97 research outputs found
The effects of drought stress on assimilate availability and metabolism in the source and sink organs of common bean (Phaseolus vulgaris L) genotypes
Changes in carbohydrate status and metabolism in the source and sink organs determine rate of growth and yield of plants subjected to drought stress. The objective of this study was to assess the effect of lost-flowering drought stress on assimilate synthesis at source level and availability of the assimilates for metabolism in the reproductive sink organs of common bean (Phaseolus vulgaris L.) genotypes differing in degree of drought resistance. A drought-resistant inbred line (SEA 15) and a drought-susceptible cultivar (BrSp) were grown under non-stress and drought stress commenced at early pod-filling stage. Plants were raised in a vegetation hall during the summer of 2005. Drought stress reduced the seed yields of BrSp and SEA 15 by 53 and 30%, respectively. Harvest index of the susceptible genotype decreased by ca. 29%, whereas no effect of drought was found for the partitioning index in the resistant genotype implying marked differences in sink strength at whole plant level between the genotypes. Drought stress did not affect the concentration of sucrose in leaves and seeds of SEA 15 during most part of the stress period. On the contrary, the stress caused 18 to 30 and 29 to 47% reductions in leaf and seed sucrose concentrations of BrSp, respectively. Relative to control treatments, drought stress decreased seed starch ccumulation of BrSp throughout the stress period (by 16 to 18%) whereas the decrease (by 20%) was found only at 20 d stress for SEA 15. The findings revealed that the underlying differences in sink establishment and yield of the bean genotypes differing in degree of drought resistance reside primarily in the capacity of the source to supply assimilates (i.e. source-strength) under drought conditions
Effects of drought stress on seed sink strength and leaf protein patterns of common bean genotypes
Assimilate availability and the capacity to utilise them in the
reproductive structures to a large extent determine reproductive sink
establishment and yield of crops under drought stress. This study was
carried out to investigate the effect of drought stress imposed at
early pod-fill stage on seed sink strength of common bean ( Phaseolus
vulgaris L.) genotypes differing in drought resistance. Quantitative
and qualitative changes in leaf protein patterns was assessed using
2D-gel electrophoresis. A drought-resistant inbred line (SEA 15) and a
droughtsusceptible cultivar (BrSp) were grown under non-stress and
drought stress conditions in a vegetation hall during the summer of
2004. Drought stress commenced at early pod-filling stage caused 53 and
30% seed yield reductions in BrSp and SEA 15, respectively. The effect
of drought on seed yield was primarily due to the significant reduction
in number of seeds per plant (48% for BrSp vs. 35% for SEA 15). Whereas
seed sucrose concentrations of BrSp decreased by 29 to 47% under
drought conditions, the stress resulted in an increase (up to 43%) in
concentration of the carbohydrate in SEA 15 seeds. Despite the
genotypic difference found for seed sucrose import, seed starch
accumulations of the two genotypes decreased under drought stress. For
both genotypes, none of the seed sink capacity parameters (numbers and
volumes of cotyledonary cells and starch granules per seed) were
significantly affected by the stress imposed implying that the
drought-induced decrease in seed starch accumulation could be due to
limitations in assimilate availability and/or other sink activity
factors within the seed. A total of 230 leaf proteins were
differentially expressed due to drought out of which 23.5, 15.1, 4.3
and 3.5% were down-regulated, up-regulated, newly appeared and
disappeared, respectively. Identification and assigning possible
functions in the crop\u2019s response to drought of the stress-induced
proteins warrant further study.La disponibilit\ue9 des assimilats et la capacit\ue9 de les
utiliser dans des structures reproductrices, d\ue9terminent en grande
partie l\u2019\ue9tablissement du \u201csink\u201d reproducteur et
les rendements des cultures en conditions de secheresse. Cette
\ue9tude avait pour objectif l\u2019\ue9tude de l\u2019effet du
stress hydrique impos\ue9 au stade du remplissage des gousses, sur la
consistence du \u201csink\u201d de graines de g\ue9notypes du
haricot commun ( Phaseolus vulgaris L.) de diff\ue9rente
r\ue9sistance \ue0 la secheresse. Des changements quantitatfs et
qualitatifs dans les structures de prot\ue9ine des feuilles
\ue9taient \ue9valu\ue9s par l\u2019\ue9lectrophor\ue8se
2D-gel.Une souche pure r\ue9sistante \ue0 la s\ue9cheresse (MER
15) et un cultivar non r\ue9sistant \ue0 la s\ue9cheresse (BrSp)
\ue9taient cultiv\ue9s \ue0 la fois en conditions de stess et
sans stress hydrique dans un hall de vegetation au cours de
l\u2019\ue9t\ue9 2004. Le stress hydrique impos\ue9 t\uf4t au
stade de remplissage de gousses a entrain\ue9 une r\ue9duction de
rendement en grains de 53 \ue0 30% dans BrSp et SEA 15,
respectivement. L\u2019effet du stress hydrique sur le rendement en
grains \ue9tait principalement d\ufb \ue0 la r\ue9duction
significative du nombre de grains par plant (48% pour BrSp contre 35%
pour SEA 15). Alors que les concentrations en sucrose dans les grains
de BrSp avaient d\ue9cru de 29 \ue0 47% en conditions de
s\ue9cheresse, la concentration en hydrates de carbone a
augment\ue9 jusqu\u2019\ue0 43% dans les grains de SEA 15.
