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Purpose This study aimed to evaluate the validity of the Return-to-Work Self-efficacy Questionnaire (RTW-SE) in a Norwegian sample of patients with common mental disorders. The secondary aim was to provide validated cut-off scores for the RTW-SE. Methods Among patients receiving work-focused therapy (N = 626), the RTW-SE was measured pre-and post-treatment, and work status was assessed up to one-year post-treatment. The factor structure, internal consistency and construct validity were assessed. Furthermore, post-treatment cut-off scores were calculated using receiver operating characteristic (ROC) analysis for patients on sick leave at baseline (n = 314) and at the end of treatment (n = 145). The predictive ability of the suggested RTW-SE cut-off scores were investigated longitudinally. Results Exploratory principal component analysis identified a one-factor solution with high internal consistency (0.91). RTW-SE exhibited small to moderate negative correlations with measures of depression and anxiety, and was significantly different between subgroups of patients with different work status, supporting construct validity. Pre- and post-treatment RTW-SE scores significantly predicted full return to work at 3, 6 and 12 months post-treatment. ROC analysis suggested an upper cut-off score of 4.6, associated with full RTW, and lower cut-off score of 3.7, associated with partial RTW. These cut-offs showed acceptable discriminative ability and significant longitudinal predictive ability. Conclusion The RTW-SE possesses good psychometric properties and the suggested cut-off scores have significant predictive ability in a clinical setting.

Simple Summary Migratory bats regularly fly over the North Sea, where the number of offshore wind farms will increase rapidly in the next decades. Information is urgently needed on the timing and the conditions bats can be expected offshore, since windfarms can cause fatalities amongst bats. We therefore collected acoustic data on the presence of bats at four nearshore locations at sea between 2012 and 2016. Modelling the occurrence of Nathusius’ pipistrelle for 480 nights in autumn showed that its migration is strongest in early September, with east-northeasterly tailwinds, low wind speeds, and relatively high temperatures. The species’ migration did not show a strong relationship with other factors, i.e., moon phase, cloud cover, atmospheric pressure, rain, and visibility. Our results provide valuable input to policy-makers to prescribe mitigation measures to reduce bat fatalities in offshore wind farms. Abstract Bats regularly migrate over the North Sea, but information on the environmental conditions when this occurs is scarce. Detailed information is urgently needed on the conditions under which bats can be expected offshore, as the number of offshore windfarms that can cause fatalities amongst bats in the North Sea is increasing rapidly. We performed ultrasonic acoustic monitoring at multiple nearshore locations at sea between 2012 and 2016 for, in total, 480 monitoring nights. We modelled the offshore occurrence of Nathusius’ pipistrelle in autumn as a function of weather conditions, seasonality, and the lunar cycle using a generalized additive mixed model (GAMM). We investigated which covariates are important using backward selection based on a likelihood ratio test. Our model showed that important explanatory variables for the offshore occurrence of Nathusius’ pipistrelle are seasonality (night in year), wind speed, wind direction, and temperature. The species’ migration is strongest in early September, with east-northeasterly tailwinds, wind speeds < 5 m/s, and temperatures > 15 °C. Lunar cycle, cloud cover, atmospheric pressure, atmospheric pressure change, rain, and visibility were excluded during the model selection. These results provide valuable input to reduce bat fatalities in offshore wind farms by taking mitigation measures.

Offshore wind farms' impact on vulnerable species, such as birds and bats through mortality, habitat loss, and barrier effects, is receiving growing attention worldwide. Focus on the effects of wind energy on species is important since the European Union, as well as the international community, strive to halt biodiversity loss through the Nature Conversation Directives and the Sustainable Development Goals. We argue that it is necessary and possible to protect vulnerable species better by quantifying the impact of wind energy on populations, avoiding sensitive areas for species as wind energy development areas, and developing guidelines and measures to mitigate the impact of wind energy. The recognition of existing uncertainties requires more investments in (at least) nationally coordinated monitoring, reporting and adaptive management. This article uncovers barriers in the existing legal framework based on state-of-the-art ecological research. It provides several policy recommendations for improvement, such as a policy guideline, adaptive permitting, and prioritizing (cumulative effects in) environmental impact assessments in wind energy decision-making procedures.

