Stress at work among electric utility workers

In the last decades there was an increase in stress at work and its effects on workers' health. These issues are still little studied in the electric utility sector. This study aims to evaluate factors associated with stress at work and to verify its associations with health status among workers of an electric company in São Paulo State, Brazil. A cross-sectional study was conducted with 474 subjects (87.5% of the eligible workers). Data were collected using self-reported questionnaires. A descriptive analysis, a multiple linear hierarchical regression analysis and a correlation analysis were performed. The majority of participants were males (91.1%) and the mean age was 37.5 yr. The mean score of stress level was 2.3 points (scale ranging from 1.0 to 5.0). Hierarchical multiple analyses showed that: regular practice of physical activities (p=0.025) and individual monthly income (p=0.002) were inversely associated with stress level; BMI was marginally associated with the stress level (p=0.074). The demographic characteristics were not associated with stress. Stress at work was significantly associated with physical and mental health status (p<0.001). To improve health of electric utility workers, actions are suggested to decrease stress by remuneration and an appropriate practice of physical activity aiming reduction of BMI

Work start time and chronotype of indoor and outdoor daytime workers

Introdução e objetivo: A exposição à luz natural tem efeitos relevantes no sistema de temporização biológica. Pode-se supor que essa exposição poderia promover um ajuste melhor entre os ritmos biológicos e os horários de início de trabalho entre trabalhadores diurnos de ambientes externos. O objetivo deste estudo foi comparar a matutinidade/vespertinidade e a relação entre o horário de trabalho real e o ideal em trabalhadores diurnos expostos a condições de iluminação distintas. Métodos: O estudo foi conduzido com dois grupos de trabalhadores (n=49) que residiam em uma área rural e tinham condições sociais similares. Um grupo trabalhava em ambiente interno (n=20, idade média 30,8 anos (21-50); desvio padrão=9,8) e o outro grupo trabalhava em ambiente externo (n=29, idade média 30,8 anos (17- 50); desvio padrão=10,0). Os trabalhadores preencheram um questionário de matutinidade/vespertinidade (MEQ). Foi realizada uma ANOVA de um fator com o intuito de comparar os escores do MEQ entre os dois grupos de trabalhadores. Resultados: Como esperado, o Grupo do Ambiente Externo (GAE) apresentou média de escores mais elevada que o Grupo do Ambiente Interno (GAI), o que significa uma tendência à matutinidade (GAE: 58,4±7,9; GAI; 47,4±6,4), com significância estatística (F=26,22; p<0,001). De acordo com os dados relatados em relação aos horários de trabalho, o GAE gostaria de atrasar seu horário de trabalho em 31 minutos, em média, enquanto que o GAI gostaria de atrasar em 96 minutos seu horário de trabalho (F=7,71; p<0,01). Conclusões: Os resultados desse estudo sugerem que a exposição à luz natural pode promover um ajuste melhor aos horários de início de trabalho matutinos

DESCRIPTION OF THE IMMATURES OF WORKERS OF THE ANT CAMPONOTUS VITTATUS (HYMENOPTERA: FORMICIDAE)

Camponotus vittatus Forel is a poorly studied Neotropical ant, which is very common in Brazil. Larval descriptions are useful to systematics, as larval characters aid with genus-level differentiation, and ant larvae lie at the basis of ant social organization. This study presents the first description of the immatures of C. vittatus with the aid of light and scanning electron microscopy. There are three instars based on the frequency distribution of larval head widths. The larvae had some characteristics typical of Camponotus, specifically, a 'pogono-myrmecoid' body shape, 10 pairs of spiracles, antennae with 3 sensilla, mature larvae with pronounced labial pseudopalps, and conspicuous 'chiloscleres' on the labrum. Unique characteristics found would include the greatest diversity of body hair types recorded in an ant larva and 'camponotoid' mandibles with 6 medial denticles over the blade. The number of antennal sensilla proved variable.

