Grid Cell Hexagonal Patterns Formed by Fast Self-Organized Learning within Entorhinal Cortex

Grid cells in the dorsal segment of the medial entorhinal cortex (dMEC) show remarkable hexagonal activity patterns, at multiple spatial scales, during spatial navigation. How these hexagonal patterns arise has excited intense interest. It has previously been shown how a selforganizing map can convert firing patterns across entorhinal grid cells into hippocampal place cells that are capable of representing much larger spatial scales. Can grid cell firing fields also arise during navigation through learning within a self-organizing map? A neural model is proposed that converts path integration signals into hexagonal grid cell patterns of multiple scales. This GRID model creates only grid cell patterns with the observed hexagonal structure, predicts how these hexagonal patterns can be learned from experience, and can process biologically plausible neural input and output signals during navigation. These results support a unified computational framework for explaining how entorhinal-hippocampal interactions support spatial navigation.CELEST, a National Science Foundation Science of Learning Center (SBE-0354378); SyNAPSE program of Defense Advanced Research Projects Agency (HR00ll-09-3-0001, HR0011-09-C-0011

Exploring the return-to-work process for workers partially returned to work and partially on long-term sick leave due to common mental disorders:a qualitative study

Purpose. We conducted a qualitative study into the return-to-work process of workers partially on sick leave due to common mental disorders. Our objectives were to describe the barriers to a full return to work, solutions, communicating to the working environment and the aim of a full return to work, all as perceived by the workers. Method. Workers who had partially returned to work and were partially on long-term sick leave due to a stress-related, anxiety or depressive disorder were eligible for this study. Fourteen workers were interviewed and the interviews were transcribed verbatim and coded. Results. The perceived main barriers were: inability to set limits, recognise exhaustion and to control cognitions and behaviour such as perfectionism. A general pattern in the process was that all workers perceived barriers to a full return to work; most workers were able to mention solutions; all workers aimed for a full return to work, and after some time all workers were met with sufficient understanding and social support from their supervisor and health care professional. However, hardly any worker intended to implement or utilise the solutions at the workplace, except the structural adaptations of the work demands. Conclusions. The pattern we found suggests a critical intention-behaviour gap between solutions and intentions for a full return to work and its implementation at work. This implies that we should develop new interventions that focus on helping workers and their environment to bridge this gap

Surface roughness effects on the solar reflectance of cool asphalt shingles

We analyze the solar reflectance of asphalt roofing shingles that are covered with pigmented mineral roofing granules. The reflecting surface is rough, with a total area approximately twice the nominal area. We introduce a simple analytical model that relates the 'micro-reflectance' of a small surface region to the 'macro-reflectance' of the shingle. This model uses a mean field approximation to account for multiple scattering effects. The model is then used to compute the reflectance of shingles with a mixture of different colored granules, when the reflectances of the corresponding mono-color shingles are known. Simple linear averaging works well, with small corrections to linear averaging derived for highly reflective materials. Reflective base granules and reflective surface coatings aid achievement of high solar reflectance. Other factors that influence the solar reflectance are the size distribution of the granules, coverage of the asphalt substrate, and orientation of the granules as affected by rollers during fabrication

Occurrence of Fusarium Mycotoxins and Their Modified Forms in Forage Maize Cultivars

Forage maize is often infected by mycotoxin-producing Fusarium fungi during plant growth, which represent a serious health risk to exposed animals. Deoxynivalenol (DON) and zearalenone (ZEN) are among the most important Fusarium mycotoxins, but little is known about the occurrence of their modified forms in forage maize. To assess the mycotoxin contamination in Northern Germany, 120 natural contaminated forage maize samples of four cultivars from several locations were analysed by liquid chromatography-high resolution mass spectrometry (LC-HRMS) for DON and ZEN and their modified forms deoxynivalenol-3-glucoside (DON3G), the sum of 3- and 15-acetyl-deoxynivalenol (3+15-AcDON), α- and β-zearalenol (α-ZEL, β-ZEL). DON and ZEN occurred with high incidences (100 and 96%) and a wide range of concentrations, reaching levels up to 10,972 and 3910 µg/kg, respectively. Almost half of the samples (46%) exceeded the guidance value in complementary and complete feeding stuffs for ZEN (500 µg/kg), and 9% for DON (5000 µg/kg). The DON related mycotoxins DON3G and 3+15-AcDON were also present in almost all samples (100 and 97%) with amounts of up to 3038 and 2237 µg/kg and a wide range of concentrations. For the ZEN metabolites α- and β-ZEL lower incidences were detected (59 and 32%) with concentrations of up to 423 and 203 µg/kg, respectively. Forage maize samples were contaminated with at least three co-occurring mycotoxins, whereby 95% of all samples contained four or more mycotoxins with DON, DON3G, 3+15-AcDON, and ZEN co-occurring in 93%, together with α-ZEL in 57% of all samples. Positive correlations were established between concentrations of the co-occurring mycotoxins, especially between DON and its modified forms. Averaged over all samples, ratios of DON3G/DON and 3+15-AcDON/DON were similar, 20.2 and 20.5 mol%; cultivar-specific mean ratios ranged from 14.6 to 24.3 mol% and 15.8 to 24.0 mol%, respectively. In total, 40.7 mol% of the measured DON concentration was present in the modified forms DON3G and 3+15-AcDON. The α-ZEL/ZEN ratio was 6.2 mol%, ranging from 5.2 to 8.6 mol% between cultivars. These results demonstrate that modified mycotoxins contribute substantially to the overall mycotoxin contamination in forage maize. To avoid a considerable underestimation, it is necessary to analyse modified mycotoxins in future mycotoxin monitoring programs together with their parent forms

