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Sample records for worker brood cells

  1. Behavior of varroa mites in worker brood cells of Africanized honey bees.

    Science.gov (United States)

    Calderón, Rafael A; Fallas, Natalia; Zamora, Luis G; van Veen, Johan W; Sánchez, Luis A

    2009-12-01

    The ectoparasitic mite Varroa destructor is currently the most important pest of the honey bee, Apis mellifera. Because mite reproduction occurs within the sealed cell, the direct observation of varroa activity inside the cell is difficult. A video observation method using transparent polystyrol cells containing infested brood was used to analyze the behavior of varroa mites in worker brood of Africanized honey bees. We recorded how mites feed on the larva and pupa, construct a fecal accumulation site and how the bee larva carried out some longitudinal movements around the cell. The feeding activity of the foundress mite varies during the course of the cycle. On the prepupa mites were found to feed often (0.3 +/- 0.2 bouts h(-1)) for a period of 8.7 +/- 8.4 min h(-1) and there was no preference for a specific segment as feeding site. On the opposite, during the pupal stage mites fed less often (0.1 +/- 0.1 bouts h(-1)) for a period of 6.2 +/- 4.0 min h(-1) and almost always at a particular site (92.4%). On pupa, 83.7% of the feeding was on the 2nd abdominal segment (n = 92), and only few perforations were found on the thorax. Varroa shows a preference for defecation in the posterior part of the cell (cell apex), close to the bee's anal zone. We found a high correlation between the position of the feeding site on the pupa and the position of the fecal accumulation on the cell wall. Most infested cells have only one fecal accumulation site and it was the favorite resting site for the mite, where it spent 24.3 +/- 3.9 min h(-1). Longitudinal displacements were observed in 28.0% (n = 25) of the analyzed bee larvae. Turning movements around the cell, from the bottom to the top, were carried out by these larvae, mainly during the second day (47.7 +/- 22.5 min h(-1)), just before pupation, with a total time of 874.9 +/- 262.2 min day(-1) (n = 7 individuals). These results in worker brood of Africanized bees demonstrate adaptations of varroa mites to parasitizing the

  2. Reproduction of Varroa destructor and offspring mortality in worker and drone brood cells of Africanized honey bees.

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    Calderón, R A; Ureña, S; van Veen, J W

    2012-04-01

    Varroa destructor is known to be the most serious parasite of Apis mellifera worldwide. In order to reproduce varroa females enter worker or drone brood shortly before the cell is sealed. From March to December 2008, the reproductive rate and offspring mortality (mature and immature stages), focusing on male absence and male mortality of V. destructor, was investigated in naturally infested worker and drone brood of Africanized honey bees (AHB) in Costa Rica. Data were obtained from 388 to 403 single infested worker and drone brood cells, respectively. Mite fertility in worker and drone brood cells was 88.9 and 93.1%, respectively. There was no difference between the groups (X(2) = 3.6, P = 0.06). However, one of the most significant differences in mite reproduction was the higher percentage of mites producing viable offspring in drone cells (64.8%) compared to worker cells (37.6%) (X(2) = 57.2, P drone cells was high in the protonymph stage (mobile and immobile). A significant finding was the high rate of male mortality. The worker and drone brood revealed that 23.9 and 6.9%, respectively, of the adult male offspring was found dead. If the absence (missing) of the male and adult male mortality are taken together the percentage of cells increased to 40.0 and 21.3% in worker and drone cells, respectively (X(2) = 28.8, P < 0.05). The absence of the male or male mortality in a considerable number of worker cells naturally infested with varroa is the major factor in our study which reduces the production of viable daughters in AHB colonies in Costa Rica.

  3. Drone and Worker Brood Microclimates Are Regulated Differentially in Honey Bees, Apis mellifera.

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    Li, Zhiyong; Huang, Zachary Y; Sharma, Dhruv B; Xue, Yunbo; Wang, Zhi; Ren, Bingzhong

    2016-01-01

    Honey bee (Apis mellifera) drones and workers show differences in morphology, physiology, and behavior. Because the functions of drones are more related to colony reproduction, and those of workers relate to both survival and reproduction, we hypothesize that the microclimate for worker brood is more precisely regulated than that of drone brood. We assessed temperature and relative humidity (RH) inside honey bee colonies for both drone and worker brood throughout the three-stage development period, using digital HOBO® Data Loggers. The major findings of this study are that 1) both drone and worker castes show the highest temperature for eggs, followed by larvae and then pupae; 2) temperature in drones are maintained at higher precision (smaller variance) in drone eggs and larvae, but at a lower precision in pupae than the corresponding stages of workers; 3) RH regulation showed higher variance in drone than workers across all brood stages; and 4) RH regulation seems largely due to regulation by workers, as the contribution from empty honey combs are much smaller compared to that from adult workers. We conclude that honey bee colonies maintain both temperature and humidity actively; that the microclimate for sealed drone brood is less precisely regulated than worker brood; and that combs with honey contribute very little to the increase of RH in honey bee colonies. These findings increase our understanding of microclimate regulation in honey bees and may have implications for beekeeping practices.

  4. Varroa Sensitive Hygiene and Drone Brood

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    Honey bees have been bred to express high levels of varroa sensitive hygiene (VSH), which is the removal of mite-infested pupae from capped worker brood. This hygienic behavior is a complex interaction of bees and brood in which brood cells sometimes are inspected, and then brood is either removed (...

  5. The reproductive ability of Varroa destructor in worker brood of Africanized and hybrid honey bees in Costa Rica

    NARCIS (Netherlands)

    Calderon, R.A.; Sommeijer, M.J.; Ruijter, de A.; Veen, van der J.W.

    2003-01-01

    From February to July 2001, the reproductive ability of Varroa destructor in artificially infested worker brood cells of Africanized honey bees (AHB) (Apis mellifera) and hybrids (HF1) of AHB x European honey bees was investigated in Costa Rica. No significant differences were found between AHB and

  6. Nurse honeybee workers tend capped brood, which does not require feeding, around the clock.

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    Nagari, Moshe; Brenner, Yafit; Bloch, Guy

    2017-11-15

    'Nurse' honeybees tend brood around the clock with attenuated or no circadian rhythms, but the brood signals inducing this behavior remain elusive. We first tested the hypothesis that worker circadian rhythms are regulated by brood pheromones. We monitored locomotor activity of individually isolated nurse bees that were exposed to either various doses of larval extract or synthetic brood ester pheromone (BEP). Bees orally treated with larval extract showed attenuated circadian rhythms in one of four tested colonies; a similar but statistically non-significant trend was seen in two additional colonies. Nurse bees treated with synthetic BEP showed rhythm attenuation in one of three tested colonies. Next, we tested the hypothesis that capped brood, which does not require feeding, nevertheless induces around-the-clock activity in nurses. By combining a new protocol that enables brood care by individually isolated nurse bees, detailed behavioral observations and automatic high-resolution monitoring of locomotor activity, we found that isolated nurses tended capped brood around the clock with attenuated circadian rhythms. Bees individually isolated in similar cages but without brood showed strong circadian rhythms in locomotor activity and rest. This study shows for the first time that the need to feed hungry larvae is not the only factor accounting for around-the-clock activity in nurse bees. Our results further suggest that the transition between activity with and without circadian rhythms is not a simple switch triggered by brood pheromones. Around-the-clock tending may enhance brood development and health in multiple ways that include improved larval feeding, thermoregulation or hygienic behavior. © 2017. Published by The Company of Biologists Ltd.

  7. Selecting honey bees for worker brood that reduces the reproduction of Varroa destructor

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    We investigated an effect of Apis mellifera worker brood on the reproduction of Varroa destructor as a resistance trait by conducting seven generations of bidirectional selection. Initial tests showed two-fold differences in mite fecundity (progeny per foundress mites) between colonies of different...

  8. Sub-lethal effects of pesticide residues in brood comb on worker honey bee (Apis mellifera development and longevity.

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    Judy Y Wu

    Full Text Available BACKGROUND: Numerous surveys reveal high levels of pesticide residue contamination in honey bee comb. We conducted studies to examine possible direct and indirect effects of pesticide exposure from contaminated brood comb on developing worker bees and adult worker lifespan. METHODOLOGY/PRINCIPAL FINDINGS: Worker bees were reared in brood comb containing high levels of known pesticide residues (treatment or in relatively uncontaminated brood comb (control. Delayed development was observed in bees reared in treatment combs containing high levels of pesticides particularly in the early stages (day 4 and 8 of worker bee development. Adult longevity was reduced by 4 days in bees exposed to pesticide residues in contaminated brood comb during development. Pesticide residue migration from comb containing high pesticide residues caused contamination of control comb after multiple brood cycles and provided insight on how quickly residues move through wax. Higher brood mortality and delayed adult emergence occurred after multiple brood cycles in contaminated control combs. In contrast, survivability increased in bees reared in treatment comb after multiple brood cycles when pesticide residues had been reduced in treatment combs due to residue migration into uncontaminated control combs, supporting comb replacement efforts. Chemical analysis after the experiment confirmed the migration of pesticide residues from treatment combs into previously uncontaminated control comb. CONCLUSIONS/SIGNIFICANCE: This study is the first to demonstrate sub-lethal effects on worker honey bees from pesticide residue exposure from contaminated brood comb. Sub-lethal effects, including delayed larval development and adult emergence or shortened adult longevity, can have indirect effects on the colony such as premature shifts in hive roles and foraging activity. In addition, longer development time for bees may provide a reproductive advantage for parasitic Varroa destructor

  9. The activity of carbohydrate-degrading enzymes in the development of brood and newly emerged workers and drones of the Carniolan honeybee, Apis mellifera carnica.

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    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 sexes of brood; high activity was found in unsealed larvae, the lowest in prepupae followed by an increase in enzymatic activity. Especially intensive increases in activity occurred in the last stage of pupae and newly emerged imago. Besides α-amylase, the activities of other enzymes were higher in drone than in worker broods. Among drones, activity of glucoamylase was particularly high, ranging from around three times higher in the youngest larvae to 13 times higher in the oldest pupae. This confirms earlier suggestions about higher rates of metabolism in drone broods than in worker broods.

  10. Invasion of Varroa mites into honey bee brood cells

    NARCIS (Netherlands)

    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

  11. 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

    2015-06-01

    Full Text Available 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, trehalose, maltotriose, fructose, and glucose were estimated. The correlations between sugar content and the activity of the main hydrolases of carbohydrate metabolism - α-amylase, glucoamylase, trehalase, maltase, and sucrase - were determined. The addition of vitamin C to the diet of wintering bees did not impair their sugar metabolism. Vitamin C supplements exerted a positive effect by significantly increasing glycogen and trehalose concentrations in the initial phase of development and in newly emerged workers. Vitamin C did not induce significant changes in the developmental profile of carbohydrate degrading enzymes, except for the earliest stage of larval development when enzyme activity levels were below those noted in the control group.

  12. Africanized honey bees (Apis mellifera L. are more efficient at removing worker brood artificially infested with the parasitic mite Varroa jacobsoni Oudemans than are Italian bees or Italian/Africanized hybrids

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    José Carlos Vieira Guerra Jr.

    2000-03-01

    Full Text Available Africanized honey bees are more tolerant of infestations with the mite Varroa jacobsoni than are honey bees of European origin. The capacity of these bees to detect and react to brood infested with this mite could be one of the factors determining this tolerance. We tested colonies of Africanized bees headed by queens from swarms collected in Ribeirão Preto, São Paulo State. The Italian colonies had queens imported directly from the USA, or from the Brazilian Island of Fernando de Noronha, where varroa-infested Italian colonies have been maintained, untreated, since 1984. Recently sealed worker brood cells were artificially infested by opening the cell capping, inserting live adult female mites and resealing the cells. Control cells were treated in the same way, but without introducing mites. The ability of the Africanized honey bees to recognize and remove this artificially infested brood was compared with that of first generation Italian/Africanized hybrid bees, and with the two groups of "pure" Italian bees, in three separate experiments. Africanized colonies removed a mean of 51% of the infested brood, while Italian/Africanized hybrid colonies removed 25%. Africanized colonies also removed a significantly greater proportion of infested brood than did Italian colonies, headed by queens from the USA (59 vs. 31%, respectively. Similarly, when Africanized colonies were compared with colonies of Italian bees from Fernando de Noronha, the former were found to be significantly more efficient at removing infested brood (61 vs. 35%, respectively, even though the population of Italian bees on this island has been exposed to and survived varroa infestations (without treatment for more than 12 years. Only the Africanized honey bees removed a significant proportion of varroa-infested brood, when the data was corrected for brood removal from control cells.Abelhas africanizadas são mais tolerantes à infestação com o ácaro Varroa jacobsoni do que

  13. 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.

  14. Specificity in chemical profiles of workers, brood and mutualistic fungi in Atta, Acromyrmex, and Sericomyrmex fungus-growing ants

    DEFF Research Database (Denmark)

    Richard, Freddie-Jeanne; Poulsen, Michael; Drijfhout, Falko

    2007-01-01

    Neotropical attine ants live in obligatory symbiosis with a fungus that they grow for food on a substrate of primarily plant material harvested by workers. Nestmate recognition is likely based on chemical cues as in most other social insects, but recent studies have indicated that both the ants...... attine ants: Atta colombica, Acromyrmex echinatior, and Sericomyrmex amabilis. The relative proportions of identified compounds were compared and represented 11 classes: n-alkanes, alkenes, branched methylalkanes, branched dimethylalkanes, trimethylalkanes, branched alkenes, aldehydes, alcohols, acetates...... compounds being derived from the ants, the ant brood, or the fungal symbiont are discussed. We hypothesize that hydrocarbons are particularly important as recognition cues because they appear to simultaneously allow the assessment of developmental stages and the identification of symbiont, colony...

  15. Molecular genetic analysis of Varroa destructor mites in brood, fallen injured mites and worker bee longevity in honey bees

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    Two important traits that contribute to honey bee (Apis mellifera) colony survival are resistance to Varroa destructor and longevity of worker bees. We investigated the relationship between a panel of single nucleotide polymorphism (SNP) markers and three phenotypic measurements of colonies: a) perc...

  16. Standard methods for fungal brood disease research

    DEFF Research Database (Denmark)

    Jensen, Annette Bruun; Aronstein, Kathrine; Manuel Flores, Jose

    2013-01-01

    Chalkbrood and stonebrood are two fungal diseases associated with honey bee brood. Chalkbrood, caused by Ascosphaera apis, is a common and widespread disease that can result in severe reduction of emerging worker bees and thus overall colony productivity. Stonebrood is caused by Aspergillus spp. ...

  17. 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.

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

    National Research Council Canada - National Science Library

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

    2014-01-01

    ... (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...

  19. 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.

  20. [ATPase and phosphatase activity of drone brood].

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    Bodnarchuk, L I; Stakhman, O S

    2004-01-01

    Most researches on insect enzymes concern carbohydrate and nitrogenous exchange. Data on ATPase activity for larval material of drone brood are absent in the available literature. The drone brood is one of the least investigated apiproducts. Allowing for the important role of ATPase in the vital functions of the insect cells our work was aimed at the study of ATPase of the drone blood activity and that of alkaline and acid phosphatases. When studying liophylised preparations of the drone brood homogenate we have found out high activity of Mg2+, Na+, K+-, Ca2+- and Mg2+-ATPase and of alkaline and acid phosphatase, that is the possible explanation of the high-intensity power and plastic processes proceeding during growth and development of larvae.

  1. Ant brood function as life preservers during floods.

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    Jessica Purcell

    Full Text Available Social organisms can surmount many ecological challenges by working collectively. An impressive example of such collective behavior occurs when ants physically link together into floating 'rafts' to escape from flooded habitat. However, raft formation may represent a social dilemma, with some positions posing greater individual risks than others. Here, we investigate the position and function of different colony members, and the costs and benefits of this functional geometry in rafts of the floodplain-dwelling ant Formica selysi. By causing groups of ants to raft in the laboratory, we observe that workers are distributed throughout the raft, queens are always in the center, and 100% of brood items are placed on the base. Through a series of experiments, we show that workers and brood are extremely resistant to submersion. Both workers and brood exhibit high survival rates after they have rafted, suggesting that occupying the base of the raft is not as costly as expected. The placement of all brood on the base of one cohesive raft confers several benefits: it preserves colony integrity, takes advantage of brood buoyancy, and increases the proportion of workers that immediately recover after rafting.

  2. Ant brood function as life preservers during floods.

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    Purcell, Jessica; Avril, Amaury; Jaffuel, Geoffrey; Bates, Sarah; Chapuisat, Michel

    2014-01-01

    Social organisms can surmount many ecological challenges by working collectively. An impressive example of such collective behavior occurs when ants physically link together into floating 'rafts' to escape from flooded habitat. However, raft formation may represent a social dilemma, with some positions posing greater individual risks than others. Here, we investigate the position and function of different colony members, and the costs and benefits of this functional geometry in rafts of the floodplain-dwelling ant Formica selysi. By causing groups of ants to raft in the laboratory, we observe that workers are distributed throughout the raft, queens are always in the center, and 100% of brood items are placed on the base. Through a series of experiments, we show that workers and brood are extremely resistant to submersion. Both workers and brood exhibit high survival rates after they have rafted, suggesting that occupying the base of the raft is not as costly as expected. The placement of all brood on the base of one cohesive raft confers several benefits: it preserves colony integrity, takes advantage of brood buoyancy, and increases the proportion of workers that immediately recover after rafting.

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

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    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.

  4. Nest enlargement in leaf-cutting ants: relocated brood and fungus trigger the excavation of new chambers.

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    Daniela Römer

    Full Text Available During colony growth, leaf-cutting ants enlarge their nests by excavating tunnels and chambers housing their fungus gardens and brood. Workers are expected to excavate new nest chambers at locations across the soil profile that offer suitable environmental conditions for brood and fungus rearing. It is an open question whether new chambers are excavated in advance, or will emerge around brood or fungus initially relocated to a suitable site in a previously-excavated tunnel. In the laboratory, we investigated the mechanisms underlying the excavation of new nest chambers in the leaf-cutting ant Acromyrmex lundi. Specifically, we asked whether workers relocate brood and fungus to suitable nest locations, and to what extent the relocated items trigger the excavation of a nest chamber and influence its shape. When brood and fungus were exposed to unfavorable environmental conditions, either low temperatures or low humidity, both were relocated, but ants clearly preferred to relocate the brood first. Workers relocated fungus to places containing brood, demonstrating that subsequent fungus relocation spatially follows the brood deposition. In addition, more ants aggregated at sites containing brood. When presented with a choice between two otherwise identical digging sites, but one containing brood, ants' excavation activity was higher at this site, and the shape of the excavated cavity was more rounded and chamber-like. The presence of fungus also led to the excavation of rounder shapes, with higher excavation activity at the site that also contained brood. We argue that during colony growth, workers preferentially relocate brood to suitable locations along a tunnel, and that relocated brood spatially guides fungus relocation and leads to increased digging activity around them. We suggest that nest chambers are not excavated in advance, but emerge through a self-organized process resulting from the aggregation of workers and their density

  5. Nest enlargement in leaf-cutting ants: relocated brood and fungus trigger the excavation of new chambers.

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    Römer, Daniela; Roces, Flavio

    2014-01-01

    During colony growth, leaf-cutting ants enlarge their nests by excavating tunnels and chambers housing their fungus gardens and brood. Workers are expected to excavate new nest chambers at locations across the soil profile that offer suitable environmental conditions for brood and fungus rearing. It is an open question whether new chambers are excavated in advance, or will emerge around brood or fungus initially relocated to a suitable site in a previously-excavated tunnel. In the laboratory, we investigated the mechanisms underlying the excavation of new nest chambers in the leaf-cutting ant Acromyrmex lundi. Specifically, we asked whether workers relocate brood and fungus to suitable nest locations, and to what extent the relocated items trigger the excavation of a nest chamber and influence its shape. When brood and fungus were exposed to unfavorable environmental conditions, either low temperatures or low humidity, both were relocated, but ants clearly preferred to relocate the brood first. Workers relocated fungus to places containing brood, demonstrating that subsequent fungus relocation spatially follows the brood deposition. In addition, more ants aggregated at sites containing brood. When presented with a choice between two otherwise identical digging sites, but one containing brood, ants' excavation activity was higher at this site, and the shape of the excavated cavity was more rounded and chamber-like. The presence of fungus also led to the excavation of rounder shapes, with higher excavation activity at the site that also contained brood. We argue that during colony growth, workers preferentially relocate brood to suitable locations along a tunnel, and that relocated brood spatially guides fungus relocation and leads to increased digging activity around them. We suggest that nest chambers are not excavated in advance, but emerge through a self-organized process resulting from the aggregation of workers and their density-dependent digging behavior

  6. Specific Cues Associated With Honey Bee Social Defence against Varroa destructor Infested Brood.

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    Mondet, Fanny; Kim, Seo Hyun; de Miranda, Joachim R; Beslay, Dominique; Le Conte, Yves; Mercer, Alison R

    2016-05-03

    Social immunity forms an essential part of the defence repertoire of social insects. In response to infestation by the parasitic mite Varroa destructor and its associated viruses, honey bees (Apis mellifera L.) have developed a specific behaviour (varroa-sensitive hygiene, or VSH) that helps protect the colony from this parasite. Brood cells heavily infested with mites are uncapped, the brood killed, and the cell contents removed. For this extreme sacrifice to be beneficial to the colony, the targeting of parasitized brood for removal must be accurate and selective. Here we show that varroa-infested brood produce uniquely identifiable cues that could be used by VSH-performing bees to identify with high specificity which brood cells to sacrifice. This selective elimination of mite-infested brood is a disease resistance strategy analogous to programmed cell death, where young bees likely to be highly dysfunctional as adults are sacrificed for the greater good of the colony.

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

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    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

  8. Differences in sNPF receptor-expressing neurons in brains of fire ant (Solenopsis invicta Buren worker subcastes: indicators for division of labor and nutritional status?

    Directory of Open Access Journals (Sweden)

    Paula Castillo

    Full Text Available In the red imported fire ant, Solenopsis invicta Buren, the neuronal and molecular mechanisms related to worker division of labor are poorly understood. Workers from different subcastes (major, medium and minors perform different tasks, which are loosely associated with their size. We hypothesized that the short neuropeptide F (sNPF signaling system (NPY-like could be involved in mechanisms of worker division of labor and sensing or responding to colony nutritional requirements. Thus, we investigated the expression of the short neuropeptide F receptor (sNPFR in the brain and subesophageal ganglion (SEG of workers from colonies with and without brood. Across worker subcastes a total of 9 clusters of immunoreactive sNPFR cells were localized in the brain and the subesophageal ganglion (SEG; some of these cells were similar to those observed previously in the queen. Worker brain sNPFR cell clusters were found in the protocerebrum near mushroom bodies, in the central complex and in the lateral horn. Other sNPFR immunoreactive cells were found at the edge of the antennal lobes. Across subcastes, we observed both a constant and a differential pattern of sNPFR clusters, with a higher number of sNPFR cells found in minor than in major workers. Those sNPFR cells detected in all worker subcastes appear to be involved in olfaction or SEG functions. The differential expression of clusters in subcastes suggests that sNPFR signaling is involved in regulating behaviors associated with specific subcastes and thus, division of labor. Some sNPFR cells appear to be involved in nutrient sensing and/or brood care, feeding behavior and locomotion. In colonies without brood, workers showed a lower cluster number, and an overall reduced sNPFR signal. Our results suggest the sNPF signaling system is a candidate for the neurobiological control of worker division of labor and sensing brood presence, perhaps correlating with protein requirements and availability.

  9. Rearing Africanized honey bee (Apis mellifera L.) brood under laboratory conditions.

    Science.gov (United States)

    Silva, I C; Message, D; Cruz, C D; Campos, L A O; Sousa-Majer, M J

    2009-05-26

    We developed a method for rearing larvae of Africanized bees under laboratory conditions to determine the amount of diet needed during larval development to obtain a worker bee. We started with larvae 18-24 h old, which were transferred to polyethylene cell cups and fed for five days. We found that the amount of diet needed for successful larval development was: 4, 15, 25, 50, and 70 microl during the first to fifth days, respectively. The survival rate to the adult stage was 88.6% when the larvae received the daily amount of diet divided into two feedings, and 80% when they received only one feeding per day. The adult weight obtained in the laboratory, when the larvae received the daily amount of diet in a single dose, did not differ from those that were developed under field conditions (our control). All adults that we obtained in laboratory appeared to be normal. This technique has the potential to facilitate studies on brood pathogens, resistance mechanisms to diseases and also might be useful to test the impacts of transgenic products on honey bee brood.

  10. Testing predictions of small brood models using parasitoid wasps

    NARCIS (Netherlands)

    Guinnee, M.A.; Bernal, J.S.; Bezemer, T.M.; Fidgen, J.G.; Hardy, I.C.W.; Mayhew, P.J.; Mills, N.J.; West, S.A.

    2005-01-01

    Question: How is variation in offspring size (between broods) related to brood size? Hypotheses: Variance in offspring size (between broods) should decrease with increasing brood size as predicted by Charnov and colleagues' (Charnov and Downhower, 1995; Charnov et al., 1995) small brood invariant.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  13. Nuclear anomalies in the buccal cells of calcite factory workers.

    Science.gov (United States)

    Diler, Songül Budak; Ergene, Serap

    2010-04-01

    The micronucleus (MN) assay on exfoliated buccal cells is a useful and minimally invasive method for monitoring genetic damage in humans. To determine the genotoxic effects of calcite dust that forms during processing, MN assay was carried out in exfoliated buccal cells of 50 (25 smokers and 25 non-smokers) calcite factory workers and 50 (25 smokers and 25 non-smokers) age- and sex-matched control subjects. Frequencies of nuclear abnormalities (NA) other than micronuclei, such as binucleates, karyorrhexis, karyolysis and 'broken eggs', were also evaluated. Micronuclei and the other aforementioned anomalies were analysed by two way analysis of covariance. The linear correlations between the types of micronucleus and nuclear abnormalities were determined by Spearman's Rho. There was a positive correlation between micronuclei and other types of nuclear abnormalities in accordance with the Spearman's Rho test. Results showed statistically significant difference between calcite fabric workers and control groups. MN and NA frequencies in calcite fabric workers were significantly higher than those in control groups (p < 0.05). The results of this study indicate that calcite fabric workers are under risk of significant cytogenetic damage.

  14. Nuclear anomalies in the buccal cells of calcite factory workers

    Directory of Open Access Journals (Sweden)

    Songül Budak Diler

    2010-01-01

    Full Text Available The micronucleus (MN assay on exfoliated buccal cells is a useful and minimally invasive method for monitoring genetic damage in humans. To determine the genotoxic effects of calcite dust that forms during processing, MN assay was carried out in exfoliated buccal cells of 50 (25 smokers and 25 non-smokers calcite factory workers and 50 (25 smokers and 25 non-smokers age- and sex-matched control subjects. Frequencies of nuclear abnormalities (NA other than micronuclei, such as binucleates, karyorrhexis, karyolysis and 'broken eggs', were also evaluated. Micronuclei and the other aforementioned anomalies were analysed by two way analysis of covariance. The linear correlations between the types of micronucleus and nuclear abnormalities were determined by Spearman's Rho. There was a positive correlation between micronuclei and other types of nuclear abnormalities in accordance with the Spearman's Rho test. Results showed statistically significant difference between calcite fabric workers and control groups. MN and NA frequencies in calcite fabric workers were significantly higher than those in control groups (p < 0.05. The results of this study indicate that calcite fabric workers are under risk of significant cytogenetic damage.

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

    Science.gov (United States)

    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...

  16. Experimental late brood surveys: Southern Saskatchewan: 1991

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the late brood surveys for southern Saskatchewan during 1991. Survey methods, weather and habitat conditions, production indices, and tables...

  17. 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...

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  20. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  2. EFFECT OF BROOD STOCK SIZE ON EGG FERTILIZATION ...

    African Journals Online (AJOL)

    USER

    ABSTRACT. This experiment was conducted to investigate the effect of size of brood stock on egg fertilization, hatchability and fry survival rate of Clarias gariepinus in an intensive culture system, for a period of four weeks. Larger brood stock size (1200-1500g) produced larger eggs and bigger fry while moderate brood ...

  3. Regulation of oogenesis in honey bee workers via programed cell death.

    Science.gov (United States)

    Ronai, Isobel; Barton, Deborah A; Oldroyd, Benjamin P; Vergoz, Vanina

    2015-10-01

    Reproductive division of labour characterises eusociality. Currently little is known about the mechanisms that underlie the 'sterility' of the worker caste, but queen pheromone plays a major role in regulating the reproductive state. Here we investigate oogenesis in the young adult honey bee worker ovary in the presence of queen pheromone and in its absence. When queen pheromone is absent, workers can activate their ovaries and have well-developed follicles. When queen pheromone is present, even though workers have non-activated ovaries, they continually produce oocytes which are aborted at an early stage. Therefore, irrespective of the presence of the queen, the young adult worker ovary contains oocytes. By this means young workers retain reproductive plasticity. The degeneration of the germ cells in the ovarioles of workers in the presence of queen pheromone has the morphological hallmarks of programmed cell death. Therefore the mechanistic basis of 'worker sterility' relies in part on the regulation of oogenesis via programmed cell death. Our results suggest that honey bees have co-opted a highly conserved checkpoint at mid-oogenesis to regulate the fertility of the worker caste. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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

  6. Brood size and body condition in the House Sparrow Passer domesticus : the influence of brooding behaviour

    NARCIS (Netherlands)

    Chastel, O; Kersten, M.

    In many bird species, females undergo a marked decline in body condition during the first days of the nestling period. This decline may be because brooding young chicks reduces the time available for foraging. Alternatively, it might be viewed as an adaptive way to reduce flight costs when the food

  7. Marsupial brood care in Cretaceous tanaidaceans.

    Science.gov (United States)

    Sánchez-García, Alba; Delclòs, Xavier; Engel, Michael S; Bird, Graham J; Perrichot, Vincent; Peñalver, Enrique

    2017-06-29

    Parental care in animal evolution has long fascinated biologists, but tracing this complex of behavioural repertoires is challenging, as these transitory states often leave no corporeal traces as fossils. Among modern invertebrates, the tanaidaceans (Malacostraca: Peracarida), a lineage of marsupial crustaceans, show an interesting variety of brooding strategies. Here we report on fossil tanaidaceans from the Cretaceous of Spain and France that provide conclusive evidence for marsupial care of brood-offspring. Two exceptionally preserved female specimens of Alavatanais carabe and A. margulisae from Late Albian Peñacerrada I amber (Spain) possess four pairs of rudimentary oostegites, indicating formation of a marsupium. From Recent data, given the taxonomic distribution of a marsupium of four pairs of oostegites, we hypothesize that this may be plesiomorphic for the Tanaidomorpha. We also report on a peculiar tanaidacean specimen referable to the fossil family Alavatanaidae, Daenerytanais maieuticus gen. et sp. nov., from Early Cenomanian La Buzinie amber (France), preserved with its marsupial pouch and content. Our discoveries provide early evidence of the peracarid reproductive strategy, as seen in modern Tanaidacea, and argue that this form of parental care may have played a role in the diversification of the lineage during this period.

  8. Parental behaviour and mixed broods among cichlid fish of Lake ...

    African Journals Online (AJOL)

    It is suggested that all species which show well developed parental behaviour may have foreign fry mix with their broods on occasion. A variety of species of fry were found in mixed broods. These come from two categories of fish: those which apparently do not guard their free swimming fry; and those which have a well ...

  9. Three-dimensional visualisation of brooding behaviour in two ...

    African Journals Online (AJOL)

    Brooding in ophiuroids (Echinodermata: Ophiuroidea) is a highly-developed reproduction strategy and has evolved independently several times. In South African waters, brooding occurs both in the very small amphiurid Amphipholis squamata, which is hermaphroditic, and in the large ophiodermatid Ophioderma wahlbergii ...

  10. 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

  11. 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.

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

    Science.gov (United States)

    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.

  13. Elevated red blood cell distribution width and inflammation in printing workers.

    Science.gov (United States)

    Celik, Ahmet; Aydin, Neriman; Ozcirpici, Birgul; Saricicek, Edibe; Sezen, Hatice; Okumus, Mehmet; Bozkurt, Selim; Kilinc, Metin

    2013-11-15

    The aim of this study was to estimate the effects of exposure to chemical compounds on systemic biochemical inflammatory markers in printing industry workers. Fifty-eight printing workers from 19 different small- and medium-sized enterprises in the printing sector were investigated. For comparison, 80 healthy workers not subjected to workplace chemicals served as control subjects. No significant differences were observed between the printing workers and control subjects with respect to age, BMI, waist circumference/hip circumference ratio, smoking, and alcohol consumption. Printing workers had significantly higher serum TNF-alpha levels (11.02 ± 5.34 vs. 9.26 ± 3.87 pg/ml, p=0.039), plasma fibrinogen levels (1.74 ± 0.49 vs. 1.38 ± 0.5 mg/dl, p=0.012), and red blood cell distribution width (RDW-SD) (49.77 ± 3.09 vs. 47.3 ± 2.88 pprinting workers may be due to systemic toxic effects of chemical compounds used in this sector. TNF-alpha is an inflammatory cytokine that has a wide spectrum of biological activities, and fibrinogen plays an important role in pathological processes. Some compounds may be carcinogenic or mutagenic. Better designed workplaces and working conditions will help to reduce the hazardous effects of chemical compounds.

  14. Comparative Analysis of the Profitability in Brood-and-Sell and ...

    African Journals Online (AJOL)

    This study compared the profitability of brood-and-sell and brood-and-finish broiler enterprises in Abia State of Nigeria. Data collected using structured questionnaire and interview schedules from 70 poultry farmers made up of 35 brood-and-sell and 35 brood-and-finish broiler farmers were analyzed using multiple ...

  15. Micronuclei Frequencies and Nuclear Abnormalities in Oral Exfoliated Cells of Nuclear Power Plant Workers

    OpenAIRE

    Sagari, Shitalkumar G; Babannavar, Roopa; Lohra, Abhishek; Kodgi, Ashwin; Bapure, Sunil; Rao, Yogesh; J., Arun; Malghan, Manjunath

    2014-01-01

    Aim: Biomonitoring provides a useful tool to estimate the genetic risk from exposure to genotoxic agents. The aim of this study was to evaluate the frequencies of Micronuclei (MN) and other Nuclear abnormalities (NA) from exfoliated oral mucosal cells in Nuclear Power Station (NPS) workers.

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

    Science.gov (United States)

    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.

  17. 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

    2017-12-27

    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

  18. Whole cell biocatalysts: essential workers from Nature to the industry.

    Science.gov (United States)

    de Carvalho, Carla C C R

    2017-03-01

    Microorganisms have been exposed to a myriad of substrates and environmental conditions throughout evolution resulting in countless metabolites and enzymatic activities. Although mankind have been using these properties for centuries, we have only recently learned to control their production, to develop new biocatalysts with high stability and productivity and to improve their yields under new operational conditions. However, microbial cells still provide the best known environment for enzymes, preventing conformational changes in the protein structure in non-conventional medium and under harsh reaction conditions, while being able to efficiently regenerate necessary cofactors and to carry out cascades of reactions. Besides, a still unknown microbe is probably already producing a compound that will cure cancer, Alzeihmer's disease or kill the most resistant pathogen. In this review, the latest developments in screening desirable activities and improving production yields are discussed. © 2016 The Author. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  19. Role of anxiety and brooding in specificity of autobiographical recall.

    Science.gov (United States)

    Ricarte, Jorge Javier; Ros, Laura; Latorre, Jose Miguel; Muñoz, Maria Dolores; Aguilar, Maria Jose; Hernandez, Jose Vicente

    2016-12-01

    Overgeneral schemas and lack of autobiographical memory (AM) specificity about our past experiences can predict mood disturbance. Rumination, functional avoidance and executive processes are the main explanatory variables of such overgenerality. However, in non-clinical samples, rumination predicts overgenerality most consistently after the induction of dysphoric mood. Anxiety also activates rumination. Furthermore, anxiety predicts memory performance and has effects on mood which are independent of the effects of rumination. So, what might be the role of anxiety in autobiographical memory performance? A sample of 210 voluntary participants reported measures of autobiographical memory, anxiety, rumination (brooding and reflection), functional avoidance and executive functions (semantic and phonetic verbal fluency task). Autobiographical performance (specificity) was negatively associated with brooding and age and positively with phonetic verbal fluency but not with functional avoidance and anxiety. However, anxiety and brooding were positively correlated even after controlling for depression scores. Moreover, using structural equation modeling, anxiety showed a significant indirect effect on autobiographical specificity through brooding rumination. These results suggest a possible association of anxiety with autobiographical recall through brooding rumination. © 2016 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

  20. 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 <2% of volume on average from host eggs, whereas randomly paired eggs in random 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.

  1. 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

    Directory of Open Access Journals (Sweden)

    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.

  2. 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

  3. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  5. 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

  6. The benefit of large broods in barnacle geese : a study using natural and experimental manipulations

    NARCIS (Netherlands)

    Loonen, MJJE; Bruinzeel, Leo W.; Black, JM; Drent, RH

    1. In precocial birds, where the young feed themselves, the costs and benefits of brood size are still poorly understood. An experimental manipulation of brood size was employed to examine the effects of brood size on both parents and young in a wild population of barnacle geese [Branta leucopsis

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

    African Journals Online (AJOL)

    1994-06-06

    Jun 6, 1994 ... natural selection. Observations of brood release in several species of woodlice revealed that approximately 7% of females released between two and 10 young up to 24 h in advance of their siblings. Although under laboratory conditions oHspring fitness measures between precocious young and their ...

  8. Controlled Artificial Reproduction in Mouth Brooding Tilapia with ...

    African Journals Online (AJOL)

    A protocol for induced breeding in mouth brooding tilapia for genetic improvement is discussed. Human chorionic gonadotropin (HCG) was suspended in calcium free Hanks' balanced salt solution (c-f HBSS), and injected into the back muscle of blue tilapia (Oreochromis aureus) females at the dose of 0.5, 1.0 or 1.5 IU g-1 ...

  9. Supplementary heat requirements when brooding tom turkey poults ...

    African Journals Online (AJOL)

    ... 21721, 9476 and 5400 W per week, respectively. When brooding started in the first week of August, poults needed only 5544 W supplementary heat. However, tom turkey poults would nevertheless benefit from supplementary heat during this period because they are not yet fully feathered and the digestive system has not ...

  10. 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

  11. 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

  12. The adaptive significance of inquiline parasite workers

    DEFF Research Database (Denmark)

    Sumner, Seirian; Nash, David R; Boomsma, Jacobus J

    2003-01-01

    Social parasites exploit the socially managed resources of their host's society. Inquiline social parasites are dependent on their host throughout their life cycle, and so many of the traits inherited from their free-living ancestor are removed by natural selection. One trait that is commonly lost...... is the worker caste, the functions of which are adequately fulfilled by host workers. The few inquiline parasites that have retained a worker caste are thought to be at a transitional stage in the evolution of social parasitism, and their worker castes are considered vestigial and non-adaptive. However......, this idea has not been tested. Furthermore, whether inquiline workers have an adaptive role outside the usual worker repertoire of foraging, brood care and colony maintenance has not been examined. In this paper, we present data that suggest that workers of the inquiline ant Acromyrmex insinuator play...

  13. Increased brood size leads to persistent eroded telomeres

    Directory of Open Access Journals (Sweden)

    Sophie eReichert

    2014-04-01

    Full Text Available Costs of reproduction can be divided in mandatory costs coming from physiological, metabolic and anatomical changes required to sustain reproduction itself, and in investment-dependent costs that are likely to become apparent when reproductive efforts are exceeding what organisms were prepared to sustain. Interestingly, recent data showed that entering reproduction enhanced breeders’ telomere loss, but no data explored so far the impact of reproductive investment. Telomeres protect the ends of eukaryote chromosomes. Shortened telomeres were associated with shorter lifespan, telomere erosion being then proposed to powerfully quantify life’s insults. Here, we experimentally manipulated brood size in order to modify reproductive investment of adult zebra finches (Taeniopygia guttata below or beyond their (optimal starting investment and tested the consequences of our treatment on parents’ telomere dynamics. We show that an increased brood size led to a reduction in telomere lengths in both parents compared to control and to parents raising a reduced brood. This greater telomere erosion was detected in parents immediately after the reproductive event and the telomere length difference persisted up to one year later. However, we did not detect any effects of brood size manipulation on annual survival of parents kept under laboratory conditions. In addition, telomere lengths at the end of reproduction were not associated with annual survival. Altogether, although our findings highlight that fast telomere erosion can come as a cost of brood size manipulation, they provide mixed correlative support to the emerging hypothesis that telomere erosion could account for the links between high reproductive investment and longevity.

  14. WHY ARE THERE SO MANY SPECIES OF BROODING ANTARCTIC ECHINOIDS?

    Science.gov (United States)

    Poulin, Élie; Féral, Jean-Pierre

    1996-04-01

    Marine invertebrates display a great variety of life-history traits and reproductive strategies. In echinoids, four patterns of larval development are generally recognized: planktotrophy, pelagic lecithotrophy, bottom dwelling, and brood protecting. Each broad type of free and protected development is found in all the oceans, but comparisons of the principal reproductive modes between different geographic regions have shown that they are not equally distributed. Frequency of pelagic development (planktotrophic and lecithotrophic) decreases from equator to Antarctic, where brood protecting becomes dominant. Numerous theories have been proposed to explain the richness of nonpelagic development in most marine invertebrates within the Southern Ocean. These theories can be grouped into three categories: (1) larval survival, where selection acts on larval; (2) energy allocation; and (3) dispersal. All of them consider the adaptative significance of brood protecting as the key to the success of this strategy in the Antarctic. However, the adaptative significance of brooding and the evolutionary success of this strategy in the Antarctic must be considered as two separate questions. To consider the problem at an evolutionary level, we have examined the consequences of different reproductive strategies on the genetic structure of species and on the long-term evolution of the clade. We examine this problem in the case of echinoids, a clade particularly well suited to addressing this question. In echinoids, the reduction of larval-stage duration is associated with a decrease in gene flow and consequently in the geographical scale of genetic differentiation. This allows us to reconsider the high-speciation-rate model, which leads to an increase in the number of low-dispersal species (isolation by distance). This model, previously tested by means of fossils is not satisfactory in living echinoids. Thus, the model is rebuilt with the addition of differential extinction rate

  15. Workers of a drywood termite do not work.

    Science.gov (United States)

    Korb, Judith

    2007-02-22

    Social insects (ants, bees, wasps and termites) are considered as prime examples of altruism in which individuals (workers) forego their own reproduction to help other individuals reproduce. Such a behaviour is favoured by natural selection because the workers rear close kin and in doing so enhance their inclusive fitness. Here I show, however, that this does not generally apply to termite workers which are scarcely investigated. In the basal drywood termite Cryptotermes secundus the 'workers', which form the large majority of a colony, did not stay to raise relatives. There is no brood caring behaviour and they do not engage in costly help. They are large immature offspring that develop into either winged (dispersing) or unwinged (replacement) reproductives and the probability that they did so was unaffected by the number of brood in the nest as a brood addition experiment showed. Thus, in contrast to general perception where termite workers are considered equivalent to workers in Hymenoptera, the 'large immatures' of C. secundus did not behave as workers that help in raising younger siblings. This apparently is not necessary as the colony lives inside its food. These results, which are likely to be typical for wood-dwelling termites, open the possibility that large complex group living can evolve without altruistic helping and that costly altruistic helping by workers in termites evolved only as a second step.

  16. Workers of a drywood termite do not work

    Directory of Open Access Journals (Sweden)

    Korb Judith

    2007-02-01

    Full Text Available Abstract Background Social insects (ants, bees, wasps and termites are considered as prime examples of altruism in which individuals (workers forego their own reproduction to help other individuals reproduce. Such a behaviour is favoured by natural selection because the workers rear close kin and in doing so enhance their inclusive fitness. Results Here I show, however, that this does not generally apply to termite workers which are scarcely investigated. In the basal drywood termite Cryptotermes secundus the 'workers', which form the large majority of a colony, did not stay to raise relatives. There is no brood caring behaviour and they do not engage in costly help. They are large immature offspring that develop into either winged (dispersing or unwinged (replacement reproductives and the probability that they did so was unaffected by the number of brood in the nest as a brood addition experiment showed. Conclusion Thus, in contrast to general perception where termite workers are considered equivalent to workers in Hymenoptera, the 'large immatures' of C. secundus did not behave as workers that help in raising younger siblings. This apparently is not necessary as the colony lives inside its food. These results, which are likely to be typical for wood-dwelling termites, open the possibility that large complex group living can evolve without altruistic helping and that costly altruistic helping by workers in termites evolved only as a second step.

  17. Contamination rates between smart cell phones and non-smart cell phones of healthcare workers.

    Science.gov (United States)

    Lee, Yeon Joo; Yoo, Chul-Gyu; Lee, Choon-Taek; Chung, Hee Soon; Kim, Young Whan; Han, Sung Koo; Yim, Jae-Joon

    2013-03-01

    Healthcare workers' mobile phones are easily contaminated with pathogenic bacteria and could be vehicles of transmission. Smart phones are increasingly used in the hospital. The objective of this study was to compare the contamination rate of bacteria with pathogenic potential between smart phones and non-smart phones. We screened mobile phones of healthcare workers in three teaching hospitals in South Korea. The identification of cultivated micro-organisms and assessment of antibiotic susceptibility were performed. One hundred fifteen (56.7%) participants used smart phones, and 88 (43.3%) used non-smart phones. Bacteria with pathogenic potential were isolated from 58 (28.6%) mobile phones, more often from smart phones than from non-smart phones (34.8% vs 20.5%, P=0.03). Multivariate analysis including various characteristics to determine risk factors revealed that only smart phones (vs non-smart phones) were a significant risk factor for contamination by bacteria with pathogenic potential (adjusted odds ratio [OR], 4.02; 95% confidence interval [CI], 1.43-11.31). Also, in a multivariate model including phone size, the smart phone was still a significant risk factor for the pathogen contamination (OR, 4.17; 95% CI, 1.07-16.33; P=0.04). The smart phones of healthcare workers were contaminated with bacteria with pathogenic potential to a greater extent than were non-smart phones. Copyright © 2013 Society of Hospital Medicine.