Gender identification of five genera of stingless bees (Apidae, Meliponini) based on wing morphology

Currently, the identification of pollinators is a critical necessity of conservation programs. After it was found that features extracted from patterns of wing venation are sufficient to discriminate among insect species, various studies have focused on this structure. We examined wing venation patterns of males and workers of five stingless bee species in order to determine if there are differences between sexes and if these differences are greater within than between species. Geometric morphometric analyses were made of the forewings of males and workers of Nannotrigona testaceicornis, Melipona quadrifasciata, Frieseomelitta varia, and Scaptotrigona aff. depilis and Plebeia remota. The patterns of males and workers from the same species were more similar than the patterns of individuals of the same sex from different species, and the patterns of both males and workers, when analyzed alone, were sufficiently different to distinguish among these five species. This demonstrates that we can use this kind of analysis for the identification of stingless bee species and that the sex of the individual does not impede identification. Computer-assisted morphometric analysis of bee wing images can be a useful tool for biodiversity studies and conservation programs.

Variations on a theme: diversification of cuticular hydrocarbons in a clade of cactophilic Drosophila

Background: We characterized variation and chemical composition of epicuticular hydrocarbons (CHCs) in the seven species of the Drosophila buzzatii cluster with gas chromatography/mass spectrometry. Despite the critical role of CHCs in providing resistance to desiccation and involvement in communication, such as courtship behavior, mating, and aggregation, few studies have investigated how CHC profiles evolve within and between species in a phylogenetic context. We analyzed quantitative differences in CHC profiles in populations of the D. buzzatii species cluster in order to assess the concordance of CHC differentiation with species divergence. Results: Thirty-six CHC components were scored in single fly extracts with carbon chain lengths ranging from C(29) to C(39), including methyl-branched alkanes, n alkenes, and alkadienes. Multivariate analysis of variance revealed that CHC amounts were significantly different among all species and canonical discriminant function (CDF) analysis resolved all species into distinct, non-overlapping groups. Significant intraspecific variation was found in different populations of D. serido suggesting that this taxon is comprised of at least two species. We summarized CHC variation using CDF analysis and mapped the first five CHC canonical variates (CVs) onto an independently derived period (per) gene + chromosome inversion + mtDNA COI gene for each sex. We found that the COI sequences were not phylogenetically informative due to introgression between some species, so only per + inversion data were used. Positive phylogenetic signal was observed mainly for CV1 when parsimony methods and the test for serial independence (TFSI) were used. These results changed when no outgroup species were included in the analysis and phylogenetic signal was then observed for female CV3 and/or CV4 and male CV4 and CV5. Finally, removal of divergent populations of D. serido significantly increased the amount of phylogenetic signal as up to four out of five CVs then displayed positive phylogenetic signal. Conclusions: CHCs were conserved among species while quantitative differences in CHC profiles between populations and species were statistically significant. Most CHCs were species-, population-, and sex-specific. Mapping CHCs onto an independently derived phylogeny revealed that a significant portion of CHC variation was explained by species' systematic affinities indicating phylogenetic conservatism in the evolution of these hydrocarbon arrays, presumptive waterproofing compounds and courtship signals as in many other drosophilid species.

Gene Expression Profiles in Radiation Workers Occupationally Exposed to Ionizing Radiation

Ionizing radiation OR) imposes risks to human health and the environment. IR at low doses and low (lose rates has the potency to initiate carcinogenesis. Genotoxic environmental agents such as IR trigger a cascade of signal transduction pathways for cellular protection. In this study, using cDNA microarray technique, we monitored the gene expression profiles in lymphocytes derived from radiation-ex posed individuals (radiation workers). Physical dosimetry records on these patients indicated that the absorbed dose ranged from 0.696 to 39.088 mSv. Gene expression analysis revealed statistically significant transcriptional changes in a total of 78 genes (21 up-regulated and 57 clown-regulated) involved in several biological processes such as ubiquitin cycle (UHRF2 and PIAS1), DNA repair (LIG3, XPA, ERCC5, RAD52, DCLRE1C), cell cycle regulation/proliferation (RHOA, CABLES2, TGFB2, IL16), and stress response (GSTP1, PPP2R5A, DUSP22). Some of the genes that showed altered expression profiles in this study call be used as biomarkers for monitoring the chronic low level exposure in humans. Additionally, alterations in gene expression patterns observed in chronically exposed radiation workers reinforces the need for defining the effective radiation dose that causes immediate genetic damage as well as the long-term effects on genomic instability, including cancer.