Malgr\ue9 la diff\ue9rence g\ue9notypique trouv\ue9e pour
l\u2019importation du sucrose dans la graine, l\u2019accumulation de
l\u2019amidon dans la graine de deux genotypes a d\ue9cru en
conditions de s\ue9cheresse. Pour les deux genotypes,aucun des
param\ue8tres de la capacit\ue9 du sink du grain (nombres et
volumes de cellules de cotyledons et granules d\u2019amidon par grain)
\ue9taient significativement affect\ue9s par le stess impos\ue9,
induisant une r\ue9duction dans l\u2019accumulation de
l\u2019amidon dans le grain qui serait due \ue0 la
disponibilit\ue9 des assimilats et/ou d\u2019autres facteurs de
l\u2019activit\ue9 du sink dans la graine. Au total 230
prot\ue9ines dans les feuilles \ue9taient exprim\ue9es de
fa\ue7on diff\ue9rentielle suite \ue0 la s\ue9cheresse en
dehors de laquelle 23.5, 15.1, 4.3 et 3.5% \ue9taient respectivement
sous r\ue9gul\ue9s, sur-r\ue9gul\ue9s, nouvellement apparus et
disparus. L\u2019identification et l\u2019attribution des fonctions
possibles des prot\ue9ines sous tress induit en r\ue9ponse de la
plante \ue0 la s\ue9cheresse n\ue9cessitent une \ue9tude
suppl\ue9mentaire
A cluster of invasive meningococcal disease in young men who have sex with men in Berlin, October 2012 to May 2013
Between October 2012 and May 2013, five cases of invasive meningococcal disease in young men who have sex with men (MSM) living in Berlin were notified to local health authorities in Germany. Three of the five cases died. All were caused by serogroup C variants with the finetype P1.5-1,10-8:F3-6. Awareness was increased through the use of community networks; an extension of the existing vaccination recommendation to all MSM is currently being considered
FrĂŒhe Bildung fĂŒr nachhaltige Entwicklung. Ziele und Gelingensbedingungen
Im Rahmen der Schriftenreihe âWissenschaftliche Untersuchungen zur Arbeit der Stiftung âHaus der kleinen Forscherâ werden regelmĂ€Ăig wissenschaftliche BeitrĂ€ge von renommierten Expertinnen und Experten aus dem Bereich der frĂŒhen Bildung veröffentlicht. Diese Schriftenreihe dient einem fachlichen Dialog zwischen Stiftung, Wissenschaft und Praxis, mit dem Ziel, allen Kitas, Horten und Grundschulen in Deutschland fundierte UnterstĂŒtzung fĂŒr ihren Bildungsauftrag zu geben. Der zwölfte Band der Schriftenreihe mit einem Geleitwort von Armin Lude fokussiert die Ziele und Gelingensbedingungen einer Bildung fĂŒr nachhaltige Entwicklung fĂŒr Kinder, pĂ€dagogische FachkrĂ€fte und LeitungskrĂ€fte. Alexander Kauertz, Heike Molitor, Andrea Saffran, Susanne Schubert, Mandy Singer-Brodowski, Daniela Ulber und Johannes Verch erörtern in ihrer Expertise zentrale Zieldimensionen einer Bildung fĂŒr nachhaltige Entwicklung auf der Ebene der Kinder sowie pĂ€dagogischer Fach- und LeitungskrĂ€fte. Neben einer theoretischen Fundierung identifizieren die Autorinnen und Autoren Gelingensbedingungen fĂŒr eine effektive und wirkungsvolle frĂŒhe Bildung fĂŒr nachhaltige Entwicklung in der Praxis. Sie geben zudem Empfehlungen fĂŒr die Entwicklung der Stiftungsangebote und die wissenschaftliche Begleitung der Stiftungsarbeit zu BNE. Zwei weitere Kapitel beschreiben die Umsetzung der fachlichen Empfehlungen in die inhaltlichen Angebote der Stiftung âHaus der kleinen Forscherâ sowie die Evaluationsergebnisse zur Wirkung des Angebotsportfolios zu BNE. Ein Ausblick auf die zukĂŒnftige (Weiter-)Entwicklung der Stiftungsangebote zur Bildung fĂŒr nachhaltige Entwicklung beschlieĂt den Band. (DIPF/Orig.
