The importance of sedimenting organic matter, relative to oxygen and temperature, in structuring lake profundal macroinvertebrate assemblages

We quantified the role of a main food resource, sedimenting organic matter (SOM), relative to oxygen (DO) and temperature (TEMP) in structuring profundal macroinvertebrate assemblages in boreal lakes. SOM from 26 basins of 11 Finnish lakes was analysed for quantity (sedimentation rates), quality (C:N:P stoichiometry) and origin (carbon stable isotopes, d13C). Hypolimnetic oxygen and temperature were measured from each site during summer stratification. Partial canonical correspondence analysis (CCA) and partial regression analyses were used to quantify contributions of SOM, DO and TEMP to community composition and three macroinvertebrate metrics. The results suggested a major contribution of SOM in regulating the community composition and total biomass. Oxygen best explained the Shannon diversity, whereas TEMP had largest contribution to the variation of Benthic Quality Index. Community composition was most strongly related to d13C of SOM. Based on additional d13C and stoichiometric analyses of chironomid taxa, marked differences were apparent in their utilization of SOM and body stoichiometry; taxa characteristic of oligotrophic conditions exhibited higher C:N ratios and lower C:P and N:P ratios compared to the species typical of eutrophic lakes. The results highlight the role of SOM in regulating benthic communities and the distributions of individual species, particularly in oligotrophic systems

Clinical, physiologic, and radiographic factors contributing to development of hypoxemia in moderate to severe COPD:a cohort study

Background: Hypoxemia is a major complication of COPD and is a strong predictor of mortality. We previously identified independent risk factors for the presence of resting hypoxemia in the COPDGene cohort. However, little is known about characteristics that predict onset of resting hypoxemia in patients who are normoxic at baseline. We hypothesized that a combination of clinical, physiologic, and radiographic characteristics would predict development of resting hypoxemia after 5-years of follow-up in participants with moderate to severe COPD Methods: We analyzed 678 participants with moderate-to-severe COPD recruited into the COPDGene cohort who completed baseline and 5-year follow-up visits and who were normoxic by pulse oximetry at baseline. Development of resting hypoxemia was defined as an oxygen saturation ≤88% on ambient air at rest during follow-up. Demographic and clinical characteristics, lung function, and radiographic indices were analyzed with logistic regression models to identify predictors of the development of hypoxemia. Results: Forty-six participants (7%) developed resting hypoxemia at follow-up. Enrollment at Denver (OR 8.30, 95%CI 3.05–22.6), lower baseline oxygen saturation (OR 0.70, 95%CI 0.58–0.85), self-reported heart failure (OR 6.92, 95%CI 1.56–30.6), pulmonary artery (PA) enlargement on computed tomography (OR 2.81, 95%CI 1.17–6.74), and prior severe COPD exacerbation (OR 3.31, 95%CI 1.38–7.90) were independently associated with development of resting hypoxemia. Participants who developed hypoxemia had greater decline in 6-min walk distance and greater 5-year decline in quality of life compared to those who remained normoxic at follow-up. Conclusions: Development of clinically significant hypoxemia over a 5-year span is associated with comorbid heart failure, PA enlargement and severe COPD exacerbation. Further studies are needed to determine if treatments targeting these factors can prevent new onset hypoxemia. Trial registration COPDGene is registered at ClinicalTrials.gov: NCT00608764 (Registration Date: January 28, 2008) Electronic supplementary material The online version of this article (doi:10.1186/s12890-016-0331-0) contains supplementary material, which is available to authorized users

Extracorporeal high intensity focused ultrasound for renal tumours: a 3-year follow-up.

OBJECTIVE: To determine whether primary extracorporeal high-intensity focused ultrasound (HIFU) is safe, feasible and effective for managing small renal tumours. PATIENTS AND METHODS: Although surgery currently remains the standard treatment for localized renal cell carcinoma (RCC), the increasing incidence of small renal cancers has led to a shift towards nephron-sparing surgery, with associated morbidity in 20-25% of cases, and minimally invasive ablative therapies present an alternative management. HIFU results in 'trackless' homogenous tissue ablation and when administered via an extracorporeal device, is entirely noninvasive. The study comprised 17 patients (mean tumour size 2.5 cm) with radiologically suspicious renal tumours who underwent extracorporeal HIFU using the Model-JC System (Chongqing HAIFU™, China), under general anaesthesia with one overnight hospital stay. Real-time diagnostic ultrasonography was used for targeting and monitoring. Patients were followed with a clinical review and gadolinium-enhanced magnetic resonance imaging at 12 days and every 6 months for a mean of 36 months. The outcomes measures were patient morbidity and oncological efficacy of HIFU treatment. RESULTS: Of the 17 patients, 15 were treated according to protocol; two procedures were abandoned due to intervening bowel. There were no major complications related to HIFU. Radiological evidence of ablation was apparent at 12 days in seven of the 15 patients. Before the 6-month follow-up one patient had surgery due to persisting central enhancement. Fourteen patients were evaluated at the 6-month follow-up; eight tumours had involuted (mean 12% decrease in tumour area). Four patients had irregular enhancement on imaging and had alternative therapies. Ten patients remain on follow-up at a mean (range) of 36 (14-55) months after HIFU (mean 30% decrease in tumour area). There was central loss of enhancement in all. CONCLUSIONS: Renal HIFU achieves stable lesions in two-thirds of patients, with minimal morbidity, and might be appropriate in selected cases. Further trials with accurate histological follow-up are essential to fully evaluate this novel technique

An integrative review of systematic reviews related to the management of breathlessness in respiratory illnesses

Background: breathlessness is a debilitating and distressing symptom in a wide variety of diseases and still a difficult symptom to manage. An integrative review of systematic reviews of non-pharmacological and pharmacological interventions for breathlessness in non-malignant disease was undertaken to identify the current state of clinical understanding of the management of breathlessness and highlight promising interventions that merit further investigation.Methods: systematic reviews were identified via electronic databases between July 2007 and September 2009. Reviews were included within the study if they reported research on adult participants using either a measure of breathlessness or some other measure of respiratory symptoms.Results: in total 219 systematic reviews were identified and 153 included within the final review, of these 59 addressed non-pharmacological interventions and 94 addressed pharmacological interventions. The reviews covered in excess of 2000 trials. The majority of systematic reviews were conducted on interventions for asthma and COPD, and mainly focussed upon a small number of pharmacological interventions such as corticosteroids and bronchodilators, including beta-agonists. In contrast, other conditions involving breathlessness have received little or no attention and studies continue to focus upon pharmacological approaches. Moreover, although there are a number of non-pharmacological studies that have shown some promise, particularly for COPD, their conclusions are limited by a lack of good quality evidence from RCTs, small sample sizes and limited replication.Conclusions: more research should focus in the future on the management of breathlessness in respiratory diseases other than asthma and COPD. In addition, pharmacological treatments do not completely manage breathlessness and have an added burden of side effects. It is therefore important to focus more research on promising non-pharmacological intervention

Childhood Studies: A sustainable paradigm?

This article interrogates what are frequently taken to be central commitments of Childhood Studies: the idea that children are worthy of study ‘in their own right’, that childhood is a ‘social construction’, that children are and must be treated as active agents, and that participatory methods are the gold standard. It is argued that while these ideas have been fruitful in some respects, they involve fundamental problems