Coupling between bacterioplankton species composition, population dynamics, and organic matter degradation

To study the effect of substrate addition on short term bacterial population dynamics and species composition in seawater, mesocosms were maintained with water collected off Scripps Pier (La Jolla, California, USA). Protein enrichment (BSA) triggered a dynamic response from the microbial food web, whereas enrichment with starch had no effect. In the protein enriched mesocosm the number of both nucleoid-containing cells and metabolically active cells increased by 3.0 x 10(5) cells ml(-1) from Day 1 to Day 4. In the same time period the density of a set of 31 phylogenetically different bacteria (alpha- and gamma-Proteobacteria as well as Flexibacter-Cytophaga-Bacteroides) increased by 3.5 x 10(5) cells ml(-1). The abundance of these isolated bacteria accounted for up to 89 % of the nucleoid-containing cells, and up to 22 % of the total counts. Increased enzyme activities, most notably protease, were found concomitant with a change in bacterial species composition over 3 d. This short term succession was possible due to rapid net growth rates of single bacterial species in the mesocosm (0.48 to 1.6 d(-1)), which was up to 5 times higher than the community turnover calculated from bacterial production and total counts. These results should provide support for studies of actual bacterial population dynamics on the species level and its role in the degradation of organic matter in the aquatic environment

The Functions of Grainy Head-Like Proteins in Animals and Fungi and the Evolution of Apical Extracellular Barriers

The Grainy head (GRH) family of transcription factors are crucial for the development and repair of epidermal barriers in all animals in which they have been studied. This is a high-level functional conservation, as the known structural and enzymatic genes regulated by GRH proteins differ between species depending on the type of epidermal barrier being formed. Interestingly, members of the CP2 superfamily of transcription factors, which encompasses the GRH and LSF families in animals, are also found in fungi – organisms that lack epidermal tissues. To shed light on CP2 protein function in fungi, we characterized a Neurospora crassa mutant lacking the CP2 member we refer to as grainy head-like (grhl). We show that Neurospora GRHL has a DNA-binding specificity similar to that of animal GRH proteins and dissimilar to that of animal LSF proteins. Neurospora grhl mutants are defective in conidial-spore dispersal due to an inability to remodel the cell wall, and we show that grhl mutants and the long-known conidial separation-2 (csp-2) mutants are allelic. We then characterized the transcriptomes of both Neurospora grhl mutants and Drosophila grh mutant embryos to look for similarities in the affected genes. Neurospora grhl appears to play a role in the development and remodeling of the cell wall, as well as in the activation of genes involved in defense and virulence. Drosophila GRH is required to activate the expression of many genes involved in cuticular/epidermal-barrier formation. We also present evidence that GRH plays a role in adult antimicrobial defense. These results, along with previous studies of animal GRH proteins, suggest the fascinating possibility that the apical extracellular barriers of some animals and fungi might share an evolutionary connection, and that the formation of physical barriers in the last common ancestor was under the control of a transcriptional code that included GRH-like proteins

International consensus statement for the screening, diagnosis, and treatment of adolescents with concurrent Attention-Deficit/Hyperactivity Disorder and substance use disorder

Education and Child Studie

Optimal correction in spectacles - intervention effects on eyestrain and musculoskeletal discomfort among postal workers.

The static posture of postal workers when sorting mail can lead to musculoskeletal discomfort. Research has shown a connection between eyestrain and upper-body musculoskeletal discomfort in general, including postal workers. A previous study of postal workers found that most of those with eye strain were in need of a new correction in their existing spectacles

Visual ergonomics interventions in mail sorting facilities

This study was performed between 2004 and 2011 at mail sorting facilities in Sweden. During this time, different interventions were performed. The first was a lighting intervention that had a positive impact on the postal workers, especially those with eyestrain. A new lighting system also improved the illuminance and gave better light distribution. The second intervention involved new personal spectacles for the postal workers who needed them and this had a positive effect on eyestrain. The third intervention involved a specific type of sorting spectacles for the postal workers who already used progressive lenses privately. The reading distances that the postal workers had while sorting the mail was inverted to the distances in their regular progressive lenses. The new sorting spectacles had a positive effect on head postures and on muscular activity

Towards better lighting recommendations for open surgery

This study assesses the lighting requirements for operating theatres and the lighting conditions in a specific test case and proposes alternate ways of achieving a favourable visual environment. The hypothesis was that an increased illuminance level from general lighting and lower luminance contrasts between the essential task areas affect perceived lighting quality, visual ability and performance, as well as tiredness of medical staff performing surgical work. The investigation consisted of three parts: a laboratory study, followed by a field study and concluding with a retrospective study. In the laboratory study, each medical staff subject was exposed to four lighting scenarios with three illuminances from the operating light (12 lighting conditions), with no patients present. In the field and the retrospective study, the existing lighting scenario was compared to the highest-rated test lighting scenario (with illuminances more than double). The field study and the retrospective study took place with medical staff working under either the test general lighting condition or the existing general lighting condition. Increased illuminance from the general lighting and a higher correlated colour temperature did not improve the operating staff’s visual ability. However, medical staff rated the change in lighting quality resulting from the increased general illuminance as an improvement in the work environment, both in the laboratory study and in the field study. Medical staff subjects using the operating theatre rated both perceived visual ability and lighting quality higher under the test lighting scenario. Tiredness was also rated lower under that test scenario. Based on the results from this study, general lighting levels of 2000 lx in the periphery of the operating room, 4000 lx surrounding the operating table and 5500 lx on the operating table are recommended by the authors. With reference to the selections made by the surgeons for the illuminance in the operating cavity, it is suggested that the central beam illuminance from the surgical luminaires be between 50,000 lx and 100,000 lx