A longitudinal, Bologna-compatible model curriculum "communicationand social competencies" : results of an interdisciplinary workshop of German-speaking medical schools
Zielsetzung: Ziel des Projekts ist es, ein longitudinales Modell-Curriculum "Kommunikative und soziale Kompetenzen" fĂŒr die medizinische Ausbildung zur Diskussion zu stellen. Vorgehen und Ergebnisse: Auf einem 2-tĂ€gigen Workshop wurde interfakultĂ€r und interdisziplinĂ€r auf der Grundlage des "Basler Consensus Statements: Kommunikative und soziale Kompetenzen im Medizinstudium" ein Curriculum entwickelt, das deutschsprachigen FakultĂ€ten bei der Planung und Implementierung als Vorlage dienen kann. Das Modell lĂ€sst sich als Gesamt-Curriculum oder in Teilmodulen implementieren. Es kann auch bei der Umstellung auf Bachelor- und MasterstudiengĂ€nge genutzt werden. Das longitudinale Modell-Curriculum weist neben 131 definierten Ausbildungszielen geeignete didaktische Konzepte und PrĂŒfungsformate auf und gibt VorschlĂ€ge, zu welchem Zeitpunkt die verschiedenen FĂ€cher die entsprechenden Lernziele vermitteln können. Fazit: Mit diesem longitudinalen "Modell-Curriculum Kommunikative und Soziale Kompetenzen" liegt fĂŒr den deutschen Sprachraum erstmalig ein curriculares Instrument vor, das breite Anwendung an einer Vielzahl deutscher, österreichischer und schweizerischer FakultĂ€ten finden und eine Umsetzung des Bologna-Prozesses auch fakultĂ€tsĂŒbergreifend vereinfachen kann. SchlĂŒsselwörter: Modell-Curriculum, kommunikative/soziale Kompetenzen, Basler Consensus Statement, medizinische Ausbildung, Didaktik, PrĂŒfung, Bologna-ProzessAim: The aim of the project is to present and discuss a longitudinal model curriculum "Communication and social competencies" for undergraduate medical education. Procedure and results: In a two-day workshop, a multidisciplinary, cross-faculty group of medical educators developed a curriculum model based on the "Basel Consensus Statement". It can now be used by German-speaking medical schools as a blueprint for curriculum planning and implementation processes. The modular structure enables it to be implemented either in whole or in part. The model can also be used to facilitate the conversion of medical education into Bachelor and Master degree programmes. The longitudinal model curriculum features 131 educational objectives and makes suggestions for didactic concepts and assessment tools. For various disciplines, it also recommends at what point in time specific topics should be taught. Conclusion: The longitudinal model curriculum "Communication and social competencies", based on the educational objectives of the "Basel Consensus Statement", is a new curricular instrument that can be used by German, Austrian and Swiss medical schools. It can help to simplify the realisation of the Bologna process, also across different faculties. Keywords: model curriculum, communication/social competencies, Basel Consensus Statement, undergraduate medical education, didactic, assessment, Bologna proces
Genetic Variation of the Serotonin 2a Receptor Affects Hippocampal Novelty Processing in Humans
Serotonin (5-hydroxytryptamine, 5-HT) is an important neuromodulator in learning and memory processes. A functional genetic polymorphism of the 5-HT 2a receptor (5-HTR2a His452Tyr), which leads to blunted intracellular signaling, has previously been associated with explicit memory performance in several independent cohorts, but the underlying neural mechanisms are thus far unclear. The human hippocampus plays a critical role in memory, particularly in the detection and encoding of novel information. Here we investigated the relationship of 5-HTR2a His452Tyr and hippocampal novelty processing in 41 young, healthy subjects using functional magnetic resonance imaging (fMRI). Participants performed a novelty/familiarity task with complex scene stimuli, which was followed by a delayed recognition memory test 24 hours later. Compared to His homozygotes, Tyr carriers exhibited a diminished hippocampal response to novel stimuli and a higher tendency to judge novel stimuli as familiar during delayed recognition. Across the cohort, the false alarm rate during delayed recognition correlated negatively with the hippocampal novelty response. Our results suggest that previously reported effects of 5-HTR2a on explicit memory performance may, at least in part, be mediated by alterations of hippocampal novelty processing
Comparison of proteomic responses as global approach to antibiotic mechanism of action elucidation
