47 research outputs found
Essays on Banking for Micro and Small Enterprises
This thesis provides new evidence concerning the way financial intermediaries fulfill the role of distributing capital efficiently to micro and small enterprise and diversify intertemporal risk at different stages of development. Chapter 2 and 3 present results about intertemporal risk sharing services provided by relationship banks to microentrepreneurs in developing countries after an aggregate income shock. The analysis is based on a data set in which the customer data of the microfinance institution ProCredit Ecuador is merged with the monthly data of seismic activity and explosions of the volcano Tungurahua in Ecuador from 2001 to 2006. Results indicate that new clients are less likely to receive a loan after the shock, but old clients face no lending restrictions. Additionally, old clients also pay lower interest rates after the shock and have lower default rates. The conclusion is that relationship banking facilitates intertemporal risk sharing for individuals that have a long term relationship with a bank. Chapter 4 empirically analyzes the competition between banks with different lending technologies, relationship lending and transaction lending, in the credit business with micro and small entrepreneurs in developing countries. I analyze a unique dataset consisting of a combination of credit bureau data with customer data of an Ecuadorian microfinance institution. The results support the hypothesis that especially transaction lending contributes to the problem of overindebtedness in developing countries. However, clients prefer to pay their installments to relationship banks, because they offer additional services. Chapter 5 analyzes management behavior in German credit cooperatives. One key feature of their institutional structure in the past was the fact that members have no ownership rights on the retained profits in order to assure the sustainability of the institution. Nowadays when members are mainly financially motivated and their incentives to monitor the management are weak, this institutional feature has the potential to generate negative incentives for the cooperatives management. I present a model on the incentive effects of this institutional feature and test the implications on a dataset of German credit cooperatives
The FLUXNET2015 dataset and the ONEFlux processing pipeline for eddy covariance data
The FLUXNET2015 dataset provides ecosystem-scale data on CO2, water, and energy exchange between the biosphere and the atmosphere, and other meteorological and biological measurements, from 212 sites around the globe (over 1500 site-years, up to and including year 2014). These sites, independently managed and operated, voluntarily contributed their data to create global datasets. Data were quality controlled and processed using uniform methods, to improve consistency and intercomparability across sites. The dataset is already being used in a number of applications, including ecophysiology studies, remote sensing studies, and development of ecosystem and Earth system models. FLUXNET2015 includes derived-data products, such as gap-filled time series, ecosystem respiration and photosynthetic uptake estimates, estimation of uncertainties, and metadata about the measurements, presented for the first time in this paper. In addition, 206 of these sites are for the first time distributed under a Creative Commons (CC-BY 4.0) license. This paper details this enhanced dataset and the processing methods, now made available as open-source codes, making the dataset more accessible, transparent, and reproducible.Peer reviewe
Author Correction: The FLUXNET2015 dataset and the ONEFlux processing pipeline for eddy covariance data
TRY plant trait database – enhanced coverage and open access
Plant traits - the morphological, anatomical, physiological, biochemical and phenological characteristics of plants - determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits - almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives
Identification of genetic variants associated with Huntington's disease progression: a genome-wide association study
Background Huntington's disease is caused by a CAG repeat expansion in the huntingtin gene, HTT. Age at onset has been used as a quantitative phenotype in genetic analysis looking for Huntington's disease modifiers, but is hard to define and not always available. Therefore, we aimed to generate a novel measure of disease progression and to identify genetic markers associated with this progression measure. Methods We generated a progression score on the basis of principal component analysis of prospectively acquired longitudinal changes in motor, cognitive, and imaging measures in the 218 indivduals in the TRACK-HD cohort of Huntington's disease gene mutation carriers (data collected 2008–11). We generated a parallel progression score using data from 1773 previously genotyped participants from the European Huntington's Disease Network REGISTRY study of Huntington's disease mutation carriers (data collected 2003–13). We did a genome-wide association analyses in terms of progression for 216 TRACK-HD participants and 1773 REGISTRY participants, then a meta-analysis of these results was undertaken. Findings Longitudinal motor, cognitive, and imaging