615 research outputs found
When Time Matters: Eastern Europe's Response to Chinese Competition
This paper presents evidence in support of a novel source of comparative advantage that arises from geographic proximity between trading partners and differential importance of timely delivery across industries (i.e. time-sensitivity). To test this channel, we investigate adjustments to Chinese export competition by a group of Eastern and Southeastern European (ESE) countries within EU15 destination-product markets. We rely on instrumental variables to extract exogenous variation in the expansion of Chinese export supply capacity across products and destinations. While finding sizable displacements effects materializing in terms of both export revenues and quantities, they appear to be about 50 percent smaller for time-sensitive exports. We further show that distance between trade partners determines this differential effect. Results based on firm-level customs data for a single ESE country support these findings. Overall, we observe that geographic proximity can shield firms from external competition in specific industries
Plunging into a world? A novel approach to undergraduates’ metaphors of reading
Although there is considerable research on and knowledge about students’ conceptualizations of learning or academic practices and skills, the variability of these conceptualizations has been consistently neglected. In the present study, we address this variability in the field of academic reading with the help of a novel approach. Drawing on qualitative metaphor analysis, we report a detailed system of students’ conceptual metaphors of reading. Our specific methodological approach to identify the structure of these conceptual metaphors allows to analyze subjective agency on a lexical as well as grammatical level. The conceptual metaphors we identified by this method are marÂkedly variable, although they create an overall impression of medium to low agency, that is a reader who is only weakly active or potent. Interrater reliability of the coding system was very good. We also report and analyze the frequency of the conceptual metaphors in a sample of 143 texts written by bachelor students
Conductance matrix symmetries of multiterminal semiconductor-superconductor devices
Nonlocal tunneling spectroscopy of multiterminal semiconductor-superconductor
hybrid devices is a powerful tool to investigate the Andreev bound states below
the parent superconducting gap. We examine how to exploit both microscopic and
geometrical symmetries of the system to extract information on the normal and
Andreev transmission probabilities from the multiterminal electric or
thermoelectric differential conductance matrix under the assumption of an
electrostatic potential landscape independent of the bias voltages, as well as
the absence of leakage currents. These assumptions lead to several symmetry
relations on the conductance matrix. Next, by considering a numerical model of
a proximitized semiconductor wire with spin-orbit coupling and two normal
contacts at its ends, we show how such symmetries can be used to identify the
direction and relative strength of Rashba versus Dresselhaus spin-orbit
coupling. Finally, we study how a voltage-bias-dependent electrostatic
potential as well as quasiparticle leakage break the derived symmetry relations
and investigate characteristic signatures of these two contributions.Comment: 16 pages, 10 figure
Biparental inbreeding depression, genetic relatedness and progeny vigor in a wind-pollinated treeline species in Argentina
Spatially restricted gene flow and resulting spatial genetic structure are generally considered as being the primary controlling factors in the dynamics of biparental inbreeding depression in a wide range of plant species. However, wind-pollinated angiosperm trees have not been adequately studied in this respect. The present study analyses the relationships between parental genetic similarity, outcrossing distances and progeny vigour in Polylepis australis (Rosaceae), a wind-pollinated treeline species endemic to Argentina. We investigated whether spatial genetic structuring occurs in anthropogenically fragmented P. australis woodlands of the Córdoba Mountains. We also performed a controlled crossing experiment using pollen collected from different distances. Genetic variability (using RAPD-PCR) and vigour (survival and N metabolism capacity) of the resulting progeny were contrasted with progeny from unmanipulated flowers. We found a continuous decrease in parental genetic similarity with spatial distance among mates and an increase in genetic variability, survival and N metabolism capacity in the progeny produced from pollen at increasing distances. However, our further results suggest fragment connectivity in P. australis through effective long-distance pollen-mediated gene flow with no effective inbreeding depression problems observed under present day conditions.Fil: Seltmann, Peggy. Martin-Luther-University Halle-Wittenberg; AlemaniaFil: Hensen, Isabell. Martin-Luther-University Halle-Wittenberg; AlemaniaFil: Renison, Daniel. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, FÃsicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; ArgentinaFil: Wesche, Karsten. University of Göttingen; AlemaniaFil: Ploch, Sebastián. University of Hohenheim; AlemaniaFil: Rondan Dueñas, Juan. Universidad Nacional de Córdoba; ArgentinaFil: Cocucci, Andrea Aristides. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de BiologÃa Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas FÃsicas y Naturales. Instituto Multidisciplinario de BiologÃa Vegetal; ArgentinaFil: Jung, Klaus. Helmholtz Centre for Environmental Research-UFZ; Alemani