  18. Parental investment with a superior alien in the brood.

    Science.gov (United States)

    Holen, Ø H; Johnstone, R A

    2007-11-01

    When a parent's parentage differs across breeding attempts, established theory predicts that the parent should invest more in a brood when perceived parentage is high. We present a model of parental investment in which offspring unrelated to the parent have a competitive advantage over the parent's own offspring and take a larger share of investment. We show that this can weaken or, if the competitive advantage is great, reverse the predicted relationship between perceived parentage and parental investment. A moderate competitive advantage of extra-pair young over within-pair young could partly explain the lack of any clear relationship between paternal care and paternity in many studies, and could easily arise if females choose extra-pair partners for good genes. Our results are also relevant to interspecific avian brood parasitism. As parasites reared together with host offspring are often superior competitors, their hosts could benefit from increasing investment in response to suspected parasitism.

  19. Evaluating smallholder brood- and- sale poultry operation using ...

    African Journals Online (AJOL)

    A total of 92 crossbred pullet chicks of normal feather (44), naked neck (27) and frizzle (21) were used to evaluate early growth performance and monetary returns of a simulated smallholder brood-and-sale poultry production operation. Average day-old (D.O.) weight of chicks were 34.57±0.98g, 35.28±0.59g and ...

  20. Adoption levels and information sources of "brood and sell" poultry ...

    African Journals Online (AJOL)

    Adoption levels and information sources of "brood and sell" poultry operators. MO Onu, MC Madukwe. Abstract. No Abstract. Agro-Science Vol. 3(1) 2002: 63-67. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · http://dx.doi.org/10.4314/as.v3i1.1505 · AJOL African ...

  1. Honeybee Colony Vibrational Measurements to Highlight the Brood Cycle.

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

  3. Glycophorin A somatic cell mutation frequencies in Finnish reinforced plastics workers exposed to styrene.

    Science.gov (United States)

    Bigbee, W L; Grant, S G; Langlois, R G; Jensen, R H; Anttila, A; Pfäffli, P; Pekari, K; Norppa, H

    1996-10-01

    We have used the glycophorin A (GPA) in vivo somatic cell mutation assay to assess the genotoxic potential of styrene exposure in 47 reinforced plastics workers occupationally exposed to styrene and 47 unexposed controls matched for age, gender, and active smoking status. GPA variant erythrocyte frequencies (Vf), reflecting GPA allele loss (phi/N) and allele loss and duplication (N/N) somatic mutations arising in vivo in the erythroid progenitor cells of individuals of GPA M/N heterozygous genotype, were flow cytometrically determined in peripheral blood samples from these subjects. Measurements of styrene exposure of the workers at the time of blood sampling showed a mean 8-h time-weighted average (TWA8-h) styrene concentration of 155 mg/m3 (37 ppm) in the breathing zone. Mean urinary concentrations of the styrene metabolites mandelic acid (MA) and mandelic acid plus phenyl glyoxylic acid (MA+PGA) were 4.4 mmol/liter (after workshift) and 2.1 mmol/liter (next morning), respectively. Multivariate analysis of covariance on log-transformed GPA Vf data with models allowing adjustment for age, gender, smoking status, and styrene exposure showed that N/N Vf were nearly significantly increased among all of the exposed workers (adjusted geometric mean, 6.3 per million versus 5.0 in the controls; P = 0.058) and were statistically significantly elevated (adjusted geometric mean, 6.8 versus 5.0 in the controls; P = 0.036) among workers classified into a high-exposure group according to personal TWA8-h concentration of styrene in the breathing zone of > or = 85 mg/m3 (20 ppm; Finnish threshold limit value). Women in this high exposure group showed especially elevated N/N Vf (adjusted geometric mean 8.5 versus 5.3 in control women; P = 0.020); this elevation was also significant if urinary MA+PGA of > or = 1.2 mmol/liter was used as the basis of classification (adjusted geometric mean, 8.3; P = 0.030). The occupational exposure could not be shown to influence phi/N Vf

  4. 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

  5. Susceptibility of Bee Larvae to Chalkbrood in Relation to Hygienic Behaviour of Worker Bees in Colonies of Chosen Races of Honeybee (Apis Mellifera

    Directory of Open Access Journals (Sweden)

    Panasiuk Beata

    2014-06-01

    Full Text Available The susceptibility of bee larvae to Ascosphaera apis infestation and the hygienic behaviour of worker bees in relation to A. apis infected and freeze-killed brood were evaluated in three races of bees: Apis mellifera carnica, Apis mellifera caucasica, and Apis mellifera mellifera. Experimental bee colonies were evaluated in field conditions during the three beekeeping seasons. The lowest percentage of infected larvae was observed in car GR1 and mel A colonies (8.5% and 15%, respectively and the highest in car Mr and cau P colonies (21% and 24.3%, respectively. Bees in the car GR1 and mel A colonies removed mummified brood in a shorter period of time (6.5 and 7.1 days on average, respectively than car Mr and cau P colonies (above 8 days. Bees in the mel A and car GR1 colonies cleaned significantly more cells with freeze-killed brood within 24 and 48 hours (above 70% and 80% on average, respectively than car Mr and cau P colonies (on average 10 - 20% lower cleaning rate. A low correlation coefficient was found for the susceptibility of larvae to A. apis infection and hygienic behaviour.

  6. 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)

  7. 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

    Brood desertion involves a series of interactions between the members of a pair. This process is likely to be based on either member's perception of the other's propensity to desert. We manipulated this perception in males by experimentally increasing female body mass in the rock sparrow (Petronia...... 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...... 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...

  8. Effect of Varroa destructor, Wounding and Varroa Homogenate on Gene Expression in Brood and Adult Honey Bees.

    Science.gov (United States)

    Koleoglu, Gun; Goodwin, Paul H; Reyes-Quintana, Mariana; Hamiduzzaman, Mollah Md; Guzman-Novoa, Ernesto

    2017-01-01

    Honey bee (Apis mellifera) gene expression related to immunity for hymenoptaecin (AmHym) and defensin-1 (AmDef-1), longevity for vitellogenin (AmVit2) and stem cell proliferation for poly U binding factor 68 kDa (AmPuf68) was compared following Varroa destructor parasitism, buffer injection and injection of V. destructor compounds in its homogenate. In adults, V. destructor parasitism decreased expression of all four genes, while buffer injection decreased expression of AmHym, AmPuf68 and AmVit2, and homogenate injection decreased expression of AmPuf68 and AmVit2 but increased expression of AmDef-1 relative to their respective controls. The effect of V. destructor parasitism in adults relative to the controls was not significantly different from buffer injection for AmHym and AmVit2 expression, and it was not significantly different from homogenate injection for AmPuf68 and AmVit2. In brood, V. destructor parasitism, buffer injection and homogenate injection decreased AmVit2 expression, whereas AmHym expression was decreased by V. destructor parasitism but increased by buffer and homogenate injection relative to the controls. The effect of varroa parasitism in brood was not significantly different from buffer or homogenate injection for AmPuf68 and AmVit2. Expression levels of the four genes did not correlate with detectable viral levels in either brood or adults. The results of this study indicate that the relative effects of V. destructor parasitism on honey bee gene expression are also shared with other types of stresses. Therefore, some of the effects of V. destructor on honey bees may be mostly due to wounding and injection of foreign compounds into the hemolymph of the bee during parasitism. Although both brood and adults are naturally parasitized by V. destructor, their gene expression responded differently, probably the result of different mechanisms of host responses during development.

  9. Habitat selection and movements of Piping Plover broods suggest a tradeoff between breeding stages

    Science.gov (United States)

    Wiltermuth, Mark T.; Anteau, Michael J.; Sherfy, Mark H.; Pearse, Aaron T.

    2015-01-01

    In precocial birds, adults select breeding areas using cues associated with habitat characteristics that are favorable for nesting success and chick survival, but there may be tradeoffs in habitat selection between these breeding stages. Here we describe habitat selection and intra-territory movements of 53 Piping Plover (Charadrius melodus) broods (320 observations) during the 2007–2008 breeding seasons on mainland- and island-shoreline habitats at Lake Sakakawea, North Dakota, USA. We used remotely sensed habitat characteristics to separately examine habitat selection and movements at two spatiotemporal scales to account for potential confounding effects of nest-site selection on brood-rearing habitat used. The scales used were (1) the entire brood-rearing period within available brood-rearing areas and (2) 2-day observation intervals within age-specific discrete habitat selection choice sets. Analyses at both scales indicated that broods selected areas which were non-vegetated, moderately level, and nearer to the shoreline. Rate of brood movement increased with age up to 5 days, then stabilized; broods that hatched >50 m away from the shoreline moved toward the shoreline. Brood movements were greater when they were in vegetated areas, when the brood-rearing area was of greater topographic complexity, and when broods aged 6–25 days were further away from the shoreline. Using inferences from our results and those of previously published work, we postulate how a potential tradeoff in habitat selection between nesting and brood-rearing can contribute to an ecological trap in a novel habitat. This work, in the context of published works, suggests that plover breeding habitat is a complex of both nesting and brood-rearing habitats and provides a basis for making remotely sensed abundance estimates of suitable breeding habitat for Piping Plovers.

  10. Diet and cell size both affect queen-worker differentiation through DNA methylation in honey bees (Apis mellifera, Apidae.

    Directory of Open Access Journals (Sweden)

    Yuan Yuan Shi

    Full Text Available BACKGROUND: Young larvae of the honey bee (Apis mellifera are totipotent; they can become either queens (reproductives or workers (largely sterile helpers. DNA methylation has been shown to play an important role in this differentiation. In this study, we examine the contributions of diet and cell size to caste differentiation. METHODOLOGY/PRINCIPAL FINDINGS: We measured the activity and gene expression of one key enzyme involved in methylation, Dnmt3; the rates of methylation in the gene dynactin p62; as well as morphological characteristics of adult bees developed either from larvae fed with worker jelly or royal jelly; and larvae raised in either queen or worker cells. We show that both diet type and cell size contributed to the queen-worker differentiation, and that the two factors affected different methylation sites inside the same gene dynactin p62. CONCLUSIONS/SIGNIFICANCE: We confirm previous findings that Dnmt3 plays a critical role in honey bee caste differentiation. Further, we show for the first time that cell size also plays a role in influencing larval development when diet is kept the same.

  11. Diet and cell size both affect queen-worker differentiation through DNA methylation in honey bees (Apis mellifera, Apidae).

    Science.gov (United States)

    Shi, Yuan Yuan; Huang, Zachary Y; Zeng, Zhi Jiang; Wang, Zi Long; Wu, Xiao Bo; Yan, Wei Yu

    2011-04-26

    Young larvae of the honey bee (Apis mellifera) are totipotent; they can become either queens (reproductives) or workers (largely sterile helpers). DNA methylation has been shown to play an important role in this differentiation. In this study, we examine the contributions of diet and cell size to caste differentiation. We measured the activity and gene expression of one key enzyme involved in methylation, Dnmt3; the rates of methylation in the gene dynactin p62; as well as morphological characteristics of adult bees developed either from larvae fed with worker jelly or royal jelly; and larvae raised in either queen or worker cells. We show that both diet type and cell size contributed to the queen-worker differentiation, and that the two factors affected different methylation sites inside the same gene dynactin p62. We confirm previous findings that Dnmt3 plays a critical role in honey bee caste differentiation. Further, we show for the first time that cell size also plays a role in influencing larval development when diet is kept the same.

  12. 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.

  13. Beneficial insect borders provide northern bobwhite brood habitat.

    Directory of Open Access Journals (Sweden)

    Christopher E Moorman

    Full Text Available 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.

  14. Brood removal influences fall of Varroa destructor (Mesostigmata: Varroidae) in honey bee (Hymenoptera: Apidae) colonies

    Science.gov (United States)

    The hygienic removal of brood infested with Varroa destructor by Apis mellifera disrupts the reproduction of the infesting mites and exposes the foundress mites to potential removal from the colony by grooming. Using brood deliberately infested with marked Varroa, we investigated the association bet...

  15. 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...

  16. Aggressive behavior of the male parent predicts brood sex ratio in a songbird

    Science.gov (United States)

    Szász, Eszter; Garamszegi, László Zsolt; Hegyi, Gergely; Szöllősi, Eszter; Markó, Gábor; Török, János; Rosivall, Balázs

    2014-08-01

    Brood sex ratio is often affected by parental or environmental quality, presumably in an adaptive manner that is the sex that confers higher fitness benefits to the mother is overproduced. So far, studies on the role of parental quality have focused on parental morphology and attractiveness. However, another aspect, the partner's behavioral characteristics, may also be expected to play a role in brood sex ratio adjustment. To test this hypothesis, we investigated whether the proportion of sons in the brood is predicted by the level of territorial aggression displayed by the father, in the collared flycatcher ( Ficedula albicollis). The proportion of sons in the brood was higher in early broods and increased with paternal tarsus length. When controlling for breeding date and body size, we found a higher proportion of sons in the brood of less aggressive fathers. Male nestlings are more sensitive to the rearing environment, and the behavior of courting males may often be used by females to assess their future parental activity. Therefore, adjusting brood sex ratio to the level of male aggression could be adaptive. Our results indicate that the behavior of the partner could indeed be a significant determinant in brood sex ratio adjustment, which should not be overlooked in future studies.

  17. Brooding in a temperate zone land snail: seasonal and regional patterns

    NARCIS (Netherlands)

    Sulikowska-Drozd, A.; Maltz, T.K.; Kappes, H.

    2013-01-01

    The goal of this study is to assess if the reproductive strategy of a brooding land snail shifts along a climatic gradient. We focused on the following traits: timing and length of the reproductive season, brood size, ontogenetic dynamics of embryos, and reproductive mode (viviparity versus

  18. 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…

  19. Effects of brood size manipulations on sexual attractiveness of offspring in the zebra finch

    NARCIS (Netherlands)

    DeKogel, CH; Prijs, HJ

    In a laboratory study the effect of brood size manipulations on the sexual attractiveness of offspring was investigated. Zebra finches, Taeniopygia guttata, were reared in small or large broods. Young were exchanged so that natural siblings from different rearing conditions could be compared. Birds

  20. 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.

  1. Effects of cross-feeding anarchistic and wild type honey bees: anarchistic workers are not queen-like.

    Science.gov (United States)

    Beekman, Madeleine; Oldroyd, Benjamin P

    2003-04-01

    Unlike normal (wild type) honey bee ( Apis mellifera) colonies, 'anarchistic' colonies are characterised by workers that activate their ovaries in the presence of the queen and brood and by the ability of their workers to lay eggs that evade worker policing. In the Cape honey bee ( A. m. capensis), female larvae can manipulate non- capensis nurse workers such that they receive more larval food and develop into worker-queen intermediates or intercastes. We speculated that, in anarchistic colonies, larvae might produce signals that result in excessive feeding of female larvae. Excessively fed female larvae may then develop into reproductively active workers. In this study we cross-fostered anarchistic and wild type brood and investigated the effect of cross-fostering on the amount of food fed to larvae and on the morphology of the resulting workers. We show that anarchistic larvae do not manipulate wild type nurse workers into feeding them more, nor do anarchistic workers develop into worker-queen intermediates. On the contrary, anarchistic larvae are fed less than wild type larvae and anarchistic workers seem to be poor nurses in that they feed larvae less, irrespective of brood genotype.

  2. Fecundity and trapping of Varroa destructor (Mesostigmata: Varroidae in Greek drone brood of Apis melifera (Hymenoptera: Apididae

    Directory of Open Access Journals (Sweden)

    Petros T. Damos

    2012-12-01

    Full Text Available This study estimates the parasitization levels and fecundity of the ectoparasitic mite Varroa destructor Oudemans in drone brood of bee colonies located in Northern Greece. Based on successive observations in spring and early summer, the study also examines whether early entrapment of mites into the drone brood cell decreases the mite population levels in the succeeding generation. Varroa populations in drone brood were extremely high (approx. 40% in early spring, although numbers dropped significantly (approx. 20% after the entrapment and removal of mites into the drone brood (t=4.14518, P=0.0136, Mann-Whitney: P=0.005. In most cases, more than half of the inspected cells were occupied with two or more parental mites. No significant differences were found in the reproductive performance of the Varroa mites between the two successive generations in spring and early summer (t=-0.607, P=0.554, Mann-Whitney: P=0.128. The reproductive performance of V. destructor ranged from 1.5-3 progeny per female individual (m1:1.673, SE=0.09 and m2:2.02, SE: 0.44 for the first and second generations, respectively. A positive and significant correlation was observed between the drone and the mite populations (y=0.830+1.153x, F=8.851, P=0.41, R2:0.689 and y=0.319+0.968x, F=45.276, R2: 0,938, P=0.07 for the first and second mite generations, respectively. There were no significant differences in the number of infested and non-infested cells during the first observations (m1: 105.2, SE: 25.0, m2: 170.0 SE: 40.0, t=-1.38, P=0.203, Mann-Whitney: n1:81.0, n2:142.5, P=0.0656. On the contrary, during the second observations the number of infested cells was significantly lower (m1: 27.6, SE:8.1, m2:262.8, SE:69.0, t=-3.39, P=0.027, Mann-Whitney: P=0.012, n1:20, n2:340.

  3. Diet and Cell Size Both Affect Queen-Worker Differentiation through DNA Methylation in Honey Bees (Apis mellifera, Apidae)

    OpenAIRE

    Shi, Yuan Yuan; Huang, Zachary Y.; Zeng, Zhi Jiang; Wang, Zi Long; Wu, Xiao Bo; Yan, Wei Yu

    2011-01-01

    BACKGROUND: Young larvae of the honey bee (Apis mellifera) are totipotent; they can become either queens (reproductives) or workers (largely sterile helpers). DNA methylation has been shown to play an important role in this differentiation. In this study, we examine the contributions of diet and cell size to caste differentiation. METHODOLOGY/PRINCIPAL FINDINGS: We measured the activity and gene expression of one key enzyme involved in methylation, Dnmt3; the rates of methylation in the gene ...

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

    Science.gov (United States)

    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.

  5. Expression of acetylcholinesterase 1 is associated with brood rearing status in the honey bee, Apis mellifera.

    Science.gov (United States)

    Kim, Young Ho; Kim, Ju Hyeon; Kim, Kyungmun; Lee, Si Hyeock

    2017-01-03

    Acetylcholinesterase 1 (AmAChE1) of the honey bee, Apis mellifera, has been suggested to have non-neuronal functions. A systematic expression profiling of AmAChE1 over a year-long cycle on a monthly basis revealed that AmAChE1 was predominantly expressed in both head and abdomen during the winter months and was moderately expressed during the rainy summer months. Interestingly, AmAChE1 expression was inhibited when bees were stimulated for brood rearing by placing overwintering beehives in strawberry greenhouses with a pollen diet, whereas it resumed when the beehives were moved back to the cold field, thereby suppressing brood rearing. In early spring, pollen diet supplementation accelerated the induction of brood-rearing activity and the inhibition of AmAChE1 expression. When active beehives were placed in a screen tent in late spring, thereby artificially suppressing brood-rearing activity, AmAChE1 was highly expressed. In contrast, AmAChE1 expression was inhibited when beehives were allowed to restore brood rearing by removing the screen, supporting the hypothesis that brood rearing status is a main factor in the regulation of AmAChE1 expression. Since brood rearing status is influenced by various stress factors, including temperature and diet shortage, our finding discreetly suggests that AmAChE1 is likely involved in the stress response or stress management.

  6. How is anxiety involved in the longitudinal relationship between brooding rumination and depressive symptoms in adolescents?

    Science.gov (United States)

    Jose, Paul E; Weir, Kirsty F

    2013-08-01

    A growing body of research supports the application of Response Styles Theory to adolescent populations. Although the essential dynamic, namely that rumination increases the incidence of depressive symptoms, has been demonstrated among adolescents, a number of important empirical questions remain, such as: what are the gender differences and developmental trends for brooding and reflective rumination?; does a reciprocal relationship exist between brooding or reflective rumination, on the one hand, and depressive symptoms and anxiety, on the other hand, over time? and how do additional variables (i.e., anxiety) impact upon the rumination-depressive symptoms relationship? In this study, self-reported levels of rumination (both brooding and reflective), and anxious and depressive symptoms were measured longitudinally across 4 months in a sample of 976 community adolescents (46% females), aged 11-16 years old. Mean group differences showed that female adolescents reported engaging in more brooding rumination than male adolescents beginning at 13 years of age. A reciprocal brooding rumination to depressive symptoms relationship and a reciprocal brooding rumination to anxiety relationship were found over time, and they did not differ for boys and girls. We tested the possibility that anxious symptoms would function as a third variable, but the obtained model showed that brooding rumination and anxiety both contributed unique variance in predicting changes in depressive symptoms over time.

  7. 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.

  8. Increased micronucleus frequencies in surrogate and target cells from workers exposed to crystalline silica-containing dust.

    Science.gov (United States)

    Demircigil, Gonca Cakmak; Coskun, Erdem; Vidinli, Nuri; Erbay, Yildiray; Yilmaz, Metin; Cimrin, Arif; Schins, Roel P; Borm, Paul J; Burgaz, Sema

    2010-03-01

    Mining, crushing, grinding, sandblasting and construction are high-risk activities with regard to crystalline silica exposure, especially in developing countries. Respirable crystalline silica (quartz and cristobalite) inhaled from occupational sources has been reclassified as a human carcinogen in 1997 by the International Agency for Research on Cancer. However, the biological activity of crystalline silica has been found to be variable among different industries, and this has formed the basis for further in vivo/in vitro mechanistic research and epidemiologic studies. This study was conducted for genotoxicity evaluation in a population of workers (e.g. glass industry workers, sandblasters, and stone grinders) mainly exposed to crystalline silica in four different workplaces in Turkey. The micronucleus (MN) assay was applied both in peripheral blood lymphocytes (PBL) as a surrogate tissue and in nasal epithelial cells (NEC) as a target tissue of the respiratory tract. Our study revealed significantly higher MN frequencies in the workers (n = 50) versus the control group (n = 29) (P crystalline silica levels exceeding limit values and mineralogical/elemental dust composition of the dust of at least 70% SiO(2) were used as markers of crystalline silica exposure in each of the workplaces. Moreover, 24% of the current workers were found to have early radiographical changes (profusion category of 1). In conclusion, although the PBL are not primary target cells for respiratory particulate toxicants, an evident increase in MN frequencies in this surrogate tissue was observed, alongside with a significant increase in NEC and may be an indicator of the accumulated genetic damage associated with crystalline silica exposure.

  9. Establishment of Characteristic Gut Bacteria during Development of the Honeybee Worker

    Science.gov (United States)

    Moy, Jamie

    2012-01-01

    Previous surveys have shown that adult honeybee (Apis mellifera) workers harbor a characteristic gut microbiota that may play a significant role in bee health. For three major phylotypes within this microbiota, we have characterized distributions and abundances across the life cycle and among gut organs. These distinctive phylotypes, called Beta, Firm-5, and Gamma-1 (BFG), were assayed using quantitative PCR, fluorescent in situ hybridization (FISH) microscopy, and the experimental manipulation of inoculation routes within developing bees. Adult workers (9 to 30 days posteclosion) contained a large BFG microbiota with a characteristic distribution among gut organs. The crop and midgut were nearly devoid of these phylotypes, while the ileum and rectum together contained more than 95% of the total BFG microbiota. The ileum contained a stratified community in which the Beta and Gamma-1 phylotypes dominated, filling the longitudinal folds of this organ. Deep sequencing of 16S rRNA genes showed clear differences among communities in midgut, ileum, and rectum. In contrast with older workers, larvae and newly emerged workers contain few or no bacteria, and their major food source, bee bread, lacks most characteristic phylotypes. In experiments aimed at determining the route of inoculation, newly emerged workers (NEWs) sometimes acquired the typical phylotypes through contact with older workers, contact with the hive, and emergence from the brood cell; however, transmission was patchy in these assays. Our results outline a colonization pattern for the characteristic phylotypes through A. mellifera ontogeny. We propose the names “Candidatus Snodgrassella alvi” and “Candidatus Gilliamella apicola” for the Beta and Gamma-1 phylotypes, respectively. PMID:22307297

  10. 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)

  11. Effect of Varroa destructor, Wounding and Varroa Homogenate on Gene Expression in Brood and Adult Honey Bees.

    Directory of Open Access Journals (Sweden)

    Gun Koleoglu

    Full Text Available Honey bee (Apis mellifera gene expression related to immunity for hymenoptaecin (AmHym and defensin-1 (AmDef-1, longevity for vitellogenin (AmVit2 and stem cell proliferation for poly U binding factor 68 kDa (AmPuf68 was compared following Varroa destructor parasitism, buffer injection and injection of V. destructor compounds in its homogenate. In adults, V. destructor parasitism decreased expression of all four genes, while buffer injection decreased expression of AmHym, AmPuf68 and AmVit2, and homogenate injection decreased expression of AmPuf68 and AmVit2 but increased expression of AmDef-1 relative to their respective controls. The effect of V. destructor parasitism in adults relative to the controls was not significantly different from buffer injection for AmHym and AmVit2 expression, and it was not significantly different from homogenate injection for AmPuf68 and AmVit2. In brood, V. destructor parasitism, buffer injection and homogenate injection decreased AmVit2 expression, whereas AmHym expression was decreased by V. destructor parasitism but increased by buffer and homogenate injection relative to the controls. The effect of varroa parasitism in brood was not significantly different from buffer or homogenate injection for AmPuf68 and AmVit2. Expression levels of the four genes did not correlate with detectable viral levels in either brood or adults. The results of this study indicate that the relative effects of V. destructor parasitism on honey bee gene expression are also shared with other types of stresses. Therefore, some of the effects of V. destructor on honey bees may be mostly due to wounding and injection of foreign compounds into the hemolymph of the bee during parasitism. Although both brood and adults are naturally parasitized by V. destructor, their gene expression responded differently, probably the result of different mechanisms of host responses during development.

  12. 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

    Fungus-growing ants (Myrmicinae: Attini) live in an obligate symbiotic relationship with a fungus that they rear for food, but they can also use the fungal mycelium to cover their brood. We surveyed colonies from 20 species of fungus-growing ants and show that brood-covering behavior occurs in most...... 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...

  13. 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.

  14. Sickle cell knowledge, premarital screening and marital decisions among local government workers in Ile-Ife, Nigeria

    OpenAIRE

    Abioye-Kuteyi, Emmanuel A; Olanrewaju Oyegbade; Ibrahim Bello; Chiddude Osakwe

    2009-01-01

    Background: In Nigeria, as in the rest of equatorial Africa, sickle cell disease (SCD) has its highest incidence and continues to cause high morbidity and early death. The condition is a major public health problem among the black race. The aim of this survey is to determine the level of knowledge about SCD and the factors associated with its prevention among local government workers in Ile- Ife.Method: This is a cross-sectional descriptive study of the knowledge about SCD, attitude towards p...

  15. Idiopathic brood disease syndrome and queen events as precursors of colony mortality in migratory beekeeping operations in the eastern United States.

    Science.gov (United States)

    vanEngelsdorp, Dennis; Tarpy, David R; Lengerich, Eugene J; Pettis, Jeffery S

    2013-02-01

    Using standard epidemiological methods, this study set out to quantify the risk associated with exposure to easily diagnosed factors on colony mortality and morbidity in three migratory beekeeping operations. Fifty-six percent of all colonies monitored during the 10-month period died. The relative risk (RR) that a colony would die over the short term (∼50 days) was appreciably increased in colonies diagnosed with Idiopathic Brood Disease Syndrome (IBDS), a condition where brood of different ages appear molten on the bottom of cells (RR=3.2), or with a "queen event" (e.g., evidence of queen replacement or failure; RR=3.1). We also found that several risk factors-including the incidence of a poor brood pattern, chalkbood (CB), deformed wing virus (DWV), sacbrood virus (SBV), and exceeding the threshold of 5 Varroa mites per 100 bees-were differentially expressed in different beekeeping operations. Further, we found that a diagnosis of several factors were significantly more or less likely to be associated with a simultaneous diagnosis of another risk factor. These finding support the growing consensus that the causes of colony mortality are multiple and interrelated. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. Effects of experimental brood size manipulation and gender on carotenoid levels of Eurasian kestrels Falco tinnunculus.

    Directory of Open Access Journals (Sweden)

    Toni Laaksonen

    Full Text Available BACKGROUND: Animals use carotenoid-pigments for coloration, as antioxidants and as enhancers of the immune system. Carotenoid-dependent colours can thus signal individual quality and carotenoids have also been suggested to mediate life-history trade-offs. METHODOLOGY: To examine trade-offs in carotenoid allocation between parents and the young, or between skin coloration and plasma of the parents at different levels of brood demand, we manipulated brood sizes of Eurasian kestrels (Falco tinnunculus. PRINCIPAL FINDINGS: Brood size manipulation had no overall effect on plasma carotenoid levels or skin hue of parents, but female parents had twice the plasma carotenoid levels of males. Males work physically harder than females and they might thus also use more carotenoids against oxidative stress than females. Alternatively, females could be gaining back the carotenoid stores they depleted during egg-laying by eating primarily carotenoid-rich food items during the early nestling stage. Fledglings in enlarged broods had higher plasma carotenoid concentrations than those in reduced broods. This difference was not explained by diet. In light of recent evidence from other species, we suggest it might instead be due to fledglings in enlarged broods having higher testosterone levels, which in turn increased plasma carotenoid levels. The partial cross-foster design of our experiment revealed evidence for origin effects (genetic or maternal on carotenoid levels of fledglings, but no origin-environment interaction. SIGNIFICANCE: These results from wild birds differ from studies in captivity, and thus offer new insights into carotenoid physiology in relation to division of parental care and demands of the brood.

  17. An externally brooding acorn worm (Hemichordata, Enteropneusta, Torquaratoridae) from the Russian arctic.

    Science.gov (United States)

    Osborn, Karen J; Gebruk, Andrey V; Rogacheva, Antonina; Holland, Nicholas D

    2013-10-01

    A single specimen of a previously undescribed acorn worm in the family Torquaratoridae was trawled from a bottom depth of about 350 m in the Kara Sea (Russian Arctic). The new species is the shallowest of the exclusively deep-sea torquaratorids found to date, possibly an example of high-latitude emergence. On the basis of ribosomal DNA sequences and morphology, the worm is described here as the holotype of Coleodesmium karaensis n. gen., n. sp. It is most similar in overall body shape to the previously described enteropneust genus Allapasus, but is uniquely characterized by a tubular component of the proboscis skeleton ensheathing the collar nerve cord. Additionally, within the proboscis, the sparseness of the musculature of C. karaensis clearly distinguishes it from the much more muscular members of Allapasus. The holotype is a female bearing about a dozen embryos on the surface of her pharyngeal region, each recessed within a shallow depression in the dorsal epidermis. The embryos, ranging from late gastrula to an early stage of coelom formation, are a little more than 1 mm in diameter and surrounded by a thin membrane. Each embryo comprises an external ectoderm of monociliated cells (not arranged in obvious ciliated bands) and an internal endo-mesoderm; the blastopore is closed. In the most advanced embryos, the anterior coelom is starting to constrict off from the archenteron. Coleodesmium karaensis is the first enteropneust (and indeed the first hemichordate) found brooding embryos on the surface of the mother's body.

  18. Reproductive conflict in social insects: male production by workers in a slave-making ant.

    Science.gov (United States)

    Brunner, Elisabeth; Trindl, Andreas; Falk, Karl H; Heinze, Juergen; D'Ettorre, Patrizia

    2005-11-01

    In insect societies, workers cooperate but may also pursue their individual interests, such as laying viable male eggs. The case of obligatory slave-making ants is of particular interest because workers do not engage in maintenance activities and foraging. Therefore, worker egg laying is expected to be less detrimental for colony efficiency than in related, nonparasitic species. Furthermore, as slave-making workers usually do not perform brood care and thus might have little power in manipulating sex allocation, they might be more strongly selected to increase their direct fitness by producing their own sons than workers in nonparasitic species. In this study we investigated worker reproduction in four natural colonies of the slave-making ant Polyergus rufescens, using highly variable microsatellite markers. Our results show that workers produce up to 100% of the males. This study thus presents the first direct evidence of an almost complete takeover of male reproduction by workers in ants.

  19. Three-dimensional visualisation of brooding behaviour in two distantly related brittle stars from South African waters

    National Research Council Canada - National Science Library

    Landschoff, J; Griffiths, CL

    2015-01-01

    .... In South African waters, brooding occurs both in the very small amphiurid Amphipholis squamata, which is hermaphroditic, and in the large ophiodermatid Ophioderma wahlbergii, which is gonochoric...

  20. Species richness and distributions of boreal waterbirds in relation to nesting and brood-rearing habitats

    Science.gov (United States)

    Lewis, Tyler L.; Lindberg, Mark S.; Schmutz, Joel A.; Bertram, Mark R.; Dubour, Adam J.

    2015-01-01

    Identification of ecological factors that drive animal distributions allows us to understand why distributions vary temporally and spatially, and to develop models to predict future changes to populations–vital tools for effective wildlife management and conservation. For waterbird broods in the boreal forest, distributions are likely driven by factors affecting quality of nesting and brood-rearing habitats, and the influence of these factors may extend beyond singles species, affecting the entire waterbird community. We used occupancy models to assess factors influencing species richness of waterbird broods on 72 boreal lakes, along with brood distributions of 3 species of conservation concern: lesser scaup (Aythya affinis), white-winged scoters (Melanitta fusca), and horned grebe (Podiceps auritus). Factors examined included abundance of invertebrate foods (Amphipoda, Diptera, Gastropoda, Hemiptera, Odonata), physical lake attributes (lake area, emergent vegetation), water chemistry (nitrogen, phosphorus, chlorophyll a concentrations), and nesting habitats (water edge, non-forest cover). Of the 5 invertebrates, only amphipod density was related to richness and occupancy, consistently having a large and positive relationship. Despite this importance to waterbirds, amphipods were the most patchily distributed invertebrate, with 17% of the study lakes containing 70% of collected amphipods. Lake area was the only other covariate that strongly and positively influenced species richness and occupancy of scaup, scoters, and grebes. All 3 water chemistry covariates, which provided alternative measures of lake productivity, were positively related to species richness but had little effect on scaup, scoter, and grebe occupancy. Conversely, emergent vegetation was negatively related to richness, reflecting avoidance of overgrown lakes by broods. Finally, nesting habitats had no influence on richness and occupancy, indicating that, at a broad spatial scale, brood

  1. Coevolution is linked with phenotypic diversification but not speciation in avian brood parasites

    Science.gov (United States)

    Medina, Iliana; Langmore, Naomi E.

    2015-01-01

    Coevolution is often invoked as an engine of biological diversity. Avian brood parasites and their hosts provide one of the best-known examples of coevolution. Brood parasites lay their eggs in the nests of other species, selecting for host defences and reciprocal counteradaptations in parasites. In theory, this arms race should promote increased rates of speciation and phenotypic evolution. Here, we use recently developed methods to test whether the three largest avian brood parasitic lineages show changes in rates of phenotypic diversity and speciation relative to non-parasitic lineages. Our results challenge the accepted paradigm, and show that there is little consistent evidence that lineages of brood parasites have higher speciation or extinction rates than non-parasitic species. However, we provide the first evidence that the evolution of brood parasitic behaviour may affect rates of evolution in morphological traits associated with parasitism. Specifically, egg size and the colour and pattern of plumage have evolved up to nine times faster in parasitic than in non-parasitic cuckoos. Moreover, cuckoo clades of parasitic species that are sympatric (and share similar host genera) exhibit higher rates of phenotypic evolution. This supports the idea that competition for hosts may be linked to the high phenotypic diversity found in parasitic cuckoos. PMID:26702044

  2. If I only knew why: the relationship between brooding, beliefs about rumination, and perceptions of treatments.

    Science.gov (United States)

    Ophir, Yaakov; Mor, Nilly

    2014-07-01

    People who tend to engage in brooding, the maladaptive subtype of rumination, are at risk to develop depression. Brooders often endorse metacognitive beliefs that self-focused ruminative thinking is beneficial. In the current study, we examined whether brooding and positive beliefs about rumination are associated with perceptions of and preferences for treatments for depression. Participants (N=118) read descriptions of two different clusters of treatments for depression, Insight-Oriented (IO) treatments and Activation-Oriented (AO) treatments. They then rated treatment efficacy and credibility and completed self-report measures of rumination (including brooding and reflection subscales), beliefs about rumination, and depression. Brooding and metacognitive positive beliefs about rumination were associated with positive perceptions of IO (but not AO) treatments. Positive beliefs about rumination contributed to the prediction of perceptions of IO treatments (but not AO treatments) beyond the effect of brooding. We discuss the implications of these findings for individuals' decision-making processes regarding which type of treatment to seek. Copyright © 2014. Published by Elsevier Ltd.

  3. 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.

  4. Sickle cell knowledge, premarital screening and marital decisions among local government workers in Ile-Ife, Nigeria

    Directory of Open Access Journals (Sweden)

    Emmanuel A. Abioye-Kuteyi

    2009-04-01

    Full Text Available Background: In Nigeria, as in the rest of equatorial Africa, sickle cell disease (SCD has its highest incidence and continues to cause high morbidity and early death. The condition is a major public health problem among the black race. The aim of this survey is to determine the level of knowledge about SCD and the factors associated with its prevention among local government workers in Ile- Ife.Method: This is a cross-sectional descriptive study of the knowledge about SCD, attitude towards premarital sickle cell screening and marital decisions among local government workers in Ile-Ife, Nigeria, using a self-administered questionnaire.Results: 69% of study subjects had poor knowledge of SCD, while attitude towards premarital screening was favourable in 95% of the study subjects. Knowledge and attitude were significantly better among subjects with tertiary education. There was a strong positive association between attitude towards sickle cell screening and a history of undergoing screening or partner screening. Most (86.7% of the respondents and 74.0% of their partners have had sickle cell screening. One-quarter of married and engaged respondents did not know their partner’s sickle cell status. One-third to two-thirds of study subjects will continue the relationship with their partner when either or both have haemoglobinopathy.Conclusion: This study showed poor knowledge of SCD among the studied subjects. There is a need for more emphasis on health education through programmes promoting sickle cell education. In addition, the development of multifaceted patient and public health education programmes, the intensification of screening for the control of SCD by heterozygote detection, particularly during routine preplacement and premarital medical examinations, and the provision of genetic counselling to all SCD patients and carriers are vital to the identification and care of the couples at risk. These will enhance the capacity of the intending

  5. Sickle cell knowledge, premarital screening and marital decisions among local government workers in Ile-Ife, Nigeria

    Science.gov (United States)

    Oyegbade, Olanrewaju; Bello, Ibrahim; Osakwe, Chiddude

    2009-01-01

    ABSTRACT Background In Nigeria, as in the rest of equatorial Africa, sickle cell disease (SCD) has its highest incidence and continues to cause high morbidity and early death. The condition is a major public health problem among the black race. The aim of this survey is to determine the level of knowledge about SCD and the factors associated with its prevention among local government workers in Ile-Ife. Method This is a cross-sectional descriptive study of the knowledge about SCD, attitude towards premarital sickle cell screening and marital decisions among local government workers in Ile-Ife, Nigeria, using a self-administered questionnaire. Results 69% of study subjects had poor knowledge of SCD, while attitude towards premarital screening was favourable in 95% of the study subjects. Knowledge and attitude were significantly better among subjects with tertiary education. There was a strong positive association between attitude towards sickle cell screening and a history of undergoing screening or partner screening. Most (86.7%) of the respondents and 74.0% of their partners have had sickle cell screening. One-quarter of married and engaged respondents did not know their partner's sickle cell status. One-third to two-thirds of study subjects will continue the relationship with their partner when either or both have haemoglobinopathy. Conclusion This study showed poor knowledge of SCD among the studied subjects. There is a need for more emphasis on health education through programmes promoting sickle cell education. In addition, the development of multifaceted patient and public health education programmes, the intensification of screening for the control of SCD by heterozygote detection, particularly during routine preplacement and premarital medical examinations, and the provision of genetic counselling to all SCD patients and carriers are vital to the identification and care of the couples at risk. These will enhance the capacity of the intending couples to make

  6. Migrant Workers.

    Science.gov (United States)

    Social and Labour Bulletin, 1983

    1983-01-01

    Discusses a new German law to encourage foreign workers to return to their home countries, employment exchanges for young foreigners in Germany, and a training program for migrant workers in India. (SK)

  7. 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.

  8. 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.

  9. Increase in DNA damage in lymphocytes and micronucleus frequency in buccal cells in silica-exposed workers.

    Science.gov (United States)

    Halder, Ajanta; De, Madhusnata

    2012-01-01

    The alkaline single cell gel electrophoresis (comet assay) was applied to study the genotoxic properties of silica in human peripheral blood lymphocytes (PBL). The study was designed to evaluate the DNA damage of lymphocytes and the end points like micronuclei from buccal smears in a group of 45 workers, occupationally exposed to silica, from small mines and stone quarries. The results were compared to 20 sex and age matched normal individuals. There was a statistically significant difference in the damage levels between the exposed group and the control groups. The types of damages (type I -type 1V) were used to measure the DNA damage. The numbers of micronuclei were higher in the silica-exposed population. The present study suggests that the silica exposure can induce lymphocyte DNA damage and produces significant variation of micronuclei in buccal smear.

  10. 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.

  11. 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. PMID:25723540

  12. 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.

    Directory of Open Access Journals (Sweden)

    Berna Emsen

    Full Text Available 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.

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

    Science.gov (United States)

    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.

  14. 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.

  15. 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.

  16. 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

  17. Long-term effects of brood size manipulation on morphological development and sex-specific mortality of offspring

    NARCIS (Netherlands)

    DeKogel, CH

    1. Little is known about long-term effects of brood size on fitness components of offspring. This is unfortunate because such information is needed to predict optimal brood size. Furthermore, ontogenetic circumstances are potentially important in explaining the large individual differences in

  18. Contrasting brood-sex ratio flexibility in two opiine (Hymenoptera: Braconidae) parasitoids of tephritid (Diptera) fruit files

    Science.gov (United States)

    Mass-rearing of fruit fly parasitoids for augmentative release would be more economical if production could be biased towards females. If sex ratios are ever to be manipulated under rearing conditions it is important to determine if, then understand why, sex ratio flexibility exists. Unequal brood-s...

  19. Sex-specific nestling body mass in relation to brood sex composition in the Eurasian Sparrowhawk Accipiter nisus

    NARCIS (Netherlands)

    Vedder, O; Dijkstra, C; Dekker, AL; Waasdorp, S; Visser, GH

    2005-01-01

    The trade-off between brood size and offspring quality as predicted by life history theory, has been extensively studied in birds. However, in sexually size-dimorphic birds, where the larger sex requires more investment from the parents, the potential additional trade-off between brood sex ratio and

  20. Programmed Cell Death in the Honey Bee (Apis mellifera) (Hymenoptera: Apidae) Worker Brain Induced by Imidacloprid.

    Science.gov (United States)

    Wu, Yan-Yan; Zhou, Ting; Wang, Qiang; Dai, Ping-Li; Xu, Shu-Fa; Jia, Hui-Ru; Wang, Xing

    2015-08-01

    Honey bees are at an unavoidable risk of exposure to neonicotinoid pesticides, which are used worldwide. Compared with the well-studied roles of these pesticides in nontarget site (including midgut, ovary, or salivary glands), little has been reported in the target sites, the brain. In the current study, laboratory-reared adult worker honey bees (Apis mellifera L.) were treated with sublethal doses of imidacloprid. Neuronal apoptosis was detected using the TUNEL technique for DNA labeling. We observed significantly increased apoptotic markers in dose- and time-dependent manners in brains of bees exposed to imidacloprid. Neuronal activated caspase-3 and mRNA levels of caspase-1, as detected by immunofluorescence and real-time quantitative PCR, respectively, were significantly increased, suggesting that sublethal doses of imidacloprid may induce the caspase-dependent apoptotic pathway. Additionally, the overlap of apoptosis and autophagy in neurons was confirmed by transmission electron microscopy. It further suggests that a relationship exists between neurotoxicity and behavioral changes induced by sublethal doses of imidacloprid, and that there is a need to determine reasonable limits for imidacloprid application in the field to protect pollinators. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  1. Uroporphyrinogen-I-synthetase activity in red blood cells of lead-exposed workers

    Energy Technology Data Exchange (ETDEWEB)

    El-Waseef, A.

    1982-01-01

    Lead-exposed (n . 26) and control (n . 12) subjects were investigated for their blood lead concentration erythrocyte 5-amino-laevulinic acid dehydratase (5-ALAD) and erythrocyte uroporphyrinogen-I-synthetase (URO-I-S) activity; 5-amino-laevulinic acid (5-ALA) and porphobilinogen (PBG) were used as substrates in the synthetase assay. In the lead workers erythrocyte 5-ALA dehydratase was grossly inhibited but with PBG as substrate the synthetase activity was not significantly different from the control group. With 5-ALA as substrate the synthetase assay showed marked inhibition. Addition of zinc (0.1 mmol/l) and dithiotheritol (0.5 mmol/l) brought the activities of both the dehydratase and synthetase (using 5-ALA as substrate) back into the ranges seen in the control group. With porphobilinogen as substrate higher concentrations of zinc caused inhibition of the synthetase, whilst reduction of added zinc to 0.01 mmol/l resulted in stimulation of the synthetase. A good correlation (r . 0.87) was obtained in synthetase assay when PBG and 5-aminolaevulinate (with added zinc and dithiothreitol) were used as substrates. With these additions 5-ALA may be used as a substrate in the URO-I-S assay in the investigation of latent cases of acute intermittent porphyria.

  2. Persistently elevated T cell interferon-γ responses after treatment for latent tuberculosis infection among health care workers in India: a preliminary report

    OpenAIRE

    Mendiratta Deepak K; Dogra Sandeep; Joshi Rajnish; Pai Madhukar; Narang Pratibha; Dheda Keertan; Kalantri Shriprakash

    2006-01-01

    Abstract Background T cell-based interferon-γ (IFN-γ) release assays (IGRAs) are novel tests for latent tuberculosis infection (LTBI). It has been suggested that T cell responses may be correlated with bacterial burden and, therefore, IGRAs may have a role in monitoring treatment response. We investigated IFN-γ responses to specific TB antigens among Indian health care workers (HCWs) before, and after LTBI preventive therapy. Methods In 2004, we established a cohort of HCWs who underwent tube...