Background Common mental disorders such as depression and anxiety are major contributors to the global burden of disease. Affected individuals suffer reduced quality of life, impaired functioning and reduced capacity to work. Maintaining employment is an important determinant for health and wellbeing, and the economic impact of depression and anxiety is a significant societal expense. Treatments providing effective symptom reduction and helping patients return to work (RTW) would thus have substantial public health benefits. The present study will explore the effectiveness of metacognitive therapy (MCT) and work-focused interventions on reducing symptoms and increasing RTW rates for patients on sick leave due to depression and anxiety. Methods The study is a randomised controlled wait-list trial (RCT; N = 240). The intervention group will receive protocol-based MCT and work-focused interventions immediately after inclusion. The control condition is a wait-list control group. All patients will receive up to 12 weekly sessions. The study context is a Norwegian outpatient clinic part of a national programme aimed at reducing sick leave. The co-primary outcomes are change in RTW and symptoms of depression and anxiety at the end of treatment. In addition to self-report, sick leave will also be collected from national registries from 2 years prior to intervention to 4 years after intervention. Symptoms of depression and anxiety will be collected by self-report at pre- and post-treatment and at 6 and 12 months follow-up after treatment. A cost-effectiveness analysis will use total cost and quality-adjusted life-years as the secondary outcomes. Discussion There is broad consensus on the importance of identifying treatment that effectively reduces depression and anxiety symptoms and aids RTW. This study is an important contribution to the field as it is the first RCT on MCT and work-focused interventions for patients on sick leave due to anxiety and depression. Trial registration ClinicalTrials.gov NCT03301922. Registered on October 4, 2017.

Aerial surveys to estimate the abundance of Harbour Porpoise Phocoena phocoena were conducted on the Dutch Continental Shelf in summer 2019. These surveys followed predetermined track lines in four areas: A - Dogger Bank, B - Offshore, C - Frisian Front & D - Delta. Between 16 July and 4 August the entire Dutch Continental Shelf (DCS) was surveyed. Marine mammals were assessed using line transect distance sampling methods. Density and abundance estimates were calculated. In total, 150 sightings of 189 individual Harbour Porpoises were collected. Porpoise densities varied between 0.54-1.76 animals/km² in the areas A-D. The overall density was 0.66 animals/km². The lowest density (0.46 animals/km²) was recorded in area A – Dogger Bank. The densities in the other areas were in the same order of magnitude, ranging between 0.68-071 animals/km². In summer 2019 the total number of Harbour Porpoises on the Dutch Continental Shelf (areas A-D) was estimated at 38,911 individuals (CI = 20,791-76,822). This estimates falls in the range of abundance estimates since 2010, with a minimum of 25,998 (CI = 13,988 – 53,623 in 2010) and a maximum of 76,773 (CI = 43,414-154,265 in 2014) individuals. The confidence intervals of the abundance estimates overlap, indicating no statistically significant differences between the years. The time series, however, is relatively short to measure trends. These abundance estimates show that up to a fifth of the North Sea population, estimated at 345,000-361,000 individuals, has been present on the Dutch Continental Shelf during the summer surveys in 2010-2019. The results of these aerial surveys will feed into the OSPAR MSFD indicator on abundance and distribution of marine mammals. In total 26 sightings of other marine mammal species than Harbour Porpoises were recorded. These comprised 22 sightings of seals (Grey Seal Halichoerus grypus and Harbour Seal Phoca vitulina). The majority of the seals was observed in coastal waters off the Wadden Isles. Three single Minke Whales Balaenoptera acutorostrata were seen (feeding) in area A – Dogger Bank and B – Offshore, with another one sighted off effort in the same area. One sighting of a pod of two White-beaked Dolphins Lagenorhynchus albirostris was made in area B – Offshore. This research is part of the BO-project ‘monitoring bruinvis’.