Evaluating gene by sex and age interactions on cardiovascular risk factors in Brazilian families

Background: In family studies, it is important to evaluate the impact of genes and environmental factors on traits of interest. In particular, the relative influences of both genes and the environment may vary in different strata of the population of interest, such as young and old individuals, or males and females. Methods: In this paper, extensions of the variance components model are used to evaluate heterogeneity in the genetic and environmental variance components due to the effects of sex and age (the cutoff between young and old was 43 yrs). The data analyzed were from 81 Brazilian families (1,675 individuals) of the Baependi Family Heart Study. Results: The models allowing for heterogeneity of variance components by sex suggest that genetic and environmental variances are not different in males and females for diastolic blood pressure, LDL-cholesterol, and HDL-cholesterol, independent of the covariates included in the models. However, for systolic blood pressure, fasting glucose and triglycerides, the evidence for heterogeneity was dependent on the covariates in the model. For instance, in the presence of sex and age covariates, heterogeneity in the genetic variance component was suggested for fasting glucose. But, for systolic blood pressure, there was no evidence of heterogeneity in any of the two variance components. Except for the LDL-cholesterol, models allowing for heterogeneity by age provide evidence of heterogeneity in genetic variance for triglycerides and systolic and diastolic blood pressure. There was evidence of heterogeneity in environmental variance in fasting glucose and HDL-cholesterol. Conclusions: Our results suggest that heterogeneity in trait variances should not be ignored in the design and analyses of gene-finding studies involving these traits, as it may generate additional information about gene effects, and allow the investigation of more sophisticated models such as the model including sex-specific oligogenic variance components.

The family health system: analysis of a health survey in Sao Paulo, Brazil

Background The Family Health Strategy (FHS) has been implemented as a strategy for primary care improvement in Brazil. Working with teams that include one doctor, one nurse, auxiliary nurses and community health workers in predefined areas, the FHS began in 1994 (known then as the Family Health Program) and has since grown considerably. The programme has only recently undergone assessment of outcomes, in contrast to more routine evaluations of infrastructure and process. Methods In 2001, a health survey was carried out in two administrative districts (with 190 000 inhabitants) on the outskirts of the city of Sao Paulo, both partially served by the FHS. Chronic morbidity (hypertension, diabetes and ischaemic heart disease) of individuals aged 15 or older was studied in areas covered and not covered by the programme. Stratified univariate analysis was applied for sex, age, education, income, working status and social insurance of these populations. Multivariate analysis was applied where applicable. Results There was a distinct pattern in the morbidity profile of these populations, suggesting differentiated self-knowledge on chronic disease status in the areas served by the FHS. Conclusion The FHS can increase population awareness of chronic diseases, possibly through increasing access to primary care.

Characterization of Fiber Types in Different Muscles of the Hindlimb in Female Weanling and Adult Wistar Rats

We analyzed lesser diameter and distribution of fiber types in different skeletal muscles from female Wistar rats using a histoenzymology Myofibrillar Adenosine Tri-phosphatase (mATPase) method. Fragments from muscles were frozen and processed by mATPase in different pH. Adult and weanling rat soleus muscles presented a predominance of type I fibers and larger fiber diameters. In the plantar muscle in adult rats, the type IIB fibers demonstrated greater lesser diameter while in the weanling animals, types I and IIB fibers were larger. The plantar muscle of animals of both ages was composed predominantly of the type IID fibers. The type IID fibers were observed in similar amounts in the lateral gastrocnemius and the medial gastrocnemius muscles. Type IIB fibers showed predominance and presented higher size in comparison with other types in the EDL muscle. The present study shows that data on fiber type distribution and fiber lesser diameter obtained in adult animals cannot always be applied to weanling animals of the same species. Using the mATPase, despite the difficult handling, is an important tool to determine the different characteristics of the specific fibers in the skeletal muscle tissue.

Ovariole structure and oogenesis in queens and workers of the stingless bee Melipona quadrifasciata (Hymenoptera: Apidae, Meliponini) kept under different social conditions

The high variability in the reproductive biology of stingless bees makes them very amenable for comparative studies with other eusocial bee taxa. We investigated the structural organization of the ovaries of Melipona quadrifasciata queens and workers kept under different social conditions by analyzing their general histology, mitotic activity, and microfilament organization. The overall dynamics of ovarian activity were similar in the two castes, and at emergence their ovarioles contained a previtellogenic follicle. Stingless bees and honey bees differ in the structural organization in the lower germarium, but they have in common synchronized mitotic activity and putative germ line stem cells in the terminal filament. Unlike honey bees, stingless bee workers lay trophic eggs in addition to reproductive eggs. The overall similarities in oogenesis between the two taxa suggest that the decision to form trophic eggs should only occur in the late stages of oogenesis.

