Covariation between colony social structure and immune defences of workers in the ant Formica selysi

Several ant species vary in the number of queens per colony, yet the causes and consequences of this variation remain poorly understood. In previous experiments, we found that Formica selysi workers originating from multiple-queen (=polygyne) colonies had a lower resistance to a fungal pathogen than workers originating from single-queen (=monogyne) colonies. In contrast, group diversity improved disease resistance in experimental colonies. This discrepancy between field and experimental colonies suggested that variation in social structure in the field had antagonistic effects on worker resistance, possibly through a down-regulation of the immune system balancing the positive effect of genetic diversity. Here, we examined if workers originating from field colonies with alternative social structure differed in three major components of their immune system. We found that workers from polygyne colonies had a lower bacterial growth inhibitory activity than workers from monogyne colonies. In contrast, workers from the two types of colonies did not differ significantly in bacterial cell wall lytic activity and prophenoloxidase activity. Overall, the presence of multiple queens in a colony correlated with a slight reduction in one inducible component of the immune system of individual workers. This reduced level of immune defence might explain the lower resistance of workers originating from polygyne colonies despite the positive effect of genetic diversity. More generally, these results indicate that social changes at the group level can modulate individual immune defences.

Minu, Startu and all that:- Pitfalls in estimating the sensitivity of a worker’s wage to aggregate unemployment

In this paper we show that the inclusion of unemployment-tenure interaction variates in Mincer wage equations is subject to serious pitfalls. These variates were designed to test whether or not the sensitivity to the business cycle of a worker’s wage varies according to her tenure. We show that three canonical variates used in the literature - the minimum unemployment rate during a worker’s time at the firm(min u), the unemployment rate at the start of her tenure(Su) and the current unemployment rate interacted with a new hire dummy(δu) - can all be significant and "correctly" signed even when each worker in the firm receives the same wage, regardless of tenure (equal treatment). In matched data the problem can be resolved by the inclusion in the panel of firm-year interaction dummies. In unmatched data where this is not possible, we propose a solution for min u and Su based on Solon, Barsky and Parker’s(1994) two step method. This method is sub-optimal because it ignores a large amount of cross tenure variation in average wages and is only valid when the scaled covariances of firm wages and firm employment are acyclical. Unfortunately δu cannot be identified in unmatched data because a differential wage response to unemployment of new hires and incumbents will appear under both equal treatment and unequal treatment.

Surfactant protein-D and exposure to bioaerosols in wastewater and garbage workers.

PURPOSE: Bioaerosols and their constituents, such as endotoxins, are capable of causing an inflammatory reaction at the level of the lung-blood barrier, which becomes more permeable. Thus, it was hypothesized that occupational exposure to bioaerosols can increase leakage of surfactant protein-D (SP-D), a lung-specific protein, into the bloodstream. METHODS: SP-D was determined by ELISA in 316 wastewater workers, 67 garbage collectors, and 395 control subjects. Exposure was assessed with four interview-based indicators and by preliminary endotoxin measurements using the Limulus amoebocyte lysate assay. Influence of exposure on serum SP-D was assessed by multiple linear regression considering smoking, glomerular function, lung diseases, obesity, and other confounders. RESULTS: Overall, mean exposure levels to endotoxins were below 100 EU/m(3). However, special tasks of wastewater workers caused higher endotoxin exposure. SP-D concentration was slightly increased in this occupational group and associated with the occurrence of splashes and contact to raw sewage. No effect was found in garbage collectors. Smoking increased serum SP-D. No clinically relevant correlation between spirometry results and SP-D concentrations appeared. CONCLUSIONS: These results support the hypothesis that inhalation of bioaerosols, even at low concentrations, has a subclinical effect on the lung-blood barrier, the permeability of which increases without associated spirometric changes.

EAACI Position Paper: prevention of work-related respiratory allergies among pre-apprentices or apprentices and young workers.

