83 research outputs found
Investigation of exciton properties in organic materials via many-body perturbation theory
Modeling energy transport in an organic solar cel
Cooperation of kindergarten and primary school. Activities and attitudes of kindergarten and primary school teachers
Die mangelnde Abstimmung zwischen den ersten beiden Bildungsstufen wird als ein bedeutsamer Organisationsnachteil des deutschen Bildungswesens und als potentielle Hürde auf dem Bildungsweg der Kinder betrachtet. Einer der Wege zur besseren Anschlussfähigkeit ist die Kooperation von Kindergarten und Grundschule im Umfeld des Schuleintritts der Kinder, die u.a. in ökosystemischer Sicht den Schuleintritt erleichtern soll. Der vorliegende Beitrag stellt querschnittliche Befunde aus der „BiKS“-Studie („Bildungsprozesse, Kompetenzentwicklung und Selektionsentscheidungen im Vor- und Grundschulalter“) zu den Kooperationsaktivitäten vor und bezieht dabei Hintergrundinformationen ein. Erzieherinnen (n = 77) und Erstklasslehrkräfte (n = 68) wurden zu den an ihrer Institution verbreiteten Aktivitäten und ihren Einstellungen dazu befragt. Die von den Befragten als am wichtigsten eingeschätzten Einzelmaßnahmen finden auch am häufigsten statt, nämlich Schulbesuche von angehenden Erstklässlern und der Informationsaustausch von Erzieherinnen und Lehrkräften. Die Kooperation unter Einbezug der Eltern ist seltener. Beide Befragtengruppen schätzen mit charakteristischen Unterschieden die Kooperation sehr hoch ein. Bis auf eine Schule führen alle Institutionen Kooperationsaktivitäten durch, allerdings unterscheidet sich die Breite bzw. die Häufigkeit der Maßnahmen erheblich. (DIPF/Orig.)Inadequate coordination between the first two educational stages is regarded as a substantial disadvantage in the management of the German education system and is considered as a potential drawback on children’s educational career. One way to a better alignment is the cooperation of kindergarten and primary school prior to school entry, which could also facilitate school entry from an ecosystemic point of view. Based on the “BiKS”-Study (“Educational Processes, Competence Development and Selection Decisions in Pre and Primary School Age”) this paper presents cross-sectional results regarding cooperation activities and includes background information. Kindergarten teachers (n = 77) and primary school teachers (n = 68) were asked to answer questions about common activities run by their institutions and their attitudes towards the cooperation. The two most important activities are also the most common ones: future school beginners visiting a primary school and information exchange between kindergarten and school teachers. More seldom are activities including parents. The cooperation was highly estimated by both groups of respondents with characteristic differences. Apart from one school, all institutions are involved in cooperation activities, however, the extent and frequency of the measurements differ considerably. (DIPF/Orig.
Electronic Excitations in Complex Molecular Environments: Many-Body Green's Functions Theory in VOTCA-XTP
Many-body Green's functions theory within the GW approximation and the
Bethe-Salpeter Equation (BSE) is implemented in the open-source VOTCA-XTP
software, aiming at the calculation of electronically excited states in complex
molecular environments. Based on Gaussian-type atomic orbitals and making use
of resolution of identify techniques, the code is designed specifically for
non-periodic systems. Application to the small molecule reference set
successfully validates the methodology and its implementation for a variety of
excitation types covering an energy range from 2-8 eV in single molecules.
Further, embedding each GW-BSE calculation into an atomistically resolved
surrounding, typically obtained from Molecular Dynamics, accounts for effects
originating from local fields and polarization. Using aqueous DNA as a
prototypical system, different levels of electrostatic coupling between the
regions in this GW-BSE/MM setup are demonstrated. Particular attention is paid
to charge-transfer (CT) excitations in adenine base pairs. It is found that
their energy is extremely sensitive to the specific environment and to
polarization effects. The calculated redshift of the CT excitation energy
compared to a nucelobase dimer treated in vacuum is of the order of 1 eV, which
matches expectations from experimental data. Predicted lowest CT energies are
below that of a single nucleobase excitation, indicating the possibility of an
initial (fast) decay of such an UV excited state into a bi-nucleobase CT
exciton. The results show that VOTCA-XTP's GW-BSE/MM is a powerful tool to
study a wide range of types of electronic excitations in complex molecular
environments
Finding approximate gene clusters with GECKO 3
Winter S, Jahn K, Wehner S, et al. Finding approximate gene clusters with GECKO 3. Nucleic Acids Research. 2016;44(20):9600-9610.Gene-order-based comparison of multiple genomes provides signals for functional analysis of genes and the evolutionary process of genome organization. Gene clusters are regions of co-localized genes on genomes of different species. The rapid increase in sequenced genomes necessitates bioinformatics tools for finding gene clusters in hundreds of genomes. Existing tools are often restricted to few (in many cases, only two) genomes, and often make restrictive assumptions such as short perfect conservation, conserved gene order or monophyletic gene clusters. We present Gecko 3, an open-source software for finding gene clusters in hundreds of bacterial genomes, that comes with an easy-to-use graphical user interface. The underlying gene cluster model is intuitive, can cope with low degrees of conservation as well as misannotations and is complemented by a sound statistical evaluation. To evaluate the biological benefit of Gecko 3 and to exemplify our method, we search for gene clusters in a dataset of 678 bacterial genomes using Synechocystis sp. PCC 6803 as a reference. We confirm detected gene clusters reviewing the literature and comparing them to a database of operons; we detect two novel clusters, which were confirmed by publicly available experimental RNA-Seq data. The computational analysis is carried out on a laptop computer in <40 min
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CAMP: An instrumented platform for balloon-borne aerosol particle studies in the lower atmosphere