  3. Biased estimates of fitness consequences of brood size manipulation through correlated effects on natal dispersal

    NARCIS (Netherlands)

    Tinbergen, JM

    2005-01-01

    1. Dispersal of parents and offspring in relation to manipulated brood size were analysed in the great tit Parus major (L.) to study the potential confusion between dispersal and survival. The study area consisted of eight woodlots interspersed with nonbreeding habitat. The maximum distance between

  4. 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 Impact factor: 2.186, year: 2016

  5. The effects of brood stock size on the economy of catfish ( Clarias ...

    African Journals Online (AJOL)

    ... fry and maximum return on investment, female brooders of body weights ranging between 400 599 g are recommended for hormone induced natural breeding exercises. (International exchange rate: N129.00/US$1.00 as at 01 April, 2006) Keywords: Clarias anguillaris, brood stock size, induced breeding, fry production

  6. 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...

  7. Effect of brood size manipulations on parents and offspring in the Barn owl, Tyto alba

    NARCIS (Netherlands)

    Roulin, A; Ducrest, A.L; Dijkstra, C.

    1999-01-01

    When the overall food demand of the young increases, parents can either increase their effort to feed the brood, potentially reducing their residual reproductive value, or alternatively maintain their effort, leading to offspring mortality. In long-lived species where fitness is related to the

  8. Alternative Reproductive Tactics in the Shell-Brooding Lake Tanganyika Cichlid Neolamprologus brevis

    Directory of Open Access Journals (Sweden)

    Kazutaka Ota

    2012-01-01

    Full Text Available Alternative reproductive tactics (ARTs are found in several Lake Tanganyika shell-brooding cichlids. Field studies were conducted in the Wonzye population to examine reproductive ecology and ARTs in the Lake Tanganyika shell-brooding cichlid Neolamprologus brevis. We discovered that this fish occurred in both rocky- and sandy-bottom habitats, but in rocky habitats, brood-caring females exclusively occurred in shell-patches that another cichlid species created. All N. brevis of both sexes in the patches were sexually mature, whereas immature males and females with unripe eggs were found frequently in sandy-bottom habitats. Males in sandy-bottom habitats were smaller, but fed more frequently and were in better somatic condition than males in the patches. Similar tendency was found in females. This indicates that N. brevis uses different habitats depending on the stage of its life history, with migration from sandy-bottom habitats to the shell-patches for reproduction. Males in the patches exhibited different behavior patterns: floating above the patches and lying in the patches. The former was larger, more aggressive, and invested less in gonads (relative to body size than the latter. These results accord with those of other shell-brooding Lake Tanganyika cichlids with ARTs, and they therefore suggest the presence of ARTs in N. brevis.

  9. Physiological costs and carry-over effects of avian interspecific brood parasitism influence reproductive tradeoffs.

    Science.gov (United States)

    Mark, Melissa M; Rubenstein, Dustin R

    2013-05-01

    Although models of co-evolution between brood parasites and their hosts primarily focus upon the cost to hosts in the current reproductive bout, the impact of brood parasitism may carry over to future reproductive attempts by altering resource allocation. Glucocorticoid stress hormones help mediate resource allocation to reproduction, yet they have rarely been examined in brood parasitic systems. Here we determined if shifts in parental care and corticosterone had carry-over effects on future reproductive effort in the rufous-and-white wren (Thryophilus rufalbus), a host of the Central American striped cuckoo (Tapera naevia). We found that parasitized parents had significantly higher stress-induced, but not baseline, corticosterone than natural parents during the fledgling stage, which was associated with changes in parental care. The high investment in current reproduction while parasitized may be due to the value of fledged chicks in tropical systems. This maladaptive response by parasitized parents was associated with delayed re-nesting and a reduced likelihood of nesting in the subsequent breeding season. Although a reduction in future reproductive effort can result from a combination of factors, this work suggests that fitness costs of brood parasitism are mediated by changes in corticosterone and parental care behavior that carry over into subsequent breeding seasons. Copyright © 2013 Elsevier Inc. All rights reserved.

  10. Corticosterone metabolites in blue tit and pied flycatcher droppings: Effects of brood size, ectoparasites and temperature

    NARCIS (Netherlands)

    Lobato, E.; Merino, S.; Moreno, J.; Morales, J.; Tomás, G.; Martínez-de la Puente, J.; Osorno, J.L.; Kuchar, A.; Möstl, E.

    2008-01-01

    The hypothalamic-pituitary-adrenal (HPA) axis of birds induces the secretion of corticosterone (CORT) as a response to different ecological variables. In this study we tested experimentally if manipulations of brood size or ectoparasitism led to subsequent differences in the concentration of

  11. Interaction effect of brooding rumination and interoceptive awareness on depression and anxiety symptoms.

    Science.gov (United States)

    Lackner, Ryan J; Fresco, David M

    2016-10-01

    Awareness of the body (i.e., interoceptive awareness) and self-referential thought represent two distinct, yet habitually integrated aspects of self. A recent neuroanatomical and processing model for depression and anxiety incorporates the connections between increased but low fidelity afferent interoceptive input with self-referential and belief-based states. A deeper understanding of how self-referential processes are integrated with interoceptive processes may ultimately aid in our understanding of altered, maladaptive views of the self - a shared experience of individuals with mood and anxiety disorders. Thus, the purpose of the current study was to examine how negative self-referential processing (i.e., brooding rumination) relates to interoception in the context of affective psychopathology. Undergraduate students (N = 82) completed an interoception task (heartbeat counting) in addition to self-reported measures of rumination and depression and anxiety symptoms. Results indicated an interaction effect of brooding rumination and interoceptive awareness on depression and anxiety-related distress. Specifically, high levels of brooding rumination coupled with low levels of interoceptive awareness were associated with the highest levels of depression and anxiety-related distress, whereas low levels of brooding rumination coupled with high levels of interoceptive awareness were associated with lower levels of depression and anxiety-related distress. The findings provide further support for the conceptualization of anxiety and depression as conditions involving the integration of interoceptive processes and negative self-referential processes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Standard methods for Apis mellifera brood as human food

    DEFF Research Database (Denmark)

    Jensen, Annette Bruun; Evans, Joshua David; Jonas-Levi, Adi

    2018-01-01

    Insects hold enormous potential to address food and nutritional security issues. The honey bee is a key insect, given its importance for pollination, as well as its products which can be directly consumed, like honey, pollen and brood. Research on edible insects is an emerging field that draws up...

  13. A password for species recognition in a brood-parasitic bird.

    Science.gov (United States)

    Hauber, M E; Russo, S A; Sherman, P W

    2001-05-22

    Recognition of conspecifics is an essential precursor of sexual reproduction. Most mammals and birds learn salient features of their parents or siblings early in ontogeny and later recognize individuals whose phenotypes match the mental image (template) of relatives closely enough as conspecifics. However, the young of brood parasites are reared among heterospecifics, so social learning will yield inappropriate species recognition templates. Initially, it was inferred that conspecific recognition in brood parasites depended on genetically determined templates. More recently it was demonstrated that learning plays a critical role in the development of parasites' social preferences. Here we propose a mechanism that accommodates the interaction of learned and genetic components of recognition. We suggest that conspecific recognition is initiated when a young parasite encounters some unique species-specific signal or "password" (e.g. a vocalization, behaviour or other characteristic) that triggers learning of additional aspects of the password-giver's phenotype. We examined the possibility that nestlings of the obligately brood-parasitic brown-headed cowbird (Molothrus ater) could use a species-specific vocalization, the "chatter", as a password. We found that six-day-old nestlings responded (begged) significantly more frequently to playbacks of chatters than to other avian sounds and that two-month-old fledglings approached playbacks of chatters more quickly than vocalizations of heterospecifics. Free-living cowbird fledglings and adults also approached playbacks of chatters more often than control sounds. Passwords may be involved in the ontogeny of species recognition in brood parasites generally.

  14. 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

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

    Science.gov (United States)

    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.

  16. Post-fledging brood and care division in the roseate tern (Sterna dougallii)

    Science.gov (United States)

    Watson, M.J.; Spendelow, J.A.; Hatch, J.J.

    2012-01-01

    Extended post-fledging parental care is an important aspect of parental care in birds, although little studied due to logistic difficulties. Commonly, the brood is split physically (brood division) and/or preferential care is given to a subset of the brood by one parent or the other (care division). Among gulls and tern (Laridae), males and females generally share parental activities during the pre-fledging period, but the allocation of parental care after fledging is little documented. This study examined the behaviour of male and female roseate terns (Sterna dougallii) during the late chick-rearing and early post-fledging periods, and in particular the amount of feeds and the time spent in attendance given to individual chicks/fledglings. Pre-fledging parental care was biparental in all cases. Post-fledging parental care was dependent on the number of fledglings in the brood. Males and females continued biparental care in clutches with one surviving fledgling, while in two-fledgling clutches, males fed the A-fledgling while females fed the B-fledgling. Overall, there was no difference in attendance, only in feeds. This division of care may be influenced by the male only being certain of the paternity of the A-chick but not by chick sex. ?? 2011 Japan Ethological Society and Springer.

  17. 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

    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...

  18. Is extrapair mating random? On the probability distribution of extrapair young in avian broods

    NARCIS (Netherlands)

    Brommer, Jon E.; Korsten, Peter; Bouwman, Karen A.; Berg, Mathew L.; Komdeur, Jan

    2007-01-01

    A dichotomy in female extrapair copulation (EPC) behavior, with some females seeking EPC and others not, is inferred if the observed distribution of extrapair young (EPY) over broods differs from a random process on the level of individual offspring (binomial, hypergeometrical, or Poisson). A review

  19. Tests of landscape influence: Nest predation and brood parasitism in fragmented ecosystems

    Science.gov (United States)

    Tewksbury, J.J.; Garner, L.; Garner, S.; Lloyd, J.D.; Saab, V.; Martin, T.E.

    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 nesting success and brood parasitism in >2500 bird nests in 38 patches of deciduous riparian woodland. Patches on both river systems were embedded in one of two local contexts (buffered from agriculture by coniferous forest, or adjacent to agriculture), but the abundance of agriculture and human habitation within 1 km of each patch was highly variable. We examined evidence for three models of landscape effects on nest predation based on (1) the relative importance of generalist agricultural nest predators, (2) predators associated with the natural habitats typically removed by agricultural development, or (3) an additive combination of these two predator communities. We found strong support for an additive predation model in which landscape features affect nest predation differently at different spatial scales. Riparian habitat with forest buffers had higher nest predation rates than sites adjacent to agriculture, but nest predation also increased with increasing agriculture in the larger landscape surrounding each site. These results suggest that predators living in remnant woodland buffers, as well as generalist nest predators associated with agriculture, affect nest predation rates, but they appear to respond at different spatial scales. Brood parasitism, in contrast, was unrelated to agricultural abundance on the landscape, but showed a strong nonlinear relationship with farm and house density, indicating a critical point at which increased human habitat causes increased brood parasitism. Accurate predictions regarding landscape effects on nest predation and brood parasitism will require an

  20. High frequency of multiple paternity in broods of a socially monogamous cichlid fish with biparental nest defence.

    Science.gov (United States)

    Sefc, Kristina M; Mattersdorfer, Karin; Sturmbauer, Christian; Koblmüller, Stephan

    2008-05-01

    In several animal taxa, genetic analyses have demonstrated that social monogamy and biparental brood care do not preclude polygamous reproduction. Few studies have been conducted in fish, but in fish species without alternative reproductive phenotypes, social monogamy was largely congruent with genetic parentage. In contrast to these findings, we report an exceptionally high level of multiple paternity in a socially monogamous cichlid fish with biparental nest defence (Variabilichromis moorii), inferred from microsatellite and mitochondrial data of 10 broods. Whereas all offspring in a nest shared a common mother, each brood was sired by 2 to > 10 males. None of the inferred sires was assigned a large proportion of the brood. Paternity was estimated as the minimum number of sires required to explain multilocus offspring genotypes, and as the maximum-likelihood number of sires given population allele frequencies. Analysis of simulated brood genotypes suggested that, although these two methods tend to under- and overestimate, respectively, the true number of sires, primary sires with many offspring in a brood would have been detected. Hence, the genetic data indicate that the nest tending males suffer substantial cuckoldry and provide alloparental care for a large number of unrelated fry. We have no data on the social status of the cuckolding males, but due to synchronous spawning of pairs and commitment to brood care of paired males, it is possible that most of the parasitic spawners are solitary males.

  1. Assessment of DNA integrity (COMET assay) in sperm cells of boron-exposed workers.

    Science.gov (United States)

    Duydu, Yalçin; Başaran, Nurşen; Ustündağ, Aylin; Aydin, Sevtap; Undeğer, Ulkü; Ataman, Osman Yavuz; Aydos, Kaan; Düker, Yalçin; Ickstadt, Katja; Waltrup, Britta Schulze; Golka, Klaus; Bolt, Hermann M

    2012-01-01

    An extension of a male reproductive study conducted in a boric acid/borate production zone at Bandırma, Turkey, is presented. The relation between DNA-strand breaks (COMET assay, neutral and alkaline version) in sperm cells and previously described sperm quality parameters was investigated in boron-exposed males. A correlation between blood boron levels and mean DNA-strand breaks in sperm was weak, and DNA-strand breaks in sperm were statistically not different between control and exposed groups. Therefore, increasing boron exposures had no additional contribution in addition to already pre-existing DNA-strand breaks in the sperm cells. Weak but statistically significant correlations between DNA-strand breaks and motility/morphology parameters of sperm samples were observed in the neutral version of the COMET assay, while correlations between the same variables were statistically not significant in the alkaline version. A likely reason for these negative results, even in highly exposed humans, is that experimental exposures that had led to reproductive toxicity in animals were significantly higher than any boron exposures, which may be reached under realistic human conditions.

  2. The effects of age and past and present behavioral specialization on behavior of workers of the red wood ant Formica polyctena Först. during nestmate reunion tests.

    Science.gov (United States)

    Korczyńska, Julita; Szczuka, Anna; Symonowicz, Beata; Wnuk, Andrzej; Anna, Gonzalez Szwacka; Mazurkiewicz, Paweł Jarosław; Studnicki, Marcin; Godzińska, Ewa Joanna

    2014-09-01

    Social insect workers usually participate first in intranidal tasks and then switch to extranidal ones. However, foragers may switch again to intranidal brood care. This process is called the behavioral reversion. We applied dyadic nestmate reunion tests to explore behavioral differences between five groups of workers of the red wood ant Formica polyctena: callows (newly eclosed workers), nurses, reverted nurses (foragers that switched back to intranidal brood care in response to exposure to brood in absence of nurses), and two groups of foragers. Inter-group differences between the tested ants were related both to age and past and present behavioral specialization. Callows were the least active and their behavior was characterized by the lowest tempo. Nurses usually behaved in a way intermediate in respect to behavior of callows and the ants that had already passed the transition to extranidal tasks. The behavior of reverted nurses showed both similarities and differences with respect to behavior of foragers. Some traits of behavior of reverted nurses were similar as in the case of nurses, or intermediate in respect to both nurses and foragers. Behavioral reversion of workers of F. polyctena has thus other behavioral correlates besides the reappearance of intranidal brood care. Copyright © 2014 Elsevier B.V. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    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.

  4. Micronucleus, Nucleoplasmic Bridge, and Nuclear Budding in Peripheral Blood Cells of Workers Exposed to Low Level Benzene

    Directory of Open Access Journals (Sweden)

    I Jamebozorgi

    2016-10-01

    Full Text Available Background: Benzene is one of the important occupational pollutants. There are some reports about the leukemogenic effects related to low-level exposure to benzene. Objective: To study the frequency of micronucleus (MN, nucleoplasmic bridge (NB, and nuclear budding (NBUD in the peripheral blood lymphocytes of petrochemical workers with low level exposure to benzene. Methods: We enrolled 50 workers exposed to low-level benzene and 31 unexposed workers of a petrochemical industry. After exclusion of 3 samples, peripheral blood lymphocytes of the remaining 47 exposed and 31 unexposed workers were analyzed for the frequency of MN, NB, and NBUD by cytochalasin-blocked MN technique. Results: MN was present in 28 (60% exposed and 18 (58% unexposed workers. NB was observed in 6 (13%, and 2 (7% exposed and unexposed workers, respectively; the frequency for NBUD was 20 (43%, and 13 (42%, respectively. No significant difference was found in the observed frequencies of MN, NB, and NBUD in the peripheral blood lymphocytes between the exposed and unexposed group workers. Conclusion: Occupational exposure to low-level benzene does not increase the frequency of MN, NB, and NBUD in the peripheral blood lymphocytes, biomarkers for DNA damage.

  5. Childcare Workers.

    Science.gov (United States)

    Murphy, Ludmilla

    1986-01-01

    Discusses various aspects of the career of child-care worker: working conditions, employment possibilities, qualifications and advancement, job outlook, earnings, related occupations, and sources of additional information. (CT)

  6. 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

    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......, 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....

  7. 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.

  8. 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.

  9. 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

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

    Directory of Open Access Journals (Sweden)

    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

  11. Intraspecific brood parasitism: a strategy for floating females in the European starling.

    Science.gov (United States)

    Sandell; Diemer

    1999-01-01

    In many bird species, there is a floating population of females that are excluded from breeding because of competition for limited breeding resources. Female floaters may enhance their reproductive success by engaging in intraspecific brood parasitism. We studied female floaters in a population of European starlings, Sturnus vulgaris, in order to determine their identity and potential parasitic behaviour. Females were caught after being attracted to nestboxes with artificial nests during 1993-1995. None of the females was known to have a nest of her own at capture but 47% of the females either laid an egg in the nest or carried a fully developed egg within the reproductive tract, indicating that they were intraspecific brood parasites. The floating females were significantly younger and smaller than breeding females. Of 13 females equipped with radiotransmitters and followed daily, all but one started a breeding attempt of their own after 3-8 days and the majority settled as secondary females or mated with males where the original female had disappeared. This suggests that females that are unable to compete successfully for nest sites or males early in the breeding season may use intraspecific brood parasitism to enhance reproductive success during the period that they are constrained from breeding. The importance of settling rapidly because of a seasonal decline in reproductive success may also promote the evolution of intraspecific brood parasitism in the starling. The relative reproductive success of combining egg dumping with breeding compared with traditional breeding will depend on the costs of delaying breeding as well as the probability of finding a mate later in the breeding season. Copyright 1999 The Association for the Study of Animal Behaviour.

  12. Removal of Varroa jacobsoni infested brood in honey bee colonies with differing pollen stores

    OpenAIRE

    Janmaat, Alida; Winston, Mark

    2000-01-01

    International audience; The effects of high or low pollen storage on Apis mellifera L. brood removal behavior and Varroa jacobsoni reproduction were examined. High pollen storage colonies removed 49% of the infested larvae compared to 33% removal by the low pollen storage colonies. No difference was found in the proportion of fertile mites between those reared in high or low pollen storage colonies, although mite fertility appeared to decrease from mid to late summer in British Columbia, Cana...

  13. Brood Ball-Mediated Transmission of Microbiome Members in the Dung Beetle, Onthophagus taurus (Coleoptera: Scarabaeidae)

    Science.gov (United States)

    Estes, Anne M.; Hearn, David J.; Snell-Rood, Emilie C.; Feindler, Michele; Feeser, Karla; Abebe, Tselotie

    2013-01-01

    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 3rd 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 chamber. The

  14. Hosts improve the reliability of chick recognition by delaying the hatching of brood parasitic eggs.

    Science.gov (United States)

    Shizuka, Daizaburo; Lyon, Bruce E

    2011-03-22

    The reliability of information that animals use to make decisions has fitness consequences. Accordingly, selection should favor the evolution of strategies that enhance the reliability of information used in learning and decision making. For example, hosts of avian brood parasites should be selected to increase the reliability of the information they use to learn to recognize their own eggs and chicks. The American coot (Fulica americana), a conspecific brood parasite, uses cues learned from the first-hatched chicks of each brood to recognize and reject parasitic chicks. However, if parasitic eggs are among the first to hatch, recognition cues are confounded and parents then fail to distinguish parasitic chicks from their own chicks. Therefore, hosts could ensure correct chick recognition by delaying parasitic eggs from hatching until after the first host eggs. Here we demonstrate that discriminatory incubation, whereby coots specifically delay the hatching of parasitic eggs, improves the reliability of parasitic chick recognition. In effect, coots gain fitness benefits by enhancing the reliability of information they later use for learning. Our study shows that a positive interaction between two host adaptations in coots--egg recognition and chick recognition--increases the overall effectiveness of host defense. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. 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

    2016-12-01

    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. 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. 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.

  16. 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.

  17. Heightened exposure to parasites favors the evolution of immunity in brood parasitic cowbirds

    Science.gov (United States)

    Hahn, Caldwell; Reisen, William K.

    2011-01-01

    Immunologists and evolutionary biologists are interested in how the immune system evolves to fit an ecological niche. We studied the relationship between exposure to parasites and strength of immunity by investigating the response of two species of New World cowbirds (genus Molothrus, Icteridae), obligate brood parasites with contrasting life history strategies, to experimental arboviral infection. The South American shiny cowbird (M. bonariensis) is an extreme host-generalist that lays its eggs in the nests of >225 different avian species. The Central American bronzed cowbird (M. aeneus) is a relative host-specialist that lays its eggs preferentially in the nests of approximately 12 orioles in a single sister genus. West Nile virus provided a strong challenge and delineated immune differences between these species. The extreme host-generalist shiny cowbird, like the North American host-generalist, the brown-headed cowbird, showed significantly lower viremia to three arboviruses than related icterid species that were not brood parasites. The bronzed cowbird showed intermediate viremia. These findings support the interpretation that repeated exposure to a high diversity of parasites favors the evolution of enhanced immunity in brood parasitic cowbirds and makes them useful models for future studies of innate immunity.

  18. Patterns of avian nest predators and a brood parasite among restored riparian habitats in agricultural watersheds.

    Science.gov (United States)

    Maul, Jonathan D; Smiley, Peter C; Cooper, Charles M

    2005-09-01

    In fragmented edge-dominated landscapes, nest predation and brood parasitism may reduce avian reproductive success and, ultimately, populations of some passerine species. In the fragmented agroecosystem of northwest Mississippi, placement of drop-pipe structures has been used as a restoration technique for abating gully erosion along stream banks. These actions have formed small herbaceous and woody habitat extensions into former agricultural lands. We quantified species relative abundances, species richness, and evenness of avian nest predators and a brood parasite within four categories of constructed habitat resulting from drop-pipe installation. Differences in the abundance of two nest predators, cotton mouse (Peromyscus gossypinus) and blue jay (Cyanocitta cristata), were observed among constructed habitats. However, relative abundances of other predators such as common grackle (Quiscalus quiscula), American crow (Corvus brachyrhynchos), and hispid cotton rat (Sigmodon hispidus), and the obligate brood parasite brown-headed cowbird (Molothrus ater) did not differ among four habitat categories. Although species richness, abundance, and evenness of potential nest predators were generally similar among the constructed habitats, predator species composition varied, suggesting that these habitats supported different predator communities. This difference is important because as each predator species is added to or deleted from the community, variation may occur in the framework of prey search methods, predator strategies, and potentially overall predation pressure. We suggest that land managers using drop-pipes as part of stream restoration projects allow for the development of the constructed habitat with the largest area and greatest vegetative structure.

  19. Discovery of novel biomarkers by microarray analysis of peripheral blood mononuclear cell gene expression in benzene-exposed workers.

    Science.gov (United States)

    Forrest, Matthew S; Lan, Qing; Hubbard, Alan E; Zhang, Luoping; Vermeulen, Roel; Zhao, Xin; Li, Guilan; Wu, Yen-Ying; Shen, Min; Yin, Songnian; Chanock, Stephen J; Rothman, Nathaniel; Smith, Martyn T

    2005-06-01

    Benzene is an industrial chemical and component of gasoline that is an established cause of leukemia. To better understand the risk benzene poses, we examined the effect of benzene exposure on peripheral blood mononuclear cell (PBMC) gene expression in a population of shoe-factory workers with well-characterized occupational exposures using microarrays and real-time polymerase chain reaction (PCR). PBMC RNA was stabilized in the field and analyzed using a comprehensive human array, the U133A/B Affymetrix GeneChip set. A matched analysis of six exposed-control pairs was performed. A combination of robust multiarray analysis and ordering of genes using paired t-statistics, along with bootstrapping to control for a 5% familywise error rate, was used to identify differentially expressed genes in a global analysis. This resulted in a set of 29 known genes being identified that were highly likely to be differentially expressed. We also repeated these analyses on a smaller subset of 508 cytokine probe sets and found that the expression of 19 known cytokine genes was significantly different between the exposed and the control subjects. Six genes were selected for confirmation by real-time PCR, and of these, CXCL16, ZNF331, JUN, and PF4 were the most significantly affected by benzene exposure, a finding that was confirmed in a larger data set from 28 subjects. The altered expression was not caused by changes in the makeup of the PBMC fraction. Thus, microarray analysis along with real-time PCR confirmation reveals that altered expressions of CXCL16, ZNF331, JUN, and PF4 are potential biomarkers of benzene exposure.

  20. Brood parasitism in the sand martin, Riparia riparia: evidence for two parasitic strategies in a colonial passerine.

    Science.gov (United States)

    Alves; Bryant

    1998-12-01

    Sand martin parentage was studied at a large breeding colony in central Scotland. Multilocus DNA fingerprinting was used during the 3-year study to exclude some social parents as true parents, and thereby determine the frequency of monogamy, quasiparasitism (QP), intraspecific brood parasitism (ISBP) and extrapair fertilization (EPF) amongst 45 broods and 167 nestlings. Monogamous parentage characterized the majority of broods (60%), so most chicks were the offspring of their social parents (81%). QP (involving a male's extrapair mate laying in his nest) was found in 9% of broods and 2.4% of chicks and ISBP (or 'egg dumping') in 4% of broods and 1.8% of chicks. A substantial proportion of offspring arose from EPFs, affecting 36% of broods and 14% of chicks. On present evidence, the relatively high frequency of QP found in sand martins is unusual. We propose that its observed frequency is unlikely to be due to chance events and may represent a female-driven strategy. (c)1998 The Association for the Study of Animal Behaviour.

  1. Effects of brooding periods on performance of poults and grow-out small bronze turkeys in hot humid tropical environment.

    Science.gov (United States)

    Nwaodu, Chibuzo Hope; Okoro, Victor Mela Obinna; Uchegbu, Martins Chigozie; Mbajiorgu, Christian Anayochukwu

    2018-01-06

    A study was conducted to determine the effects of varied brooding regimes on the performance of small bronze turkey poults and their grow-outs. One hundred and twenty (n = 120) poults were subjected to four brooding regimes of 0-5, 0-6, 0-7, and 0-8 weeks, designated as T1, T2, T3, and T4. Each brooding regime (treatment) was applied to 3 replicates of 10 poults/replicate in a completely randomized design. The feed intake of T1 poults was higher (P grow-out turkeys in all the production parameters measured, as well as in the feed cost per kilogram weight gain of the treatment groups. This result shows that small bronze-type turkeys brooded from 0 to 8 weeks had higher efficiency in terms of feed intake, FCR, and lower economic costs compared to those brooded from 0 to 5, 0-6, and 0-7 weeks at the poult stage. However, at grow-out stage, the period of brooding did not have any effects on their performance.

  2. Simultaneous spawning by female stream goby Rhinogobius sp. and the association with brood cannibalism by nesting males.

    Science.gov (United States)

    Ito, S; Iwao, H; Sakata, J; Inoue, M; Omori, K; Yanagisawa, Y

    2016-09-01

    A laboratory experiment was conducted by varying the undersurface area of nesting substratum and the number of females in an experimental tank to elucidate the determinants of the mating pattern in the stream goby, Rhinogobius sp. cross-band type. Males with larger nests tended to attract two or more females to their nest in a tank. Moreover, males spawned simultaneously with multiple females and entire brood cannibalism by males was rarely observed under a female-biased sex ratio. When males spawned with a single female with low fecundity, however, entire brood cannibalism occurred at a high frequency, suggesting that a male guarding a nest with fewer eggs consumes the brood. Therefore, spawning behaviour of females that leads to a large egg mass would decrease the risk of entire brood cannibalism. In this species, simultaneous spawning by multiple females in a nest serves as a female counter-measure against entire brood cannibalism. These results suggest that a conflict of interest between the sexes through brood cannibalism is a major determinant of simultaneous spawning. © 2016 The Fisheries Society of the British Isles.

  3. Winged queens replaced by reproductives smaller than workers in Mystrium ants.

    Science.gov (United States)

    Molet, Mathieu; Peeters, Christian; Fisher, Brian L

    2007-04-01

    In ants, winged queens that are specialized for independent colony foundation can be replaced by wingless reproductives better adapted for colony fission. We studied this shift in reproductive strategy by comparing two Mystrium species from Madagascar using morphometry, allometry and dissections. Mystrium rogeri has a single dealate queen in each colony with a larger thorax than workers and similar mandibles that allow these queens to hunt during non-claustral foundation. In contrast, Mystrium 'red' lacks winged queens and half of the female adults belong to a wingless 'intermorph' caste smaller and allometrically distinct from the workers. Intermorphs have functional ovaries and spermatheca while those of workers are degenerate. Intermorphs care for brood and a few mate and reproduce making them an all-purpose caste that takes charge of both work and reproduction. However, their mandibles are reduced and inappropriate for hunting centipedes, unlike the workers' mandibles. This together with their small thorax disallow them to perform independent colony foundation, and colonies reproduce by fission. M. rogeri workers have mandibles polymorphic in size and shape, which allow for all tasks from brood care to hunting. In M. 'red', colonial investment in reproduction has shifted from producing expensive winged queens to more numerous helpers. M. 'red' intermorphs are the first case of reproductives smaller than workers in ants and illustrate their potential to diversify their caste system for better colonial economy.

  4. Migrating Worker

    DEFF Research Database (Denmark)

    Hansen, Hans

    This is the preliminary report on the results obtained in the Migrating Worker-project. This project was initiated by the Danish Ministry of Finance with the aim of illustrating the effects of the 1408/71 agreement and the bilateral double taxation agreements Denmark has with the countries included...

  5. Exploring the Link between Radiation Exposure and Multifocal Basal Cell Carcinomas in a Former Chernobyl Clean-up Worker by Combining Different Molecular Biological Techniques.

    Science.gov (United States)

    Becker, Benjamin V; Richter, Claus; Ullmann, Reinhard; Beinke, Christina; Majewski, Matthäus; Exner, Viktoria; Weisel, Guido; Abend, Michael; Port, Matthias

    2017-11-01

    Thirty years after the Chernobyl nuclear power plant accident we report on a patient who was a clean-up worker, who subsequently developed multiple cutaneous basal cell carcinomas (BCCs). We used several methods to assess the biological long-term effects related to low-dose external and internal radiation exposure. Specifically, because BCC risk may be increased with ionizing radiation exposure, we endeavored to determine whether the multifocal BCCs were related to the patient's past clean-up work. We assessed cytogenetic changes using peripheral blood, and internal incorporation was measured with a whole-body counter. Gene expression alterations were determined and array-based comparative genomic hybridization was performed for copy number aberration analysis of available BCC samples. In 1,053 metaphase cells, the dicentric yield of 0.005 dicentrics, with acentrics/cell, was significantly increased compared to the established calibration curve (P contamination was detected with the whole-body counter. At the RNA level, two of seven genes (HNRNPA1, AGAP4/6/8) indicated internal plutonium exposure associated with the lowest dose category found in Mayak workers (>0-0.055 Gy). Relevant DNA copy number changes were only detected within the most aggressive BCC focus. Our results suggest that the examined worker had low and more recent radiation exposure with presumably internalized radionuclides that were below the detection level of a whole-body counter. The multifocal BCC could not be related to past occupational radiation exposure. The findings from our study suggest that integrating different methodologies potentially provides an improved overall assessment of individual health risks associated with or excluding occupational radiation exposure.

  6. Winged queens replaced by reproductives smaller than workers in Mystrium ants

    Science.gov (United States)

    Molet, Mathieu; Peeters, Christian; Fisher, Brian L.

    2007-04-01

    In ants, winged queens that are specialized for independent colony foundation can be replaced by wingless reproductives better adapted for colony fission. We studied this shift in reproductive strategy by comparing two Mystrium species from Madagascar using morphometry, allometry and dissections. Mystrium rogeri has a single dealate queen in each colony with a larger thorax than workers and similar mandibles that allow these queens to hunt during non-claustral foundation. In contrast, Mystrium ‘red’ lacks winged queens and half of the female adults belong to a wingless ‘intermorph’ caste smaller and allometrically distinct from the workers. Intermorphs have functional ovaries and spermatheca while those of workers are degenerate. Intermorphs care for brood and a few mate and reproduce making them an all-purpose caste that takes charge of both work and reproduction. However, their mandibles are reduced and inappropriate for hunting centipedes, unlike the workers’ mandibles. This together with their small thorax disallow them to perform independent colony foundation, and colonies reproduce by fission. M. rogeri workers have mandibles polymorphic in size and shape, which allow for all tasks from brood care to hunting. In M. ‘red’, colonial investment in reproduction has shifted from producing expensive winged queens to more numerous helpers. M. ‘red’ intermorphs are the first case of reproductives smaller than workers in ants and illustrate their potential to diversify their caste system for better colonial economy.

  7. Evaluating exposure and potential effects on honeybee brood (Apis mellifera) development using glyphosate as an example

    Science.gov (United States)

    Thompson, Helen M; Levine, Steven L; Doering, Janine; Norman, Steve; Manson, Philip; Sutton, Peter; von Mérey, Georg

    2014-01-01

    This study aimed to develop an approach to evaluate potential effects of plant protection products on honeybee brood with colonies at realistic worst-case exposure rates. The approach comprised 2 stages. In the first stage, honeybee colonies were exposed to a commercial formulation of glyphosate applied to flowering Phacelia tanacetifolia with glyphosate residues quantified in relevant matrices (pollen and nectar) collected by foraging bees on days 1, 2, 3, 4, and 7 postapplication and glyphosate levels in larvae were measured on days 4 and 7. Glyphosate levels in pollen were approximately 10 times higher than in nectar and glyphosate demonstrated rapid decline in both matrices. Residue data along with foraging rates and food requirements of the colony were then used to set dose rates in the effects study. In the second stage, the toxicity of technical glyphosate to developing honeybee larvae and pupae, and residues in larvae, were then determined by feeding treated sucrose directly to honeybee colonies at dose rates that reflect worst-case exposure scenarios. There were no significant effects from glyphosate observed in brood survival, development, and mean pupal weight. Additionally, there were no biologically significant levels of adult mortality observed in any glyphosate treatment group. Significant effects were observed only in the fenoxycarb toxic reference group and included increased brood mortality and a decline in the numbers of bees and brood. Mean glyphosate residues in larvae were comparable at 4 days after spray application in the exposure study and also following dosing at a level calculated from the mean measured levels in pollen and nectar, showing the applicability and robustness of the approach for dose setting with honeybee brood studies. This study has developed a versatile and predictive approach for use in higher tier honeybee toxicity studies. It can be used to realistically quantify exposure of colonies to pesticides to allow the

  8. 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.

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

    Science.gov (United States)

    Sommer, Stefan; Whittington, Camilla M; Wilson, Anthony B

    2012-12-29

    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. 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. 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.

  10. 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

  11. A neural basis for password-based species recognition in an avian brood parasite.

    Science.gov (United States)

    Lynch, Kathleen S; Gaglio, Annmarie; Tyler, Elizabeth; Coculo, Joseph; Louder, Matthew I M; Hauber, Mark E

    2017-07-01

    Obligate avian brood parasites are raised by heterospecific hosts and, therefore, lack crucial early exposure to relatives and other conspecifics. Yet, young brood parasites readily recognize and affiliate with others of their own species upon independence. One solution to this social recognition paradox is the ontogenetic 'password' mechanism used by obligate parasitic brown-headed cowbirds (Molothrus ater), whereby conspecific identification is initially mediated through the cowbird chatter: a non-learned vocal cue. We explored the neural basis of such password-based species recognition in juvenile and adult male cowbirds. We found that cowbird auditory forebrain regions express greater densities of the protein product of the immediate-early gene ZENK in response to the password chatter call relative to control sounds of mourning dove (Zenaida macroura) coos. The chatter-selective induction of ZENK expression occurs in both the caudal medial nidopallium (NCM) and the caudal medial mesopallium (CMM) in adults, but only within the NCM in juveniles. In contrast, we discovered that juvenile cowbirds exhibit neural selectivity to presentations of either conspecific or heterospecific songs, but only in CMM and only after recent experience. Juvenile cowbirds that did not have previous experience with the song type they were exposed to during the test period exhibited significantly lower activity-dependent gene expression. Thus, in juvenile male cowbirds, there is early onset of species-specific selective neural representation of non-learned calls in NCM and recently experienced song in CMM. These results suggest that NCM is evolutionarily co-opted in parasitic cowbirds to selectively recognize the password chatter, allowing juvenile cowbirds to identify adult conspecifics and avoid mis-imprinting upon unrelated host species. These ontogenetic comparisons reveal novel insights into the neural basis of species recognition in brood parasitic species. © 2017. Published by

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

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    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.

  13. Expression of acetylcholinesterase 1 is associated with brood rearing status in the honey bee, Apis mellifera

    OpenAIRE

    Kim, Young Ho; Kim, Ju Hyeon; Kim, Kyungmun; Lee, Si Hyeock

    2017-01-01

    Acetylcholinesterase 1 (AmAChE1) of the honey bee, Apis mellifera, has been suggested to have non-neuronal functions. A systematic expression profiling of AmAChE1 over a year-long cycle on a monthly basis revealed that AmAChE1 was predominantly expressed in both head and abdomen during the winter months and was moderately expressed during the rainy summer months. Interestingly, AmAChE1 expression was inhibited when bees were stimulated for brood rearing by placing overwintering beehives in st...

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

    Science.gov (United States)

    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

  15. Mooreonuphis vespa, a new brooding species of Onuphidae (Annelida) from northern Spain (Bay of Biscay).

    Science.gov (United States)

    Arias, Andrés; Paxton, Hannelore; Anadón, Nuria

    2013-11-29

    A new species of the genus Mooreonuphis Fauchald, 1982 collected from the Cantabrian shelf (Bay of Biscay) is described. Mooreonuphis vespa sp. nov. constitutes the first record of this genus in European waters and is characterised by: conspicuous dark brown transverse segmental pigment bands; antennae and palps with 3-5 basal ceratophoral rings and a very long distal ring; unusually long and slender peristomial and dorsal cirri; simple branchiae from chaetiger 17-19. We present observations on its reproductive biology (including brooding behaviour) and remark on the biogeography of the genus.

  16. 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.

  17. 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.

  18. Mitosis and cell death in the optic lobes of workers, queens and drones of the honey bee (Apis mellifera) during metamorphosis.

    Science.gov (United States)

    Roat, Thaisa Cristina; Landim, Carminda da Cruz

    2010-09-01

    Colonies of the honey bee, Apis mellifera, consist of males and two female castes: workers and queens. The castes and males from A. mellifera have a distinct morphology, physiology and behaviour that correlate with their roles in the society and are characterized by some brain polymorphisms. Compound eyes are one of the characteristics that differ among the castes and sexes. A. mellifera is a holometabolous insect; therefore, the development of adult organs during metamorphosis, which will produce these differences, requires the precise coordination of three main programmed cellular processes: proliferation, differentiation and death. These processes take place simultaneously during pupation. Our purpose was to investigate cell division and death in the optic lobes (OL) of workers, queens and males during pupation to identify how the differences in the compound eyes in adults of these classes are achieved. The results showed that OL differentiation follows a similar pattern in the three classes of individuals studied, without structural differences in their development. The main non-structural differences involve cell division, mortality rates and timing. The results suggest a modelling of the brain during differentiation, which contributes to the specific functions of each individual class.

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

    Science.gov (United States)

    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.

  20. 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.

  1. Coevolutionary interactions between farmers and mafia induce host acceptance of avian brood parasites.

    Science.gov (United States)

    Abou Chakra, Maria; Hilbe, Christian; Traulsen, Arne

    2016-05-01

    Brood parasites exploit their host in order to increase their own fitness. Typically, this results in an arms race between parasite trickery and host defence. Thus, it is puzzling to observe hosts that accept parasitism without any resistance. The 'mafia' hypothesis suggests that these hosts accept parasitism to avoid retaliation. Retaliation has been shown to evolve when the hosts condition their response to mafia parasites, who use depredation as a targeted response to rejection. However, it is unclear if acceptance would also emerge when 'farming' parasites are present in the population. Farming parasites use depredation to synchronize the timing with the host, destroying mature clutches to force the host to re-nest. Herein, we develop an evolutionary model to analyse the interaction between depredatory parasites and their hosts. We show that coevolutionary cycles between farmers and mafia can still induce host acceptance of brood parasites. However, this equilibrium is unstable and in the long-run the dynamics of this host-parasite interaction exhibits strong oscillations: when farmers are the majority, accepters conditional to mafia (the host will reject first and only accept after retaliation by the parasite) have a higher fitness than unconditional accepters (the host always accepts parasitism). This leads to an increase in mafia parasites' fitness and in turn induce an optimal environment for accepter hosts.

  2. 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].

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

    Directory of Open Access Journals (Sweden)

    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.

  4. Alternative mechanisms of increased eggshell hardness of avian brood parasites relative to host species.

    Science.gov (United States)

    Igic, Branislav; Braganza, Kim; Hyland, Margaret M; Silyn-Roberts, Heather; Cassey, Phillip; Grim, Tomas; Rutila, Jarkko; Moskát, Csaba; Hauber, Mark E

    2011-11-07

    Obligate brood parasitic birds lay their eggs in nests of other species and parasite eggs typically have evolved greater structural strength relative to host eggs. Increased mechanical strength of the parasite eggshell is an adaptation that can interfere with puncture ejection behaviours of discriminating hosts. We investigated whether hardness of eggshells is related to differences between physical and chemical traits from three different races of the parasitic common cuckoo Cuculus canorus, and their respective hosts. Using tools developed for materials science, we discovered a novel correlate of increased strength of parasite eggs: the common cuckoo's egg exhibits a greater microhardness, especially in the inner region of the shell matrix, relative to its host and sympatric non-host species. We then tested predictions of four potential mechanisms of shell strength: (i) increased relative thickness overall, (ii) greater proportion of the structurally harder shell layers, (iii) higher concentration of inorganic components in the shell matrix, and (iv) elevated deposition of a high density compound, MgCO(3), in the shell matrix. We confirmed support only for hypothesis (i). Eggshell characteristics did not differ between parasite eggs sampled from different host nests in distant geographical sites, suggesting an evolutionarily shared microstructural mechanism of stronger parasite eggshells across diverse host-races of brood parasitic cuckoos.

  5. Enhanced innate immune responses in a brood parasitic cowbird species: degranulation and oxidative burst

    Science.gov (United States)

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

    2013-01-01

    We examined the relative effectiveness of two innate immune responses in two species of New World blackbirds (Passeriformes, Icteridae) that differ in resistance to West Nile virus (WNV). We measured degranulation and oxidative burst, two fundamental components of phagocytosis, and we predicted that the functional effectiveness of these innate immune responses would correspond to the species' relative resistance to WNV. The brown-headed cowbird (Molothrus ater), an obligate brood parasite, had previously shown greater resistance to infection with WNV, lower viremia and faster recovery when infected, and lower subsequent antibody titers than the red-winged blackbird (Agelaius phoeniceus), a close relative that is not a brood parasite. We found that cowbird leukocytes were significantly more functionally efficient than those of the blackbird leukocytes and 50% more effective at killing the challenge bacteria. These results suggest that further examination of innate immunity in the cowbird may provide insight into adaptations that underlie its greater resistance to WNV. These results support an eco-immunological interpretation that species like the cowbird, which inhabit ecological niches with heightened exposure to parasites, experience evolutionary selection for more effective immune responses.

  6. Inbreeding influences within-brood heterozygosity-fitness correlations (HFCS) in an isolated passerine population.

    Science.gov (United States)

    Townsend, Sheena M; Jamieson, Ian G

    2013-08-01

    Molecular estimates of inbreeding may be made using genetic markers such as microsatellites, however the interpretation of resulting heterozygosity-fitness correlations (HFCs) with respect to inbreeding depression is not straightforward. We investigated the relationship between pedigree-determined inbreeding coefficients (f) and HFCs in a closely monitored, reintroduced population of Stewart Island robins (Petroica australis rakiura) on Ulva Island, New Zealand. Using a full sibling design, we focused on differences in juvenile survival associated specifically with individual sibling variation in standardized multilocus heterozygosity (SH) when expected f was identical. We found that within broods, siblings with higher SH at microsatellite loci experienced a higher probability of juvenile survival. This effect, however, was detected primarily within broods that experienced inbreeding or when inbreeding had occurred in their pedigree histories (i.e., at the parents' level). Thus we show, for the first time in a wild population, that the strength of an HFC is partially dependent on the presence of inbreeding events in the recent pedigree history. Our results illustrate the importance of realized effects of inbreeding on genetic variation and fitness and the value of full-sibling designs for the study of HFCs in the context of small, inbred populations. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.

  7. 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.

  8. CaNa2EDTA chelation attenuates cell damage in workers exposed to lead--a pilot study.

    Science.gov (United States)

    Čabarkapa, A; Borozan, S; Živković, L; Stojanović, S; Milanović-Čabarkapa, M; Bajić, V; Spremo-Potparević, B

    2015-12-05

    Lead induced oxidative cellular damage and long-term persistence of associated adverse effects increases risk of late-onset diseases. CaNa2EDTA chelation is known to remove contaminating metals and to reduce free radical production. The objective was to investigate the impact of chelation therapy on modulation of lead induced cellular damage, restoration of altered enzyme activities and lipid homeostasis in peripheral blood of workers exposed to lead, by comparing the selected biomarkers obtained prior and after five-day CaNa2EDTA chelation intervention. The group of smelting factory workers diagnosed with lead intoxication and current lead exposure 5.8 ± 1.2 years were administered five-day CaNa2EDTA chelation. Elevated baseline activity of antioxidant enzymes Cu, Zn-SOD and CAT as well as depleted thiols and increased protein degradation products-carbonyl groups and nitrites, pointing to Pb induced oxidative damage, were restored toward normal values following the treatment. Lead showed inhibitor potency on both RBC AChE and BChE in exposed workers, and chelation re-established the activity of BChE, while RBC AChE remained unaffected. Also, genotoxic effect of lead detected in peripheral blood lymphocytes was significantly decreased after therapy, exhibiting 18.9% DNA damage reduction. Administration of chelation reversed the depressed activity of serum PON 1 and significantly decreased lipid peroxidation detected by the post-chelation reduction of MDA levels. Lactate dehydrogenase LDH1-5 isoenzymes levels showed evident but no significant trend of restoring toward normal control values following chelation. CaNa2EDTA chelation ameliorates the alterations linked with Pb mediated oxidative stress, indicating possible benefits in reducing health risks associated with increased oxidative damage in lead exposed populations. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  9. Group demography affects ant colony performance and individual speed of queen and worker aging.

