Distinguishing the roles of dispersal in diversity maintenance and in diversity limitation

In recent years, a considerable research effort has gone into studying how dispersal might affect the diversity of local communities. While this general topic has received attention from theoretical and empirical ecologists alike, the research focus has differed between the two groups; theoretical ecologists have explored the role of dispersal in the maintenance of diversity within local communities, whereas empirical ecologists have sought to quantify the role of dispersal in limiting local diversity. In this paper we argue that, because the underlying causal relationship between dispersal and diversity is empirically unknown (e.g., flat, linear, and humped relationships have been suggested), there is no necessary relationship between the dispersal-maintained and the dispersal-limited component of diversity. In order to test and parameterize theoretical models we therefore need to develop a empirical approaches that allow us to quantify not only the dispersal-limited but also the dispersal-maintained component of diversity

Продукты ограниченного протеолиза: подходы к обнаружению и диагностические возможности в оценке тяжести патологии при эндогенной интоксикации

ПРОДУКТЫ ОГРАНИЧЕННОГО ПРОТЕОЛИЗАПРОТЕИНАЗО-ИНГИБИТОРНАЯ СИСТЕМАОТРАВЛЕНИЕ /ДИАГН /ОСЛЭНДОГЕННАЯ ИНТОКСИКАЦИЯ /ДИАГН /ОСЛСРЕДНЕМОЛЕКУЛЯРНАЯ ПЕПТИДНАЯ ФРАКЦИЯПАТОЛОГИЧЕСКИЕ ПРОЦЕССЫЛАБОРАТОРНЫЕ МЕТОДЫ И ПРОЦЕДУРЫБЕЛКОВО-ПЕПТИДНЫЕ КОМПОНЕНТ

Diagnostic validity of somatosensory evoked potentials in subgroups of patients with sciatica

The diagnostic utility of scalp-recorded somatosensory evoked potentials (SEP) in patients with sciatica has generally been regarded as low. The purpose of the present study was to determine the validity of sensory nerve SEP in different subgroups of sciatic patients. A total of 65 consecutive patients with sciatica showing disc pathology and/or facet joint hypertrophy on lumbar computed tomography (CT) and/or myelography were studied. Symptomatic myelographically compressed nerve roots were defined as truly compromised roots. Asymptomatic myelographically normal nerve roots were defined as truly normal roots. Bilateral sensory nerve SEP representing nerve roots L4, L5, and S1 were performed in all patients. Evaluation of SEP included the use of P1 latency inter-root comparison. The false-positive rate of SEP was low. Pathological L4, L5, and S1 SEP therefore strongly indicate true compromise of the corresponding nerve roots. The true-positive rate was higher in patients with facet joint hypertrophy with or without additional disc disease than in patients with disc pathology only, and highest if the sciatic sensory symptoms were present during the SEP registration. Diagnostic validity was not influenced by previous episodes of sciatica, the duration of the present episode, or the number of spinal levels with ipsilateral myelographically compressed nerve roots. Pathological SEP strongly indicate sensory radiculopathy in patients with sciatica. Diagnostic efficacy is higher in patients with facet joint hypertrophy than in patients with disc pathology only and highest when the sciatic symptoms are present during registration.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42320/1/586-11-1-38_s005860100322.pd

Meta-analysis of antibiotics versus appendicectomy for non-perforated acute appendicitis