Suppression subtractive hybridization analysis reveals expression of conserved and novel genes in male accessory glands of the ant Leptothorax gredleri

Background: During mating, insect males eject accessory gland proteins (Acps) into the female genital tract. These substances are known to affect female post-mating behavior and physiology. In addition, they may harm the female, e. g., in reducing its lifespan. This is interpreted as a consequence of sexual antagonistic co-evolution. Whereas sexual conflict abounds in non-social species, the peculiar life history of social insects (ants, bees, wasps) with lifelong pair-bonding and no re-mating aligns the reproductive interests of the sexes. Harming the female during mating would negatively affect male fitness and sexual antagonism is therefore not expected. Indeed, mating appears to increase female longevity in at least one ant species. Acps are presumed to play a role in this phenomenon, but the underlying mechanisms are unknown. In this study, we investigated genes, which are preferentially expressed in male accessory glands of the ant Leptothorax gredleri, to determine which proteins might be transferred in the seminal fluid. Results: By a suppression subtractive hybridization protocol we obtained 20 unique sequences (USs). Twelve had mutual best matches with genes predicted for Apis mellifera and Nasonia vitripennis. Functional information (Gene Ontology) was available only for seven of these, including intracellular signaling, energy-dependent transport and metabolic enzyme activities. The remaining eight USs did not match sequences from other species. Six genes were further analyzed by quantitative RT-PCR in three life cycle stages of male ants. A gene with carboxy-lyase activity and one of unpredicted function were significantly overexpressed in accessory glands of sexually mature males. Conclusions: Our study is the first one to investigate differential gene expression in ants in a context related to mating. Our findings indicate that male accessory glands of L. gredleri express a series of genes that are unique to this species, possibly representing novel genes, in addition to conserved ones for which functions can be predicted. Identifying differentially expressed genes might help to better understand molecular mechanisms involved in reproductive processes in eusocial Hymenoptera. While the novel genes could account for rapidly evolving ones driven by intra-sexual conflict between males, conserved genes imply that rather beneficial traits might get fixed by a process described as inter-sexual cooperation between males and females.

Immunological Basis for the Gender Differences in Murine Paracoccidioides brasiliensis Infection

This study aimed to investigate the immunological mechanisms involved in the gender distinct incidence of paracoccidioidomycosis (pcm), an endemic systemic mycosis in Latin America, which is at least 10 times more frequent in men than in women. Then, we compared the immune response of male and female mice to Paracoccidioides brasiliensis infection, as well as the influence in the gender differences exerted by paracoccin, a P. brasiliensis component with carbohydrate recognition property. High production of Th1 cytokines and T-bet expression have been detected in the paracoccin stimulated cultures of spleen cells from infected female mice. In contrast, in similar experimental conditions, cells from infected males produced higher levels of the Th2 cytokines and expressed GATA-3. Macrophages from male and female mice when stimulated with paracoccin displayed similar phagocytic capability, while fungicidal activity was two times more efficiently performed by macrophages from female mice, a fact that was associated with 50% higher levels of nitric oxide production. In order to evaluate the role of sexual hormones in the observed gender distinction, we have utilized mice that have been submitted to gonadectomy followed by inverse hormonal reconstitution. Spleen cells derived from castrated males reconstituted with estradiol have produced higher levels of IFN-gamma (1291+/-15 pg/mL) and lower levels of IL-10 (494+/-38 pg/mL), than normal male in response to paracoccin stimulus. In contrast, spleen cells from castrated female mice that had been treated with testosterone produced more IL-10 (1284+/-36 pg/mL) and less IFN-gamma (587614 pg/mL) than cells from normal female. In conclusion, our results reveal that the sexual hormones had a profound effect on the biology of immune cells, and estradiol favours protective responses to P. brasiliensis infection. In addition, fungal components, such as paracoccin, may provide additional support to the gender dimorphic immunity that marks P. brasiliensis infection.