Het Friese Front en de Bruine Bank zijn twee nieuwe Vogelrichtlijngebieden in de Noordzee. Het Friese Front is aangewezen voor de Zeekoet. De Bruine Bank wordt waarschijnlijk aangewezen voor Zeekoet en Alk. Om te bepalen of de instandhoudingsdoelstellingen voor deze soorten worden gehaald, moeten de aantallen van deze soorten gemonitord worden. Monitoring van zeevogels in het Nederlandse deel van de Noordzee vindt plaats met behulp van MWTL-vliegtuigtellingen. Alken en Zeekoeten kunnen vanuit de lucht echter lastig van elkaar te onderscheiden zijn. Vanaf schepen is de herkenning eenvoudiger. Het onderhavige BO-project 'scheepstellingen zeevogels' dat in 2016-2019 loopt, heeft tot doel inzicht te geven in de aantallen van Alken en Zeekoeten in beide gebieden enerzijds, en anderzijds in de veranderingen in aantalsverhouding tussen beide soorten gedurende het jaar om de MWTL-vliegtuigtellingen te kunnen calibreren. In 2018 zijn twee scheepssurveys op het Friese Front uitgevoerd (24-28 jul, 25-28 nov). De julisurvey was succesvol, terwijl de novembersurvey door slechte weersomstandigheden afgebroken moest worden. Tijdens de julisurvey werden 13650 individuen verdeeld over 25 verschillende vogelsoorten op het Friese Front geteld. Zeekoet (n = 6127), Kleine Mantelmeeuw (n = 2680), Drieteenmeeuw (n = 1544), Noordse Stern/Visdief (n = 1176) en Jan-van-Gent (n = 1175) domineerden de telling. Daarnaast werden 143 individuen verdeeld over drie soorten zeezoogdieren (Dwergvinvis, Bruinvis en Grijze Zeehond) geregistreerd. In november werden op het Friese Front 1864 individuen verdeeld over 15 verschillende vogelsoorten geteld. Zeekoet (n = 717), Alk (n = 697) en Drieteenmeeuw (n = 190) waren de dominante soorten. Daarnaast werden vijf Bruinvissen gezien. Tijdens beide surveys was Zeekoet de talrijkste soort. In juli werden de hoogste aantallen Zeekoeten op het Friese Front geteld, terwijl Alken hier ontbraken. In november waren de aantallen Zeekoeten lager, maar waren Alken talrijker. De verhouding Alk:Zeekoet was in november 1:1. Behalve van alkachtigen werden aanvullende gegevens verzameld over de aantallen van potentieel kwalificerende N2000-soorten Grote Mantelmeeuw (met name nov) en Kleine Mantelmeeuw (met name jul). De aantallen van de potentieel kwalificerende N2000-soort Grote Jager waren tijdens alle 2018-surveys laag. De resultaten van de surveys in 2016 en 2017 zijn gepubliceerd in Geelhoed & Leopold (2017) en Geelhoed et al (2018). Dit rapport geeft een beknopt overzicht van de resultaten van de surveys in 2018. Eind 2019 worden de resultaten van alle surveys nader uitgewerkt en gepresenteerd in een eindrapportage.

Numerous land-based studies have shown that wind farms can have a significant negative effect on bat populations due to collisions and barotrauma. Since a few years it is also known that bats migrate regularly over the North Sea. In order to reduce uncertainties about possible impacts of the development of the offshore wind sector Rijkswaterstaat commissioned a follow-up offshore bat monitoring project as part of the WOZEP programme (Offshore Wind Ecological Programme). The monitoring will continue until at least 2019 and possibly throughout 2020. After that, the final report will be compiled, which will include a spatiotemporal analysis of the offshore occurrence of bats in all previous monitoring years. This report provides an overview of the monitoring effort and monitoring results in 2017 & 2018.Currently there are 14 monitoring locations where acoustic bat monitoring is executed, of which seven are oil & gas rigs, five are offshore high voltage stations of offshore wind farms and two are measurement platforms (Lichteiland Goeree and Europlatform). Since 2017 a new type of batdetector (Avisoft) is applied. In order to assess differences between the previously used batdetector (Batcorder) we monitored simultaneously with both detectors at three monitoring locations.The monitoring results in 2017 and 2018 show the same general pattern of occurrence as in previous years with Nathusius pipistrelle being the most common species, and Common pipistrelles and ‘Nyctaloids’ much more scarce.Furthermore the differences in performance are discussed between the currently used Avisoft detector and the previously used Batcorder. It appears that a correction should be applied in order to make measurements comparable between the two detectors, and the value of this correction factor depends on the time interval used in the analysis. At this moment the precision of the correction factor is estimated at 1.17 for 10 minute time intervals. In order to improve the precision to 1.1 simultaneous monitoring by both detectors should continue at least two monitoring years.Finally it is shown that there are obvious differences in occurrence amongst monitoring locations, between spring and autumn, as well as amongst years. However, a clear spatial pattern (e.g. from south to north or from east to west) does not emerge from this (preliminary) analysis. This should be investigated in a statistical model at the end of this project when all data of the entire monitoring period will be available as well.

