Measuring nutrient fluxes across the sediment-water interface using benthic chambers

11 páginas, 8 figuras, 2 tablas.This paper presents a simple model to determine the benthic fluxes of matter across the sediment-water interface when a benthic chamber is used. The model is based on accepting that the limiting step for the overall rate of transfer while the chamber is in position is the diffusion through the diffusive boundary layer (DBL) overlying the sediment, and it assumes that this rate is necessarily affected by the procedure employed to measure the flux. Alteration of the benthic fluxes due to the action of macrofauna is included in the model and, operatively, is expressed in terms of a reduction in the thickness of the DBL between the sediment and the water. If the diffusive fluxes are determined simultaneously with the benthic chamber experiments, a value can be estimated for the thickness of the 'stagnant film'. Owing to the assumptions made and to the micro-heterogeneities of the sediment, this thickness can be considered to have both an operative and a statistical meaning, with respect to the entire surface area covered by the chamber. The values calculated in the Bay of Cádiz (SW Spain) vary between 0.36 and 0.71 mm, which are in agreement with measurements of this film made by different techniques in other littoral ecosystems. However, the values of the in situ fluxes estimated using this model and by other established procedures described in the literature can differ by more than 50%, for the same experiment, in strongly irrigated zones.The work was supported by the Consejo Superior de Investigaciones Científicas (CSIC) through research grant 630/070-1988.Peer reviewe

Quality of life and life circumstances in German myasthenia gravis patients

<p>Abstract</p> <p>Background</p> <p>Myasthenia gravis (MG) is a chronic neuromuscular disease. Advances in medical therapy have continuously increased the life expectancy of MG patients, without definitively curing the disease. To analyze life circumstances and quality of life (QoL), a large German MG cohort was investigated.</p> <p>Methods and Sample</p> <p>In cooperation with the German Myasthenia Association, 2,150 patients with confirmed MG were asked to respond to a mailed questionnaire. The standardized questions related to demographic data, impairments, therapeutic course, use of complementary therapies, illness-related costs, and quality of life (SF-36). In total, 1,518 patients participated, yielding a response rate of 70.6%. The average age was 56.7 years, and the proportion of females 58.6%.</p> <p>Results</p> <p>Despite receiving recommended therapy, many patients still suffered from MG-related impairments. In particular, mobility and mental well-being were reduced; moreover, quality of life was markedly reduced. Stepwise linear regression analysis revealed illness stability, impairments, mental conditions, comorbid diseases, and employment to be determinants of QoL.</p> <p>Conclusion</p> <p>Results indicate that despite prolonged life expectancy among MG patients, health-related quality of life is low. This outcome resulted mainly from impaired mobility and depression. Physical and mental well-being might be improved by additional therapy options. Additionally, health care resources could be used more efficiently in these patients.</p

Spirituality in general practice

In a pluraIist and secular society, as well as in a medical world which is becoming increasingly evidence-based, making a case for consideration of spirituaIity in general practice may seem futile and irrelevant. Notwithstanding such an apparent paradoxical proposal, developments occurring in other specialties 1 as well as in general practice abroad reveal that it is high time that this theme is addressed academically and impIications appIied in local practice.peer-reviewe

Study of exclusive one-pion and one-eta production using hadron and dielectron channels in pp reactions at kinetic beam energies of 1.25 GeV and 2.2 GeV with HADES

We present measurements of exclusive ensuremathπ+,0 and η production in pp reactions at 1.25GeV and 2.2GeV beam kinetic energy in hadron and dielectron channels. In the case of π+ and π0 , high-statistics invariant-mass and angular distributions are obtained within the HADES acceptance as well as acceptance-corrected distributions, which are compared to a resonance model. The sensitivity of the data to the yield and production angular distribution of Δ (1232) and higher-lying baryon resonances is shown, and an improved parameterization is proposed. The extracted cross-sections are of special interest in the case of pp → pp η , since controversial data exist at 2.0GeV; we find \ensuremathσ=0.142±0.022 mb. Using the dielectron channels, the π0 and η Dalitz decay signals are reconstructed with yields fully consistent with the hadronic channels. The electron invariant masses and acceptance-corrected helicity angle distributions are found in good agreement with model predictions

Consumption of alcohol, cigarettes and illegal substances among physicians and medical students in Brandenburg and Saxony (Germany)