Consequences for the Bovine Embryo of Being Derived from a Spermatozoon Subjected to Post-Ejaculatory Aging and Heat Shock: Development to the Blastocyst Stage and Sex Ratio

The objective was to determine whether aging of sperm caused by incubation at normothermic (38.5 C) or heat shock (40 C) temperatures for 4 h prior to oocyte insemination affects sperm motility, fertilizing ability, competence of the resultant embryo to develop to the blastocyst stage and blastocyst sex ratio. In the first experiment, the percent of sperm that were motile was reduced by aging (P<0.001) and the reduction in motility was greater for sperm at 40 C compared to sperm at 38.5 C (P<0.01). In the second experiment, oocytes were inseminated with aged sperm. A smaller percent of oocytes fertilized with sperm aged at either temperature cleaved by Day 3 after insemination than oocytes fertilized with fresh sperm (P<0.05). There was no effect of sperm aging on the percent of oocytes or cleaved embryos that developed to the blastocyst stage. Aging of sperm before fertilization at 38.5 C reduced the percent of blastocysts that were male (P=0.08). In the third experiment, incubation of sperm at 38.5 C or 40 C for 4 h did not reduce fertilizing ability of sperm as determined by pronuclear formation at 18 h post insemination. In conclusion, aging of sperm reduced cleavage rate and the percent of blastocysts that were males but had no effect on the developmental capacity of the. embryo. The effect of aging on cleavage rate may represent reduced motility and errors occurring after fertilization and pronuclear formation. Aging at a temperature characteristic of maternal hyperthermia had little additional effect except that polyspermy was reduced. Results indicate that embryo competence for development to the blastocyst stage is independent of sperm damage as a result of aging for 4 h at normothermic or hyperthermic temperatures.

Stress at Work among Electric Utility Workers

In the last decades there was an increase in stress at work and its effects on workers' health. These issues are still little studied in the electric utility sector. This study aims to evaluate factors associated with stress at work and to verify its associations with health status among workers of an electric company in Sao Paulo State, Brazil. A cross-sectional study was conducted with 474 subjects (87.5% of the eligible workers). Data were collected using self-reported questionnaires. A descriptive analysis, a multiple linear hierarchical regression analysis and a correlation analysis were performed. The majority of participants were males (91.1%) and the mean age was 37.5 yr. The mean score of stress level was 2.3 points (scale ranging from 1.0 to 5.0). Hierarchical multiple analyses showed that: regular practice of physical activities (p=0.025) and individual monthly income (p=0.002) were inversely associated with stress level; BMI was marginally associated with the stress level (p=0.074). The demographic characteristics were not associated with stress. Stress at work was significantly associated with physical and mental health status (p<0.001). To improve health of electric utility workers, actions are suggested to decrease stress by remuneration and an appropriate practice of physical activity aiming reduction of BMI.

Spatial patterns in the brood combs of Nannotrigona testaceicornis (Hymenoptera: Meliponinae): male clusters

Genetic models of sex and caste determination in eusocial stingless bees suggest specific patterns of male, worker and gyne cell distribution in the brood comb. Conflict between queen and laying workers over male parentage and center-periphery gradients of conditions, such as food and temperature, could also contribute to non-random spatial configuration. We converted the positions of the hexagonal cells in a brood comb to Cartesian coordinates, labeled by sex or caste of the individuals inside. To detect and locate clustered patterns, the mapped brood combs were evaluated by indexes of dispersion (MMC, mean distance of cells of a given category from their centroid) and eccentricity (DMB, distance between this centroid and the overall brood comb centroid) that we developed. After randomizing the labels and recalculating the indexes, we calculated probabilities that the original values had been generated by chance. We created sets of binary brood combs in which males were aggregated, regularly or randomly distributed among females. These stylized maps were used to describe the power of MMC and DMB, and they were applied to evaluate the male distribution in the sampled Nannotrigona testaceicornis brood combs. MMC was very sensitive to slight deviations from a perfectly rounded clump; DMB detected any asymmetry in the location of these compact to fuzzy clusters. Six of the 82 brood combs of N. testaceicornis that we analyzed had more than nine males, distributed according to variations in spatial patterns, as indicated by the two indexes.