    Science.gov (United States)

    Giehr, Julia; Heinze, Jürgen; Schrempf, Alexandra

    2017-08-01

    The performance and fitness of social societies mainly depends on the efficiency of interactions between reproductive individuals and helpers. Helpers need to react to the group's requirements and to adjust their tasks accordingly, while the reproductive individual has to adjust its reproductive rate. Social insects provide a good system to study the interrelations between individual and group characteristics. In general, sterile workers focus on brood care and foraging while the queen lays eggs. Reproductive division of labor is determined by caste and not interchangeable as, e.g., in social mammals or birds. Hence, changing social and environmental conditions require a flexible response by each caste. In the ant Cardiocondyla obscurior, worker task allocation is based on age polyethism, with young workers focusing on brood care and old workers on foraging. Here, we examine how group age demography affects colony performance and fitness in colonies consisting of only old or young workers and a single old or young queen. We hypothesized that both groups will be fully functional, but that the forced task shift affects the individuals' performance. Moreover, we expected reduced worker longevity in groups with only young workers due to precocious foraging but no effect on queen longevity depending on group composition. Neither the performance of queens nor that of workers declined strongly with time per se, but offspring number and weight were influenced by queen age and the interaction between queen and worker age. Individual residual life expectancy strongly depended on colony demography instead of physiological age. While worker age affected queen longevity only slightly, exposing old workers to the conditions of colony founding increased their life spans by up to 50% relative to workers that had emerged shortly before colony set-up. The social environment strongly affected the tempo of aging and senescence in C. obscurior, highlighting the plasticity of life

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

    Science.gov (United States)

    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.

  11. How Much of Language, If Any, Came About in the Same Sort of Way as the Brooding Chamber in Snails?

    Science.gov (United States)

    Botha, Rudolf P.

    2001-01-01

    Critically assesses the merits and limitations of four conceptions of language genesis. Focuses on the conception that language, like the brooding chamber in certain snail species, came about through cooption as a by-product of something else. (Author/VWL)

  12. First evidence of conspecific brood parasitism in song sparrows with comments on methods sufficient to document this behavior

    Science.gov (United States)

    Quresh S. Latif; J. Letitia Grenier; Sacha K. Heath; Grant Ballard; Mark E. Hauber

    2006-01-01

    Conspecific brood parasitism occurs in many songbird species but has not been reported in Song Sparrows (Melospiza melodia). In three separate study areas where breeding Song Sparrows experience heavy nest predation pressure and Brown-headed Cowbird (Molothrus ater) parasitism, we observed six instances in which newly laid eggs were attributable to female Song Sparrows...

  13. 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.

  14. 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.

  15. 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

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

    Science.gov (United States)

    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.

  17. Imprinting and the origin of parasite-host species associations in brood-parasitic indigobirds, Vidua chalybeata.

    Science.gov (United States)

    Payne; Payne; Woods; Sorenson

    2000-01-01

    Brood-parasitic village indigobirds, Vidua chalybeata, were bred in captivity and foster-reared by their normal host species, the red-billed firefinch, Lagonosticta senegala, or by an experimental foster species, the Bengalese finch, Lonchura striata. Captive-reared female indigobirds were tested as adults for mate choice and for host choice. In tests of mate choice, female indigobirds responded preferentially towards mimicry songs of male indigobirds that were similar to those of the females' own foster parents. Females reared by Bengalese finches responded to male songs that mimicked Bengalese finch song rather than to male songs that mimicked their normal host species, the firefinch. In tests of host choice, females reared by Bengalese finches laid in the nests of Bengalese finches, and females reared by firefinches laid in the nests of firefinches. Wild-caught females showed the same behaviours as captive-bred females reared by firefinches. A female indigobird's social companions (firefinch or Bengalese) following her independence of her foster parents had no effect on her sexual response to male mimicry song or her choice of a host species in brood parasitism. The results support the predictions of a model of imprinting-like behaviour development in which young indigobirds focus their attention on their foster parents, rather than a model of innate bias for songs and nests of their normal host species, or a null model of nonspecific brood parasitism and differential survival. The results provide experimental support for the recent origin of brood parasite-host associations and the significance of imprinting in speciation in these brood parasites. Copyright 2000 The Association for the Study of Animal Behaviour.

  18. 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.

  19. 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.

  20. Phylogenetic analysis reveals an evolutionary transition from internal to external brooding in Epiactis Verrill (Cnidaria: Anthozoa: Actiniaria) and rejects the validity of the genus Cnidopus Carlgren.

    Science.gov (United States)

    Larson, Paul G; Daly, Marymegan

    2016-01-01

    Reproductive behaviors in the sea anemone genus Epiactis provide an opportunity for investigating the evolution of reproductive phenomena such as brooding and sex allocation (hermaphroditic vs. gonochoric) in a group of closely related and easily accessible species. However, given its broad geographic distribution, the striking diversity in reproductive behaviors, and the lack of synapomorphy for the genus, the monophyly of Epiactis is questionable. Here we perform phylogenetic analyses to test the monophyly of Epiactis and the validity of Cnidopus, which consists entirely of species once assigned to Epiactis. We use the large number of brooding species in Epiactis to investigate evolutionary patterns in brooding modes and characteristics associated with them. We find a monophyletic group of North Pacific Epiactis species: this group includes the type species of the genus and species that brood internally or externally, and that are hermaphroditic or gonochoric. Based on the results, we reject the genus Cnidopus because its circumscription renders Epiactis sensu stricto paraphyletic. Ancestral character state reconstruction indicates that in the North Pacific, externally brooding species evolved from internally brooding ancestors and that sex allocation is highly labile. Species relationships in Epiactis and Aulactinia appear to conform to geographic patterns more strongly than to taxonomic hypotheses. Contrary to expectations based on other invertebrates, we fail to find a strong correlation between brooding and hermaphroditism. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Variation in nestmate recognition ability among polymorphic leaf-cutting ant workers.

    Science.gov (United States)

    Larsen, Janni; Fouks, Bertrand; Bos, Nick; d'Ettorre, Patrizia; Nehring, Volker

    2014-11-01

    A key feature for the success of social insects is division of labour, allowing colony members to specialize on different tasks. Nest defence is a defining task for social insects since it is crucial for colony integrity. A particularly impressive and well-known case of worker specialization in complex hymenopteran societies is found in leaf-cutting ants of the genera Atta and Acromyrmex. We hypothesized that three morphological worker castes of Acromyrmex echinatior differ in their likelihood to attack intruders, and show that major workers are more aggressive towards non-nestmate workers than medium and minor workers. Moreover, minors do not discriminate between nestmate and non-nestmate brood, while larger workers do. We further show that A. echinatior ants use cuticular chemical compounds for nestmate recognition. We took advantage of the natural variation in the cuticular compounds between colonies to investigate the proximate factors that may have led to the observed caste differences in aggression. We infer that major workers differ from medium workers in their general propensity to attack intruders (the "action component" of the nestmate recognition system), while minors seem to be less sensitive to foreign odours ("perception component"). Our results highlight the importance of proximate mechanisms underlying social insect behaviour, and encourage an appreciation of intra-colony variation when analysing colony-level traits such as nest defence. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. The Foreign Workers and Foreign Workers' German.

    Science.gov (United States)

    Blackshire-Belay, Carol

    Foreign Workers' German (FWG) refers to the acquired German language skills of workers from various countries who were recruited to West Germany between 1955 and 1973 to fill menial, undesirable jobs. Contact between these workers and native German speakers was limited because of the nature of the foreigners' work, the tendency toward residential…

  3. Parental Care in a Stressful World: Experimentally Elevated Cortisol and Brood Size Manipulation Influence Nest Success Probability and Nest-Tending Behavior in a Wild Teleost Fish.

    Science.gov (United States)

    Algera, Dirk A; Gutowsky, Lee F G; Zolderdo, Aaron J; Cooke, Steven J

    Parental care is an advantageous reproductive behavior, as the fitness of the caregiver is increased through improving the chances of its offspring's survival. Parental care occurs in a variety of teleost fishes. The body size of parental fish and the size of their brood can affect nest abandonment decisions, where compared with smaller fish with smaller broods, larger fish with larger broods typically invest more energy into reproductive events because they have less future reproductive potential. Although essential for basal metabolism and body maintenance functions, when glucocorticoid hormones (e.g., cortisol) are chronically elevated, as can occur during stress, fish may experience impairments in behavior and immune function, leading to compromised health and condition. Anthropogenic stressors during parental care can lead to elevated stress, therefore making it necessary to understand how stress influences an already-challenging period. Using smallmouth bass as a model, a gradient of body sizes, and experimentally manipulated brood size (i.e., reducing large broods and supplementing small broods) and cortisol levels (i.e., elevated via slow-release intraperitoneal cocoa butter implants containing cortisol versus controls), we tested the hypothesis that the reproductive success and parental care behaviors (i.e., aggression, nest tending) of nest-guarding male smallmouth bass are influenced by parental body size, brood size, and cortisol level. Overall, there was a relationship between cortisol treatment and nest success in which larger fish exhibited lower success when cortisol levels were elevated. Brood size had a significant effect on fish-tending behavior, independent of cortisol level and body size. Lending partial support to our hypothesis, the results of this study indicate that the reproductive success of guarding male smallmouth bass is influenced by cortisol level and that tending behavior is affected by brood size.

  4. Development rate and brood production in haplo- and pleometrotic colonies of Oecophylla smaragdina

    DEFF Research Database (Denmark)

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

    2012-01-01

    with development time, showing that earlier development of the first worker increased queen fecundity. These results indicate that pleometrotic O. smaragdina colonies are competitively superior to haplometrotic colonies as they produce more workers faster and shorten the claustral phase, leading to increased queen...

  5. 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

  6. Identification of three Halloween genes from the varroa mite and their expression during brood cell invasion

    Science.gov (United States)

    Biosynthesis of 20-hydroxyecdysone (20E) in insects involves the action of five cytochrome P450s collectively known as Halloween genes. Transcripts from 3 Halloween genes [spook (Vdspo), disembodied (Vddib) and shade (Vdshd)] from the varroa mite were identified, sequenced and mapped to their genomi...

  7. 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

  8. Community Health Worker Handbook.

    Science.gov (United States)

    Perales, Aurora Rodriguez

    An experienced community health worker describes her experiences in the field as a basis for recommended guidelines for the role, philosophy, aims, and goals of community health workers. The role of the community health worker as a member of the health care team is explored, and the problem of recognition for community health workers is considered…

  9. Assessment of Some Immune Parameters in Occupationally Exposed Nuclear Power Plants Workers: Flowcytometry Measurements of T, B, NK and NKT Cells.

    Science.gov (United States)

    Gyuleva, Ilona; Panova, Delyana; Djounova, Jana; Rupova, Ivanka; Penkova, Kalina

    2015-01-01

    The purpose of this article is to analyze the results of a 10-year survey of the radiation effects of some immune parameters of occupationally exposed personnel from the Nuclear Power Plant "Kozloduy", Bulgaria. 438 persons working in NPP with cumulative doses between 0.06 mSv and 766.36mSv and a control group with 65 persons were studied. Flow cytometry measurements of T, B, natural killer (NK) and natural killer T (NKT) cell lymphocyte populations were performed. Data were interpreted with regard to cumulative doses, length of service and age. The average values of the studied parameters of cellular immunity were in the reference range relative to age and for most of the workers were not significantly different from the control values. Low doses of ionizing radiation showed some trends of change in the number of CD3+CD4+ helper-inducer lymphocytes, CD3+ CD8+ and NKT cell counts. The observed changes in some of the studied parameters could be interpreted in terms of adaptation processes at low doses. At doses above 100-200 mSv, compensatory mechanisms might be involved to balance deviations in lymphocyte subsets. The observed variations in some cases could not be attributed only to the radiation exposure because of the impact of a number of other exogenous and endogenous factors on the immune system.

  10. The micronucleus assay in human exfoliated urothelial cells: application in a genotoxicity study of workers exposed to a mineral jelly containing sodium nitrite and N-phenyl-1-naphthylamine.

    Science.gov (United States)

    Fontana, L; Lasfargues, G; Ughetto, S; Rogier, S; Masdieu, E; Lafaure, M; Aublet-Cuvelier, B; Catilina, P

    2001-09-01

    Exposure to certain chemical agents in occupational settings has been identified as carcinogenic to the human bladder. Micronucleus (MN) analysis in exfoliated urothelial cells is an interesting method for biomonitoring genetic damage in human populations. However, few studies have been performed in an occupational context. The aim of this study was to examine whether the occupational use of a mineral jelly induced a genotoxic risk for workers employed at a single factory producing bearings using the MN test on exfoliated urothelial cells. The prevalence of micronucleated exfoliated urothelial cells (MNC) was determined in 35 female workers with dermal exposure to the jelly and 41 female controls. The mean percentage of MNC (expressed as percent cells with MN per 1000 cells scored) observed in the exposed worker group was 0.46 +/- 0.11% (range 0-2.8) and in the control group 0.14 +/- 0.03% (range 0-0.8). There is a significant job effect (P = 0.0018, MANCOVA) on the prevalence of MNC, whereas age and smoking habit had no significant effect (P = 0.90 and 0.91, respectively). There is no interaction between job and smoking habit (P = 0.4421). Exposure to the mineral jelly appeared to be the main factor inducing the increased prevalence of MNC. This may be due to the presence of mutagens/carcinogens in the jelly: an aromatic amine, N-phenyl-1-naphthylamine (CAS no. 90-30-2), which is carcinogenic in mice, or sodium nitrite (CAS no. 7632-00-0), which is genotoxic in human cell systems. In conclusion, these results suggest that use of the mineral jelly could present a genotoxic risk for workers. We think that the MN assay on exfoliated cells could be valuable for biological monitoring purposes in occupational contexts as a marker of significant exposure to bladder mutagenic/carcinogenic agents.

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

    Science.gov (United States)

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

    2015-01-01

    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

  12. 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

  13. Low CD4 T cell counts before HIV-1 seroconversion do not affect disease progression in Ethiopian factory workers

    NARCIS (Netherlands)

    Mekonnen, Yared; Geskus, Ronald B.; Hendriks, Jan C. M.; Messele, Tsehaynesh; Borghans, Jose; Miedema, Frank; Wolday, Dawit; Coutinho, Roel A.; Dukers, Nicole H. T. M.

    2005-01-01

    Background. Human immunodeficiency virus type 1 (HIV-1)-uninfected Ethiopians have lower CD4 T cell counts than do other populations in Africa and industrialized countries. We studied whether this unique immunological profile results in shorter survival times in HIV-1-infected Ethiopians. Methods.

  14. Low CD4 T cell counts before HIV-1 seroconversion do not affect disease progression in Ethiopian factory workers.

    NARCIS (Netherlands)

    Mekonnen, Y.; Geskus, R.B.; Hendriks, J.C.M.; Messele, T.; Borghans, J.; Miedema, F.; Wolday, D.; Coutinho, R.A.; Dukers, N.H.

    2005-01-01

    BACKGROUND: Human immunodeficiency virus type 1 (HIV-1)-uninfected Ethiopians have lower CD4 T cell counts than do other populations in Africa and industrialized countries. We studied whether this unique immunological profile results in shorter survival times in HIV-1-infected Ethiopians. METHODS:

  15. Intra- and interpersonal emotion regulation and adjustment symptoms in couples: The role of co-brooding and co-reappraisal

    Directory of Open Access Journals (Sweden)

    Andrea B. Horn

    2016-10-01

    Full Text Available Abstract Background Adult emotion regulation is not only occurring within the person but includes strategies that happen in social interactions and that are framed as co-regulating. The current study investigates the role of the interpersonal emotion regulation strategies of co-reappraisal and co-brooding in couples for adjustment disorder symptoms as the disorder will be outlined in the International Classification of Diseases-11 (ICD-11. Methods Couples registered together in an online questionnaire study reporting whether or not they are adjusting to a major stressor that is psychologically challenging to them. In total, one hundred and forty-six participants (N = 73 male; N = 73 female reported having experienced a major stressor in the last 12 months and were thus be identified as at risk for adjustment disorder. Those individuals at risk were assessed for adjustment disorder and depressive symptoms; intra- and interpersonal emotion regulation (co-/brooding, co-/reappraisal were assessed not only in the individual at risk but also in the romantic partner. Results Regression-based dyadic analyses revealed that above and beyond intrapersonal emotion regulation, interpersonal co-brooding and for the female participants also co-reappraisal were significantly associated with symptoms of adjustment disorder and depression, standardized betas varied between .24 and .36, suggesting medium effect sizes. An association with the female partner’s tendency to reappraise with fewer symptoms in the male partner at risk for adjustment disorder could also be observed. Conclusions Co-brooding and co-reappraisal represent emotion regulation strategies that happen in social interaction and seem to play a relevant role in the context of adjustment disorders above and beyond the commonly assessed intrapersonal emotion regulation strategies.

  16. Local cluster of germ cell cancer in a cohort of male automotive workers in Germany not explained by previous or concurrent activities and exposures in farming and forestry.

    Science.gov (United States)

    Schmeisser, N; Behrens, T; Mester, B; Gottlieb, A; Langner, I; Ahrens, W

    2011-02-01

    To examine whether exposures or activities in farming, forestry and related occupations explain the excess incidence of germ cell cancer (GCC) observed among male employees in one of the six car-manufacturing plants that is located in a geographic area where farming is frequent. A cohort based case-control study was conducted among workers in six car-manufacturing plants located in areas with different industrial structure. The study involved 188 cases of germ cell cancer identified through active retrieval in 38 hospitals and 1000 controls, drawn from administrative accounting files, individually matched by year of birth (± 2 years). Information regarding tasks and exposures and potential confounding variables were obtained by face-to-face or telephone interviews. Odds ratios (OR) and 95% confidence intervals (CI) were estimated using a conditional logistic regression model adjusted for cryptorchidism and other potential confounders. In this case-control study 5.3% of cases and 6.3% of controls ever worked in agriculture or livestock farming. No increased risks were observed for working in agriculture (OR=0.8 95% CI: 0.4-1.6), livestock farming (OR=0.8 95% CI: 0.4-1.6) or for exposure to pesticides (OR=0.7 95% CI: 0.3-1.7), for exposure to fertilizers (OR=0.8 95% CI: 0.4-1.8) and disinfectants (OR=1.0 95% CI: 0.3-2.8). There were no statistically significant increases in risk associated with ever exposure to salt based wood protection agents (OR=2.3 95% CI: 0.6-9.1), working with plywood (OR=1.4 95% CI: 0.6-3.2), coated wood (OR=1.4 95% CI: 0.5-3.9) or working in forestry (OR=1.7 95% CI: 0.5-6.4). Lagging of exposures did not alter the results. The observed excess incidence in the cohort of automotive workers can be hardly explained by previous or concurrent work in farming or forestry. Because of the small numbers of subjects ever employed in farming the statistical power in assessing associations between agricultural work and agricultural exposures was limited

  17. White-cheeked Pintail duckling and brood survival across wetland types at Humacao Nature Reserve, Puerto Rico

    Science.gov (United States)

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

    2017-01-01

    Duckling survival is an important influence on recruitment in several North American Anas species. White-cheeked Pintail (Anas bahamensis) breeding in Puerto Rico encounter a variety of wetland types that may influence duckling survival. We monitored fates of 92 radio-tagged ducklings in 31 broods in 5 wetland habitat types at Humacao Nature Reserve in southeastern Puerto Rico from 2000 to 2002. Wetlands included 2 separate coastal lagoon complexes, mangrove forest, and managed and unmanaged wetland impoundments containing herbaceous vegetation. We used known-fate models to estimate daily and interval survival rates of ducklings and broods. We conducted conservative and liberal analyses of survival because of uncertain fates of 36 ducklings. In the conservative analysis, the most parsimonious model for duckling survival contained wetland type and a positive influence of daily precipitation. In the liberal analysis, duckling survival also varied among wetlands, was positively influenced by daily precipitation, but negatively influenced by hatch date. Brood survival was also positively influenced by precipitation and female body mass. Managed wetland impoundments and shallowly flooded lagoon habitats containing ferns, interspersed cattail (Typha dominguensis), and other herbaceous cover promoted up to 3 times higher survival of ducklings over the course of a 30-day duckling period than we found in mangroves, more deeply flooded lagoons with predominately restricted shoreline cover, or unmanaged impoundments overgrown with vegetation. Broad confidence intervals for survival estimates among wetlands preclude unequivocal interpretation, but our results suggest that White-cheeked Pintail ducklings survive poorly in mangroves but benefit from appropriate management.

  18. Brooding rumination as a mediator in the relation between early maladaptive schemas and symptoms of depression and social anxiety in adolescents.

    Science.gov (United States)

    Orue, Izaskun; Calvete, Esther; Padilla, Patricia

    2014-12-01

    Theory states that different cognitive constructs can be included in an integrated sequential model. This 3-wave longitudinal study assessed whether schema domains predict brooding rumination and brooding in turn predict depression and social anxiety symptoms among adolescents. A total of 1170 adolescents (M(age) = 13.44 years old, SD(age) = 1.30) completed measures of schema domains, brooding rumination, depression and social anxiety symptoms at baseline, 6- and 12-month follow-up (T1, T2, T3, respectively). Results revealed that the Disconnection and Rejection schema domain at T1 predicted prospective depression symptoms at T3 directly but not through brooding rumination. However, this schema domain did not predict social anxiety symptoms. The Other-Directedness schema domain at T1 predicted social anxiety symptoms at T3 both directly and through brooding at T2. Furthermore, this schema domain also predicted depression symptoms at T3 through brooding at T2. Identifying specific schema domains and the mechanisms through which these domains predict psychological symptoms has implications for interventions with adolescents. Copyright © 2014 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

  19. Reproductive biology of a brooding Diopatra species: Diopatra marocensis Paxton et al., 1995

    Science.gov (United States)

    Pires, A.; Quintino, V.; Gentil, F.; Freitas, R.; Rodrigues, A. M.

    2012-09-01

    The reproductive cycle of Diopatra marocensisPaxton et al., 1995 has been studied in a population from Ria de Aveiro, Western Portugal with monthly samples, during a two-year period. This species presents a direct development with brooding in the parental tube and specimens with gametes inside the coelom and female tubes with eggs and/or larvae were observed in every sampling month. This suggested that the species reproduces during the whole year, with the main reproductive period from April to September. The male:female sex ratio ranged from 1:2 to 1:4, with females always dominating the population. A comparison with other Diopatra Audouin and Milne Edwards, 1833 (Onuphidae) showed that D. marocensis is the largest species with direct development and with the highest number of eggs and larvae inside the parental tube. With the exception of the colour, due to the presence of the gametes in the coelom cavity, no morphological differences between males and females were observed.

  20. Outbreaks of Virulent Infectious Bursal Disease in Flocks of Battery Cage Brooding System of Commercial Chickens

    Directory of Open Access Journals (Sweden)

    H. B. Aliyu

    2016-01-01

    Full Text Available Clinical and pathological investigations were conducted on outbreaks of infectious bursal disease (IBD in pullets under brooding using the battery cage system in a commercial poultry farm in Kaduna, Nigeria. Two consecutive outbreaks of IBD on the same farm were studied. The onset of the disease and morbidity and mortality rates were recorded. Postmortem examinations were conducted and gross lesions recorded. Tissues were collected and fixed in 10% buffered formalin and processed for histopathological examinations. In the first outbreak, 80 to 100% of the chicks were affected at the age of 4 to 5 weeks and mortality rate was 95.8% and lasted for 9 days. In the second outbreak, the mortality rate was 43.3% and it also lasted for 9 days. At the onset of the disease, the birds were also 4-week-old like in case 1. The disease was diagnosed based on clinical signs, pathology, and agar gel immunodiffusion test (AGID. Clinical signs, gross lesions, and histopathological findings were characteristic of virulent infectious bursal disease. After the first outbreak (case 1 the house was disinfected using polidine® (iodophor compound, V-ox® (inorganic peroxygen compounds, CID20® (quaternary ammonium chloride, aldehydes, and alcohol, terminator III® (phenols, and glutasan® (aldehyde and quaternary ammonium chloride. But they failed to eliminate the IBD virus from the poultry pen.

  1. A generalist brood parasite modifies use of a host in response to reproductive success.

    Science.gov (United States)

    Louder, Matthew I M; Schelsky, Wendy M; Albores, Amber N; Hoover, Jeffrey P

    2015-09-07

    Avian obligate brood parasites, which rely solely on hosts to raise their young, should choose the highest quality hosts to maximize reproductive output. Brown-headed cowbirds (Molothrus ater) are extreme host generalists, yet female cowbirds could use information based on past reproductive outcomes to make egg-laying decisions thus minimizing fitness costs associated with parasitizing low-quality hosts. We use a long-term (21 years) nest-box study of a single host, the prothonotary warbler (Protonotaria citrea), to show that local cowbird reproductive success, but not host reproductive success, was positively correlated with the probability of parasitism the following year. Experimental manipulations of cowbird success corroborated that female cowbirds make future decisions about which hosts to use based on information pertaining to past cowbird success, both within and between years. The within-year pattern, in particular, points to local cowbird females selecting hosts based on past reproductive outcomes. This, coupled with high site fidelity of female cowbirds between years, points to information use, rather than cowbird natal returns alone, increasing parasitism rates on highly productive sites between years. © 2015 The Author(s).

  2. Rumination in Adolescence: the Distinctive Impact of Brooding and Reflection on Psychopathology.

    Science.gov (United States)

    Xavier, Ana; Cunha, Marina; Pinto-Gouveia, José

    2016-06-20

    Rumination has a crucial role in the onset, severity and maintenance of depression in adolescent and adult populations. The Ruminative Responses Scale (RRS) is the most widely self-report instrument used to assess individual differences in the tendency to engage in ruminative responses style. This paper aims to test the factor structure of the 10-item RRS and the gender-based measurement invariance, in a community sample of adolescents, using a Confirmatory Factor Analysis. Participants were 542 adolescents (53% females) with a mean age of 14 years old (SD = 1.75) from middle and secondary schools (years of education's mean = 9.46, SD = 1.60) in Portugal. Results confirm the two-factor structure of the RRS composed by brooding and reflection dimensions (GFI = .93, CFI = .90, TLI = .87, SRMR = .05, RMSEA = .11, 90% C.I. [0.092 to 0.121]) and the invariance across gender (GFI = .91, CFI = .89, TLI = .85, RMSEA = .08, 90% C.I. [0.069 to 0.090], p anxiety and stress symptoms (p rumination than male adolescents. Overall, these findings support the usefulness of the Portuguese version of RRS and suggest that this short version is an economical, valid and reliable measure to assess ruminative response styles in adolescence.

  3. Egg eviction imposes a recoverable cost of virulence in chicks of a brood parasite.

    Directory of Open Access Journals (Sweden)

    Michael G Anderson

    Full Text Available BACKGROUND: Chicks of virulent brood parasitic birds eliminate their nestmates and avoid costly competition for foster parental care. Yet, efforts to evict nest contents by the blind and naked common cuckoo Cuculus canorus hatchling are counterintuitive as both adult parasites and large older cuckoo chicks appear to be better suited to tossing the eggs and young of the foster parents. METHODOLOGY/PRINCIPAL FINDINGS: Here we show experimentally that egg tossing imposed a recoverable growth cost of mass gain in common cuckoo chicks during the nestling period in nests of great reed warbler Acrocephalus arundinaceus hosts. Growth rates of skeletal traits and morphological variables involved in the solicitation of foster parental care remained similar between evictor and non-evictor chicks throughout development. We also detected no increase in predation rates for evicting nests, suggesting that egg tossing behavior by common cuckoo hatchlings does not increase the conspicuousness of nests. CONCLUSION: The temporary growth cost of egg eviction by common cuckoo hatchlings is the result of constraints imposed by rejecter host adults and competitive nestmates on the timing and mechanism of parasite virulence.

  4. Egg eviction imposes a recoverable cost of virulence in chicks of a brood parasite.

    Science.gov (United States)

    Anderson, Michael G; Moskát, Csaba; Bán, Miklós; Grim, Tomás; Cassey, Phillip; Hauber, Mark E

    2009-11-11

    Chicks of virulent brood parasitic birds eliminate their nestmates and avoid costly competition for foster parental care. Yet, efforts to evict nest contents by the blind and naked common cuckoo Cuculus canorus hatchling are counterintuitive as both adult parasites and large older cuckoo chicks appear to be better suited to tossing the eggs and young of the foster parents. Here we show experimentally that egg tossing imposed a recoverable growth cost of mass gain in common cuckoo chicks during the nestling period in nests of great reed warbler Acrocephalus arundinaceus hosts. Growth rates of skeletal traits and morphological variables involved in the solicitation of foster parental care remained similar between evictor and non-evictor chicks throughout development. We also detected no increase in predation rates for evicting nests, suggesting that egg tossing behavior by common cuckoo hatchlings does not increase the conspicuousness of nests. The temporary growth cost of egg eviction by common cuckoo hatchlings is the result of constraints imposed by rejecter host adults and competitive nestmates on the timing and mechanism of parasite virulence.

  5. Characterization of pollen and bacterial community composition in brood provisions of a small carpenter bee.

    Science.gov (United States)

    McFrederick, Quinn S; Rehan, Sandra M

    2016-05-01

    Many insects obtain gut microbes from their diet, but how a mother's foraging patterns influence the microbes found in her offspring's food remains an open question. To address this gap, we studied a bee that forages for pollen from multiple species of plants and may therefore acquire diverse bacteria from different plants. We tested the hypothesis that pollen diversity correlates with bacterial diversity by simultaneously characterizing these two communities in bee brood provisions for the first time. We used deep sequencing of the plant RBCL gene and the bacterial 16S rRNA gene to characterize pollen and bacterial diversity. We then tested for associations between pollen and bacterial species richness and community composition, as well as co-occurrence of specific bacteria and pollen types. We found that both pollen and bacterial communities were extremely diverse, indicating that mother bees visit a wide variety of flowers for pollen and nectar and subsequently bring a diversity of microbes back into their nests. Pollen and bacterial species richness and community composition, however, were not correlated. Certain pollen types significantly co-occurred with the most proportionally abundant bacteria, indicating that the plants these pollen types came from may serve as reservoirs for these bacteria. Even so, the overall diversity of these communities appears to mask these associations at a broader scale. Further study of these pollen and bacteria associations will be important for understanding the complicated relationship between bacteria and wild bees. © 2016 John Wiley & Sons Ltd.

  6. Extended-spectrum β-lactamase–producing Enterobacteriaceae in cell phones of health care workers from Peruvian pediatric and neonatal intensive care units

    Science.gov (United States)

    Loyola, Steev; Gutierrez, Luz R.; Horna, Gertrudis; Petersen, Kyle; Agapito, Juan; Osada, Jorge; Rios, Paul; Lescano, Andres G.; Tamariz, Jesus

    2017-01-01

    Background Health care workers (HCWs) use their mobile phones during working hours or medical care. There is evidence that the instruments are colonized with pathogenic microorganisms. Here, we describe levels of Enterobacteriaceae contamination (EC) in cell phones and the risk factors associated with EC in Peruvian intensive care units (ICUs). Methods This was a 5-month cohort study among 114 HCWs of 3 pediatric and 2 neonatology ICUs from 3 Peruvian hospitals. A baseline survey collected data on risk factors associated with EC. Swabs were collected from HCWs’ phones every other week. Results Three-quarters of HCWs never decontaminated their phones, and 47% reported using the phones in the ICU >5 times while working. EC was frequent across samplings and sites and was substantially higher in subjects with longer follow-up. Potential risk factors identified did not have strong associations with positive samples (relative risk, 0.7–1.5), regardless of significance. Half of the phones were colonized with an Enterobacteriaceae at least once during the 4 samplings attained on average during the study period. Half of the isolates were multidrug resistant (MDR), and 33% were extended-spectrum β-lactamase producers. Conclusions EC on HCWs’ phones was frequent and apparently randomly distributed through the hospitals without clear clustering or strongly associated risk factors for having a positive sample. Based on the level of EC, phones may be considered as potential bacterial reservoirs of MDR and ESBL bacteria. PMID:27067520

  7. Shift in Occupational Risk for Basal Cell Carcinoma from Outdoor to Indoor Workers: A Large Population-based Case-control Register Study from Sweden.

    Science.gov (United States)

    Lindelöf, Bernt; Lapins, Jan; Dal, Henrik

    2017-07-06

    Basal cell carcinoma (BCC) is the most common form of cancer worldwide. Exposure of the skin to ultraviolet (UV) radiation, from sunlight and other sources, is the most important risk factor. The aim of this large-scale case-control study was to determine which occupations are associated with increased risk of BCC in Sweden. The case cohort comprised 74,247 patients with BCC and the control cohort comprised 574,055 subjects linked to population-based registers. Compared with the occupational category of farmers, foresters and gardeners we observed elevated risks of BCC for almost all occupational categories studied. Legal workers with odds ratio (OR) 2.69 (95% confidence interval (CI) 2.36-3.06), dentists OR 2.69 (95% CI 2.35-3.08) and physicians OR 2.47 (95% CI 2.24-2.74) had the highest risk for both sexes taken together. In conclusion, there appears to have been a change in the risk of BCC from outdoor to indoor occupations in Sweden, possibly related to exposure to UV radiation during leisure activities exceeding occupational sun exposure as the main cause of BCC in Sweden.

  8. 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 ...

  9. Bona fide evidence for natural vertical transmission of infectious salmon anemia virus in freshwater brood stocks of farmed Atlantic salmon (Salmo salar) in Southern Chile.

    Science.gov (United States)

    Marshall, Sergio H; Ramírez, Ramón; Labra, Alvaro; Carmona, Marisela; Muñoz, Cristián

    2014-06-01

    Infectious salmon anemia (ISA) is a severe disease that affects farmed Atlantic salmon (Salmo salar), causing outbreaks in seawater in most salmon-producing countries worldwide, with particular aggressiveness in southern Chile. The etiological agent of this disease is a virus belonging to the Orthomyxoviridae family, named infectious salmon anemia virus (ISAV). Although it has been suggested that this virus can be vertically transmitted, even in freshwater, there is a lack of compelling experimental evidence to confirm this. Here we demonstrate significant putative viral loads in the ovarian fluid as well as in the eggs of two brood stock female adult specimens that harbored the virus systemically but without clinical signs. The target virus corresponded to a highly polymorphic region 3 (HPR-3) variant, which is known to be virulent in seawater and responsible for recent and past outbreaks of this disease in Chile. Additionally, the virus recovered from the fluid as well as from the interior of the eggs was fully infective to a susceptible fish cell line. To our knowledge, this is the first robust evidence demonstrating mother-to-offspring vertical transmission of the infective virus on the one hand and the asymptomatic transmission of a virulent form of the virus in freshwater fish on the other hand. The robustness of the data presented here will contribute to a better understanding of the biology of the virus but most importantly will constitute a key management tool in the control of an aggressive agent constantly threatening the sustainability of the global salmon industry.

  10. Fornecimento de substituto de pólen na redução da mortalidade de Apis mellifera L. causada pela Cria Ensacada Brasileira Pollen substitute on the reduction of Apis mellifera L. mortality caused by Brazilian Sac Brood

    Directory of Open Access Journals (Sweden)

    Guido Laércio Bragança Castagnino

    2011-10-01

    Full Text Available A cria ensacada brasileira é uma das piores enfermidades de abelhas Apis mellifera L. africanizadas, principalmente do Sudeste do Brasil. Ela afeta o desenvolvimento das larvas, após serem alimentadas pelas abelhas nutrizes com o pólen do barbatimão (Stryphnodendron polyphyllum e Stryphnodendron adstringens, ocasionando a morte entre os estágios de pré-pupa e pupa. O objetivo deste trabalho foi verificar o efeito do substituto de pólen na redução da mortalidade da cria ensacada brasileira durante o florescimento do Stryphnodendron adstringens. Foram utilizados dois tratamentos: as colmeias do tratamento 1 receberam semanalmente substituto de pólen (mistura de farinha de soja, fubá e farinha de trigo em proporções iguais. As colmeias do tratamento 2 não receberam o substituto de pólen, tendo como único alimento o pólen que encontravam na natureza. As colmeias alimentadas apresentaram diferença significativa de 93,5% de viabilidade de sobrevivência de cria em relação às não alimentadas, que apresentaram 80,4% de sobrevivência. A frequência de pólen S. adstringens nos coletores de pólen, no tratamento 1, foi 0,21. Entretanto, no Tratamento 2, foi de 4,38, indicando que as colmeias que não se alimentaram com o substituto apresentaram maior frequência do pólen dessa planta, quando comparadas com as que dispunham da dieta artificial. Esse manejo sugere que a oferta do substituto de pólen, antes e durante a florada do Stryphnodendron adstringens, é importante na redução dos efeitos da cria ensacada brasileira em enxames de abelhas africanizadas.Brazilian sac brood is one of the worst diseases of Apis mellifera L. mainly in southeast Brazil. This disease affects the larval development after having been fed with "barbatimão" pollen (Stryphnodendron polyphyllum and Stryphnodendron adstringens; the workers become intoxicated and die between the prepupae and pupae stages. This study verified the effect of pollen substitute

  11. Increase in the Th1-Cell-Based Immune Response in Healthy Workers Exposed to Low-Dose Radiation - Immune System Status of Radiology Staff

    Directory of Open Access Journals (Sweden)

    Gholamreza Karimi

    2017-06-01

    Full Text Available Objectives: Radiation is one of the most important sources of free radical (such as reactive oxygen species production, which plays an essential role in the etiology of over hundred diseases. The aim of the study was to investigate some immune parameters and hematological indices in healthy workers of the Radiology Department, University Hospital of Mashhad, Iran. Methods: The study was performed on 50 healthy workers: 30 radiology staff as the case group and 20 laboratory workers as the control group. The radiation dose received by the radiology staff participating in the study was less than the annual maximum permissible level, 50 millisievert. Hematological parameters, lymphocyte proliferation and cytokine production were studied in both groups. Results: Among healthy radiology workers, the hematological indices did not differ statistically; however, their proliferation indices and IFN-γ levels showed significant increases in parallel with decreases in the IL-4 levels as compared

  12. Effect of primer pheromones and pollen diet on the food producing glands of worker honey bees (Apis mellifera L.).

    Science.gov (United States)

    Peters, Lizette; Zhu-Salzman, Keyan; Pankiw, Tanya

    2010-02-01

    Cooperative brood care is highly developed in the honey bee such that workers called nurses use their hypopharyngeal and mandibular glands to biosynthesize proteinaceous secretions that are progressively provisioned to larvae. The role that honey bee primer pheromones play in the functional physiology of food producing glands was examined. The combined and separate effects of queen mandibular pheromone (QMP) and brood pheromone (BP) on amount of protein extractable from hypopharyngeal and mandibular glands of workers reared for 12 days with and without pollen diets was measured. In rearing environments with a pollen diet, BP, and QMP+BP pheromone treatments significantly increased extractable protein from both glands. Bees reared with QMP+pollen had amounts of protein extractable from both glands that were not significantly different from control bees (no pheromones, no pollen). Pollen in the diet alone significantly increased amounts of protein extractable from glands versus control. In rearing environments without pollen, QMP+BP had a synergizing effect on amount of protein in both glands. The QMP+BP treatment was the only rearing environment without a pollen diet where protein amounts were significantly greater than the control. The synergizing effect of QMP+BP on extractable mandibular and hypopharyngeal gland protein suggests a highly derived role for the combined effect of these two primer pheromones on honey bee cooperative brood care. Mandibular gland area was significantly and positively correlated with extractable protein. Amounts of extractable protein from both glands declined significantly with age of workers in all treatments. However, treatment significantly affected rate of decline. The adaptive significance of gland protein amounts in response to pheromones and pollen diet are discussed. Copyright 2009 Elsevier Ltd. All rights reserved.

  13. Reproductive and metabolic state differences in olfactory responses to amino acids in a mouth brooding African cichlid fish.

    Science.gov (United States)

    Nikonov, Alexandre A; Butler, Julie M; Field, Karen E; Caprio, John; Maruska, Karen P

    2017-08-15

    Olfaction mediates many crucial life-history behaviors such as prey detection, predator avoidance, migration and reproduction. Olfactory function can also be modulated by an animal's internal physiological and metabolic states. While this is relatively well studied in mammals, little is known about how internal state impacts olfaction in fishes, the largest and most diverse group of vertebrates. Here we apply electro-olfactograms (EOGs) in the African cichlid fish Astatotilapia burtoni to test the hypothesis that olfactory responses to food-related cues (i.e. l-amino acids; alanine and arginine) vary with metabolic, social and reproductive state. Dominant males (reproductively active, reduced feeding) had greater EOG magnitudes in response to amino acids at the same tested concentration than subordinate males (reproductively suppressed, greater feeding and growth rates). Mouth brooding females, which are in a period of starvation while they brood fry in their mouths, had greater EOG magnitudes in response to amino acids at the same tested concentration than both recovering and gravid females that are feeding. Discriminant function analysis on EOG magnitudes also grouped the male (subordinate) and female (recovering, gravid) phenotypes with higher food intake together and distinguished them from brooding females and dominant males. The slope of the initial negative phase of the EOG also showed intra-sexual differences in both sexes. Our results demonstrate that the relationship between olfaction and metabolic state observed in other taxa is conserved to fishes. For the first time, we provide evidence for intra-sexual plasticity in the olfactory response to amino acids that is influenced by fish reproductive, social and metabolic state. © 2017. Published by The Company of Biologists Ltd.

  14. Positive selection on sperm ion channels in a brooding brittle star: consequence of life-history traits evolution.

    Science.gov (United States)

    Weber, A A-T; Abi-Rached, L; Galtier, N; Bernard, A; Montoya-Burgos, J I; Chenuil, A

    2017-07-01

    Closely related species are key models to investigate mechanisms leading to reproductive isolation and early stages of diversification, also at the genomic level. The brittle star cryptic species complex Ophioderma longicauda encompasses the sympatric broadcast-spawning species C3 and the internal brooding species C5. Here, we used de novo transcriptome sequencing and assembly in two closely related species displaying contrasting reproductive modes to compare their genetic diversity and to investigate the role of natural selection in reproductive isolation. We reconstructed 20 146 and 22 123 genes for C3 and C5, respectively, and characterized a set of 12 229 orthologs. Genetic diversity was 1.5-2 times higher in C3 compared to C5, confirming that species with low parental investment display higher levels of genetic diversity. Forty-eight genes were the targets of positive diversifying selection during the evolution of the two species. Notably, two genes (NHE and TetraKCNG) are sperm-specific ion channels involved in sperm motility. Ancestral sequence reconstructions show that natural selection targeted the two genes in the brooding species. This may result from an adaptation to the novel environmental conditions surrounding sperm in the brooding species, either directly affecting sperm or via an increase in male/female conflict. This phenomenon could have promoted prezygotic reproductive isolation between C3 and C5. Finally, the sperm receptors to egg chemoattractants differed between C3 and C5 in the ligand-binding region. We propose that mechanisms of species-specific gamete recognition in brittle stars occur during sperm chemotaxis (sperm attraction towards the eggs), contrary to other marine invertebrates where prezygotic barriers to interspecific hybridization typically occur before sperm-egg fusion. © 2017 John Wiley & Sons Ltd.

  15. Song learning in brood-parasitic indigobirds Vidua chalybeata: song mimicry of the host species.

    Science.gov (United States)

    Payne; Payne; Woods

    1998-06-01

    Brood-parasitic village indigobirds, Vidua chalybeata, were bred in captivity and foster-reared by their normal host, red-billed firefinch, Lagonosticta senegala, or by an experimental foster species, Bengalese finch, Lonchura striata. Male indigobirds reared by Bengalese finches developed the songs of Bengalese finches, and males reared by firefinches developed songs of firefinches. Males copied their foster father only when they had lived with him long after independence (45 days post-fledging), while males separated normally at independence (22-24 days post-fledging) copied songs of other individuals and not songs of their foster father. Males reared by Bengalese finches showed no preference to learn firefinch song over songs of the experimental foster species or other control finch species even when they had lived with firefinches as companions from the time of fledging to independence. Males copied several song themes, acquired the same number of mimicry songs, and acquired their songs at the same age, whether reared by Bengalese finches or by firefinches. When they lived with other indigobirds, the male indigobirds copied mimicry songs of male indigobirds that mimicked the same foster species. We predicted mimicry-song specificity and repertoire size in experimental indigobirds from a hypothesis of an early developmental period when young indigobirds focus their attention on their foster parents, and a later period when they direct their attention to other birds with similar songs. The predictions, based on field observations of wild birds, were that (1) males reared by a novel foster species other than the normal host would learn the song of that foster species, and (2) males that left their foster parents at the normal time of independence would copy the songs of other individuals, including other adult indigobirds that mimicked the same foster species. Begging calls of young indigobirds did not mimic the calls of young firefinches. Indigobirds reared alone

  16. Early development in the mouth-brooding cichlid fish Satanoperca pappaterra (Perciformes: Cichlidae

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    Taise Miranda Lopes

    2015-03-01

    Full Text Available The Neotropical region exhibits the largest diversity of fish worldwide; however, little is known about the early development of fish species from this region. Therefore, to contribute to this knowledge, this study aimed to morphologically describe the early stages of development (eggs, larvae and juveniles of S. pappaterra using morphometric and meristic traits, and to assess changes in growth rates throughout larval and juvenile development by analyzing the relationships between various morphometric traits using analytical regression models. Both juvenile and adult individuals with mouth-brooded offspring were collected along the basins of the Cuiabá and Manso Rivers in the state of Mato Grosso, Brazil between March 2000 and March 2004. After the adults were identified, the offspring were classified according to its stage (embryonic, larval or juvenile period, and various morphometric and meristic variables were individually measured (when possible. The eggs of this species are yellow in color, oval shaped, show dendritic pigmentation within their yolk, have small to moderately sized perivitelline spaces and lack a mucous membrane and oil droplets. The horizontal and vertical diameters of the sample yolks ranged from 1.43mm to 2.70mm and 1.05mm to 1.68mm, respectively. The standard length of the larval period varied from 4.30mm to 7.16mm, and the standard length of the juvenile period varied from 10.29mm to 24.57mm. Larvae exhibit yolk sacs with internal dendritic pigmentation and dark punctate pigmentation in the dorsal and ventral body regions, whereas irregular transverse spots along the flanks are observed during the juvenile period. Adhesive organs are only present during the yolk-sac stage and at the beginning of the flexion stage. The mouth is terminal during all stages of development. The myomere number varied from 22 to 29 (9 to 16 pre-anal and 10 to 16 post-anal, and the maximal numbers of fin rays and spines were as follows: dorsal

  17. Motivating Workers in Construction

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    Jason E. Barg

    2014-01-01

    Full Text Available The study of the motivation of construction workers is limited to a relatively small body of knowledge. Although there is considerable research available regarding motivation and productivity, few researchers have provided a comprehensive analysis on the motivation of construction workers. The research stated that productivity in construction has not improved compared to other industry sectors such as manufacturing. This trend has been echoed in publications throughout the past five decades, and suggested that motivation is one of the key factors impacting productivity. This paper offers a comprehensive review of the published work that directly links the key words—construction and motivation. The findings have been presented in five themes, that is, motivation models, environment and culture, incentives and empowerment, and worker management. This paper concludes with two methods suggested by previous researchers to improve motivation of construction workers: (1 relevant worker incentives (intrinsic or extrinsic and (2 improved management practices, specifically regarding communication with workers.

