96 research outputs found
Vergleich von Trockenstressperioden unter derzeitigem und zukünftigem Klima für verschiedene Baumarten
Zum Vergleich derzeitiger mit künftigen, möglichen Standortswasserhaushalte sowie von Perioden mit potentiellem Trockenstress unterschiedlicher Baumarten wurden zwei Niederschlagsrealisationen des A1B-Szenario für 2071-2100 sowie des Ist-Klimas (1961-90) mit dem physika-lisch basierten Modell LWF-BROOK90 für einen trocken-warmen (Würzburg) sowie einen mittleren Standort (Freising) berechnet. In Würzburg zeigte sich bei allen betrachteten Baumarten (Eiche, Buche, Fichte) ein Rückgang der aktuellen Verdunstung in den Szenarien, während es in Freising zu einer Zunahme kam. Da gleichzeitig die Verdunstungsdifferenz in Würzburg deutlich ansteigt, ist nicht mehr genügend Wasser vorhanden, um dort den sommerlichen Verdunstungsanspruch des wärmer werdenden Klimas zu erfüllen. Die Grundwasserneubildung nimmt in Freising im trockenen Szenario ab, während sie in Würzburg in beiden Szenarien ansteigt. Folge der dort starken Umverteilung des Niederschlags ins Winterhalbjahr. In künf-tigen Extremjahren tritt die Transpirationsdifferenz früher und länger bei vergleichbarer Höhe wie im Jahrhundertsommer 2003 auf
Quality of life and hormone use: new validation results of MRS scale
BACKGROUND: The Menopause Rating Scale is a health-related Quality of Life scale developed in the early 1990s and step-by-step validated since then. Recently the MRS scale was validated as outcomes measure for hormone therapy. The suspicion however was expressed that the data were too optimistic due to methodological problems of the study. A new study became available to check how founded this suspicion was. METHOD: An open post-marketing study of 3282 women with pre- and post- treatment data of the self-administered version of the MRS scale was analyzed to evaluate the capacity of the scale to detect hormone treatment related effects with the MRS scale. The main results were then compared with the old study where the interview-based version of the MRS scale was used. RESULTS: The hormone-therapy related improvement of complaints relative to the baseline score was about or less than 30% in total or domain scores, whereas it exceeded 30% improvement in the old study. Similarly, the relative improvement after therapy, stratified by the degree of severity at baseline, was lower in the new than in the old study, but had the same slope. Although we cannot exclude different treatment effects with the study method used, this supports our hypothesis that the individual MRS interviews performed by the physician biased the results towards over-estimation of the treatment effects. This hypothesis is underlined by the degree of concordance of physician's assessment and patient's perception of treatment success (MRS results): Sensitivity (correct prediction of the positive assessment by the treating physician) of the MRS and specificity (correct prediction of a negative assessment by the physician) were lower than the results obtained with the interview-based MRS scale in the previous publication. CONCLUSION: The study confirmed evidence for the capacity of the MRS scale to measure treatment effects on quality of life across the full range of severity of complaints before treatment. The difference of the relative improvement after therapy between the old and current study as well as the observed different sensitivity/specificity is – as a matter of probability – more likely to be caused by a bias introduced by the different application of the MRS scale than by real differences in the efficacy of the therapy. A randomized clinical trial would be needed to test the impact of the latter. The message for future studies is: The MRS scale should be only used as self-administered tool where the suggestive effect of questions raised by health professionals ("therapeutic optimism") can be largely excluded
Genetical and functional investigation of fliC genes encoding flagellar serotype H4 in wildtype strains of Escherichia coli and in a laboratory E. coli K-12 strain expressing flagellar antigen type H48
