Determination of physiological, taxonomic, and molecular characteristics of a cultivable arsenic-resistant bacterial community.

A collection of 219 bacterial arsenic-resistant isolates was constituted from neutral arsenic mine drainage sediments. Isolates were grown aerobically or anaerobically during 21 days on solid DR2A medium using agar or gelan gum as gelling agent, with 7 mM As(III) or 20 mM As(V) as selective pressure. Interestingly, the sum of the different incubation conditions used (arsenic form, gelling agent, oxygen pressure) results in an overall increase of the isolate diversity. Isolated strains mainly belonged to Proteobacteria (63%), Actinobacteria (25%), and Bacteroidetes (10%). The most representative genera were Pseudomonas (20%), Acinetobacter (8%), and Serratia (15%) among the Proteobacteria; Rhodococcus (13%) and Microbacterium (5%) among Actinobacteria; and Flavobacterium (13%) among the Bacteroidetes. Isolates were screened for the presence of arsenic-related genes (arsB, ACR3(1), ACR3(2), aioA, arsM, and arrA). In this way, 106 ACR3(1)-, 74 arsB-, 22 aioA-, 14 ACR3(2)-, and one arsM-positive PCR products were obtained and sequenced. Analysis of isolate sensitivity toward metalloids (arsenite, arsenate, and antimonite) revealed correlations between taxonomy, sensitivity, and genotype. Antimonite sensitivity correlated with the presence of ACR3(1) mainly present in Bacteroidetes and Actinobacteria, and arsenite or antimonite resistance correlated with arsB gene presence. The presence of either aioA gene or several different arsenite carrier genes did not ensure a high level of arsenic resistance in the tested conditions.

Psychosocial safety climate: a multilevel theory of work stress in the health and community service sector.

Work stress is widely thought to be a significant problem in the health and community services sector. We reviewed evidence from a range of different data sources that confirms this belief. High levels of psychosocial risk factors, psychological health problems and workers compensation claims for stress are found in the sector. We propose a multilevel theoretical model of work stress to account for the results. Psychosocial safety climate (PSC) refers to a climate for psychological health and safety. It reflects the balance of concern by management about psychological health v. productivity. By extending the health erosion and motivational paths of the Job Demands-Resources model we propose that PSC within work organisations predicts work conditions and in turn psychological health and engagement. Over and above this, however, we expect that the external environment of the sector particularly government policies, driven by economic rationalist ideology, is increasing work pressure and exhaustion. These conditions are likely to lead to a reduced quality of service, errors and mistakes.

Assessment of heavy metal bioavailability using Escherichia coli zntAp::lux and copAp::lux-based biosensors.

To determine the amount of metals detectable by bacteria, two plasmids were constructed in which the metal-inducible zntA and copA promoters from Escherichia coli were fused to a promoterless Vibrio fischeri luxCDABE operon. The luminescence response of E. coli bearing these constructs was studied as a function of the concentration of several heavy metals and was shown to be influenced by cell growth phase. The zntAp::lux fusion is induced mainly by salts of cadmium, lead, mercury and zinc, with significant induction by other metal ions, whereas the specificity of copA induction is restricted to copper and silver. In optimized assay conditions, metals could be detected at threshold concentrations ranging from nanomolar to micromolar, with maximal induction observed after only 60-100 min incubation. The ability of these biosensor strains to distinguish bioavailable quantities of metals in a sample makes them good candidates as useful tools to monitor metal contamination in environmental samples.

Representation of work stress in an Australian public hospital. A case study.

Content analysis of the view of occupational stress presented in the Annual Reports of an Australian public hospital revealed scant attention to occupational health and safety issues and less still to the issue of workplace stress. The hospital aimed to "provide for all employees a working environment with maximum job satisfaction and opportunities for personal growth," yet stepped up surveillance of "sick leave not absolutely necessary or related to medical conditions." Investigation of the hospital's employee assistance programs revealed a "band aid" approach of individually focused stress management techniques rather than preventative organizational procedures. The researchers concluded that management considered workplace stress to be a problem in the employee not in the workplace, evident also in an increase of almost 1,000% in the number of clients visiting the staff counseling center in a 10 year period. Although a shift to focus on prevention was noticed in most recent reports consistent with the World Health Organization's target of stress prevention, the holistic public safety of workers appears an unmet challenge in this health industry.

Predicting work stress compensation claims and return to work in welfare workers.

