Functional measures and food webs of high elevation springs in the Swiss alps

Abstract.: We examined the ecosystem functioning and food webs of high elevation springs in or near the Swiss National Park. Springs originated from silicate or carbonate geologies and were near or above treeline. One iron-sulphur and three temporary springs were also included in the study. Ecosystem function was assessed in four springs via measures of bacterial abundance, sediment respiration, nutrient uptake, and ecosystem metabolism. Food webs were assessed in all 20 springs using nutrient content (C, N, P) and stable isotopes of carbon and nitrogen. Bacteria counts ranged from 1.8 to 3.4×108 cells mL−1 sediment with no significant differences between sites. Sediment respiration rates ranged from 0.13 to 0.46mg O2 h−1 and did not differ between springs. Uptake lengths for N ranged from 11 to 63 m, and for phosphorus from 4 to 60 m. Nitrogen uptake rates (U) ranged from 57 to 266μg m−2 h−1 and those for P from 0.11 to 4.2μg m−2 h−1. Gross primary production (GPP) ranged from 0.7 to 7.1 g O2 m−2 d−1, but reached values of 59.1-70.9 g O2m−2 d−1 in the iron-sulphur spring. Ecosystem respiration (ER) ranged from 1.3 to 10.3 g O2m−2 d−1, but was 91.1-101.8 g O2m−2 d−1 in the ironsulphur spring. All four springs were net-heterotrophic with production to respiration ratios (P/R) ranging from 0.48 to 0.72. The percentage C, N, and P varied significantly among the different food web compartments. The molar ratios (C:P,C:N,N:P) of the different nutrients were consistent within compartments, although varying among the different compartments. Stable isotope signatures (δ13C, d15N) were related to the specific spring types, although food webs were relatively simple with most benthic invertebrates showing omnivory. Riparian spiders partially used aquatic insects in the diet. The results suggest that these alpine springs are complex but functionally similar to forested headwater streams with simple food web

Single-patient (n-of-1) trials: a pragmatic clinical decision methodology for patient-centered comparative effectiveness research

AbstractObjectiveTo raise awareness among clinicians and epidemiologists that single-patient (n-of-1) trials are potentially useful for informing personalized treatment decisions for patients with chronic conditions.Study Design and SettingWe reviewed the clinical and statistical literature on methods and applications of single-patient trials and then critically evaluated the needs for further methodological developments.ResultsExisting literature reports application of 2,154 single-patient trials in 108 studies for diverse clinical conditions; various recent commentaries advocate for wider application of such trials in clinical decision making. Preliminary evidence from several recent pilot acceptability studies suggests that single-patient trials have the potential for widespread acceptance by patients and clinicians as an effective modality for increasing the therapeutic precision. Bayesian and adaptive statistical methods hold promise for increasing the informational yield of single-patient trials while reducing participant burden, but are not widely used. Personalized applications of single-patient trials can be enhanced through further development and application of methodologies on adaptive trial design, stopping rules, network meta-analysis, washout methods, and methods for communicating trial findings to patients and clinicians.ConclusionsSingle-patient trials may be poised to emerge as an important part of the methodological armamentarium for comparative effectiveness research and patient-centered outcomes research. By permitting direct estimation of individual treatment effects, they can facilitate finely graded individualized care, enhance therapeutic precision, improve patient outcomes, and reduce costs

L2 immersion causes non-native-like L1 pronunciation in German attriters

According to Flege׳s Speech Learning Model, the speech sounds of a bilingual׳s languages are contained in one common phonological space. This predicts bidirectional influence on the articulation of these speech sounds. We investigated the influence of a late-learned second language (L2) on the first language (L1) in a group of German L1 attriters in Anglophone North America (i.e., long-term emigrants in L2 immersion). These speakers were compared to a control group of monolingual German L1 speakers in two analyses: First, L1 speech samples of both groups were rated for native-likeness. Attriters sounded less native-like to raters, with 40% of the attriters rated below the monolingual range. Native-likeness was negatively associated with length of residence abroad and positively associated with L1 use. Second, formant analyses on four speech sounds of German—/aː/, /ɛ/, /ɔ/ and /l/—were conducted for attriters and controls. For these analyses, two attriter subgroups were formed: one with speakers who sounded native-like to raters and one with speakers who did not. It was hypothesised that the formants in both groups would shift in the direction of similar L2 speech sounds and that the shift would be stronger in non-native-like attriters. The first hypothesis was partly confirmed: At least one attriter group differed from the control group on one formant of /aː/ and /l/. These differences were consistent with predictions based on the L2. The second hypothesis was not confirmed: There was no evidence that the formants of the non-native-like attriters deviated more strongly from the monolingual baseline than those of the native-like attriters. Additionally, the formant values and the ratings were found to be only weakly associated, suggesting a different source of the perceptibly non-native-like pronunciation in some attriters

Serum creatinine as marker of kidney function in South Asians: a study of reduced GFR in adults in Pakistan