Effect of a multidisciplinary stress treatment programme on the return to work rate for persons with work-related stress. A non-randomized controlled study from a stress clinic

<p>Abstract</p> <p>Background</p> <p>In recent years an increasing number of patients have been referred to the medical sector with stress symptoms. Moreover, these conditions imply increased sickness absence. This indicates a need for treatment programmes in general medical practice. The aim of this study was to test the effect of a multidisciplinary stress treatment programme on the return to work (RTW) rate in persons with work-related stress and establish predictive factors for this outcome.</p> <p>Methods</p> <p>During a two-year period 63 out of 73 referrals to the Stress Clinic (a section of a Clinic of Occupational Medicine) completed a stress treatment programme consisted of the following:</p> <p>1) Identification of relevant stressors. 2. Changing the coping strategies of the participants. 3. Evaluating/changes in participant workload and tasks. 4. Relaxation techniques. 5. Physical exercise. 6. Psychiatric evaluation when indicated by depression test score.</p> <p>On average each patient attended six one-hour sessions over the course of four months.</p> <p>A group of 34 employees referred to the Clinic of Occupational Medicine by their general practitioners served as a control group. Each participant had a one-hour consultation at baseline and after four months. A specialist in occupational medicine carried out all sessions.</p> <p>Return To Work (RTW), defined as having a job and not being on sick leave at the census, was used as outcome measure four months after baseline, and after one and two years.</p> <p>Results</p> <p>The level of sick leave in the stress treatment group dropped from 52% to 16% during the first four months of follow-up and remained stable. In the control group, the reduction in sick leave was significantly smaller, ranging from 48% at baseline to 27% after four months and 24% after one year. No statistically significant difference between the two groups was observed after one and two years. Age below 50 years and being a manager increased the odds ratio for RTW after one and two years, while gender and depression had no predictive value.</p> <p>Conclusions</p> <p>The stress treatment programme showed a significant effect on the return to work rate. The stress treatment programme seems feasible for general practitioners.</p> <p>Trial Registration</p> <p>ISRCTN04354658</p

A Cluster-Randomised Trial Evaluating an Intervention for Patients with Stress-Related Mental Disorders and Sick Leave in Primary Care

Objective: Mental health problems often affect functioning to such an extent that they result in sick leave. The worldwide reported prevalence of mental health problems in the working population is 10%–18%. In developed countries, mental health problems are one of the main grounds for receiving disability benefits. In up to 90% of cases the cause is stress-related, and health-care utilisation is mainly restricted to primary care. The aim of this study was to assess the effectiveness of our Minimal Intervention for Stress-related mental disorders with Sick leave (MISS) in primary care, which is intended to reduce sick leave and prevent chronicity of symptoms. Design: Cluster-randomised controlled educational trial. Setting: Primary health-care practices in the Amsterdam area, The Netherlands. Participants: A total of 433 patients (MISS n ¼ 227, usual care [UC] n ¼ 206) with sick leave and self-reported elevated level of distress. Interventions: Forty-six primary care physicians were randomised to either receive training in the MISS or to provide UC. Eligible patients were screened by mail. Outcome Measures: The primary outcome measure was duration of sick leave until lasting full return to work. The secondary outcomes were levels of self-reported distress, depression, anxiety, and somatisation. Results: No superior effect of the MISS was found on duration of sick leave (hazard ratio 1.06, 95% confidence interval 0.87–1.29) nor on severity of self-reported symptoms. Conclusions: We found no evidence that the MISS is more effective than UC in our study sample of distressed patients. Continuing research should focus on the potential beneficial effects of the MISS; we need to investigate which elements of the intervention might be useful and which elements should be adjusted to make the MISS effective

