercer importante papel na manutenção dos baixos níveis deinfestação. Neste estudo, foram avaliadas as taxas diárias de ácaros vivos e mortos encontrados no fundo das colméias de cinco colônias de abelhas africanizadas. Durante 15 dias de observações, foi verificado significativo aumento de ácaros no fundo da colméia �

Breeding system and reproductive skew in a highly polygynous ant population

DEFF Research Database (Denmark)

Haag-Liautard, C.; Pedersen, Jes Søe; Ovaskainen, O.

2008-01-01

of mature queens by mark-release-recapture in 29 nests and dissected a sub-sample of queens to assess their reproductive status. We also used microsatellites to estimate relatedness within and between all classes of nestmates (queens, their mates, worker brood, queen brood and male brood). Queen number...... Factors affecting relatedness among nest members in ant colonies with high queen number are still poorly understood. In order to identify the major determinants of nest kin structure, we conducted a detailed analysis of the breeding system of the ant Formica exsecta. We estimated the number...... was very high, with an arithmetic mean of 253 per nest. Most queens (90%) were reproductively active, consistent with the genetic analyses revealing that there was only a minimal reproductive skew among nestmate queens. Despite the high queen number and low reproductive skew, almost all classes...

Are queen ants inhibited by their own pheromone?

DEFF Research Database (Denmark)

Holman, L.; Leroy, C.; Jørgensen, Charlotte

2013-01-01

. Communication in social insects is predominantly chemical, and the mechanisms regulating processes such as reproductive division of labor are becoming increasingly well understood. Recently, a queen cuticular hydrocarbon (3-MeC31) that inhibits worker reproduction and aggression was isolated in the ant Lasius...... niger. Here, we find that this pheromone also has a weak negative effect on queen productivity and oogenesis. Because 3-MeC31 is present on both queens and their brood, we suggest that it is used by ants of both castes to adjust their fecundity to the amount of developing brood and the presence of other...

Chromosome aberrations in pesticide-exposed greenhouse workers

DEFF Research Database (Denmark)

Lander, B F; Knudsen, Lisbeth E.; Gamborg, M O

2000-01-01

OBJECTIVES: The aim of this study was to investigate the possibility of subtoxic exposure to pesticides causing chromosome aberrations in greenhouse workers. METHODS: In a cross-sectional and prospective study design chromosome aberration frequencies in cultured lymphocytes were examined for 116...... greenhouse workers exposed to a complex mixture of almost 50 insecticides, fungicides, and growth regulators and also for 29 nonsmoking, nonpesticide-exposed referents. RESULTS: The preseason frequencies of chromosome aberrations were slightly but not statistically significantly elevated for the greenhouse...... workers when they were compared with the referents. After a summer season of pesticide spraying in the greenhouses, the total frequencies of cells with chromosome aberrations were significantly higher than in the preseason samples (P=0.02) and also higher than for the referents (P=0.05). This finding...

The Circadian Clock of the Ant Camponotus floridanus Is Localized in Dorsal and Lateral Neurons of the Brain.

Science.gov (United States)

Kay, Janina; Menegazzi, Pamela; Mildner, Stephanie; Roces, Flavio; Helfrich-Förster, Charlotte

2018-06-01

The circadian clock of social insects has become a focal point of interest for research, as social insects show complex forms of timed behavior and organization within their colonies. These behaviors include brood care, nest maintenance, foraging, swarming, defense, and many other tasks, of which several require social synchronization and accurate timing. Ants of the genus Camponotus have been shown to display a variety of daily timed behaviors such as the emergence of males from the nest, foraging, and relocation of brood. Nevertheless, circadian rhythms of isolated individuals have been studied in few ant species, and the circadian clock network in the brain that governs such behaviors remains completely uncharacterized. Here we show that isolated minor workers of Camponotus floridanus exhibit temperature overcompensated free-running locomotor activity rhythms under constant darkness. Under light-dark cycles, most animals are active during day and night, with a slight preference for the night. On the neurobiological level, we show that distinct cell groups in the lateral and dorsal brain of minor workers of C. floridanus are immunostained with an antibody against the clock protein Period (PER) and a lateral group additionally with an antibody against the neuropeptide pigment-dispersing factor (PDF). PER abundance oscillates in a daily manner, and PDF-positive neurites invade most parts of the brain, suggesting that the PER/PDF-positive neurons are bona fide clock neurons that transfer rhythmic signals into the relevant brain areas controlling rhythmic behavior.

Pheromonal regulation of starvation resistance in honey bee workers ( Apis mellifera)

Science.gov (United States)

Fischer, Patrick; Grozinger, Christina M.

2008-08-01

Most animals can modulate nutrient storage pathways according to changing environmental conditions, but in honey bees nutrient storage is also modulated according to changing behavioral tasks within a colony. Specifically, bees involved in brood care (nurses) have higher lipid stores in their abdominal fat bodies than forager bees. Pheromone communication plays an important role in regulating honey bee behavior and physiology. In particular, queen mandibular pheromone (QMP) slows the transition from nursing to foraging. We tested the effects of QMP exposure on starvation resistance, lipid storage, and gene expression in the fat bodies of worker bees. We found that indeed QMP-treated bees survived much longer compared to control bees when starved and also had higher lipid levels. Expression of vitellogenin RNA, which encodes a yolk protein that is found at higher levels in nurses than foragers, was also higher in the fat bodies of QMP-treated bees. No differences were observed in expression of genes involved in insulin signaling pathways, which are associated with nutrient storage and metabolism in a variety of species; thus, other mechanisms may be involved in increasing the lipid stores. These studies demonstrate that pheromone exposure can modify nutrient storage pathways and fat body gene expression in honey bees and suggest that chemical communication and social interactions play an important role in altering metabolic pathways.

Cytochalasin-b micronucleus test of peripheral blood lymphocytes of Kozloduy NPP workers

International Nuclear Information System (INIS)

Hadjidekova, V.; Hristova, R.; Atanassova, P.; Stainova, A.; Popova, L.

2006-01-01

Full text: The cytokinesis-block micronucleus assay in peripheral blood lymphocytes was applied to evaluate occupational radiation exposure of 65 nuclear power plant workers. Blood samples were collected from 43 workers aged between 32-54 years, mean age 41,7 years. The accumulated radiation doses for each subject varied between 7,9 - 766,4 mSv, mean level of the whole group is 237,78 mSv. Controls were 22 healthy individuals, (13 male and 9 female), aged between 27-52 years, mean age 38,8 years, selected from the administrative staff. All subjects participating in this study were interviewed concerning health status, professional history, smoking habit and other aspects relevant to the study. At least 1000 binucleated cells were analysed per person. The detected frequencies of micronuclei in the control group were ranged between 4.0 and 23.5 per 1000 binucleated cells, with the average incidence yield of 12.16 ±5.59 %. The mean group value of the frequency of micronuclei in peripheral lymphocytes of exposed workers was found to be 18.46±6.72 % in 1000 cells. The difference between the mean frequency of micronuclei in the group of exposed subjects and the control group was statistically significant (P<0,001). The correlation coefficient for duration of employment and accumulated doses is 0,30 (P<0,05). After 1,5 Gy in vitro irradiation of peripheral blood from investigated workers and controls a decreased radiosensitivity of NPP workers is detected using micronucleus assay. Decreased radiosensitivity of the professionally exposed workers could be due to the phenomenon of adaptive response. Micronucleus assay in peripheral blood lymphocytes is useful approach in cytogenetic monitoring of occupationally exposed nuclear industry workers

Evaluation of workers exposed to dust containing hard metals and aluminum oxide.

Science.gov (United States)

Schwarz, Y; Kivity, S; Fischbein, A; Abraham, J L; Fireman, E; Moshe, S; Dannon, Y; Topilsky, M; Greif, J

1998-08-01

Fourteen worker exposed to hard metals and aluminum oxide were evaluated. Six heavily exposed workers underwent bronchoscopy and bronchoalveolar lavage, and five workers underwent transbronchial biopsy. Microchemical analysis of transbronchial biopsies showed a high lung burden of exogenous particles, especially metal related to their hard metals exposure. Lung tissue and cellular changes, which were associated with exposure to hard metal and aluminum oxide, corresponded well with the microanalytic test results. Three workers had at biopsy diffuse interstitial inflammatory changes: two of them were asymptomatic with normal chest X-ray films, and one had clinically evident disease with severe giant cell inflammation. Two other workers showed focal inflammation. The worker showing clinical disease and one asymptomatic worker with interstitial inflammatory changes had evaluated bronchoalveolar lavage fluid-eosinophilia counts. These two were father (with clinical disease) and son (asymptomatic).

Mobile Applications for Knowledge Workers and Field Workers

Directory of Open Access Journals (Sweden)

Stefan Stieglitz

2015-01-01

Full Text Available In recent years, the diffusion of mobile applications (mobile apps has risen significantly. Nowadays, mobile business apps are strongly emerging in business, enhancing productivity and employees’ satisfaction, whilst the usage of customized individual enterprise apps is still an exception. Standardized business apps enable basic functionalities, for example, mobile data storage and exchange (e.g., Dropbox, communication (e.g., Skype, and other routine processes, which support mobile workers. In addition, mobile apps can, for example, increase the flexibility of mobile workers by easing the access to firm’s information from outside the enterprise and by enabling ubiquitous collaboration. Hence, mobile apps can generate competitive advantages and can increase work efficiency on a broad scale. But mobile workers form no coherent group. Our research reveals, based on two case studies, that they can be clustered into two groups: knowledge workers and field workers. Knowledge workers and field workers fulfill different tasks and work in different environments. Hence, they have different requirements for mobile support. In this paper we conclude that standardized mobile business apps cannot meet the different requirements of various groups of mobile workers. Task- and firm-specific (individualized requirements determine the specification, implementation, and application of mobile apps.

[Occupational risk related to optical radiation exposure in construction workers].

Science.gov (United States)

Gobba, F; Modenese, A

2012-01-01

Optical Radiation is a relevant occupational risk in construction workers, mainly as a consequence of the exposure to the ultraviolet (UV) component of solar radiation (SR). Available data show that UV occupational limits are frequently exceeded in these workers, resulting in an increased occupational risk of various acute and chronic effects, mainly to skin and to the eye. One of the foremost is the carcinogenic effect: SR is indeed included in Group 1 IARC (carcinogenic to humans). UV exposure is related to an increase of the incidence of basal cell carcinoma, squamous cell carcinoma of the skin and cutaneous malignant melanoma (CMM). The incidence of these tumors, especially CMM, is constantly increasing in Caucasians in the last 50 years. As a conclusion, an adequate evaluation of the occupational risk related to SR, and adequate preventive measures are essential in construction workers. The role of occupational physicians in prevention is fundamental.

Impact of organic solvents and environmental pollutants on the physiological function in petrol filling workers.

Science.gov (United States)

Uzma, Nazia; Salar, B M Khaja Mohinuddin; Kumar, B Santhosh; Aziz, Nusrat; David, M Anthony; Reddy, V Devender

2008-09-01

Long term exposure to solvents and air pollutants can lead to deleterious effects on respiratory, haematological and thyroid functioning. The aim of this study was to investigate whether chronic exposure to solvents like benzene and pollutants like carbon monoxide in petrol filling workers had adverse effect on blood parameters, thyroid and respiratory functions. The study group consisted of 42 healthy, non-smoker petrol filling workers, aged 20-50 years with work (exposure) duration from 2-15 years while 36 healthy subjects of the same age group served as controls. Physical examination and measurement of pulmonary functions by portable electronic spirometer were performed. Complete blood pictures (CBP) were determined by normal haematology lab procedure and hormones by Chemiluminescence immunoassay (CLIA) light absorption techniques. There was a significant decrease in the lung volumes and capacities; the restrictive pattern was more prevalent in the workers when compared with the control groups. But in the workers exposed for long period (more than 10 years) the restrictive pattern was changed to mixed pattern. A significant increase in haemoglobin (Hb) (>16 mg %) and red blood cells (RBC) (5.4 million cells/mm3) were observed in workers with longer period of exposure when compared with the control subjects (14.483 mg% and 4.83 million cells/mm3 for Hb and RBC respectively). White blood cell count except eosinophils and platelets were significantly lower in workers compared to controls. Marked increase in the tetra iodothyroinine (T4), free thyroxine (T4F) level and significant decrease in thyroid stimulating hormones (TSH), and tri-iodothyronine (T3) were observed between long term exposed and non-exposed groups. Till now researchers focused only on the effect of solvents in workers professionally exposed to solvents without considering the effect of concomittant air pollution. The result obtained from present study indicates that there is a significant toxic

Gustatory Perception and Fat Body Energy Metabolism Are Jointly Affected by Vitellogenin and Juvenile Hormone in Honey Bees

OpenAIRE

Wang, Ying; Brent, Colin S.; Fennern, Erin; Amdam, Gro V.

2012-01-01

Honey bees (Apis mellifera) provide a system for studying social and food-related behavior. A caste of workers performs age-related tasks: young bees (nurses) usually feed the brood and other adult bees inside the nest, while older bees (foragers) forage outside for pollen, a protein/lipid source, or nectar, a carbohydrate source. The workers' transition from nursing to foraging and their foraging preferences correlate with differences in gustatory perception, metabolic gene expression, and e...

Varroa destructor mite in Africanized honeybee colonies Apis mellifera L. under royal jelly or honey production

Directory of Open Access Journals (Sweden)

Pedro da Rosa Santos

2015-08-01

Full Text Available This study evaluated the level of invasion of Varroa mite into worker brood cells, the infestation rate on adult worker honeybees, total and effective reproduction rates of the mite in Africanized honeybee colonies under royal jelly or honey production. Invasion and infestation rates were not statistically different between honeybee colonies producing honey or royal jelly and the averages for these parameters were 5.79 and 8.54%, respectively. Colonies producing honey presented a higher (p < 0.05 total and effective reproduction of Varroa than colonies producing royal jelly. There was a negative correlation between levels of invasion and infestation with minimum external temperature, relative humidity and rainfall. The variables month and season influenced the development of the mite, but rates were low and within the range normally found in Brazil for Africanized honeybee colonies, which confirm the greater resistance of these honeybees to Varroa destructor than European honeybees.

Tiny individuals attached to a new Silurian arthropod suggest a unique mode of brood care

Science.gov (United States)

Briggs, Derek E. G.; Siveter, Derek J.; Siveter, David J.; Sutton, Mark D.

2016-04-01

The ˜430-My-old Herefordshire, United Kingdom, Lagerstätte has yielded a diversity of remarkably preserved invertebrates, many of which provide fundamental insights into the evolutionary history and ecology of particular taxa. Here we report a new arthropod with 10 tiny arthropods tethered to its tergites by long individual threads. The head of the host, which is covered by a shield that projects anteriorly, bears a long stout uniramous antenna and a chelate limb followed by two biramous appendages. The trunk comprises 11 segments, all bearing limbs and covered by tergites with long slender lateral spines. A short telson bears long parallel cerci. Our phylogenetic analysis resolves the new arthropod as a stem-group mandibulate. The evidence suggests that the tethered individuals are juveniles and the association represents a complex brooding behavior. Alternative possibilities—that the tethered individuals represent a different epizoic or parasitic arthropod—appear less likely.

Assessment of vinyl chloride-induced DNA damage in lymphocytes of plastic industry workers using a single-cell gel electrophoresis technique.

Science.gov (United States)

Awara, W M; El-Nabi, S H; El-Gohary, M

1998-06-26

DNA damage and the formation of stable carcinogen-DNA adducts are considered critical events in the initiation of the carcinogenic process. This study was carried out to assess whether exposure of plastics industry workers to the vinyl chloride monomer (VCM) for different periods of time would cause DNA damage, using the single-cell gel electrophoresis (SCGE) technique. Levels of DNA damage was assessed by both extent of DNA migration and numbers of DNA damaged spots in the peripheral blood lymphocytes from 32 plastics workers with different periods of exposure to VCM; they were evaluated by comparison with a group of non-exposed individuals. It was found that plastics workers who were exposed to VCM for different periods of time showed significantly increased levels of DNA damage compared with the non-exposed subjects. There was a significant correlation between the severity of DNA damage and duration of exposure. However, no significant correlation was found between the age of all subjects and DNA damage. Concentrations of VCM in the air inside the factory were found to be significantly higher than values in non-exposed areas, despite being lower than the threshold limit value (TLV). Our results encourage the application of SCGE as a sensitive, simple, fast and useful technique in the regular health screening of workers occupationally exposed to VCM (even at concentrations below the TLV) to assess the possibility of any DNA damage.

Micronuclei Frequencies in Lymphocytes of Nuclear Malaysia Radiation Workers

International Nuclear Information System (INIS)

Mohd Rodzi Ali; Aisyah Mohd Yusof; Rahimah Abdul Rahim; Juliana Mahamat Napiah; Yahaya Talib; Shafii Khamis

2016-01-01

The objective of the study is to investigate the frequency of cell aberration in lymphocytes of the Nuklear Malaysia radiation workers. A total of 58 blood samples were collected from the radiation workers during their routine medical examination. The donor age range is between 23 to 58 years, 31 male and 27 female. Blood samples were cultured according to the standard protocol recommended by the International Atomic Energy Agency. The mean micronuclei (MN) is 23.5 ± 0.9 MN/ 1000 binucleate, with the median value of 24 MN/ 1000 binucleate. The lowest number of MN was 9, and the highest was 43. There is no correlation between the number of MN in blood and yearly cumulative dose for radiation workers. The results indicate the MN expression due to small radiation exposure is almost negligible in Nuclear Malaysia radiation workers. (author)

Worker Entrepreneurship.

Science.gov (United States)

Doucouliagos, Chris

1992-01-01

Evaluates the experience of worker entrepreneurship, highlighting successes and failures in Europe, and analyzes the relative importance of factors to worker entrepreneurship such as access to finance, education and training, organizational culture, and worker risk taking. (JOW)

Catalysts of worker-to-worker violence and incivility in hospitals.

Science.gov (United States)

Hamblin, Lydia E; Essenmacher, Lynnette; Upfal, Mark J; Russell, Jim; Luborsky, Mark; Ager, Joel; Arnetz, Judith E

2015-09-01

To identify common catalysts of worker-to-worker violence and incivility in hospital settings. Worker-to-worker violence and incivility are prevalent forms of mistreatment in healthcare workplaces. These are forms of counterproductive work behaviour that can lead to negative outcomes for employees, patients and the organisation overall. Identifying the factors that lead to co-worker mistreatment is a critical first step in the development of interventions targeting these behaviours. Retrospective descriptive study. Qualitative content analysis was conducted on the total sample (n = 141) of employee incident reports of worker-to-worker violence and incivility that were documented in 2011 at a large American hospital system. More than 50% of the incidents involved nurses, and the majority of incidents did not involve physical violence. Two primary themes emerged from the analysis: Work Behaviour and Work Organisation. Incidents in the Work Behaviour category were often sparked by unprofessional behaviour, disagreement over responsibilities for work tasks or methods of patient care, and dissatisfaction with a co-worker's performance. Incidents in the Work Organisation category involved conflicts or aggression arising from failure to following protocol, patient assignments, limited resources and high workload. Incidents of worker-to-worker violence and incivility stemmed from dissatisfaction with employee behaviour or from organisational practices or work constraints. These incident descriptions reflect worker dissatisfaction and frustration, resulting from poor communication and collaboration between employees, all of which threaten work productivity. Violence and incivility between hospital employees can contribute to turnover of top performers, hinder effective teamwork and jeopardise the quality of patient care. Identification of common catalysts for worker-to-worker violence and incivility informs the development of mistreatment prevention programmes that can be

Local behavioral rules sustain the cell allocation pattern in the combs of honey bee colonies (Apis mellifera).

Science.gov (United States)

Montovan, Kathryn J; Karst, Nathaniel; Jones, Laura E; Seeley, Thomas D

2013-11-07

In the beeswax combs of honey bees, the cells of brood, pollen, and honey have a consistent spatial pattern that is sustained throughout the life of a colony. This spatial pattern is believed to emerge from simple behavioral rules that specify how the queen moves, where foragers deposit honey/pollen and how honey/pollen is consumed from cells. Prior work has shown that a set of such rules can explain the formation of the allocation pattern starting from an empty comb. We show that these rules cannot maintain the pattern once the brood start to vacate their cells, and we propose new, biologically realistic rules that better sustain the observed allocation pattern. We analyze the three resulting models by performing hundreds of simulation runs over many gestational periods and a wide range of parameter values. We develop new metrics for pattern assessment and employ them in analyzing pattern retention over each simulation run. Applied to our simulation results, these metrics show alteration of an accepted model for honey/pollen consumption based on local information can stabilize the cell allocation pattern over time. We also show that adding global information, by biasing the queen's movements towards the center of the comb, expands the parameter regime over which pattern retention occurs. © 2013 Published by Elsevier Ltd. All rights reserved.