  18. Worker personality and its association with spatially structured division of labor.

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    Tobias Pamminger

    Full Text Available Division of labor is a defining characteristic of social insects and fundamental to their ecological success. Many of the numerous tasks essential for the survival of the colony must be performed at a specific location. Consequently, spatial organization is an integral aspect of division of labor. The mechanisms organizing the spatial distribution of workers, separating inside and outside workers without central control, is an essential, but so far neglected aspect of division of labor. In this study, we investigate the behavioral mechanisms governing the spatial distribution of individual workers and its physiological underpinning in the ant Myrmica rubra. By investigating worker personalities we uncover position-associated behavioral syndromes. This context-independent and temporally stable set of correlated behaviors (positive association between movements and attraction towards light could promote the basic separation between inside (brood tenders and outside workers (foragers. These position-associated behavior syndromes are coupled with a high probability to perform tasks, located at the defined position, and a characteristic cuticular hydrocarbon profile. We discuss the potentially physiological causes for the observed behavioral syndromes and highlight how the study of animal personalities can provide new insights for the study of division of labor and self-organized processes in general.

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

    Science.gov (United States)

    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.

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

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    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

  1. 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.

  2. Maternal effects in the highly communal sociable weaver may exacerbate brood reduction and prepare offspring for a competitive social environment.

    Science.gov (United States)

    van Dijk, René E; Eising, Corine M; Merrill, Richard M; Karadas, Filiz; Hatchwell, Ben; Spottiswoode, Claire N

    2013-02-01

    Maternal effects can influence offspring phenotype with short- and long-term consequences. Yet, how the social environment may influence egg composition is not well understood. Here, we investigate how laying order and social environment predict maternal effects in the sociable weaver, Philetairus socius, a species that lives in massive communal nests which may be occupied by only a few to 100+ individuals in a single nest. This range of social environments is associated with variation in a number of phenotypic and life-history traits. We investigate whether maternal effects are adjusted accordingly. We found no evidence for the prediction that females might benefit from modifying brood hierarchies through an increased deposition of androgens with laying order. Instead, females appear to exacerbate brood reduction by decreasing the costly production of yolk mass and antioxidants with laying order. Additionally, we found that this effect did not depend on colony size. Finally, in accordance with an expected increased intensity of environmental stress with increasing colony size, we found that yolk androgen concentration increased with colony size. This result suggests that females may enhance the competitive ability of offspring raised in larger colonies, possibly preparing the offspring for a competitive social environment.

  3. Frequent vocalizing is negatively associated with brood parasitism in a host of the brown-headed cowbird

    Science.gov (United States)

    Steckler, Sonya E.; Conway, Courtney J.

    2012-01-01

    Brood parasitism by the Brown-headed Cowbird (Molothrus ater) can substantially affect host species' reproductive success. The "host-activity" hypothesis suggests that parasites eavesdrop on conspicuous behaviors to locate and parasitize hosts, and several studies of cowbird hosts support this hypothesis. In contrast, a recent study of the Least Bell's Vireo (Vireo bellii pusillus) reported a negative association between the host's vocalization rate near the nest and brood parasitism. This contradictory pattern is intriguing because Bell's Vireo is a common cowbird host and vocalizes near and on its nests. We tested a key assumption of the host-activity hypothesis in a different subspecies (V. b. arizonae) to determine whether the contradictory pattern reported in V. b. pusillus is an anomaly or could be generalized to other subspecies. Unparasitized vireos vocalized more frequently than parasitized birds, confirming that the pattern in Bell's Vireos is the opposite of that reported for other cowbird hosts. Nesting stage played a role: unparasitized birds vocalized more than parasitized birds only during the nest-building and incubation stages. Given that vocalization rate and other behaviors change through the breeding season, future tests of the host-activity hypothesis should control for nesting stage. Moreover, future efforts to identify the underlying cause for the association between vocalization rate and probability of parasitism should consider the possibility of reciprocal causal relationships between them. We propose five additional hypotheses to explain why in Bell's Vireo the pattern between these two traits is opposite of what has been reported in other birds.

  4. Molecular analysis of six Rhynchospio Hartman, 1936 species (Annelida: Spionidae) with comments on the evolution of brooding within the group.

    Science.gov (United States)

    Radashevsky, Vasily I; Malyar, Vasily V; Pankova, Victoria V; Nuzhdin, Sergey V

    2016-06-24

    Rhynchospio Hartman, 1936 is a small group of spionid polychaetes currently comprising ten described species distributed mainly in the Pacific. Five species examined to date are hermaphrodites producing spermatozoa with long nuclei, oocytes with thin and smooth envelopes, and dorsally brooding their offspring. Since our first molecular analysis of four Rhynchospio species, we have collected additional material from Northern Territory, Australia, and Oregon, USA. Herein, we describe the gamete and adult morphology of the newly collected material and use molecular analyses to provide new insight on the phylogenetic relationships of six Rhynchospio species. Adults of R. cf. foliosa from Oregon are hermaphrodites, but in contrast to other Rhynchospio, they produce spermatozoa with short nuclei (ect-aquasperm), oocytes with thick vesiculate envelopes, and likely have a holopelagic larval development. Analysis of four gene fragments, comprising mitochondrial 16S rDNA, and nuclear 18S, 28S rDNA, and Histone 3 (2516 bp in total) showed Rhynchospio to be a monophyletic group, with R. cf. foliosa being a distant sister to the five other species. Rhynchospio cf. foliosa was closer to M. arctia having ect-aquasperm and vesiculate thick-envelop oocytes (p = 14.40%) than to Spioninae members B. proboscidea and P. elegans, having introsperm and oocytes with thin and smooth envelopes (p = 15.39 and 16.54%, respectively). We hypothesize that brooding might have evolved from free-spawning inside the Rhynchospio clade, but this hypothesis should be tested in a future analysis.

  5. Mortality among rubber workers: V. processing workers.

    Science.gov (United States)

    Delzell, E; Monson, R R

    1982-07-01

    Cause-specific mortality was evaluated among 2,666 men employed in the processing division of a rubber manufacturing plant. The division was divided into two sections: front processing (compounding, mixing and milling operations) and back processing (extrusion, calendering, cement mixing and rubberized fabrics operations). Mortality rates for all processing workers combined and for men in each section were compared with rates for U.S. White males or for workers employed in other divisions of the same plant. Compared with either referent group, men in the processing division had increased mortality from leukemia, emphysema, and cancers of the stomach, large intestine, and biliary passages and liver. An excess number of deaths from stomach and larger intestine cancer was found predominantly among men in the front processing section (33 observed vs. 17.7 expected deaths, based on rates in nonprocessing workers). Increased mortality from leukemia (14 observed vs. 7.3 expected) and from emphysema (22 observed vs. 11.0 expected) was present among men employed in the back processing section. Examination of mortality from these causes according to age and the year starting work, duration of employment, and years since starting work in the relevant sections of the processing division suggested that observed excesses of stomach cancer, large intestine cancer, leukemia, and emphysema among processing workers are related to occupational exposures. These results are consistent with the findings of studies of other groups of rubber workers.

  6. Abbreviation of larval development and extension of brood care as key features of the evolution of freshwater Decapoda.

    Science.gov (United States)

    Vogt, Günter

    2013-02-01

    The transition from marine to freshwater habitats is one of the major steps in the evolution of life. In the decapod crustaceans, four groups have colonized fresh water at different geological times since the Triassic, the freshwater shrimps, freshwater crayfish, freshwater crabs and freshwater anomurans. Some families have even colonized terrestrial habitats via the freshwater route or directly via the sea shore. Since none of these taxa has ever reinvaded its environment of origin the Decapoda appear particularly suitable to investigate life-history adaptations to fresh water. Evolutionary comparison of marine, freshwater and terrestrial decapods suggests that the reduction of egg number, abbreviation of larval development, extension of brood care and lecithotrophy of the first posthatching life stages are key adaptations to fresh water. Marine decapods usually have high numbers of small eggs and develop through a prolonged planktonic larval cycle, whereas the production of small numbers of large eggs, direct development and extended brood care until the juvenile stage is the rule in freshwater crayfish, primary freshwater crabs and aeglid anomurans. The amphidromous freshwater shrimp and freshwater crab species and all terrestrial decapods that invaded land via the sea shore have retained ocean-type planktonic development. Abbreviation of larval development and extension of brood care are interpreted as adaptations to the particularly strong variations of hydrodynamic parameters, physico-chemical factors and phytoplankton availability in freshwater habitats. These life-history changes increase fitness of the offspring and are obviously favoured by natural selection, explaining their multiple origins in fresh water. There is no evidence for their early evolution in the marine ancestors of the extant freshwater groups and a preadaptive role for the conquest of fresh water. The costs of the shift from relative r- to K-strategy in freshwater decapods are traded

  7. Are Social Workers Homophobic?

    Science.gov (United States)

    Wisniewski, Jack J.; Toomey, Beverly G.

    1987-01-01

    Describes a study of attitudes towards homosexuality in representative sample of social workers (N=77) in Columbus, Ohio using Hudson's Index of Attitudes toward Homosexuals. Results lend preliminary empirical support to the implied assumption that social workers manifest signs of homophobia. (ABL)

  8. Workers' Education in Palestine

    Science.gov (United States)

    Elayassa, Wajih

    2013-01-01

    Due to the political context and the restrictions placed on general freedoms and trade union activities, workers' education in Palestine remained informal and largely reliant on oral memory until the early 1990s. For decades, it was an integral part of political education. Workers' education only became a stand-alone field after the establishment…

  9. What makes workers happy?

    NARCIS (Netherlands)

    van der Meer, P.H.; Wielers, R.J.J.

    2013-01-01

    This article answers the question what makes workers happy? It does so by combining insights from micro-economics, sociology and psychology. Basis is the standard utility function of a worker that includes income and hours of work and is elaborated with job characteristics. In this way it is

  10. Special Issue: Rural Workers.

    Science.gov (United States)

    Goodson, Elizabeth; And Others

    1995-01-01

    The issue discusses the role of the International Labour Office in the field of workers' education for rural workers and their organizations. Articles discuss labor conditions, child labor in agriculture, gender and equality training, trade unions, fair trade, and changing patterns of food production. Appendixes include information about…

  11. 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

    Directory of Open Access Journals (Sweden)

    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

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

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    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

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

    Science.gov (United States)

    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...

  14. 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

  15. Declining brown-headed cowbird (Molothrus ater) populations are associated with landscape-specific reductions in brood parasitism and increases in songbird productivity

    Science.gov (United States)

    W. Andrew Cox; Frank R., III Thompson; Brian Root; John Faaborg; Csaba. Moskat

    2012-01-01

    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...

  16. Did vicariance and adaptation drive cryptic speciation and evolution of brooding in Ophioderma longicauda (Echinodermata: Ophiuroidea), a common Atlanto-Mediterranean ophiuroid?

    Science.gov (United States)

    Boissin, E; Stöhr, S; Chenuil, A

    2011-11-01

    Over the last decade, cryptic speciation has been discovered in an increasing number of taxa. Species complexes are useful models for the understanding of speciation processes. Motivated by the discovery of brooding specimens in the common Atlanto-Mediterranean broadcast spawning brittle star, Ophioderma longicauda, a recent study revealed the occurrence of divergent mitochondrial lineages. We analysed 218 specimens from 23 locations spread over the geographic range of the species with partial Cytochrome c Oxidase subunit I (COI) sequences. A subset of this sample was also surveyed with the internal transcribed spacer of the ribosomal DNA cluster (nuclear ITS-1). Our study revealed six highly divergent mitochondrial lineages, and the ITS-1 data confirmed that they most likely represent a species complex. Geographic ranges, abundances and genetic structures are contrasted among the putative cryptic species. Lineages in which brooding specimens have been found form a monophyletic group and are restricted to the Eastern Mediterranean basin, an oligotrophic zone. A phylogeny-trait association analysis revealed a phylogenetic signal for low 'chlorophyll a' values (our proxy for oligotrophy). An ecological shift related to the hyper oligotrophy of the Eastern Mediterranean region is therefore likely to have played a role in the evolution of brooding. This study revealed that a complex mixture of vicariance, population expansion, adaptive divergence and possibly high local diversification rates resulting from brooding has shaped the evolution of this species complex. The dating analysis showed that these events probably occurred in the Pleistocene epoch. © 2011 Blackwell Publishing Ltd.

  17. [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)

    Science.gov (United States)

    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.

  18. 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.

  19. Gonococcal cervicitis is associated with reduced systemic CD8+ T cell responses in human immunodeficiency virus type 1-infected and exposed, uninfected sex workers.

    Science.gov (United States)

    Kaul, Rupert; Rowland-Jones, Sarah L; Gillespie, Geraldine; Kimani, Joshua; Dong, Tao; Kiama, Peter; Simonsen, J Neil; Bwayo, Job J; McMichael, Andrew J; Plummer, Francis A

    2002-05-15

    Neisseria gonorrhoeae cervicitis and human immunodeficiency virus (HIV) type 1 frequently coinfect core transmitter populations, such as female sex workers. Gonococcal cervicitis is associated with increased viral shedding and plasma viremia in HIV-1-infected women and increased HIV-1 susceptibility in uninfected women. We studied the influence of gonococcal cervicitis on CD8(+) interferon (IFN)-gamma responses to HIV-1 and cytomegalovirus (CMV) epitopes in HIV-1-infected and in highly-exposed, persistently seronegative (HEPS) female sex workers. In HIV-1-infected women, gonococcal cervicitis was associated with reduced IFN-gamma responses in bulk CD8(+) lymphocyte populations, and intracellular cytokine staining, combined with class I major histocompatibility complex (MHC)-peptide tetramer studies, demonstrated reduced IFN-gamma production by HIV-1 epitope-specific CD8(+) lymphocytes. In HEPS sex workers, cervicitis was associated with the transient loss of systemic HIV-1-specific CD8(+) responses and with reduced function of CMV-specific CD8(+) lymphocytes. Impaired function of virus-specific CD8(+) lymphocytes may partly explain the deleterious effects of gonococcal cervicitis on HIV-1 immune control and susceptibility.

  20. Asthma among mink workers

    DEFF Research Database (Denmark)

    Grøntved, Berit; Carstensen, Ole; Petersen, Rolf

    2014-01-01

    We report two cases of asthma among mink workers. The first case is about a mink farmer who had asthma that was difficult to treat. In the medical history there was no clear relation to work, and no conclusive work relation with peak flow monitoring. He had a positive histamine release test to mink...... urine. The second case is about a mink farm worker, who had an asthma attack when handling mink furs. Peak flow monitoring showed a clear relation to this work, but there were no signs of allergy. We conclude that these two cases suggest an increased risk of asthma among mink workers....

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

    Science.gov (United States)

    Benowitz-Fredericks, Z.M.; Kitaysky, Alexander S.; Welcker, Jorg; Hatch, Scott A.

    2013-01-01

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  3. Nutritional balance of essential amino acids and carbohydrates of the adult worker honeybee depends on age.

    Science.gov (United States)

    Paoli, Pier P; Donley, Dion; Stabler, Daniel; Saseendranath, Anumodh; Nicolson, Susan W; Simpson, Stephen J; Wright, Geraldine A

    2014-06-01

    Dietary sources of essential amino acids (EAAs) are used for growth, somatic maintenance and reproduction. Eusocial insect workers such as honeybees are sterile, and unlike other animals, their nutritional needs should be largely dictated by somatic demands that arise from their role within the colony. Here, we investigated the extent to which the dietary requirements of adult worker honeybees for EAAs and carbohydrates are affected by behavioural caste using the Geometric Framework for nutrition. The nutritional optimum, or intake target (IT), was determined by confining cohorts of 20 young bees or foragers to liquid diets composed of specific proportions of EAAs and sucrose. The IT of young, queenless bees shifted from a proportion of EAAs-to-carbohydrates (EAA:C) of 1:50 towards 1:75 over a 2-week period, accompanied by a reduced lifespan on diets high in EAAs. Foragers required a diet high in carbohydrates (1:250) and also had low survival on diets high in EAA. Workers exposed to queen mandibular pheromone lived longer on diets high in EAA, even when those diets contained 5× their dietary requirements. Our data show that worker honeybees prioritize their intake of carbohydrates over dietary EAAs, even when overeating EAAs to obtain sufficient carbohydrates results in a shorter lifespan. Thus, our data demonstrate that even when young bees are not nursing brood and foragers are not flying, their nutritional needs shift towards a diet largely composed of carbohydrates when they make the transition from within-hive duties to foraging.

  4. Workers Compensation Claim Data -

    Data.gov (United States)

    Department of Transportation — This data set contains DOT employee workers compensation claim data for current and past DOT employees. Types of data include claim data consisting of PII data (SSN,...

  5. Motivating the Knowledge Worker

    Science.gov (United States)

    2010-01-01

    important. Herzberg . The Two-factor Theory asserts that motivators and de- motivators are mutually exclusive sets of factors. This research supports... MOTIVATING THE KNOWLEDGE WORKER David E. Frick Commonly accepted economic theory suggests that workers are rational actors and make decisions that...what ignites your passion and the passion of those around you” (p. 109). Public Service Motivation Theory (Crewson, 1997; Houston, 2000; Perry

  6. 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.

  7. Induced sputum evaluation in microwave popcorn production workers.

    Science.gov (United States)

    Akpinar-Elci, Muge; Stemple, Kimberly J; Enright, Paul L; Fahy, John V; Bledsoe, Toni A; Kreiss, Kathleen; Weissman, David N

    2005-08-01

    Severe airways obstruction and bronchiolitis obliterans have been reported in microwave popcorn production workers and attributed to inhalation of flavoring agents. We investigated whether exposure to flavoring agents is associated with airways inflammation in popcorn production workers. Fifty-nine workers with high exposures and 22 patients with low exposures to flavoring vapors completed a questionnaire, spirometry, and sputum induction. Sputum cell counts were categorized as "high" if greater than (and "low" if less than or equal to) the median cell counts of a healthy external control group (n = 24). We compared high- and low-exposure groups as well as all workers with control subjects. Neutrophil concentrations in nonsmoking workers were significantly higher than those of the healthy nonsmoking control group (p 1.63 x 10(5)/mL) was 3.8 (95% confidence interval, 1.3 to 11.5) in the high-exposure group compared with the low-exposure group. Sputum interleukin-8 and eosinophil cationic protein levels were higher in high-exposure workers than in low-exposure workers (p 95%. There were no relationships between sputum characteristics and the presence of airways obstruction. High exposure to popcorn flavoring agents is associated with neutrophilic airway inflammation in popcorn production workers. These data provide further evidence that popcorn production workers face a significant occupational hazard through exposure to flavoring agents.

  8. 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

  9. Evaluation of toxicological biomarkers in secreted proteins of HepG2 cells exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin and their expressions in the plasma of rats and incineration workers.

    Science.gov (United States)

    Phark, Sohee; Park, So-Young; Chang, Yoon-Seok; Choi, Seonyoung; Lim, Ji-youn; Kim, Yoonjin; Seo, Jong Bok; Jung, Woon-Won; Sul, Donggeun

    2016-05-01

    Toxicological biomarkers of 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) were investigated in proteins secreted by HepG2 cells and their expression levels were determined in the plasma of rats exposed to 2,3,7,8-TCDD and in the plasma of incineration workers exposed to dioxins. HepG2 cells were treated with various concentrations of 2,3,7,8-TCDD (0, 0.25, 0.5, 1, 2.5, 5, 10, 25 nM) for 24 or 48 h. MTT and Comet assays were performed to determine cytotoxicities and genotoxicities to select exposure concentrations for the proteomic analysis of proteins secreted by 2,3,7,8-TCDD-treated cells. In the proteomic analysis, dose- and time-dependent toxicological biomarkers were evaluated using two pI ranges (4-7 and 6-9) using a large gel 2-DE system. Fifteen secreted proteins were identified by a nano-LC-ESI-MS/MS and nano-ESI on a Q-TOF2 MS and the identities of eight secreted proteins including glyoxalase 1 (GLO 1), homogentisate dioxygenase (HGD), peroxiredoxin 1 (PRX 1), proteasome subunit beta type (PSMB) 5 and 6, UDP-glucose 6-dehydrogenase (UDP-GlcDH), hydroxyacyl-coenzyme A dehydrogenase (HADH) and serotransferrin (STF) were confirmed by western blotting. Of these, PSMB 5 and PRX 1 were also found in the plasma of rats exposed to 2,3,7,8-TCDD, whereas GLO 1, HGD, PSMB 6 and PRX 1 were found in the plasma of incineration workers exposed to dioxins. Copyright © 2016. Published by Elsevier B.V.

  10. 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

  11. Migration of health workers.

    Science.gov (United States)

    Buchan, James

    2008-01-01

    The discussion and debate stimulated by these papers focused across a range of issues but there were four main areas of questioning: "measuring" and monitoring migration (issues related to comparability, completeness and accuracy of data sets on human resources); the impact of migration of health workers on health systems; the motivations of individual health workers to migrate (the "push" and "pull" factors) and the effect of policies designed either to reduce migration (e.g "self ufficiency") or to stimulate it (e.g active international recruitment). It was recognised that there was a critical need to examine migratory flows within the broader context of all health care labour market dynamics within a country, that increasing migration of health workers was an inevitable consequence of globalisation, and that there was a critical need to improve monitoring so as to better inform policy formulation and policy testing in this area.

  12. Co-Brooding and Co-Reflection as Differential Predictors of Depressive Symptoms and Friendship Quality in Adolescents: Investigating the Moderating Role of Gender.

    Science.gov (United States)

    Bastin, Margot; Vanhalst, Janne; Raes, Filip; Bijttebier, Patricia

    2017-10-06

    Co-rumination has been shown advantageous for friendship quality, but disadvantageous for mental health. Recently, two components have been distinguished, with co-brooding predicting increases in depressive symptoms and co-reflection decreases. The current study aimed to replicate these findings and investigated whether both components also show differential relations with friendship quality. Gender was investigated as a moderator. Path analyses were used on data of 313 adolescents aged 9-17 (50.5% girls). Co-brooding was related to more concurrent and prospective depressive symptoms in girls. Co-reflection predicted less concurrent and prospective depressive symptoms in girls and higher concurrent positive friendship quality for boys and girls. This study underscores the value of studying co-rumination components and suggests that boys and girls in this context differ in their pathways towards depression.

  13. 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

    when the bee is not in the nest. The nest parasite often oviposited through the additional cell closure but its offspring were then trapped in the empty cell and starved to death. 4. Only 5.4% of the inner brood cells that were protected by an empty cell were parasitised, compared with 28.9% of those...

  14. A dataset describing brooding in three species of South African brittle stars, comprising seven high-resolution, micro X-ray computed tomography scans.

    Science.gov (United States)

    Landschoff, Jannes; Du Plessis, Anton; Griffiths, Charles L

    2015-01-01

    Brooding brittle stars have a special mode of reproduction whereby they retain their eggs and juveniles inside respiratory body sacs called bursae. In the past, studying this phenomenon required disturbance of the sample by dissecting the adult. This caused irreversible damage and made the sample unsuitable for future studies. Micro X-ray computed tomography (μCT) is a promising technique, not only to visualise juveniles inside the bursae, but also to keep the sample intact and make the dataset of the scan available for future reference. Seven μCT scans of five freshly fixed (70 % ethanol) individuals, representing three differently sized brittle star species, provided adequate image quality to determine the numbers, sizes and postures of internally brooded young, as well as anatomy and morphology of adults. No staining agents were necessary to achieve high-resolution, high-contrast images, which permitted visualisations of both calcified and soft tissue. The raw data (projection and reconstruction images) are publicly available for download from GigaDB. Brittle stars of all sizes are suitable candidates for μCT imaging. This explicitly adds a new technique to the suite of tools available for studying the development of internally brooded young. The purpose of applying the technique was to visualise juveniles inside the adult, but because of the universally good quality of the dataset, the images can also be used for anatomical or comparative morphology-related studies of adult structures.

  15. New evidence of brooding in the deep-sea brittle star Astrotoma agassizii Lyman, 1876 from a South Western Atlantic Canyon

    Science.gov (United States)

    Berecoechea, Juan José; Brogger, Martín I.; Penchaszadeh, Pablo E.

    2017-09-01

    The reproduction of the brittle star Astrotoma agassizii was studied from deep waters of the South Atlantic Ocean, based on samples collected in August 2012, and May and September 2013. Ten samples from 800 to 1400 m depths off Mar del Plata Canyon were studied. The species was found to be a brooding simultaneous hermaphrodite. Hermaphroditic gonads contained testis and ovaries inside the same sacs. Both, ovary and testis contained different stages of gametogenesis development simultaneously. Gonads contained several stages of oocytes in different stages of gametogenesis. The largest oocyte recorded was 800 μm diameter. Free spermatozoa were observed in the lumen of the testis, together with spermatogenic columns. Five individuals, from a total of 30 examined, resulted brooding, and most contained mature ovotestis at the same time. Incubation occurs in five of the ten bursal sacs, containing 15-20 young juveniles each. Maximum disc diameter recorded for a brood was 1100 μm. Herein we hypothesize that Astrotoma agassizii could be continuous breeder species in the deep-sea.

  16. Reef scent: How brooded coral larvae from a tough coral smell their way to a new home

    Science.gov (United States)

    Spies, N.; Richmond, R. H.; Seneca, F.; Murphy, J.; Martinez, J.; Lyman, A.

    2016-02-01

    Coral reefs are highly diverse marine ecosystems of ecological, economic, and cultural value. With the expected negative effects on reefs from global climate change including rising sea temperatures and ocean acidification, the identification of resilient coral species has become increasingly important. Leptastrea purpurea is an encrusting coral that is found throughout the Indo-Pacific and Red Sea. While most corals are broadcast spawners, releasing sperm and eggs to be fertilized in the water column, some corals brood embryos within their tissues after internal fertilization. L. purpurea appears to release planula larvae on a continuous basis from the parent colony as observed during two years of monitoring. The planula larvae show remarkable resilience under a wide range of stressful conditions including temperature, sediment, and chemical stressors, as well as the ability to successfully settle and metamorphose after 180 days in controlled laboratory conditions. Various smells were tested to identify a settlement cue for L. purpurea larvae, and our results suggest that the smell associated with other coral colonies induce larval settlement and metamorphosis. Knowledge of the settlement cues and reproductive biology of this coral is important to our understanding of coral resilience in the face of anthropogenic perturbation.

  17. The relationship between morphological and sexual indices in suitable brood Russian sturgeon Acipenser gueldenstaedtii (Brandt and Ratzeburg, 1833

    Directory of Open Access Journals (Sweden)

    Bahram Falahatkar

    2014-09-01

    Full Text Available Owing to reduction of sturgeon stocks in various water bodies, artificial propagation has become significantly important for stock restoration and appropriate broodstock selection is vital in this process. Selection of suitable broodstocks may influence the quality and quantity of obtained eggs and larva. The present study aimed to examine correlation between some morphometric and reproductive parameters to find suitable brood fish for artificial reproduction in Russian sturgeon, Acipenser gueldenstaedtii. Forty fish free of any external disease symptom and abnormality were selected for the study. Following biometric measurements including weight, total length, abdominal girth, PV (distance between pectoral and pelvic fins, LX (distance between anal and caudal fins, polarization index (PI, gonadosomatic index, absolute fecundity, and fertilization rate, correlations between these morphometric and biological characteristics with emphasis on breeding were calculated. There was higher correlation between weight-absolute fecundity and length-PV in fish responded to artificial breeding, while correlation between age-PV, length-PV and weight-abdominal girth were higher in those fish not responded to artificial breeding. The results suggests that it is quite possible to select suitable Russian sturgeon spawners for artificial propagation based on combination of body weight, LX, PV, age, abdominal girth and total length, however the most useful criteria for the selection seems to be precise measurement of the polarization index.

  18. Elucidating the multiple genetic lineages and population genetic structure of the brooding coral Seriatopora (Scleractinia: Pocilloporidae) in the Ryukyu Archipelago

    Science.gov (United States)

    Nakajima, Yuichi; Nishikawa, Akira; Iguchi, Akira; Nagata, Tomofumi; Uyeno, Daisuke; Sakai, Kazuhiko; Mitarai, Satoshi

    2017-06-01

    The elucidation of species diversity and connectivity is essential for conserving coral reef communities and for understanding the characteristics of coral populations. To assess the species diversity, intraspecific genetic diversity, and genetic differentiation among populations of the brooding coral Seriatopora spp., we conducted phylogenetic and population genetic analyses using a mitochondrial DNA control region and microsatellites at ten sites in the Ryukyu Archipelago, Japan. At least three genetic lineages of Seriatopora (Seriatopora-A, -B, and -C) were detected in our specimens. We collected colonies morphologically similar to Seriatopora hystrix, but these may have included multiple, genetically distinct species. Although sexual reproduction maintains the populations of all the genetic lineages, Seriatopora-A and Seriatopora-C had lower genetic diversity than Seriatopora-B. We detected significant genetic differentiation in Seriatopora-B among the three populations as follows: pairwise F ST = 0.064-0.116 (all P = 0.001), pairwise G''ST = 0.107-0.209 (all P = 0.001). Additionally, only one migrant from an unsampled population was genetically identified within Seriatopora-B. Because the peak of the settlement of Seriatopora larvae is within 1 d and almost all larvae are settled within 5 d of spawning, our observations may be related to low dispersal ability. Populations of Seriatopora in the Ryukyu Archipelago will probably not recover unless there is substantial new recruitment from distant populations.

  19. Sex differences in retention after a visual or a spatial discrimination learning task in brood parasitic shiny cowbirds.

    Science.gov (United States)

    Astié, Andrea A; Scardamaglia, Romina C; Muzio, Rubén N; Reboreda, Juan C

    2015-10-01

    Females of avian brood parasites, like the shiny cowbird (Molothrus bonariensis), locate host nests and on subsequent days return to parasitize them. This ecological pressure for remembering the precise location of multiple host nests may have selected for superior spatial memory abilities. We tested the hypothesis that shiny cowbirds show sex differences in spatial memory abilities associated with sex differences in host nest searching behavior and relative hippocampus volume. We evaluated sex differences during acquisition, reversal and retention after extinction in a visual and a spatial discrimination learning task. Contrary to our prediction, females did not outperform males in the spatial task in either the acquisition or the reversal phases. Similarly, there were no sex differences in either phase in the visual task. During extinction, in both tasks the retention of females was significantly higher than expected by chance up to 50 days after the last rewarded session (∼85-90% of the trials with correct responses), but the performance of males at that time did not differ than that expected by chance. This last result shows a long-term memory capacity of female shiny cowbirds, which were able to remember information learned using either spatial or visual cues after a long retention interval. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Training "Expendable" Workers: Temporary Foreign Workers in Nursing

    Science.gov (United States)

    Taylor, Alison; Foster, Jason; Cambre, Carolina

    2012-01-01

    The purpose of this article is to explore the experiences of Temporary Foreign Workers in health care in Alberta, Canada. In 2007-2008, one of the regional health authorities in the province responded to a shortage of workers by recruiting 510 health-care workers internationally; most were trained as Registered Nurses (RNs) in the Philippines.…

  1. Stress in Humanitarian Workers

    African Journals Online (AJOL)

    user

    Stress in Humanitarian Workers: Case of the UNHCR Office in Senegal. S A Dia, A S Mohamed, M C Gaye Fall,. M Ndiaye. NB Dieng,. Department of Occupational Medicine and Forensic Medicine, Cheikh Anta Diop University at Dakar, Senegal. Corresponding author. Azhar Salim Mohamed. Dakar Fann, Sénégal, Tel: + ...

  2. Dislocated Worker Project.

    Science.gov (United States)

    1988

    Due to the severe economic decline in the automobile manufacturing industry in southeastern Michigan, a Dislocated Workers Program has been developed through the partnership of the Flint Area Chamber of Commerce, three community colleges, the National Center for Research in Vocational Education, the Michigan State Department of Education, the…

  3. Another Look at Women Workers.

    Science.gov (United States)

    Goodson, R.

    1986-01-01

    Women now comprise 30 percent of trade union membership worldwide. The International Labour Organisation's Workers' Education Branch is attempting to improve the status of women workers and increase their participation in union activities and labor education. (SK)

  4. New Dimensions of Workers' Education

    Science.gov (United States)

    Whitehouse, John R. W.

    1978-01-01

    The author suggests that labor education, by its organization through trade unions, is clearly distinguished from general adult education activities, although workers obviously participate in adult education. He discusses various ILO workers' education programs around the world. (MF)

  5. Market Structure and Worker Quality.

    OpenAIRE

    Belman, Dale; John S. Heywood

    1990-01-01

    It is frequently asserted, although never directly tested, that firms in more monopolistic industries hire better-qualified workers. This paper presents two new results. First, worker quality (education in particular) is a strong determinant of whether a worker is employed in a concentrated industry when using a traditional data source. Second, upon expanding the data to include measures of research and development, workers of better quality are actually no more likely to locate in concentrat...

  6. Effects of artificial eggs on prolactin secretion, steroid levels, brood patch development, incubation onset and clutch size in the yellow-eyed penguin (Megadyptes antipodes).

    Science.gov (United States)

    Massaro, Melanie; Setiawan, Alvin N; Davis, Lloyd S

    2007-04-01

    Several studies have shown that the transition from egg laying to incubation behavior in birds is associated with changes in plasma levels of prolactin and steroid hormones. However, any effect of the tactile and visual input provided by eggs at initiating these hormonal changes has not been fully investigated in wild birds. A few days before yellow-eyed penguins, Megadyptes antipodes, started egg laying, we placed an artificial egg into their nests or under cages next to their nest. We then investigated the effect of the tactile and/or visual stimulus of such an artificial egg on prolactin secretion, steroid hormone levels (total androgen, estradiol and progesterone), brood patch development, incubation onset and clutch size in these penguins. Prolactin levels rose in females in response to having an artificial egg in the nest, while they declined considerably in males. Total androgen concentrations in males were less than 7% of those of control males and the levels prior to egg placement. Brood patch width increased in both males and females. Additionally, an egg in the nest caused yellow-eyed penguin pairs to attend and sit prone on their nest more frequently. Females that initiated egg laying 1 or 2 days after placement of the artificial egg in the nest, laid a full clutch of two eggs, while most other females that were exposed to an artificial egg in their nest, laid only a single egg. In contrast, the visual stimulus of an artificial egg alone (that was placed under a cage) did not influence hormone levels, brood patch development, incubation behavior or clutch size. The stimulation of an egg in the nest influences prolactin and total androgen levels in yellow-eyed penguins, particularly in males. While brood patch development and incubation behavior were initiated and egg laying was terminated in response to an artificial egg in the nest, the exact endocrine mechanisms underlying these physiological and behavioral changes remain poorly understood. We

  7. 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 of ...

  8. Community Health Worker. Program Manual.

    Science.gov (United States)

    Perales, Aurora, Ed.; And Others

    Prepared to provide specific and detailed information that can be utilized by persons involved in setting up and/or already involved in the process of providing training for community health workers, the guide is divided into seven sections: (1) Philosophy and Description of Community Health Worker Role; (2) A Community Health Worker Looks at the…

  9. Older Workers. Myths and Realities.

    Science.gov (United States)

    Imel, Susan

    An increasing proportion of the work force is aging at the same time that the workplace is changing in ways that are detrimental to older workers. Attitudes and beliefs about older workers appear to be ambivalent. Studies show that employers and managers stereotype older workers as loyal and possessing good work habits but inflexible and difficult…

  10. Dermatologic Diseases in Silk Workers

    Directory of Open Access Journals (Sweden)

    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.

  11. Expression of the Prophenoloxidase Gene and Phenoloxidase Activity, During the Development of Apis Mellifera Brood Infected with Varroa Destructor

    Directory of Open Access Journals (Sweden)

    Zaobidna Ewa A.

    2015-12-01

    Full Text Available The pathogenesis of varroasis has not been fully explained despite intensive research. Earlier studies suggested that parasitic infections caused by Varroa destructor mites were accompanied by immunosuppression in the host organism. The objective of this study was to analyse the influence of varroasis on one of the immune pathway in Apis mellifera measured by the expression of the prophenoloxidase (proPO gene and the enzymatic activity of this gene’s product, phenoloxidase (EC 1.14.18.1. An evaluation was done of five developmental stages of honey bee workers and drones. The relative expression of proPO decreased in infected individuals. The only exceptions were worker prepupae (PP and drone pupae with brown eyes and dark brown thorax (P5 where propo gene expression was 1.8-fold and 1.5-fold higher, respectively, than in the control. Phenoloxidase (PO activity was 2.8-fold higher in infected pp workers and 2-fold higher in p5 drones in comparison with uninfected bees. Phenoloxidase activity was reduced in the remaining developmental stages of infected workers and drones. The relative expression of proPO was positively correlated with the relative PO activity in both workers (r = 0.988 and drones (r = 0.996. The results of the study indicate that V. destructor significantly influences the phenoloxidase-dependent immune pathway in honey bees.

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

    Directory of Open Access Journals (Sweden)

    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

  13. Immigrants and Native Workers

    DEFF Research Database (Denmark)

    Foged, Mette; Peri, Giovanni

    Using a database that includes the universe of individuals and establishments in Denmark over the period 1991-2008 we analyze the effect of a large inflow of non-European (EU) immigrants on Danish workers. We first identify a sharp and sustained supply-driven increase in the inflow of non......-EU immigrants in Denmark, beginning in 1995 and driven by a sequence of international events such as the Bosnian, Somalian and Iraqi crises. We then look at the response of occupational complexity, job upgrading and downgrading, wage and employment of natives in the short and long run. We find...... that the increased supply of non-EU low skilled immigrants pushed native workers to pursue more complex occupations. This reallocation happened mainly through movement across firms. Immigration increased mobility of natives across firms and across municipalities but it did not increase their probability...

  14. Tuberculosis in healthcare workers, Scotland.

    Science.gov (United States)

    Pollock, Kevin G; McDonald, Eisin; Smith-Palmer, Alison; Johnston, Fiona; Ahmed, Syed

    2017-08-01

    In an attempt to explore healthcare worker acquisition of tuberculosis infection, we conducted population-based surveillance of all cases recorded as healthcare workers reported to Enhanced Surveillance of Mycobacterial Infection from 2000 to 2015. Over the study period, the mean incidence rate of tuberculosis among all healthcare workers was 15.4 per 100,000 healthcare workers. However, the incidence rate of tuberculosis amongst those healthcare workers born outside the UK was 164.8 per 100,000 compared with 5.0 per 100,000 UK-born healthcare workers. Fifty-seven per cent of all non-UK-born healthcare workers were diagnosed within five years of their arrival in the UK and would have been new entrants to the NHS. An effective new entrant occupational health screening programme for latent tuberculosis infection may have prevented some of these active cases of infection.

  15. [Alcohol and construction workers].

    Science.gov (United States)

    Mosconi, G; Riva, M M; Lorenzi, S; Silva, Giulia; Bartolozzi, F; Pavesi, Greta; Bancone, Claudia; Bettineschi, O; Magno, D

    2007-01-01

    On the basis of the data drawn by national and international literature and the introduction of recent legislation concerning "alcohol and alcohol-related problems", we studied alcohol consumption and the consequences that alcohol abuse has on health, working ability, accidents and absenteeism in construction workers. We studied alcohol consumption in two groups of building workers over different periods (1996-2000; 2006). In 142 workers alcohol concentration was measured in expired air during the periodic health surveillance examination and during work on building sites. We also analyzed the relationship between declared alcohol consumption, accidents and absenteeism. Our study showed a reduction in the average consumption of alcohol over the last ten years but confirmed the role of alcohol-related diseases as a cause of work limitations or work disability. On the other hand, "breathalysing" demonstrated that alcohol consumption during pauses in work is still common. The results of this study confirm the correlation between frequency/seriousness of accidents, absenteeism and average consumption of alcohol.

  16. Honey Bee Colonies Headed by Hyperpolyandrous Queens Have Improved Brood Rearing Efficiency and Lower Infestation Rates of Parasitic Varroa Mites.

    Directory of Open Access Journals (Sweden)

    Keith S Delaplane

    Full Text Available A honey bee queen mates on wing with an average of 12 males and stores their sperm to produce progeny of mixed paternity. The degree of a queen's polyandry is positively associated with measures of her colony's fitness, and observed distributions of mating number are evolutionary optima balancing risks of mating flights against benefits to the colony. Effective mating numbers as high as 40 have been documented, begging the question of the upper bounds of this behavior that can be expected to confer colony benefit. In this study we used instrumental insemination to create three classes of queens with exaggerated range of polyandry--15, 30, or 60 drones. Colonies headed by queens inseminated with 30 or 60 drones produced more brood per bee and had a lower proportion of samples positive for Varroa destructor mites than colonies whose queens were inseminated with 15 drones, suggesting benefits of polyandry at rates higher than those normally obtaining in nature. Our results are consistent with two hypotheses that posit conditions that reward such high expressions of polyandry: (1 a queen may mate with many males in order to promote beneficial non-additive genetic interactions among subfamilies, and (2 a queen may mate with many males in order to capture a large number of rare alleles that regulate resistance to pathogens and parasites in a breeding population. Our results are unique for identifying the highest levels of polyandry yet detected that confer colony-level benefit and for showing a benefit of polyandry in particular toward the parasitic mite V. destructor.

  17. Early development of marine catfishes (Ariidae): from mouth brooding to the release of juveniles in nursery habitats.

    Science.gov (United States)

    Lima, A R A; Barletta, M; Dantas, D V; Ramos, J A A; Costa, M F

    2013-06-01

    The development and allometric growth patterns of the ariid catfishes Cathorops spixii and Cathorops agassizii were studied from neurula embryos to juveniles. The ontogenetic sequence revealed that prior to hatching, embryos of both species are well developed, and their axial and appendicular skeletons are well ossified. Embryos of both species grow slowly longitudinally, but positively allometric growth (growth coefficient, β1 > 1) was observed in head width and eye diameter. It is hypothesized that these growth patterns might be related to functional priorities for the development of sensory organs, such as the inner ears (otoliths), the Weberian apparatus, eyes and nostrils, during the embryonic period. The first appearance of vertebrae and otoliths, as well as the ossification of otoliths and the Weberian apparatus, occur earlier in embryos of C. agassizii than in embryos of C. spixii. After hatching, mouth-brooded free embryos of both species grow isometrically. Negatively allometric growth was observed in head width and eye diameter during the yolk-sac period, which is expected given that the sensory organs are already formed. Free embryos of C. agassizii are distinguishable from those of C. spixii by their larger eyes, longer snouts, longer heads and heavier yolk sacs. The end of the yolk-sac period is characterized by a direct change from free embryo to juvenile, without a true larval period. The juveniles of the two species can also be distinguished from each other by the larger eyes of C. agassizii compared with C. spixii, as in adult fishes. © 2013 The Authors. Journal of Fish Biology © 2013 The Fisheries Society of the British Isles.

  18. Kerapatan dan Kelulushidupan pada Rekrutmen Karang Pocillopora damicornis (Density and Survivorship on the Recruitment of the brooding coral Pocillopora damicornis

    Directory of Open Access Journals (Sweden)

    Munasik Munasik

    2014-09-01

    Full Text Available Studi rekrutmen karang Pocillopora damicornis telah dilakukan dengan mengamati kerapatan juvenil pada substrat penempelan di dataran terumbu Pulau Panjang, Jepara, Jawa Tengah. Hasil menunjukkan bahwa rekrutmen terjadi sepanjang tahun dan tertinggi pada periode Agustus-Oktober. Laju rekrutmen karang di belakang terumbu (back reef pada sisi bawah angin (selatan lebih tinggi daripada di sisi atas angin (utara Pulau Panjang, tampaknya hal ini berkorelasi dengan kerapatan populasi karang dewasanya. Kerapatan juvenil karang tertinggi pada substrat batu alam terjadi pada sisi bawah permukaan substrat, akan tetapi pertumbuhan juvenil karang tertinggi ditemukan di sisi atas permukaan substrat. Hal ini mengindikasikan bahwa kerapatan juvenil karang berhubungan dengan kelulusan hidup juvenil karang. Semakin tinggi kerapatan juvenil karang P. damicornis maka semakin rendah kelulusan hidup juvenil karang karena terjadinya peningkatan persaingan sesama juvenil karang dan akibat kekurangan cahaya. Kata kunci: rekrutmen, kerapatan, kelulushidupan, karang Pocillopora damicornis Recruitment of the brooding coral Pocillopora damicornis was studied by observing the juvenile density on the settlement plate substrate in reef flat of Panjang Island, Jepara, Central Java. The results show that recruitment occurs throughout the year and the highest in the period from August to October. The rate of recruitment of coral reefs in back reef on the leeward (south is higher than on the windward (north of the island, it seems to be correlated with population density of adult corals. The highest density of juvenile corals on natural substrata occurs on the lower side surface of the substrate, but the highest growth of juvenile are found on the upper side surface of the substrate. This indicates that the density of juvenile corals associated with the survival of juvenile corals. The higher density of juvenile corals P. damicornis, the lower the survival of juvenile corals due

  19. Honey Bee Colonies Headed by Hyperpolyandrous Queens Have Improved Brood Rearing Efficiency and Lower Infestation Rates of Parasitic Varroa Mites.