Background: For more than a century, appendicectomy has been the treatment of choice for appendicitis. Recent trials have challenged this view. This study assessed the benefits and harms of antibiotic therapy compared with appendicectomy in patients with non-perforated appendicitis. Methods: A comprehensive search was conducted for randomized trials comparing antibiotic therapy with appendicectomy in patients with non-perforated appendicitis. Key outcomes were analysed using random-effects meta-analysis, and the quality of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Results: Five studies including 1116 patients reported major complications in 25 (4.9 per cent) of 510 patients in the antibiotic and 41 (8.4 per cent) of 489 in the appendicectomy group: risk difference -2.6 (95 per cent c.i. -6.3 to 1.1) per cent (low-quality evidence). Minor complications occurred in 11 (2.2 per cent) of 510 and 61 (12.5 per cent) of 489 patients respectively: risk difference -7.2 (-18.1 to 3.8) per cent (very low-quality evidence). Of 550 patients in the antibiotic group, 47 underwent appendicectomy within 1 month: pooled estimate 8.2 (95 per cent c.i. 5.2 to 11.8) per cent (high-quality evidence). Within 1 year, appendicitis recurred in 114 of 510 patients in the antibiotic group: pooled estimate 22.6 (15.6 to 30.4) per cent (high-quality evidence). For every 100 patients with non-perforated appendicitis, initial antibiotic therapy compared with prompt appendicectomy may result in 92 fewer patients receiving surgery within the first month, and 23 more experiencing recurrent appendicitis within the first year. Conclusion: The choice of medical versus surgical management in patients with clearly uncomplicated appendicitis is value-and preference-dependent, suggesting a change in practice towards shared decision-making is necessary.Peer reviewe

PCSK9 inhibitors and ezetimibe with or without statin therapy for cardiovascular risk reduction: a systematic review and network meta-analysis.

OBJECTIVE To compare the impact of ezetimibe and proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors on cardiovascular outcomes in adults taking maximally tolerated statin therapy or who are statin intolerant. DESIGN Network meta-analysis. DATA SOURCES Medline, EMBASE, and Cochrane Library up to 31 December 2020. ELIGIBILITY CRITERIA FOR SELECTING STUDIES Randomised controlled trials of ezetimibe and PCSK9 inhibitors with ≥500 patients and follow-up of ≥6 months. MAIN OUTCOME MEASURES We performed frequentist fixed-effects network meta-analysis and GRADE (grading of recommendations, assessment, development, and evaluation) to assess certainty of evidence. Results included relative risks (RR) and absolute risks per 1000 patients treated for five years for non-fatal myocardial infarction (MI), non-fatal stroke, all-cause mortality, and cardiovascular mortality. We estimated absolute risk differences assuming constant RR (estimated from network meta-analysis) across different baseline therapies and cardiovascular risk thresholds; the PREDICT risk calculator estimated cardiovascular risk in primary and secondary prevention. Patients were categorised at low to very high cardiovascular risk. A guideline panel and systematic review authors established the minimal important differences (MID) of 12 per 1000 for MI and 10 per 1000 for stroke. RESULTS We identified 14 trials assessing ezetimibe and PCSK9 inhibitors among 83 660 adults using statins. Adding ezetimibe to statins reduced MI (RR 0.87 (95% confidence interval 0.80 to 0.94)) and stroke (RR 0.82 (0.71 to 0.96)) but not all-cause mortality (RR 0.99 (0.92 to 1.06)) or cardiovascular mortality (RR 0.97 (0.87 to 1.09)). Similarly, adding PCSK9 inhibitor to statins reduced MI (0.81 (0.76 to 0.87)) and stroke (0.74 (0.64 to 0.85)) but not all-cause (0.95 (0.87 to 1.03)) or cardiovascular mortality (0.95 (0.87 to 1.03)). Among adults with very high cardiovascular risk, adding PCSK9 inhibitor was likely to reduce MI (16 per 1000) and stroke (21 per 1000) (moderate to high certainty); whereas adding ezetimibe was likely to reduce stroke (14 per 1000), but the reduction of MI (11 per 1000) (moderate certainty) did not reach MID. Adding ezetimibe to PCSK9 inhibitor and statin may reduce stroke (11 per 1000), but the reduction of MI (9 per 1000) (low certainty) did not reach MID. Adding PCSK9 inhibitors to statins and ezetimibe may reduce MI (14 per 1000) and stroke (17 per 1000) (low certainty). Among adults with high cardiovascular risk, adding PCSK9 inhibitor probably reduced MI (12 per 1000) and stroke (16 per 1000) (moderate certainty); adding ezetimibe probably reduced stroke (11 per 1000), but the reduction in MI did not achieve MID (8 per 1000) (moderate certainty). Adding ezetimibe to PCSK9 inhibitor and statins did not reduce outcomes beyond MID, while adding PCSK9 inhibitor to ezetimibe and statins may reduce stroke (13 per 1000). These effects were consistent in statin-intolerant patients. Among moderate and low cardiovascular risk groups, adding PCSK9 inhibitor or ezetimibe to statins yielded little or no benefit for MI and stroke. CONCLUSIONS Ezetimibe or PCSK9 inhibitors may reduce non-fatal MI and stroke in adults at very high or high cardiovascular risk who are receiving maximally tolerated statin therapy or are statin-intolerant, but not in those with moderate and low cardiovascular risk