Population differentiation or species formation across the Indian and the Pacific Oceans? An example from the brooding marine hydrozoan Macrorhynchia phoenicea.

Science.gov (United States)

Postaire, Bautisse; Gélin, Pauline; Bruggemann, J Henrich; Pratlong, Marine; Magalon, Hélène

2017-10-01

Assessing population connectivity is necessary to construct effective marine protected areas. This connectivity depends, among other parameters, inherently on species dispersal capacities. Isolation by distance (IBD) is one of the main modes of differentiation in marine species, above all in species presenting low dispersal abilities. This study reports the genetic structuring in the tropical hydrozoan Macrorhynchia phoenicea α ( sensu Postaire et al ., 2016a), a brooding species, from 30 sampling sites in the Western Indian Ocean and the Tropical Southwestern Pacific, using 15 microsatellite loci. At the local scale, genet dispersal relied on asexual propagation at short distance, which was not found at larger scales. Considering one representative per clone, significant positive F IS values (from -0.327*** to 0.411***) were found within almost all sites. Gene flow was extremely low at all spatial scales, among sites within islands (11,000 km distance), with significant pairwise F ST values (from 0.035*** to 0.645***). A general pattern of IBD was found at the Indo-Pacific scale, but also within ecoregions in the Western Indian Ocean province. Clustering and network analyses identified each island as a potential independent population, while analysis of molecular variance indicated that population genetic differentiation was significant at small (within island) and intermediate (among islands within province) spatial scales. As shown by this species, a brooding life cycle might be corollary of the high population differentiation found in some coastal marine species, thwarting regular dispersal at distances more than a few kilometers and probably leading to high cryptic diversity, each island housing independent evolutionary lineages.

Thermoregulation strategies in ants in comparison to other social insects, with a focus on Formica rufa [v1; ref status: indexed, http://f1000r.es/2fv

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Štěpánka Kadochová

2013-12-01

Full Text Available Temperature influences every aspect of ant biology, especially metabolic rate, growth and development. Maintenance of high inner nest temperature increases the rate of sexual brood development and thereby increases the colony fitness. Insect societies can achieve better thermoregulation than solitary insects due to the former’s ability to build large and elaborated nests and display complex behaviour. In ants and termites the upper part of the nest, the mound, often works as a solar collector and can also have an efficient ventilation system. Two thermoregulatory strategies could be applied. Firstly the ants use an increased thermal gradient available in the mound for brood relocation. Nurse workers move the brood according to the thermal gradients to ensure the ideal conditions for development. A precise perception of temperature and evolution of temperature preferences are needed to make the correct choices. A second thermoregulatory strategy used by mound nesting ants is keeping a high temperature inside large nests. The unique thermal and insulation properties of the nest material help to maintain stable conditions, which is the case of the Wood ant genus Formica. Ants can regulate thermal loss by moving nest aggregation and alternating nest ventilation. Metabolic heat produced by ant workers or associated micro organisms is an important additional source of heat which helps to maintain thermal homeostasis in the nest.

Thermoregulation strategies in ants in comparison to other social insects, with a focus on red wood ants (Formica rufa group [v2; ref status: indexed, http://f1000r.es/35p

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Štěpánka Kadochová

2014-03-01

Full Text Available Temperature influences every aspect of ant biology, especially metabolic rate, growth and development. Maintenance of high inner nest temperature increases the rate of sexual brood development and thereby increases the colony fitness. Insect societies can achieve better thermoregulation than solitary insects due to the former’s ability to build large and elaborated nests and display complex behaviour. In ants and termites the upper part of the nest, the mound, often works as a solar collector and can also have an efficient ventilation system. Two thermoregulatory strategies could be applied. Firstly the ants use an increased thermal gradient available in the mound for brood relocation. Nurse workers move the brood according to the thermal gradients to ensure the ideal conditions for development. A precise perception of temperature and evolution of temperature preferences are needed to make the correct choices. A second thermoregulatory strategy used by mound nesting ants is keeping a high temperature inside large nests. The unique thermal and insulation properties of the nest material help to maintain stable conditions, which is the case of the Wood ant genus Formica. Ants can regulate thermal loss by moving nest aggregation and alternating nest ventilation. Metabolic heat produced by ant workers or associated micro organisms is an important additional source of heat which helps to maintain thermal homeostasis in the nest.

Impact of Organic Solvents and Environmental Pollutants on the Physiological Function in Petrol Filling Workers

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V. Devender Reddy

2008-09-01

Full Text Available Long term exposure to solvents and air pollutants can lead to deleterious effects on respiratory, haematological and thyroid functioning. The aim of this study was to investigate whether chronic exposure to solvents like benzene and pollutants like carbon monoxide in petrol filling workers had adverse effect on blood parameters, thyroid and respiratory functions. The study group consisted of 42 healthy, non-smoker petrol filling workers, aged 20-50 years with work (exposure duration from 2-15 years while 36 healthy subjects of the same age group served as controls. Physical examination and measurement of pulmonary functions by portable electronic spirometer were performed. Complete blood pictures (CBP were determined by normal haematology lab procedure and hormones by Chemiluminescence immunoassay (CLIA light absorption techniques. There was a significant decrease in the lung volumes and capacities; the restrictive pattern was more prevalent in the workers when compared with the control groups. But in the workers exposed for long period (more than 10 years the restrictive pattern was changed to mixed pattern. A significant increase in haemoglobin (Hb (>16 mg % and red blood cells (RBC (5.4 million cells/mm3 were observed in workers with longer period of exposure when compared with the control subjects (14.483 mg% and 4.83 million cells/mm3 for Hb and RBC respectively. White blood cell count except eosinophils and platelets were significantly lower in workers compared to controls. Marked increase in the tetra iodothyroinine (T4, free thyroxine (T4F level and significant decrease in thyroid stimulating hormones (TSH, and tri-iodothyronine (T3 were observed between long term exposed and non – exposed groups. Till now researchers focused only on the effect of solvents in workers professionally exposed to solvents without considering the effect of concomittant air pollution. The result obtained from present study indicates that there is

Parasite dispersal risk tolerance is mediated by its reproductive value.

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Nolan, Maxcy P; Delaplane, Keith S

2017-10-01

Parasite dispersal theory draws heavily upon epidemiological SIR models in which host status (susceptible (S), infected (I), or recovered (R)) is used to study parasite dispersal evolution. In contrast to these extrinsically host-centric drivers, in this study we focus on an intrinsic driver, the parasite's reproductive value (predicted future offspring) as a regulator of the extent to which the individual will engage in risky dispersal behaviour. As a model system we use the honeybee Apis mellifera and its ectoparasite, the mite Varroa destructor . Mite reproduction happens exclusively inside cells of bee brood, and newly emerged fecund mites may parasitize either a homocolonial brood cell (low risk dispersal) or emigrate to a new bee colony via phoretic attachment to mature forager bees (high risk dispersal). In an empirical bioassay, prepartum mites (high reproductive value) and postpartum mites (low reproductive value) were offered a choice of newly emerged homocolonial worker bees (low risk), homocolonial pollen forager bees (high risk), or heterocolonial pollen foragers (high risk). A preference for newly emerged bees was earlier and more strongly sustained among prepartum mites. This suggests comparatively greater dispersal risk tolerance among postpartum mites with lower reproductive value. A dangerous bid for dispersal may be adaptive if the individual has already successfully reproduced and the rewards for successful dispersal are sufficiently large.

Climate change effects on migration phenology may mismatch brood parasitic cuckoos and their hosts.

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Saino, Nicola; Rubolini, Diego; Lehikoinen, Esa; Sokolov, Leonid V; Bonisoli-Alquati, Andrea; Ambrosini, Roberto; Boncoraglio, Giuseppe; Møller, Anders P

2009-08-23

Phenological responses to climate change vary among taxa and across trophic levels. This can lead to a mismatch between the life cycles of ecologically interrelated populations (e.g. predators and prey), with negative consequences for population dynamics of some of the interacting species. Here we provide, to our knowledge, the first evidence that climate change might disrupt the association between the life cycles of the common cuckoo (Cuculus canorus), a migratory brood parasitic bird, and its hosts. We investigated changes in timing of spring arrival of the cuckoo and its hosts throughout Europe over six decades, and found that short-distance, but not long-distance, migratory hosts have advanced their arrival more than the cuckoo. Hence, cuckoos may keep track of phenological changes of long-distance, but not short-distance migrant hosts, with potential consequences for breeding of both cuckoo and hosts. The mismatch to some of the important hosts may contribute to the decline of cuckoo populations and explain some of the observed local changes in parasitism rates of migratory hosts.

Reproductive-tactic-specific variation in sperm swimming speeds in a shell-brooding cichlid.

Science.gov (United States)

Fitzpatrick, J L; Desjardins, J K; Milligan, N; Montgomerie, R; Balshine, S

2007-08-01

Theory predicts that males experiencing elevated levels of sperm competition will invest more in gonads and produce faster-swimming sperm. Although there is ample evidence in support of the first prediction, few studies have examined sperm swimming speed in relation to sperm competition. In this study, we tested these predictions from sperm competition theory by examining sperm characteristics in Telmatochromis vittatus, a small shell-brooding cichlid fish endemic to Lake Tanganyika. Males exhibit four different reproductive tactics: pirate, territorial, satellite, and sneaker. Pirate males temporarily displace all other competing males from a shell nest, whereas sneaker males always release sperm in the presence of territorial and satellite males. Due to the fact that sneakers spawn in the presence of another male, sneakers face the highest levels of sperm competition and pirates the lowest, whereas satellites and territorials experience intermediate levels. In accordance with predictions, sperm from sneakers swam faster than sperm from males adopting the other reproductive tactics, whereas sperm from pirates was slowest. Interestingly, we were unable to detect any variation in sperm tail length among these reproductive tactics. Thus, sperm competition appears to have influenced sperm energetics in this species without having any influence on sperm size.

Effects of a combined hatching and brooding system on hatchability, chick weight, and mortality in broilers.

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van de Ven, L J F; van Wagenberg, A V; Groot Koerkamp, P W G; Kemp, B; van den Brand, H

2009-11-01

Chicks hatch over a time window of approximately 36 to 48 h and are removed from the hatchers only when the majority of the chicks has hatched. Consequently, chicks are exposed to prolonged posthatch holding periods and delays in feed and water access, leading to dehydration and impaired posthatch performance. It is questionable whether the physiological requirements of the hatchlings can be met with current hatching systems. An alternative system that may better match the requirements of the hatchlings is a system that combines the hatching and brooding phase, so that feed and water can be provided immediately after hatch. Such a system, named Patio, was developed in the Netherlands and tested from 2006 to 2008, to evaluate effects on hatchability and early performance of broilers. This paper describes the Patio system and the results from these tests. A total of 21 broiler production trials (780,686 eggs) in the Patio system were evaluated at 3 locations and compared with control hatches of eggs of the same parental flock in the hatchery. Hatchability in the Patio was on average 1.45, 1.83, and 1.86% higher at location 1, 2, and 3, respectively. However, in the calculation of the hatchability in the Patio, possible second grade chicks were included, whereas these were excluded in the calculation of hatchability in the hatchery. Additionally, in the hatchery, the hatching process was interrupted earlier than in the Patio, meaning that possible late hatching chicks remained in the flock in the Patio, but not in the hatchery. In 3 trials, the Patio chicks were 11.6 to 16.3% heavier at d 0, when the hatchery chicks were placed in the broiler house. Mean cumulative 7-d mortality was only assessed in the Patio and was 1.27, 1.09, and 1.43% at location 1, 2, and 3, respectively. The Patio system appears to function as an alternative to current hatching and brooding systems. Further studies are required to determine to what extent the higher hatchability is due to second

Changes in buccal micronucleus cytome parameters associated with smokeless tobacco and pesticide exposure among female tea garden workers of Assam, India.

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Kausar, Afifa; Giri, Sarbani; Roy, Prasenjit; Giri, Anirudha

2014-03-01

Assam is the highest tea producing state in India. A large number of workers are engaged in various units of tea industry. There are few reports on the health status of the tea garden workers. The present cytogenetic biomonitoring study was undertaken to investigate the genotoxic effect associated with workers in tea industries in southern Assam. Smokeless tobacco chewing along with betel nut is very common practice among the workers. Workers also get exposed periodically to mixture of pesticides. Employing buccal micronucleus cytome assay, exfoliated buccal cells were analyzed in 90 female tea garden and compared to 90 age and sex matched non-chewer control as well as 70 chewers who are not tea garden workers. Statistically significant (pworkers compared to both the control groups. The frequency of cell proliferation biomarkers was highest in the chewer controls whereas genotoxic and cell death parameters were highest in tea garden workers. Linear correlation analysis revealed strong positive correlation between the duration of occupation and the frequency of micronucleus (r=0.597; pworkers was relatively lower compared to the control group. Pesticide exposure and chewing areca nut along with smokeless tobacco use may be responsible for changes in cytome parameters in exfoliated buccal cells. Copyright © 2013 Elsevier GmbH. All rights reserved.

ALIMENTARY CANAL ANATOMY AND HISTOLOGY OF THE WORKER TERMITE NEOTERMES BOSEI

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LEKSONO EKOPURANTO HARIPRABOWO

2006-01-01

Full Text Available As social insects, termites live in a colony that consist of reproductive (drone and queen, and non-reproductive (soldiers and workers castes. Workers obtain their food directly from wood, humus, and other substances that contain cellulose. The objective of this study was to examine the alimentary canal of the Neotermes bosei workers. Observations of gut transverse section were carried out through the length, perimeter, and area of each alimentary canal region. The results showed that total length of N. bosei alimentary canal was 13.71+1.28 mm. The canal was divided into fore-, mid-, and hindgut which were 24, 28, and 48%, respectively of the gut total length. Two types of alimentary canal epithelial cells were found, i.e. the squamous and transitional cells. Areas covered with thick muscular tissues were crop, proventriculus, and rectum. Proventriculus was characterized with six large dentitions. There was no gastric caeca in N. bosei midgut, which commonly occurred in chewing insect. Secretory cells .wer e observed at proventriculus and ventriculus regions. Cardiac valve was found at the anterior end of ventriculus. Area with the largest outer perimeter was the rectum pouch. Enteric valve had three internal folds.

Honey bee nest thermoregulation: diversity promotes stability.

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Jones, Julia C; Myerscough, Mary R; Graham, Sonia; Oldroyd, Benjamin P

2004-07-16

A honey bee colony is characterized by high genetic diversity among its workers, generated by high levels of multiple mating by its queen. Few clear benefits of this genetic diversity are known. Here we show that brood nest temperatures in genetically diverse colonies (i.e., those sired by several males) tend to be more stable than in genetically uniform ones (i.e., those sired by one male). One reason this increased stability arises is because genetically determined diversity in workers' temperature response thresholds modulates the hive-ventilating behavior of individual workers, preventing excessive colony-level responses to temperature fluctuations.

Vasculature of the hive: heat dissipation in the honey bee ( Apis mellifera) hive

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Bonoan, Rachael E.; Goldman, Rhyan R.; Wong, Peter Y.; Starks, Philip T.

2014-06-01

Eusocial insects are distinguished by their elaborate cooperative behavior and are sometimes defined as superorganisms. As a nest-bound superorganism, individuals work together to maintain favorable nest conditions. Residing in temperate environments, honey bees ( Apis mellifera) work especially hard to maintain brood comb temperature between 32 and 36 °C. Heat shielding is a social homeostatic mechanism employed to combat local heat stress. Workers press the ventral side of their bodies against heated surfaces, absorb heat, and thus protect developing brood. While the absorption of heat has been characterized, the dissipation of absorbed heat has not. Our study characterized both how effectively worker bees absorb heat during heat shielding, and where worker bees dissipate absorbed heat. Hives were experimentally heated for 15 min during which internal temperatures and heat shielder counts were taken. Once the heat source was removed, hives were photographed with a thermal imaging camera for 15 min. Thermal images allowed for spatial tracking of heat flow as cooling occurred. Data indicate that honey bee workers collectively minimize heat gain during heating and accelerate heat loss during cooling. Thermal images show that heated areas temporarily increase in size in all directions and then rapidly decrease to safe levels (<37 °C). As such, heat shielding is reminiscent of bioheat removal via the cardiovascular system of mammals.

Workers of Acromyrmex echinatior leafcutter ants police worker-laid eggs, but not reproductive workers

DEFF Research Database (Denmark)

Dijkstra, Michiel B.; van Zweden, Jelle Stijn; Dirchsen, Maria

2010-01-01

Nonreproductive workers of many eusocial Hymenoptera 'police' the colony, that is, they attack reproductive sister workers or destroy their eggs (unfertilized; developing into haploid males). Several ultimate causes of policing have been proposed, including (1) an increase in colony productivity,...... reproductive workers. We infer that relatedness incentives are the most likely ultimate cause of the evolutionary maintenance of worker-egg policing in A. echinatior. (C) 2010 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved...

Effect of frame size and season on enteric methane (CH4) and carbon dioxide (CO2)emissions in Angus brood cows grazing native tall-grass prairie in central Oklahoma USA

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Effect of frame size and season on enteric methane (CH4) and carbon dioxide (CO2) emissions in Angus brood cows grazing native tall-grass prairie in central Oklahoma, USA J.P.S. Neel USDA ARS, El Reno, OK A reduction in enteric CH4 production in ruminants is associated with improved production effic...

Cytogenetic monitoring of nuclear workers occupationally exposed to ionising radiation

International Nuclear Information System (INIS)

Griciene, B.; Slapsyte, G.; Mierauskiene, J.

2014-01-01

Chromosome aberration (CA) analysis using Giemsa techniques was performed in blood lymphocytes of 84 nuclear workers with cumulative doses of 1-632 mSv during employment periods of 1-25 y. The control group comprised 82 healthy male donors. An estimated CA frequency in the total radiation-exposed group was significantly higher when compared with the controls (2.27 vs. 1.76 CA/100 cells, p 0.05). However, significant increase in the total CA frequency was determined in workers with additional internal exposure (2.54 CA/100 cells, p < 0.05) and those with registered neutron doses (2.95 CA/100 cells, p < 0.01). No correlation was found between CA frequency and occupational exposure dose. Borderline significant correlation was found between duration of employment and total CA (r = 0.218, p = 0.046, Fig. 2) and chromosome-type aberration (r = 0.265, p = 0.015) frequency. (authors)

Cytochrome P450 1B1 mRNA levels in peripheral blood cells and exposure to polycyclic aromatic hydrocarbons in Chinese coke oven workers

Energy Technology Data Exchange (ETDEWEB)

Hanaoka, Tomoyuki; Tsugane, Shoichiro [Epidemiology and Biostatistics Division, National Cancer Center Research Institute East, 6-5-1 Kashiwanoha, Kashiwa-shi, 277-8577 Chiba (Japan); Yamano, Yuko; Kagawa, Jun [Tokyo Womens' Medical University, 8-1 Kawadacho, Shinjuku-ku, 162-8666 Tokyo (Japan); Pan, Guowei; Zhang, Shujuan [Liaoning Provincial Center for Disease Prevention and Control, 42-1 Jixian Street, 110005 Shenyang (China); Hara, Kunio [Institute for Science of Labour, 2-8-14 Miyamae-ku, 216-8501 Kawasaki (Japan); Ichiba, Masayoshi; Zhang, Jiusong [Saga Medical School, 5-1 Nabeshima, Saga-shi, 849-8501 Saga (Japan); Liu, Tiefu; Li, Landi [Angang Public Health and Anti-epidemic Station Lishan District, 23 Shengoushi Yutian Street, 114034 Anshan (China); Takahashi, Ken [University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, 807-8555 Kitakyushu (Japan)

2002-09-16

Cytochrome P450 1B1 (CYP1B1) is induced through the Ah receptor and is involved in the activation of polycyclic aromatic hydrocarbons (PAHs). To determine the validity of a quantitative analysis of CYP1B1 mRNA in peripheral human blood cells for the estimation of PAH exposure, a real-time quantitative polymerase chain reaction method was used to measure the relative levels of CYP1B1 mRNA in 37 Chinese coke oven workers and 13 control workers. A large inter-individual difference in the levels was observed. The average level of the CYP1B1 mRNA in workers at the top work site, where the PAH exposure level from the coke ovens was highest, was significantly higher than in workers at the middle site (P<0.01) or the controls (P=0.02). A non-significant positive correlation was found between the CYP1B1 mRNA levels and urinary 1-hydroxypyrene (R=0.22, P=0.13), and a significant correlation between these mRNA levels and urinary cotinine (R=0.33, P=0.02). It was interesting that a significant positive correlation between CYP1B1 mRNA and 1-hydroxypyrene was observed in subjects with the Leu/Leu type of CYP1B1 Leu432Val polymorphism (R=0.33, P=0.02, n=38) and a non-significant correlation in subjects with the Leu/Val and Val/Val types (R=-0.36, P=0.25, n=12), although the number of subjects in this strata analysis was small. Our preliminary study suggests that PAH exposure in coke ovens and smoking maybe associated with CYP1B1 mRNA levels in peripheral blood cells although mRNA is generally unstable and could be expressed following exposure to other agents.