    Science.gov (United States)

    Delaplane, Keith S; Pietravalle, Stéphane; Brown, Mike A; Budge, Giles E

    2015-01-01

    A honey bee queen mates on wing with an average of 12 males and stores their sperm to produce progeny of mixed paternity. The degree of a queen's polyandry is positively associated with measures of her colony's fitness, and observed distributions of mating number are evolutionary optima balancing risks of mating flights against benefits to the colony. Effective mating numbers as high as 40 have been documented, begging the question of the upper bounds of this behavior that can be expected to confer colony benefit. In this study we used instrumental insemination to create three classes of queens with exaggerated range of polyandry--15, 30, or 60 drones. Colonies headed by queens inseminated with 30 or 60 drones produced more brood per bee and had a lower proportion of samples positive for Varroa destructor mites than colonies whose queens were inseminated with 15 drones, suggesting benefits of polyandry at rates higher than those normally obtaining in nature. Our results are consistent with two hypotheses that posit conditions that reward such high expressions of polyandry: (1) a queen may mate with many males in order to promote beneficial non-additive genetic interactions among subfamilies, and (2) a queen may mate with many males in order to capture a large number of rare alleles that regulate resistance to pathogens and parasites in a breeding population. Our results are unique for identifying the highest levels of polyandry yet detected that confer colony-level benefit and for showing a benefit of polyandry in particular toward the parasitic mite V. destructor.

  20. Outcomes of brood parasite-host interactions mediated by egg matching: common cuckoos Cuculus canorus versus Fringilla finches.

    Directory of Open Access Journals (Sweden)

    Johan Reinert Vikan

    Full Text Available BACKGROUND: Antagonistic species often interact via matching of phenotypes, and interactions between brood parasitic common cuckoos (Cuculus canorus and their hosts constitute classic examples. The outcome of a parasitic event is often determined by the match between host and cuckoo eggs, giving rise to potentially strong associations between fitness and egg phenotype. Yet, empirical efforts aiming to document and understand the resulting evolutionary outcomes are in short supply. METHODS/PRINCIPAL FINDINGS: We used avian color space models to analyze patterns of egg color variation within and between the cuckoo and two closely related hosts, the nomadic brambling (Fringilla montifringilla and the site fidelic chaffinch (F. coelebs. We found that there is pronounced opportunity for disruptive selection on brambling egg coloration. The corresponding cuckoo host race has evolved egg colors that maximize fitness in both sympatric and allopatric brambling populations. By contrast, the chaffinch has a more bimodal egg color distribution consistent with the evolutionary direction predicted for the brambling. Whereas the brambling and its cuckoo host race show little geographical variation in their egg color distributions, the chaffinch's distribution becomes increasingly dissimilar to the brambling's distribution towards the core area of the brambling cuckoo host race. CONCLUSION: High rates of brambling gene flow is likely to cool down coevolutionary hot spots by cancelling out the selection imposed by a patchily distributed cuckoo host race, thereby promoting a matching equilibrium. By contrast, the site fidelic chaffinch is more likely to respond to selection from adapting cuckoos, resulting in a markedly more bimodal egg color distribution. The geographic variation in the chaffinch's egg color distribution could reflect a historical gradient in parasitism pressure. Finally, marked cuckoo egg polymorphisms are unlikely to evolve in these systems

  1. 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.

  2. Value Preferences of Social Workers.

    Science.gov (United States)

    Tartakovsky, Eugene; Walsh, Sophie D

    2018-02-07

    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. © 2018 National Association of Social Workers.

  3. 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.

  4. 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.

  5. Radiological worker training

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-10-01

    This Handbook describes an implementation process for core training as recommended in Implementation Guide G441.12, Radiation Safety Training, and as outlined in the DOE Radiological Control Standard (RCS). The Handbook is meant to assist those individuals within the Department of Energy, Managing and Operating contractors, and Managing and Integrating contractors identified as having responsibility for implementing core training recommended by the RCS. This training is intended for radiological workers to assist in meeting their job-specific training requirements of 10 CFR 835. While this Handbook addresses many requirements of 10 CFR 835 Subpart J, it must be supplemented with facility-specific information to achieve full compliance.

  6. Physical activity of office workers

    OpenAIRE

    E Biernat; Tomaszewski, P.; K Milde

    2010-01-01

    Inactivity or insufficient physical activity is risk factor for metabolic or cardiovascular diseases. In most of cases the nature of work of office employees does not require high physical efforts and consists mostly of sitting but the reports on leisure activity of office workers are still lacking. Thus, the aim of the study was to assess physical activity of civil and local administration workers and bank officials. 293 randomly selected office workers took part in the study. They were recr...

  7. Career development of knowledge workers

    OpenAIRE

    2014-01-01

    M.Com. (Business Management) The knowledge economy developed out of the need for more complex products and services. The workers who are able to create such complex products and services are called knowledge workers. The term knowledge worker refers to the fact that the worker needs to be able to deal with large amounts of information, analyse and then generate knowledge out of this vast wealth of data and then be able to use this knowledge to create the necessary products and services to ...

  8. Recommended Vaccines for Healthcare Workers

    Science.gov (United States)

    ... Professionals in Infection Control and Epidemiology (APIC). Increasing Flu Vaccination Rates among Healthcare Workers Position statements from professional organizations, mandatory influenza vaccination policies, and many helpful ...

  9. Immunomodulatory effects of mineral fibres in occupationally exposed workers.

    Science.gov (United States)

    Tulinska, Jana; Jahnova, Eva; Dusinska, Maria; Kuricova, Miroslava; Liskova, Aurelia; Ilavska, Silvia; Horvathova, Mira; Wsolova, Ladislava; Kyrtopoulos, Soterios A; Collins, Andrew; Harrington, Vikki; Fuortes, Laurence

    2004-09-03

    In the context of a large-scale molecular epidemiology study, the possible immunomodulatory effects of mineral fibres, in workers occupationally exposed to asbestos, rockwool and glass fibres, were examined. In each plant, 61, 98 and 80 exposed workers and 21, 43 or 36 control clerical subjects, respectively, were recruited. In the case of the asbestos-exposed subjects, an additional town-control group of 49 people was included. Evidence of pulmonary fibrosis was found in 42% of the asbestos-exposed workers, while evidence of pleural fibrosis was found in 24%. The asbestos-exposed cohort had significantly decreased forced vital capacity of lungs as well as forced expiratory volume per first second. Our findings indicate that exposure to all three types of fibres examined modulates to different degrees the immune response. Suppression of T-cell immunity and to a lesser extent, B-cell immunity was found in the case of workers from a former asbestos cement plant, while stimulation of T-cell response was observed in rockwool workers, and stimulation of T- and B-cell response was seen in glass fibre workers. Depression of the percentage of lymphocyte subpopulation of CD 16+56 (natural killer cells) in peripheral blood was found in glass fibre workers. Statistical analysis showed increased levels of proinflammatory cytokines (IL-6 asbestos; IL-8 all three fibres), expression of adhesion molecule L-selectin on granulocytes and monocytes (asbestos), levels of soluble adhesion molecules (SAMs) in sera (ICAM-1 all three fibres; E-selectin glass fibres), increased levels of immunoglobulin E (asbestos and rockwool) and elevated expression of activation markers on eosinophils (CD66b asbestos, glass fibres; CD69 asbestos). Significant correlations were observed between lymphocyte proliferation and markers of DNA damage and repair. Increased levels of proinflammatory cytokines, SAMs, immunoglobulin E and elevated expression of activation markers on eosinophils was found in people

  10. Effect of Brood Age on Nestling Diet and Prey Composition in a Hedgerow Specialist Bird, the Barred Warbler Sylvia nisoria.

    Science.gov (United States)

    Orłowski, Grzegorz; Wuczyński, Andrzej; Karg, Jerzy

    2015-01-01

    The composition and quality of food provided to nestling birds influence their growth and development and offers key insight into the ecological requirements of birds. One bird species whose feeding ecology is poorly understood is the Barred Warbler (Sylvia nisoria), which utilizes semi-natural shrubby vegetation in agroecosystems. Because Barred Warbler nestlings vary greatly in body mass we hypothesised that diet and prey properties (size, diversity, taxonomic composition, and chitin content and resulting body hardness and digestibility) would differ as the nestlings aged. We quantified the diet based on faecal analysis, sampling faecal sacs from the nestlings pooled into three age classes: 2-3 days old, 4-6 d old, and 7-9 d old. Nestlings were provided a wide diversity of food and a strong relationship existed between food characteristics and nestling age. The youngest nestlings (2-3 d old) had the lowest values of each dietary characteristic (diversity, number and total biomass of prey, and individual prey weight), that were significantly lower than the oldest nestlings (7-9 d old). Nestlings aged 4-6 d exhibited intermediate dietary characteristics. Differences in dietary composition of the six major food types showed marked differences between the individual broods and age categories. Percentages of the number and biomass of soft-bodied prey were highest in the diet of 2-3 d and 4-6 d old nestlings, and decreased with increasing age, whereas the opposite trend was observed in the percentage of intermediately and heavily chitinised prey. Parent Barred Warblers probably preferentially select soft-bodied prey for the youngest nestlings, and satisfy the greater energy demands of the older ones by providing them with a greater variety of prey containing more chitin, as well as plant food. The provisioning of less-readily digestible prey to older nestlings suggests that as the quality of food decreases the quantity increases, implying that the youngest nestlings

  11. Effect of Brood Age on Nestling Diet and Prey Composition in a Hedgerow Specialist Bird, the Barred Warbler Sylvia nisoria.

    Directory of Open Access Journals (Sweden)

    Grzegorz Orłowski

    Full Text Available The composition and quality of food provided to nestling birds influence their growth and development and offers key insight into the ecological requirements of birds. One bird species whose feeding ecology is poorly understood is the Barred Warbler (Sylvia nisoria, which utilizes semi-natural shrubby vegetation in agroecosystems. Because Barred Warbler nestlings vary greatly in body mass we hypothesised that diet and prey properties (size, diversity, taxonomic composition, and chitin content and resulting body hardness and digestibility would differ as the nestlings aged. We quantified the diet based on faecal analysis, sampling faecal sacs from the nestlings pooled into three age classes: 2-3 days old, 4-6 d old, and 7-9 d old. Nestlings were provided a wide diversity of food and a strong relationship existed between food characteristics and nestling age. The youngest nestlings (2-3 d old had the lowest values of each dietary characteristic (diversity, number and total biomass of prey, and individual prey weight, that were significantly lower than the oldest nestlings (7-9 d old. Nestlings aged 4-6 d exhibited intermediate dietary characteristics. Differences in dietary composition of the six major food types showed marked differences between the individual broods and age categories. Percentages of the number and biomass of soft-bodied prey were highest in the diet of 2-3 d and 4-6 d old nestlings, and decreased with increasing age, whereas the opposite trend was observed in the percentage of intermediately and heavily chitinised prey. Parent Barred Warblers probably preferentially select soft-bodied prey for the youngest nestlings, and satisfy the greater energy demands of the older ones by providing them with a greater variety of prey containing more chitin, as well as plant food. The provisioning of less-readily digestible prey to older nestlings suggests that as the quality of food decreases the quantity increases, implying that the

  12. Effect of Brood Age on Nestling Diet and Prey Composition in a Hedgerow Specialist Bird, the Barred Warbler Sylvia nisoria

    Science.gov (United States)

    Orłowski, Grzegorz; Wuczyński, Andrzej; Karg, Jerzy

    2015-01-01

    The composition and quality of food provided to nestling birds influence their growth and development and offers key insight into the ecological requirements of birds. One bird species whose feeding ecology is poorly understood is the Barred Warbler (Sylvia nisoria), which utilizes semi-natural shrubby vegetation in agroecosystems. Because Barred Warbler nestlings vary greatly in body mass we hypothesised that diet and prey properties (size, diversity, taxonomic composition, and chitin content and resulting body hardness and digestibility) would differ as the nestlings aged. We quantified the diet based on faecal analysis, sampling faecal sacs from the nestlings pooled into three age classes: 2-3 days old, 4-6 d old, and 7-9 d old. Nestlings were provided a wide diversity of food and a strong relationship existed between food characteristics and nestling age. The youngest nestlings (2-3 d old) had the lowest values of each dietary characteristic (diversity, number and total biomass of prey, and individual prey weight), that were significantly lower than the oldest nestlings (7-9 d old). Nestlings aged 4-6 d exhibited intermediate dietary characteristics. Differences in dietary composition of the six major food types showed marked differences between the individual broods and age categories. Percentages of the number and biomass of soft-bodied prey were highest in the diet of 2-3 d and 4-6 d old nestlings, and decreased with increasing age, whereas the opposite trend was observed in the percentage of intermediately and heavily chitinised prey. Parent Barred Warblers probably preferentially select soft-bodied prey for the youngest nestlings, and satisfy the greater energy demands of the older ones by providing them with a greater variety of prey containing more chitin, as well as plant food. The provisioning of less-readily digestible prey to older nestlings suggests that as the quality of food decreases the quantity increases, implying that the youngest nestlings

  13. ADVANCED WORKER PROTECTION SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Judson Hedgehock

    2001-03-16

    From 1993 to 2000, OSS worked under a cost share contract from the Department of Energy (DOE) to develop an Advanced Worker Protection System (AWPS). The AWPS is a protective ensemble that provides the user with both breathing air and cooling for a NIOSH-rated duration of two hours. The ensemble consists of a liquid air based backpack, a Liquid Cooling Garment (LCG), and an outer protective garment. The AWPS project was divided into two phases. During Phase 1, OSS developed and tested a full-scale prototype AWPS. The testing showed that workers using the AWPS could work twice as long as workers using a standard SCBA. The testing also provided performance data on the AWPS in different environments that was used during Phase 2 to optimize the design. During Phase 1, OSS also performed a life-cycle cost analysis on a representative clean up effort. The analysis indicated that the AWPS could save the DOE millions of dollars on D and D activities and improve the health and safety of their workers. During Phase 2, OSS worked to optimize the AWPS design to increase system reliability, to improve system performance and comfort, and to reduce the backpack weight and manufacturing costs. To support this design effort, OSS developed and tested several different generations of prototype units. Two separate successful evaluations of the ensemble were performed by the International Union of Operation Engineers (IUOE). The results of these evaluations were used to drive the design. During Phase 2, OSS also pursued certifying the AWPS with the applicable government agencies. The initial intent during Phase 2 was to finalize the design and then to certify the system. OSS and Scott Health and Safety Products teamed to optimize the AWPS design and then certify the system with the National Institute of Occupational Health and Safety (NIOSH). Unfortunately, technical and programmatic difficulties prevented us from obtaining NIOSH certification. Despite the inability of NIOSH to certify

  14. 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.

  15. 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,

  16. A Comparison of Workers Employed in Hazardous Jobs in Terms of Job Satisfaction, Perceived Job Risk and Stress: Turkish Jean Sandblasting Workers, Dock Workers, Factory Workers and Miners

    Science.gov (United States)

    Sunal, Ayda Buyuksahin; Sunal, Onur; Yasin, Fatma

    2011-01-01

    The purpose of this study is to compare job satisfaction, perception of job risk, stress symptoms and vulnerability to stress of miners, dock workers, jean sandblasting workers and factory workers. A job satisfaction scale and stress audit scale were applied to 220 workers. Results revealed that dock and jean sandblasting workers perceived their…

  17. Development of functional foods for radiation workers - In vivo test on the effect of functional food for stem cell protection and preparing the provisional product

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Ho; Oh, Heon; Kim, Se Ra; Lee, Song Eun [Chonnam National University, Kwangju (Korea)

    2000-04-01

    We performed this study to determine (1) the effect of several oriental prescriptions as energy tonic (Chinese medical concept : Bu-Qi) or blood building (Chinese medical concept : Bu-Xie) decoction and its major ingredients, (2) the biological stability of irradiated Chinese medical prescriptions, and (3) the effect of several proposed prescriptions and its fractions on jejunal crypt survival (12 Gy), endogenous spleen colony formation(6.5 Gy), and apoptosis(2 Gy) in jejunal crypt cells of mice irradiated with high and low dose of gamma-irradiation. For the study of evaluation on the radioprotective effects of effective prescriptions, we tried the test on change of survival and hematological changes and finally we prepared the provisional product. 57 refs., 5 figs., 38 tabs. (Author)

  18. Predicting amphipods' brood size variation in brackish environments: an empirical model for Corophium multisetosum Stock, 1952 (Corophiidae) in Ria de Aveiro (NW Portugal).

    Science.gov (United States)

    Cunha; Moreira; Sorbe

    2000-05-31

    Data on fecundity of Corophium multisetosum from Areão (Ria de Aveiro, Portugal) are analysed by non linear regression to quantify the relationship between brood size (N(e)) and head length (L(h), in mm), water temperature (T, in degrees Celsius) and salinity (S, in psu). The aim of the analysis is to obtain a simple line N(e)=a+bL(h), in which the slope (b) and the y intercept (a) are functions of salinity and/or temperature on each sampling occasion. The equation N(e)=(-2.940-8.027S)+(-89.431+18.171S+12.904T-0.368T(2))L(h) explains 64% of the variability of brood size throughout the breeding period. The model predicts an optimal temperature around 18 degrees C and a very low fecundity at low salinities. The graphical comparison of the lines obtained by the model and by a usual linear regression illustrates its potential usefulness to predict fecundity changes. The authors suggest that the observed variation in the fecundity of other brackish-water amphipods can be described and predicted using similar models.

  19. 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

  20. Economic Globalization and Workers: introduction

    NARCIS (Netherlands)

    E-J. Visser (Evert-Jan); M.P. van Dijk (Meine Pieter)

    2006-01-01

    textabstractThis dossier deals with the impact of economic globalisation on workers, especially in developing nations: their employment opportunities, wage income, job security and other aspects of decent work (ILO 1999, 2002). This is a highly relevant theme. Not only do workers in the EU, the

  1. EXTENSION WORKERS' OPINIONS REGARDING THE ...

    African Journals Online (AJOL)

    The primary purpose of the study was to determine extension worker's opinions regarding the influence of the National Maize Competition (NAMCOM) on the farmers' agricultural practices and experiences in the Manzini region. A census population of front-line extension workers in charge of the participating areas in ...

  2. [PAH exposure in asphalt workers].

    Science.gov (United States)

    Garattini, Siria; Sarnico, Michela; Benvenuti, Alessandra; Barbieri, P G

    2010-01-01

    There has been interest in evaluating the potential carcinogenicity of bitumen fumes in asphalt workers since the 1960's. The IARC classified air-refined bitumens as possible human carcinogens, while coal-tar fumes were classified as known carcinogens. Occupational/environmental PAH exposure can be measured by several urinary markers. Urinary 1-OHP has become the most commonly used biological marker of PAH exposure in asphalt workers. The aim of this study was to assess asphalt workers' exposure levels by monitoring 1-OHP urinary excretion and compare this data with those of non-occupationally exposed subjects. We investigated three groups of asphalt workers: 100 in summer 2007, 29 in winter 2007, and 148 during summer 2008 and compared 1-OHP urinary concentrations using Kruskall-Wallis test. Median 1-OHP urinary concentrations during the three biomonitoring sampling periods were 0.65, 0.17 and 0.53 microg/g creatinine respectively. There was a significant difference in 1-OHP values between the three groups (p < 0.001). our study showed that PAH exposure of asphalt workers' is higher than that observed in the general population and in workers in urban areas. Our results suggest that PAH exposure in the three groups studied is not sufficiently kept under control by the use of personal protective equipment and that biomonitoring is useful in evaluating PAH exposure and for risk assessment. Regulations need to be enforced for workers exposed to cancer risk, such as the register of workers exposed to carcinogens.

  3. Technological Change: Helping Workers Adjust.

    Science.gov (United States)

    Mowery, David C.

    1987-01-01

    Discusses some of the problems in employment shifts and unemployment caused by new technologies in offices and factories. Addresses the Job Training Partnership Act (Title III) which was established as the primary assistance vehicle for displaced workers. Calls for workers to receive sufficient time to adjust to technologies. (TW)

  4. Retraining Displaced Workers. Policy Brief

    Science.gov (United States)

    LaLonde, Robert; Sullivan, Daniel

    2010-01-01

    Robert LaLonde of the University of Chicago and Daniel Sullivan of the Federal Reserve Bank of Chicago suggest that retraining through our nation's community colleges is a way to reduce the skills gaps of at least some of these displaced workers and increase their reemployment earnings. Although workers may still experience significant earnings…

  5. National Association of Social Workers

    Science.gov (United States)

    ... Social Worker Shortage In hardest hit states, more social workers needed in child welfare and addiction treatment. Join NASW today! What's New NASW Condemns President Trump's DACA Decision Decision to rescind Deferred Action ... the American Culture This Social Justice Brief examines gun violence in a public ...

  6. Immunologic findings in confectionary workers.

    Science.gov (United States)

    Zuskin, E; Kanceljak, B; Mustajbegovic, J; Schachter, E N

    1994-12-01

    Food allergies are frequent in the general population. There are however, few studies of immunologic responses among workers in the confectionary industry. To assess immunologic and clinical findings of workers in a confectionary plant. Immunologic (skin tests and serum IgE) and respiratory findings (symptoms and lung function) were studied in a group of 71 confectionary workers (mean age: 35 years and mean exposure: 11 years). Skin prick testing with food extracts used in the manufacturing of candies and pastries demonstrated that the most frequent positive skin reaction occurred with extracts of cacao (31%), followed by reactions to chocolate (9%), cocoa (6%), hazelnut (6%), and sugar (2%). Increased serum IgE levels were found in 13.0% and increased IgM serum levels in 52.1% of these confectionary workers. The prevalence of asthma (26.1%) and dyspnea (26.1%) in workers with positive skin tests was significantly higher than in workers with negative skin tests (asthma: 2.0%, P = .004; dyspnea: 4.1%, P = .001). There was a high prevalence of acute respiratory symptoms during the work shift, but no significant association with immunologic tests was found. Similarly, both skin test positive and skin test negative workers exhibited significant across shift changes in lung function; however, no significant differences in baseline lung function or across-shift changes were noted between skin test positive and negative workers. Pre-shift administration of disodium cromoglycate (DSCG) significantly diminished across-shift reductions in FEF50 and FEF25 for both skin test positive and skin test negative workers. These data suggest that exposure to environmental factors in confectionary plants is associated with frequent respiratory symptoms of an irritative nature. Specific skin testing may be useful in characterizing confectionary workers at risk for the development of occupational asthma.

  7. Why a Domestic Workers Bill of Rights?

    OpenAIRE

    Appelbaum, Lauren D

    2010-01-01

    In August 2010, the California State Legislature passed a Resolution for a Domestic Workers Bill of Rights. This resolution highlights the work done by domestic workers in the state and the labor violations faced by these workers. The resolution calls for the fair treatment of these workers, noting that domestic workers have a right to be treated with respect and dignity. On November 29, 2010, New York State enacted a new Domestic Workers Bill of Rights, which guarantees basic work standards ...

  8. Asthma characteristics in cleaning workers, workers in other risk jobs and office workers

    NARCIS (Netherlands)

    Zock, JP; Kogevinas, M; Sunyer, J; Jarvis, D; Toren, K; Anto, JM

    Several studies have demonstrated an excess risk for asthma among cleaning workers. The aim of this analysis was to compare clinical, immunological and functional characteristics associated with asthma in cleaners and other occupational groups. Cleaners, workers exposed to high molecular weight (MW)

  9. 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

  10. Cancer mortality and morbidity among rubber workers.

    Science.gov (United States)

    Monson, R R; Fine, L J

    1978-10-01

    Mortality and morbidity from cancer among a cohort of 13,570 white male rubber workers were examined. Each man worked for at least 5 years at the Akron, Ohio, plant of the B. F. Goodrich Company. The potential period of follow-up was from January 1, 1940 to June 30, 1976. Departmental work histories were based primarily on records maintained by Local no. 5, United Rubber Workers. The occurrence of cancer was measured by death certificates and by a survey of Akron-area hospital tumor registries from 1964 to 1974. Two types of analyses were made: 1) an external comparison of mortality rates of rubber workers versus rates of U.S. white males, and 2) an internal comparison of cancer morbidity rates among persons who were employed in various work areas of the plant. Excess cases of specific cancers (observed/expected numbers) among workers in specific work areas included: stomach and intestine: rubber making (30/14.4); lung: tire curing (31/14.1), fuel cells and/or deicers (46/29.1); bladder: chemical plant (6/2.4), and tire building (16/10.7); skin cancer: tire assembly (12/1.9); brain cancer: tire assembly (8/2.0); lymphatic cancer: tire building (8/3.2); and leukemia: calendering (8/2.2), tire curing (8/2.6), tire building (12/7.5), elevators (4/1.4), tubes (4/1.6), and rubber fabrics (4/1.1). Agents that may be responsible for these excesses were considered.

  11. Informal economy and migrant worker.

    Directory of Open Access Journals (Sweden)

    Concha Carrasco Carpio

    2016-10-01

    Full Text Available The present article is based on the analysis of the information obtained by an empirical estimation conducted among 1103 non-European immigrants, representative of the fifteen more relevant nationalities in Spain. The main target of this research has been to analyze the situation of the immigrant worker in the informal sector of the Spanish labour market. This informal sector has not been created by the immigrant workers. The irregular immigrant worker can not achieve legal job contracts; this situation does not exclude them from the labour market, but it limits their participation in the informal sector.

  12. Interphase cytogenetics of workers exposed to benzene

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, L.; Wang, Yunxia; Venkatesh, P. [Univ. of California, Berkeley, CA (United States)] [and others

    1996-12-01

    Fluorescence in situ hybridization (FISH) is a powerful new technique that allows numerical chromosome aberrations (aneuploidy) to be detected in interphase cells. In previous studies, FISH has been used to demonstrate that the benzene metabolites hydroquinone and 1,2,4-benzenetriol induce aneuploidy of chromosomes 7 and 9 in cultures of human cells. In the present study, we used an interphase FISH procedure to perform cytogenetic analyses on the blood cells of 43 workers exposed to benzene (median=31 ppm, 8-hr time-weighted average) and 44 matched controls from Shanghai, China. High benzene exposure (>31 ppm, n=22) increased the hyperdiploid frequency of chromosome 9 (p<0.01), but lower exposure (<31 ppm, n=21) did not. Trisomy 9 was the major form of benzene-induced hyperdiploidy. The level of hyperdiploidy in exposed workers correlated with their urinary phenol level (r= 0.58, p < 0.0001), a measure of internal benzene close. A significant correlation was also found between hyperdiploicly and decreased absolute lymphocyte count, an indicator of benzene hematotoxicity, in the exposed group (r=-0.44, p=0.003) but not in controls (r=-0.09, P=0.58). These results show that high benzene exposure induces aneuploidy of chromosome 9 in nondiseased individuals, with trisomy being the most prevalent form. They further highlight the usefulness of interphase cytogenetics and FISH for the rapid and sensitive detection of aneuploidy in exposed human populations. 35 refs., 3 figs., 2 tabs.

  13. Convergence of carbohydrate-biased intake targets in caged worker honeybees fed different protein sources.

    Science.gov (United States)

    Altaye, Solomon Z; Pirk, Christian W W; Crewe, Robin M; Nicolson, Susan W

    2010-10-01

    The nutritional needs of bees are supplied by nectar carbohydrates and by protein and other nutrients in pollen but little is known of how bees achieve nutritional balance. Using newly emerged caged worker honeybees (Apis mellifera scutellata), we investigated whether bees maintain their intake target when confined to pairs of imbalanced complementary diets varying in protein to carbohydrate (P:C) ratio. Diets were formulated using three protein sources [casein, royal jelly or Feed-Bee (a natural pollen substitute)] and sucrose. Within each protein type, honeybees switched between complementary diets and converged on the same P:C intake target. However, this target differed between protein types: P:C ratios were 1:12, 1:14 and 1:11 on casein, royal jelly and Feed-Bee diets, respectively. Except for an early peak in protein consumption on royal jelly diets, these strongly convergent ratios remained constant over the 14 day experiment. This is probably due to the absence of brood, reflected in relatively stable values measured for haemolymph protein concentration and hypopharyngeal gland activation in bees on Feed-Bee diets. Performance of caged workers was also assessed in terms of survival and ovarian activation. Survival was highest on casein diets and lowest on Feed-Bee diets but ovarian activation was highest on royal jelly diets and lowest on casein diets. This may be due to additional components in Feed-Bee and royal jelly (e.g. fatty acids), which are needed to activate the ovaries but also reduce survival. Nutrient intake of broodless workers is directly related to their own physiological requirements, and the strong carbohydrate bias may reflect the high metabolic rate of honeybees even under resting conditions.

  14. Interviewing media workers

    Directory of Open Access Journals (Sweden)

    Heike Graf

    2010-11-01

    Full Text Available The focus of this article is on the use of Niklas Luhmann’s systems theoretical approach in order to analyse interviews conducted with media workers concerning their experiences of ethnic diversity in newsrooms. Applying systems theory means constructing the interview as a social system and seeing the “data” as observations produced by the observer and not as representations of a reality. The first part of the article describes the interview methodology and the second part provides examples, from the current study, of how systems theory can be applied in order to analyse interviews. Using a difference-theoretical approach means looking at the distinctions the informants make when talking about their experiences. These main guiding distinctions can be summarised as immigrant background/competence as well as advantage/competence. Using the guiding distinction of inclusion/exclusion when interpreting the interviewees’ statements, the interdependencies of mechanisms of inclusion and exclusion in newsrooms related to ethnic background can be examined.

  15. The worker profile autocontrolled

    Directory of Open Access Journals (Sweden)

    Jairo Omar Delgado Mora

    2015-06-01

    Full Text Available This document is part of two deliveries. In this first paper is to make an approach to the concept of self-control from the very beginning with Sakichi Toyoda, founder of what the industry Toyota Motor Company, additionally taking some excerpts of the concept issued by teachers and the psychologist Henry Murray, a professor at the university Harvard precursor test TAT personality test creator, pen applied world wide by psychologists David McCllelan, also a psychologist and a pioneer in the study of human needs and the concept of competence; Professor Jeffrey Pfeffer of Stanford University organizational behavior and theory, Frederick Hertzberg, Psychologist and strong influential in business management, Kronfly Cruz, lawyer and investigator of social and administrative sciences, Charles Perrow, a sociologist at Yale University and Stanford , who studies the impact of large organizations in society, among others. The study reflects the need to meet organizational objectives related to the physicochemical characteristics of the finished product in a plant of the company’s main beers in the country. In this paper, we intend to make an approximation of worker self -controlled, which when compared with the powers, generic, specific and technical area established by the brewery, will allow generating a methodology to adjust these competencies and to obtain the target profile drawn. This comparison and development of the methodology proposed is the subject of the second work planned.

  16. 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...

  17. Facts about Hospital Worker Safety

    Science.gov (United States)

    ... and Worker Safety: Opportunities for Synergy, Collaboration, and Innovation . 5 Bureau of Labor Statistics. Case and Demographic ... Shea, and M. Martinez. 2009. The lift team’s importance to a successful safe patient handling program. Journal ...

  18. NGO field workers in Pakistan

    Directory of Open Access Journals (Sweden)

    Muhammad Haroon SIDDIQUE

    2009-06-01

    Full Text Available NGOs came into the society in their present form after World War II and more precisely in 1960s. Before that also different forms of philanthropy existed. Like elsewhere in the world, in Pakistan also state and the market were the two sectors catering for different needs of the people. When foreign funding started coming into the poor countries, the channel of NGOs was considered more appropriate including the fact they had roots in the society and the benefit could reach the far flung areas. NGO field workers are the real actors in the NGOs’ activities but sadly the NGOs those raise the slogans of working for the destitute do not bother to facilitate the NGO field workers. Eventually the NGO field workers are facing problems of job insecurity, poor salary structure, unhealthy working environment and even harassment especially in case of women NGO field workers in Pakistan

  19. Silicosis in silica flour workers.

    Science.gov (United States)

    Banks, D E; Morring, K L; Boehlecke, B A; Althouse, R B; Merchant, J A

    1981-10-01

    In July 1979, the health of 86 current and ex-workers at 2 silica mining and milling operations in southern Illinois was examined using a respiratory questionnaire, spirometry, and chest radiographs. None of 25 current workers with less than 1 yr of exposure to silica dust had radiographic evidence of silicosis. For 61 current workers and ex-workers with 1 or more yr of exposure, chest radiographs showed 16 (26%) with simple silicosis and 7 (11%) with progressive massive fibrosis. Of these 23, 8 with simple silicosis and 3 with progressive massive fibrosis began work after the first Mine Safety and Health Administration inspection in 1973. These data and a review of federal dust inspection results between 1973 and 1979 showed that these cases of silicosis could have been prevented by effecting compliance with the existing dust standard.

  20. Contingent Faculty as Nonideal Workers

    Science.gov (United States)

    Kezar, Adrianna; Bernstein-Sierra, Samantha

    2016-01-01

    This chapter explores how contingent faculty address the issue of work and family and demonstrates the importance of understanding the diversity of contingent faculty experiences and of underemployment rather than notions of the ideal worker to explain their work lives.

  1. Workers' Control in Three Countries

    Science.gov (United States)

    Hayes, Edward

    1976-01-01

    Describes a video tape which examines the kinds of worker participation in management schemes that exist in the United States, Sweden, and Yugoslavia. Can be ordered from: Edward Hayes, Department of Government, Ohio University, Athens, Ohio 45701. (Author/DB)

  2. Workers' compensation and hepatitis C

    National Research Council Canada - National Science Library

    Sfikas, P M

    2000-01-01

    Dentists may be required to pay workers' compensation benefits for an employee with hepatitis C even if the employee was not working at the dentist's office at the time he or she contracted the disease...

  3. Outplacement for Underserved Women Workers.

    Science.gov (United States)

    Freeman, Suzanne C.; Haring-Hidore, Marilyn

    1988-01-01

    Describes an outplacement program for hourly women workers that assisted participants in identifying skills, interests, and values; identified community resources; taught job hunting skills; and encouraged participation in a support group. (JOW)

  4. Goal setting and worker motivation

    OpenAIRE

    Goerg, Sebastian J.

    2015-01-01

    Employers want motivated and productive employees. Are there ways to increase employee motivation without relying solely on monetary incentives, such as pay-for-performance schemes? One tool that has shown promise in recent decades for improving worker performance is setting goals, whether they are assigned by management or self-chosen. Goals are powerful motivators for workers, with the potential for boosting productivity in an organization. However, if not chosen carefully or if used in uns...

  5. "Cloud" health-care workers.

    OpenAIRE

    Sherertz, R J; Bassetti, S.; Bassetti-Wyss, B.

    2001-01-01

    Certain bacteria dispersed by health-care workers can cause hospital infections. Asymptomatic health-care workers colonized rectally, vaginally, or on the skin with group A streptococci have caused outbreaks of surgical site infection by airborne dispersal. Outbreaks have been associated with skin colonization or viral upper respiratory tract infection in a phenomenon of airborne dispersal of Staphylococcus aureus called the "cloud" phenomenon. This review summarizes the data supporting the e...

  6. Active Strategies for Older Workers

    DEFF Research Database (Denmark)

    Hansen, Hans

    This report is also to be published by ETUI (Euruopean Trade Unions' Institute) in a book on Active Strategies for Older Workers. It is the National report for Denmark and contains a short section on characteristics of the Danish labour market, with a special focus on the situation of the elderly...... the older workers in the labour force. A third section will focus on the initiatives taken to promote senior policies also from the government....

  7. Functional flexibility of the honey bee hypopharyngeal gland in a dequeened colony.

    Science.gov (United States)

    Ohashi, K; Sasaki, M; Sasagawa, H; Nakamura, J; Natori, S; Kubo, T

    2000-11-01

    The role of the worker honey bee Apis mellifera L. changes depending on age after eclosion (age polyethism): young workers (nurse bees) take care of their brood by synthesizing and secreting brood food (royal jelly), while older workers (foragers) forage for nectar and process it into honey. Previously, we showed that the major proteins synthesized in the hypopharyngeal gland of the worker change from brood food proteins to alpha-glucosidase at the single secretory cell level in parallel with this age polyethism [Kubo et al., J. Biochem. 119, 291-295 (1996); Ohashi et al., Eur. J. Biochem. 249, 797-802 (1997)]. Here, we examined whether the function of the hypopharyngeal gland has flexibility depending on the colony conditions, by creating a dequeened colony in which the older workers were compelled to feed the drone larvae. It was found that most of the older workers in the dequeened colony synthesized brood food proteins as did nurse bees. Furthermore, the percentage of workers that synthesized brood food proteins was maintained at 80-90% of the total workers for at least two months, as in a normal colony. These results indicate that the function of the hypopharyngeal gland cells of the worker has flexibility and can, if necessary, be maintained as that of the nurse bee, depending on the condition of the colony.

  8. Peltogasterella sensuru n. sp. (Crustacea: Cirripedia: Rhizocephala) from off Okinawa Island (Ryukyu Archipelago, Japan) with remarks on its single brood externae.

    Science.gov (United States)

    Yoshida, Ryuta; Hirose, Mamiko; Hirose, Euichi

    2015-09-01

    Peltogasterella sensuru n. sp. infests Pagurixus hermit crabs inhabiting rocky shores off Okinawa Island (Ryukyu Archipelago, Japan). This species is clearly distinguishable from Peltogasterella gracilis (Boschma, 1927): the stalk emerges from the middle part of the externa in the present species and P. sulcata (Lilljeborg, 1859), while the stalk in P. gracilis emerges from the posterior end of the externae. The new species differs from P. sulcata based on the morphology of the mantle aperture. Peltogasterella sensuru n. sp. repeatedly produces single brood externae that have not been previously observed in species belonging to the suborder Kentrogonida Delage, 1884. We also determined partial sequences of the COI gene and 16S rRNA gene of the new species for use as molecular markers for species identification.

  9. Growth patterns in brooding dinosaurs reveals the timing of sexual maturity in non-avian dinosaurs and genesis of the avian condition.

    Science.gov (United States)

    Erickson, Gregory M; Curry Rogers, Kristina; Varricchio, David J; Norell, Mark A; Xu, Xing

    2007-10-22

    The timing of sexual maturation in non-avian dinosaurs is not known. In extant squamates and crocodilians it occurs in conjunction with the initial slowing of growth rates as adult size is approached. In birds (living dinosaurs) on the other hand, reproductive activity begins well after somatic maturity. Here we used growth line counts and spacing in all of the known brooding non-avian dinosaurs to determine the stages of development when they perished. It was revealed that sexual maturation occurred well before full adult size was reached-the primitive reptilian condition. In this sense, the life history and physiology of non-avian dinosaurs was not like that of modern birds. Palaeobiological ramifications of these findings include the potential to deduce reproductive lifespan, fecundity and reproductive population sizes in non-avian dinosaurs, as well as aid in the identification of secondary sexual characteristics.

  10. 29 CFR 779.409 - Handicapped workers.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Handicapped workers. 779.409 Section 779.409 Labor... Students, Learners, and Handicapped Workers § 779.409 Handicapped workers. Regulations have been issued... handicapped workers at wages lower than the minimum wage applicable under section 6 of the Act. These...

  11. 29 CFR 525.4 - Patient workers.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Patient workers. 525.4 Section 525.4 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR DIVISION, DEPARTMENT OF LABOR REGULATIONS EMPLOYMENT OF WORKERS WITH DISABILITIES UNDER SPECIAL CERTIFICATES § 525.4 Patient workers. With respect to patient workers...

  12. The Older Worker. Myths and Realities.

    Science.gov (United States)

    Stein, David; Rocco, Tonette S.

    Although workplaces are searching for ways to increase productivity, older workers asking for increased career development opportunities are neglected by most workplaces. Age alone may not be a defining characteristic of an older worker. Perhaps becoming an older worker is more situational than chronological. Retirement for future older workers is…

  13. The impact of climate and cyclic food abundance on the timing of breeding and brood size in four boreal owl species.

    Science.gov (United States)

    Lehikoinen, Aleksi; Ranta, Esa; Pietiäinen, Hannu; Byholm, Patrik; Saurola, Pertti; Valkama, Jari; Huitu, Otso; Henttonen, Heikki; Korpimäki, Erkki

    2011-02-01

    The ongoing climate change has improved our understanding of how climate affects the reproduction of animals. However, the interaction between food availability and climate on breeding has rarely been examined. While it has been shown that breeding of boreal birds of prey is first and foremost determined by prey abundance, little information exists on how climatic conditions influence this relationship. We studied the joint effects of main prey abundance and ambient weather on timing of breeding and reproductive success of two smaller (pygmy owl Glaucidium passerinum and Tengmalm's owl Aegolius funereus) and two larger (tawny owl Strix aluco and Ural owl Strix uralensis) avian predator species using long-term nation-wide datasets during 1973-2004. We found no temporal trend either in vole abundance or in hatching date and brood size of any studied owl species. In the larger species, increasing late winter or early spring temperature advanced breeding at least as much as did high autumn abundance of prey (voles). Furthermore, increasing snow depth delayed breeding of the largest species (Ural owl), presumably by reducing the availability of voles. Brood size was strongly determined by spring vole abundance in all four owl species. These results show that climate directly affects the breeding performance of vole-eating boreal avian predators much more than previously thought. According to earlier studies, small-sized species should advance their breeding more than larger species in response to increasing temperature. However, we found an opposite pattern, with larger species being more sensitive to temperature. We argue that this pattern is caused by a difference in the breeding tactics of larger mostly capital breeding and smaller mostly income breeding owl species.

  14. 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.

  15. Evaluation of 1991-1992 Brood Overwinter-Reared Coho Released from Net Pens in Youngs Bay, Oregon : Final Completion Report Youngs Bay Terminal Fishery Project.

    Energy Technology Data Exchange (ETDEWEB)

    Hirose, Paul 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.

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

    Science.gov (United States)

    Fernández-Juricic, Esteban; Ojeda, Agustin; Deisher, Marcella; Burry, Brianna; Baumhardt, Patrice; Stark, Amy; Elmore, Amanda G; Ensminger, Amanda L

    2013-01-01

    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. 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. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  18. 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.

  19. Quality of Life Satisfaction among Workers and Non-Workers in Uruguay

    Science.gov (United States)

    Gandelman, Nestor; Piani, Giorgina

    2013-01-01

    In this paper we use data from a population survey on quality of life dimensions conducted in Uruguay to analyze the self reported well-being among workers and non workers. Along with the literature, we find that the probability of being happy is greater for workers than non-workers. Specifically, we find evidence that workers tend to be more…

  20. Survey on low-dose medical radiation exposure in occupational workers: the effect on hematological change

    Science.gov (United States)

    Ryu, J. K.; Cho, S. M.; Cho, J. H.; Dong, K. R.; Chung, W. K.; Lee, J. W.

    2013-03-01

    This study examined the changes in the hematological index caused by low-dose medical radiation exposure in workers in a medical radiation-exposed environment. The cumulative dose was obtained using thermoluminescent dosimeters over a 9-year period, and the changes in hematological index count (red blood cells (RBCs), hemoglobin, platelets, white blood cells (WBCs), monocytes, lymphocytes, neutrophils, basophils, and eosinophils) were examined in both the occupational workers and controls. In total, 370 occupational workers and 335 controls were compared. The analysis led to the following observations: (1) The average cumulative dose in males and females was 9.65±15.2 and 4.82±5.55 mSv, respectively. (2) In both males and females, there was a very low correlation between the occupation period and the cumulative dose (r<±0.25). (3) When the occupation period was longer, the WBC counts both decreased and increased in the male workers and the RBC counts were lower in the workers than in the control group (p<0.05). In females, the WBC counts both decreased and increased in the workers and the eosinophil counts were lower in the workers than in the control group (p<0.01). (4) When the cumulative dose was large, the lymphocyte counts decreased in male workers and the platelet count was lower in the workers than in the control group (p<0.05). In females, the lymphocyte count and RBC count were lower in the workers than in the control group (p<0.05). Abnormal distributions of some blood indices were observed in the occupational radiation workers compared with the controls. Attempts were made to limit radiation exposure to personnel, but the employees did not always follow the preset rules. Actually, the adverse effects of low-level radiation were attributed to probability. Overall, workers should obey the radiation protection regulations provided by the government and a national system of radiation protection is needed.

  1. Behavioral Reversion and Dark-Light Choice Behavior in Workers of the Red Wood Ant Formica polyctena.

    Science.gov (United States)

    Symonowicz, Beata; Kieruzel, Maria; Szczuka, Anna; Korczyńska, Julita; Wnuk, Andrzej; Mazurkiewicz, Paweł Jarosław; Chiliński, Michał; Godzińska, Ewa Joanna

    Social insect workers usually start adult life from intranidal tasks and then switch to extranidal activities, but this process may be reversed: foragers may switch again to intranidal brood care. The transition forager - reverted nurse is known as the behavioral reversion. Ant foragers are known to avoid illuminated zones less strongly than intranidal workers, but illumination responses of reverted nurses were so far never investigated. We compared dark-light choice behavior of three classes of workers of the red wood ant Formica polyctena: nurses, foragers and reverted nurses. Sets of ten ants belonging to the same class were tested in "double nests" made of two interconnected test tubes, one kept in darkness and the other exposed to light. The number of ants present in the illuminated zone of each nest (ni) was recorded on 10 sample points at 30 min intervals. The values of ni were lower in nurses than in foragers and reverted nurses and decreased as a function of time in all three groups. Nurses differed from foragers with respect to the dynamics of dark-light choice behavior, but reverted nurses did not differ in that respect either from nurses, or from foragers. Reverted nurses and foragers did not differ significantly from each other with respect to the overall level of avoidance of illuminated zone, nor with respect to the dynamics of dark-light choice behavior. This implies that behavioral reversion is not accompanied by the return of illumination responses of workers of F. polyctena to the state characteristic for nurses.

