1,868 research outputs found
Book Review: Islam’s Jesus
Zeki Saritoprak, Islam’s Jesus. University of Florida Press, 2014. Pp. 238, $19.95
Modelling the galaxy-halo connection with semi-recurrent neural networks
We present an artificial neural network design in which past and present-day
properties of dark matter halos and their local environment are used to predict
time-resolved star formation histories and stellar metallicity histories of
central and satellite galaxies. Using data from the IllustrisTNG simulations,
we train a TensorFlow-based neural network with two inputs: a standard layer
with static properties of the dark matter halo, such as halo mass and starting
time; and a recurrent layer with variables such as overdensity and halo mass
accretion rate, evaluated at multiple time steps from .
The model successfully reproduces key features of the galaxy halo connection,
such as the stellar-to-halo mass relation, downsizing, and colour bimodality,
for both central and satellite galaxies. We identify mass accretion history as
crucial in determining the geometry of the star formation history and trends
with halo mass such as downsizing, while environmental variables are important
indicators of chemical enrichment. We use these outputs to compute optical
spectral energy distributions, and find that they are well matched to the
equivalent results in IllustrisTNG, recovering observational statistics such as
colour bimodality and mass-magnitude diagrams.Comment: 22 pages, excluding references. 25 figures. Submitted to MNRA
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Roles of estrogen receptor-alpha in mediating life span: the hypothalamic deregulation hypothesis.
In several species caloric restriction (CR) extends life span. In this paper we integrate data from studies on CR and other sources to articulate the hypothalamic deregulation hypothesis by which estrogen receptor-alpha (ER-α) signaling in the hypothalamus and limbic system affects life span under the stress of CR in mammals. ER-α is one of two principal estrogen-binding receptors differentially expressed in the amygdala, hippocampus, and several key hypothalamic nuclei: the arcuate nucleus (ARN), preoptic area (POA), ventromedial nucleus (VMN), antero ventral periventricular nucleus (AVPV), paraventricular nucleus (PVN), supraoptic nucleus (SON), and suprachiasmatic nucleus (SCN). Estradiol signaling via ER-α is essential in basal level functioning of reproductive cycle, sexually receptive behaviors, physiological stress responses, as well as sleep cycle, and other nonsexual behaviors. When an organism is placed under long-term CR, which introduces an external stress to this ER-α signaling, the reduction of ER-α expression is attenuated over time in the hypothalamus. This review paper seeks to characterize the downstream effects of ER-α in the hypothalamus and limbic system that affect normal endocrine functioning
An Appraisal of the Protection of National Minorities under the 1999 Nigerian Constitution: Lessons from Other Jurisdictions
The protection of national minorities is a crucial aspect of most countries’ constitutional law to ensure equal treatment of all citizens regardless of gender, birth or status. However, in Nigeria, such protection remains a mirage rather than reality. The Nigerian political structure is skewed in favor of the major ethnic groups based on demographic and geographic space offering vast opportunities to power and political dominance in an otherwise heterogeneous society. This paper investigated the provisions of the Constitution of the Federal Republic of Nigeria 1999 to protect national minorities. It utilized the doctrinal methodology and comparative approach to examine the efficiency of the different mechanisms put in place to protect national minorities in Nigeria, such as the federal character principle, local government system, National Youth Service Corps scheme and boundary adjustments. The paper also drew comparative lessons from other jurisdictions like South Africa, USA, Brazil, India, and Pakistan to conclude that Nigeria must follow these countries to meet international best practices in the protection of national minorities. Keywords: National minorities, ethnicity, federal character principle, national integration, human right DOI: 10.7176/JLPG/137-04 Publication date:October 31st 202
Sexual orientation and gender-identity in high functioning individuals with autism spectrum disorder.
When compared to typically-developing individuals, individuals with Autism Spectrum Disorder(ASD) demonstrated significantly higher sexual diversity, with higher rates of non-heterosexuality, and reported more gender non-conforming identities. The ASD group reported poorer mental health than typically-developing individuals and belonging to a sexual or gender-diverse group worsened this effect
A Type III protein-RNA toxin-antitoxin system from Bacillus thuringiensis promotes plasmid retention during spore development.
Members of the Bacillus cereus sensu lato group of bacteria often contain multiple large plasmids, including those encoding virulence factors in B. anthracis. Bacillus species can develop into spores in response to stress. During sporulation the genomic content of the cell is heavily compressed, which could result in counterselection of extrachromosomal genomic elements, unless they have robust stabilization and segregation systems. Toxin-antitoxin (TA) systems are near-ubiquitous in prokaryotes and have multiple biological roles, including plasmid stabilization during vegetative growth. Here, we have shown that a Type III TA system, based on an RNA antitoxin and endoribonuclease toxin, from plasmid pAW63 in Bacillus thuringiensis serovar kurstaki HD-73 can dramatically promote plasmid retention in populations undergoing sporulation and germination, and we provide evidence that this occurs through the post-segregational killing of plasmid-free forespores. Our findings show how an extremely common genetic module can be used to ensure plasmid maintenance during stress-induced developmental transitions, with implications for plasmid dynamics in B. cereus s.l. bacteria.This work was supported by a Commonwealth Scholarship from the Commonwealth Scholarships Commission (UK) and Sir Henry Wellcome Postdoctoral fellowship to FLS, and the Biotechnology and Biological Sciences Research Council (UK).
.This is the final version of the article. It first appeared from Taylor & Francis via http://dx.doi.org/10.1080/15476286.2015.107343
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