Airborne observations of vertical aerosol particle distributions are crucial for detailed process studies and model improvements. Tethered balloon systems represent a less expensive alternative to aircraft to probe shallow atmospheric boundary layers (ABLs). This study presents the newly developed cubic aerosol measurement platform (CAMP) for balloon-borne observations of aerosol particle microphysical properties. With an edge length of 35 cm and a weight of 9 kg, the cube is an environmentally robust instrument platform intended for measurements at low temperatures, with a particular focus on applications in cloudy Arctic ABLs. The aerosol instrumentation on board CAMP comprises two condensation particle counters with different lower detection limits, one optical particle size spectrometer, and a miniaturized absorption photometer. Comprehensive calibrations and characterizations of the instruments were performed in laboratory experiments. The first field study with a tethered balloon system took place at the Leibniz Institute for Tropospheric Research (TROPOS) station in Melpitz, Germany, in the winter of 2019. At ambient temperatures between-8 and 15 C, the platform was operated up to a 1.5 km height on 14 flights under both clear-sky and cloudy conditions. The continuous aerosol observations at the ground station served as a reference for evaluating the CAMP measurements. Exemplary profiles are discussed to elucidate the performance of the system and possible process studies. Based on the laboratory instrument characterizations and the observations during the field campaign, CAMP demonstrated the capability to provide comprehensive aerosol particle measurements in cold and cloudy ABLs
The barley HvSTP13GR mutant triggers resistance against biotrophic fungi
High-yielding and stress-resistant crops are essential to ensure future food supply. Barley is an important crop to feed livestock and to produce malt, but the annual yield is threatened by pathogen infections. Pathogens can trigger an altered sugar partitioning in the host plant, which possibly leads to an advantage for the pathogen. Hampering these processes represents a promising strategy to potentially increase resistance. We analysed the response of the barley monosaccharide transporter HvSTP13 towards biotic stress and its potential use for plant protection. The expression of HvSTP13 increased on bacterial and fungal pathogen-associated molecular pattern (PAMP) application, suggesting a PAMP-triggered signalling that converged on the transcriptional induction of the gene. Promoter studies indicate a region that is probably targeted by transcription factors downstream of PAMP-triggered immunity pathways. We confirmed that the nonfunctional HvSTP13GR variant confers resistance against an economically relevant biotrophic rust fungus in barley. Our experimental setup provides basal prerequisites to further decode the role of HvSTP13 in response to biological stress. Moreover, in line with other studies, our experiments indicate that the alteration of sugar partitioning pathways, in a host–pathogen interaction, is a promising approach to achieve broad and durable resistance in plants
Hyperlipidemia is a risk factor for osteonecrosis in children and young adults with acute lymphoblastic leukemia
TesisLa intoxicación con plomo es un problema de trascendental importancia para la salud pública por sus efectos en la calidad de vida de las personas, particularmente de los niños expuestos. La presente investigación fue de tipo descriptivo transversal y se realizó con la finalidad de determinar los niveles de plomo sanguíneo en los habitantes del Centro Poblado de Taca, durante los meses de junio y julio de 2013. Participaron del estudio 42 personas voluntarias: 32 varones y 10 mujeres, cuya media de edad fue de 33,23 años (rango: 21-72 años). Se tomaron muestras de sangre mediante venopunción previo consentimiento informado, utilizando tubos al vacío con anticoagulante, se mantuvieron bajo refrigeración a 8 °C, se trataron con mezcla sulfonítrica - ácido nítrico concentrado a ebullición lenta en un equipo de digestión y luego leídas en un espectrofotómetro de absorción atómica Thermo Scientific ¡CE 3300 a 217 nm. Se obtuvieron los siguientes resultados: todos los sujetos estudiados presentan algún grado de contaminación con plomo, encontrándose un nivel de plumbemia medio de 26,62 ug/dl y los niveles de plomo en sangre de varones y mujeres de 18 a 72 años de edad, encontrándose medias de 33,96 y 3,16 ug/dl, respectivamente, existiendo relación entre el género y plumbemia (p<0,05). El nivel de plomo en sangre de los habitantes del Centro Poblado de Taca, Distrito Canaria, Provincia de Víctor Fajardo, se incrementa en función del tiempo de residencia, por lo que existe relación entre estas dos variables (P<0,05)
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Case studies of the wind field around Ny-Ålesund, Svalbard, using unmanned aircraft
The wind field in Arctic fjords is strongly influenced by glaciers, local orography and the interaction between sea and land. Ny-Ålesund, an important location for atmospheric research in the Arctic, is located in Kongsfjorden, a fjord with a complex local wind field that influences measurements in Ny-Ålesund. Using wind measurements from UAS (unmanned aircraft systems), ground measurements, radiosonde and reanalysis data, characteristic processes that determine the wind field around Ny-Ålesund are identified and analysed. UAS measurements and ground measurements show, as did previous studies, a south-east flow along Kongsfjorden, dominating the wind conditions in Ny-Ålesund. The wind measured by the UAS in a valley 1 km west of Ny-Ålesund differs from the wind measured at the ground in Ny-Ålesund. In this valley, we identify a small-scale catabatic flow from the south to south-west as the cause for this difference. Case studies show a backing (counterclockwise rotation with increasing altitude) of the wind direction close to the ground. A katabatic flow is measured near the ground, with a horizontal wind speed up to 5 m s-1. Both the larger-scale south-east flow along the fjord and the local katabatic flows lead to a highly variable wind field, so ground measurements and weather models alone give an incomplete picture. The comparison of UAS measurements, ground measurements and weather conditions analysis using a synoptic model is used to show that the effects measured in the case studies play a role in the Ny-Ålesund wind field in spring
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