With a foreseen increase in maritime activities, and driven by new policies and conventions aiming at sustainable management of the marine ecosystem, spatial management at sea is of growing importance. Spatial management should ensure that the collective pressures caused by anthropogenic activities on the marine ecosystem are kept within acceptable levels. A multitude of approaches to environmental assessment are available to provide insight for sustainable management, and there is a need for a harmonized and integrated environmental assessment approach that can be used for different purposes and variable levels of detail. This article first provides an overview of the main types of environmental assessments: "environmental impact assessment" (EIA), "strategic environmental assessment" (SEA), "cumulative effect assessment" (CEA), and "environmental (or ecological) risk assessment" (ERA). Addressing the need for a conceptual "umbrella" for the fragmented approaches, a generic framework for environmental assessment is proposed: cumulative effects of offshore activities (CUMULEO). CUMULEO builds on the principle that activities cause pressures that may lead to adverse effects on the ecosystem. Basic elements and variables are defined that can be used consistently throughout sequential decision-making levels and diverse methodological implementations. This enables environmental assessment to start at a high strategic level (i.e., plan and/or program level), resulting in early environmental awareness and subsequently more informed, efficient, and focused project-level assessments, which has clear benefits for both industry and government. Its main strengths are simplicity, transparency, flexibility (allowing the use of both qualitative and quantitative data), and visualization, making it a powerful framework to support discussions with experts, stakeholders, and policymakers. Integr Environ Assess Manag 2016;12:632-642. © 2015 SETAC.

De cumulatieve impact van energie-infrastructuur kan een belangrijke rol spelen bij de populatieontwikkeling van kwetsbare soorten door sterfte en habitatverlies als gevolg van aanvaringen met die energie-infrastructuur of het verstorende effect van dergelijke infrastructuur. In dit rapport wordt een zo actueel en volledig mogelijk overzicht gegeven van de staat van kennis en de relatieve kwetsbaarheid van vogels, vleermuizen, zeezoogdieren en vissen in relatie tot de impact van windturbines, hoogspanningslijn en, waterkrachtcentrales en zonnepaneelvelden. Voor deze soortgroepen en energie-infrastructuur worden de kwetsbare soorten gerangschikt op basis van hun kwetsbaarheid en wordt inzichtelijk gemaakt waar de verspreiding van de kwetsbaarste soorten overlapt met de energie-infrastructuur. We evalueren hoe de cumulatieve impact van energie-infrastructuur op de soortgroepen gekwantificeerd kan worden nu en in de toekomst, en hoe die impact zich verhoudt tot andere antropogene drukfactoren voor de kwetsbaarste soorten. We bespreken mitigatie- en compensatiemaatregelen die in potentie kunnen voorkomen dat Nederlandse populaties van soorten afnemen als gevolg van de huidige en toekomstige energie-infrastructuur op zee en op land. Tot slot worden suggesties gedaan voor het opvullen van de belangrijkste kennishiaten en oplossingsrichtingen die het mogelijk maken de effecten op kwetsbare soorten bij de verdere groei van energie-infrastructuur op land en op zee te minimaliseren.