<p>Abstract</p> <p>Background</p> <p>Patients regard health care professionals as role models for leading a healthy lifestyle. Health care professionals' own behaviour and attitudes concerning healthy lifestyle have an influence in counselling patients. The aim of this study was to assess consumption of alcohol, cigarettes and illegal substances among physicians and medical students in two German states: Brandenburg and Saxony.</p> <p>Methods</p> <p>Socio-demographic data and individual risk behaviour was collected by an anonymous self-administered questionnaire. Physicians were approached via mail and students were recruited during tutorials or lectures.</p> <p>Results</p> <p>41.6% of physicians and 60.9% of medical students responded to the questionnaire; more than 50% of the respondents in both groups were females. The majority of respondents consumed alcohol at least once per week; median daily alcohol consumption ranged from 3.88 g/d (female medical students) to 12.6 g/d (male physicians). A significantly higher percentage of men (p < 0.05) reported hazardous or harmful drinking compared to women. A quarter of all participating physicians and one third of all students indicated unhealthy alcohol-drinking behaviour. The majority of physicians (85.7%) and medical students (78.5%) were non-smokers. Both groups contained significantly more female non-smokers (p < 0.05). Use of illegal substances was considerably lower in physicians (5.1%) than medical students (33.0%). Male students indicated a significantly (p < 0.001) higher level of illegal drug-use compared to female students.</p> <p>Conclusion</p> <p>More than one third of the medical students and health care professionals showed problematic alcohol-drinking behaviour. Although the proportion of non-smokers in the investigated sample was higher than in the general population, when compared to the general population, medical students between 18-24 reported higher consumption of illegal substances.</p> <p>These results indicate that methods for educating and promoting healthy lifestyle, particularly with respect to excessive alcohol consumption, tobacco use and abuse of illegal drugs should be considered.</p

A systematic review and meta-analysis of the effects of clinical pathways on length of stay, hospital costs and patient outcomes

Background. To perform a systematic review about the effect of using clinical pathways on length of stay (LOS), hospital costs and patient outcomes. To provide a framework for local healthcare organisations considering the effectiveness of clinical pathways as a patient management strategy. Methods. As participants, we considered hospitalized children and adults of every age and indication whose treatment involved the management strategy "clinical pathways". We include only randomised controlled trials (RCT) and controlled clinical trials (CCT), not restricted by language or country of publication. Single measures of continuous and dichotomous study outcomes were extracted from each study. Separate analyses were done in order to compare effects of clinical pathways on length of stay (LOS), hospital costs and patient outcomes. A random effects meta-analysis was performed with untransformed and log transformed outcomes. Results. In total 17 trials met inclusion criteria, representing 4,070 patients. The quality of the included studies was moderate and studies reporting economic data can be described by a very limited scope of evaluation. In general, the majority of studies reporting economic data (LOS and hospital costs) showed a positive impact. Out of 16 reporting effects on LOS, 12 found significant shortening. Furthermore, in a subgroup-analysis, clinical pathways for invasive procedures showed a stronger LOS reduction (weighted mean difference (WMD) -2.5 days versus -0.8 days)). There was no evidence of differences in readmission to hospitals or in-hospital complications. The overall Odds Ratio (OR) for re-admission was 1.1 (95% CI: 0.57 to 2.08) and for in-hospital complications, the overall OR was 0.7 (95% CI: 0.49 to 1.0). Six studies examined costs, and four showed significantly lower costs for the pathway group. However, heterogeneity between studies reporting on LOS and cost effects was substantial. Conclusion. As a result of the relatively small number of studies meeting inclusion criteria, this evidence base is not conclusive enough to provide a replicable framework for all pathway strategies. Considering the clinical areas for implementation, clinical pathways seem to be effective especially for invasive care. When implementing clinical pathways, the decision makers need to consider the benefits and costs under different circumstances (e.g. market forces)

Physical rehabilitation for critical illness myopathy and neuropathy

Background: intensive care unit (ICU) acquired or generalised weakness due to critical illness myopathy (CIM) and polyneuropathy (CIP) are major causes of chronically impaired motor function that can affect activities of daily living and quality of life. Physical rehabilitation of those affected might help to improve activities of daily living.Objectives: our primary objective was to assess the effects of physical rehabilitation therapies and interventions for people with CIP and CIM in improving activities of daily living such as walking, bathing, dressing and eating. Secondary objectives were to assess effects on muscle strength and quality of life, and to assess adverse effects of physical rehabilitation.Search methods: on 16 July 2014 we searched the Cochrane Neuromuscular Disease Group Specialized Register and on 14 July 2014 we searched CENTRAL, MEDLINE, EMBASE and CINAHL Plus. In July 2014, we searched the Physiotherapy Evidence Database (PEDro, http://www.pedro.org.au/) and three trials registries for ongoing trials and further data about included studies. There were no language restrictions. We also handsearched relevant conference proceedings and screened reference lists to identify further trials.Selection criteria: we planned to include randomised controlled trials (RCTs), quasi-RCTs and randomised controlled cross-over trials of any rehabilitation intervention in people with acquired weakness syndrome due to CIP/CIM.Data collection and analysis: we would have extracted data, assessed the risk of bias and classified the quality of evidence for outcomes in duplicate, according to the standard procedures of The Cochrane Collaboration. Outcome data collection would have been for activities of daily living (for example, mobility, walking, transfers and self care). Secondary outcomes included muscle strength, quality of life and adverse events.Main results: the search strategy retrieved 3587 references. After examination of titles and abstracts, we retrieved the full text of 24 potentially relevant studies. None of these studies met the inclusion criteria of our review. No data were suitable to be included in a meta-analysis.Authors' conclusions: there are no published RCTs or quasi-RCTs that examine whether physical rehabilitation interventions improve activities of daily living for people with CIP and CIM. Large RCTs, which are feasible, need to be conducted to explore the role of physical rehabilitation interventions for people with CIP and CIM