Do male and female cowbirds see their world differently? Implications for sex differences in the sensory system of an avian brood parasite.

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Esteban Fernández-Juricic

Full Text Available BACKGROUND: Male and female avian brood parasites are subject to different selection pressures: males compete for mates but do not provide parental care or territories and only females locate hosts to lay eggs. This sex difference may affect brain architecture in some avian brood parasites, but relatively little is known about their sensory systems and behaviors used to obtain sensory information. Our goal was to study the visual resolution and visual information gathering behavior (i.e., scanning of brown-headed cowbirds. METHODOLOGY/PRINCIPAL FINDINGS: We measured the density of single cone photoreceptors, associated with chromatic vision, and double cone photoreceptors, associated with motion detection and achromatic vision. We also measured head movement rates, as indicators of visual information gathering behavior, when exposed to an object. We found that females had significantly lower density of single and double cones than males around the fovea and in the periphery of the retina. Additionally, females had significantly higher head-movement rates than males. CONCLUSIONS: Overall, we suggest that female cowbirds have lower chromatic and achromatic visual resolution than males (without sex differences in visual contrast perception. Females might compensate for the lower visual resolution by gazing alternatively with both foveae in quicker succession than males, increasing their head movement rates. However, other physiological factors may have influenced the behavioral differences observed. Our results bring up relevant questions about the sensory basis of sex differences in behavior. One possibility is that female and male cowbirds differentially allocate costly sensory resources, as a recent study found that females actually have greater auditory resolution than males.

The unique dorsal brood pouch of Thermosbaenacea (Crustacea, Malacostraca) and description of an advanced developmental stage of Tulumella unidens from the Yucatan Peninsula (Mexico), with a discussion of mouth part homologies to other Malacostraca

DEFF Research Database (Denmark)

Olesen, Jørgen; Boesgaard, Tom; Iliffe, Thomas M.

2015-01-01

The Thermosbaenacea, a small taxon of crustaceans inhabiting subterranean waters, are unique among malacostracans as they brood their offspring dorsally under the carapace. This habit is of evolutionary interest but the last detailed report on thermosbaenacean development is more than 40 years ol...

Studies on chromosome aberrations in workers occupationally exposed to radiation

Energy Technology Data Exchange (ETDEWEB)

Kim, Jong Hyung; Oh, Hyeon Joo; Shim, Sun Bo; Roh, Hye Won; Lee, Hai Yong [Korea Food and Drug Administration, Seoul (Korea, Republic of); Kang, Soon Ja [Ewha Womens Univ., Seoul (Korea, Republic of)

1998-06-01

Cytogenetic assays for unstable chromosomes were performed on 54 medical radiation workers who are occupationally exposed to radiation and 42 controls. A total of 15,577 metaphase cells were scored. The frequencies of dicentrics and acentric chromosomes on controls were 0.52*10{sup -3} and 0.82*10{sup -2}, respectively. On radiation workers those were 2.28*10{sup -3} and 1.34*10{sup -2}, respectively. Though the frequencies of all types of chromosome aberrations in the workers were higher than those in the controls, the only significant difference was found in the case of dicentrics (P < 0.01). When we considered exposure dose of recent one year, duration of employment and smoking habit in radiation worker, a slight increase was shown in frequency of unstable chromosome aberrations on these workers, but no statistical differences were observed (P > 0.05) except exposure dose of recent one year (P < 0.05). These results could indicate that low level exposure to ionizing radiation can induce unstable chromosome aberrations in blood lymphocytes.

Clusters of deep-sea egg-brooding octopods associated with warm fluid discharge: An ill-fated fragment of a larger, discrete population?

Science.gov (United States)

Hartwell, Anne M.; Voight, Janet R.; Wheat, C. Geoffrey

2018-05-01

Benthic octopods cluster on bare rock on Dorado Outcrop, a 3000 m deep basalt exposure. The outcrop hosts intermittent discharge of relatively cool (up to 12.3 °C) hydrothermal fluid that carries about half as much oxygen as bottom seawater ( 54 μM vs. 108 μM). We analyzed 231 h of video footage and still images taken by sub-sea vehicles in 2013 and 2014 that documented the clustered octopods, members of the poorly-known genus Muusoctopus. The largest cluster (102 octopods) occurred in a 19 m2 area of fluid discharge, where the basalt was sediment-free; individual octopods were also seen across the outcrop. The clustered octopods appeared to be brooding eggs and a total of 11 egg clutches were confirmed. None of the 186 eggs closely examined showed embryonic development. The intermittent fluid discharge may clear the basalt of sediment and attract gravid octopods which then spawn. However, the increased temperature and limited oxygen of the discharging fluids may threaten the octopods' survival. Octopods in/near areas of discharging fluid had significantly higher estimated respiration rates (3.1-9.8 contractions/min) than did octopods away from discharging fluid (0.8-6.0 contractions/min). Warm fluids likely increase the octopods' metabolic rate and thus their oxygen demand but provide only limited oxygen. The resultant physiological stress is hypothesized to eventually kill eggs near fluid discharge. We hypothesize, because these eggs do not survive, the population is sustained by a larger pool of undetectable females that brood their eggs inside cool conduits of this and perhaps other, unstudied basalt outcrops.

The effect of queen and worker adoption on weaver ant (Oecophylla smaragdina) queen fecundity

DEFF Research Database (Denmark)

Offenberg, Joachim; Peng, Renkang; Nielsen, Mogens Gissel

2012-01-01

Incipient ant colonies are often under fierce competition, making fast growth crucial for survival. To increase production, colonies can adopt multiple queens (pleometrosis), fuse with other colonies or rob brood from neighboring colonies. However, different adoption strategies might have different...

Fine-scale analysis of genetic structure in the brooding coral Seriatopora hystrix from the Red Sea

Science.gov (United States)

Maier, E.; Tollrian, R.; Nürnberger, B.

2009-09-01

The dispersal of gametes and larvae plays a key role in the population dynamics of sessile marine invertebrates. Species with internal fertilisation are often associated with very localised larval dispersal, which may cause small-scale patterns of neutral genetic variation. This study on the brooding coral Seriatopora hystrix from the Red Sea focused on the smallest possible scale: Two S. hystrix stands (~100 colonies each) near Dahab were completely sampled, mapped and analysed at five microsatellite markers. The sexual mode of reproduction, the likely occurrence of selfing and the level of immigration were in agreement with previous studies on this species. Contrary to previous findings, both stands were in Hardy-Weinberg proportions. Also, no evidence for spatially restricted larval dispersal within the sampled areas was found. Differences between this and previous studies on S. hystrix could reflect variation in life history or varying environmental conditions, which opens intriguing questions for future research.

Preventive actions taken by workers after workers' health surveillance: a controlled trial.

Science.gov (United States)

Boschman, J S; Van der Molen, H F; Frings-Dresen, M H W; Sluiter, J K

2013-12-01

To evaluate construction workers' preventive actions and occupational physician's (OPs) recommendations after a job-specific workers' health surveillance (WHS) compared with the currently used generic WHS. After the WHS, the OPs' written recommendations were captured. At the 3-month follow-up, the workers were asked about the preventive actions they had undertaken. A generalized linear mixed model was used to compare proportions of workers. At follow-up, the proportion of workers who reported taking preventive actions was significantly higher in the intervention group (80%, 44/55) than in the control group (67%, 80 of 121), (P = 0.04). In the intervention group, the OPs provided a higher proportion of workers with written recommendations (82%, 63 of 77, vs 57%, 69 of 121; P = 0.03). The job-specific WHS aided OPs in providing workers with recommendations and workers in undertaking (job-specific) preventive actions.

Evolution of tolerance by magpies to brood parasitism by great spotted cuckoos.

Science.gov (United States)

Soler, J J; Martín-Gálvez, D; Martínez, J G; Soler, M; Canestrari, D; Abad-Gómez, J M; Møller, A P

2011-07-07

Hosts may use two different strategies to ameliorate negative effects of a given parasite burden: resistance or tolerance. Although both resistance and tolerance of parasitism should evolve as a consequence of selection pressures owing to parasitism, the study of evolutionary patterns of tolerance has traditionally been neglected by animal biologists. Here, we explore geographical covariation between tolerance of magpies (Pica pica) and brood parasitism by the great spotted cuckoo (Clamator glandarius) in nine different sympatric populations. We estimated tolerance as the slope of the regression of number of magpie fledglings (i.e. host fitness) on number of cuckoo eggs laid in non-depredated nests (which broadly equals parasite burden). We also estimated prevalence of parasitism and level of host resistance (i.e. rejection rates of mimetic model eggs) in these nine populations. In accordance with the hypothetical role of tolerance in the coevolutionary process between magpies and cuckoos we found geographical variation in tolerance estimates that positively covaried with prevalence of parasitism. Levels of resistance and tolerance were not associated, possibly suggesting the lack of a trade-off between the two kinds of defences against great spotted cuckoo parasitism for magpies. We discuss the results in the framework of a mosaic of coevolutionary interactions along the geographical distribution of magpies and great spotted cuckoos for which we found evidence that tolerance plays a major role.

Chromosome aberrations in workers with exposure to α-particle radiation from internal deposits of plutonium: expectations from in vitro studies and comparisons with workers with predominantly external γ-radiation exposure

Energy Technology Data Exchange (ETDEWEB)

Curwen, Gillian B.; Tawn, E.J. [The University of Manchester, Centre for Integrated Genomic Medical Research (CIGMR), School of Population Health, Faculty of Medical and Human Sciences, Manchester (United Kingdom); Sotnik, Natalia V.; Azizova, Tamara V. [Southern Urals Biophysics Institute (SUBI), Ozyorsk, Chelyabinsk Region 456780 (Russian Federation); Cadwell, Kevin K. [Medical School, Newcastle University, Institute for Cell and Molecular Biosciences, Newcastle upon Tyne (United Kingdom); Hill, Mark A. [University of Oxford, CRUK/MRC Oxford Institute for Radiation Oncology, Gray Laboratories, Oxford (United Kingdom)

2015-05-15

mFISH analysis of chromosome aberration profiles of 47 and 144 h lymphocyte cultures following exposure to 193 mGy α-particle radiation confirmed that the frequency of stable aberrant cells and stable cells carrying translocations remains constant through repeated cell divisions. Age-specific rates and in vitro dose-response curves were used to derive expected translocation yields in nine workers from the Mayak nuclear facility in Russia. Five had external exposure to γ-radiation, two of whom also had exposure to neutrons, and four had external exposure to γ-radiation and internal exposure to α-particle radiation from incorporated plutonium. Doubts over the appropriateness of the dose response used to estimate translocations from the neutron component made interpretation difficult in two of the workers with external exposure, but the other three had translocation yields broadly in line with expectations. Three of the four plutonium workers had translocation yields in line with expectations, thus supporting the application of the recently derived in vitro α-particle dose response for translocations in stable cells. Overall this report demonstrates that with adequate reference in vitro dose-response curves, translocation yield has the potential to be a useful tool in the validation of red bone marrow doses resulting from mixed exposure to external and internal radiation. (orig.)

Long-term respiratory health effects in textile workers.

Science.gov (United States)

Lai, Peggy S; Christiani, David C

2013-03-01

Over 60 million people worldwide work in the textile or clothing industry. Recent studies have recognized the contribution of workplace exposures to chronic lung diseases, in particular chronic obstructive pulmonary disease (COPD). Early studies in textile workers have focused on the relationship between hemp or cotton dust exposure and the development of a syndrome termed byssinosis. The purpose of this review is to evaluate the effect of long-term exposure to organic dust in textile workers on chronic respiratory disease in the broader context of disease classifications, such as reversible or irreversible obstructive lung disease (i.e. asthma or COPD), and restrictive lung disease. Cessation of exposure to cotton dust leads to improvement in lung function. Recent animal models have suggested a shift in the lung macrophage:dendritic cell population ratio as a potential mechanistic explanation for persistent inflammation in the lung due to repeated cotton dust-related endotoxin exposure. Other types of textile dust, such as silk, may contribute to COPD in textile workers. Textile dust-related obstructive lung disease has characteristics of both asthma and COPD. Significant progress has been made in the understanding of chronic lung disease due to organic dust exposure in textile workers.

Six quantitative trait loci influence task thresholds for hygienic behaviour in honeybees (Apis mellifera).

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Oxley, Peter R; Spivak, Marla; Oldroyd, Benjamin P

2010-04-01

Honeybee hygienic behaviour provides colonies with protection from many pathogens and is an important model system of the genetics of a complex behaviour. It is a textbook example of complex behaviour under simple genetic control: hygienic behaviour consists of two components--uncapping a diseased brood cell, followed by removal of the contents--each of which are thought to be modulated independently by a few loci of medium to large effect. A worker's genetic propensity to engage in hygienic tasks affects the intensity of the stimulus required before she initiates the behaviour. Genetic diversity within colonies leads to task specialization among workers, with a minority of workers performing the majority of nest-cleaning tasks. We identify three quantitative trait loci that influence the likelihood that workers will engage in hygienic behaviour and account for up to 30% of the phenotypic variability in hygienic behaviour in our population. Furthermore, we identify two loci that influence the likelihood that a worker will perform uncapping behaviour only, and one locus that influences removal behaviour. We report the first candidate genes associated with engaging in hygienic behaviour, including four genes involved in olfaction, learning and social behaviour, and one gene involved in circadian locomotion. These candidates will allow molecular characterization of this distinctive behavioural mode of disease resistance, as well as providing the opportunity for marker-assisted selection for this commercially significant trait.

Radiological Worker Training: Radiological Worker 2 study guides

International Nuclear Information System (INIS)

1992-10-01

Upon completion of this training course, the participant will have the knowledge to work safely in areas controlled for radiological purposes using proper radiological practices. Radiological Worker H Training, for the worker whose job assignment involves entry into Radiological Buffer Areas and all types of Radiation Contamination and Airborne Radioactivity Areas. This course is designed to prepare the worker to work safely in and around radiological areas and present methods to use to ensure individual radiation exposure is maintained As Low As Reasonably Achievable

The Estonian study of Chernobyl cleanup workers: I. Design and questionnaire data

International Nuclear Information System (INIS)

Tekkel, M.; Rahu, M.; Veidebaum, T.

1997-01-01

Nearly 2% of the male population of Estonia aged 20-39 years were sent to Chernobyl to assist in the cleanup activities after the reactor accident. A cohort of 4,833 cleanup workers was assembled based on multiple and independent sources of information. Information obtained from 3,704 responses to a detailed questionnaire indicated that 63% of the workers were sent to Chernobyl in 1986; 54% were of Estonian and 35% of Russian ethnicity; 72% were married, and 1,164 of their 5,392 children were conceived after the Chernobyl disaster. The workers were less educated than their counterparts than their counterparts in the general population of Estonia, and only 8.5% had attended university. Based on doses entered in workers records, the mean dose was 11 cGy, with only 1.4% over 25 cGy. Nearly 85% of the workers were sent as part of military training activities, and more than half spent in excess of 3 months in the Chernobyl area. Thirty-six percent of the workers reported having worked within the immediate vicinity of the accident site; 11.5% worked on the roofs near the damaged reactor, clearing the highly radioactive debris. The most commonly performed task was the removal and burial of topsoil (55% of the workers). Potassium iodide was given to over 18% of the men. The study design also incorporates biological indicators of exposure based on the glycophorin A mutational assay of red blood cells and chromosome translocation analyses of lymphocytes; record linkage with national cancer registry and mortality registry files to determine cancer incidence and cause-specific mortality; thyroid screening examinations with ultrasound and fine-needle biopsy; and cryopreserved white blood cells and plasma for future molecular studies. Comprehensive studies of Chernobyl cleanup workers have potential to provide a new information about cancer risks due to protracted exposures to ionizing radiation. 21 refs., 1 fig., 11 tabs

Micronuclei in sputum from uranium workers: Epidemiologic application of an evolving cytogenetic technique

International Nuclear Information System (INIS)

Loomis, D.P.

1989-01-01

The exfoliated-cell micronucleus assay is a relatively new cytogenetic technique which can provide a measure of the genetic effect of exposure to carcinogens and mutagens in target tissues where tumors arise among exposed populations. It is responsive to the effects of ionizing radiation and tobacco smoke in some in vivo human cell systems, but has not been extensively field tested as an indicator of lung cancer-related effects, despite the public health importance of exposure to occupational and environmental lung carcinogens. In this study the exfoliated-cell micronucleus assay was used to assess effects of exposure to radon progeny and cigarette smoke in a population of uranium industry workers (including employees in underground and open-pit mines, mills, laboratories, and administrative offices); underground uranium miners experience markedly elevated lung cancer risk because of exposure to ionizing radiation from radon progeny. Ninety-nine workers were selected at random from among workers in Colorado Plateau uranium-related facilities who participated in a workplace sputum cytology screening program from 1964-1988. The prevalence of cells with micronuclei was determined by a manual assay of one sputum specimen for each worker under a light microscope. Occupational and smoking data obtained by interview during screening were used to classify exposure and smoking status at the time the sputum specimen was taken and to obtain information on potential confounders and effect modifiers; underground miners were classified as exposed to radon progeny, and others were considered unexposed. Neither radon progeny exposure nor cigarette smoking had any appreciable effect on the prevalence of micronucleated cells. Crude prevalence ratios were 1.0 (95% CI 0.7-1.4) and 0.9 (95% CI 0.6-1.3), respectively, for radon exposure and smoking

Experience in Rearing Common Carder Bees (Bombus pascuorum Scop., with Some Notes on Three Similar Species: Shrill Carder Bee (B. sylvarum L., Red-shanked Carder Bee (B. ruderarius Müll., and Brown-banded Carder Bee (B. humilis Ill. (Hymenoptera: Apidae

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Vladimír Ptáček

2015-01-01

Full Text Available The rearing method under controlled conditions known for Bombus terrestris was successful in initiating egg-laying for 83% of B. pascuorum queens. After larvae had hatched, fresh pollen pellets needed to be inserted into brood pockets daily. After the first workers had emerged, colony development was advanced by placing them outdoors and supplying them with a sugar solution and pollen. The bees were able to use tightly pressed pollen from small plastic pots inserted near the brood. This feeding resulted in large colonies that produced dozens of young queens. In contrast, colonies managed in the laboratory were unable to utilize pollen in a similar manner. They raised only a few workers and several queens. Mating young queens was easy. It was stimulated by daylight, but in the case of B. humilis by direct sunshine. Several B. pascuorum and B. sylvarum queens were overwintered and began the new generation under artificial conditions. However, a lack of fresh pollen limited the development of colonies outside of the vegetation period.

Worker participation - the Netherlands

OpenAIRE

Kwantes, J.H.

2014-01-01

Worker participation relates to the involvement of workers in the management decision-making processes. In this article attention is focused on worker participation related to occupational safety and health in the Netherlands. Worker participation can refer either to direct or indirect participation by the worker. Indirect participation involves employee representation, while direct participation relates to individual involvement in management’s decision-making processes. In the Framework Dir...

Evaluation of genotoxicity through micronuclei test in workers of car and battery repair garages

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Martino-Roth M.G.

2002-01-01

Full Text Available In this study, the micronuclei test (MNT was applied in exfoliated cells of buccal mucosa, in order to evaluate the genotoxic risk associated with occupational exposure of mechanics, storage battery renovation workers, and car painters. For each individual, 3000 exfoliated buccal cells were analyzed. There was a significantly higher frequency of micronucleated cells (MNC in the exposed workers than in controls. Smoking and drinking habits, age, and working time did not represent significant factors in terms of increasing the production of micronuclei (MN, when the control and the exposed groups were compared. These results allowed to conclude that the studied individuals belong to a risk group and should periodically undergo biological monitoring and proper care.

Structure of ovarioles in adult queens and workers of the common wasp, Vespula germanica (Hymenoptera: Vespidae).

Science.gov (United States)

Jabłońska, A; Biliński, S M

2001-01-01

The ovaries of the common wasp, Vespula germanica are polytrophic-meroistic and consist of 2-3 (workers) or 7 (queens) ovarioles. The ovarioles are differentiated into three regions: a terminal filament, a germarium, and a vitellarium. The germaria of both castes consist of two zones: an anterior zone of germ-cell cluster formation and a posterior one of germ-cell cluster differentiation. The vitellaria comprise 4-6 (workers) or 7-10 (queens) ovarian follicles (egg chambers). Each chamber consists of an oocyte and about 60 isodiametric nurse cells (trophocytes). The egg chambers have been arbitrarily classified into four developmental categories: early and late previtellogenic, vitellogenic, and choriogenic. The process of oogenesis in workers proceeds only up to the onset of the late previtellogenesis. Neither vitellogenic nor choriogenic egg chambers were observed in this caste. During early and late previtellogenesis the envelope of the oocyte nucleus proliferates and becomes highly folded. This process leads to the formation of characteristic organelles, termed accessory nuclei (AN). Although AN arise in the oocytes of both queens and workers, their number in the latter caste is always considerably lower. At the onset of the late previtellogenesis AN start to migrate towards the periphery of the oocyte where they reside till the end of oogenesis. The physiological state of the worker ovaries is discussed in the light of the presented results.

