1,060 research outputs found
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Enhancing microRNA167A expression in seed decreases the α-linolenic acid content and increases seed size in Camelina sativa.
Despite well established roles of microRNAs in plant development, few aspects have been addressed to understand their effects in seeds especially on lipid metabolism. In this study, we showed that overexpressing microRNA167A (miR167OE) in camelina (Camelina sativa) under a seed-specific promoter changed fatty acid composition and increased seed size. Specifically, the miR167OE seeds had a lower α-linolenic acid with a concomitantly higher linoleic acid content than the wild-type. This decreased level of fatty acid desaturation corresponded to a decreased transcriptional expression of the camelina fatty acid desaturase3 (CsFAD3) in developing seeds. MiR167 targeted the transcription factor auxin response factor (CsARF8) in camelina, as had been reported previously in Arabidopsis. Chromatin immunoprecipitation experiments combined with transcriptome analysis indicated that CsARF8 bound to promoters of camelina bZIP67 and ABI3 genes. These transcription factors directly or through the ABI3-bZIP12 pathway regulate CsFAD3 expression and affect α-linolenic acid accumulation. In addition, to decipher the miR167A-CsARF8 mediated transcriptional cascade for CsFAD3 suppression, transcriptome analysis was conducted to implicate mechanisms that regulate seed size in camelina. Expression levels of many genes were altered in miR167OE, including orthologs that have previously been identified to affect seed size in other plants. Most notably, genes for seed coat development such as suberin and lignin biosynthesis were down-regulated. This study provides valuable insights into the regulatory mechanism of fatty acid metabolism and seed size determination, and suggests possible approaches to improve these important traits in camelina
Morbus Dupuytren:eine retrospektive Analyse des Krankenguts der Klinik und Poliklinik für Unfall-, Hand-, und Wiederherstellungschirurgie des Universitätsklinikums Münster im Zeitraum vom 01.01.1987 - 31.12.1989
Diese Dissertation analysiert die Daten von 321 am M. Dupuytren erkrankten Patienten, die in 353 Operationen an 608 Fingerstrahlen in unserer Klinik behandelt wurden. Übereinstimmend mit der Literatur waren Männer im Verhältnis von 6,5:1 häufiger betroffen als Frauen. Die Altersverteilung zeigte ein Überwiegen der Erkrankung bei Personen, die sich in der 2. Lebenshälfte befanden. Der einseitige Händebefall überwog dem beidseitigen. Beim Fingerbefall dominierte die ulnare Seite der Hand. Die Zahl der familiär vorbelasteten Patienten (5%), sowie die Zahl der Patienten mit weiteren fibroplastischen Erkrankungen (5,6%) war geringer als bei anderen Autoren. Es konnte in 68% der Fälle eine volle Streckfähigkeit der Finger erzielt werden, wobei die besten Ergebnisse erreicht wurden, wenn nicht später als zum Zeitpunkt des ISELIN-Stadiums 3 operiert wurde. Die Rezidiv- und Progressionsquote lag bei erstoperierten Patienten bei 5,5%. Voroperierte Patienten zeigten eine Quote von 13,8%
Population genomic variation reveals roles of history, adaptation and ploidy in switchgrass
Citation: Grabowski, Paul P., Geoffrey P. Morris, Michael D. Casler, and Justin O. Borevitz. “Population Genomic Variation Reveals Roles of History, Adaptation and Ploidy in Switchgrass.” Molecular Ecology 23, no. 16 (2014): 4059–73. https://doi.org/10.1111/mec.12845.Geographic patterns of genetic variation are shaped by multiple evolutionary processes, including genetic drift, migration and natural selection. Switchgrass (Panicum virgatum L.) has strong genetic and adaptive differentiation despite life history characteristics that promote high levels of gene flow and can homogenize intraspecific differences, such as wind-pollination and self-incompatibility. To better understand how historical and contemporary factors shape variation in switchgrass, we use genotyping-by-sequencing to characterize switchgrass from across its range at 98 042 SNPs. Population structuring reflects biogeographic and ploidy differences within and between switchgrass ecotypes and indicates that biogeographic history, ploidy incompatibilities and differential adaptation each have important roles in shaping ecotypic differentiation in switchgrass. At one extreme, we determine that two Panicum taxa are not separate species but are actually conspecific, ecologically divergent types of switchgrass adapted to the extreme conditions of coastal sand dune habitats. Conversely, we identify natural hybrids among lowland and upland ecotypes and visualize their genome-wide patterns of admixture. Furthermore, we determine that genetic differentiation between primarily tetraploid and octoploid lineages is not caused solely by ploidy differences. Rather, genetic diversity in primarily octoploid lineages is consistent with a history of admixture. This suggests that polyploidy in switchgrass is promoted by admixture of diverged lineages, which may be important for maintaining genetic differentiation between switchgrass ecotypes where they are sympatric. These results provide new insights into the mechanisms shaping variation in widespread species and provide a foundation for dissecting the genetic basis of adaptation in switchgrass