BACKGROUND: Serotyping of O-(lipopolysaccharide) and H-(flagellar) antigens is a wideley used method for identification of pathogenic strains and clones of Escherichia coli. At present, 176 O- and 53 H-antigens are described for E. coli which occur in different combinations in the strains. The flagellar antigen H4 is widely present in E. coli strains of different O-serotypes and pathotypes and we have investigated the genetic relationship between H4 encoding fliC genes by PCR, nucleotide sequencing and expression studies. RESULTS: The complete nucleotide sequence of fliC genes present in E. coli reference strains U9-41 (O2:K1:H4) and P12b (O15:H17) was determined and both were found 99.3% (1043 of 1050 nucleotides) identical in their coding sequence. A PCR/RFLP protocol was developed for typing of fliC-H4 strains and 88 E. coli strains reacting with H4 antiserum were investigated. Nucleotide sequencing of complete fliC genes of six E. coli strains which were selected based on serum agglutination titers, fliC-PCR genotyping and reference data revealed 96.6 to 100% identity on the amino acid level. The functional expression of flagellin encoded by fliC-H4 from strain U9-41 and from our strain P12b which is an H4 expressing variant type was investigated in the E. coli K-12 strain JM109 which encodes flagellar type H48. The fliC recombinant plasmid carrying JM109 strains reacted with both H4 and H48 specific antisera whereas JM109 reacted only with the H48 antiserum. By immunoelectron microscopy, we could show that the flagella made by the fliC-H4 recombinant plasmid carrying strain are constituted of H48 and H4 flagellins which are co-assembled into functional flagella. CONCLUSION: The flagellar serotype H4 is encoded by closely related fliC genes present in serologically different types of E. coli strainswhich were isolated at different time periods and geographical locations. Our expression studies show for the first time, that flagellins of different molecular weigth are functionally expressed and coassembled in the same flagellar filament in E. coli
A systematic comparison and evaluation of biclustering methods for gene expression data
Motivation: In recent years, there have been various efforts to overcome the limitations of standard clustering approaches for the analysis of gene expression data by grouping genes and samples simultaneously. The underlying concept, which is often referred to as biclustering, allows to identify sets of genes sharing compatible expression patterns across subsets of samples, and its usefulness has been demonstrated for different organisms and datasets. Several biclustering methods have been proposed in the literature; however, it is not clear how the different techniques compare with each other with respect to the biological relevance of the clusters as well as with other characteristics such as robustness and sensitivity to noise. Accordingly, no guidelines concerning the choice of the biclustering method are currently available. Results: First, this paper provides a methodology for comparing and validating biclustering methods that includes a simple binary reference model. Although this model captures the essential features of most biclustering approaches, it is still simple enough to exactly determine all optimal groupings; to this end, we propose a fast divide-and-conquer algorithm (Bimax). Second, we evaluate the performance of five salient biclustering algorithms together with the reference model and a hierarchical clustering method on various synthetic and real datasets for Saccharomyces cerevisiae and Arabidopsis thaliana. The comparison reveals that (1) biclustering in general has advantages over a conventional hierarchical clustering approach, (2) there are considerable performance differences between the tested methods and (3) already the simple reference model delivers relevant patterns within all considered settings. Availability: The datasets used, the outcomes of the biclustering algorithms and the Bimax implementation for the reference model are available at Contact: [email protected] Supplementary information: Supplementary data are available a
Einflüsse der Pedotransferfunktionen auf Ergebnisse bodenhydrologischer Modellierung an Waldstandorten
Zur numerischen Berechnung von Größen
des Bodenwasserhaushalts für die forstliche
Beratung mit dem physikalisch basierten
Modell LWF-BROOK90 werden sechs
unterschiedliche Pedotransferfunktionen
(PTF) auf ihre Güte und Vielseitigkeit hin
an 22 bayrischen Waldklimastationen getestet.
Ziel ist es dabei, diejenige zur Verwendung
in einem Standortinformationssystem
am besten geeignete PTF zu ermitteln,
welche im Rahmen umfangreicher
Modellierungen mit unterschiedlichsten
Boden- und Klimadaten für die Waldfläche
Bayerns eingesetzt werden kann. Zum einen
werden hierzu die simulierten Bodenwassergehalte
unterschiedlicher Standorte
und Tiefenstufen mit TDR-Messungen über
vier Jahre validiert. Es zeigt sich ein äußerst
heterogenes Verhalten der Simulationsgüte
je nach bodenphysikalischen Voraussetzungen.