A test of the nest sanitation hypothesis for the evolution of foreign egg rejection in an avian brood parasite rejecter host species.

Science.gov (United States)

Luro, Alec B; Hauber, Mark E

2017-04-01

Hosts of avian brood parasites have evolved diverse defenses to avoid the costs associated with raising brood parasite nestlings. In egg ejection, the host recognizes and removes foreign eggs laid in its nest. Nest sanitation, a behavior similar in motor pattern to egg ejection, has been proposed repeatedly as a potential pre-adaptation to egg ejection. Here, we separately placed blue 3D-printed, brown-headed cowbird (Molothrus ater) eggs known to elicit interindividual variation in ejection responses and semi-natural leaves into American robins' (Turdus migratorius) nests to test proximate predictions that (1) rejecter hosts should sanitize debris from nests more frequently and consistently than accepter hosts and (2) hosts that sanitize their nests of debris prior to the presentation of a foreign egg will be more likely to eject the foreign egg. Egg ejection responses were highly repeatable within individuals yet variable between them, but were not influenced by prior exposure to debris, nor related to sanitation tendencies as a whole, because nearly all individuals sanitized their nests. Additionally, we collected published data for eight different host species to test for a potential positive correlation between sanitation and egg ejection. We found no significant correlation between nest sanitation and egg ejection rates; however, our comparative analysis was limited to a sample size of 8, and we advise that more data from additional species are necessary to properly address interspecific tests of the pre-adaptation hypothesis. In lack of support for the nest sanitation hypothesis, our study suggests that, within individuals, foreign egg ejection is distinct from nest sanitation tendencies, and sanitation and foreign egg ejection may not correlate across species.

Worker participation - the Netherlands

NARCIS (Netherlands)

Kwantes, J.H.

2014-01-01

Worker participation relates to the involvement of workers in the management decision-making processes. In this article attention is focused on worker participation related to occupational safety and health in the Netherlands. Worker participation can refer either to direct or indirect participation

Workers' Education Methods and Techniques for Rural Workers and Their Organisations: Summary of Views Expressed

Science.gov (United States)

Labour Education, 1975

1975-01-01

Several issues concerning rural workers' organizations and workers' education are discussed: motivation for self-organization, workers' education needs of rural workers, workers' education methods and techniques, training institutions and training personnel, financial resources, and the role of the International Labor Organization workers'…

Social modulation of stress reactivity and learning in young worker honey bees.

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Elodie Urlacher

Full Text Available Alarm pheromone and its major component isopentylacetate induce stress-like responses in forager honey bees, impairing their ability to associate odors with a food reward. We investigated whether isopentylacetate exposure decreases appetitive learning also in young worker bees. While isopentylacetate-induced learning deficits were observed in guards and foragers collected from a queen-right colony, learning impairments resulting from exposure to this pheromone could not be detected in bees cleaning cells. As cell cleaners are generally among the youngest workers in the colony, effects of isopentylacetate on learning behavior were examined further using bees of known age. Adult workers were maintained under laboratory conditions from the time of adult emergence. Fifty percent of the bees were exposed to queen mandibular pheromone during this period, whereas control bees were not exposed to this pheromone. Isopentylacetate-induced learning impairments were apparent in young (less than one week old controls, but not in bees of the same age exposed to queen mandibular pheromone. This study reveals young worker bees can exhibit a stress-like response to alarm pheromone, but isopentylacetate-induced learning impairments in young bees are suppressed by queen mandibular pheromone. While isopentylacetate exposure reduced responses during associative learning (acquisition, it did not affect one-hour memory retrieval.

Social Modulation of Stress Reactivity and Learning in Young Worker Honey Bees

Science.gov (United States)

Mercer, Alison R.

2014-01-01

Alarm pheromone and its major component isopentylacetate induce stress-like responses in forager honey bees, impairing their ability to associate odors with a food reward. We investigated whether isopentylacetate exposure decreases appetitive learning also in young worker bees. While isopentylacetate-induced learning deficits were observed in guards and foragers collected from a queen-right colony, learning impairments resulting from exposure to this pheromone could not be detected in bees cleaning cells. As cell cleaners are generally among the youngest workers in the colony, effects of isopentylacetate on learning behavior were examined further using bees of known age. Adult workers were maintained under laboratory conditions from the time of adult emergence. Fifty percent of the bees were exposed to queen mandibular pheromone during this period, whereas control bees were not exposed to this pheromone. Isopentylacetate-induced learning impairments were apparent in young (less than one week old) controls, but not in bees of the same age exposed to queen mandibular pheromone. This study reveals young worker bees can exhibit a stress-like response to alarm pheromone, but isopentylacetate-induced learning impairments in young bees are suppressed by queen mandibular pheromone. While isopentylacetate exposure reduced responses during associative learning (acquisition), it did not affect one-hour memory retrieval. PMID:25470128

Changes in the Gene Expression Profiles of the Hypopharyngeal Gland of Worker Honeybees in Association with Worker Behavior and Hormonal Factors.

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Takayuki Ueno

Full Text Available The hypopharyngeal glands (HPGs of worker honeybees undergo physiological changes along with the age-dependent role change from nursing to foraging: nurse bee HPGs secrete mainly major royal jelly proteins, whereas forager HPGs secrete mainly α-glucosidase III, which converts the sucrose in the nectar into glucose and fructose. We previously identified two other genes, Apis mellifera buffy (Ambuffy and Apis mellifera matrix metalloproteinase 1 (AmMMP1, with enriched expression in nurse bee and forager HPGs, respectively. In the present study, to clarify the molecular mechanisms that coordinate HPG physiology with worker behavior, we first analyzed whether Ambuffy, AmMMP1, mrjp2 (a gene encoding one of major royal jelly protein isoforms, and Hbg3 (a gene encoding α-glucosidase III expression, is associated with worker behavior in 'single-cohort colonies' where workers of almost the same age perform different tasks. Expression of these genes correlated with the worker's role, while controlling for age, indicating their regulation associated with the worker's behavior. Associated gene expression suggested the possible involvement of some hormonal factors in its regulation. We therefore examined the relationship between ecdysone- and juvenile hormone (JH-signaling, and the expression profiles of these 'indicator' genes (nurse bee HPG-selective genes: mrjp2 and Ambuffy, and forager HPG-selective genes: Hbg3 and AmMMP1. Expression of both ecdysone-regulated genes (ecdysone receptor, mushroom body large type Kenyon cell specific protein-1, and E74 and JH-regulated genes (Methoprene tolerant and Krüppel homolog 1 was higher in the forager HPGs than in the nurse bee HPGs, suggesting the possible roles of ecdysone- and JH-regulated genes in worker HPGs. Furthermore, 20-hydroxyecdysone-treatment repressed both nurse bee- and forager-selective gene expression, whereas methoprene-treatment enhanced the expression of forager-selective genes and repressed

Characteristic of the immunological state of Chernobyl accident clean-up workers in a late period after the accident

International Nuclear Information System (INIS)

Kurjane, N.; Zvagule, T.; Curbakova, E.; Bruvere, R.; Romanova, T.; Sitova, O; Hagina, E.; Socnevs, A.

2001-01-01

No differences in the number of immunologically competent cells and other immunological variables were found among the clean-up workers, depending on the time they were in Chernobyl. However, a statistically significant reduction in the number of CD3+, CD4+, CD16+ and CD19+, decrease in the levels of IgG and suppression of APH and the phagocytic activity of neutrophils with a simultaneous increase in the levels of IgA and C3d was found in all clean-up workers when compared to controls. In a small group of clean-up workers, the levels of some plasma cytokines were detected. A statistically significant increase in IL-6 levels was found in the clean-up workers when compared to controls. The irradiation received by the Chernobyl accident clean-up workers was large enough to cause disturbances in the function of cells and organ systems through immune system disorders with a resultant weakening of the body response and adaptation mechanisms. (authors)

Semi-permeable species boundaries in the coral genus Madracis: introgression in a brooding coral system.

Science.gov (United States)

Frade, P R; Reyes-Nivia, M C; Faria, J; Kaandorp, J A; Luttikhuizen, P C; Bak, R P M

2010-12-01

Introgressive hybridization is described in several phylogenetic studies of mass-spawning corals. However, the prevalence of this process among brooding coral species is unclear. We used a mitochondrial (mtDNA: nad5) and two nuclear (nDNA: ATPSα and SRP54) intron markers to explore species barriers in the coral genus Madracis and address the role of hybridization in brooding systems. Specimens of six Caribbean Madracis morphospecies were collected from 5 to 60 m depth at Buoy One, Curaçao, supplemented by samples from Aruba, Trinidad & Tobago and Bermuda. Polymerase chain reaction and denaturing gradient gel electrophoresis were coupled to detect distinct alleles within single colonies. The recurrent nDNA phylogenetic non-monophyly among taxa is only challenged by Madracis senaria, the single monophyletic species within the genus. nDNA AMOVAs indicated overall statistical divergence (0.1% significance level) among species but pairwise comparisons of genetic differentiation revealed some gene exchange between Madracis taxa. mtDNA sequences clustered in two main groups representing typical shallow and deep water Madracis species. Madracis pharensis shallow and deep colonies (with threshold at about 23-24 m) clustered in different mtDNA branches, together with their depth-sympatric congenerics. This divergence was repeated for the nDNA (ATPSα) suggestive of distinct M. pharensis depth populations. These matched the vertical distribution of the dinoflagellate symbionts hosted by M. pharensis, with Symbiodinium ITS2 type B7 in the shallows but type B15 in the deep habitats, suggesting symbiont-related disruptive selection. Recurrent non-monophyly of Madracis taxa and high levels of shared polymorphism reflected in ambiguous phylogenetic networks indicate that hybridization is likely to have played a role in the evolution of the genus. Using coalescent forward-in-time simulations, lineage sorting alone was rejected as an explanation to the SRP54 genetic variation

Dermatologic Diseases in Silk Workers

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J S Pasricha

1985-01-01

Full Text Available A survey of 112 workers of a silk facory near Bangalore, for dermatologic diseases revealed (1 a characteristic wearing off of the medial halves of the distal free edges of the finger nail plates in 10 of the 15 cocoonsorters, (2 maceration of the palms in 58 workers of the boiling and reeling section, and (3 pitted keratolysis of the palms, in 42 workers, also from the boiling and reeling section. There was no clinical evidence of contact dermatitis, and patch tests with the silk thread from the cocoons in 25 workers showed a very mild reaction in 2 workers and a doubtful reaction in another two. In addition, one worker from the skeining section had crisscross superficial fissures on the finger tips caused by friction, two workers had paronychia ′of the fingers and four workers had dermatophytFNx01t fingers webs. As in the previous survey, these workers also had a high incidence of ichthyosis (92 workers and hyperketatosis of the palms (62 workers and soles (110 workers.

Late winter feeding stimulates rapid spring development of carniolan honey bee colonies (Apis mellifera carnica

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Zlatko Puškadija

2017-01-01

Full Text Available Unfavourable weather conditions after the queen starts with intensive oviposition during early spring may cause an imbalance in the division of tasks among worker bees in the bee colony. This can lead to slow spring development and poor exploitation of the main spring nectar flows. In order to accelerate the spring development, it is necessary, as a technological measure, to feed supplemental candy to bee colonies. In this research, the necessity of supplemental feeding, as well as the composition of candy (pollen and protein substitute were analysed. Three groups of ten bee colonies each were formed - the control, unfed group, pollen candy fed and protein substitute candy fed. In the period from 22/02/2016 and 04/04/2016 three control measurements were performed during which the number of bees, the number of brood cells and weight of the bee colonies were determined. The research has shown that supplemental feeding of the bee colony in late winter in order to encourage the rapid spring development is justified. Namely, at the final measurements in April, the results showed differences between groups. The treated colonies had higher net hive weight, a greater number of bees and statistically significantly more brood cells. The results of this study confirm that the technological measure of supplemental feeding in late winter should be performed on all commercial apiaries for the production of honey, pollen, royal jelly, queen bees and bee venom.

Study of chromosome aberrations on the workers occupationally exposed to thorium and rare earth mixed dust

International Nuclear Information System (INIS)

Zhang Wei; Wang Chunyan; Lv Huiming; Zhang Cuilan; Hao Shuxia; Su Xu; Jia Kejun; Liu Yufei

2008-01-01

Objective: To study the effect of thorium and rare earth mixed dust on chromosome aberrations in the lymphocytes of occupational exposed workers. Methods: Analyses of unstable chromosome aberrations on 53 occupational exposed workers and 58 control workers were carried out by the conventional Giemsa staining method. Fluorescence in situ hybridization method was performed to analyze the chromosome stable aberrations on 10 occupational exposed workers and l0 control workers. Results: The frequencies of chromosomal aberration cells, dicentrics plus rings, total aberrations in exposed workers were significantly higher than those in controls. No significant difference was found in the frequency of acentric aberrations between exposed and non-exposed workers. No significant difference was found in the frequency of translocations between exposed and non-exposed workers. Conclusions: Chronically occupational exposure to thorium and rare earth mixed dust can increase the induction of unstable chromosome aberration, but the increase of stable chromosome aberrations (translocation) can not be observed. (authors)

Intracellular free calcium concentration and calcium transport in human erythrocytes of lead-exposed workers

International Nuclear Information System (INIS)

Quintanar-Escorza, M.A.; Gonzalez-Martinez, M.T.; Navarro, L.; Maldonado, M.; Arevalo, B.; Calderon-Salinas, J.V.

2007-01-01

Erythrocytes are the route of lead distribution to organs and tissues. The effect of lead on calcium homeostasis in human erythrocytes and other excitable cells is not known. In the present work we studied the effect of lead intoxication on the uptake and efflux (measured as (Ca 2+ -Mg 2+ )-ATPase activity) of calcium were studied in erythrocytes obtained from lead-exposed workers. Blood samples were taken from 15 workers exposed to lead (blood lead concentration 74.4 ± 21.9 μg/dl) and 15 non-exposed workers (9.9 ± 2 μg/dl). In erythrocytes of lead-exposed workers, the intracellular free calcium was 79 ± 13 nM, a significantly higher concentration (ANOVA, P 2+ -Mg 2+ )-ATPase activity. Lipid peroxidation was 1.7-fold higher in erythrocytes of lead-exposed workers as compared with control. The alteration on calcium equilibrium in erythrocytes is discussed in light of the toxicological effects in lead-exposed workers

Association of psychological stress response of fatigue with white blood cell count in male daytime workers.

Science.gov (United States)

Nishitani, Naoko; Sakakibara, Hisataka

2014-01-01

Relationships between work-related psychological and physical stress responses and counts of white blood cells (WBCs), neutrophils, and lymphocytes were investigated in 101 daytime workers. Counts of WBCs and neutrophils were positively associated with smoking and inversely correlated with high density lipoprotein (HDL)-cholesterol levels. Additionally, general fatigue score as measured by the profile of mood state was positively correlated with WBC and neutrophil counts whereas lymphocyte counts was not significantly associated with fatigue score. Multiple regression analysis showed that WBC count was significantly related to general fatigue, age, and HDL-cholesterol levels. Neutrophil count was significantly related to HDL-cholesterol levels and fatigue score. Among various psychological stress response variables, general fatigue may be a key determinant of low-grade inflammation as represented by increases of WBC and neutrophil counts.

Cleaner mites: sanitary mutualism in the miniature ecosystem of neotropical bee nests.

Science.gov (United States)

Biani, Natalia B; Mueller, Ulrich G; Wcislo, William T

2009-06-01

Cleaning symbioses represent classic models of mutualism, and some bee mites are thought to perform cleaning services for their hosts in exchange for suitable environments for reproduction and dispersal. These mutual benefits, however, have not been rigorously demonstrated. We tested the sanitary role of bee mites by correlating mite loads with fungal contamination in natural nests of Megalopta genalis and Megalopta ecuadoria and by experimentally manipulating mite loads in artificial cells with developing brood. Field observations revealed significant correlations between the presence of mites and the absence of fungi inside the brood cells, as well as between the absence of mites and increased bee mortality. Likewise, experimental brood cells with mites have fewer fungal colonies than do cells without mites. Field observations and experimental manipulations, therefore, provide clear evidence of the sanitary effect of mites in nests of Megalopta bees. This bee-mite association constitutes one of the few examples of terrestrial cleaning mutualisms.

Non-occupational physical activity levels of shift workers compared with non-shift workers

Science.gov (United States)

Loef, Bette; Hulsegge, Gerben; Wendel-Vos, G C Wanda; Verschuren, W M Monique; Bakker, Marije F; van der Beek, Allard J; Proper, Karin I

2017-01-01

Objectives Lack of physical activity (PA) has been hypothesised as an underlying mechanism in the adverse health effects of shift work. Therefore, our aim was to compare non-occupational PA levels between shift workers and non-shift workers. Furthermore, exposure–response relationships for frequency of night shifts and years of shift work regarding non-occupational PA levels were studied. Methods Data of 5980 non-shift workers and 532 shift workers from the European Prospective Investigation into Cancer and Nutrition-Netherlands (EPIC-NL) were used in these cross-sectional analyses. Time spent (hours/week) in different PA types (walking/cycling/exercise/chores) and intensities (moderate/vigorous) were calculated based on self-reported PA. Furthermore, sports were operationalised as: playing sports (no/yes), individual versus non-individual sports, and non-vigorous-intensity versus vigorous-intensity sports. PA levels were compared between shift workers and non-shift workers using Generalized Estimating Equations and logistic regression. Results Shift workers reported spending more time walking than non-shift workers (B=2.3 (95% CI 1.2 to 3.4)), but shift work was not associated with other PA types and any of the sports activities. Shift workers who worked 1–4 night shifts/month (B=2.4 (95% CI 0.6 to 4.3)) and ≥5 night shifts/month (B=3.7 (95% CI 1.8 to 5.6)) spent more time walking than non-shift workers. No exposure–response relationships were found between years of shift work and PA levels. Conclusions Shift workers spent more time walking than non-shift workers, but we observed no differences in other non-occupational PA levels. To better understand if and how PA plays a role in the negative health consequences of shift work, our findings need to be confirmed in future studies. PMID:27872151

Infestação pelo Ácaro Varroa destructor (Anderson & Trueman (Mesostigmata: Varroidae em Operárias Adultas e em Células de Cria de Abelhas Africanizadas Apis mellifera Linnaeus (Hymenoptera: Apidae na Região de Franca-SP

Directory of Open Access Journals (Sweden)

Aline Turcatto

2012-12-01

Abstract. The mite Varroa destructor (Anderson & Trueman, has been, until now, one of the pest that causes more damage to the beekeeping worldwide, alone or associated with another bee diseases. Several factors affects the variation of the indexes of infestation and reproduction, such as climate, bee breed, development time, hygienic behavior; being that temperature is a environmental variable that acts on the variation of these indexes: the infestation increases in the colder months and decrease in warmer months, so in the months of autumn and winter occurs the biggest infestation by varroa in the beehives. Were evaluated the indexes of infestation by V. destructor on adult worker and brood cells to ascertain how these indexes rates, in months of autumn, in an africanized bees apiary located in region of Cerrado, surrounded by plantations of sugar cane, with a tropical climate and food in nature. The sample was collected in two years, in the months of May and June 2005 and April and June 2007 in the Experimental Apiary of Franca University-UNIFRAN, located in the municipality of Restiga-SP. The medium indexes of infestation in broods were higher in May/2005 (12.44% than June/2005 (7.78%, were also higher in April/2007 (3% than in June/2007 (0%; all the differences weren’t statistically significant. The medium indexes of infestation in adult workers were lesser in May/2005 (0.95% than June/2005 (1.90% and lesser in April/2007 (0.90% than in June/2007 (4.43%; the difference observed in 2005 was not statistically significant, unlike that observed in 2007 (P=0.031.

Mortality among retired fur workers. Dyers, dressers (tanners) and service workers

Energy Technology Data Exchange (ETDEWEB)

Sweeney, M.H.; Walrath, J.; Waxweiler, R.J.

