466 research outputs found
A Highly Asymmetric Disc-like Mesogen Based on the Tetrabenzotriazaporphyrin Macrocyclic Ring System
Mutant screen reveals the Piccolo's control over depression and brain-gonad crosstalk
Successful sexual reproduction involves a highly complex, genetically encoded interplay between animal physiology and behavior. Here we developed a screen to identify genes essential for rat reproduction based on an unbiased methodology involving mutagenesis via the Sleeping Beauty transposon. As expected, our screen identified genes where reproductive failure was connected to gametogenesis (Btrc, Pan3, Spaca6, Ube2k) and embryogenesis (Alk3, Exoc6b, Slc1a3, Tmx4, Zmynd8). In addition, our screen identified Atg13 (longevity) Dlg1 and Pclo (neuronal disorders), previously not associated with reproduction. Dominant Pclo traits caused epileptiform activity and affected genes supporting GABAergic synaptic transmission (Gabra6, Gabrg3), and animals exhibited a compromised crosstalk between the brain and gonads via disturbed GnRH signaling. Recessive Pclo traits disrupted conspecific recognition required for courtship/mating and were mapped to allelic markers for major depressive disorder (Grm5, Htr2a, Sorcs3, Negr1, Drd2). Thus, Pclo-deficiency in rats link neural networks controlling sexual motivation to Pclo variants that have been associated with human neurological disorders
MgyNi1-y(Hx) thin films deposited by magnetron co-sputtering
In this work we have synthesised thin films of MgyNi1-y(Hx) metal and metal
hydride with y between 0 and 1. The films are deposited by magnetron
co-sputtering of metallic targets of Mg and Ni. Metallic MgyNi1-y films were
deposited with pure Ar plasma while MgyNi1-yHx hydride films were deposited
reactively with 30% H2 in the Ar plasma. The depositions were done with a fixed
substrate carrier, producing films with a spatial gradient in the Mg and Ni
composition. The combinatorial method of co-sputtering gives an insight into
the phase diagram of MgyNi1-y and MgyNi1-yHx, and allows us to investigate
structural, optical and electrical properties of the resulting alloys. Our
results show that reactive sputtering gives direct deposition of metal hydride
films, with high purity in the case of Mg~2NiH~4. We have observed limited
oxidation after several months of exposure to ambient conditions. MgyNi1-y and
MgyNi1-yHx films might be applied for optical control in smart windows, optical
sensors and as a semiconducting material for photovoltaic solar cells
Towards Machine Wald
The past century has seen a steady increase in the need of estimating and
predicting complex systems and making (possibly critical) decisions with
limited information. Although computers have made possible the numerical
evaluation of sophisticated statistical models, these models are still designed
\emph{by humans} because there is currently no known recipe or algorithm for
dividing the design of a statistical model into a sequence of arithmetic
operations. Indeed enabling computers to \emph{think} as \emph{humans} have the
ability to do when faced with uncertainty is challenging in several major ways:
(1) Finding optimal statistical models remains to be formulated as a well posed
problem when information on the system of interest is incomplete and comes in
the form of a complex combination of sample data, partial knowledge of
constitutive relations and a limited description of the distribution of input
random variables. (2) The space of admissible scenarios along with the space of
relevant information, assumptions, and/or beliefs, tend to be infinite
dimensional, whereas calculus on a computer is necessarily discrete and finite.
With this purpose, this paper explores the foundations of a rigorous framework
for the scientific computation of optimal statistical estimators/models and
reviews their connections with Decision Theory, Machine Learning, Bayesian
Inference, Stochastic Optimization, Robust Optimization, Optimal Uncertainty
Quantification and Information Based Complexity.Comment: 37 page
Reconceptualizing informal work practices: Some observations from an ethnic minority community in urban UK
Whilst paid informal work has been conceptualized as a form of paid employment imbued with solely economic motivations, this article critically argues that such a marketâÂoriented reading fails to take into account alternative explanations for the existence of informal work practices. Using evidence from 50 interviews conducted within a Pakistani urban community in a northern UK city, this article, uses a mixedâembeddedness perspective to highlight the importance of predominantly socially and culturally driven motives in the decision to engage in informal work. The findings highlight that participation in informal work, whilst a product of marginalization due to certain institutional and structural factors, is also driven by a range of nonâmonetary motivesâa result of certain socially embedded work relations between ethnic minority workers and their employers. It is this social embeddedness of the employerâemployee relationship in the Pakistani ethnic minority community that explains the continuation of informal work practices in the face of prevailing laws and regulations. The findings add weight to the understanding of informal work as being about more than just economics and constraints, offering these ethnic minority workers opportunities, even status, and giving them agency in an otherwise disempowered situation
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