  2. Physical activity of office workers

    Directory of Open Access Journals (Sweden)

    E Biernat

    2010-12-01

    Full Text Available Inactivity or insufficient physical activity is risk factor for metabolic or cardiovascular diseases. In most of cases the nature of work of office employees does not require high physical efforts and consists mostly of sitting but the reports on leisure activity of office workers are still lacking. Thus, the aim of the study was to assess physical activity of civil and local administration workers and bank officials. 293 randomly selected office workers took part in the study. They were recruited from employees of local (n=97 or civil (n=119 administration authorities or banks (n=77 and subjected to interviews with the use of IPAQ questionnaire (short version. Low physical activity was noted in about 70% of local administration employees, in almost 50% of bank officials and about 35% of workers employed in civil administration. Total daily time spent on sitting was on average 9.7±1.7 hour/day irrespectively of gender or group studied. Very low level of physical activity of Polish office workers may be a result of improper habits of spending spare time, low awareness of beneficial effects of physical activity and still insufficient promotion of healthy/active lifestyle in East-European countries.

  3. Musculoskeletal diseases in forestry workers

    Directory of Open Access Journals (Sweden)

    Vuković Slađana

    2004-01-01

    Full Text Available The most common hazards in the forestry that may induce disorders of the musculoskeletal system are vibrations, unfavorable microclimatic conditions, noise, over-time working hours, work load and long-term repeated movements. The objective of this study was to analyze the prevalence of musculoskeletal diseases and its difference among workers engaged in various jobs in the forestry. Two groups of workers were selected: woodcutters operating with chain-saw (N=33 and other loggers (N=32. Selected workers were of the similar age and had similar total length of employment as well as the length of service in the forestry. Both groups of workers employed in the forestry had the high prevalence of musculoskeletal diseases (woodcutters 69.7% and other loggers 62.5%, respectively. Degenerative diseases of spinal column were very frequent, in dependently of the type of activity in the forestry. Non-significantly higher risk of carpal tunnel syndrome was found in woodcutters with chain-saw compared to workers having other jobs in the forestry (OR=3.09; 95%CI=0.64-19.72. The lateral epicondylitis was found only in woodcutters operating with chain-saw with the prevalence of 18.2%.

  4. The Effects of Changes in the Foreign Worker Quota on the Native Workers under Efficiency Wages

    OpenAIRE

    島田, 章

    2005-01-01

    Assuming a small open economy where wages are determined by the efficiency wage hypothesis, we investigate how the changes in the foreign worker quota affect native worker employment, wage and expected lifetime utility. For this purpose, we assume that the foreign worker quota is smaller than the number of foreign workers who are willing to migrate to the small open economy. We also assume that the per capita effective labor force of native workers is larger than that offoreign workers. We sh...

  5. 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...

  6. Meet the local policy workers

    DEFF Research Database (Denmark)

    Wimmelmann, Camilla L.; Vallgårda, Signild; Jensen, Anja MB

    2017-01-01

    Reporting on an interview and observation based study in Danish municipalities, this article deals with local policy workers, and takes departure in the great variation we observed in implementation of centrally issued health promotion guidelines. We present five types of local policy workers, each...... of whom we found typified a specific way of reasoning and implementing the guidelines. This typology illustrates the diversity found within a group of local policy workers, and helps explain the variability reported in most studies on policy/guideline implementation. On the level of individuals, variation...... in the same positions receiving the same set of guidelines implement them differently, and suggest that local policy workers’ professionally related experiences affect the frames in which they translate the guidelines and decide upon the strategies of implementation. As such, this article illustrates...

  7. 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.

  8. Knowledge Worker Mobility in Context

    DEFF Research Database (Denmark)

    Wright, Mike; Tartari, Valentina; Huang, Kenneth G.

    2018-01-01

    Scholars are paying more attention to knowledge workers (KW) as they gain importance in the knowledge-based economy. Knowledge worker mobility (KWM) can involve various forms of employee and entrepreneurial movements: the transfer of employees from one organization to another either through...... locational movement or through a change in ownership, the transfer of employees within the same organization but in different units and/or geographies, and the spinning off by employees into new ventures. KWM spans a variety of different contexts which have rarely been explored in prior research. We focus...

  9. Noise, Worker Perception, and Worker Concentration in Timber Harvesting Activity

    Directory of Open Access Journals (Sweden)

    Efi Yuliati Yovi

    2012-01-01

    Full Text Available Timber harvesting activities are unquestionably related with high risk of work accidents and health disorders.Such activities were not only burdened the workers with heavy physical workloads due to uneasy workingenvironment, and massive work materials and tools, but also physiopsychologically burdened workers as theywere imposed with both mechanical and acoustic vibrations (noise produced by the chainsaw. However,  it is acommon practice that most of the workers still ignored the importance of the use of noise reduction devices suchas earmuff or ear plug.  This study was aimed to reveal the factual effects of noise on work concentration of theworkers to provide a scientific basis in supporting efforts in improving workers’ attitude.  The results confirmedthat chainsaw might produce noise during operation.  Noise intensities received by both right and left ears werenot significantly different, indicating that left-handed and normal workers received similar degree of noise inboth side of ears. Further, results also showed that there was a significant difference on the perception and workconcentration of chainsaw operators versus sedentary people to the noise.  These findings proved that hearingability of chainsaw operators had declined due to frequent noise exposure.Keywords: timber harvesting, physio-psychological disorder, noise, chainsaw

  10. 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...

  11. [Effects of carbon disulfide on cardiovascular system of workers occupationally exposed to carbon disulfide].

    Science.gov (United States)

    Li, Kui-rong; Wang, Si-hua; Wang, Jing; Su, Dong-mei; Gu, Gui-zhen; Cui, Shou-ming; Yu, Shan-fa

    2012-06-01

    To study the effects of long-term exposure to carbon disulfide (SC(2)) on cardiovascular system of workers. The concentrations of CS(2) were detected in the representative workshops with different exposure levels. The indicators related to cardiovascular system were tested in 633 workers occupationally exposed to CS(2), which included blood pressure, electrocardiogram, blood routine (blood RT), cholesterol (TCHO), triglyceride (TG) and so on. The data were analyzed by chi-square test and multiple logistic regression analysis. The exposure concentration of CS(2) for 389 workers was less than or equal to 5 mg/m(3), which for other 244 workers was higher than 5 mg/m(3). The maximum exposure concentration of CS(2) was 15.73 mg/m(3). There were no significant effects of CS(2) on the electrocardiogram, red blood cells, white blood cells, blood platelet, TCHO and TG of workers. However, the positive effects of CS(2) on blood pressure and negative effects of CS(2) on hemoglobin were found. The rates of high TCHO, TG and hypertension in male workers were significantly higher than those in female workers (P 30 years old) (P cardiovascular system of workers.

  12. Effects of Honey Supplementation in Female Brood Feed on Male and Female Percentages, Growth, and Survival Rate of Crayfish Red Claw (Cherax quadricarinatus Seed

    Directory of Open Access Journals (Sweden)

    Akhmad Taufiq Mukti

    2009-01-01

    Full Text Available The aim of this study was to know effects of honey supplementation in female brood feed on male and female percentages, growth, and survival rate of crayfish red claw seed. The method that used in this study was laboratory scale experiment. The treatments that was applied were addition of honey dosages in female brood feed of crayfish red claw, i.e. 0 (control, 50, 100, 150, 200, 250 and 300 ml/kg feed. Parameters test were male and female percentages, daily growth (G, specific growth rate (SGR and survival rate of crayfish red claw seed. Data analysis that used was descriptive analysis. The result of this study indicated that supplement of honey in female brood feed of crayfish red claw influenced male and female percentages, growth rate, and survival rate of seed. Treatment of honey dosage 300 ml/kg feed has high result, i.e. male percentage was 58,09% (female, 41.09%, daily  growth was 0.59 mm/day, specific growth rate was 0.10% of BW/day, and survival rate was 96.77 %. Treatment of honey dosage 0 ml/kg feed (control showed low result, i.e. male percentage was 46.72 % (female, 53.28%, day growth was 0.55 mm/day, specific growth rate was 0.01%  of BW/day, and survival rate was 94.74%. Keywords: supplementation, honey, crayfish, sex, growth   ABSTRAK Tujuan penelitian ini adalah untuk mengetahui pengaruh suplementasi madu dalam pakan induk betina terhadap persentase jantan dan betina, pertumbuhan dan kelangsungan hidup benih lobster air tawar red claw. Metode yang digunakan dalam penelitian ini adalah eksperimen. Perlakuan yang digunakan adalah penambahan dosis madu dalam pakan induk betina lobster air tawar red claw, yaitu 0 (kontrol, 50, 100, 150, 200, 250 dan 300 ml/kg pakan. Parameter yang diuji adalah persentase jenis kelamin jantan dan betina, pertumbuhan harian (G, laju pertumbuhan spesifik (SGR dan kelangsungan hidup dari benih lobster air tawar red claw. Analisis data yang digunakan adalah deskriptif. Hasil dari penelitian ini

  13. 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 ...

  14. MORPHOMETRIC CHARACTERISTICS OF THE REPLACEMENT-BROOD STOCK OF RAINBOW TROUT (ONCORHYNCHUS MYKISS (WALBAUM, 1792 REARED IN THE CONDITIONS OF THE INDUSTRIAL FISH FARM "SLOBODA-BANYLIV”

    Directory of Open Access Journals (Sweden)

    P. Mendrishora

    2017-09-01

    Full Text Available Purpose. To analyze the results of morphometric measurements and dates of aquaculture-biological characteristics of the young-of-the-year and age-1+ rainbow trout reared under industrial technology at instable conditions of the fish farm “Sloboda-Banyliv”. Methodology. The study has been performed at the industrial fish farm “Sloboda-Banyliv”, Chernivtsi region. The materials for the study were young-of-the-year and age-1+ rainbow trout obtained from the eggs of autumn-spawning form rainbow trout. The young-of-the-year were reared in a 216 m2 tank with stocking density of 255 ind./m2, age-1+ fish were reared in 108 m2 tank with a stocking density of 33 ind./m2 according to generally accepted methods in trout culture. Morphometric measurements of fish were performed according to I.F. Pravdin. Statistical processing of data was carried out in Microsoft Office Excel (2003. The analysis of values was done in the system of absolute values. The analyzed criteria of the measured parameters were their mean values and standard errors (M±m, deviation (σ, variability coefficient (Cv. Fish were fed with the artificial feed with high protein content manufactured by “Biomar” (Denmark. Findings. The studies on rainbow trout rearing under industrial conditions showed that fish body proportions did not change with age, however, the length of their fins decreased. The slenderness coefficient in age-1+ fish decreased insignificantly that is typical with increasing body depth. Despite instable rearing conditions, both young-of-the-year and age-1+ fish were characterized by moderate growth rate and high feed-conversion efficiency. Originality. For the first time, in conditions of Ukraine, a study on the formation of rainbow trout brood stocks in a fish farm with instable rearing conditions was performed with the use of the analysis of phenotypical and productive features. Practical value. The results of the performed work will provide an opportunity to

  15. Productivity in Knowledge Worker Teams

    OpenAIRE

    Moreno Romero, Ana María; Mahou Fernández, Ángel; Varanki, H.

    2013-01-01

    The use of Information and Communication Technologies in work pro- cesses has not brought the expected productivity improvement. Some studies even suggest that the always-on model decreases productivity. This article proposes work teams as a new unit for knowledge worker productivity analysis in organizations. Organizations? ability to adopt new analysis measures is analyzed in three case studies.

  16. Wage inflation and worker uncertainty

    OpenAIRE

    Mark E. Schweitzer

    1997-01-01

    Compares two possible explanations of why pay increases continue to be moderate in a vigorous labor market--workers' uncertainty about their jobs and human resource managers' wage-setting behavior--and looks at how each explanation matches the evidence on the timing of inflation and wage changes.

  17. The Migration of Technical Workers

    DEFF Research Database (Denmark)

    Dahl, Michael S.; Sorenson, Olav

    2010-01-01

    Using panel data on the Danish population, we estimated the revealed preferences of scientists and engineers for the places in which they choose to work. Our results indicate that these technical workers exhibit substantial sensitivity to differences in wages but that they have even stronger pref...

  18. Girl domestic workers in Kenya.

    Science.gov (United States)

    Mzungu, M

    1999-03-01

    This article exposes the conditions among children who are forced by their poor families to assume domestic work in households in Kenya. It is an accepted practice for parents to place daughters in households to help with housework and baby-sitting. The Sinaga Women and Child Labor Resource Center in Nairobi finds this exploitative and part of a wider practice that institutionalizes violence against women. The Center was established in 1995 to challenge the practice of child domestic labor. The Center's research reveals that child domestic workers tend to come from large, poor, and rural families or from urban slums. Wages are low or exchanged for shoes, clothes, and food. The hours of work are long. Mistreatment may include sexual molestation by male household members, beatings, verbal abuse, and mistrust. There is little recourse. Complaints from child workers or others outside the household can result in further mistreatment. Action against mistreatment is complicated by the prevailing image of activists as frustrated women with vendettas against men. The Center focuses on rehabilitation, literacy training, marketable skill development, and awareness creation. Counseling includes parents, children, and employers. Public awareness campaigns have resulted in employer referrals of youth workers for training. Other groups are joining the effort to improve conditions for child domestic workers.

  19. Do working environment interventions reach shift workers?

    DEFF Research Database (Denmark)

    Nabe-Nielsen, Kirsten; Jørgensen, Marie Birk; Garde, Anne Helene

    2016-01-01

    workers were less likely to be reached by workplace interventions. For example, night workers less frequently reported that they had got more flexibility (OR 0.5; 95 % CI 0.3-0.7) or that they had participated in improvements of the working procedures (OR 0.6; 95 % CI 0.5-0.8). Quality of leadership......PURPOSE: Shift workers are exposed to more physical and psychosocial stressors in the working environment as compared to day workers. Despite the need for targeted prevention, it is likely that workplace interventions less frequently reach shift workers. The aim was therefore to investigate whether...... the reach of workplace interventions varied between shift workers and day workers and whether such differences could be explained by the quality of leadership exhibited at different times of the day. METHODS: We used questionnaire data from 5361 female care workers in the Danish eldercare sector...

  20. Workers' Education in Africa: A Fresh Look.

    Science.gov (United States)

    Diallo, Abdoulaye Lelouma

    1988-01-01

    Workers' education is the irreplaceable instrument of trade unions in the exercise of their new functions as they become more complex. Workers' education in Africa must develop in such a way as to meet a plurality of needs. (JOW)

  1. Special Issue: Workers' Education and the Environment.

    Science.gov (United States)

    Labour Education, 1994

    1994-01-01

    Includes papers from symposium on "Workers' Education and the Environment": "All Mobilizing to Contribute" (Taylor); "Trade Union Participation in Environmental Protection and Sustainable Development" (Brett); "ILO's Environment Policy and Programmes" (Kohler); "Workers' Education and the Environment in…

  2. Guest workers in the underground economy

    OpenAIRE

    Djajic, S.; Mesnard, A.

    2013-01-01

    Guest-worker programs have been providing rapidly growing economies with millions of foreign workers over the last couple of decades. With the duration of stay strictly limited by program rules in some host countries and wages paid to guest workers often set at sub-market levels, many migrants choose to overstay and seek unauthorized employment. The model we develop examines how the wage of illegal aliens and the flow of guest workers transiting to undocumented status are affected by the rule...

  3. How foreign-born workers foster exports

    OpenAIRE

    Marchal, Léa; Nedoncelle, Clément

    2017-01-01

    We investigate the export-enhancing effect of foreign workers at the firm level. We first develop a theoretical framework of heterogeneous firms, assuming that foreign workers allow for productivity gains and convey valuable information on foreign markets. We illustrate that foreign workers foster exports at the extensive and the intensive margins. This effect can be decomposed in a general effect - to which any foreign worker contributes - and a destination-specific effect - to which only fo...

  4. Respiratory Disorders Among Workers in Slaughterhouses

    OpenAIRE

    Kasaeinasab, Abbasali; Jahangiri, Mehdi; Karimi, Ali; Tabatabaei, Hamid Reza; Safari, Sonia

    2016-01-01

    Background: Workers in slaughterhouses are exposed to a wide range of biological contaminants, such as bacteria and fungi, due to their working environment. This study aimed to assess the prevalence of respiratory disorders among workers in slaughterhouses. Methods: This study was conducted on 81 workers in slaughterhouses and 81 healthy office workers as a reference group. The American Thoracic Society standard respiratory symptoms questionnaire was used to determine the prevalence of res...

  5. Assessment of potential damage to DNA in urine of coke oven workers: an assay of unscheduled DNA synthesis.

    OpenAIRE

    Roos, F; Renier, A; Ettlinger, J; Iwatsubo, Y; Letourneux, M; Haguenoer, J M; Jaurand, M C; Pairon, J C

    1997-01-01

    OBJECTIVES: A study was conducted in coke oven workers to evaluate the biological consequences of the exposure of these workers, particularly production of potential genotoxic factors. METHODS: 60 coke oven workers and 40 controls were recruited in the same iron and steel works. Exposure to polycyclic aromatic hydrocarbons (PAHs) was assessed by job and measurement of 1-hydroxypyrene (1OHP) in urine samples. An unscheduled DNA synthesis assay was performed on rat pleural mesothelial cells use...

  6. 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.

  7. 29 CFR 780.920 - Workers transported must be fruit or vegetable harvest workers.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Workers transported must be fruit or vegetable harvest workers. 780.920 Section 780.920 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR DIVISION... Employees § 780.920 Workers transported must be fruit or vegetable harvest workers. Clause (B) of section 13...

  8. Students, Temporary Workers and Co-Op Workers: An Experimental Investigation on Social Preferences

    Directory of Open Access Journals (Sweden)

    Davide Dragone

    2015-05-01

    Full Text Available We conduct an artefactual field experiment to compare the individual preferences and propensity to cooperate of three pools of subjects: Undergraduate students, temporary workers and permanent workers. We find that students are more selfish and contribute less than workers. Temporary and permanent contract workers have similar other-regarding preferences and display analogous contribution patterns in an anonymous Public Good Game.

  9. Problems and Conditions of Workers' Organisations in Agriculture and Implications for Workers' Education

    Science.gov (United States)

    Labour Education, 1975

    1975-01-01

    The background, achievements, problems, and future plans of various workers' organizations in agriculture are discussed: International Federation of Plantation, Agricultural, and Allied Workers; Trade Union International of Agricultural, Forestry, and Plantation Workers; World Federation of Agricultural Workers; and the Asian Trade Union College.…

  10. Productivity Strategies Ranking of Knowledge Workers | Najafi ...

    African Journals Online (AJOL)

    It is commonly recognized that knowledge is the only source of core competence in the knowledge based companies, but the productivity rate of Knowledge Workers is always Low. Based on Knowledge Workers' characteristics, in this paper, we seek to identify factors influencing the Productivity of Knowledge Workers, and ...

  11. the Bakery workers in Ibadan, Nigeria.

    African Journals Online (AJOL)

    common during the working hours among the bakery workers and 23.16% of the subjects studied suffered some degree of ... was used to assess the symptoms of the Bakery workers. At the Bakeries, the height and weight of each subject was .... of the safety measures. Finally, education of the workers and the employers is ...

  12. Signaling and Screening of Workers' Motivation

    NARCIS (Netherlands)

    J. Delfgaauw (Josse); A.J. Dur (Robert)

    2005-01-01

    textabstractThis paper develops a model in which workers to a certain extent like to exert effort at the workplace. We examine the implications of workers' motivation for optimal monetary incentive schemes. We show that in the optimum motivated workers work harder and are willing to work for a lower

  13. The Worker's Cooperative = Cooperativas de Trabajadores Duenos.

    Science.gov (United States)

    Hernandez, Mayra Lee

    Written in Spanish and English (on facing pages), this manual is a practical guide for those interested in forming a worker-owned cooperative. It includes examples based on the personal experience of teaching about cooperativism and worker-owned cooperatives to a group of construction workers with diverse levels of education; vocabulary and…

  14. Child Welfare Worker Caseload: What's Just Right?

    Science.gov (United States)

    Yamatani, Hide; Engel, Rafael; Spjeldnes, Solveig

    2009-01-01

    This study was designed to establish a caseload standard for child welfare workers. Understanding reasonable workload expectations for child welfare workers is a cornerstone of quality service provision and the recruitment and retention of qualified workers. Because of the analytic complexity of this question, qualitative and quantitative methods…

  15. 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.

    Directory of Open Access Journals (Sweden)

    Jørgen Olesen

    Full Text Available 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 old. Here we provide new observations on an ovigerous female of Tulumella unidens with advanced developmental stages in its brood chamber collected from an anchialine cave at the Yucatan Peninsula, which is only the third report on developmental stages of Thermosbaenacea and the first for the genus Tulumella. Significant in a wider crustacean context, we report and discuss hitherto unexplored lobate structures inside the brood chamber of the female originating at the first (maxilliped and second thoracic segments, which are most likely modified epipods, perhaps serving as gills. At the posterior margin of carapace of the female are rows of large spines preventing the developing stages from falling out. The external morphology of the advanced developmental stages is described in much detail, providing information on e.g., carapace formation and early limb morphology. Among the hitherto unknown structures in the advanced developmental stages provided by this study are the presence of an embryonic dorsal organ and rudimentary 'naupliar processes' of the second antennae. Since most hypotheses on crustacean (and malacostracan and peracaridan relationship rest on external limb morphology, we use early limb bud morphology of Tulumella to better establish thermosbaenacean limb homologies to those of other crustaceans, which is a necessary basis for future morphology based phylogenetic considerations.

  16. 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.

    Science.gov (United States)

    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 old. Here we provide new observations on an ovigerous female of Tulumella unidens with advanced developmental stages in its brood chamber collected from an anchialine cave at the Yucatan Peninsula, which is only the third report on developmental stages of Thermosbaenacea and the first for the genus Tulumella. Significant in a wider crustacean context, we report and discuss hitherto unexplored lobate structures inside the brood chamber of the female originating at the first (maxilliped) and second thoracic segments, which are most likely modified epipods, perhaps serving as gills. At the posterior margin of carapace of the female are rows of large spines preventing the developing stages from falling out. The external morphology of the advanced developmental stages is described in much detail, providing information on e.g., carapace formation and early limb morphology. Among the hitherto unknown structures in the advanced developmental stages provided by this study are the presence of an embryonic dorsal organ and rudimentary 'naupliar processes' of the second antennae. Since most hypotheses on crustacean (and malacostracan and peracaridan) relationship rest on external limb morphology, we use early limb bud morphology of Tulumella to better establish thermosbaenacean limb homologies to those of other crustaceans, which is a necessary basis for future morphology based phylogenetic considerations.

  17. Greater sage-grouse (Centrocercus urophasianus) nesting and brood-rearing microhabitat in Nevada and California—Spatial variation in selection and survival patterns

    Science.gov (United States)

    Coates, Peter S.; Brussee, Brianne E.; Ricca, Mark A.; Dudko, Jonathan E.; Prochazka, Brian G.; Espinosa, Shawn P.; Casazza, Michael L.; Delehanty, David J.

    2017-08-10

    Greater sage-grouse (Centrocercus urophasianus; hereinafter, "sage-grouse") are highly dependent on sagebrush (Artemisia spp.) dominated vegetation communities for food and cover from predators. Although this species requires the presence of sagebrush shrubs in the overstory, it also inhabits a broad geographic distribution with significant gradients in precipitation and temperature that drive variation in sagebrush ecosystem structure and concomitant shrub understory conditions. Variability in understory conditions across the species’ range may be responsible for the sometimes contradictory findings in the scientific literature describing sage-grouse habitat use and selection during important life history stages, such as nesting. To help understand the importance of this variability and to help guide management actions, we evaluated the nesting and brood-rearing microhabitat factors that influence selection and survival patterns in the Great Basin using a large dataset of microhabitat characteristics from study areas spanning northern Nevada and a portion of northeastern California from 2009 to 2016. The spatial and temporal coverage of the dataset provided a powerful opportunity to evaluate microhabitat factors important to sage-grouse reproduction, while also considering habitat variation associated with different climatic conditions and areas affected by wildfire. The summary statistics for numerous microhabitat factors, and the strength of their association with sage-grouse habitat selection and survival, are provided in this report to support decisions by land managers, policy-makers, and others with the best-available science in a timely manner.

  18. In vitro antibacterial effect of exotic plants essential oils on the honeybee pathogen Paenibacillus larvae, causal agent of American foul brood

    Energy Technology Data Exchange (ETDEWEB)

    Fuselli, S. R.; Garcia de la Rosa, S. B.; Eguaras, M. J.; Fritz, R.

    2010-07-01

    Chemical composition and antimicrobial activity of exotic plants essential oils to potentially control Paenibacillus larvae, the causal agent of American foul brood disease (AFB) were determined. AFB represents one of the main plagues that affect the colonies of honeybees Apis mellifera L. with high negative impact on beekeepers worldwide. Essential oils tested were niaouli (Melaleuca viridiflora) and tea tree (Melaleuca alternifolia) from Myrtaceae, and citronella grass (Cymbopogon nardus) and palmarosa (Cymbopogon martinii) from Gramineae. The components of the essential oils were identified by SPME-GC/MS analysis. The antimicrobial activity of the oils against P. larvae was determined by the broth micro dilution method. In vitro assays of M. viridiflora and C. nardus oils showed the inhibition of the bacterial strains at the lowest concentrations tested, with minimal inhibitory concentration (MIC) mean value about 320 mg L{sup -}1 for both oils, respectively. This property could be attributed to the kind and percentage of the components of the oils. Terpinen-4-ol (29.09%), {alpha}-pinene (21.63%) and limonene (17.4%) were predominant in M. viridiflora, while limonene (24.74%), citronelal (24.61%) and geraniol (15.79%) were the bulk of C. nardus. The use of these essential oils contributes to the screening of alternative natural compounds to control AFB in the apiaries; toxicological risks and other undesirable effects would be avoided as resistance factors, developed by the indiscriminate use of antibiotics. (Author) 40 refs.

  19. Mobile Applications for Knowledge Workers and Field Workers

    OpenAIRE

    Stefan Stieglitz; Christoph Lattemann; Tobias Brockmann

    2015-01-01

    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 worker...

  20. Pulmonary function in automobile repair workers

    Directory of Open Access Journals (Sweden)

    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.

  1. Accommodation training in foreign workers.

    Science.gov (United States)

    Takada, Masumi; Miyao, Masaru; Matsuura, Yasuyuki; Takada, Hiroki

    2013-01-01

    By relaxing the contracted focus-adjustment muscles around the eyeball, known as the ciliary and extraocular muscles, the degree of pseudomyopia can be reduced. This understanding has led to accommodation training in which a visual target is presented in stereoscopic video clips. However, it has been pointed out that motion sickness can be induced by viewing stereoscopic video clips. In Measurement 1 of the present study, we verified whether the new 3D technology reduced the severity of motion sickness in accordance with stabilometry. We then evaluated the short-term effects of accommodation training using new stereoscopic video clips on foreign workers (11 females) suffering from eye fatigue in Measurement 2. The foreign workers were trained for three days. As a result, visual acuity was statistically improved by continuous accommodation training, which will help promote ciliary muscle stretching.

  2. Federal workers' compensation program basics.

    Science.gov (United States)

    Mallon, Timothy M; Grizzell, Tifani L; Nelson, Cameron J L; Nelson, Cameron L; Hodgson, Michael

    2015-03-01

    Primary health care providers may not be familiar with the Federal Employees' Compensation Act (FECA) and Department of Defense regulations that govern injured workers' rights, benefits, and procedures to follow when an injured employee is seen in the military medical treatment facility. The FECA program was examined and each section reviewed to facilitate provider involvement from time of injury to final disposition of a claim and employee return to work. The best practices in case management are highlighted as well. Several areas of the FECA program require coordination between members of the installation Federal Worker's Compensation team. Areas requiring extensive communication by all team members were emphasized. Successful installation FECA programs engage all members of the FECA team in a collaborative fashion to share information, prevent injuries, and keep costs low.

  3. Do working environment interventions reach shift workers?

    Science.gov (United States)

    Nabe-Nielsen, Kirsten; Jørgensen, Marie Birk; Garde, Anne Helene; Clausen, Thomas

    2016-01-01

    Shift workers are exposed to more physical and psychosocial stressors in the working environment as compared to day workers. Despite the need for targeted prevention, it is likely that workplace interventions less frequently reach shift workers. The aim was therefore to investigate whether the reach of workplace interventions varied between shift workers and day workers and whether such differences could be explained by the quality of leadership exhibited at different times of the day. We used questionnaire data from 5361 female care workers in the Danish eldercare sector. The questions concerned usual working hours, quality of leadership, and self-reported implementation of workplace activities aimed at stress reduction, reorganization of the working hours, and participation in improvements of working procedures or qualifications. Compared with day workers, shift workers were less likely to be reached by workplace interventions. For example, night workers less frequently reported that they had got more flexibility (OR 0.5; 95 % CI 0.3-0.7) or that they had participated in improvements of the working procedures (OR 0.6; 95 % CI 0.5-0.8). Quality of leadership to some extent explained the lack of reach of interventions especially among fixed evening workers. In the light of the evidence of shift workers' stressful working conditions, we suggest that future studies focus on the generalizability of results of the present study and on how to reach this group and meet their needs when designing and implementing workplace interventions.

  4. Proteome comparison of hypopharyngeal gland development between Italian and royal jelly producing worker honeybees (Apis mellifera L.).

    Science.gov (United States)

    Jianke, Li; Mao, Feng; Begna, Desalegn; Yu, Fang; Aijuan, Zheng

    2010-12-03

    The hypopharyngeal gland (HG) of the honeybee (Apis mellifera L.) produces royal jelly (RJ) that is essential to feed and raise broods and queens. A strain of bees (high royal jelly producing bee, RJb) has been selected for its high RJ production, but the mechanisms of its higher yield are not understood. In this study, we compared HG acini size, RJ production, and protein differential expressions between the RJb and nonselected honeybee (Italian bee, ITb) using proteomics in combination with an electron microscopy, Western blot, and quantitative real-time PCR (qRT-PCR). Generally, the HG of both bees showed age-dependent changes in acini sizes and protein expression as worker behaviors changed from brood nursing to nectar ripening, foraging, and storage activities. The electron microscopic analysis revealed that the HG acini diameter of the RJb strain was large and produced 5 times more RJ than the ITb, demonstrating a positive correlation between the yield and HG acini size. In addition, the proteomic analysis showed that RJb significantly upregulated a large group of proteins involved in carbohydrate metabolism and energy production, those involved in protein biosynthesis, development, amino acid metabolism, nucleotide and fatty acid, transporter, protein folding, cytoskeleton, and antioxidation, which coincides with the fact that the HGs of the RJb strain produce more RJ than the ITb strain that is owing to selection pressure. We also observed age-dependent major royal jelly proteins (MRJPs) changing both in form and expressional intensity concurrent with task-switching. In addition to MRJPs, the RJb overexpressed proteins such as enolase and transitional endoplasmic reticulum ATPase, protein biosynthesis, and development proteins compared to the ITb strain to support its large HG growth and RJ secretion. Because of selection pressure, RJb pursued a different strategy of increased RJ production by involving additional proteins compared to its original

  5. Bird fanciers lung in mushroom workers.

    Science.gov (United States)

    Hayes, J; Barrett, M

    2015-04-01

    Hypersensitivity pneumonitis has been described in mushrooms workers caused by exposure to mushroom or fungal spores in the compost used to grow mushrooms. We describe two mushroom workers who developed hypersensitivity pneumonitis due to exposure to avian proteins found in poultry manure which was used in producing mushroom compost. Both workers were employed in the compost production area. Both presented with typical features of HP. Both workers had negative serological and precipitin studies to Apergillus fumigatus, Saccarhopolyspora rectivirgula and thermophilic actinomycetes but had positive responses to poultry antibodies. Neither was exposed to mushroom spores. Both workers required initial therapy with corticosteroids. Relocation with avoidance of further exposure resulted in complete cure in one worker and change in work practice with the use of personal protections equipment resulted in the second workerclinical stabilisation. These are the first reported cases of bird fanciers lung in mushroom workers.

  6. Rash in a foreign worker

    OpenAIRE

    Nurjahan, MI; Tevaraj, P

    2016-01-01

    Hookworm-related cutaneous larva migrans (HrCLM) is a zoonosis which is endemic in many sub-tropic and tropical countries including Malaysia. We report a case of a 40-year old plantation worker who presented with a pruritic rash on his abdomen. It is important for clinicians to diagnose and treat HrCLM promptly as this condition results in considerable morbidity when treatment is delayed.

  7. Rash in a foreign worker.

    Science.gov (United States)

    Nurjahan, M I; Tevaraj, P

    2016-01-01

    Hookworm-related cutaneous larva migrans (HrCLM) is a zoonosis which is endemic in many sub-tropic and tropical countries including Malaysia. We report a case of a 40-year old plantation worker who presented with a pruritic rash on his abdomen. It is important for clinicians to diagnose and treat HrCLM promptly as this condition results in considerable morbidity when treatment is delayed.

  8. Evaluation of warehouse workers productivity

    OpenAIRE

    Štěpánková, Anna

    2015-01-01

    The aim of this diploma thesis is to create a new system to measure and evaluate the productivity of warehouse processes in Euromedia books wholesale warehouse. The Warehouse management system (WMS) is implemented in the warehouse, so the company has information about processes within warehouse. However, the system does not have any tool to measure and report the productivity of individual workers and shifts. So the manager of the warehouse does not have enough data for efficient human resour...

  9. Heterogeneous Workers, Trade, and Migration

    OpenAIRE

    Heiland, Inga; Kohler, Wilhelm

    2013-01-01

    We argue that the narrative of variety-induced gains from trade in differentiated goods needs revision. If producing differentiated varieties of a good requires differentiated skills and if the work force is heterogeneous in these skills, then firms are likely to have monopsony power. We show that trade then has adverse labor market effects: It increases the monopsony power of firms and worsens the average quality of matches between firms and workers. We also show that international migration...

  10. Hatchery workers' IgG antibody profiles to airborne bacteria.

    Science.gov (United States)

    Brauner, Paul; Gromöller, Silvana; Pfeifer, Yvonne; Wilharm, Gottfried; Jäckel, Udo

    2017-04-01

    Occupational exposure to high concentrations of airborne bacteria in poultry production is related to an increased risk of respiratory disorders. However, etiology and in particular microorganisms' potential role in pathogenesis still needs to be elucidated. Thus, detection of specific antibodies against occupational microbial antigens may lead to identification of potentially harmful species. For the purpose of IgG titer determination, indirect immunofluorescence on various bacterial isolates from duck hatchery air was combined with image-based quantification of fluorescence intensity. Moreover, in addition to established assays with pure bacterial cultures, a new approach utilized complex bioaerosol samples for detection of anti-microbial antibodies in human sera by determination of percentages of antibody-bound cells in different serum dilutions. Mean titers in sera from hatchery workers and a non-exposed control group did not display significant differences for most tested isolates and application of comprehensive cluster analysis to entire titer data revealed no structure reflecting workers and controls group. Furthermore, determination of immunoreactivity to the complete microbial community in workplace air displayed similar proportions of antibody-bound cells in both groups. Although no general differences in immunoreaction patterns were observed, mean titers to a Proteus mirabilis isolate and to 3 of 4 distinct Acinetobacter baumannii isolates were higher in the group of hatchery workers than in the reference group indicating a potential applicability as exposure markers. We conclude, despite long term bioaerosol exposure, hatchery workers' IgG antibody profiles to tested antigens did not differ substantially from those of the control group. However, increased workers' titers to A. baumannii and clinical relevance of this species should lead to further investigations regarding potential involvement in pathogenesis of occupational respiratory disorders

  11. Foreign workers in South Korea

    Directory of Open Access Journals (Sweden)

    Su-Jin Lim

    2010-07-01

    Full Text Available In today’s global age many people cross national borders in search of better work and more wages. According to IOM, more than 100 000 000 workers leave their homeland and migrate to another country for this reason. Europe and North America have already experienced increase in foreign labor for many decades but nowadays, it is very common to see foreign laborers in Asian countries. As the number of foreign laborers rapidly increased, however, so did many social problems in relation to these workers. No country is safe from or immune to such social problems in regards to the foreign workers especially with a much easier and more efficient transportation system. In case of South Korea, the history of foreign labor may not be as long as other nations but as of 2007, it boasts of more than 250 000 foreign laborers and is thus facing just as many social problems as well. In order to investigate such social issues, this article explores the history of foreign laborers and their current situation in South Korea. Furthermore, this artticle examines both internal and external factors which may have caused exponential growth of foreign labor market in South Korea in the past decade.

  12. Medical interpretation for immigrant workers.

    Science.gov (United States)

    Forst, Linda; Masters, Deborah; Zanoni, Joseph; Avila, Susan; Chaidez, Francisco; Miller, Arlene

    2012-01-01

    Foreign-born workers have high rates of occupational mortality and morbidity, despite downward trends for the U.S. workforce overall. They have limited access to health care services. Medical interpreters (MIs) facilitate care of acutely injured, low-English-proficiency (LEP) patients, including those sustaining occupational injuries. Our goal was to assess the potential for MIs to serve as advocates of LEP patients injured at work and to deliver preventive messages. We conducted interviews and a focus group of MIs regarding their attitudes toward foreign-born workers, knowledge of occupational health, and perceived roles. They were familiar with occupational injuries and sympathetic toward foreign-born workers, and they described their roles as conduits, cultural brokers, and advocates for hospitals, providers, and patients. More detailed and representative data would require a larger investigation. However, the time-sensitive nature of policy-making at this point mandates that occupational health stakeholders participate in the national dialogue on standards, training, and licensure for MIs to promote improved access and quality of health care for LEP patients who have been injured at work.

  13. Occupational health hazards of trichloroethylene among workers in relation to altered mRNA expression of cell cycle regulating genes (p53, p21, bax and bcl-2) and PPARA.

    Science.gov (United States)

    Varshney, Meenu; Chandra, Abhijit; Jain, Rajeev; Ahmad, Riaz; Bihari, Vipin; Chandran, C Keshava; Mudiam, Mohana K R; Patnaik, Satykam; Goel, S K

    2015-01-01

    Trichloroethylene (TCE) is widely used as a metal degreaser in industrial processes. The present study reports on the effects of TCE exposure on workers employed in the lock industries. To ensure exposure of the workers to TCE, its toxic metabolites, trichloroacetic acid (TCA), dichloroacetic acid (DCA) and trichloroethanol (TCEOH) were detected in the plasma of the subjects through solid phase microextraction-gas chromatography-electron capture detection. TCA, DCA and TCEOH were detected in the range of 0.004-2.494 μg/mL, 0.01-3.612 μg/mL and 0.002-0.617 μg/mL, respectively. Quantitative reverse transcription polymerase chain reaction analysis revealed up-regulated expression of p53 (2.4-fold; p  < 0.05), p21 (2-fold; p  < 0.01), bax (2.9-fold; p  < 0.01) mRNAs and down-regulated expression of bcl-2 (67%; p  < 0.05) mRNAs, indicating DNA damaging potential of these metabolites. No effects were observed on the levels of p16 and c-myc mRNAs. Further, as TCA and DCA, the ligand of peroxisome proliferator activated receptor alpha (PPARA), are involved in the process of hepatocarcinogenesis in rodents, we examined expression of PPARA mRNA and let-7c miRNA in the workers. No statistically significant differences in expression of PPARA mRNA and let-7c miRNA in patients were observed as compared to values in controls. Dehydroepiandosterone sulfate (DHEAS) is a reported endogenous ligand of PPARA so its competitive role was also studied. We observed decreased levels of DHEAS hormone in the subjects. Hence, its involvement in mediation of the observed changes in the levels of various mRNAs analyzed in this study appears unlikely.

  14. Factors of lung cancer risks in nuclear mayak pa workers

    Energy Technology Data Exchange (ETDEWEB)

    Tokarshaya, Z. B.; Zhuntova, G. V.; Scott, B. R.; Belyaeva, Z. D.; Khokhryakov, V. F.; Syrchikov, V. A.

    2004-07-01

    Study of the lung cancer incidence in nuclear workers at Mayak Production Association has been continued. The research objective is to compare lung cancer risks after exposure to inhaled compounds of ''239 Pu taken into account possible effect of external g-rays smoking, and chronic non-specific lung diseases. We study 237 cases with lung cancers diagnosed during 1966-2000 with the morphological conformation provided. It is the case-control study of a cohort using the multifactor logistic regression. This report presents research results of the Mayak nuclear workers exposed to insoluble compounds of ''239 Pu. This group includes 28 cases of the lung cancer and 112 control individuals, who had no malignant neoplasms. the control was matched by the gender, age, time of started work at the Mayak PA ''239 PU body burden ranged from 0 to 19.9 kBq; total dose from external g-rays ranged within 0-01 Gy. Distribution of histological tumor types was as follows i. e. adenocarcinoma {approx}50% squamous-cell cancer {approx}25% small-cell cancer {approx} 11% large-cell cancer {approx} 7%, anaplastic cancer {approx} 7%. The frequency of adenocarcinomas in a group of workers exposed to insoluble compounds of ''239 Pu was significantly higher than in the city residents of the same age and gender. (Author)

  15. Long term respiratory health effects in textile workers

    Science.gov (United States)

    Lai, Peggy S.; Christiani, David C.

    2013-01-01

    Purpose of review 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. Recent findings Cessation of exposure to cotton dusts leads to improvement in lung function. Recent animal models have suggested a shift in the lung macrophage:dendritic cell population 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. Summary 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. PMID:23361196

  16. Analysis of piscicultural-biological results of works with Russian sturgeon brood fish at the sturgeon hatchery “Lebyazhy” (Astrakhan region, Russia

    Directory of Open Access Journals (Sweden)

    R. V. Kononenko

    2013-04-01

    Full Text Available The state of world stocks of sturgeons is on the edge of catastrophe. These species are either extinct or under threat of extinction under human impacts. At the same time, there are enterprises, fish hatcheries, which deal with restoration and replenishment of natural stocks with of endangered fish species. One of such hatcheries is the sturgeon hatchery “Lebyazhy” (Astrakhan region, Russian Federation. The aim of the study was an analysis of piscicultural-biological features of the Russian sturgeon brood fish. During the study, which was conducted in April–May 2011, 34 Russian sturgeon females were used in two rounds, 17 individuals each. For stimulating gametes maturation, the Derzhavin’s physiological method was used. Caviar was obtained by stripping the eggs under strict hygienic and sanitary norms. Eggs fertilization with the semi-dry method used the male milt that bought at the “Raskat” LLC. Egg stickiness elimination was performed with the aid of talc and apparatuses for the egg stickiness elimination. Eggs incubation was performed in the “Osetr” apparatuses until yolk-sac larvae hatching. The domesticated fish were subjected to bonitation for determining their readiness for spawning. As a result of this bonitation, the brood fish were separated into two groups: first round of rearing works: females with mean weight of 34.8 kg and age of 9 years; second round: females with mean weight of 32.3 kg and the same age. Among injected females of the first round, 100% positive reaction for the stimulating injection was observed, but 95% – among females of the second round. Maturation time of females of both rounds varied from 25 to 30 hours. The maturation state of gametes of sturgeon females or males was determined based on samples obtained. 90.2 kg of eggs were obtained from females of the first round. At the same time, the maximum quantity was observed in the female of 50.5 kg – 9.2 kg of caviar, and the least quantity

  17. Southeast Asian mouth-brooding Betta fighting fish (Teleostei: Perciformes) species and their phylogenetic relationships based on mitochondrial COI and nuclear ITS1 DNA sequences and analyses

    Science.gov (United States)

    Panijpan, Bhinyo; Kowasupat, Chanon; Laosinchai, Parames; Ruenwongsa, Pintip; Phongdara, Amornrat; Senapin, Saengchan; Wanna, Warapond; Phiwsaiya, Kornsunee; Kühne, Jens; Fasquel, Frédéric

    2014-01-01

    Fighting fish species in the genus Betta are found in several Southeast Asian countries. Depending on the mode of paternal care for fertilized eggs and hatchlings, various species of the betta fish are classified as mouth brooders or nest builders whose members in turn have been grouped according to their similarities mainly in morphology. The mouth brooders as well as some nest builders involved in the present study include fishes discovered and identified subsequent to previous reports on species groupings and their positions on phylogenetic trees based on DNA sequences that differ from those used by us in this study. From the mitochondrial COI gene and nuclear ITS1 gene sequences and more accurate analyses we conclude that the following members of the mouth-brooding pairs, named differently previously, are virtually identical, viz the Betta prima–Betta pallida pair and Betta ferox–Betta apollon pair. The Betta simplex, hitherto believed to be one species, could possibly be genetically split into 2 distinct species. In addition, several other established type-locality fishes could harbor cryptic species as judged by genetic differences. Assignments of fish species to groups reported earlier may have to be altered somewhat by the present genetic findings. We propose here a new Betta fish phylogenetic tree which, albeit being similar to the previous ones, is clearly different from them. Our gene-based evidence also leads to assignments of some fishes to new species groups and alters the positions of some species on the new phylogenetic tree, thus implying different ancestral relationships. PMID:25606468

  18. Sampling locality is more detectable than taxonomy or ecology in the gut microbiota of the brood-parasitic Brown-headed Cowbird (Molothrus ater).

    Science.gov (United States)

    Hird, Sarah M; Carstens, Bryan C; Cardiff, Steven W; Dittmann, Donna L; Brumfield, Robb T

    2014-01-01

    Brown-headed Cowbirds (Molothrus ater) are the most widespread avian brood parasite in North America, laying their eggs in the nests of approximately 250 host species that raise the cowbird nestlings as their own. It is currently unknown how these heterospecific hosts influence the cowbird gut microbiota relative to other factors, such as the local environment and genetics. We test a Nature Hypothesis (positing the importance of cowbird genetics) and a Nurture Hypothesis (where the host parents are most influential to cowbird gut microbiota) using the V6 region of 16S rRNA as a microbial fingerprint of the gut from 32 cowbird samples and 16 potential hosts from nine species. We test additional hypotheses regarding the influence of the local environment and age of the birds. We found no evidence for the Nature Hypothesis and little support for the Nurture Hypothesis. Cowbird gut microbiota did not form a clade, but neither did members of the host species. Rather, the physical location, diet and age of the bird, whether cowbird or host, were the most significant categorical variables. Thus, passerine gut microbiota may be most strongly influenced by environmental factors. To put this variation in a broader context, we compared the bird data to a fecal microbiota dataset of 38 mammal species and 22 insect species. Insects were always the most variable; on some axes, we found more variation within cowbirds than across all mammals. Taken together, passerine gut microbiota may be more variable and environmentally determined than other taxonomic groups examined to date.