1985-08-01

A retrospective cohort mortality study was conducted on 807 fur dyers, fur dressers (tanners), and fur service workers who were pensioned between 1952 and 1977 by the Fur, Leather and Machine Workers Union of New York City. Workplace exposures of fur workers varied with job category. Dyers were exposed to oxidative dyes used in commercial hair dyes; dressers and service workers were exposed to tanning chemicals. In a comparison with the New York City population, no significant increases in mortality were observed among the fur dyers. Among fur dressers, mortality from all malignant neoplasms and lung cancer was significantly elevated, as was mortality from cardiovascular disease among fur service workers. When examined by ethnic origin, the elevated SMR values and directly age-adjusted rate ratios suggested that foreign-born fur dressers and eastern European-born fur workers experienced the highest risks for lung and colorectal cancers, respectively. These data support previous findings of increased mortality from colorectal cancer in the foreign-born population of the United States and suggest a possible occupational etiology for the observed lung cancer excess.

Occupational Stress Among Home Healthcare Workers: Integrating Worker and Agency-Level Factors.

Science.gov (United States)

Zoeckler, Jeanette M

2018-02-01

Home healthcare work is physically and emotionally exhausting. In addition, home healthcare workers frequently work under precarious work arrangements for low wages and in poor work conditions. Little is known about how sources of job strain for home healthcare workers might be reduced. This research examines the occupational stressors among paid home care workers by analyzing home healthcare agency characteristics and individual home healthcare workers' experiences in upstate New York agencies (n = 9). The study augments existing theoretical models and describes new sources of stress arising from the nature of agency-based caregiving. Results feature the analysis of both agency executives' (n = 20) and home healthcare workers' narratives (n = 25) to make the agency's inner workings more transparent. Agency structures and culture are implicated in the lack of progress to address home care workers' health problems. Policy change should focus on compensation, healthier work conditions, and training requirements.

Genetic and Biochemical Diversity of Paenibacillus larvae Isolated from Tunisian Infected Honey Bee Broods

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Chadlia Hamdi

2013-01-01

Full Text Available Paenibacillus larvae is the causative agent of American foulbrood (AFB, a virulent disease of honeybee (Apis mellifera larvae. In Tunisia, AFB has been detected in many beekeeping areas, where it causes important economic losses, but nothing is known about the diversity of the causing agent. Seventy-five isolates of P. larvae, identified by biochemical tests and 16S rRNA gene sequencing, were obtained from fifteen contaminated broods showing typical AFB symptoms, collected in different locations in the northern part of the country. Using BOX-PCR, a distinct profile of P. larvae with respect to related Paenibacillus species was detected which may be useful for its identification. Some P. larvae-specific bands represented novel potential molecular markers for the species. BOX-PCR fingerprints indicated a relatively high intraspecific diversity among the isolates not described previously with several molecular polymorphisms identifying six genotypes on polyacrylamide gel. Polymorphisms were also detected in several biochemical characters (indol production, nitrate reduction, and methyl red and oxidase tests. Contrary to the relatively high intraspecies molecular and phenotypic diversity, the in vivo virulence of three selected P. larvae genotypes did not differ significantly, suggesting that the genotypic/phenotypic differences are neutral or related to ecological aspects other than virulence.

Advanced worker protection system

International Nuclear Information System (INIS)

Caldwell, B.; Duncan, P.; Myers, J.

1995-01-01

The Department of Energy (DOE) is in the process of defining the magnitude and diversity of Decontamination and Decommissioning (D ampersand D) obligations at its numerous sites. The DOE believes that existing technologies are inadequate to solve many challenging problems such as how to decontaminate structures and equipment cost effectively, what to do with materials and wastes generated, and how to adequately protect workers and the environment. Preliminary estimates show a tremendous need for effective use of resources over a relatively long period (over 30 years). Several technologies are being investigated which can potentially reduce D ampersand D costs while providing appropriate protection to DOE workers. The DOE recognizes that traditional methods used by the EPA in hazardous waste site clean up activities are insufficient to provide the needed protection and worker productivity demanded by DOE D ampersand D programs. As a consequence, new clothing and equipment which can adequately protect workers while providing increases in worker productivity are being sought for implementation at DOE sites. This project will result in the development of an Advanced Worker Protection System (AWPS). The AWPS will be built around a life support backpack that uses liquid air to provide cooling as well as breathing gas to the worker. The backpack will be combined with advanced protective garments, advanced liquid cooling garment, respirator, communications, and support equipment to provide improved worker protection, simplified system maintenance, and dramatically improve worker productivity through longer duration work cycles. Phase I of the project has resulted in a full scale prototype Advanced Worker Protection Ensemble (AWPE, everything the worker will wear), with sub-scale support equipment, suitable for integrated testing and preliminary evaluation. Phase II will culminate in a full scale, certified, pre-production AWPS and a site demonstration

Advanced worker protection system

Energy Technology Data Exchange (ETDEWEB)

Caldwell, B.; Duncan, P.; Myers, J.

1995-12-01

The Department of Energy (DOE) is in the process of defining the magnitude and diversity of Decontamination and Decommissioning (D&D) obligations at its numerous sites. The DOE believes that existing technologies are inadequate to solve many challenging problems such as how to decontaminate structures and equipment cost effectively, what to do with materials and wastes generated, and how to adequately protect workers and the environment. Preliminary estimates show a tremendous need for effective use of resources over a relatively long period (over 30 years). Several technologies are being investigated which can potentially reduce D&D costs while providing appropriate protection to DOE workers. The DOE recognizes that traditional methods used by the EPA in hazardous waste site clean up activities are insufficient to provide the needed protection and worker productivity demanded by DOE D&D programs. As a consequence, new clothing and equipment which can adequately protect workers while providing increases in worker productivity are being sought for implementation at DOE sites. This project will result in the development of an Advanced Worker Protection System (AWPS). The AWPS will be built around a life support backpack that uses liquid air to provide cooling as well as breathing gas to the worker. The backpack will be combined with advanced protective garments, advanced liquid cooling garment, respirator, communications, and support equipment to provide improved worker protection, simplified system maintenance, and dramatically improve worker productivity through longer duration work cycles. Phase I of the project has resulted in a full scale prototype Advanced Worker Protection Ensemble (AWPE, everything the worker will wear), with sub-scale support equipment, suitable for integrated testing and preliminary evaluation. Phase II will culminate in a full scale, certified, pre-production AWPS and a site demonstration.

Analysis of chromosomal aberrations, micronuclei and hematological disorders among workers of wireless communication instruments and cell phone (Mobile) users

International Nuclear Information System (INIS)

Eldawy, H.A.; Khattab, F.I.; Hassan, N.H.A.; Amin, Y.M.; Mahmoud, M.M.A.

2003-01-01

This study was carried out to investigate the hazardous effect of electromagnetic radiation (EMR) such as chromosomal aberration, disturbed micronucleus formation and hematological disorders that may detected among workers of wireless communication instruments and mobile phone users. Seven individuals ( 3 males and 4 females) of a central workers in the microwave unit of the wireless station and 7 users of Mobil phone (4 males and 3 females ) were volunteered to give blood samples. Chromosomes and micronucleus were prepared for cytogenetic analysis as well as blood film for differential count. The results obtained in the microwave group indicated that, the total summation of all types of aberrations (chromosomes and chromatid aberrations) had a frequency of 6. 14% for the exposed group, whereas, the frequency in the control group amounted to 1.57%. In Mobil phone users, the total summation of all types of aberrations(chromosome and chromatid aberrations) had a frequency of 4.43% for the exposed group and 1.71% for the control group. The incidence of the total number of micronuclei in the exposed microwave group was increased 4.3 folds as compared with those of the control group The incidence of the total number of micronuclei in the exposed mobile phone group was increased 2 fold as compared with those in the control group. On the other hand, normal ranges of total white blood cells counts were determined for mobile phone users but abnormalities in the differential counts of the different types of the white blood cells such as neutropenia, eosinophilia and lymphocytosis were observed in the individuals number 1,2,3,7 in microwave group

Productivity Gains from Worker Mobility and their Distribution between Workers and Firms

NARCIS (Netherlands)

A. Stoyanov (Andrey); N.V. Zubanov (Nick)

2012-01-01

textabstractUsing data from the universe of Danish manufacturing firms and workers over the period 1995-2007, we estimate output gains linked to productivity spillovers through worker mobility, and calculate the shares in these gains accrued to firms, to the workers who bring spillovers, and to the

Mortality among retired fur workers. Dyers, dressers (tanners) and service workers.

Science.gov (United States)

Sweeney, M H; Walrath, J; Waxweiler, R J

1985-08-01

A retrospective cohort mortality study was conducted on 807 fur dyers, fur dressers (tanners), and fur service workers who were pensioned between 1952 and 1977 by the Fur, Leather and Machine Workers Union of New York City. Workplace exposures of fur workers varied with job category. Dyers were exposed to oxidative dyes used in commercial hair dyes; dressers and service workers were exposed to tanning chemicals. In a comparison with the New York City population, no significant increases in mortality were observed among the fur dyers. Among fur dressers, mortality from all malignant neoplasms [standardized mortality ratio (SMR) 151] and lung cancer (SMR 232) was significantly elevated, as was mortality from cardiovascular disease (SMR 126) among fur service workers. When examined by ethnic origin, the elevated SMR values and directly age-adjusted rate ratios suggested that foreign-born fur dressers and eastern European-born fur workers experienced the highest risks for lung and colorectal cancers, respectively. These data support previous findings of increased mortality from colorectal cancer in the foreign-born population of the United States and suggest a possible occupational etiology for the observed lung cancer excess.

Non-occupational physical activity levels of shift workers compared with non-shift workers.

Science.gov (United States)

Loef, Bette; Hulsegge, Gerben; Wendel-Vos, G C Wanda; Verschuren, W M Monique; Vermeulen, Roel C H; Bakker, Marije F; van der Beek, Allard J; Proper, Karin I

2017-05-01

Lack of physical activity (PA) has been hypothesised as an underlying mechanism in the adverse health effects of shift work. Therefore, our aim was to compare non-occupational PA levels between shift workers and non-shift workers. Furthermore, exposure-response relationships for frequency of night shifts and years of shift work regarding non-occupational PA levels were studied. Data of 5980 non-shift workers and 532 shift workers from the European Prospective Investigation into Cancer and Nutrition-Netherlands (EPIC-NL) were used in these cross-sectional analyses. Time spent (hours/week) in different PA types (walking/cycling/exercise/chores) and intensities (moderate/vigorous) were calculated based on self-reported PA. Furthermore, sports were operationalised as: playing sports (no/yes), individual versus non-individual sports, and non-vigorous-intensity versus vigorous-intensity sports. PA levels were compared between shift workers and non-shift workers using Generalized Estimating Equations and logistic regression. Shift workers reported spending more time walking than non-shift workers (B=2.3 (95% CI 1.2 to 3.4)), but shift work was not associated with other PA types and any of the sports activities. Shift workers who worked 1-4 night shifts/month (B=2.4 (95% CI 0.6 to 4.3)) and ≥5 night shifts/month (B=3.7 (95% CI 1.8 to 5.6)) spent more time walking than non-shift workers. No exposure-response relationships were found between years of shift work and PA levels. Shift workers spent more time walking than non-shift workers, but we observed no differences in other non-occupational PA levels. To better understand if and how PA plays a role in the negative health consequences of shift work, our findings need to be confirmed in future studies. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Effect of egg storage duration and brooding temperatures on chick growth, intestine morphology and nutrient transporters.

Science.gov (United States)

Yalcin, S; Gursel, I; Bilgen, G; Horuluoglu, B H; Gucluer, G; Izzetoglu, G T

2017-10-01

The effects of egg storage duration (ESD) and brooding temperature (BT) on BW, intestine development and nutrient transporters of broiler chicks were investigated. A total of 396 chicks obtained from eggs stored at 18°C for 3 days (ESD3-18°C) or at 14°C for 14 days (ESD14-14°C) before incubation were exposed to three BTs. Temperatures were initially set at 32°C, 34°C and 30°C for control (BT-Cont), high (BT-High) and low (BT-Low) BTs, respectively. Brooding temperatures were decreased by 2°C each at days 2, 7, 14 and 21. Body weight was measured at the day of hatch, 2, 7, 14, 21, 28 and 42. Cloacal temperatures of broilers were recorded from 1 to 14 days. Intestinal morphology and gene expression levels of H+-dependent peptide transporter (PepT1) and Na-dependent glucose (SGLT1) were evaluated on the day of hatch and 14. Cloacal temperatures of chicks were affected by BTs from days 1 to 8, being the lowest for BT-Low chicks. BT-High resulted in the heaviest BWs at 7 days, especially for ESD14-14°C chicks. This result was consistent with longer villus and larger villus area of ESD14-14°C chicks at BT-High conditions. From 14 days to slaughter age, BT had no effect on broiler weight. ESD3-18°C chicks were heavier than ESD14-14°C chicks up to 28 days. The PepT1 and SGLT1 expression levels were significantly higher in ESD3-18°C chicks than ESD14-14°C on the day of hatch. There was significant egg storage by BT interaction for PepT1 and SGLT1 transporters at day 14. ESD14-14°C chicks had significantly higher expression of PepT1 and SGLT1 at BT-Low than those at BT-Cont. ESD14-14°C chicks upregulated PepT1 gene expression 1.15 and 1.57-fold at BT-High and BT-Low, respectively, compared with BT-Cont, whereas PepT1 expression was downregulated 0.67 and 0.62-fold in ESD3-18°C chicks at BT-High and BT-Low. These results indicated that pre-incubation egg storage conditions and BTs affected intestine morphology and PepT1 and SGLT1 nutrient transporters

Towards improving workers' health by matching work and workers

NARCIS (Netherlands)

Zoer, I.

2014-01-01

From an occupational health perspective, the match between work and workers was the central topic in this thesis. The term ‘work’ was used to encompass a combination of physical, mental and psychosocial work demands. The term ‘workers’ represents the resources of workers, in terms of physical,

Effects of clothianidin on Bombus impatiens (Hymenoptera: Apidae) colony health and foraging ability.

Science.gov (United States)

Franklin, Michelle T; Winston, Mark L; Morandin, Lora A

2004-04-01

We conducted laboratory experiments to investigate the lethal and sublethal effects of clothianidin on bumble bee, Bombus impatiens Cresson, colony health and foraging ability. Bumble bee colonies were exposed to 6 ppb clothianidin, representing the highest residue levels found in field studies on pollen, and a higher dose of 36 ppb clothianidin in pollen. Clothianidin did not effect pollen consumption, newly emerged worker weights, amount of brood or the number of workers, males, and queens at either dose. The foraging ability of worker bees tested on an artificial array of complex flowers also did not differ among treatments. These results suggest that clothianidin residues found in seed-treated canola and possibly other crops will not adversely affect the health of bumble bee colonies or the foraging ability of workers.

Genotoxic Effects Due to Exposure to Chromium and Nickel Among Electroplating Workers.

Science.gov (United States)

El Safty, Amal Mohamed Kamal; Samir, Aisha Mohamed; Mekkawy, Mona Kamal; Fouad, Marwa Mohamed

Using chromium and nickel for electroplating is important in many industries. This process induces variable adverse health effects among exposed workers. The aim of this study is to detect the genotoxic effects of combined exposure to chromium and nickel among electroplating workers. This study was conducted on 41 male workers occupationally exposed to chromium and nickel in the electroplating section of a factory compared to 41 male nonexposed individuals, where full history and clinical examination were performed. Laboratory investigations included measurement of serum chromium, nickel, 8-hydroxydeoxyguanosine (8-OHdG), and micronuclei were measured in buccal cells. In exposed workers, serum chromium ranged from 0.09 to 7.20 µg/L, serum nickel ranged from 1.20 to 28.00 µg/L, serum 8-OHdG ranged from 1.09 to12.60 ng/mL, and these results were statistically significantly increased compared to nonexposed group ( P electroplating industry are at risk of significant cytogenetic damage.

Effects of ovule and seed abortion on brood size and fruit costs in the leguminous shrub Caesalpinia gilliesii (Wall. ex Hook. D. Dietr

Directory of Open Access Journals (Sweden)

Ana Calviño

2014-03-01

Full Text Available For several plant species, brood size results from the abortion of ovules and seeds. However, these processes have rarely been studied together in wild plants. In some of the leguminous species studied, seed abortion has been found to depend on pollen quality and on the position of the ovule or fruit. The direct consequence for the mother plant is that fruit costs increase as the seed:ovule ratio decreases. However, because ovule abortion occurs earlier than does seed abortion, the former can reduce the biomass invested per seed (i.e., fruit costs more efficiently than does the latter. Here, the frequencies of aborted ovules and seeds were analyzed in relation to the type of pollination treatment (open pollination vs. hand cross-pollination and ovule/fruit position within pods of the leguminous shrub Caesalpinia gilliesii. The influence of ovule and seed abortion on fruit costs was analyzed by comparing the pericarp mass per seed between fruits with different frequencies of aborted ovules and seeds. The rate of ovule abortion was similar between hand cross-pollinated and open-pollinated fruits but was higher than that of seed abortion in one- and two-seeded fruits, as well as in those at stylar positions and in distal fruits. Hand cross-pollination reduced seed abortion but did not increase the seed:ovule ratio. In addition, fruits that aborted ovules were found to be less costly than were those that aborted seeds. From the mother plant perspective, these results indicate that ovule abortion is a more efficient mechanism of reducing fruit costs than is seed abortion, because fertilization opportunities decrease with position, and show that brood size is significantly influenced by the fate of the ovule at the pre-zygotic stage.

Eryptosis in lead-exposed workers

International Nuclear Information System (INIS)

Aguilar-Dorado, Itzel-Citlalli; Hernández, Gerardo; Quintanar-Escorza, Martha-Angelica; Maldonado-Vega, María; Rosas-Flores, Margarita; Calderón-Salinas, José-Víctor

2014-01-01

Eryptosis is a physiological phenomenon in which old and damaged erythrocytes are removed from circulation. Erythrocytes incubated with lead have exhibited major eryptosis. In the present work we found evidence of high levels of eryptosis in lead exposed workers possibly via oxidation. Blood samples were taken from 40 male workers exposed to lead (mean blood lead concentration 64.8 μg/dl) and non-exposed workers (4.2 μg/dl). The exposure to lead produced an intoxication characterized by 88.3% less δ-aminolevulinic acid dehydratase (δALAD) activity in lead exposed workers with respect to non-lead exposed workers. An increment of oxidation in lead exposed workers was characterized by 2.4 times higher thiobarbituric acid-reactive substance (TBARS) concentration and 32.8% lower reduced/oxidized glutathione (GSH/GSSG) ratio. Oxidative stress in erythrocytes of lead exposed workers is expressed in 192% higher free calcium concentration [Ca 2+ ] i and 1.6 times higher μ-calpain activity with respect to non-lead exposed workers. The adenosine triphosphate (ATP) concentration was not significantly different between the two worker groups. No externalization of phosphatidylserine (PS) was found in non-lead exposed workers (< 0.1%), but lead exposed workers showed 2.82% externalization. Lead intoxication induces eryptosis possibly through a molecular pathway that includes oxidation, depletion of reduced glutathione (GSH), increment of [Ca 2+ ], μ-calpain activation and externalization of PS in erythrocytes. Identifying molecular signals that induce eryptosis in lead intoxication is necessary to understand its physiopathology and chronic complications. - Graphical abstract: Fig. 1. (A) Blood lead concentration (PbB) and (B) phosphatidylserine externalization on erythrocyte membranes of non-lead exposed (□) and lead exposed workers (■). Values are mean ± SD. *Significantly different (P < 0.001). - Highlights: • Erythrocytes of lead exposed workers showed higher PS

Eryptosis in lead-exposed workers

Energy Technology Data Exchange (ETDEWEB)

Aguilar-Dorado, Itzel-Citlalli [Biochemistry Department, Centro de Investigación y Estudios Avanzados IPN, México, DF (Mexico); Hernández, Gerardo [Section of Methodology of Science, Centro de Investigación y Estudios Avanzados IPN, México, DF (Mexico); Quintanar-Escorza, Martha-Angelica [Faculty of Medicine, UJED, Durango, DGO (Mexico); Maldonado-Vega, María [CIATEC, León, GTO (Mexico); Rosas-Flores, Margarita [Biochemistry Department, Centro de Investigación y Estudios Avanzados IPN, México, DF (Mexico); Calderón-Salinas, José-Víctor, E-mail: jcalder@cinvestav.mx [Biochemistry Department, Centro de Investigación y Estudios Avanzados IPN, México, DF (Mexico)

2014-12-01

Eryptosis is a physiological phenomenon in which old and damaged erythrocytes are removed from circulation. Erythrocytes incubated with lead have exhibited major eryptosis. In the present work we found evidence of high levels of eryptosis in lead exposed workers possibly via oxidation. Blood samples were taken from 40 male workers exposed to lead (mean blood lead concentration 64.8 μg/dl) and non-exposed workers (4.2 μg/dl). The exposure to lead produced an intoxication characterized by 88.3% less δ-aminolevulinic acid dehydratase (δALAD) activity in lead exposed workers with respect to non-lead exposed workers. An increment of oxidation in lead exposed workers was characterized by 2.4 times higher thiobarbituric acid-reactive substance (TBARS) concentration and 32.8% lower reduced/oxidized glutathione (GSH/GSSG) ratio. Oxidative stress in erythrocytes of lead exposed workers is expressed in 192% higher free calcium concentration [Ca{sup 2+}]{sub i} and 1.6 times higher μ-calpain activity with respect to non-lead exposed workers. The adenosine triphosphate (ATP) concentration was not significantly different between the two worker groups. No externalization of phosphatidylserine (PS) was found in non-lead exposed workers (< 0.1%), but lead exposed workers showed 2.82% externalization. Lead intoxication induces eryptosis possibly through a molecular pathway that includes oxidation, depletion of reduced glutathione (GSH), increment of [Ca{sup 2+}], μ-calpain activation and externalization of PS in erythrocytes. Identifying molecular signals that induce eryptosis in lead intoxication is necessary to understand its physiopathology and chronic complications. - Graphical abstract: Fig. 1. (A) Blood lead concentration (PbB) and (B) phosphatidylserine externalization on erythrocyte membranes of non-lead exposed (□) and lead exposed workers (■). Values are mean ± SD. *Significantly different (P < 0.001). - Highlights: • Erythrocytes of lead exposed workers

Effects of diluents and plasma on honey bee (Apis mellifera L.) drone frozen-thawed semen fertility.