Multiscale mapping of plant functional groups and plant traits in the High Arctic using field spectroscopy, UAV imagery and Sentinel-2A data

The Arctic is warming twice as fast as the rest of the planet, leading to rapid changes in species composition and plant functional trait variation. Landscape-level maps of vegetation composition and trait distributions are required to expand spatially-limited plot studies, overcome sampling biases associated with the most accessible research areas, and create baselines from which to monitor environmental change. Unmanned aerial vehicles (UAVs) have emerged as a low-cost method to generate high-resolution imagery and bridge the gap between fine-scale field studies and lower resolution satellite analyses. Here we used field spectroscopy data (400-2500 nm) and UAV multispectral imagery to test spectral methods of species identification and plant water and chemistry retrieval near Longyearbyen, Svalbard. Using the field spectroscopy data and Random Forest analysis, we were able to distinguish eight common High Arctic plant tundra species with 74% accuracy. Using partial least squares regression (PLSR), we were able to predict corresponding water, nitrogen, phosphorus and C:N values (r (2) = 0.61-0.88, RMSEmean = 12%-64%). We developed analogous models using UAV imagery (five bands: Blue, Green, Red, Red Edge and Near-Infrared) and scaled up the results across a 450 m long nutrient gradient located underneath a seabird colony. At the UAV level, we were able to map three plant functional groups (mosses, graminoids and dwarf shrubs) at 72% accuracy and generate maps of plant chemistry. Our maps show a clear marine-derived fertility gradient, mediated by geomorphology. We used the UAV results to explore two methods of upscaling plant water content to the wider landscape using Sentinel-2A imagery. Our results are pertinent for high resolution, low-cost mapping of the Arctic.Peer reviewe

The impact of ADHD and conduct disorder in childhood on adult delinquency: A 30 years follow-up study using official crime records

<p>Abstract</p> <p>Background</p> <p>Few longitudinal studies have explored lifetime criminality in adults with a childhood history of severe mental disorders. In the present study, we wanted to explore the association between adult delinquency and several different childhood diagnoses in an in-patient population. Of special interest was the impact of disturbance of activity and attention (ADHD) and mixed disorder of conduct and emotions on later delinquency, as these disorders have been variously associated with delinquent development.</p> <p>Methods</p> <p>Former Norwegian child psychiatric in-patients (n = 541) were followed up 19-41 years after hospitalization by record linkage to the National Register of Criminality. On the basis of the hospital records, the patients were re-diagnosed according to ICD-10. The association between diagnoses and other baseline factors and later delinquency were investigated using univariate and multivariate Cox regression analyses.</p> <p>Results</p> <p>At follow-up, 24% of the participants had been convicted of criminal activity.</p> <p>In the multivariate Cox regression analysis, conduct disorder (RR = 2.0, 95%CI = 1.2-3.4) and hyperkinetic conduct disorder (RR = 2.7, 95% CI = 1.6-4.4) significantly increased the risk of future criminal behaviour. Pervasive developmental disorder (RR = 0.4, 95%CI = 0.2-0.9) and mental retardation (RR = 0.4, 95%CI = 0.3-0.8) reduced the risk for a criminal act. Male gender (RR = 3.6, 95%CI = 2.1-6.1) and chronic family difficulties (RR = 1.3, 95% CI = 1.1-1.5) both predicted future criminality.</p> <p>Conclusions</p> <p>Conduct disorder in childhood was highly associated with later delinquency both alone or in combination with hyperactivity, but less associated when combined with an emotional disorder. ADHD in childhood was no more associated with later delinquency than the rest of the disorders in the study population. Our finding strengthens the assumption that there is no direct association between ADHD and criminality.</p