Zum anderen werden die
PTF hinsichtlich der Streuungen abgeleiteter
Wasserhaushaltsgrößen zur Charakterisierung
der Trockenheits- und Staunässebedingungen
eines Standortes deskriptiv
verglichen. Als Parameter dienen hierbei
die Transpirationsdifferenz TDIFF und ein
Luftmangelindikator des Oberbodens, für
die die Verteilungen und Sensitivitäten der
untersuchten PTF bestimmbar sind. Die
Auswertungen ergeben, dass jede Funktion
mit Schwächen behaftet ist und dass
keine bayernweit allgemein gültige PTF
existiert, wenn eine möglichst exakte Anpassung
an reale Bodenwassergehalte
angestrebt wird. Daher müssen zur Wahl
einer Funktion auch weitere Eigenschaften
der PTF wie Flexibilität und Robustheit berücksichtigt
werden
The Aging Males' Symptoms (AMS) scale: Update and compilation of international versions
BACKGROUND: The interest of clinical research in aging males increased in recent years and thereby the interest to measure health-related quality of life (HRQoL) and symptoms of aging men. The Aging Males' Symptoms scale (AMS) became the most commonly used scale to measure HRQoL and symptoms in aging males in many countries worldwide. The aim of this paper is to review the current state of the instrument particularly concerning versions of the scale in different languages in the light of the quality of the translation process. AMS VERSIONS AVAILABLE: Most of the translations were performed following international methodological recommendations for linguistic & cultural adaptation of HRQoL instruments. Mainly the English version was used as source language for the translation into Dutch, Spanish, Portuguese, Italian, Swedish, and Japanese (attached as additional PDF-files). Preliminary versions that were derived only from forward translations are of secondary quality and available in Finnish, Flemish, and Russian. It is recommended to complete the translation process for the latter languages before using them in international studies. TRANSLATIONS IN PROCESS: The AMS scale is in the process of consensus finding of two existing French versions, and the versions in the Korean, Thai, and Indonesian languages have not yet been completed in the translation process. CONCLUSION: The AMS scale is obviously a valuable tool for assessing health related quality of life in aging men, because it is used worldwide. It is a standardized scale according to psychometric norms. Most of the currently available language versions were translated following international standards for linguistic and cultural translation of quality of life scales. Assistance is offered to help interested parties in the translation process
Sparse graphical Gaussian modeling of the isoprenoid gene network in Arabidopsis thaliana
We present a novel graphical Gaussian modeling approach for reverse engineering of genetic regulatory networks with many genes and few observations. When applying our approach to infer a gene network for isoprenoid biosynthesis in Arabidopsis thaliana, we detect modules of closely connected genes and candidate genes for possible cross-talk between the isoprenoid pathways. Genes of downstream pathways also fit well into the network. We evaluate our approach in a simulation study and using the yeast galactose network
Developing a Nationwide Infrastructure for Therapeutic Drug Monitoring of Targeted Oral Anticancer Drugs: The ON-TARGET Study Protocol
Exposure-efficacy and/or exposure-toxicity relationships have been identified for up to 80% of oral anticancer drugs (OADs). Usually, OADs are administered at fixed doses despite their high interindividual pharmacokinetic variability resulting in large differences in drug exposure. Consequently, a substantial proportion of patients receive a suboptimal dose. Therapeutic Drug Monitoring (TDM), i.e., dosing based on measured drug concentrations, may be used to improve treatment outcomes. The prospective, multicenter, non-interventional ON-TARGET study (DRKS00025325) aims to investigate the potential of routine TDM to reduce adverse drug reactions in renal cell carcinoma patients receiving axitinib or cabozantinib. Furthermore, the feasibility of using volumetric absorptive microsampling (VAMS), a minimally invasive and easy to handle blood sampling technique, for sample collection is examined. During routine visits, blood samples are collected and sent to bioanalytical laboratories. Venous and VAMS blood samples are collected in the first study phase to facilitate home-based capillary blood sampling in the second study phase. Within one week, the drug plasma concentrations are measured, interpreted, and reported back to the physician. Patients report their drug intake and toxicity using PRO-CTCAE-based questionnaires in dedicated diaries. Ultimately, the ON-TARGET study aims to develop a nationwide infrastructure for TDM for oral anticancer drugs
Persistent anthrax as a major driver of wildlife mortality in a tropical rainforest
Anthrax is a globally important animal disease and zoonosis. Despite this, our current knowledge of anthrax ecology is largely limited to arid ecosystems, where outbreaks are most commonly reported. Here we show that the dynamics of an anthrax-causing agent, Bacillus cereus biovar anthracis, in a tropical rainforest have severe consequences for local wildlife communities. Using data and samples collected over three decades, we show that rainforest anthrax is a persistent and widespread cause of death for a broad range of mammalian hosts. We predict that this pathogen will accelerate the decline and possibly result in the extirpation of local chimpanzee (Pan troglodytes verus) populations. We present the epidemiology of a cryptic pathogen and show that its presence has important implications for conservation
Persistent anthrax as a major driver of wildlife mortality in a tropical rainforest
Anthrax is a globally important animal disease and zoonosis. Despite this, our current knowledge of anthrax ecology is largely limited to arid ecosystems, where outbreaks are most commonly reported. Here we show that the dynamics of an anthrax-causing agent, Bacillus cereus biovar anthracis, in a tropical rainforest have severe consequences for local wildlife communities. Using data and samples collected over three decades, we show that rainforest anthrax is a persistent and widespread cause of death for a broad range of mammalian hosts. We predict that this pathogen will accelerate the decline and possibly result in the extirpation of local chimpanzee (Pan troglodytes verus) populations. We present the epidemiology of a cryptic pathogen and show that its presence has important implications for conservation
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