  19. Sampling locality is more detectable than taxonomy or ecology in the gut microbiota of the brood-parasitic Brown-headed Cowbird (Molothrus ater

    Directory of Open Access Journals (Sweden)

    Sarah M. Hird

    2014-03-01

    Full Text Available Brown-headed Cowbirds (Molothrus ater are the most widespread avian brood parasite in North America, laying their eggs in the nests of approximately 250 host species that raise the cowbird nestlings as their own. It is currently unknown how these heterospecific hosts influence the cowbird gut microbiota relative to other factors, such as the local environment and genetics. We test a Nature Hypothesis (positing the importance of cowbird genetics and a Nurture Hypothesis (where the host parents are most influential to cowbird gut microbiota using the V6 region of 16S rRNA as a microbial fingerprint of the gut from 32 cowbird samples and 16 potential hosts from nine species. We test additional hypotheses regarding the influence of the local environment and age of the birds. We found no evidence for the Nature Hypothesis and little support for the Nurture Hypothesis. Cowbird gut microbiota did not form a clade, but neither did members of the host species. Rather, the physical location, diet and age of the bird, whether cowbird or host, were the most significant categorical variables. Thus, passerine gut microbiota may be most strongly influenced by environmental factors. To put this variation in a broader context, we compared the bird data to a fecal microbiota dataset of 38 mammal species and 22 insect species. Insects were always the most variable; on some axes, we found more variation within cowbirds than across all mammals. Taken together, passerine gut microbiota may be more variable and environmentally determined than other taxonomic groups examined to date.

  20. Occupational health hazards of trichloroethylene among workers in relation to altered mRNA expression of cell cycle regulating genes (p53, p21, bax and bcl-2 and PPARA

    Directory of Open Access Journals (Sweden)

    Meenu Varshney

    2015-01-01

    Full Text Available Trichloroethylene (TCE is widely used as a metal degreaser in industrial processes. The present study reports on the effects of TCE exposure on workers employed in the lock industries. To ensure exposure of the workers to TCE, its toxic metabolites, trichloroacetic acid (TCA, dichloroacetic acid (DCA and trichloroethanol (TCEOH were detected in the plasma of the subjects through solid phase microextraction-gas chromatography-electron capture detection. TCA, DCA and TCEOH were detected in the range of 0.004–2.494 μg/mL, 0.01–3.612 μg/mL and 0.002–0.617 μg/mL, respectively. Quantitative reverse transcription polymerase chain reaction analysis revealed up-regulated expression of p53 (2.4-fold; p < 0.05, p21 (2-fold; p < 0.01, bax (2.9-fold; p < 0.01 mRNAs and down-regulated expression of bcl-2 (67%; p < 0.05 mRNAs, indicating DNA damaging potential of these metabolites. No effects were observed on the levels of p16 and c-myc mRNAs. Further, as TCA and DCA, the ligand of peroxisome proliferator activated receptor alpha (PPARA, are involved in the process of hepatocarcinogenesis in rodents, we examined expression of PPARA mRNA and let-7c miRNA in the workers. No statistically significant differences in expression of PPARA mRNA and let-7c miRNA in patients were observed as compared to values in controls. Dehydroepiandosterone sulfate (DHEAS is a reported endogenous ligand of PPARA so its competitive role was also studied. We observed decreased levels of DHEAS hormone in the subjects. Hence, its involvement in mediation of the observed changes in the levels of various mRNAs analyzed in this study appears unlikely.

  1. Factors Affecting the Productivity of Government Workers

    Directory of Open Access Journals (Sweden)

    Jerry P. Haenisch

    2012-01-01

    Full Text Available While there have been a variety of studies concerning government worker motivation and productivity, few, if any, studies have focused specifically on state government workers’ perceptions about what factors affect their productivity. With more than 5 million workers employed by state governments in the United States, any improvement in state workplace productivity could have significant financial and service impact for society. In this study, state government workers identified those factors perceived as most affecting their workplace productivity. Data were collected through a survey offered to state government workers in the state of Wyoming. Factor analysis was used to derive key productivity factors from survey responses. The results indicate that state government workers appreciate having freedom and autonomy, like their jobs and the sense of achievement, and welcome teamwork, but feel limited by poor supervision and management, poor communications, and insufficient budgets and staffing. To improve productivity, the workers would eliminate bureaucracy, supervise better, and improve communication.

  2. Hand hygiene among laboratory workers.

    Science.gov (United States)

    Alp, Emine; Haverkate, Diana; Voss, Andreas

    2006-09-01

    We performed a study to measure the compliance of laboratory personnel with different components of hand hygiene. The level of compliance at the end of duty was 100%; however, 36.7% of subjects wore a ring, 46.9% wore a watch, and 6.1% wore a bracelet. Pathogenic microorganisms were exclusively found on hands of laboratory personnel who wore jewelry. After interventions, the level of compliance with the no-jewelry policy among laboratory personnel showed sustained improvement. Efforts to improve hand hygiene should be directed not only at healthcare workers but also at laboratory personnel.

  3. REMEDIATION FACILITY WORKER DOSE ASSESSMENT

    Energy Technology Data Exchange (ETDEWEB)

    V. Arakali; E. Faillace

    2004-02-27

    The purpose of this design calculation is to estimate radiation doses received by personnel in the Remediation Facility performing operations to receive, prepare, open, repair, recover, disposition, and correct off-normal and non-standard conditions with casks, canisters, spent nuclear fuel (SNF) assemblies, and waste packages (WP). The specific scope of work contained in this calculation covers both collective doses and individual worker group doses on an annual basis, and includes the contributions due to external and internal radiation. The results of this calculation will be used to support the design of the Remediation Facility and provide occupational dose estimates for the License Application.

  4. Demotivating factors influencing rubber production workers

    OpenAIRE

    Mohammad Reza Iravani

    2012-01-01

    Motivation is one of the most important factors influencing workers' productivity. An increase in workers' motivation could add more value to organizations' structure and influence the profitability, significantly. In this paper, we study different factors on demotivating workers using questionnaire consist of various questions. The questionnaire is distributed among some employees who work for rubber production units located in Esfahan, Iran. The results of this survey indicate that discrimi...

  5. Productivity spillovers across firms through worker mobility

    OpenAIRE

    Stoyanov, Andrey; Zubanov, Nikolay

    2012-01-01

    Using matched firm-worker data from Danish manufacturing, we observe firm-to-firm worker movements and find that firms that hired workers from more productive firms experience productivity gains one year after the hiring. The productivity gains associated with hiring from more productive firms are equivalent to 0.35 percent per year for an average firm. Surviving a variety of statistical controls, these gains increase with education, tenure, and skill level of new hires, persist for several y...

  6. Career development of South African knowledge workers

    OpenAIRE

    Roelof van Staden; Adeline du Toit

    2011-01-01

    The demand for knowledge workers is on the increase, yet little is known about their career perceptions and attitudes. The objective of this article is to determine the factors affecting the career development of knowledge workers in South Africa. Part-time learners of a postgraduate course were used as a purposive sample and 82 completed questionnaires were received. The results of the online survey provide an interesting look at the unique career issues knowledge workers experience from a S...

  7. Perception of Personal Well-Being and Workers' Compensation Injuries in Federal Correctional Workers

    National Research Council Canada - National Science Library

    Skvore, Casey

    2001-01-01

    .... The physical and psychological demands placed upon these workers are great, and these workers have greater risk factors for occupational injury and disease than do other federal law enforcement officers...

  8. Tax reform for low-wage workers.

    Science.gov (United States)

    Seipel, M M

    2000-01-01

    As a result of the recent implementation of work-oriented antipoverty programs, more welfare recipients can be expected to be working in low-wage jobs. With these jobs there is little hope that these workers' incomes will rise above the poverty level. One way to help support these low-wage workers is through tax reform. Although low-wage workers pay little or no federal tax, they still pay high payroll and local taxes. To help such workers keep more of their earnings, refundable taxes like earned income tax credit and child refund taxes should be expanded, and sales taxes on food should be eliminated.

  9. Characteristics of Menstrual Cycle in Shift Workers

    Science.gov (United States)

    Attarchi, Mirsaeed; Darkhi, Hamidreza; Kashanian, Maryam; khodarahmian, Mahshad; Dolati, Mandana; Ghaffari, Mostafa; Mirzamohammadi, Elham; Mohammadi, Saber

    2013-01-01

    Background: In this study, the characteristics of menstrual cycle in shift workers employed in the pharmaceutical industry are investigated. Method: This study was conducted in a pharmaceutical industrial complex in Tehran in 2012. 406 female workers in packaging units were studied on the menstrual cycle characteristics. The studied workers were divided into two groups of shift workers and non-shift workers and were compared in terms of the frequency of menstrual disorder (short-term cycle, long-term cycle, irregular cycle and bleeding during menstrual cycle) as well as hormonal values (FSH, LH, TSH, and Prolactin). Results: The odds ratio (OR) for menstrual disorder in the shift workers was 5.54 (95% CI=2.78-11.02) compared to the non-shift workers. The mean difference of hormonal values (except prolactin) between shift workers and non-shift workers was not significant (P> 0.05). Conclusion: This study suggests that shift work may disrupt the menstrual cycle. PMID:23618486

  10. Voices of Māori Sex Workers

    OpenAIRE

    Escaravage, Elise

    2016-01-01

    Aotearoa (New Zealand) is the only country in the world to have decriminalized sex work. The Prostitution Reform Act (PRA henceforth) was enacted in 2003 with the aim to safeguard the human rights of sex workers, and create a framework that is conducive to public health. Skeptics of this policy argue that the law reform was targeting indoor workers while the livelihood of street-based sex workers did not see significant improvements (Justice Acts, 2014). It is known that Māori sex workers are...

  11. Privatizing community animal health worker based veterinary ...

    African Journals Online (AJOL)

    Privatizing community animal health worker based veterinary services delivery system in West Kordofan, Southern Sudan; The needed roles of community animal health assistant (CAHA) and Pastoral unions.

  12. Medical surveillance of occupationally exposed workers

    Energy Technology Data Exchange (ETDEWEB)

    2007-05-15

    The guide covers medical surveillance of workers engaged in radiation work and their fitness for this work, protection of the foetus and infant during the worker's pregnancy or breastfeeding, and medical surveillance measures to be taken when the dose limit has been exceeded. The guide also covers recognition of practitioners responsible for medical surveillance of category A workers, medical certificates to be issued to workers, and preservation and transfer of medical records. The medical surveillance requirements specified in this Guide cover the use of radiation and nuclear energy. The guide also applies to exposure to natural radiation in accordance with section 28 of the Finnish Radiation Decree

  13. Anarchy Is a Molecular Signature of Worker Sterility in the Honey Bee.

    Science.gov (United States)

    Ronai, Isobel; Oldroyd, Benjamin P; Barton, Deborah A; Cabanes, Guénaël; Lim, Julianne; Vergoz, Vanina

    2016-01-01

    Worker sterility is a defining characteristic of eusociality. The existence of the sterile worker caste remains a fundamental question for evolutionary biology as it requires the existence of genes that reduce personal reproduction. Currently, little is known about the proximate mechanisms underpinning worker sterility. Studies into a mutant "anarchistic" strain (in which workers can activate their ovaries) of honey bee, Apis mellifera, identified a list of candidate genes that regulate ovary activation. We quantified the expression of the four most promising candidate genes (Anarchy, Pdk1, S6k, and Ulk3) in nonactivated and activated ovaries of wild-type workers. Ovarian expression of Anarchy, a peroxisomal membrane protein, predicts the ovary state of workers with 88.2% accuracy. Increased expression of Anarchy in the ovary is strongly associated with suppression of oogenesis and its expression is sensitive to the presence of the queen. Therefore, Anarchy satisfies key criteria for a "gene underlying altruism". When we knocked down expression of Anarchy in the ovary using RNA interference (RNAi) we altered the expression of Buffy, a gene that regulates programmed cell death. Whole-mount multiplex fluorescent in situ hybridization (mFISH) shows Anarchy transcripts localize to degenerating oocytes within the ovary. Our results suggest that Anarchy is involved in the regulation of oogenesis through programmed cell death. The evolution of facultative worker sterility most likely occurred when the conserved mechanism of programmed cell death was co-opted to regulate ovary activation. Anarchy may therefore be the first example of a gene that has evolved through kin selection to regulate worker sterility. © 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.

  14. The Effect of Pollution on Worker Productivity: Evidence from Call-Center Workers in China

    OpenAIRE

    Chang, Tom; Graff Zivin, Joshua; Gross, Tal; Neidell, Matthew

    2016-01-01

    We investigate the effect of pollution on worker productivity in the service sector by focusing on two call centers in China. Using precise measures of each worker's daily output linked to daily measures of pollution and meteorology, we find that higher levels of air pollution decrease worker productivity by reducing the number of calls that workers complete each day. These results manifest themselves at commonly found levels of pollution in major cities throughout the developing and develope...

  15. Workplace bullying among healthcare workers.

    Science.gov (United States)

    Ariza-Montes, Antonio; Muniz, Noel M; Montero-Simó, María José; Araque-Padilla, Rafael Angel

    2013-07-24

    This paper aims to assess consistent predictors through the use of a sample that includes different actors from the healthcare work force to identify certain key elements in a set of job-related organizational contexts. The utilized data were obtained from the 5th European Working Conditions Survey, conducted in 2010 by the European Foundation for the Improvement of Living and Working Conditions. In light of these objectives, we collected a subsample of 284 health professionals, some of them from the International Standard Classification of Occupations--subgroup 22--(ISCO-08). The results indicated that the chance of a healthcare worker referring to him/herself as bullied increases among those who work on a shift schedule, perform monotonous and rotating tasks, suffer from work stress, enjoy little satisfaction from their working conditions, and do not perceive opportunities for promotions in their organizations. The present work summarizes an array of outcomes and proposes within the usual course of events that workplace bullying could be reduced if job demands were limited and job resources were increased. The implications of these findings could assist human resource managers in facilitating, to some extent, good social relationships among healthcare workers.

  16. Workplace Bullying among Healthcare Workers

    Science.gov (United States)

    Ariza-Montes, Antonio; Muniz, Noel M.; Montero-Simó, María José; Araque-Padilla, Rafael Angel

    2013-01-01

    This paper aims to assess consistent predictors through the use of a sample that includes different actors from the healthcare work force to identify certain key elements in a set of job-related organizational contexts. The utilized data were obtained from the 5th European Working Conditions Survey, conducted in 2010 by the European Foundation for the Improvement of Living and Working Conditions. In light of these objectives, we collected a subsample of 284 health professionals, some of them from the International Standard Classification of Occupations—subgroup 22—(ISCO-08). The results indicated that the chance of a healthcare worker referring to him/herself as bullied increases among those who work on a shift schedule, perform monotonous and rotating tasks, suffer from work stress, enjoy little satisfaction from their working conditions, and do not perceive opportunities for promotions in their organizations. The present work summarizes an array of outcomes and proposes within the usual course of events that workplace bullying could be reduced if job demands were limited and job resources were increased. The implications of these findings could assist human resource managers in facilitating, to some extent, good social relationships among healthcare workers. PMID:23887621

  17. Workplace Bullying among Healthcare Workers

    Directory of Open Access Journals (Sweden)

    María José Montero-Simó

    2013-07-01

    Full Text Available This paper aims to assess consistent predictors through the use of a sample that includes different actors from the healthcare work force to identify certain key elements in a set of job-related organizational contexts. The utilized data were obtained from the 5th European Working Conditions Survey, conducted in 2010 by the European Foundation for the Improvement of Living and Working Conditions. In light of these objectives, we collected a subsample of 284 health professionals, some of them from the International Standard Classification of Occupations—subgroup 22—(ISCO-08. The results indicated that the chance of a healthcare worker referring to him/herself as bullied increases among those who work on a shift schedule, perform monotonous and rotating tasks, suffer from work stress, enjoy little satisfaction from their working conditions, and do not perceive opportunities for promotions in their organizations. The present work summarizes an array of outcomes and proposes within the usual course of events that workplace bullying could be reduced if job demands were limited and job resources were increased. The implications of these findings could assist human resource managers in facilitating, to some extent, good social relationships among healthcare workers.

  18. AGING FACILITY WORKER DOSE ASSESSMENT

    Energy Technology Data Exchange (ETDEWEB)

    R.L. Thacker

    2005-03-24

    The purpose of this calculation is to estimate radiation doses received by personnel working in the Aging Facility performing operations to transfer aging casks to the aging pads for thermal and logistical management, stage empty aging casks, and retrieve aging casks from the aging pads for further processing in other site facilities. Doses received by workers due to aging cask surveillance and maintenance operations are also included. The specific scope of work contained in this calculation covers both collective doses and individual worker group doses on an annual basis, and includes the contributions due to external and internal radiation from normal operation. There are no Category 1 event sequences associated with the Aging Facility (BSC 2004 [DIRS 167268], Section 7.2.1). The results of this calculation will be used to support the design of the Aging Facility and to provide occupational dose estimates for the License Application. The calculations contained in this document were developed by Environmental and Nuclear Engineering of the Design and Engineering Organization and are intended solely for the use of the Design and Engineering Organization in its work regarding facility operation. Yucca Mountain Project personnel from the Environmental and Nuclear Engineering should be consulted before use of the calculations for purposes other than those stated herein or use by individuals other than authorized personnel in Environmental and Nuclear Engineering.

  19. 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

  20. 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

  1. 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.

    2015-01-01

    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

  2. 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

  3. Growing Worker Activism Pushes Envelope in China: Worker Protests Spread, Despite Repression and "Official Unions."

    Science.gov (United States)

    Senser, Robert A.

    2002-01-01

    Asserts that China's rulers are trying to have a free labor market without the freedom, and that the Chinese labor union is actually a branch of the Communist Party. The result is worker exploitation and a burst of worker protests (despite the threat of jail). Describes efforts by Chinese activists to mobilize and empower workers and document…

  4. 20 CFR 617.4 - Benefit information to workers.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Benefit information to workers. 617.4 Section... ASSISTANCE FOR WORKERS UNDER THE TRADE ACT OF 1974 General § 617.4 Benefit information to workers. (a) Providing information to workers. State agencies shall provide full information to workers about the benefit...

  5. 29 CFR 500.72 - Agreements with workers.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Agreements with workers. 500.72 Section 500.72 Labor... SEASONAL AGRICULTURAL WORKER PROTECTION Worker Protections General § 500.72 Agreements with workers. (a... seasonal agricultural workers. Normally, “without justification” would not include situations in which...

  6. Total Worker Health Intervention Increases Activity of Sedentary Workers.

    Science.gov (United States)

    Carr, Lucas J; Leonhard, Christoph; Tucker, Sharon; Fethke, Nathan; Benzo, Roberto; Gerr, Fred

    2016-01-01

    Office employees are exposed to hazardous levels of sedentary work. Interventions that integrate health promotion and health protection elements are needed to advance the health of sedentary workers. This study tested an integrated intervention on occupational sedentary/physical activity behaviors, cardiometabolic disease biomarkers, musculoskeletal discomfort, and work productivity. Two-group, RCT. Data were collected between January and August 2014. Overweight/obese adults working in sedentary desk jobs were randomized to: (1) a health protection-only group (HPO, n=27); or (2) an integrated health protection/health promotion group (HP/HP, n=27). HPO participants received an ergonomic workstation optimization intervention and three e-mails/week promoting rest breaks and posture variation. HP/HP participants received the HPO intervention plus access to a seated activity permissive workstation. Occupational sedentary and physical activity behaviors (primary outcomes), cardiometabolic health outcomes, musculoskeletal discomfort, and work productivity (secondary outcomes) were measured at baseline and post-intervention (16 weeks). The HP/HP group increased occupational light intensity physical activity over the HPO group and used the activity permissive workstations 50 minutes/work day. Significant associations were observed between activity permissive workstation adherence and improvements in several cardiometabolic biomarkers (weight, total fat mass, resting heart rate, body fat percentage) and work productivity outcomes (concentration at work, days missed because of health problems). The HP/HP group increased occupational physical activity and greater activity permissive workstation adherence was associated with improved health and work productivity outcomes. These findings are important for employers interested in advancing the well-being of sedentary office workers. This study is registered at www.clinicaltrials.gov NCT02071420. Copyright © 2016 American Journal

  7. 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

  8. 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...

  9. Molecular Markers of Lung Cancer in MAYAK Workers

    Energy Technology Data Exchange (ETDEWEB)

    Steven A. Belinsky, PhD

    2007-02-15

    The molecular mechanisms that result in the elevated risk for lung cancer associated with exposure to radiation have not been well characterized. Workers from the MAYAK nuclear enterprise are an ideal cohort in which to study the molecular epidemiology of cancer associated with radiation exposure and to identify the genes targeted for inactivation that in turn affect individual risk for radiation-induced lung cancer. Epidemiology studies of the MAYAK cohort indicate a significantly higher frequency for adenocarcinoma and squamous cell carcinoma (SCC) in workers than in a control population and a strong correlation between these tumor types and plutonium exposure. Two hypotheses will be evaluated through the proposed studies. First, radiation exposure targets specific genes for inactivation by promoter methylation. This hypothesis is supported by our recent studies with the MAYAK population that demonstrated the targeting of the p16 gene for inactivation by promoter methylation in adenocarcinomas from workers (1). Second, genes inactivated in tumors can serve as biomarkers for lung cancer risk in a cancer-free population of workers exposed to plutonium. Support for this hypothesis is based on exciting preliminary results of our nested, case-control study of persons from the Colorado cohort. In that study, a panel of methylation markers for predicting lung cancer risk is being evaluated in sputum samples from incident lung cancer cases and controls. The first hypothesis will be tested by determining the prevalence for promoter hypermethylation of a panel of genes shown to play a critical role in the development of either adenocarcinoma and/or SCC associated with tobacco. Our initial studies on adenocarcinoma in MAYAK workers will be extended to evaluate methylation of the PAX5 {alpha}, PAX5 {beta}, H-cadherin, GATA5, and bone morphogenesis 3B (BMP3B) genes in the original sample set described under Preliminary studies. In addition, studies will be initiated in SCC

  10. Keys to Successful Community Health Worker Supervision

    Science.gov (United States)

    Duthie, Patricia; Hahn, Janet S.; Philippi, Evelyn; Sanchez, Celeste

    2012-01-01

    For many years community health workers (CHW) have been important to the implementation of many of our health system's community health interventions. Through this experience, we have recognized some unique challenges in community health worker supervision and have highlighted what we have learned in order to help other organizations effectively…

  11. Assessing the psychological factors predicting workers' output ...

    African Journals Online (AJOL)

    The study investigated job security, communication skills, interpersonal relationship and emotional intelligence as correlates of workers' output among local government employees in Oyo State. The research adopted descriptive design of an expose facto type. The research instruments used includes Workers' output scale, ...

  12. Local Exhaust Optimization and Worker Exposure

    DEFF Research Database (Denmark)

    Heiselberg, Per; Pedersen, Morten; Plath, Thomas

    This paper describes a process of optimisation of exhaust efficiency and of minimisation of worker exposure at a semiautomatic printing machine at a printing office.......This paper describes a process of optimisation of exhaust efficiency and of minimisation of worker exposure at a semiautomatic printing machine at a printing office....

  13. Emotional Exhaustion in Day-Care Workers

    Science.gov (United States)

    Løvgren, Mette

    2016-01-01

    Although childcare workers have the second-worst occupation for work-related health problems and the number of professional day-care centers is growing throughout Europe, few studies have examined these workers' emotional well-being. This study investigates the effect of position, competence, work role, role clarity, and work tasks on emotional…

  14. Do Some Workers Have Minimum Wage Careers?

    Science.gov (United States)

    Carrington, William J.; Fallick, Bruce C.

    2001-01-01

    Most workers who begin their careers in minimum-wage jobs eventually gain more experience and move on to higher paying jobs. However, more than 8% of workers spend at least half of their first 10 working years in minimum wage jobs. Those more likely to have minimum wage careers are less educated, minorities, women with young children, and those…

  15. Foreign workers in Israel : Global perspectives

    NARCIS (Netherlands)

    Drori, Israel

    2009-01-01

    Explores how the entry of migrant workers into Israel raises questions beyond just those of the labor market. Explores how the entry of migrant workers into Israel raises questions beyond just those of the labor market. In this account of a social experiment gone awry, Israel Drori exposes a

  16. Factors influencing healthcare worker's participation in physical ...

    African Journals Online (AJOL)

    Factors influencing healthcare worker's participation in physical activity in one public hospital in South Africa: Do healthcare workers have barriers to exercise? ... African Journal for Physical Activity and Health Sciences ... Employers should seek to eliminate the barriers that discourage use of worksite to increase level of PA.

  17. 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

  18. Lead toxicity in battery workers.

    Science.gov (United States)

    Qasim, Saeeda Fouzia; Baloch, Malka

    2014-11-01

    Lead poisoning is a medical condition caused by increased levels of lead in the body. Routes of exposure include contaminated air, water, soil, food and consumer products. Occupational exposure is the main cause of lead poisoning in the adults. Two cases of occupational lead poisoning in adult battery workers are hereby presented. Both male patients had initial non-specific symptoms of intermittent abdominal pain, fatigue and headache for 6 - 8 years. Later on, they developed psychosis, slurred speech, tremors of hands and initially underwent treatment for Parkinsonism and Wilson's disease because of clinical misdiagnosis. They were diagnosed with lead poisoning later and were treated successfully with lead chelator (CaNa2 EDTA).

  19. Occupational trajectories and immigrant worker health.

    Science.gov (United States)

    Crollard, Allison; de Castro, A B; Tsai, Jenny Hsin-Chun

    2012-11-01

    During their initial years in the receiving country, many immigrants experience occupational downgrading. Downgrading is a loss of occupational status between one's last job in the home country and first job in the receiving country, often resulting in overeducation or overqualification. Although the extent and determinants of such occupational trajectories have been characterized, the connection to immigrant worker health has not been widely examined. However, an emerging body of knowledge indicates that negative health outcomes are associated with overeducation and overqualification in general worker populations, suggesting similar experiences by immigrant workers. This article provides an overview of the magnitude and conceptualization of occupational downgrading, overeducation, and overqualification and discusses implications for immigrant worker health. Occupational health professionals should spearhead research efforts on occupational downgrading, raise public awareness about the issue, and serve as advocates for immigrant workers' rights.

  20. Wage discrimination against foreign workers in Russia

    Directory of Open Access Journals (Sweden)

    Elena Vakulenko

    2017-03-01

    Full Text Available We try to determine with the help of the Oaxaca–Blinder decomposition technique whether foreign workers are discriminated against in Russia. We use the Russian Ministry of Labor (Rostrud data on migrants’ applications and the Russian Longitudinal Monitoring Survey (RLMS, provided by the Higher School of Economics for the period 2009–2013. We show that there is significant discrimination against foreign workers. The average salary of Russian workers with the same level of productivity as migrants exceeds migrants’ average salary by 40%. The industries in which the workers are employed have made most substantial contribution to the discrimination gap. Moreover, there is evidence that the lower salaries of foreign workers do not reduce the salaries of Russians employed in similar positions.

  1. Occupational skin disease in newspaper pressroom workers.

    Science.gov (United States)

    Yakes, B; Kelsey, K T; Seitz, T; Hashimoto, D; Feldman, H A; Christiani, D C

    1991-06-01

    Studies of printing industry tradespeople have reported an increased problem of dermatologic abnormalities, including contact dermatitis and dermatitis attributed to solvent exposure. The current cross-sectional health survey of dermatological conditions were conducted in a follow-up of perceived skin abnormalities among newspaper pressroom workers. We surveyed 215 pressroom workers and 34 compositors at a large northeastern US newspaper printing facility. Our findings indicate that printing pressroom workers reported skin condition symptoms at a significantly higher rate than did the compositor referent group. Pressroom workers also were found to be at a significantly elevated risk of developing dermatitis after self-reported exposure to certain commonly used solvents. This emphasizes the need for proper work practices, product substitution where possible, and appropriate protective glove use by newspaper pressroom workers.

  2. A clinical survey of paraquat formulation workers.

    Science.gov (United States)

    Howard, J K

    1979-08-01

    A group of 18 male Caucasian workers from the United Kingdom and a further group of 18 male mixed race (mainly Malay) workers from Malaysia employed in the formulation of paraquat-based herbicides were examined for evidence of chronic ill health after long-term exposure to paraquat. Clinical records were examined, medical and occupational histories were obtained and a clinical examination, particularly of the skin, was undertaken. Skin rashes, nail damage and epistaxes were encountered by most workers as a result of direct contact of skin and mucous membranes with paraquat. These conditions subsided rapidly and no worker reported any sequelae. There was no clinical evidence of long-term effects on skin, mucous membranes or general health following exposure to paraquat over several years in these workers.

  3. Contact Dermatitis In Automobile Repair workers

    Directory of Open Access Journals (Sweden)

    Joshi M P

    1997-01-01

    Full Text Available Automobile repair workers are at risk of developing skin morbidity including occupational dermatoses because of their exposure to mineral oils, petroleum products and its derivatives and lubricating oil. This cross- sectional study was carried out at Maharashtra State Road Transport Corporation workshops in Nagpur city to investigate prevalence of skin morbidity including contact dermatitis in automobile repair workers. The study included 288 (49.9% automobile repair workers 180 (31.3% workshop office staff and 109 (18.8% divisional office employees. Dermatitis was the commonest skin morbidity in all the study subjects and it was significantly more prevalent in automobile repair workers. Folliculitis was detected in 13.2% of auto â€" repair workers and was not seen in the other two groups. Increasing trend of skin morbidity was correlated with the length of service of employees. Proper protective measures along with suitable washing facilities should be provided

  4. Client Abuse to Public Welfare Workers

    DEFF Research Database (Denmark)

    Strøbæk, Pernille Solveig; Korczynski, Marek

    2016-01-01

    We analyse a case study of workers’ experience of client abuse in a Danish public welfare organisation. We make an original contribution by putting forward two different theoretical expectations of the case. One expectation is that the case follows a pattern of customer abuse processes in a social...... market economy – in which workers are accorded power and resources, in which workers tend to frame the abuse as the outcome of a co-citizen caught in system failure and in which workers demonstrate some resilience to abuse. Another expectation is that New Public Management reforms push the case to follow...... patterns of customer abuse associated with a liberal market economy – in which the customer is treated as sovereign against the relatively powerless worker, and in which workers bear heavy emotional costs of abuse. Our findings show a greater match to the social processes of abuse within a social market...

  5. Strong trade unions meet EEC workers

    DEFF Research Database (Denmark)

    Andersen, Søren Kaj; Hansen, Jens Arnholtz

    2008-01-01

    Although Denmark has not experienced an increase in the number of migrant workers from Eastern Europe to same degree as the UK or Ireland, Danish unions in the construction sector are concerned that the collective bargaining system could be undermined by the presence of Eastern European Country...... (EEC) workers. The argument is that migrant and, in particular, posted workers' conditions of employment often are characterised by evasions of collective agreements, whether in the form of underpayment or other violations of terms and conditions specified in the agreements. However, the trade union...... with distrust on behalf of the migrants. Or should they focus first and foremost on the workplace and aim to organise the EEC workers? Or might they be able to do both? In this article we describe problems and challenges trade unions have faced due to the presence of EEC workers in the Danish construction...

  6. Informal worker phenomenon in housing construction project

    Science.gov (United States)

    Wijayaningtyas, Maranatha; Sipan, Ibrahim; Lukiyanto, Kukuh

    2017-11-01

    The informal workers phenomenon on housing construction projects in Indonesia is different from workers in other sectors who would always request as permanent employees. Substantively, the informal workers are disinclined to be bound as permanent employees which different from the general labor paradigm. Hence, the objective of this study is to find out how the labour selection process, the factors that affected their performance, and the suitable wage system to achieve the target completion of housing construction project. The qualitative method is used to uncover and understand the meaning behind the phenomena (numina) of informal workers action and their influence on housing construction project which called phenomenological approach. Five informal workers and two project managers were selected as informants based on predetermined criteria with in-depth interviews. The results showed that the informal worker were more satisfied with the wage based on unit price while working in the housing construction project for the flexibility in working hours. In addition, the developer was also relieved because they only control the quality and the achievement of the project completion time which supported by informal worker leader. Therefore, these findings are beneficial for both of developer and government as policy maker to succeed the housing program in Indonesia.

  7. Patient aggression perceived by community support workers.

    Science.gov (United States)

    Gale, Christopher; Hannah, Annette; Swain, Nicola; Gray, Andrew; Coverdale, John; Oud, Nico

    2009-12-01

    Objective: Aggression by patients is a known risk factor for hospital workers. Within New Zealand, the bulk of ongoing care for physical and mental disabilities and health issues is not hospital based, but contracted to various non-governmental agencies. The rate of client aggression towards care workers from these organizations, to our knowledge, has not been assessed. Method: Two hundred and forty-two support workers in non-governmental agencies caring for people with disabilities responded to an anonymous mailed survey on client aggression, personal distress, and communication style. Results: Most support workers did experience verbal forms of aggression or destructive behaviour, fewer experienced physical aggression, and a minority were injured, sexually harassed, stalked or harassed by means of formal complaint. The median total violence score was five (interquartile range 12.25). A higher total violence score (using the POPAS-NZ) was associated with age and gender, the primary disability of clients, and the numbers of hours worked. The length of time worked was not associated with total violence risk. Communication style, after correcting for other factors, was a predictor of aggression. Almost 6% of care workers reported distress symptoms at a level associated with clinically significant stress reactions. Conclusions: Patient aggression is common among care workers, and can cause distress in the minority. We suggest that further research to clarify risk factors and develop interventions for care workers is needed.

  8. Respiratory risks in broiler production workers

    Directory of Open Access Journals (Sweden)

    M do CB de Alencar

    2004-03-01

    Full Text Available There are many situations that involve health risks to the Brazilian rural worker, and animal production is just one of them. Inhalation of organic dust, which has many microorganisms, leads in general to respiratory allergic reactions in some individuals, "asthma-like syndrome", and mucous membrane inflammation syndrome, that is a complex of nasal, eye, and throat complaints. Furthermore, workers might have farmer's hypersensitivity pneumonia, that is a respiratory health risk along the years. The objective of this study was to evaluate the potential pulmonary health risks in poultry production workers in the region of Curitiba, PR, Brazil. Interviews using a pre-elaborated questionnaire with 40 questions were made with 37 broiler production workers, which were submitted to a pulmonary function test. Results of restrictive function with lower FEV1 (the maximum respiratory potential, the forced expiratory volume in the first second of exhalation and FVC (forced vital capacity represented 24.32% of the total of workers, and severe obstruction represented 2.70%. Other symptoms were found in 67.57% of the workers as well. The results showed that those who work more than 4 years and within more than one poultry house, exceeding 5 hours per day of work, presented higher pulmonary health risks. It is concluded that the activities within broiler houses may induce allergic respiratory reaction in workers. The use of IPE (individual protection equipment besides special attention to the air quality inside the housing may be advised in a preventive way.

  9. Respiratory Disorders Among Workers in Slaughterhouses.

    Science.gov (United States)

    Kasaeinasab, Abbasali; Jahangiri, Mehdi; Karimi, Ali; Tabatabaei, Hamid Reza; Safari, Sonia

    2017-03-01

    Workers in slaughterhouses are exposed to a wide range of biological contaminants, such as bacteria and fungi, due to their working environment. This study aimed to assess the prevalence of respiratory disorders among workers in slaughterhouses. This study was conducted on 81 workers in slaughterhouses and 81 healthy office workers as a reference group. The American Thoracic Society standard respiratory symptoms questionnaire was used to determine the prevalence of respiratory disorders. Besides, lung function tests were conducted using a calibrated spirometer at the beginning (preshift) and at the end (postshift) of the 1st working day. Single-stage Anderson sampler was used to measure the concentration of bioaerosols in different parts of slaughterhouses. The prevalence of respiratory disorders, such as cough, productive cough, breathlessness, phlegm, and wheezing, was 3.17, 4.02, 3.07, 4.66, and 3.94 times, respectively, higher among workers in slaughterhouses compared with the reference group. The prevalence of respiratory disorders was significantly higher among workers in slaughterhouses. Thus, the significant reduction in the percentage predicted lung function among workers in slaughterhouses might be associated with exposure to bioaerosols in their work environment.

  10. 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

  11. Demotivating factors influencing rubber production workers

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Iravani

    2012-01-01

    Full Text Available Motivation is one of the most important factors influencing workers' productivity. An increase in workers' motivation could add more value to organizations' structure and influence the profitability, significantly. In this paper, we study different factors on demotivating workers using questionnaire consist of various questions. The questionnaire is distributed among some employees who work for rubber production units located in Esfahan, Iran. The results of this survey indicate that discrimination on annual job compensation, entrusting responsibilities and unpleasant relationship with family partner are some of the most important factors influencing employees' motivation. While financial factors play important role on increasing employees' motivation, non-financial factors are considered more important.

  12. Ocular disorders among workers exposed to mercury.

    Science.gov (United States)

    Gabal, M S; Raslan, O A

    1995-01-01

    Mercury vapor exposed workers may show ocular changes, as well as other systems affection. A sample of 84 workers in preparing mercury fulminate were examined for conjunctival corneal and lenticular manifestation of long duration exposure, together with mercury urinary output. Lens changes were found in 50% of the involved workers while keratopathy as recorded in 34.5% of them. No statistically significant association was found between the occurrence of eye lesions and levels of urinary elimination of mercury. These results suggest local absorption of this element is most probably the underlying cause of ocular affection.

  13. Sleep, immunity and shift workers: A review

    Directory of Open Access Journals (Sweden)

    Carlos Mauricio Oliveira de Almeida

    2016-07-01

    Full Text Available To date, shift workers represent between 15% and 25% of the modern day workforce. Work time poses a great challenge to workers as it requires that they balance productivity and sleep time between shifts. As a result, these workers experience chronic sleep deprivation with increased fatigue and drowsiness due to this sleep deprivation. The impact of this kind of work on the immune system is not yet known. We conducted a literature review with the aim of evaluating articles on this specific type of work's effects on sleep and immunity.

  14. [Burnout in emergency health care workers].

    Science.gov (United States)

    Angius, P; Campana, G; Cattari, F; Cattari, M; Pirastru, S; Tintori, A; Serra, A

    2011-01-01

    Some studies reported high levels of severe burnout syndrome in emergency workers. We compared different categories of health care workers (129 of Medicine Department e 47 of Laboratory analysis Department) and emergency workers (42 of 118 and 37 of Emergency Department) Subjects were administered the Organizational Checkup System (OCS) to evaluate subjects' risk of burnout and their perception of their own work role and of their organizational environment The operators of 118 showed a condition of wellbeing and a less tendency to burnout. This Finding was accompanied to a better perception of their own work role and of their organizational environment.

  15. [Workplace accomodations for two workers with narcolepsy].

    Science.gov (United States)

    Vico Garcerán, Belén; Monzó Salas, Monserrat; Cuenca Esteve, Francisco; Luis Domingo, José

    2013-01-01

    We describe the case of two workers evaluated in our occupational health unit. The first worker was a kitchen aide; the second was a primary care physician. Both had been diagnosed with narcolepsy and had obvious disability.We assessed occupational hazards related to their jobs, analysed their tasks, and performed medical examinations. Afterwards, we offered recommendations to the patients, consisting of avoidance of situations involving a risk of work accidents and improving their sleep habits. Narcolepsy is a rare disorder, but it has important social and occupational consequences. A better understanding of the disease and some work accommodations can help improve the quality of life of affected workers.

  16. Educating Brazilian workers about AIDS.

    Science.gov (United States)

    1991-12-01

    This article contains a the script for a slide-tape presentation entitled Working Against AIDS, a presentation developed by the Brazil Family Planning Association (BEMFAM) which is designed to debunk common misconceptions about the disease. This audio-visual, which targets Brazilian workers, can be used during talks, seminars, and meetings. A discussion of the issues involved usually follows the presentation of Working Against AIDS. The presentation contains 30 illustrated slides (these are included in the article). The presentation begins by explaining that much of the information concerning AIDS is prejudicial and misleading. The next few slides point out some of the common misconceptions about AIDS, such as claims denying the existence of the disease, or suggestions that only homosexuals and prostitutes are at risk. The presentation then goes on to explain the ways in which the virus can and cannot be transmitted. Then it discusses how the virus destroys the body's natural defenses and explains the ensuing symptoms. Slides 14 and 15 point out that no cure yet exists for AIDS, making prevention essential. Slides 16-23 explain what actions are considered to be high risk and which ones do not entail risk. Noting that AIDS can be prevented, slide 24 says that the disease should not present an obstacle to spontaneous manifestations of human relations. The next slide explains that condoms should always be used when having sex with someone who could be infected with AIDS. Finally slides 26-30 demonstrate the proper way to use and dispose of a condom.

  17. Progressive silicosis in granite workers

    Science.gov (United States)

    Gründorfer, W.; Raber, A.

    1970-01-01

    Gründorfer, W., and Raber, A.(1970).Brit. J. industr. Med.,27, 110-120. Progressive silicosis in granite workers. The first case of silicosis was discovered in a granite quarry and crushing plant in Lower Austria in 1958 after 30 years of freedom. A routine ϰ-ray survey then revealed no further cases but three more cases were discovered in the next two years. Detailed investigation revealed that these and further cases came from the area where the granite was crushed and loaded. In 10 years 18 cases were found out of a labour force of 170 falling to 120. Average exposure was 15 years and the disease tended to progress. Fifteen of the 18 cases came from the crushing plant where only 20 men were at risk, indicating a very high incidence within 15 years of first exposure. The risk is attributed to increased size and working capacity of the machines without improved dust suppression. This had led to dust levels over 10 times the accepted maximum in places. As well as more effective dust suppression, a reduction in staff, the wearing of masks and effective medical supervision of those particularly at risk are recommended. Images PMID:5428630

  18. Cardiac misconceptions in healthcare workers.

    Science.gov (United States)

    Angus, Neil; Patience, Fiona; Maclean, Elizabeth; Corrigall, Helen; Bradbury, Ian; Thompson, David R; Atherton, Iain; Leslie, Stephen J

    2012-12-01

    Cardiac misconceptions are common and may have a detrimental effect on patients. Such misconceptions may be introduced or reinforced by vague and inconsistent advice from healthcare staff and can adversely affect health outcomes. To assess whether level of cardiac misconceptions significantly differs between groups of healthcare staff based on occupation. The 22-item York cardiac beliefs questionnaire (YCBQ) was administered to a convenience sample of healthcare staff (n = 263) in direct contact with cardiac patients. Data was also collected on the occupation of healthcare staff and years worked. Medical staff had the lowest mean score (17.5, CI 15.6-19.4), indicating fewest misconceptions, and unqualified healthcare workers had the highest mean score (32.1, CI 28.4-35.7). Analysis by ANOVA indicated differences between staff groups to be statistically significant (F = 17.66, p misconception score (Pearson's r = - 0.243, p misconceptions in different groups of healthcare staff. Education to correct cardiac misconceptions should be particularly targeted at unqualified healthcare staff. The importance of maintaining appropriate ratios of qualified to unqualified healthcare staff in the care of cardiac patients is supported by this study.

  19. Comparative proteomic analysis provides insight into 10-hydroxy-2-decenoic acid biosynthesis in honey bee workers.

    Science.gov (United States)

    Yang, Xiao-Hui; Yang, Shi-Fa; Wang, Rui-Ming

    2017-07-01

    10-Hydroxy-2-decenoic acid (10-HDA) is the major compound produced from the mandibular glands (MGs) of honey bee workers. However, little information is available on the molecular mechanisms of 10-HDA biosynthesis. In our study, based on investigating the 10-HDA secretion pattern and the morphological characteristics of MGs from honey bee workers of different ages, a comparative proteomic analysis was performed in the MGs of workers with different 10-HDA production. In total, 59 up-regulated protein species representing 45 unique proteins were identified in high 10-HDA-producing workers by 2-DE-MALDI-TOF/TOF MS. These proteins were involved in carbohydrate/energy metabolism, fatty acid metabolism, protein metabolism and folding, antioxidation, cytoskeleton, development and cell signaling. Proteins related to fatty acid metabolism, including fatty acid synthase and β-oxidation enzymes, are potentially crucial proteins involved in 10-HDA biosynthesis pathway. And RNA interference (RNAi) results demonstrated that knockdown of electron transfer flavoprotein subunit beta (ETF-β), one of the protein related to fatty acid metabolism, decreased 10-HDA production of worker bees, suggesting that ETF-β was necessary for 10-HDA biosynthesis. This study reveals the characteristics of MGs of worker bees at different developmental stages and proteins associated with 10-HDA biosynthesis, which provides the first insight into the molecular mechanism of 10-HDA biosynthesis.

  20. Oxidative Stress and Genotoxicity of Long-Term Occupational Exposure to Low Levels of BTEX in Gas Station Workers

    Directory of Open Access Journals (Sweden)

    Feng Xiong

    2016-12-01

    Full Text Available Atmospheric benzene, toluene, ethylbenzene, and xylenes (BTEX can lead to multiple health injuries. However, what remains uncertain is the effect of long-term exposure to low levels of BTEX. Thus, we determined the BTEX levels in the air from the refueling and office areas in gas stations. Then we collected workers’ (200 refueling vs. 52 office workers peripheral blood samples to analyze the serum total-superoxide dismutase (T-SOD, glutathione (GSH, malondialdehyde (MDA, and 8-hydroxydeoxyguanosine (8-OHdG levels. DNA damage was analyzed by the comet assay and micronucleus test in buccal epithelial cells. We found that the levels of BTEX in refueling areas were significantly higher than those in office areas (p < 0.001. The serum T-SOD and GSH of refueling workers were significantly lower than those in office workers (p < 0.001. By contrast, the serum MDA and 8-OHdG of refueling workers were significantly higher than those of office workers (p < 0.001, MDA; p = 0.025, 8-OHdG. Furthermore, tail and Olive tail moments in refueling workers were longer (p = 0.004, tail moment; p = 0.001, Olive tail moment, and the micronucleus rate was higher (p < 0.001 than those in office workers. Taken together, long-term exposure to low levels of BTEX may reduce the antioxidant ability and increase the risk of DNA damage in refueling workers of gas stations.