Doubtful outcome of the validation of the Rome II questionnaire: validation of a symptom based diagnostic tool

<p>Abstract</p> <p>Background</p> <p>Questionnaires are used in research and clinical practice. For gastrointestinal complaints the Rome II questionnaire is internationally known but not validated. The aim of this study was to validate a printed and a computerized version of Rome II, translated into Swedish. Results from various analyses are reported.</p> <p>Methods</p> <p>Volunteers from a population based colonoscopy study were included (n = 1011), together with patients seeking general practice (n = 45) and patients visiting a gastrointestinal specialists' clinic (n = 67). The questionnaire consists of 38 questions concerning gastrointestinal symptoms and complaints. Diagnoses are made after a special code. Our validation included analyses of the translation, feasibility, predictability, reproducibility and reliability. Kappa values and overall agreement were measured. The factor structures were confirmed using a principal component analysis and Cronbach's alpha was used to test the internal consistency.</p> <p>Results and Discussion</p> <p>Translation and back translation showed good agreement. The questionnaire was easy to understand and use. The reproducibility test showed kappa values of 0.60 for GERS, 0.52 for FD, and 0.47 for IBS. Kappa values and overall agreement for the predictability when the diagnoses by the questionnaire were compared to the diagnoses by the clinician were 0.26 and 90% for GERS, 0.18 and 85% for FD, and 0.49 and 86% for IBS. Corresponding figures for the agreement between the printed and the digital version were 0.50 and 92% for GERS, 0.64 and 95% for FD, and 0.76 and 95% for IBS. Cronbach's alpha coefficient for GERS was 0.75 with a span per item of 0.71 to 0.76. For FD the figures were 0.68 and 0.54 to 0.70 and for IBS 0.61 and 0.56 to 0.66. The Rome II questionnaire has never been thoroughly validated before even if diagnoses made by the Rome criteria have been compared to diagnoses made in clinical practice.</p> <p>Conclusion</p> <p>The accuracy of the Swedish version of the Rome II is of doubtful value for clinical practice and research. The results for reproducibility and reliability were acceptable but the outcome of the predictability test was poor with IBS as an exception. The agreement between the digital and the paper questionnaire was good.</p

The handbook for standardized field and laboratory measurements in terrestrial climate change experiments and observational studies (ClimEx)

Climate change is a world-wide threat to biodiversity and ecosystem structure, functioning and services. To understand the underlying drivers and mechanisms, and to predict the consequences for nature and people, we urgently need better understanding of the direction and magnitude of climate change impacts across the soil-plant-atmosphere continuum. An increasing number of climate change studies are creating new opportunities for meaningful and high-quality generalizations and improved process understanding. However, significant challenges exist related to data availability and/or compatibility across studies, compromising opportunities for data re-use, synthesis and upscaling. Many of these challenges relate to a lack of an established 'best practice' for measuring key impacts and responses. This restrains our current understanding of complex processes and mechanisms in terrestrial ecosystems related to climate change. To overcome these challenges, we collected best-practice methods emerging from major ecological research networks and experiments, as synthesized by 115 experts from across a wide range of scientific disciplines. Our handbook contains guidance on the selection of response variables for different purposes, protocols for standardized measurements of 66 such response variables and advice on data management. Specifically, we recommend a minimum subset of variables that should be collected in all climate change studies to allow data re-use and synthesis, and give guidance on additional variables critical for different types of synthesis and upscaling. The goal of this community effort is to facilitate awareness of the importance and broader application of standardized methods to promote data re-use, availability, compatibility and transparency. We envision improved research practices that will increase returns on investments in individual research projects, facilitate second-order research outputs and create opportunities for collaboration across scientific communities. Ultimately, this should significantly improve the quality and impact of the science, which is required to fulfil society's needs in a changing world.Peer reviewe