A Systematic Screen for Tube Morphogenesis and Branching Genes in the Drosophila Tracheal System

Many signaling proteins and transcription factors that induce and pattern organs have been identified, but relatively few of the downstream effectors that execute morphogenesis programs. Because such morphogenesis genes may function in many organs and developmental processes, mutations in them are expected to be pleiotropic and hence ignored or discarded in most standard genetic screens. Here we describe a systematic screen designed to identify all Drosophila third chromosome genes (∼40% of the genome) that function in development of the tracheal system, a tubular respiratory organ that provides a paradigm for branching morphogenesis. To identify potentially pleiotropic morphogenesis genes, the screen included analysis of marked clones of homozygous mutant tracheal cells in heterozygous animals, plus a secondary screen to exclude mutations in general “house-keeping” genes. From a collection including more than 5,000 lethal mutations, we identified 133 mutations representing ∼70 or more genes that subdivide the tracheal terminal branching program into six genetically separable steps, a previously established cell specification step plus five major morphogenesis and maturation steps: branching, growth, tubulogenesis, gas-filling, and maintenance. Molecular identification of 14 of the 70 genes demonstrates that they include six previously known tracheal genes, each with a novel function revealed by clonal analysis, and two well-known growth suppressors that establish an integral role for cell growth control in branching morphogenesis. The rest are new tracheal genes that function in morphogenesis and maturation, many through cytoskeletal and secretory pathways. The results suggest systematic genetic screens that include clonal analysis can elucidate the full organogenesis program and that over 200 patterning and morphogenesis genes are required to build even a relatively simple organ such as the Drosophila tracheal system

Conceptual and Practical Strategy Work to Promote Ergonomics/Human Factors in Sweden

This paper describes the results of the conceptual and practical strategy work performed by the Swedish Ergonomics and Human Factors Society (EHSS) today. The rationale of EHSS is to strengthen the quality of ergonomics/human factors knowledge and practice in Sweden and form a multidisciplinary platform across disciplines and professions for collaboration and for knowledge sharing. EHSS gathers about 350 members, representing different occupations in industry, academia and the public sector. Together, EHSS members hold knowledge and experience in physical, cognitive and organizational ergonomics and its application in working life and society. The overall aim of this paper is to inspire related societies and stakeholders to initiate discussions about strategies and future projects that allow for collaboration and knowledge sharing. Proposedly follow the EHSS model where we have formed a multidisciplinary platform for collaboration across disciplines and professions. The activities initiated and supported by EHSS are one step towards broadening the knowledge and application of HFE in Sweden, and to comprise new arenas of specialization. By participating in the key areas in society such as teaching, standardization, product development and occupational safety and health, the work of EHSS is one piece of the puzzle to improve human activities in the future. The vision is that together, we can improve safety, efficiency and well-being for all

Opting to wear prismatic spectacles was associated with reduced neck pain in dental personnel : A longitudinal cohort study

Background: The aim of this study was to investigate effects on perceived exertion, work ability self-reported neck pain and clinically diagnosed conditions in the neck, of an intervention with prismatic spectacles among dental personnel. Methods: In this cohort study a baseline questionnaire including questions about frequency of neck pain, perceived exertion during work and background information was distributed to dental personnel in municipal dental care units. In connection, personnel from 78 out of 110 dental care units underwent a clinical neck examination and rated their perceived work ability with the single-item question from the Work Ability Index. The study population consisted of 564 participants; 366 in the questionnaire group, 321 in the examination group, whereof 123 participated in both assessments. In total 371 belonged to the intervention group and received individually adjusted prismatic spectacles after the baseline assessments (inclusion based on self-selection) and 193 belonged to the reference group. At the 12-month follow-up the clinical examination was repeated and the same questionnaire with additional questions was completed. Fisher's exact test or the Mann-Whitney U test was used to assess differences between the intervention group and the reference group at baseline. Differences at follow up between the two groups were assessed by means of Linear-by Linear association test for trends. Results: A significant decrease in neck pain (p = 0.047), clinical diagnoses in the neck (p = 0.025), and perceived exertion (p = 0.003) was observed at follow up for the intervention group compared to the reference group. Moreover, for the intervention group a significantly improved self-rated work ability (p = 0.040) was reported. Finally, opting to wear prismatic spectacles during dental work appeared to have a preventive effect on neck pain. Conclusions: Dental personnel opting to wear prismatic spectacles reduced their neck pain significantly more at follow up compared with the reference group. These results are worthwhile testing in a randomised design. The practical implication of this study is that recommendations regarding ergonomics for dental professionals may include the use of prismatic glasses, both as primary and secondary prevention of work-related neck pain. Such glasses should also be tested in other working situations where the work tasks include high visual demands in sustained awkward neck postures