A Prospective Study of Return to Work Across Health Conditions: Perceived Work Attitude, Self-efficacy and Perceived Social Support

Background The aim of the present study was to conduct subgroup-analyses in a prospective cohort of workers on long-term sickness absence to investigate whether associations between perceived work attitude, self-efficacy and perceived social support and time to RTW differ across different health conditions. Methods The study was based on a sample of 926 workers on sickness absence (6–12 weeks). The participants filled out a baseline questionnaire and were subsequently followed until the tenth month after listing sick. Perceived work attitude was measured with a Dutch language version of the Work Involvement Scale. Perceived social support was measured with a self-constructed standardized scale reflecting a person’s perception of social support regarding RTW. Self-efficacy was measured with the standardised Dutch version of the General self-efficacy scale, assessing the subjects’ expectations of their general capacities. The sample was divided into three subgroups: musculoskeletal health conditions, other physical health conditions and mental health conditions. Anova analyses and Cox proportional hazards regression analyses were used to identify differences in association between the three factors and the time to RTW between different subgroups. Results The associations between the perceived work attitude, self-efficacy and perceived social support and the time to RTW vary across different health condition subgroups, not only with regard to the strength of the association but also for the type of factor. In the multivariate model, hazard ratios (HRs) of 1.33 (95% CI 1.01–1.75) in the musculoskeletal subgroup, and 1.26 (95% CI 0.89–1.78) in the other physical subgroup were found in perceived work attitude. With regard to perceived social support HRs of 1.39 (95% CI 1.12–1.99) respectively 1.51 (1.05–2.17) in the same subgroups were found. Only self-efficacy remained in the multivariate model in all subgroups with HRs of 1.49 (95% CI 1.12–1.99) in the musculoskeletal subgroup, 1.53 (95% CI 1.07–2.18) in the other physical subgroup and 1.60 (1.07–2.40) in the mental subgroup. Conclusions The results of this study show that perceived work attitude, self-efficacy and perceived social support are relevant predictors with regard to the time to RTW in all types of health conditions, but that important differences are observed in type of factor and strengths of the relationships between physical and mental health conditions

A global database for metacommunity ecology, integrating species, traits, environment and space

The use of functional information in the form of species traits plays an important role in explaining biodiversity patterns and responses to environmental changes. Although relationships between species composition, their traits, and the environment have been extensively studied on a case-by-case basis, results are variable, and it remains unclear how generalizable these relationships are across ecosystems, taxa and spatial scales. To address this gap, we collated 80 datasets from trait-based studies into a global database for metaCommunity Ecology: Species, Traits, Environment and Space; “CESTES”. Each dataset includes four matrices: species community abundances or presences/absences across multiple sites, species trait information, environmental variables and spatial coordinates of the sampling sites. The CESTES database is a live database: it will be maintained and expanded in the future as new datasets become available. By its harmonized structure, and the diversity of ecosystem types, taxonomic groups, and spatial scales it covers, the CESTES database provides an important opportunity for synthetic trait-based research in community ecology

TGF-β promotes microtube formation in glioblastoma through Thrombospondin 1

International audienceAbstract Background Microtubes (MTs), cytoplasmic extensions of glioma cells, are important cell communication structures promoting invasion and treatment resistance through network formation. MTs are abundant in chemoresistant gliomas, in particular, glioblastomas (GBMs), while they are uncommon in chemosensitive IDH-mutant and 1p/19q co-deleted oligodendrogliomas. The aim of this study was to identify potential signaling pathways involved in MT formation. Methods Bioinformatics analysis of TCGA was performed to analyze differences between GBM and oligodendroglioma. Patient-derived GBM stem cell lines were used to investigate MT formation under transforming growth factor-beta (TGF-β) stimulation and inhibition in vitro and in vivo in an orthotopic xenograft model. RNA sequencing and proteomics were performed to detect commonalities and differences between GBM cell lines stimulated with TGF-β. Results Analysis of TCGA data showed that the TGF-β pathway is highly activated in GBMs compared to oligodendroglial tumors. We demonstrated that TGF-β1 stimulation of GBM cell lines promotes enhanced MT formation and communication via calcium signaling. Inhibition of the TGF-β pathway significantly reduced MT formation and its associated invasion in vitro and in vivo. Downstream of TGF-β, we identified thrombospondin 1 (TSP1) as a potential mediator of MT formation in GBM through SMAD activation. TSP1 was upregulated upon TGF-β stimulation and enhanced MT formation, which was inhibited by TSP1 shRNAs in vitro and in vivo. Conclusion TGF-β and its downstream mediator TSP1 are important mediators of the MT network in GBM and blocking this pathway could potentially help to break the complex MT-driven invasion/resistance network