How visual ergonomics interventions influence health and performance - with an emphasis on non-computer work tasks

Visual ergonomics evaluations and interventions were performed on non-computer work tasks at recycling facilities, post sorting facilities and operating theatres. The results can to some extent be applicable to other professions and workplaces. The purpose of the research was to investigate the effects of visual ergonomics interventions on eyestrain, musculoskeletal discomfort, headache, and visual performance at work. Individuals with eyestrain reported more musculoskeletal discomfort than individuals without eyestrain. Factors shown to have an impact on eyestrain and musculoskeletal discomfort were the visual environment, the individual’s perceived visual ability and need for spectacles. Such findings have been reported among computer users. The results presented here show that non-computer work tasks may induce similar findings as well. Evaluations of workplaces and interventions with lighting and spectacles were performed in the studies presented in this thesis. The interventions were evaluated by direct observations such as an expert approach and by indirect observations by means of questionnaires. After the evaluation and measurement of the lighting at the recycling facilities, a number of lighting recommendations were suggested to increase visibility and reduce accident risks. For the younger postal workers in particular, better lighting reduced eyestrain and musculoskeletal discomfort. Pre-intervention, the individuals with eyestrain had lower productivity than those without; their productivity increased with better lighting. The musculoskeletal discomfort from the neck decreased especially from the static side for the postal workers after they were provided with correct power in their spectacles. It is possible to improve the work posture of presbyopic postal workers with customised sorting spectacles, in particular because using the sorting spectacles results in a decrease of the backward tilt of the head. In visually demanding work such as surgery, the luminance contrast within the visual field is essential. This is especially the case for the scrub nurse who has to look into the very bright operating light and also see the less highly lit instrument table and other important aspects in the operating room. The visual focus of the surgeons is in the operating cavity, and their eyes are completely adjusted to that level. It can take up to two minutes before their vision is fully functioning again after being exposed to the high illuminance from the operating cavity. This poses a risk if something happens in the operating room outside the operating cavity that requires good visibility from the surgeon. It is thus vital to increase the general lighting in an operating room, especially around the operating table, to decrease the luminance contrasts and facilitate the operating personnel’s visual ability. In this intervention study, the operating personnel rated the improved lighting as improving their perceived visual ability and a decreasing tiredness. All together, the studies show that visual ergonomics is a multidisciplinary science that requires a holistic approach. This thesis will hopefully contribute to increasing the awareness of the effects of a good visual environment and its benefits for the individual’s health

Personality traits among individuals who as adolescents consulted for a substance use problem

Background: Adolescent antis ocial behavior including substance misuse is associated with negative consequences both for the individual and the society, for example school drop - out, and high costs in the criminal justice and health systems. Further understanding of adolescent substanc e misuse is needed to inform treatment programs. The main aim of this thesis is to advance understanding of personality traits, and most particularly psychopathic traits, among adolescents engaging in substance misuse. Knowledge of these traits, their asso ciations with current and future psychopathology and antisocial and criminal behavior, and their stability as adolescents’ transition to adulthood, is needed to further understanding of the development of substance use disorders and to inform interventions designed to reduce substance misuse. Method : Data were used from a follow - up study of 180 adolescent s (99 women and 81 men) who contacted a substance use clinic in 2007 during a 7 - month period. Data were analysed from the initial assessment and two follo w - ups, 12 months, and five years after inclusion in the study. Results : Four main findings emerged: (1) Two measures of personality, the HP5i and the JTCI presented adequate validity when used among adolescents seeki ng treatment for a substan ce use pro blem. Individuals with externalizing symptoms rated themselves as more impulsive, quick - tempered, and easily board while individuals with internalizing symptoms rated themselves as presenting higher levels of negative feelings. (2) Concurrent and longitudi nal associations between psychopathic traits and symptoms of mental disorders among adolescents who sought treatment for substance misuse. There were positive associations between psychopathic traits and externalizing symptoms . Elevated levels of psychopat hic traits and conduct disorder is a combination of conditions with negative prognosis, findings of the present thesis suggest that oppositional deviant disorder are equally important to assess in girls with high levels of psychopathic traits. Among boys, there was a positive association between psychopathic traits and internalizing symptoms. Lack of negative emotions is a problem among individuals with high levels of psychopathic traits and coping with negative emotions challenging for individuals with int ernalizing symptoms. (3) There was s tability in psychopathic traits from mid - adolescence to early adulthood. Individuals with a high PCL - R score (20 - 40) at the five - years - follow - up showed the greatest stability. (4) There were few f actors associated with c hange in psychopathic traits and scores of psychopathic traits predicted mental health, psychosocial functioning and antisocial/criminal behaviours five years later. Conclusion : In treatment of individuals presenting externalizing problems the trait impul sivity will be important to consider while for those presenting internalizing problems negative emotions will need to be targeted for treatment success. Co - occurring mental disorders among individuals with high levels of psychopathic traits are important t o assess as they may characterize subgroups with antisocial behaviour. Adolescent substance misuse treatment programs may benefit from identifying clients presenting high levels of psychopathic traits and providing them with specific interventions that ta ke account of their personality

A Transient Luminal Chitinous Matrix Is Required to Model Epithelial Tube Diameter in the Drosophila Trachea

SummaryEpithelial tubes are found in many vital organs and require uniform and correct tube diameters for optimal function. Tube size depends on apical membrane growth and subapical cytoskeletal reorganization, but the cues that coordinate these events to ensure functional tube shape remain elusive. We find that epithelial tubes in the Drosophila trachea require luminal chitin polysaccharides to attain the correct diameter. Tracheal chitin forms a broad transient filament within the tubes during the restricted period of expansion. Loss of chitin causes tubular constrictions and cysts associated with irregular subapical cytoskeletal organization, without affecting epithelial integrity and polarity. Analysis of previously identified tube expansion mutants in genes encoding septate junction proteins further suggests that septate junction components may function in tubulogenesis through their role in luminal matrix assembly. We propose that the transient luminal protein/polysaccharide matrix is sensed by the epithelial cells and coordinates cytoskeletal organization to ensure uniform lumen diameter

Lighting Recommendations in Operating Theatres

“The eyes lead the body.” A good visual environment is important for performance and wellbeing. Unsatisfactory visual conditions often induce a strained posture, more or less unconsciously, in an effort to improve vision. The requirements for the visual environment in an operating theatre are high. Surgeons or assistants who are having visual problems can induce treatment hazards. The purpose of this study was to evaluate the visual environment in operating theatres, and also examine if the surgeon’s visual acuity at near work can be improved with better glasses. Thirty percent of the surgeons had eyestrain, and those with eyestrain had three times as much musculoskeletal strain. The measurements of the illuminance and luminance show a low uniformity level on the operating table; the operating lamps give an average of 100.000 lux, while the surrounding area values are much lower. The most important recommendation for lighting intervention in the operating theatre is a more uniform illuminance on the operating table

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