scores were correlated with each other in TRACK-HD participants, justifying use of a single, cross-domain measure of disease progression in both studies. The TRACK-HD and REGISTRY progression measures were correlated with each other (r=0·674), and with age at onset (TRACK-HD, r=0·315; REGISTRY, r=0·234). The meta-analysis of progression in TRACK-HD and REGISTRY gave a genome-wide significant signal (p=1·12 × 10−10) on chromosome 5 spanning three genes: MSH3, DHFR, and MTRNR2L2. The genes in this locus were associated with progression in TRACK-HD (MSH3 p=2·94 × 10−8 DHFR p=8·37 × 10−7 MTRNR2L2 p=2·15 × 10−9) and to a lesser extent in REGISTRY (MSH3 p=9·36 × 10−4 DHFR p=8·45 × 10−4 MTRNR2L2 p=1·20 × 10−3). The lead single nucleotide polymorphism (SNP) in TRACK-HD (rs557874766) was genome-wide significant in the meta-analysis (p=1·58 × 10−8), and encodes an aminoacid change (Pro67Ala) in MSH3. In TRACK-HD, each copy of the minor allele at this SNP was associated with a 0·4 units per year (95% CI 0·16–0·66) reduction in the rate of change of the Unified Huntington's Disease Rating Scale (UHDRS) Total Motor Score, and a reduction of 0·12 units per year (95% CI 0·06–0·18) in the rate of change of UHDRS Total Functional Capacity score. These associations remained significant after adjusting for age of onset. Interpretation The multidomain progression measure in TRACK-HD was associated with a functional variant that was genome-wide significant in our meta-analysis. The association in only 216 participants implies that the progression measure is a sensitive reflection of disease burden, that the effect size at this locus is large, or both. Knockout of Msh3 reduces somatic expansion in Huntington's disease mouse models, suggesting this mechanism as an area for future therapeutic investigation
German second-opinion network for testicular cancer: Sealing the leaky pipe between evidence and clinical practice
Prävalenz der high-risk HP-Viren 16 und 18 in Plattenepithelkarzinomen des Larynx und deren Bedeutung als prognostischer Marker des Gesamtüberlebens: eine retrospektive Analyse
Einleitung: In den vergangenen Jahren konnte gezeigt werden, dass die Infektion mit dem humanen Papillomavirus einen unabhängigen Risikofaktor für die Entwicklung eines Oropharynx-Karzinoms darstellt. Für den Larynx ist die HPV-Prävalenz weit weniger gut untersucht. Wir untersuchten die Prävalenz der High risk-Typen HPV-16 und -18 in 118 Tumorgewebeproben des Larynx unserer klinikeigenen Gewebebank.Methoden: Insgesamt wurden 118 Gewebeproben mit gesichertem Plattenepithelkarzinom des Larynx untersucht. Der HPV-Nachweis erfolgte zunächst mittels einer Screening PCR. Die hier positiven Proben wurden in einer nachfolgenden zweiten PCR auf die high risk-Typen HPV 16 und HPV 18 untersucht. Desweiteren wurde immunhistochemisch die Expression von p16 untersucht. Das Gesamtüberleben wurde mittels unserer Tumordatenbank "AdOnco" und Abfragen bei den Standesämtern ermittelt.Ergebnisse: In den Gewebeproben des Larynx konnte in 20 Proben (17,0%) HPV-16 mittels PCR nachgewiesen werden. In der p16-Färbung erhielten wir 30 positive Ergebnisse (26,1%). Der Nachweis von HPV-18 konnte in keiner der untersuchten Gewebeproben erbracht werden. HPV positive Patienten wiesen ein im Schnitt ein um 30,1 Monate verlängertes Gesamtüberleben auf.Schlussfolgerungen: Unsere Untersuchungen weisen darauf hin, dass der high-risk Typ HPV-16 auch in der Carcinogenese von Larynxkarzinomen eine Rolle spielen könnte. Weiterhin sollte an größeren Kollektiven überprüft werden, ob sich das gezeigte verbesserte Gesamtüberleben reproduzieren lässt.Der Erstautor gibt keinen Interessenkonflikt an
The prognostic impact of Claudin 6 in papillary renal cell carcinoma
Background: Claudins are promising biomarkers for diagnosis and prognosis or targets for treatment. They play a major role in signal transduction and are important in nearly all aspects of tumorigenesis. Claudin 6 is a member of the claudin family and is part of the tight junction molecule. It is reactivated in several cancer types and serves as prognostic marker in, for example, gastric, breast or non small cell lung cancer. The prognostic role of Claudin 6 in renal cell carcinoma (RCC), especially in papillary RCC (pRCC), is still unclear. Patients and Methods: The patients' sample collection was a joint collaboration of the PANZAR consortium. Patients' medical history and tumor specimens were collected from n = 240 and n = 128 patients with type 1 and 2 pRCC, respectively. Expression of Claudin 6 was determined by immunohistochemistry. Results: In total, Claudin 6 staining was positive in 55 of 240 type 1 and 30 of 128 type 2 pRCC cases. Kaplan-Meier analysis disclosed an overall survival of 84% for Claudin 6-compared to 78% for Claudin 6 + in pRCC type 1 tumors (p = 0.449, log-rank) and 68% for Claudin 6-compared to 65.4% for Claudin 6 + in pRCC type 2 tumors (p = 0.364, log-rank). Conclusion: In this study, claudin 6 expression showed no significant association regarding overall survival (OS) and therefore did not qualify as a prognostic marker in pRCC. Future studies will have to determine, whether Claudin 6 plays a prognostic role in other RCC entities. In addition, the function of Claudin 6 as a predictive marker for therapeutic approaches has to be evaluated in future studies