This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International license. New antibiotics are urgently needed to address the mounting resistance challenge. In early drug discovery, one of the bottlenecks is the elucidation of targets and mechanisms. To accelerate antibiotic research, we provide a proteomic approach for the rapid classification of compounds into those with precedented and unprecedented modes of action. We established a proteomic response library of Bacillus subtilis covering 91 antibiotics and comparator compounds, and a mathematical approach was developed to aid data analysis. Comparison of proteomic responses (CoPR) allows the rapid identification of antibiotics with dual mechanisms of action as shown for atypical tetracyclines. It also aids in generating hypotheses on mechanisms of action as presented for salvarsan (arsphenamine) and the antirheumatic agent auranofin, which is under consideration for repurposing. Proteomic profiling also provides insights into the impact of antibiotics on bacterial physiology through analysis of marker proteins indicative of the impairment of cellular processes and structures. As demonstrated for trans-translation, a promising target not yet exploited clinically, proteomic profiling supports chemical biology approaches to investigating bacterial physiology
A Mutation in Myo15 Leads to Usher-Like Symptoms in LEW/Ztm-ci2 Rats
The LEW/Ztm-ci2 rat is an animal model for syndromal deafness that arose from a spontaneous mutation. Homozygous animals show locomotor abnormalities like lateralized circling behavior. Additionally, an impaired vision can be observed in some animals through behavioral studies. Syndromal deafness as well as retinal degeneration are features of the Usher syndrome in humans. In the present study, the mutation was identified as a base substitution (T->C) in exon 56 of Myo15, leading to an amino acid exchange from leucine (Leu) to proline (Pro) within the carboxy-terminal MyTH4 domain in the proteins' tail region. Myo15 mRNA was expressed in the retina as demonstrated for the first time with the help of in-situ hybridization and PCR. To characterize the visual phenotype, rats were examined by scotopic and photopic electroretinography and, additionally, histological analyses of the retinas were conducted. The complete loss of sight was detected along with a severe degeneration of photoreceptor cells. Interestingly, the manifestation of the disease does not solely depend on the mutation, but also on environmental factors. Since the LEW/Ztm-ci2 rat features the entire range of symptoms of the human Usher syndrome we think that this strain is an appropriate model for this disease. Our findings display that mutations in binding domains of myosin XV do not only cause non-syndromic hearing loss but can also lead to syndromic disorders including retinal dysfunction
Characterisation of age and polarity at onset in bipolar disorder
Background
Studying phenotypic and genetic characteristics of age at onset (AAO) and polarity at onset (PAO) in bipolar disorder can provide new insights into disease pathology and facilitate the development of screening tools.
Aims
To examine the genetic architecture of AAO and PAO and their association with bipolar disorder disease characteristics.
Method
Genome-wide association studies (GWASs) and polygenic score (PGS) analyses of AAO (n = 12 977) and PAO (n = 6773) were conducted in patients with bipolar disorder from 34 cohorts and a replication sample (n = 2237). The association of onset with disease characteristics was investigated in two of these cohorts.
Results
Earlier AAO was associated with a higher probability of psychotic symptoms, suicidality, lower educational attainment, not living together and fewer episodes. Depressive onset correlated with suicidality and manic onset correlated with delusions and manic episodes. Systematic differences in AAO between cohorts and continents of origin were observed. This was also reflected in single-nucleotide variant-based heritability estimates, with higher heritabilities for stricter onset definitions. Increased PGS for autism spectrum disorder (ÎČ = â0.34 years, s.e. = 0.08), major depression (ÎČ = â0.34 years, s.e. = 0.08), schizophrenia (ÎČ = â0.39 years, s.e. = 0.08), and educational attainment (ÎČ = â0.31 years, s.e. = 0.08) were associated with an earlier AAO. The AAO GWAS identified one significant locus, but this finding did not replicate. Neither GWAS nor PGS analyses yielded significant associations with PAO.
Conclusions
AAO and PAO are associated with indicators of bipolar disorder severity. Individuals with an earlier onset show an increased polygenic liability for a broad spectrum of psychiatric traits. Systematic differences in AAO across cohorts, continents and phenotype definitions introduce significant heterogeneity, affecting analyses
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