To close the knowledge gap described above, or better said in order to make a start to overcome this crucial lack of insight into (sub)population sizes, RWS commissioned the Bats_1 study as part of the Wind op Zee Ecological Programma (Wozep; in English: Wind at Sea Ecological Programme), a multi-annual research programme initiated in view of the realisation of new offshore wind farms under the SER agreement (2013). Aim of the Bat_1 desk study is to estimate the extent to which (sub)populations of Nathusius’ Pipistrelle and possibly other relevant bat species, expressed in terms of numbers of individuals, use migration routes across the southern North Sea (SNS)1. This information is of great importance to be able to make better estimates of what the Potential Biological Removal (PBR) values are of Nathusius’ Pipistrelle and possibly other bat species, knowing that these values depend on the size of the (sub)populations to be considered.

Aquaculture within offshore wind farms has been identified as one of the many possibilities of smart use of marine space, leading to opportunities for innovative entrepreneurship. Offshore areas potentially pose less conflict with co-users than onshore. At the same time, offshore areas and offshore constructions are prone to high technical risks through mechanical force, corrosion, and biofouling. The expected lifetime of an offshore structure is to a great extent determined by the risk of failures. This chapter elaborates on logistical challenges that the offshore industry faces. Operation and maintenance (O&M) activities typically represent a big part of the total costs (e.g. 25–30% of the total lifecycle costs for offshore wind farms). The offshore wind energy sector is considered an industry with promising features for the public and private sector. Large wind farms farther off the coast pose high expectations because of higher average wind speeds and hence greater wind energy yield (in terms of megawatts per capital). These conditions entail additional challenges in logistics, though. One of the main hurdles that hinders use of offshore wind energy is the high cost for O&M. The offshore wind industry will have to solve these problems in order to achieve substantial cost reduction - alone or jointly with other (potential) users. It is precisely the logistical problems around O&M where most likely synergy benefits of multi-use platforms (MUPs) can be achieved. The offshore wind energy industry is eagerly looking for technical innovations. Until now they mostly sought the solutions in their own circles. If the combination of offshore wind energy and offshore aquaculture proves to be feasible and profitable in practice, there may be an additional possibility to reduce the O&M costs by synergy effects of the combined operations. Logistic waiting times, for example, can result in substantial revenue losses, whereas timely spare-parts supply or sufficient repair capacity (technicians) to shorten the logistic delay times are beneficial. A recent study suggests that a cost reduction of 10% is feasible, if the offshore wind and offshore aquaculture sectors are combined in order to coordinate and share O&M together. The presented asset management control model proves useful in testing the innovative, interdisciplinary multi-use concepts, simulating return rates under different assumptions, thus making the approach more concrete and robust.

This study, as part of the Wozep-project Behaviour and Collision Risk of Bats (Bats_2), investigates how bat behaviour can be studied near offshore wind turbines. To find out whether it is wise to continue and further develop behavioural research at wind turbines in the context of the Wozep programme, we first conducted a feasibility study on land.

Divergent selection stemming from environmental variation may induce local adaptation and ecological speciation whereas gene flow might have a homogenizing effect. Gene flow among populations using different environments can be reduced by geographical distance (isolation-by-distance) or by divergent selection stemming from resource use (isolation-by-ecology). We tested for and encountered phenotypic and genetic divergence among Spanish crossbills utilizing different species of co-occurring pine trees as their food resource. Morphological, vocal and mtDNA divergence were not correlated with geographical distance, but they were correlated with differences in resource use. Resource diversity has now been found to repeatedly predict crossbill diversity. However, when resource use is not 100% differentiated, additional characters (morphological, vocal, genetic) must be used to uncover and validate hidden population structure. In general, this confirms that ecology drives adaptive divergence and limits neutral gene flow as the first steps towards ecological speciation, unprevented by a high potential for gene flow.

Because of the costs to both the organization and the individual, it is important that employees who are sick-listed with mental health problems are facilitated in their return to work (RTW). In order to provide adequate interventions, it is necessary to obtain a better understanding of the RTW process of people with mental health problems. Work-related self-efficacy (SE) might play a key role within this process. This paper describes the development and validation of the return-to-work self-efficacy' scale (RTW-SE) for employees with mental health problems. Three Dutch samples of sick-listed employees were used to validate the 11-item instrument (N=2214). Based on the factor structure and reliability results, RTW-SE was conceptualized as a unitary construct. The associations with general SE, locus of control, coping, physical workload and mental health problems support the construct validity of this scale. Most importantly, RTW-SE proved to be a robust predictor of actual return to work within three months. The encouraging preliminary psychometric properties of the scale make it a potentially valuable tool in research and in clinical practice and occupational health care settings, both before and after employees have returned to work. © 2010 Taylor & Francis. ispartof: Work and Stress vol:24 issue:4 pages:359-375 status: published

