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Within this work the impact of contact materials with higher volume resistivity as leaded solder are investigated in terms of comparability of the current conduction through the joint. An approach was developed to experimentally determine the qualitative local current density by magnetic field imaging (MFI) at ribbon-to-ribbon contact samples. The result reveals that the MFI technique on a symmetric sample design allows the evaluation of the current paths in two-dimensional contact areas. Different resistivities of the contact material result in characteristic differences in current distribution through the joint. Low resistive Sn60Pb40-soldererd contacts exhibit localized current injection whereas the tested contact based on electrically conductive adhesives (ECAs) show an extended current flow through the ECA-based contact. A FEM-based simulation model to mimic the used setup was developed and confirmed the results by taking different contact material resistivities into account. For materials with resistivities larger than 1 · 10−3 Ω · cm current injection was found to spread-spatially within the tested contact geometry. Contact material development as well as contact design can benefit from that approach, allowing consumption and material composition optimization. A further advantage is the feasibility of the method to study production failures like inhomogeneous ECA distribution enabling a non-destructive monitoring of process stability and root cause analysis.

Quantifying the variation in behaviour-related genes within and between populations provides insight into how evolutionary processes shape consistent behavioural traits (i.e. personality). Deliberate introductions of non-native species offer opportunities to investigate how such genes differ between native and introduced populations and how polymorphisms in the genes are related to variation in behaviour. Here, we compared the genetic variation of the two 'personality' genes, DRD4 and SERT, between a native (United Kingdom, UK) and an introduced (New Zealand, NZ) population of dunnocks, Prunella modularis. The NZ population showed a significantly lower number of single nucleotide polymorphisms ( SNPs) compared to the UK population. Standardized F'st estimates of the personality genes and neutral microsatellites indicate that selection (anthropogenic and natural) probably occurred during and post the introduction event. Notably, the largest genetic differentiation was found in the intronic regions of the genes. In the NZ population, we also examined the association between polymorphisms in DRD4 and SERT and two highly repeatable behavioural traits: flight-initiation distance and mating status (promiscuous females and cobreeding males). We found 38 significant associations (for different allele effect models) between the two behavioural traits and the studied genes. Further, 22 of the tested associations showed antagonistic allele effects for males and females. Our findings illustrate how introduction events and accompanying ecological changes could influence the genetic diversity of behaviour-related genes. [ABSTRACT FROM AUTHOR]

Norepinephrine acting via β-adrenergic receptors (β-ARs) plays an important role in hippocampal plasticity including the subiculum which is the principal target of CA1 pyramidal cells and which controls information transfer from the hippocampus to other brain regions including the neighboring presubiculum and the entorhinal cortex (EC). Subicular pyramidal cells are classified as regular- (RS) and burst-spiking (BS) cells. Activation of β-ARs at CA1-subiculum synapses induces long-term potentiation (LTP) in burst- but not in RS cells (Wójtowicz et al., 2010). To elucidate seizure-associated disturbances in the norepinephrine-dependent modulation of hippocampal output, we investigated the functional consequences of the β-AR-dependent synaptic plasticity at CA1-subiculum synapses for the transfer of hippocampal output to the parahippocampal region in the pilocarpine model of temporal lobe epilepsy. Using single-cell and multi-channel field recordings in slices, we studied β-AR-mediated changes in the functional connectivity between CA1, the subiculum and its target-structures. We confirm that application of the β-adrenergic agonist isoproterenol induces LTP in subicular BS- but not RS cells. Due to the distinct spatial distribution of RS- and BS cells in the proximo-to-distal axis of the subiculum, in field recordings, LTP was significantly stronger in the distal than in the proximal subiculum. In pilocarpine-treated animals, β-AR-mediated LTP was strongly reduced in the distal subiculum. The attenuated LTP was associated with a disturbed polysynaptic transmission from the CA1, via the subiculum to the presubiculum, but with a preserved transmission to the medial EC. Our findings suggest that synaptic plasticity may influence target-related information flow and that such regulation is disturbed in pilocarpine-treated epileptic rats. [ABSTRACT FROM AUTHOR]

Following childbirth, major depression (postpartum depression) affects approximately 8-12% of new mothers. However, little is known about the pharmacological management of postpartum depression, and no studies to date have assessed differences in treatment response between women with postpartum and nonpostpartum major depression. The authors reviewed the records of 26 women with postpartum major depression and 25 women with major depression unrelated to childbearing (nonpostpartum depression) who presented to them for treatment over a 4-year period. Compared with the nonpostpartum depressed patients, the postpartum depressed women were significantly more likely to present with anxious features. Also, cases of postpartum depression were more severe than cases of nonpostpartum depression. While the postpartum patients were equally as likely to recover (as defined by a Clinical Global Impression score of 1 or 2) compared to the nonpostpartum-depressed patients, their time to response was significantly longer. By 3 weeks of pharmacotherapy, 75% of the nonpostpartum cases had recovered, in contrast to only 36% of the postpartum cases. Further, postpartum patients were significantly more likely to be receiving more than one antidepressant agent at the time of response to treatment. Length of depression prior to treatment did not explain the difference in treatment response. Presence of depressive symptoms during pregnancy and timing of onset of the depression (before vs. after 4 weeks of delivery) did not affect likelihood of treatment response in this sample. Women with postpartum depression appear to be significantly more likely than the nonpostpartum women to present with anxious features, take longer to respond to pharmacotherapy for depression, and require more antidepressant agents at the time of response to treatment. [ABSTRACT FROM AUTHOR]

Multicrystalline standard p-type silicon solar cells, which undergo a potential induced degradation, are investigated by different methods to reveal the cause of the degradation. Microscopic local ohmic shunts are detected by electron-beam-induced current measurements, which correlate with the sodium distribution in the nitride layer close to the Si surface imaged by time-of-flight secondary ion mass spectroscopy. The results are compatible with a model of the formation of a charge double layer on or in the nitride, which inverts the emitter. (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

Introduction: Primary coenzyme Q10 (CoQ10) deficiency, a recessive disorder associated with various defects of CoQ10 biosynthesis and widely varying clinical presentation, is customarily managed by oral Q10 supplementation but the benefit is debated.Methods: To address this question, we mapped individual responses in two patients with COQ8A-related ataxia following coenzyme Q10 supplementation using noninvasive imaging. Metabolic 31phosphorus magnetic resonance spectroscopy imaging (31P-MRSI) and volumetric cerebellar neuroimaging were performed to quantify the individual treatment response in two patients with COQ8A-related ataxia, each compared with eight age- and gender-matched healthy control subjects.Results: Post-treatment change in energy metabolite levels differed in the two patients, with higher energy levels and improved dysarthria and leg coordination in one, and decreased energy levels without clinical benefit in the other.Conclusions: Our results suggest that the cerebellar bioenergetic state may predict treatment response in COQ8A-related ataxia and highlight the potential of pathophysiology-orientated neuroimaging evidence to inform treatment decisions. [ABSTRACT FROM AUTHOR]