Occupational stress is prevalent in work areas in which there is high contact with distressed or dependent members of the public. However, little is known about the prediction and management of stress-related compensation claims, which can be expensive for employers. The authors interviewed all staff members of a large public sector welfare agency who had made a compensation claim for work-related stress during a 12-month period (N = 19) and obtained in-depth information from 16 of the 17 who were still available. A clear relationship was found between type of stress precipitant and length of stress-related leave, suggesting that the organizational response to specific stressful incidents was much more effective than its response to chronic work stressors. Demographic data for all 19 claimants showed that they had taken twice as many days of sick leave as the organizational average in the year preceding their claim. There are important implications for personnel management practices that may reduce and prevent work stress for vulnerable workers.

A test of the demand-control/support model of work stress in correctional officers.

The demand-control/support model of work stress was tested in a sample of 419 correctional officers. The results suggest a link between certain work characteristics (high demands, low control, and low support) and strain symptoms (e.g., psychological distress, job dissatisfaction) as well as with negative affectivity (NA). On the other hand, other job characteristics (high demands and high control) were associated with positive behavioral outcomes (seeking feedback, looking at work as a challenge). Workers in high-isolation strain jobs with the greatest work exposure showed higher levels of strain and NA than workers with less experience working in the same job. Results suggest that work experience may affect long-term personality evolution. It is concluded that studies that control for the nuisance aspects of trait NA may underestimate the impact of the work environment on strain.

Trait anxiety, work demand, social support and psychological distress in correctional officers.

Abstract This study examined the role of social support in the relationship between work demand and psychological distress (GHQ 12) in correctional officers (N=419), a high stress occupational group. Work demands were positively associated with strain. There was no evidence that social support buffered the negative impact of work demands. Rather, consistent with most previous research findings, support showed direct benefits and these were discussed in the context of worker participation and control. The hypothesis that officers high in negative affectivity, as measured by trait anxiety would show greater reactivity to work demands was not supported. However, trait anxiety appeared to inflate the relationship between work stressors (work demand and work support) and psychological distress supporting recent suggestions that the role of trait anxiety in occupational stress should not be disregarded. Trait anxiety combined additively with work demand to predict individual differences in psychological distress, however social support moderated the impact of trait anxiety on strain.

Physical and mechanical properties of joints (the pathomechanics of articular cartilage degeneration).

A review of the literature was performed to determine current theories regarding the physiology of human articular cartilage. The process of chondrodegeneration in rheumatoid arthritis and osteoarthritis was then discussed. Clinical pedal pathology was used to emphasize important but abstract concepts.

Selected soft tissue malignancies of the foot: an in-depth study with case reports.

Soft tissue malignancies represent a diagnostic and therapeutic challenge to the podiatric physician. In order to improve prognosis and increase survival rates of affected patients, prompt clinical and histologic recognition of suspect lesions is necessary. Here we present information and case reports on selected soft tissue malignancies including Kaposi's sarcoma, malignant melanoma, synovial sarcoma, and epithelioid sarcoma to aid the practitioner in recognizing these serious lesions that occur in the foot.

The Evans calcaneal osteotomy for correction of flexible flatfoot syndrome.

The Evans calcaneal osteotomy is used to correct the flexible flatfoot deformity. The procedure restores functional integrity to the medial longitudinal arch and reestablishes the locking mechanism of the midtarsal joint complex. A preliminary analysis of 36 cases (50 feet) performed at Atlanta Hospital and Medical Center during the past 3 years has yielded favorable results.

[Heredity and prevention of atopy]. / Hérédité et prévention de l'atopie.

Although clinical studies have been supplying strong arguments in favour of a hereditary transmission of atopy for a long time, the latest works have not made it possible yet to specify the biologic support of this heredity. An obvious correlation, especially, has not been demonstrated between, on the one hand, atopic ground and HLA group and, on the other hand, between a high production of total IgE and HLA group. At present, the production of specific IgE only seems to be really subordinated to the HLA system; it is likely to be the expression of complex immunological disorders of a genetic determinism. Various environmental factors will contribute, on this predisposed ground, to the disclosure or to the worsening of the atopy. Some prevention of atopy may be undertaken. Extended breast feeding, eviction of some environmental nuisance and family affective balance thus represent useful preventive measures. The influence of the date of conception and of the pregnancy and delivery conditions does not appear to be insignificant; but, there, the prevention is more difficult to set up. Finally, the counting of the IgE in the cord blood could lead to the detection of high-risk newborns.