This study examined the associations between workaholism and perceived health (exhaustion, physical complaints, and feelings of professional efficacy) in a sample of 477 Dutch self-employed workers. We defined workaholism as having two components: (1) spending many hours on one's work, and (2) the inability to detach from work. We expected that both workaholism components would be related to ill health. ANOVA and regression analyses revealed that this reasoning was confirmed for one component (inability to detach from work), whereas the other component (working long hours) was unrelated to the outcome variables. In order to increase understanding of these findings, we suggest that more theoretical work be conducted on the mechanisms linking workaholism to its presumed antecedents and consequences.

We investigated the effectiveness of cognitive behavioural therapy (CBT) and a combined intervention of workplace- and individual-focused techniques among self-employed people on sick leave owing to work-related psychological complaints (such as anxiety, depression, and burnout). Both interventions were based on CBT; however, one was conducted by psychotherapists and involved extensive CBT, while the other was delivered by "labour experts" and consisted of a brief CBT-derived intervention combined with both individual-focused and workplace interventions. One hundred and twenty-two self-employed people who had applied for sickness benefit from an insurance company enrolled in a randomized controlled design. These individuals were assessed before the intervention and then at 4 months and 10 months after the onset of the intervention. The outcome was assessed based on duration of sick leave until partial and full return to work and on psychological complaints. Significant effects on partial and full return were found in favour of the combined intervention: partial return occurred 17 and 30 days earlier in this group than in the CBT group and the control group, respectively. For full return to work, the difference was approximately 200 days. A decrease in psychological complaints was present in each condition but we found no significant interaction effects. The results suggest that work resumption should be addressed earlier in individuals receiving CBT. This insight is of value for the (scarce) literature concerning interventions for individuals who are on sick leave owing to work-related psychological complaints. © 2006 Taylor & Francis.

Contains fulltext : 136495.pdf (Publisher’s version ) (Open Access) OBJECTIVE: The purpose of the present study was to explore various stakeholder perspectives regarding factors that impede return-to-work (RTW) after long-term sickness absence related to major depressive disorder (MDD). METHODS: Concept mapping was used to explore employees', supervisors' and occupational physicians' perspectives on these impeding factors. RESULTS: Nine perceived themes, grouped in three meta-clusters were found that might impede RTW: Person, (personality / coping problems, symptoms of depression and comorbid (health) problems, employee feels misunderstood, and resuming work too soon), Work (troublesome work situation, too little support at work, and too little guidance at work) and Healthcare (insufficient mental healthcare and insufficient care from occupational physician). All stakeholders regarded personality/coping problems and symptoms of depression as the most important impeding theme. In addition, supervisors emphasized the importance of mental healthcare underestimating the importance of the work environment, while occupational physicians stressed the importance of the lack of safety and support in the work environment. CONCLUSIONS: In addition to the reduction of symptoms, more attention is needed on coping with depressive symptoms and personality problems in the work environment support in the work environment and for RTW in mental healthcare, to prevent long term sickness absence.

The aim of this study was to compare the effectiveness of two individual-level psychotherapy interventions: (a) treatment as usual consisting of cognitive-behavioral therapy (CBT) and (b) work-focused CBT (W-CBT) that integrated work aspects early into the treatment. Both interventions were carried out by psychotherapists with employees on sick leave because of common mental disorders (depression, anxiety, or adjustment disorder). In a quasi-experimental design, 12-month follow-up data of 168 employees were collected. The CBT group consisted of 79 clients, the W-CBT group of 89. Outcome measures were duration until return to work (RTW), mental health problems, and costs to the employer. We found significant effects on duration until RTW in favor of the W-CBT group: full RTW occurred 65 days earlier. Partial RTW occurred 12 days earlier. A significant decrease in mental health problems was equally present in both conditions. The average financial advantage for the employer of an employee in the W-CBT group was estimated at $5,275 U.S. dollars compared with the CBT group. These results show that through focusing more and earlier on work-related aspects and RTW, functional recovery in work can be substantially speeded up within a regular psychotherapeutic setting. This result was achieved without negative side effects on psychological complaints over the course of 1 year. Integrating work-related aspects into CBT is, therefore, a fruitful approach with benefits for employees and employers alike. ispartof: Journal of Occupational Health Psychology vol:17 issue:2 pages:220-234 ispartof: location:United States status: published

