175 research outputs found
Indirect selection on female extra-pair reproduction? Comparing the additive genetic value of maternal half-sib extra-pair and within-pair offspring
One specific hypothesis explaining the evolution of extra-pair reproduction (EPR) by socially monogamous females is that EPR is under indirect selection because extra-pair offspring (EPO) sired by extra-pair males have higher additive genetic value for fitness than the within-pair offspring (WPO) a female would have produced had she solely mated with her socially paired male. This hypothesis has not been explicitly tested by comparing additive genetic value between EPO and the WPO they replaced. We show that the difference in additive genetic breeding value (BV) between EPO and the WPO they replaced is proportional to the genetic covariance between offspring fitness and male net paternity gain through EPR, and estimate this covariance with respect to offspring recruitment in free-living song sparrows (Melospiza melodia). Recruitment and net paternity gain showed non-zero additive genetic variance and heritability, and negative genetic covariance. Opposite to prediction, EPO therefore had lower BV for recruitment than the WPO they replaced. We thereby demonstrate an explicit quantitative genetic approach to testing the hypothesis that EPR allows polyandrous females to increase offspring additive genetic value, and suggest that there may be weak indirect selection against female EPR through reduced additive genetic value for recruitment of EPO versus WPO in song sparrows
A write time of 6ns for quantum dot–based memory structures
This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Appl. Phys. Lett. 92, 092108 (2008) and may be found at https://doi.org/10.1063/1.2890731.The concept of a memory device based on self-organized quantum dots (QDs) is presented, enabling extremely fast write times, limited only by the charge carrier relaxation time being in the picosecond range. For a first device structure with embedded InAs∕GaAs QDs, a write time of 6ns is demonstrated. A similar structure containing GaSb∕GaAs QDs shows a write time of 14ns. These write times are independent of the localization energy (e.g., storage time) of the charge carriers and at the moment are limited only by the experimental setup and the parasitic cutoff frequency of the low pass of the device.EC/FP6/500101/EU/Self-Assembled semiconductor Nanostructures for new Devices in photonics and Electronics/SANDI
Heritability of female extra-pair paternity rate in song sparrows (Melospiza melodia)
The forces driving the evolution of extra-pair reproduction in socially monogamous animals remain widely debated and unresolved. One key hypothesis is that female extra-pair reproduction evolves through indirect genetic benefits, reflecting increased additive genetic value of extra-pair offspring. Such evolution requires that a female's propensity to produce offspring that are sired by an extra-pair male is heritable. However, additive genetic variance and heritability in female extra-pair paternity (EPP) rate have not been quantified, precluding accurate estimation of the force of indirect selection. Sixteen years of comprehensive paternity and pedigree data from socially monogamous but genetically polygynandrous song sparrows (Melospiza melodia) showed significant additive genetic variance and heritability in the proportion of a female's offspring that was sired by an extra-pair male, constituting major components of the genetic architecture required for extra-pair reproduction to evolve through indirect additive genetic benefits. However, estimated heritabilities were moderately small (0.12 and 0.18 on the observed and underlying latent scales, respectively). The force of selection on extra-pair reproduction through indirect additive genetic benefits may consequently be relatively weak. However, the additive genetic variance and non-zero heritability observed in female EPP rate allow for multiple further genetic mechanisms to drive and constrain mating system evolution
Temperature and electric field dependence of the carrier emission processes in a quantum dot-based memory structure
This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Appl. Phys. Lett. 94, 042108 (2009) and may be found at https://doi.org/10.1063/1.3076126.Hole emission processes from self-organized GaAs0.4Sb0.6/GaAs quantum dots embedded in a - diode are studied by capacitance-voltage spectroscopy. The method introduced allows the investigation of the temperature and electric field dependence of carrier emission with time constants from below nanoseconds up to thousands of seconds. Different emission processes are clearly distinguished, such as tunneling, phonon-assisted tunneling, and thermal activation, each important for quantum-dot-based memory structures. The erase time was determined to 1.5 ms for an electric field of about 200 kV/cm. At 500 kV/cm, 10 ns are predicted sufficient for fast erasing
In vitro evaluation of short-term preserved stallion semen in different doses and temperatures
Tuberculosis of the breast with erythema nodosum: a case report
