Phyllobates terribilis

Number of Pages: 5Integrative BiologyGeological Science

Dendrobates leucomelas

Number of Pages: 6Integrative BiologyGeological Science

Intensity Variations of H Alpha and N II 6 583 A Lines in the Night Sky Spectrum

Intensity variations of H alpha and N II 6 583 A lines in night sky spectru

Epigenetic alterations at synaptic plasticity genes in a genetically heterogeneous rat model of neuropsychiatric disorders

Sensorimotor gating impairments are observed across a range of neuropsychiatric conditions. The prepulse inhibition of the acoustic startle response (PPI) is a validated measure of sensorimotor gating. Genetic and pharmacological manipulations in rodents have shown PPI is regulated by specific brain monoaminergic systems. Using genetically heterogeneous NIH-HS rats, we stratified individuals by %PPI. In low PPI animals, we observed elevated mRNA levels of certain neurotransmitter receptors, including metabotropic glutamate receptor Grm2, dopamine receptors Drd1 and Drd2, serotonin receptors Htr1a and Htr2a, and scaffolding protein Homer1, in the frontal cortex (FC) and striatum (STR). We found Drd2 mRNA levels were significantly increased in the low PPI group in STR. Multinomial regression analysis indicated Grm2 in FC and Grm2 and Drd2 in STR predicted PPI group. Additional studies showed a linear relationship between PPI and Grm2 in FC and Drd2 in STR. To explore possible epigenetic regulation of altered gene transcription, we adapted chromatin immunoprecipitation (ChIP) for novel application in frozen brain tissue. We evaluated abundance of acetylated histone H3 (H3ac) and trimethylation of lysine residue 27 of histone H3 (H3K27me3) at regions upstream of gene transcription start sites. No differences in levels of H3ac or H3K27me3 were observed. Studies assessing abundance of other histone modifications are warranted. These efforts may offer insight on how epigenetic modification leads to altered transcription of synaptic plasticity genes regulating sensorimotor gating observed in neuropsychiatric conditions

Variational Monte-Carlo calculation of the nematic state of the two-dimensional electron gas in a magnetic field

We use a Jastrow-Slater wave function with an elliptical Fermi sea to describe the nematic state of the two-dimensional electron gas in a magnetic field and the Monte Carlo method to calculate a variational energy upper bound. These energy upper bounds are compared with other upper bounds describing stripe-ordered ground states which are obtained from optimized Hartree-Fock calculations and with those which correspond to an isotropic ground state. Our findings support the conclusions drawn in our previous study where the Fermi-hypernetted chain approximation was used instead of the Monte Carlo method. Namely, the nematic state becomes energetically favorable relative to the stripe-ordered Wigner crystal phase for the second excited Landau level and below a critical value of the layer ``thickness'' parameter which is very close to its value in the actual materials.Comment: 6 pages, 8 figure

Comparing leadership internationally: challenges and reflections

This paper is a co-written paper by five MA Education students at the University of Northampton and James Underwood, Principal Lecturer at the University of Northampton and a PhD student at the University of Cambridge. We are all currently engaged in research that involves comparing aspects of education in the UK with another nation. The research that we are each personally undertaking addresses a range of topics. These all relate to an aspect of education leadership ranging from student leadership to school and university management. There is one common underlying research question which underpins all the studies which is: in what ways has comparison between nations been a valid approach to understanding education and leadership? This question is addressed successively via our individual stories in this paper. This paper is linked to a paper presented in May 2015 at the University of Cambridge entitled: “Breaking boundaries as writers, researchers and me-searchers, the challenges and rewards of completing an MA as a community of practice.” In which we discussed in depth our experience as a research community. This paper has therefore also been informed by a distinct perspective on the nature of Masters’ level study

Polarized light detection in spiders

Copyright © 2001 The Company of BiologistsWe describe here the detection of polarized light by the simple eyes of spiders. Using behavioural, morphological, electrophysiological and optical studies, we show that spiders have evolved two different mechanisms to resolve the e-vector of light. Wolf spiders (Lycosidae), are able to turn in response to rotation of a polarized pattern at the zenith of their visual fields, and we also describe a strip in the ventral retina of the principal (anterio-median) eyes that views this location and has receptors tiered into two layers. This provides each pair of receptors with a similar optical solution to that provided by the ‘dorsal rim area’ of the insect compound eye. In contrast, gnaphosid spiders have evolved a pair of lensless secondary eyes for the detection of polarized light. These two eyes, each sensitive to orthogonal directions of polarization, are perfectly designed to integrate signals from the larger part of the sky and cooperate to analyse the polarization of light. Built-in polarizers help to improve signal purity. Similar organisation in the eyes of several other spider families suggests that these two mechanisms are not restricted to only a few families.Marie Dacke, Thuy A. Doan and David C. O’Carrol