ABSTRACT: Apprenticeship is a period of increased risk of developing work-related respiratory allergic diseases. There is a need for documents to provide appropriate professional advice to young adults aiming to reduce unsuitable job choices and prevent impairment from their careers. The present document is the result of a consensus reached by a panel of experts from European and non-European countries addressed to allergologists, pneumologists, occupational physicians, primary care physicians, and other specialists interested in this field, which aims to reduce work-related respiratory allergies (rhinoconjunctivitis and asthma) among allergic or nonallergic apprentices and other young adults entering the workforce. The main objective of the document is to issue consensus suggestions for good clinical practice based on existing scientific evidence and the expertise of a panel of physicians.

Morphologic and morphometric aspects of oenocytes of Apis mellifera queens and workers in different phases of life

Oenocytes of adult workers and queens of Apis mellifera L. were studied in different ages or life stages, by means of morphometric and histologic techniques. In workers, the oenocytes were found in the head, near the mandibles and in the abdomen, immersed in the parietal fat body mainly below the sterna, close to the wax gland. In queens, two populations of oenocytes different in size and localization were found within the parietal and visceral fat body, respectively. The oenocytes of workers and queens show the presence of acid lipids and acid phosphatase. The role of these cells in the castes differences is discussed.

Is the Spanish Inheritance and Gift Tax incompatible with the free movement of workers and capital?: The reasoned opinion of the EU Commission IP/10/513

The aim of my speech is answering to the question if the Spanish Inheritance and Gift Tax is incompatible with the free movement of workers and capital. We are going to pay special attention to the European Commission’s request to Spain to change its Inheritance and Gift Tax provisions for Non-Residents or Assets held abroad. In order to answer to the question mentioned above five points will be explained. At first place I am going to describe the infrengement procedure established in the Article 258 that the EU Commission can follow when a Member State doesn’t comply with Community Law. At second place, we are going to explain what is the content of the EU Commission delivered on 5th of may 2010 regarding the spanish Inheritance and Gift Tax. Then, we will analise what establishes the Community Law regarding the freedom of workers and capital and how they are understood by the EU Court of Justice in similar cases. Finally, we are going to provide possible amendments that Spain could undertake.

Effect of a smoking ban on respiratory health in nonsmoking hospitality workers: a prospective cohort study

OBJECTIVE: The aim of this study was to examine the effect of a smoking ban on lung function, fractional exhaled nitric oxide, and respiratory symptoms in nonsmoking hospitality workers. METHODS: Secondhand smoke exposure at the workplace, spirometry, and fractional exhaled nitric oxide were measured in 92 nonsmoking hospitality workers before as well as twice after a smoking ban. RESULTS: At baseline, secondhand smoke-exposed hospitality workers had lung function values significantly below the population average. After the smoking ban, the covariate-adjusted odds ratio for cough was 0.59 (95% confidence interval, 0.36 to 0.93) and for chronic bronchitis 0.75 (95% confidence interval, 0.55 to 1.02) compared with the preban period. CONCLUSIONS: The below-average lung function before the smoking ban indicates chronic damages from long-term exposure. Respiratory symptoms such as cough decreased within 12 months after the ban.

The relationship between HRM practices and organizational commitment of knowledge workers. Facts obtained from Swiss SMEs

This paper explores the effects of human resource management (HRM) practices in Swiss small -to-medium enterprises (SMEs). More specifically, the main objective of this study is to assess the impacts of HRM practices developed in Swiss SMEs upon the commitment of knowledge workers. Using data from a survey of over 198 knowledge workers, this study shows the importance of looking closer at HRM practices and, furthermore, to really investigate the impacts of the different HRM practices on employees' commitment. Results show, for example, that organisational support, procedural justice and the reputation of the organisation may clearly influence knowledge workers' commitment, whereas other HRM practices such as involvement in the decision-making, skills management or even the degree of satisfaction with pay do not have any impact on knowledge workers' commitment.

Underreporting of needlestick and sharps injuries among healthcare workers in a Swiss University Hospital.