Science.gov (United States)

Gül, Aziz; Şahinler, Nuray; Onal, Ali G; Hopkins, Brandon K; Sheppard, Walter S

2017-10-01

Cryopreservation is an advanced method used to protect germplasm in liquid nitrogen. Honey bees are of special interest to protect because of their pollination activity and critical role in agriculture. There has been important progress in the cryopreservation of honey bee germplasm in recent years, leading to practical recovery of genetic material for breeding purposes following freezing. However, there remains room for improvement and the goal of the present study was to evaluate the effect of different "extenders" added post-thaw on the fertilization rate of cryopreserved honey bee semen. The purpose of adding extender post-thaw was to dilute the cryoprotectant to remove chemicals after centrifugation because of potential adverse effects. The control consisted of frozen-thawed semen without the addition of an extender; treatment groups included the addition of one of the following extenders: glucose solution, fresh ram semen plasma, fresh honey bee semen plasma, extender solution. All of the above treatments and frozen-thawed control were compared to fresh semen. For each group, 15 virgin queens were instrumentally inseminated with the semen-diluent solution and introduced into nucleus colonies to determine the brood patterns of the queens. Percentages of worker brood produced in the fresh semen, frozen-thawed semen control, glucose, fresh ram semen plasma, fresh honey bee semen plasma, and extender solution supplemented groups were 98.±1.1%, 47.0 ± 0.9%, 3.0 ± 0.8%, 0.3 ± 0.1%, 48.1 ± 4.1% and 40.3 ± 2.4%, respectively. Similiarly, spermatozoa numbers in the spermathecae of the same treatment groups were 3.6 × 10 6 , 1.6 × 10 6 , 7.3 × 10 5 , 4.7 × 10 5 , 8.1 × 10 5 , and 4.6 × 10 5 spermatozoa for the same treatment, respectively. The differences in both worker brood percentage and sperm count in the spermatheca were statistically significant (P drone semen plasma group. We found a positive correlation between sperm count in

Coal worker's pneumoconiosis

Science.gov (United States)

... this page: //medlineplus.gov/ency/article/000130.htm Coal worker's pneumoconiosis To use the sharing features on this page, please enable JavaScript. Coal worker's pneumoconiosis (CWP) is a lung disease that ...

Value Preferences of Social Workers.

Science.gov (United States)

Tartakovsky, Eugene; Walsh, Sophie D

2018-04-01

The current study examines value preferences of social workers in Israel. Using a theoretical framework of person-environment fit paradigm and theory of values, the study compared social workers (N = 641, mean age = 37.7 years, 91 percent female) with a representative sample of Israeli Jews (N = 1,600, mean age = 44.2, 52 percent female). Questionnaires included personal value preferences and sociodemographic variables (gender, age, education, religiosity, and immigrant status). Multivariate analysis of covariance showed that value preferences of social workers differed significantly from those of the general population. Analyses of covariance showed that social workers reported a higher preference for self-transcendence and a lower preference for conservation and self-enhancement values. Results have significance for the selection, training, and supervision of social workers. They suggest that it is important to assess to what extent selection processes for social workers are primarily recruiting social workers with shared values, thus creating an overly homogenous population of social workers. An understanding of personal value motivations can help social workers in their own process of self-development and growth, and to understand how the profession can fulfill their basic motivations.

Healthy worker survivor analysis in an occupational cohort study of Dutch agricultural workers

NARCIS (Netherlands)

Spierenburg, E. A. J.; Smit, L. A. M.; Heederik, D.; Robbe, P.; Hylkema, M. N.; Wouters, I. M.

High microbial exposures in farmers and agricultural workers are associated with less atopy. Although it has been speculated that healthy worker survival could be an explanation, this has not been studied so far. Therefore, we investigated the presence of healthy worker survival in a five-year

Increased Interleukin-4 production by CD8 and gammadelta T cells in health-care workers is associated with the subsequent development of active tuberculosis.

Science.gov (United States)

Ordway, Diane J; Costa, Leonor; Martins, Marta; Silveira, Henrique; Amaral, Leonard; Arroz, Maria J; Ventura, Fernando A; Dockrell, Hazel M

2004-08-15

We evaluated immune responses to Mycobacterium tuberculosis in 10 health-care workers (HCWs) and 10 non-HCWs and correlated their immune status with the development of active tuberculosis (TB). Twenty individuals were randomly recruited, tested, and monitored longitudinally for TB presentation. Peripheral blood mononuclear cells (PBMCs) from donors were stimulated with M. tuberculosis and tested for cell proliferation and the production of interferon (IFN)- gamma, interleukin (IL)-5, and IL-4, by use of enzyme-linked immunosorbent or flow-cytometric assays. HCWs had higher levels of cell proliferation (24,258 cpm) and IFN- gamma (6373 pg/mL) to M. tuberculosis than did non-HCWs (cell proliferation, 11,462 cpm; IFN- gamma, 3228 pg/mL). Six of 10 HCWs showed increased median percentages of CD8+IL-4+ (4.7%) and gammadelta +IL-4+ (2.3%) T cells and progressed to active TB. HCWs who remained healthy showed increased median percentages of CD8+IFN- gamma+ (25.0%) and gammadelta +IFN- gamma+ (8.0%) and lower percentages of CD8+IL-4+ (0.05%) and gammadelta +IL-4+ (0.03%) T cells.

Phenological, but not social, variation associated with climate differences in a eusocial sweat bee, Halictus ligatus, nesting in southern Ontario

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Miriam H. Richards

2015-03-01

Full Text Available Studies of annual and geographic variation in eusocial bee populations suggest that more stringent environmental conditions result in stronger reproductive skew favouring queens, while moderate conditions favour increasing worker reproduction. To test these predictions, we compared the phenology and colony development of H. ligatus nesting in St. Catharines, Ontario, Canada to a previously studied aggregation 90 km north of St. Catharines, in Victoria, Ontario. Despite the close proximity of these two locations, St. Catharines has markedly shorter winters and longer summers. Comparisons between St. Catharines in 2006 and Victoria in the 1980s and 1990s incorporate both geographic differences in climate and temporal differences due to climate change. We predicted that St. Catharines foundress queens should emerge from hibernation and initiate nests earlier in spring, giving them time to produce more workers. Since earlier studies indicated that queens have difficulty suppressing worker reproduction in larger colonies, we also predicted higher rates of worker ovarian development in St. Catharines. In spring and summer 2006, we excavated 65 H. ligatus nests, comparing their contents to 713 specimens collected in pan traps. As predicted, nests were initiated about a month earlier in St. Catharines than in Victoria, but contrary to prediction, fewer workers were produced in St. Catharines. St. Catharines workers were just as likely to have developed ovaries as Victoria workers. About 40% of St. Catharines workers were classified as reproductive, and larger reproductive workers tended to have higher ovarian scores. Early queen mortality in the longer nest cycle of St. Catharines bees may have enhanced opportunities for worker reproduction despite their smaller numbers. Novel features of H. ligatus sociobiology in St. Catharines included evidence that queens can initiate new nests following the loss of their first brood, overlap between worker and gyne

Eryptosis in lead-exposed workers.

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Aguilar-Dorado, Itzel-Citlalli; Hernández, Gerardo; Quintanar-Escorza, Martha-Angelica; Maldonado-Vega, María; Rosas-Flores, Margarita; Calderón-Salinas, José-Víctor

2014-12-01

Eryptosis is a physiological phenomenon in which old and damaged erythrocytes are removed from circulation. Erythrocytes incubated with lead have exhibited major eryptosis. In the present work we found evidence of high levels of eryptosis in lead exposed workers possibly via oxidation. Blood samples were taken from 40 male workers exposed to lead (mean blood lead concentration 64.8μg/dl) and non-exposed workers (4.2μg/dl). The exposure to lead produced an intoxication characterized by 88.3% less δ-aminolevulinic acid dehydratase (δALAD) activity in lead exposed workers with respect to non-lead exposed workers. An increment of oxidation in lead exposed workers was characterized by 2.4 times higher thiobarbituric acid-reactive substance (TBARS) concentration and 32.8% lower reduced/oxidized glutathione (GSH/GSSG) ratio. Oxidative stress in erythrocytes of lead exposed workers is expressed in 192% higher free calcium concentration [Ca(2+)]i and 1.6 times higher μ-calpain activity with respect to non-lead exposed workers. The adenosine triphosphate (ATP) concentration was not significantly different between the two worker groups. No externalization of phosphatidylserine (PS) was found in non-lead exposed workers (lead exposed workers showed 2.82% externalization. Lead intoxication induces eryptosis possibly through a molecular pathway that includes oxidation, depletion of reduced glutathione (GSH), increment of [Ca(2+)], μ-calpain activation and externalization of PS in erythrocytes. Identifying molecular signals that induce eryptosis in lead intoxication is necessary to understand its physiopathology and chronic complications. Copyright © 2014 Elsevier Inc. All rights reserved.

Office home care workers' occupational health: associations with workplace flexibility and worker insecurity.

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Zeytinoglu, Isik U; Denton, Margaret; Davies, Sharon; Plenderleith, Jennifer Millen

2009-05-01

Office home care workers provide support to visiting staff, although their work tends to be invisible in many respects. This paper focuses on managers, supervisors, coor dinators, case managers and office administrative staff in home care. We examine the effects of workplace flexibility and worker insecurity on office home care workers' occupational health, particularly their self-reported stress and musculoskeletal disorders. Data come from our survey of 300 home care office staff in a mid-sized city in Ontario. Results show that workers' perceptions of insecurity are positively associated with musculoskeletal disorders but not workplace flexibility measures. We recommend that managers and other decision-makers in the home care field pay attention to the perceptions of workers' insecurity in initiating workplace flexibility measures.

Performance factors of mobile rich media job aids for community health workers.

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Florez-Arango, Jose F; Iyengar, M Sriram; Dunn, Kim; Zhang, Jiajie

2011-01-01

To study and analyze the possible benefits on performance of community health workers using point-of-care clinical guidelines implemented as interactive rich media job aids on small-format mobile platforms. A crossover study with one intervention (rich media job aids) and one control (traditional job aids), two periods, with 50 community health workers, each subject solving a total 15 standardized cases per period per period (30 cases in total per subject). Error rate per case and task, protocol compliance. A total of 1394 cases were evaluated. Intervention reduces errors by an average of 33.15% (p = 0.001) and increases protocol compliance 30.18% (p technologies in general, and the use of rich media clinical guidelines on cell phones in particular, for the improvement of community health worker performance in developing countries.

A primer for workers' compensation.

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Bible, Jesse E; Spengler, Dan M; Mir, Hassan R

2014-07-01

A physician's role within a workers' compensation injury extends far beyond just evaluation and treatment with several socioeconomic and psychological factors at play compared with similar injuries occurring outside of the workplace. Although workers' compensation statutes vary among states, all have several basic features with the overall goal of returning the injured worker to maximal function in the shortest time period, with the least residual disability and shortest time away from work. To help physicians unfamiliar with the workers' compensation process accomplish these goals. Review. Educational review. The streamlined review addresses the topics of why is workers' compensation necessary; what does workers' compensation cover; progression after work injury; impairment and maximum medical improvement, including how to use the sixth edition of American Medical Association's (AMA) Guides to the evaluation of permanent impairment (Guides); completion of work injury claim after impairment rating; independent medical evaluation; and causation. In the "no-fault" workers' compensation system, physicians play a key role in progressing the claim along and, more importantly, getting the injured worker back to work as soon as safely possible. Physicians should remain familiar with the workers' compensation process, along with how to properly use the AMA Guides. Copyright © 2014 Elsevier Inc. All rights reserved.

Healing or harming? Healthcare provider interactions with injured workers and insurers in workers' compensation systems.

Science.gov (United States)

Kilgour, Elizabeth; Kosny, Agnieszka; McKenzie, Donna; Collie, Alex

2015-03-01

Healthcare providers (HCPs) are influential in the injured worker's recovery process and fulfil many roles in the delivery of health services. Interactions between HCPs and insurers can also affect injured workers' engagement in rehabilitation and subsequently their recovery and return to work. Consideration of the injured workers' perceptions and experiences as consumers of medical and compensation services can provide vital information about the quality, efficacy and impact of such systems. The aim of this systematic review was to identify and synthesize published qualitative research that focused on the interactions between injured workers, HCPs and insurers in workers' compensation systems in order to identify processes or interactions which impact injured worker recovery. A search of six electronic databases for literature published between 1985 and 2012 revealed 1,006 articles. Screening for relevance identified 27 studies which were assessed for quality against set criteria. A final 13 articles of medium and high quality were retained for data extraction. Findings were synthesized using a meta-ethnographic approach. Injured workers reported that HCPs could play both healing and harming roles in their recovery. Supportive patient-centred interaction with HCPs is important for injured workers. Difficult interactions between HCPs and insurers were highlighted in themes of adversarial relations and organisational pressures. Insurer and compensation system processes exerted an influence on the therapeutic relationship. Recommendations to improve relationships included streamlining administrative demands and increasing education and communication between the parties. Injured workers with long term complex injuries experience difficulties with healthcare in the workers' compensation context. Changes in insurer administrative demands and compensation processes could increase HCP participation and job satisfaction. This in turn may improve injured worker recovery

[Indian workers in Oman].

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Longuenesse, E

1985-01-01

Until recently Oman was a country of emigration, but by 1980 an estimated 200,000 foreign workers were in the country due to the petroleum boom. Almost 1/3 of the estimated 300,000 Indian workers in the Gulf states were in Oman, a country whose colonial heritage was closely tied to that of India and many of whose inhabitants still speak Urdu. The number of work permits granted to Indians working in the private sector in Oman increased from 47,928 in 1976 to 80,787 in 1980. An estimated 110,000 Indians were working in Oman in 1982, the great majority in the construction and public works sector. A few hundred Indian women were employed by the government of Oman, as domestics, or in other capacities. No accurate data is available on the qualifications of Indian workers in Oman, but a 1979 survey suggested a relatively low illiteracy rate among them. 60-75% of Indians in Oman are from the state of Kerala, followed by workers from the Punjab and the southern states of Tamil Nadu and Andhra Pradesh and Bombay. Indian workers are recruited by specialized agencies or by friends or relatives already employed in Oman. Employers in Oman prefer to recruit through agencies because the preselection process minimizes hiring of workers unqualified for their posts. Officially, expenses of transportation, visas, and other needs are shared by the worker and the employer, but the demand for jobs is so strong that the workers are obliged to pay commissions which amount to considerable sums for stable and well paying jobs. Wages in Oman are however 2 to 5 times the level in India. Numerous abuses have been reported in recruitment practices and in failure of employers in Oman to pay the promised wages, but Indian workers have little recourse. At the same level of qualifications, Indians are paid less then non-Omani Arabs, who in turn receive less than Oman nationals. Indians who remain in Oman long enough nevertheless are able to support families at home and to accumulate considerable

Change in airway inflammatory markers in Danish energy plant workers during a working week

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Yuduo Zheng

2014-09-01

Full Text Available [b]Introduction.[/b] It is well known that exposure to organic dust can cause adverse respiratory effect. The pathogen-associated molecular patterns (PAMPS in the organic dust, such as endotoxin from Gram-negative bacteria cell wall and fungal components, can trigger the release of cytokine (e.g. Interleukin 1β (IL-1β and chemokine (e.g. Interleukin 8 (IL-8 from the immune cells in the airways. [b]Objective.[/b] To evaluate the potential inflammatory effects of organic dust exposure in energy plants in Denmark. [b]Materials and methods[/b]. Nasal lavage (NAL and exhaled breath condensate (EBC were sampled at Monday morning (referred to as before work and again at Thursday afternoon (referred to as after work. NAL IL-8, EBC pH, IL-1β concentration were measured. Personal exposure to endotoxin and dust was calculated from time spent on different tasks and measured average work area exposures. [b]Results.[/b] Before work, workers from biofuel plants had a higher IL-1β and IL-8 concentration compared to conventional fuel plants (control group. Specifically, the IL-1β level of moderately and most exposed group, and IL-8 level of the least exposed group were higher compared to the control group. The changes of IL-1β, pH and IL-8 during a work week were not significant. Workers with rhinitis had a lower percentage change of IL-8 compared to healthy workers. [b]Conclusions[/b]. An increased level of EBC IL-1β in biofuel energy plant workers before work indicated a chronic or sub-chronic inflammation. The percentage change of IL-8 was lower in workers with rhinitis compared to healthy workers.

Pulmonary function in automobile repair workers

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Chattopadhyay O

2007-01-01

Full Text Available Background : Automobile repair shop is a place where workers are exposed to harmful chemicals and toxic substances. Objective : To study the occurrence of obstructive and restrictive pulmonary impairment among automobile garage workers. Methods : A cross sectional study involving 151 automobile garage workers from 14 randomly selected garages of urban Kolkata. The study variables were Forced Expiratory Volume in 1 second (FEV 1 , Forced Vital Capacity (FVC, Peak Expiratory Flow Rate (PE FR, age, smoking habit, duration of work, type of work, and respiratory symptoms. The study was analysed using Regression equations, and Chi-square test. Results : All the workers were male. Obstructive impairment was seen in 25.83% of the workers whereas restrictive impairment was seen in 21.19% of the workers. Mixed obstructive and restrictive impairment was seen in 10.6% of the workers. The frequency of obstructive impairment was higher in older workers. In the age group of less than 20 years, 13.6% of the workers had obstructive impairment while 42.86% of workers above 40 years of age had obstructive impairment. Obstructive impairment was more frequently observed in battery repair workers (58.33% and spray painters (37.5% while 16.67% of the body repair workers and 30.19% of the engine mechanics had obstructive impairment. Obstructive impairment was more frequently observed in smokers (53.1 % as compared to ex-smokers (33.3% and non-smokers (6.4%. Obstructive impairment was more frequently observed in workers who had been working for a longer duration. Conclusion: Nearly 36.4% of the automobile garage workers had some form of pulmonary function impairment; obstructive and/or restrictive. The use of personal protective equipment, worker education, and discontinuation of the use of paints containing toxic pigments are recommended.

Ultrastructure of the intramandibular gland of workers and queens of the stingless bee, Melipona quadrifasciata.

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Da Cruz-Landim, Carminda; Gracioli-Vitti, Luciana F; Abdalla, Fábio C

2011-01-01

The intramandibular glands of workers and queens of Melipona quadrifasciata Lepeletier (Hymenoptera: Apidae), at different ages and from different functional groups, were studied using light and transmission electron microscopy. The results demonstrated that these glands are composed of two types of secretory structures: 1.A hypertrophied epidermis on the dorsal side of the mandible that is an epithelial gland. 2. Free secretory cells filling the inner spaces of the appendices that constitute a unicellular gland. The epithelial gland is larger in the young (1-2-day-old workers), and the gland becomes involuted during the nurse worker stage. The unicellular glands of the workers posses some secretion during all of the studied phases, but secretory activity is more intensive in the foraging workers. Vesicles of secretion are absent in the unicellular glands of queens. These results demonstrate that these glands show functional adaptations in different castes corresponding to the functions of each caste.

Micronuclei rate in workers of Novi Han radioactive waste repository

International Nuclear Information System (INIS)

Atamasova, P.; Hadjidekova, V.