Comparison of first-line and second-line terlipressin versus sole norepinephrine in fulminant ovine septic shock
The Surviving Sepsis Guidelines suggest the use of vasopressin in case of catecholamine-refractory septic shock. Terlipressin (TP) as a V-1-selective AVP analogue is a potential alternative, though data regarding the first-line administration in septic shock are scarce. The present study explored and compared the effects of first-line vs. second-line infusion of TP or sole norepinephrine regarding organ function, fluid and norepinephrine requirements and survival in fulminant ovine septic shock. Peritoneal sepsis was induced in 23 ewes after laparotomy and faecal withdrawal from the caecum. After onset of shock, causal and supportive sepsis therapy (antibiotics, peritoneal lavage, fluids and open-label norepinephrine) was performed in all animals. Concurrently, animals were randomized to receive 0.9% sodium chloride (control group) or TP (2 mu g.kg(-1).h(-1), first-line group) after shock onset. In the second-line TP group, TP (2 mu g.kg(-1).h(-1)) was started once norepinephrine requirements exceeded 0.5 mu g.kg(-1).min(-1). No significant differences were found between groups regarding survival, haemodynamics as well as fluid-and catecholamine-requirements. Kidney function and electron microscopic kidney injury were comparable between groups. In the present model of fulminant ovine septic shock, first-line TP infusion had no significant effect on fluid and norepinephrine requirements or organ dysfunction as compared to second-line TP infusion or placebo
Rust mite resistance in apple assessed by quantitative trait loci analysis
The aim of this study was to assess the genetic basis of rust mite (Aculus schlechtendali) resistance in apple (Malus × domestica). A. schlechtendali infestation of apple trees has increased as a consequence of reduced side effects of modern fungicides on rust mites. An analysis of quantitative trait loci (QTLs) was carried out using linkage map data available for F1 progeny plants of the cultivars ‘Fiesta' × ‘Discovery'. Apple trees representing 160 different genotypes were surveyed for rust mite infestation, each at three different sites in two consecutive years. The distribution of rust mites on the individual apple genotypes was aggregated and significantly affected by apple genotype and site. We identified two QTLs for A. schlechtendali resistance on linkage group 7 of ‘Fiesta'. The AFLP marker E35M42-0146 (20.2cM) and the RAPD marker AE10-400 (45.8cM) were closest positioned to the QTLs and explained between 11.0% and 16.6% of the phenotypic variability. Additionally, putative QTLs on the ‘Discovery' chromosomes 4, 5 and 8 were detected. The SSR marker Hi03a10 identified to be associated to one of the QTLs (AFLP marker E35M42-0146) was traced back in the ‘Fiesta' pedigree to the apple cultivar ‘Wagener'. This marker may facilitate the breeding of resistant apple cultivars by marker assisted selection. Furthermore, the genetic background of rust mite resistance in existing cultivars can be evaluated by testing them for the identified SSR marke
An easy-to-use microfluidic interconnection system to create quick and reversibly interfaced simple microfluidic devices
QTL analysis for aphid resistance and growth traits in apple
The rosy apple aphid (Dysaphis plantaginea), the leaf-curling aphid (Dysaphis cf. devecta) and the green apple aphid (Aphis pomi) are widespread pest insects that reduce growth of leaves, fruits and shoots in apple (Malus × domestica). Aphid control in apple orchards is generally achieved by insecticides, but alternative management options like growing resistant cultivars are needed for a more sustainable integrated pest management (IPM). A linkage map available for a segregating F1-cross of the apple cultivars ‘Fiesta' and ‘Discovery' was used to investigate the genetic basis of resistance to aphids. Aphid infestation and plant growth characteristics were repeatedly assessed for the same 160 apple genotypes in three different environments and 2 consecutive years. We identified amplified fragment length polymorphism (AFLP) markers linked to quantitative trait loci (QTLs) for resistance to D. plantaginea (‘Fiesta' linkage group 17, locus 57.7, marker E33M35-0269; heritability: 28.3%), and to D. cf. devecta (‘Fiesta' linkage group 7, locus 4.5, marker E32M39-0195; heritability: 50.2%). Interactions between aphid species, differences in climatic conditions and the spatial distribution of aphid infestation were identified as possible factors impeding the detection of QTLs. A pedigree analysis of simple sequence repeat (SSR) marker alleles closely associated with the QTL markers revealed the presence of the alleles in other apple cultivars with reported aphid resistance (‘Wagener', ‘Cox's Orange Pippin'), highlighting the genetic basis and also the potential for gene pyramiding of aphid resistance in apple. Finally, significant QTLs for shoot length and stem diameter were identified, while there was no relationship between aphid resistance and plant trait QTL
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