Divergent selection stemming from environmental variation may induce local adaptation and ecological speciation whereas gene flow might have a homogenizing effect. Gene flow among populations using different environments can be reduced by geographical distance (isolation-by-distance) or by divergent selection stemming from resource use (isolation-by-ecology). We tested for and encountered phenotypic and genetic divergence among Spanish crossbills utilizing different species of co-occurring pine trees as their food resource. Morphological, vocal and mtDNA divergence were not correlated with geographical distance, but they were correlated with differences in resource use. Resource diversity has now been found to repeatedly predict crossbill diversity. However, when resource use is not 100% differentiated, additional characters (morphological, vocal, genetic) must be used to uncover and validate hidden population structure. In general, this confirms that ecology drives adaptive divergence and limits neutral gene flow as the first steps towards ecological speciation, unprevented by a high potential for gene flow.

Background Depression is associated with negative work outcomes such as reduced work participation (WP) (e.g., sick leave duration, work status) and work functioning (WF) (e.g., loss of productivity, work limitations). For the development of evidence-based interventions to improve these work outcomes, factors predicting WP and WF have to be identified. Methods This paper presents a systematic literature review of studies identifying factors associated with WP and WF of currently depressed workers. Results A total of 30 studies were found that addressed factors associated with WP (N = 19) or WF (N = 11). For both outcomes, studies reported most often on the relationship with disorder-related factors, whereas personal factors and work-related factors were less frequently addressed. For WP, the following relationships were supported: strong evidence was found for the association between a long duration of the depressive episode and work disability. Moderate evidence was found for the associations between more severe types of depressive disorder, presence of co-morbid mental or physical disorders, older age, a history of previous sick leave, and work disability. For WF, severe depressive symptoms were associated with work limitations, and clinical improvement was related to work productivity (moderate evidence). Due to the cross-sectional nature of about half of the studies, only few true prospective associations could be identified. Conclusion Our study identifies gaps in knowledge regarding factors predictive of WP and WF in depressed workers and can be used for the design of future research and evidence-based interventions. We recommend undertaking more longitudinal studies to identify modifiable factors predictive of WP and WF, especially work-related and personal factors. Electronic supplementary material The online version of this article (doi:10.1007/s10926-009-9224-x) contains supplementary material, which is available to authorized users.

Dit artikel beschrijft de belangrijkste uitkomsten van een empirisch onderzoek naar de problematiek van "moeilijk objectiveerbare gezondheidsklachten" in de bedrijfs- en verzekeringsgeneeskundige praktijk. Een belangrijk doel van dit onderzoek was de aard en omvang van deze problematiek in kaart te brengen. Hiervoor werd een vragenlijstonderzoek verricht onder 18 bedrijfs- en 19 verzekeringsartsen, waarbij ruim 1200 korte casussen zijn beschreven. De uitkomsten duiden erop dat de problematiek van moeilijk objectiveerbare klachten in de bedrijfs- en verzekeringsgeneeskundige praktijk aanzienlijk is. Het gaat hierbij met name om pijnklachten en energetische en affectieve klachten. Moeilijk objectiveerbare gezondheidsklachten blijken voorts gepaard te gaan met problemen met betrekking tot het vaststellen van de gepaste begeleiding en het beoordeling van beperkingen en arbeidsmogelijkheden. Verder blijkt dat een relatief groot deel van de artsen behoefte heeft aan aanvullende instrumenten, kennis en vaardigheden met betrekking tot moeilijk objectiveerbare gezondheidsklachten. De auteurs pleiten voor aanvullend beleid of de ontwikkeling van een protocol / checklist, om de problematiek van moeilijk objectiveerbare gezondheidsklachten te verminderen.