OBJECTIVES: To determine 1) rates of needlestick and sharps injuries (NSSIs) not reported to occupational health services, 2) reasons for underreporting and 3) awareness of reporting procedures in a Swiss university hospital. MATERIALS AND METHODS: We surveyed 6,367 employees having close clinical contact with patients or patient specimens. The questionnaire covered age, sex, occupation, years spent in occupation, history of NSSI during the preceding twelve months, NSSI reporting, barriers to reporting and knowledge of reporting procedures. RESULTS: 2,778 questionnaires were returned (43.6%) of which 2,691 were suitable for analysis. 260/2,691 employees (9.7%) had sustained at least one NSSI during the preceding twelve months. NSSIs were more frequent among nurses (49.2%) and doctors performing invasive procedures (IPs) (36.9%). NSSI rate by occupation was 8.6% for nurses, 19% for doctors and 1.3% for domestic staff. Of the injured respondents, 73.1% reported all events, 12.3% some and 14.6% none. 42.7% of doctors performing invasive procedures (IPs) underreported NSSIs and represented 58.6% of underreported events. Estimation that transmission risk was low (87.1%) and perceived lack of time (34.3%) were the most common reasons for non-reporting. Regarding reporting procedures, 80.1% of respondents knew to contact occupational health services. CONCLUSION: Doctors performing IPs have high rates of NSSI and, through self-assessment that infection transmission risk is low or perceived lack of time, high rates of underreporting. If individual risk analyses underestimate the real risk, such underreporting represents a missed opportunity for post-exposure prophylaxis and identification of hazardous procedures. Doctors' training in NSSI reporting merits re-evaluation.

Evaluation of exposure biomarkers in offshore workers exposed to low benzene and toluene concentrations.

Characterize ethylbenzene and xylene air concentrations, and explore the biological exposure markers (urinary t,t-muconic acid (t,t-MA) and unmetabolized toluene) among petroleum workers offshore. Offshore workers have increased health risks due to simultaneous exposures to several hydrocarbons present in crude oil. We discuss the pooled benzene exposure results from our previous and current studies and possible co-exposure interactions. BTEX air concentrations were measured during three consecutive 12-h work shifts among 10 tank workers, 15 process operators, and 18 controls. Biological samples were collected pre-shift on the first day of study and post-shift on the third day of the study. The geometric mean exposure over the three work shifts were 0.02 ppm benzene, 0.05 ppm toluene, 0.03 ppm ethylbenzene, and 0.06 ppm xylene. Benzene in air was significantly correlated with unmetabolized benzene in blood (r = 0.69, p < 0.001) and urine (r = 0.64, p < 0.001), but not with urinary t,t-MA (r = 0.27, p = 0.20). Toluene in air was highly correlated with the internal dose of toluene in both blood (r = 0.70, p < 0.001) and urine (r = 0.73, p < 0.001). Co-exposures were present; however, an interaction of metabolism was not likely at these low benzene and toluene exposures. Urinary benzene, but not t,t-MA, was a reliable biomarker for benzene at low exposure levels. Urinary toluene was a useful biomarker for toluene exposure. Xylene and ethylbenzene air levels were low. Dermal exposure assessment needs to be performed in future studies among these workers.

Workers cooperation within the firm: an analysis using small and medium size firms

We investigate the determinants of teamwork and workers cooperation within the firm. Up to now the literature has almost exclusively focused on workers incentives as the main determinants for workers cooperation. We take a broader look at the firm's organizational design and analyze the impact that different aspects of it might have on cooperation. In particular, we consider the way in which the degree of decentralization of decisions and the use of complementary HRM practices (what we call the .rm.s vertical organizational design) can affect workers'collaboration with each other. We test the model's predictions on a unique dataset on Spanish small and medium size firms containing a rich set of variables that allows us to use sensible proxies for workers cooperation. We find that the decentralization of labor decisions (and to a less extent that of task planning) has a positive impact on workers cooperation. Likewise, cooperation is positively correlated to many of the HRM practices that seem to favor workers'interaction the most. We also confirm the previous finding that collaborative efforts respond positively to pay incentives, and particularly, to group or company incentives.