<p>Abstract</p> <p>Introduction</p> <p>There has been an increasing number of tuberculosis cases worldwide, but tuberculosis of the breast remains rare. In rare cases this is seen with a cutaneous manifestation of erythema nodosum.</p> <p>Case presentation</p> <p>We report the case of a 33-year-old Chinese woman with tuberculosis of the left breast accompanied by erythema nodosum on the anterior aspect of both lower legs. Due to her poor clinical response to conventional therapy, and the histopathological findings of fine needle aspiration cytology, there were strong indications of tuberculosis. Her clinical diagnosis was confirmed by molecular detection of <it>Mycobacterium tuberculosis </it>complex by polymerase chain reaction. The diagnosis was further confirmed by a second polymerase chain reaction test of erythema nodosum which tested positive for <it>Mycobacterium tuberculosis</it> complex. She received anti-tuberculous therapy for 18 months, and finally underwent residual lumpectomy. During her follow-up examination after 12 months, no evidence of either residual or recurrent disease was present.</p> <p>Conclusion</p> <p>Histopathological features and a high index of clinical suspicion are necessary to confirm a diagnosis of tuberculosis of the breast. Anti-tuberculous therapy with or without simple surgical intervention is the core treatment.</p
Deindustrialization in cities of the global south
Recent research by economists has shown that deindustrialization is more severe in Sub-Saharan Africa and Latin America than it ever was in the Organisation for Economic Co-operation and Development (OECD). Nevertheless, most research on deindustrialization is focused on the former centres of Fordist manufacturing in the industrial heartlands of the North Atlantic. In short, there is a mismatch between where deindustrialization is researched and where it is occurring, and the objective of this paper is to shift the geographical focus of research on deindustrialization to the Global South. Case studies from Argentina, India, Tanzania and Turkey demonstrate the variegated nature of deindustrialization beyond the North Atlantic. In the process, it is demonstrated that cities in the Global South can inform wider theoretical discussions on the impacts of deindustrialization at the urban scale
Context specificity of post-error and post-conflict cognitive control adjustments
There has been accumulating evidence that cognitive control can be adaptively regulated by monitoring for processing conflict as an index of online control demands. However, it is not yet known whether top-down control mechanisms respond to processing conflict in a manner specific to the operative task context or confer a more generalized benefit. While previous studies have examined the taskset-specificity of conflict adaptation effects, yielding inconsistent results, controlrelated performance adjustments following errors have been largely overlooked. This gap in the literature underscores recent debate as to whether post-error performance represents a strategic, control-mediated mechanism or a nonstrategic consequence of attentional orienting. In the present study, evidence of generalized control following both high conflict correct trials and errors was explored in a task-switching paradigm. Conflict adaptation effects were not found to generalize across tasksets, despite a shared response set. In contrast, post-error slowing effects were found to extend to the inactive taskset and were predictive of enhanced post-error accuracy. In addition, post-error performance adjustments were found to persist for several trials and across multiple task switches, a finding inconsistent with attentional orienting accounts of post-error slowing. These findings indicate that error-related control adjustments confer a generalized performance benefit and suggest dissociable mechanisms of post-conflict and post-error control. © 2014 Forster, Cho
Plot by plot: plotting urbanism as an ordinary process of urbanization
With this paper, we analyse an ordinary urban process, which has received little attention so far and propose a new concept to take account of it: plotting urbanism. It is usually subsumed
under terms like “urban informality” or “incremental urbanism” and not studied as a distinct process. In comparing Lagos, Istanbul and Shenzhen we captured four defining features of
plotting urbanism: first, it unfolds in a piecemeal fashion with limited comprehensive planning. Second, it emerges from conflicts between multiple overlapping modes of territorial regulation, land tenure and property rights, which result in specific territorial compromises. Third, plotting is based on commodification of housing and land, which might accentuate socio-economic differentiations between property-owners, who often live in the same area, and their tenants. The term “plotting” highlights the key role of the plot in the process. It also alludes to strategic acts of collaboration for individual and collaborative benefit
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