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Effects of Medicare Payment Reform: Evidence from the Home Health Interim and Prospective Payment Systems
Medicare continues to implement payment reforms that shift reimbursement from fee-for-service towards episode-based payment, affecting average and marginal reimbursement. We contrast the effects of two reforms for home health agencies. The Home Health Interim Payment System in 1997 lowered both types of reimbursement; our conceptual model predicts a decline in the likelihood of use and costs, both of which we find. The Home Health Prospective Payment System in 2000 raised average but lowered marginal reimbursement with theoretically ambiguous effects; we find a modest increase in use and costs. We find little substantive effect of either policy on readmissions or mortality
Structural stability and thermodynamics of CrN magnetic phases from ab initio and experiment
The dynamical and thermodynamic phase stabilities of the stoichiometric
compound CrN including different structural and magnetic configurations are
comprehensively investigated using a first-principles density-functional-theory
(DFT) plus U approach in conjunction with experimental measurements of the
thermal expansion. Comparing DFT and DFT+U results with experimental data
reveals that the treatment of electron correlations using methods beyond
standard DFT is crucial. The non-magnetic face-centered cubic B1-CrN phase is
both, elastically and dynamically unstable, even under high pressure, while CrN
phases with non-zero local magnetic moments are predicted to be dynamically
stable within the framework of the DFT+U scheme. Furthermore, the impact of
different treatments for the exchange-correlation (xc)-functional is
investigated by carrying out all computations employing the local density
approximation and generalized gradient approximation. To address
finite-temperature properties, both, magnetic and vibrational contributions to
the free energy have been computed employing our recently developed spin-space
averaging method. The calculated phase transition temperature between
low-temperature antiferromagnetic and high-temperature paramagnetic (PM) CrN
variants is in excellent agreement with experimental values and reveals the
strong impact of the choice of the xc-functional. The temperature-dependent
linear thermal expansion coefficient of CrN is experimentally determined by the
wafer curvature method from a reactive magnetron sputter deposited single-phase
B1-CrN thin film with dense film morphology. A good agreement is found between
experimental and ab initio calculated linear thermal expansion coefficients of
PM B1-CrN. Other thermodynamic properties, such as the specific heat capacity,
have been computed as well and compared to previous experimental data.Comment: 10 figure
Lesion mapping of cognitive abilities linked to intelligence
The Wechsler Adult Intelligence Scale (WAIS) assesses a wide range of cognitive abilities and impairments. Factor analyses have documented four underlying indices that jointly comprise intelligence as assessed with the WAIS: verbal comprehension (VCI), perceptual organization (POI), working memory (WMI), and processing speed (PSI). We used nonparametric voxel-based lesion-symptom mapping in 241 patients with focal brain damage to investigate their neural underpinnings. Statistically significant lesion-deficit relationships were found in left inferior frontal cortex for VCI, in left frontal and parietal cortex for WMI, and in right parietal cortex for POI. There was no reliable single localization for PSI. Statistical power maps and cross-validation analyses quantified specificity and sensitivity of the index scores in predicting lesion locations. Our findings provide comprehensive lesion maps of intelligence factors, and make specific recommendations for interpretation and application of the WAIS to the study of intelligence in health and disease
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