Migrant populations of South Asian origin have a higher risk for chronic kidney disease than the native whites. Several formulas have been developed to estimate kidney function from serum creatinine concentration. However, none of these has been validated in the South Asian population, which generally has different muscle mass composition than whites. A population-based cross-sectional study was performed on 262 individuals who were aged \u3e or = 40 yr in Karachi, Pakistan. Reduced GFR was defined as creatinine clearance (Ccr) measured in 24-h urine collection of /min per 1.73 m2. Creatinine excretion was compared with age- and gender-matched white individuals by comparison of observed versus expected results on the basis of a formula using t test. The agreement among Cockcroft Gault (CG) Ccr and Modification of Diet in Renal Disease (MDRD) Study GFR equations was assessed by regression analyses, and the degree of accuracy of estimated versus measured GFR was determined. Mean (95% confidence interval) creatinine excretion was 1.7 (1.0 to 2.4) mg/kg per d lower than expected for age- and gender-matched white individuals (P \u3c 0.001). The coefficient of determination for measured Ccr on the logarithmic scale was 66.7 and 55.6% for the CG and MDRD Study equations, respectively. The proportion of estimates within 20, 30, and 50% of measured Ccr values was 47.7 versus 32.8% (P \u3c 0.001), 64.9 versus 49.6% (P \u3c 0.001), and 79.4 versus 72.9 (P = 0.07) for CG versus MDRD Study equations, respectively. Lower mean creatinine excretion in these individuals may explain, in part, suboptimal agreement between estimated versus measured GFR. Inclusion of terms for ethnic and racial groups other than white and black might improve the performance of GFR estimating equations

Biosynthesis and Biological Profiling of Collinolactone and Semisynthetic Derivatives and MetaboIDent, a Novel Tool for Automated Dereplication

The rising incidences of age-related diseases such as Alzheimer and some types of cancer demand novel drugs and therapeutic concepts. Nature has already proven to be an extraordinary rich source of novel structural motifs. They can serve as lead structures for drug development like the prominent antibiotic vancomycin or the anti-cancer drug taxol. In this thesis, a novel natural product named collinolactone was isolated from Streptomyces sp. Gö 40/10. The compound possesses an unprecedented and unique 6-10-7-membered tricyclic system with a cyclodecatriene ring flanked by two lactone rings. Based on stable precursor feeding, a biosynthetic pathway via a type I polyketide synthase was postulated, which was then used for the identification of the encoding gene cluster. Follow-up CRISPR-based genetical engineering, optimization of fermentation parameters and the isolation procedure led to a high-production strain with yields of up to 100 mg/L. A representative and divers set of derivatives of collinolactone was synthesized including the use of Burgess reagent, Strykers reagent and Gilman cuprates. All compounds were profiled in a cell-viability assay on L929 cell line, where some compounds showed cytotoxicity in the micromolar range. The mode of action was studied with fluorescence microscopy on the cell cycle of PtK2 cells and an increased formation of monopolar spindles was observed. The inhibition of putative molecular targets was investigated in a malachite green ATP-based assay. Furthermore, collinolactone was found to exhibit neuroprotective properties in a glutamate induced intramolecular oxidative stress assay on HT22 cells. Only collinolactone showed an effect indicating that the binding is highly specific and even the smallest structural changes will lead to a loss of activity. In addition, the reduction of amyloid beta protein aggregates, one of the hallmarks for the development of Alzheimer disease, was studied. Again, collinolactone showed a reduction of aggregation, making it a very promising lead structure for further development towards a drug for Alzheimer therapy

Hospital ownership and quality of care: what explains the different results?

Does quality of care systematically differ among government-owned, private not-for-profit, and for-profit hospitals? A large empirical literature provides conflicting evidance. Through quantitative review of 46 studies since 1990, we find that several study features that can explain divergent results: analytic methods, disease studied, and data sources. For unprofitable care, how studies handle market competition and regional differences account for substantial variation. Policymakers should be aware that differences in results appear to arise predominately from differences between studies' analytic methods. Moreover, conventional methods of meta-analysis synthesis should be applied with great caution given the considerable overlap among studied hospitals

Biogas Upgrading: A Review of National Biomethane Strategies and Support Policies in Selected Countries

Bioenergy contributes significantly towards the share of renewable energies, in Europe and worldwide. Besides solid and liquid biofuels, gaseous biofuels, such as biogas or upgraded biogas (biomethane), are an established renewable fuel in Europe. Although many studies consider biomethane technologies, feedstock potentials, or sustainability issues, the literature on the required legislative framework for market introduction is limited. Therefore, this research aims at identifying the market and legislative framework conditions in the three leading biomethane markets in Europe and compare them to the framework conditions of the top six non-European biomethane markets. This study shows the global status and national differences in promoting this renewable energy carrier. For the cross-country comparison, a systematic and iterative literature review is conducted. The results show the top three European biomethane markets (Germany, United Kingdom, Sweden) and the six non-European biomethane markets (Brazil, Canada, China, Japan, South Korea, and the United States of America), pursuing different promotion approaches and framework conditions. Noteworthy cross-national findings are the role of state-level incentives, the tendency to utilise biomethane as vehicular fuel and the focus on residues and waste as feedstock for biomethane production. Presenting a cross-country comparison, this study supports cross-country learning for the promotion of renewable energies like biomethane and gives a pertinent overview of the work