2003-01-01

A cytogenetic study has been carried out by the micronucleus test of lymphocytes from the peripheral blood of 30 workers from the Novi Han radioactive waste repository. The results are compared to the results of a control group of 6 persons from the administrative staff, and to outside group of 39 healthy persons. All persons are questioned through a special questionnaire about their occupational, medical, and social status. The rate of the cells with micronuclei and the total number of the micronuclei are analysed in the peripheral blood lymphocytes using the cytogenesis-block micronucleus test. The comparison of the results does not show an increase of the lymphocytes with micronuclei in the workers

Medical Surveillance for Former Workers

Energy Technology Data Exchange (ETDEWEB)

Tim Takaro

2009-05-29

The Former Hanford Worker Medical Monitoring Program, directed by the Occupational and Environmental Medicine Program at the University of Washington, served former production and other non-construction workers who were potentially exposed to workplace hazards while working for the USDOE or its contractors at Hanford. The USDOE Former Workers Program arose from Congressional action in the Defense Authorization of 1993 (Public Law 102). Section 3162 stated that, “The Secretary shall establish and carry out a program for the identification and ongoing medical evaluation of current and former Department of Energy employees who are subject to significant health risks as a result of exposure of such employees to hazardous or radioactive substances during such employment.” (This also covers former employees of USDOE contractors and subcontractors.) The key objective has been to provide these former workers with medical evaluations in order to determine whether workers have experienced significant risk due to workplace exposure to hazards. Exposures to asbestos, beryllium, and noise can produce specific medical conditions: asbestosis, berylliosis, and noise-induced hearing loss (NIHL). Each of these conditions can be identified by specific, non-invasive screening tests, which are widely available. Treatments are also available for individuals affected by these conditions. This project involved two phases. Phase I involved a needs and risk assessment, characterizing the nature and extent of workplace health hazards which may have increased the risk for long-term health effects. We categorized jobs and tasks by likelihood of exposures to specific workplace health hazards; and located and established contact with former Hanford workers. Phase II involved implementation of medical monitoring programs for former workers whose individual work history indicated significant risk for adverse health effects. We identified 118,000 former workers, employed from 1943 to 1997

Decreased numbers of CD4+ naive and effector memory T cells, and CD8+ naïve T cells, are associated with trichloroethylene exposure

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H Dean eHosgood

2012-01-01

Full Text Available Trichloroethylene (TCE is a volatile chlorinated organic compound that is commonly used as a solvent for lipophilic compounds. Although recognized as an animal carcinogen, TCE’s carcinogenic potential in humans is still uncertain. We have carried out a cross-sectional study of 80 workers exposed to TCE and 96 unexposed controls matched on age and sex in Guangdong, China to study TCE’s early biologic effects. We previously reported that the total lymphocyte count and each of the major lymphocyte subsets (i.e., CD4+ T cells, CD8+ T cells, natural killer (NK cells, and B cells were decreased in TCE-exposed workers compared to controls, suggesting a selective effect on lymphoid progenitors and/or lymphocyte survival. To explore which T lymphocyte subsets are affected, we investigated the effect of TCE exposure on the numbers of CD4+ naïve and memory T cells, CD8+ naïve and memory T cells, and regulatory T cells by FACS analysis. Linear regression of each subset was used to test for differences between exposed workers and controls adjusting for potential confounders. We observed that CD4+ and CD8+ naïve T cell counts were about 8% (p = 0.056 and 17% (p = 0.0002 lower, respectively, among exposed workers. CD4+ effector memory T cell counts were decreased by about 20% among TCE exposed workers compared to controls (p = 0.001. The selective targeting of TCE on CD8+ naïve and possibly CD4+ naive T cells, and CD4+ effector memory T cells, provide further insights into the immunosuppression-related response of human immune cells upon TCE exposure.

Determination of uranium in the red blood cells of the workers in the chemical processing of uranium ore

International Nuclear Information System (INIS)

Nosek, J.; Simkova, M.; Kukula, F.; Musil, K.

1975-04-01

Neutron activation analysis was used in determining uranium in the venous blood erythrocytes of controls and of workers exposed to occupational hazards in a uranium chemical treatment plant. While 4.1 +- 2.6 ppb of uranium was found in dry matter of the erythrocytes in controls, 6.5 +- 2.1 ppb of uranium was ascertained in dry matter of the erythrocytes in occupationally exposed workers of a wet preparation plant, and 37.2 +- 20.2 ppb of uranium in the erythrocytes in workers of a dry cleaning plant. (author)

The Prevalence of Carpal Tunnel Syndrome in Latino Poultry Processing Workers and Other Latino Manual Workers

Science.gov (United States)

Cartwright, Michael S.; Walker, Francis O.; Blocker, Jill N.; Schulz, Mark R.; Arcury, Thomas A.; Grzywacz, Joseph G.; Mora, Dana; Chen, Haiying; Marín, Antonio J.; Quandt, Sara A.

2011-01-01

Objective To determine the prevalence of carpal tunnel syndrome (CTS) in Latino poultry processing workers. Methods Symptoms and nerve conduction studies were used to prospectively assess 287 Latino poultry processing workers and 226 Latinos in other manual labor occupations. Results The prevalence of CTS was higher in poultry processing (8.7%) compared to non-poultry manual workers (4.0%, p poultry workers was 2.51 (95% CI of 1.80 to 3.50) compared to non-poultry workers. Within the poultry workers, those who performed packing, sanitation, and chilling had a trend toward less CTS than those who performed tasks requiring more repetitive and strenuous hand movements. Discussion Latino poultry processing workers have a high prevalence of CTS, which likely results from the repetitive and strenuous nature of the work. PMID:22258161

An influence of occupational exposure on level of chromosome aberrations in nuclear power plant workers

International Nuclear Information System (INIS)

Birute Griciene; Grazina Slapsyte

2007-01-01

Complete text of publication follows. Objective. The workers of Ignalina Nuclear Power Plant (INPP) receive the highest occupational ionising radiation doses in Lithuania. Their occupational exposure results mainly from external low LET gamma radiation. Some workers receive additional internal and neutron exposure. Though exposure doses are generally low and don't exceed the annual dose limit, the higher doses are obtained during outages. The aim of the present study was to analyse chromosome aberration frequencies in lymphocytes of INPP workers exposed to the different types of ionising radiation. Methods. The blood sampling of 52 INPP male workers was performed in 2004-2006. For 29 workers radiation exposure resulted from the external gamma rays only. Their mean annual dose averaged over the 3-year period prior blood sampling was 11.7±8.7 mSv. The mean cumulative dose - 197.7±174.7 mSv. 15 workers had an intake of gamma radionuclides ( 60 Co, 137 Cs), contributing to the doses less than 0.1 mSv. Their mean cumulative dose - 278.2±191.9 mSv. The mean annual dose averaged over the 3-year period prior blood sampling was 11.8±5.3 mSv. For 8 subjects neutron doses below 0.2 mSv were recorded. Their mean annual dose averaged over the 3-year period prior blood sampling was 7.0±2.9 mSv. The mean cumulative dose was 241.8±93.0 mSv. Heparinized venous blood samples were taken and cultures were initiated according to the standard procedures. Phytohaemagglutinin (7.8 μg/ml) stimulated cultures were incubated at 37degC for 72 hours in RPMI 1640 medium supplemented with 12% heat-inactivated newborn calf serum, 40 μg/ml gentamycin. Colchicine was added to the culture during the initiation at a final concentration of 0,25 μg/ml. The harvested lymphocytes were treated with hypotonic KCl (0,075 M) and then fixed in methanol-glacial acetic acid (3:1). Flame-dried slides were stained with Giemsa, coded and scored blind. Generally 500 first-division cells per individual were

Lead toxicity on hematological parameters in workers with occupational exposure to lead

International Nuclear Information System (INIS)

Dursun, N.; Koese, K.

1998-01-01

The effects of lead on hematological parameters were studied in lead exposed male workers occupied for 17.84+-4.22 years in a metal powder producing factory in Kayseri, Turkey and control male workers in same city. Blood lead and plasma zinc levels were measured by Atomic Absorption Spectrophotometry (AAS) and hematological parameters by Culture Counter S. The lead exposure workers had higher lead levels (13.81+- 9.21 mug/dl) as compared to control subjects (2.37+-0.10 mug/dl). No difference was observed in the plasma zinc levels of both groups. As indices of lead exposure, red blood cell (RBC) counts, hemoglobin (Hb), and hematocrit (Hct) values significantly decreased. Mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular haemoglobin concentration (MCHC) significantly increased except MCV. There was also an increase in MCV, but it was not significant. (author)

Chromosomal abnormalities in soft coal open-cast mining workers

Energy Technology Data Exchange (ETDEWEB)

Sram, R.J.; Hola, N.; Kotesovec, F.; Vavra, R.

1985-12-01

Chromosome aberration tests on cultured peripheral blood lymphocytes were carried out in two groups of open-cast mining workers engaged in stripping operations (Group I) and digging operations (Group II), in a group of coal cleaning plant workers used as a positive control, and in a group of nonexposed subjects serving as matching controls. Peripheral blood samples in group I and group II miners were collected in March and June of 1984, the antimutagenic potential of long-term prophylactic vitamin administrations (1 g of ascorbic acid given daily for a period of 3 months and 100 mg of vitamin A a day for two 5-day cycles) initiated after the first blood sampling was tested in group II miners. The frequency of aberrant cells (% AB.C.) found in the cultured lymphocytes of group I miners was increased at both times of measurement (2.41% AB.C. and 2.29% AB.C.), in group II miners given the vitamin prophylaxis it dropped significantly (P greater than 0.01) from the initial 3.16% AB.C. in March to 1.77% AB.C. in June, and in the group of coal cleaning plant workers (1.30% AB.C.) it was more or less equal to that of matching controls (1.21% AB.C.). Implicitly, coal dust alone can hardly be made responsible for the rise in % AB.C. It appears that the increase in frequency of chromosome aberrations observed in soft coal open-cast mining workers rather reflects an increased risk of genetic injury due to exposure to ever-present fumes and fire hazards that may give rise to the mutagenic chemicals belonging to a class of polycyclic aromatic hydrocarbons. The antimutagenic effect of ascorbic acid prophylaxis was characterized by a significant drop in % AB.C. and a speed-up of the lymphocyte cell cycle expressed as the proliferating rate index (PRI) whose value rose from the original 1.41 to 1.69, thus reaching the PRI value of matching controls (1.63).

Hemocyte-mediated phagocytosis differs between honey bee (Apis mellifera) worker castes.

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Hystad, Eva Marit; Salmela, Heli; Amdam, Gro Vang; Münch, Daniel

2017-01-01

Honey bees as other insects rely on the innate immune system for protection against diseases. The innate immune system includes the circulating hemocytes (immune cells) that clear pathogens from hemolymph (blood) by phagocytosis, nodulation or encapsulation. Honey bee hemocyte numbers have been linked to hemolymph levels of vitellogenin. Vitellogenin is a multifunctional protein with immune-supportive functions identified in a range of species, including the honey bee. Hemocyte numbers can increase via mitosis, and this recruitment process can be important for immune system function and maintenance. Here, we tested if hemocyte mediated phagocytosis differs among the physiologically different honey bee worker castes (nurses, foragers and winter bees), and study possible interactions with vitellogenin and hemocyte recruitment. To this end, we adapted phagocytosis assays, which-together with confocal microscopy and flow cytometry-allow qualitative and quantitative assessment of hemocyte performance. We found that nurses are more efficient in phagocytic uptake than both foragers and winter bees. We detected vitellogenin within the hemocytes, and found that winter bees have the highest numbers of vitellogenin-positive hemocytes. Connections between phagocytosis, hemocyte-vitellogenin and mitosis were worker caste dependent. Our results demonstrate that the phagocytic performance of immune cells differs significantly between honey bee worker castes, and support increased immune competence in nurses as compared to forager bees. Our data, moreover, provides support for roles of vitellogenin in hemocyte activity.

Hemocyte-mediated phagocytosis differs between honey bee (Apis mellifera worker castes.

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Eva Marit Hystad

Full Text Available Honey bees as other insects rely on the innate immune system for protection against diseases. The innate immune system includes the circulating hemocytes (immune cells that clear pathogens from hemolymph (blood by phagocytosis, nodulation or encapsulation. Honey bee hemocyte numbers have been linked to hemolymph levels of vitellogenin. Vitellogenin is a multifunctional protein with immune-supportive functions identified in a range of species, including the honey bee. Hemocyte numbers can increase via mitosis, and this recruitment process can be important for immune system function and maintenance. Here, we tested if hemocyte mediated phagocytosis differs among the physiologically different honey bee worker castes (nurses, foragers and winter bees, and study possible interactions with vitellogenin and hemocyte recruitment. To this end, we adapted phagocytosis assays, which-together with confocal microscopy and flow cytometry-allow qualitative and quantitative assessment of hemocyte performance. We found that nurses are more efficient in phagocytic uptake than both foragers and winter bees. We detected vitellogenin within the hemocytes, and found that winter bees have the highest numbers of vitellogenin-positive hemocytes. Connections between phagocytosis, hemocyte-vitellogenin and mitosis were worker caste dependent. Our results demonstrate that the phagocytic performance of immune cells differs significantly between honey bee worker castes, and support increased immune competence in nurses as compared to forager bees. Our data, moreover, provides support for roles of vitellogenin in hemocyte activity.

76 FR 61749 - SpectraWatt, Inc. Including On-Site Leased Workers From Kelly Services Hopewell Junction, NY...

Science.gov (United States)

2011-10-05

... to the production of solar cells for their application in solar panels. The worker group includes on..., during the period of investigation, imports of articles like or directly competitive with solar cells produced by the subject firm have increased, and that the increased imports of solar cells (or like or...

Resilience of honeybee colonies via common stomach: A model of self-regulation of foraging.

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Thomas Schmickl

Full Text Available We propose a new regulation mechanism based on the idea of the "common stomach" to explain several aspects of the resilience and homeostatic regulation of honeybee colonies. This mechanism exploits shared pools of substances (pollen, nectar, workers, brood that modulate recruitment, abandonment and allocation patterns at the colony-level and enable bees to perform several survival strategies to cope with difficult circumstances: Lack of proteins leads to reduced feeding of young brood, to early capping of old brood and to regaining of already spent proteins through brood cannibalism. We modeled this system by linear interaction terms and mass-action law. To test the predictive power of the model of this regulatory mechanism we compared our model predictions to experimental data of several studies. These comparisons show that the proposed regulation mechanism can explain a variety of colony level behaviors. Detailed analysis of the model revealed that these mechanisms could explain the resilience, stability and self-regulation observed in honeybee colonies. We found that manipulation of material flow and applying sudden perturbations to colony stocks are quickly compensated by a resulting counter-acting shift in task selection. Selective analysis of feedback loops allowed us to discriminate the importance of different feedback loops in self-regulation of honeybee colonies. We stress that a network of simple proximate mechanisms can explain significant colony-level abilities that can also be seen as ultimate reasoning of the evolutionary trajectory of honeybees.

Prevalence of abnormal radiological findings in health care workers with latent tuberculosis infection and correlations with T cell immune response.

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Rajnish Joshi

2007-08-01

Full Text Available More than half of all health care workers (HCWs in high TB-incidence, low and middle income countries are latently infected with tuberculosis (TB. We determined radiological lesions in a cohort of HCWs with latent TB infection (LTBI in India, and determined their association with demographic, occupational and T-cell immune response variables.We obtained chest radiographs of HCWs who had undergone tuberculin skin test (TST and QuantiFERON-TB Gold In Tube (QFT, an interferon-gamma release assay, in a previous cross-sectional study, and were diagnosed to have LTBI because they were positive by either TST or QFT, but had no evidence of clinical disease. Two observers independently interpreted these radiographs using a standardized data form and any discordance between them resolved by a third observer. The radiological diagnostic categories (normal, suggestive of inactive TB, and suggestive of active TB were compared with results of TST, QFT assay, demographic, and occupational covariates.A total of 330 HCWs with positive TST or QFT underwent standard chest radiography. Of these 330, 113 radiographs (34.2% were finally classified as normal, 206 (62.4% had lesions suggestive of inactive TB, and 11 (3.4% had features suggestive of active TB. The mean TST indurations and interferon-gamma levels in the HCWs in these three categories were not significantly different. None of the demographic or occupational covariates was associated with prevalence of inactive TB lesions on chest radiography.In a high TB incidence setting, nearly two-thirds of HCWs with latent TB infection had abnormal radiographic findings, and these findings had no clear correlation with T cell immune responses. Further studies are needed to verify these findings and to identify the causes and prognosis of radiologic abnormalities in health care workers.

Study of insomnia in rotating shift-workers

Directory of Open Access Journals (Sweden)

Kaushik Chatterjee

2017-01-01

Full Text Available Background: Shift-workers commonly suffer from insomnia. This study evaluates different domains of insomnia. Aim: This study was aimed to study sleep and insomnia in rotating shift-workers and compare with day-workers. Materials and Methods: This was case–control study. The sleep of rotating shift-workers is compared with day workers using Athens Insomnia Scale. Results: Rotating shift-workers had significantly higher scores on Athens insomnia scale on domains of initial, intermediate and terminal insomnia than day workers. Duration and quality of sleep and sense of well-being are lower in rotating shift-workers. Rotating shift-workers also experienced more day-time sleepiness than day workers. However, there was no difference in perceived physical and mental functioning between the two groups. Conclusion: Individuals working in rotating shifts for more than 15 days have significantly higher prevalence of insomnia than day-workers.

Assessment of DNA Damage in Peripheral Blood Lymphocytes of Radiation Workers at Al-Tuwaitha Site by Using the Sister Chromatid Exchange and the Comet Assay

International Nuclear Information System (INIS)

Ali, A.K.; Muttar, A.J.; Khayon, S.K.; Haider, Y.L.; Ali, H.F.; Abdullah, A.K.

2015-01-01

The sister chromatid exchange was performed on peripheral blood lymphocytes obtained from 40 individuals of workers occupationally exposed to low ionizing radiation doses in Al-Tuwaitha site due to decommissioning to radioactive contamination then compared with 40 control individuals living in Baghdad. SCEs were scored in metaphase chromosomes were identified by fluorescent plus Giemsa staining (Figure 2).The mean frequencies of SCEs per cell differed significantly (p≺0 0.05) between individuals of radiation workers and control, being 7.78 0.45 SCE/cells and 6.28 0.22 SCE/cells , respectively. However SCE frequency was statistically significant (P≺0 0.05) among radiation workers as compared to control individuals.

Risks for radiation workers

International Nuclear Information System (INIS)

Rotblat, J.

1978-01-01

The following topics are discussed: recommendations of the International Commission on Radiological Protection; methods for determining dose limits to workers; use of data from survivors of Hiroshima and Nagasaki for estimating risk factors; use of data from survivors of nuclear explosions in Marshall Islands, uranium miners, and patients exposed to diagnostic and therapeutic radiation; risk factors for radioinduced malignancies; evidence that risk factors for persons exposed to partial-body radiation and Japanese survivors are too low; greater resistance of A-bomb survivors to radiation; and radiation doses received by U.K. medical workers and by U.K. fuel reprocessing workers. It is suggested that the dose limit for radiation workers should be reduced by a factor of 5

Advanced worker protection system

Energy Technology Data Exchange (ETDEWEB)

Caldwell, B.; Duncan, P.; Myers, J. [Oceaneering Space Systems, Houston, TX (United States)

1995-10-01

The Department of Energy (DOE) is in the process of defining the magnitude and diversity of Decontamination and Decommissioning (D&D) obligations at its numerous sites. The DOE believes that existing technologies are inadequate to solve many challenging problems such as how to decontaminate structures and equipment cost effectively, what to do with materials and wastes generated, and how to adequately protect workers and the environment. Preliminary estimates show a tremendous need for effective use of resources over a relatively long period (over 30 years). Several technologies are being investigated which can potentially reduce D&D costs while providing appropriate protection to DOE workers. The DOE recognizes that traditional methods used by the EPA in hazardous waste site clean up activities are insufficient to provide the needed protection and worker productivity demanded by DOE D&D programs. As a consequence, new clothing and equipment which can adequately protect workers while providing increases in worker productivity are being sought for implementation at DOE sites. This project describes the development of an Advanced Worker Protection System (AWPS) which will include a life-support backpack with liquid air for cooling and as a supply of breathing gas, protective clothing, respirators, communications, and support equipment.

Radiation haunts shipyard workers

International Nuclear Information System (INIS)

Torrey, L.

1978-01-01

The apparent link recently found by Dr. Najarian between cancer among workers at a US Naval dockyard where up to 5000 civilian employees have been exposed to low dose irradiation while servicing nuclear ships and their radiation exposure is discussed. The study has revealed that 38.4% of the deaths of nuclear workers at the Portsmouth Naval Shipyard in New Hampshire were caused by cancer while the comparable rate for non-nuclear shipyard workers was 21.7% and the national average in the United States is 18%. The Portsmouth study, launched in October 1977, was based on a survey of 1722 death certificates of shipyard employees and interviews with 592 next-of-kin. In addition the results show that the rate of leukaemia of the shipyard workers was 450% higher than that of the general population, and the incidence of lymph gland cancers was 125% higher than the national rate. The most startling statistics compared mortality among workers aged 60 to 69. In this age group nearly 60% of the nuclear employees had died of cancer, while the cancer death rate among non-nuclear workers was only 26%. If these results are confirmed present ideas concerning the effects of low doses of radiation must be challenged. (U.K.)

Advanced worker protection system

International Nuclear Information System (INIS)

Caldwell, B.; Duncan, P.; Myers, J.

1995-01-01

The Department of Energy (DOE) is in the process of defining the magnitude and diversity of Decontamination and Decommissioning (D ampersand D) obligations at its numerous sites. The DOE believes that existing technologies are inadequate to solve many challenging problems such as how to decontaminate structures and equipment cost effectively, what to do with materials and wastes generated, and how to adequately protect workers and the environment. Preliminary estimates show a tremendous need for effective use of resources over a relatively long period (over 30 years). Several technologies are being investigated which can potentially reduce D ampersand D costs while providing appropriate protection to DOE workers. The DOE recognizes that traditional methods used by the EPA in hazardous waste site clean up activities are insufficient to provide the needed protection and worker productivity demanded by DOE D ampersand D programs. As a consequence, new clothing and equipment which can adequately protect workers while providing increases in worker productivity are being sought for implementation at DOE sites. This project describes the development of an Advanced Worker Protection System (AWPS) which will include a life-support backpack with liquid air for cooling and as a supply of breathing gas, protective clothing, respirators, communications, and support equipment

Workplace violence against homecare workers and its relationship with workers health outcomes: a cross-sectional study.

Science.gov (United States)

Hanson, Ginger C; Perrin, Nancy A; Moss, Helen; Laharnar, Naima; Glass, Nancy

2015-01-17

Consumer-driven homecare models support aging and disabled individuals to live independently through the services of homecare workers. Although these models have benefits, including autonomy and control over services, little evidence exists about challenges homecare workers may face when providing services, including workplace violence and the negative outcomes associated with workplace violence. This study investigates the prevalence of workplace violence among homecare workers and examines the relationship between these experiences and homecare worker stress, burnout, depression, and sleep. We recruited female homecare workers in Oregon, the first US state to implement a consumer driven homecare model, to complete an on-line or telephone survey with peer interviewers. The survey asked about demographics and included measures to assess workplace violence, fear, stress, burnout, depression and sleep problems. Homecare workers (n = 1,214) reported past-year incidents of verbal aggression (50.3% of respondents), workplace aggression (26.9%), workplace violence (23.6%), sexual harassment (25.7%), and sexual aggression (12.8%). Exposure was associated with greater stress (p workplace aggression buffered homecare workers against negative work and health outcomes. To ensure homecare worker safety and positive health outcomes in the provision of services, it is critical to develop and implement preventive safety training programs with policies and procedures that support homecare workers who experience harassment and violence.

Sex allocation and sex-dependent selection for body size in Trypoxylon rogenhoferi Kohl (Hymenoptera, Sphecidae Alocação sexual e seleção sexo-dependente para tamanho de corpo em Trypoxylon rogenhoferi Kohl (Hymenoptera, Sphecidae

Directory of Open Access Journals (Sweden)

Rui Carlos Peruquetti

2003-12-01

Full Text Available Two populations of the wasp Trypoxylon rogenhoferi Kohl, 1884 from São Carlos and Luís Antônio, State of São Paulo, Brazil, were observed and sampled from May 1999 to February 2001 using trap-nests. This mass-provisioning wasp was used to test some aspects of optimal sex allocation theory. Both populations fit all the predictions of the models of Green and Brockmann and Grafen. Maternal provisions determined the size of each offspring, and females allocated well-stocked brood cells to daughters, the sex that benefits most being large. This strategy resulted in a difference in size between the sexes. In São Carlos, female weight at emergence was 1.18 times that of males, in Luís Antônio this value was 1.13. The brood cell volume was correlated with both wing length and weight at emergence in both sexes, and the chance that a given brood cell contained a male offspring decreased with increased brood cell volume. In T. rogenhoferi female body size was related to fitness. Larger females were able to collect more mass of spiders per day, the spiders they captured were heavier, and they provisioned more brood cells per day. They also produced larger daughters. For males, no relationship between body size and fitness was found, but the data were scarce. Since the patterns of provisioning were variable among different females in both study sites, it is possible that the females not follow a unique strategy for sex allocation. The sex ratio and/or investment ratio in the São Carlos population was female-biased and in Luís Antônio, male-biased. In spite of the influence of trap-nests diameters on male production in Luís Antônio, there is some evidence that in São Carlos population the local availability of prey and/or lower rate of parasitism may be major forces in determining the observed sex ratio, but further studies are necessary to verify such hypothesis.

Cervical cancer screening in rural South Africa among HIV-infected migrant farm workers and sex workers.

Science.gov (United States)

Afzal, Omara; Lieber, Molly; Dottino, Peter; Beddoe, Ann Marie

2017-05-01

At an HIV clinic in the Limpopo province of South Africa, chart reviews revealed long delays in addressing abnormal Pap smears, difficulty in referrals, poor quality and lost results, and increasing cases of cervical cancer. To address these barriers, a "see and treat" approach to screening was proposed. The objective was to integrate this method into current HIV care offered by local providers and to obtain demographic and risk factor data for use in future educational and intervention programs in the region. A cross sectional study of HIV farm workers and at-risk sex workers attending an HIV clinic was performed with visual inspection with acetic acid (VIA). Those with positive screens were offered cryotherapy. Clinic charts were reviewed retrospectively for Pap smear results for the previous year at the time of program initiation and at 12 and 18 months post-program. A total of 403 participants consented and underwent screening with VIA (306 Farm workers and 97 sex workers participated). 83.9% of participants (32.9% sex workers and 100% farm workers) were HIV +. VIA was positive in 30.5% of participants, necessitating cryotherapy. There was no significant difference in VIA positivity between HIV + farm workers and sex workers. There was a positive correlation between Pap smears and VIAs results. We demonstrate successful integration of cervical cancer screening using VIA for HIV + farm workers and sex workers into an existing HIV treatment and prevention clinic in rural South Africa, addressing and treating abnormal results promptly.

Common understanding of Emergency Workers

International Nuclear Information System (INIS)

2015-11-01

While the protection of Emergency Workers is regulated in most countries, national definitions, respectively interpretations differ. The prevailing regulatory frameworks are: - Basic Safety Standards (2013/59/EURATOM) The Basis Safety Standards (BSS) are binding for members of the EU. The BSS give a definition of Emergency Workers. - IAEA General Safety Requirements Part 7 (Draft). The Agency's definition is consistent with the BSS-definition. In addition, the Helper is defined. - The Nordic Flag-book. The Nordic Flag-book's Emergency Worker is consistent with the BSS-definition. In addition, workers are defined. Flag-book-Workers (FBW) are neither coterminous with GSR-P-7-helpers nor with BSS-workers. The possible need for harmonization was assessed by the means of a questionnaire, asking members of the Working Group Emergencies to attribute regulatory categories to different roles that might arise in an emergency. While showing a rich variation in interpretations, there is general agreement for the most important roles. Wherever differences are found, the bilateral impact is deemed to be marginal at worst. Therefore, no need for harmonisation with respect to the concept of Emergency Workers is seen

76 FR 61741 - Bmc Software, Inc. Including On-Site Leased Workers From COMSYS ITS Including Remote Workers...

Science.gov (United States)

2011-10-05

... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-74,540] Bmc Software, Inc... November 23, 2010, applicable to workers of BMC Software, Inc., including on-site leased workers from... BMC Software, inc., including on-site leased workers from Comsys ITS, and including remote workers...

Improving Emergency Management by Modeling Ant Colonies

Science.gov (United States)

2015-03-01

perform functions such as nursing the brood or maintaining the nest. The more mature workers will begin to travel outside the nest to perform foraging...small sized ants predominantly act in functional roles such as nurses or transport services within the nest. The larger sizes predominantly function...stages: the founding stage, the ergonomic stage, and the reproductive stage. The founding stage is marked by a queen ant successful mating and laying

Workers' marginal costs of commuting

DEFF Research Database (Denmark)

van Ommeren, Jos; Fosgerau, Mogens

2009-01-01

This paper applies a dynamic search model to estimate workers' marginal costs of commuting, including monetary and time costs. Using data on workers' job search activity as well as moving behaviour, for the Netherlands, we provide evidence that, on average, workers' marginal costs of one hour...

75 FR 6031 - Policy Paper on Revised Risk Assessment Methods for Workers, Children of Workers in Agricultural...

Science.gov (United States)

2010-02-05

... and its relationship to several other key Agency initiatives that are currently under development and... Assessment Methods for Workers, Children of Workers in Agricultural Fields, and Pesticides with No Food Uses... for comment a policy paper entitled ``Revised Risk Assessment Methods for Workers, Children of Workers...

Physiology of reproductive worker honey bees (Apis mellifera): insights for the development of the worker caste.

Science.gov (United States)

Peso, Marianne; Even, Naïla; Søvik, Eirik; Naeger, Nicholas L; Robinson, Gene E; Barron, Andrew B

2016-02-01

Reproductive and behavioural specialisations characterise advanced social insect societies. Typically, the honey bee (Apis mellifera) shows a pronounced reproductive division of labour between worker and queen castes, and a clear division of colony roles among workers. In a queenless condition, however, both of these aspects of social organisation break down. Queenless workers reproduce, forage and maintain their colony operating in a manner similar to communal bees, rather than as an advanced eusocial group. This plasticity in social organisation provides a natural experiment for exploring physiological mechanisms of division of labour. We measured brain biogenic amine (BA) levels and abdominal fat body vitellogenin gene expression levels of workers in queenright and queenless colonies. Age, ovary activation and social environment influenced brain BA levels in honey bees. BA levels were most influenced by ovary activation state in queenless bees. Vitellogenin expression levels were higher in queenless workers than queenright workers, but in both colony environments vitellogenin expression was lower in foragers than non-foragers. We propose this plasticity in the interacting signalling systems that influence both reproductive and behavioural development allows queenless workers to deviate significantly from the typical worker bee reaction norm and develop as reproductively active behavioural generalists.

Short communication. First field assessment of Bacillus thuringiensis subsp. kurstaki aerial application on the colony performance of Apis mellifera L. (Hymenoptera: Apidae

Directory of Open Access Journals (Sweden)

Maria del Mar Leza Salord

2014-05-01

Full Text Available Honeybee populations around the world are experiencing a decrease in colony numbers probably due to a combination of different causes, such as diseases, poor nutrition and frequent applications of insecticides to control pests. Previous studies about the effect of pesticide Bacillus thuringiensis subsp. kurstaki (Btk on Apis mellifera L. report different results. The aim of this study was to analyze the effect of field aerial applications of Btk on bee colony performance, specifically on the brood cell percentage evolution, which can be used as an indicator of queen health and brood development breeding rates. To achieve it, the brood cell surface was photographed in every sampling, and data were analyzed using a method based on image treatment software. A total of 480 pictures were examined from two groups of four nucleus hives in two areas, one receiving aerial spraying with Btk and the other without treatment. A mixed factorial design was realized to analyse the data showing no differences in colony performance between the two groups of colonies either before the treatment, during and at the end of the assay. Furthermore, the brood surface ratio of Btk-treated/untreated increased along the experiment. Therefore, the results of the present study suggest that Btk aerial applications did not affect the brood development of honeybees under natural conditions. Nevertheless further field studies are required to ascertain a safe use of Btk in forest pest management.

Possible health effects of liquefied petroleum gas on workers at filling and distribution stations of Gaza governorates.

Science.gov (United States)

Sirdah, M M; Al Laham, N A; El Madhoun, R A

2013-03-01

Liquefied petroleum gas (LPG) is widely used in the Gaza Strip for domestic purposes, in agriculture and industry and, illegally, in cars. This study aimed to identify possible health effects on workers exposed to LPG in Gaza governorates. Data were collected by a questionnaire interview, and haematological and biochemical analyses of venous blood samples were made from 30 workers at filling and distribution stations and 30 apparently healthy controls. Statistically significant differences were found in all self-reported health-related complaints among LPG workers versus controls. LPG workers had significantly higher values of red blood cell counts, haemoglobin, haematocrit mean corpuscular haemoglobin and platelet counts. They also had significantly higher values of kidney function tests (urea, creatinine and uric acid) and liver function enzyme activities (aspartate aminotransferase and alanine aminotransferase). LPG workers at Gaza Strip petroleum stations are at higher risk for health-related symptoms and clinical abnormalities.

Innovative Older-Worker Programs.

Science.gov (United States)

Jessup, Denise; Greenberg, Barbara

1989-01-01

Describes program innovations to keep older workers employed: retraining, job sharing, flexible working hours, job redesign, and phased retirement. Addresses costs and savings, disincentives for workers and employers, and future trends. (SK)

Cell provisioning and oviposition in Melipona beecheii (Apidae, Meliponinae),with a note on caste determination

NARCIS (Netherlands)

Veen, Johan Wilhelm van

1999-01-01

We examined the food provisioning and oviposition process (POP) for worker- and gyne-producing cells of Melipona beecheii. POPs for both castes did not differ significantly in duration and number of trophic eggs oviposited by workers in the cells. The frequency of food discharges by workers in

Retention of health workers in Malawi: perspectives of health workers and district management.

Science.gov (United States)

Manafa, Ogenna; McAuliffe, Eilish; Maseko, Fresier; Bowie, Cameron; MacLachlan, Malcolm; Normand, Charles

2009-07-28

Shortage of human resources is a major problem facing Malawi, where more than 50% of the population lives in rural areas. Most of the district health services are provided by clinical health officers specially trained to provide services that would normally be provided by fully qualified doctors or specialists. As this cadre and the cadre of enrolled nurses are the mainstay of the Malawian health service at the district level, it is important that they are supported and motivated to deliver a good standard of service to the population. This study explores how these cadres are managed and motivated and the impact this has on their performance. A quantitative survey measured health workers' job satisfaction, perceptions of the work environment and sense of justice in the workplace, and was reported elsewhere. It emerged that health workers were particularly dissatisfied with what they perceived as unfair access to continuous education and career advancement opportunities, as well as inadequate supervision. These issues and their contribution to demotivation, from the perspective of both management and health workers, were further explored by means of qualitative techniques.Focus group discussions were held with health workers, and key-informant interviews were conducted with members of district health management teams and human resource officers in the Ministry of Health. The focus groups used convenience sampling that included all the different cadres of health workers available and willing to participate on the day the research team visited the health facility. The interviews targeted district health management teams in three districts and the human resources personnel in the Ministry of Health, also sampling those who were available and agreed to participate. The results showed that health workers consider continuous education and career progression strategies to be inadequate. Standard human resource management practices such as performance appraisal and the

Retention of health workers in Malawi: perspectives of health workers and district management

Directory of Open Access Journals (Sweden)

MacLachlan Malcolm

2009-07-01

Full Text Available Abstract Background Shortage of human resources is a major problem facing Malawi, where more than 50% of the population lives in rural areas. Most of the district health services are provided by clinical health officers specially trained to provide services that would normally be provided by fully qualified doctors or specialists. As this cadre and the cadre of enrolled nurses are the mainstay of the Malawian health service at the district level, it is important that they are supported and motivated to deliver a good standard of service to the population. This study explores how these cadres are managed and motivated and the impact this has on their performance. Methods A quantitative survey measured health workers' job satisfaction, perceptions of the work environment and sense of justice in the workplace, and was reported elsewhere. It emerged that health workers were particularly dissatisfied with what they perceived as unfair access to continuous education and career advancement opportunities, as well as inadequate supervision. These issues and their contribution to demotivation, from the perspective of both management and health workers, were further explored by means of qualitative techniques. Focus group discussions were held with health workers, and key-informant interviews were conducted with members of district health management teams and human resource officers in the Ministry of Health. The focus groups used convenience sampling that included all the different cadres of health workers available and willing to participate on the day the research team visited the health facility. The interviews targeted district health management teams in three districts and the human resources personnel in the Ministry of Health, also sampling those who were available and agreed to participate. Results The results showed that health workers consider continuous education and career progression strategies to be inadequate. Standard human resource

A trial of a job-specific workers' health surveillance program for construction workers: study protocol

NARCIS (Netherlands)

Boschman, J.S.; van der Molen, H.F.; van Duivenbooden, C.; Sluiter, J.K.; Frings-Dresen, M.H.W.

2011-01-01

Dutch construction workers are offered periodic health examinations. This care can be improved by tailoring this workers health surveillance (WHS) to the demands of the job and adjust the preventive actions to the specific health risks of a worker in a particular job. To improve the quality of the

Preventive actions taken by workers after workers' health surveillance: a controlled trial

NARCIS (Netherlands)

Boschman, J. S.; van der Molen, H. F.; Frings-Dresen, M. H. W.; Sluiter, J. K.

2013-01-01

To evaluate construction workers' preventive actions and occupational physician's (OPs) recommendations after a job-specific workers' health surveillance (WHS) compared with the currently used generic WHS. After the WHS, the OPs' written recommendations were captured. At the 3-month follow-up, the

Process Evaluation of a Workers' Health Surveillance Program for Meat Processing Workers

NARCIS (Netherlands)

van Holland, Berry J; Brouwer, Sandra; de Boer, Michiel R; Reneman, Michiel F; Soer, Remko

2017-01-01

Objective To evaluate the implementation process of a workers' health surveillance (WHS) program in a Dutch meat processing company. Methods Workers from five plants were eligible to participate in the WHS program. The program consisted of four evaluative components and an intervention component.

Process Evaluation of a Workers' Health Surveillance Program for Meat Processing Workers

NARCIS (Netherlands)

van Holland, Berry; Brouwer, Sandra; de Boer, Michiel R; Reneman, Michiel F; Soer, Remko

Objective To evaluate the implementation process of a workers' health surveillance (WHS) program in a Dutch meat processing company. Methods Workers from five plants were eligible to participate in the WHS program. The program consisted of four evaluative components and an intervention component.

Comparing Social Worker and Non-Social Worker Outcomes: A Research Review

Science.gov (United States)

Rubin, Allen; Parrish, Danielle E.

2012-01-01

This article reports on a review of the literature comparing the outcomes of social workers with those of non-social workers. The review was commissioned by NASW's Texas Chapter to examine empirical evidence regarding the comparative effectiveness of social work to possibly support efforts to educate employers and the public about the value of…

Radon exposure, chromosomal aberrations, and genetic polymorphisms in selected Slovak cave workers

International Nuclear Information System (INIS)

Musak, L.; Pec, M.; Vicanova, M.; Vodicka, P.; Hanova, M.; Buchancova, J.; Moravcikova, K.; Klimentova, G.; Vodickova, L.

2005-01-01

The aim of work was genotoxic risk assessment of the Slovak show cave workers employed by the Slovak Caves Administration in Liptovsky Mikulas. They are guides or administrators of the four Slovak show caves: Vazecka, Demanovska, Bystrianska, and Harmanecka. We examined 51 workers exposed to radon, with average age 35.64 years ± 6.63 (SD) and average exposition time 9.78 years ± 6.27 (SD). They are 43 men (i.e. 84.31 %) and 9 women (i.e. 15.69 %). The control group consisted of 32 healthy workers from Faculty Hospital in Martin. The workers were not exposed to any genotoxic agents. The average age is 31.84 years ± 5.84(SD). From every subject we evaluated 100 mitosis, i.e. 5100 mitosis from exposed workers and 3200 mitosis from control subjects. In exposed group we found in 111 cells chromosomal aberrations, this present 2.18 % Ab.c. ± 0.19 (SEM), and in control 1 st group 1.53 % ± 0.16 (SEM). There are 106 breaks (95.50%), and 5 exchanges (4.50%) on chromosomes. The highest number of Ab.c. we detected in workers of Vazecka (2.63 % Ab.c) and Bystrianska (2.00 % Ab.c.) caves. There is a significant increase (P < 0.05) in the mean number of Ab.c. in workers of cave Vazecka as compared to control. In 15 cases (i.e. 28.30 %) we found increase or high exposure to genotoxic agents, we found any difference between sex, and any dependence of the number of Ab.c. on age and time of exposure. The Vazecka cave workers showed three times higher mean effective doses all the year round (milliSievert) than workers additional caves. The measured values of radiation in the caves and mines exceeded the permissible limits and Regional Hygienist of the Central Slovakia declared in 1981 the risk zones and, at the same time, the monitoring of working atmosphere was initiated. Our evaluations referred to certain exposition of this carcinogen in cave workers too. The essence of prevention is based in the lowering of ionizing radiation and improvement of the sanitary