9,676 research outputs found
Genome editing in non-model organisms opens new horizons for comparative physiology
For almost 100â
years, biologists have made fundamental discoveries using a handful of model organisms that are not representative of the rich diversity found in nature. The advent of CRISPR genome editing now opens up a wide range of new organisms to mechanistic investigation. This increases not only the taxonomic breadth of current research but also the scope of biological problems that are now amenable to study, such as population control of invasive species, management of disease vectors such as mosquitoes, the creation of chimeric animal hosts to grow human organs and even the possibility of resurrecting extinct species such as passenger pigeons and mammoths. Beyond these practical applications, work on non-model organisms enriches our basic understanding of the natural world. This special issue addresses a broad spectrum of biological problems in non-model organisms and highlights the utility of genome editing across levels of complexity from development and physiology to behaviour and evolution
Transition state theory and the dynamics of hard disks
The dynamics of two and five disk systems confined in a square has been
studied using molecular dynamics simulations and compared with the predictions
of transition state theory. We determine the partition functions Z and
Z^\ddagger of transition state theory using a procedure first used by Salsburg
and Wood for the pressure. Our simulations show this procedure and transition
state theory are in excellent agreement with the simulations. A generalization
of the transition state theory to the case of a large number of disks N is made
and shown to be in full agreement with simulations of disks moving in a narrow
channel. The same procedure for hard spheres in three dimensions leads to the
Vogel-Fulcher-Tammann formula for their alpha relaxation time.Comment: 1 new author, new simulations and figures, less speculation. Now 6
pages, 6 figures, 1 animation. Animation may be viewed at
http://www.theory.physics.manchester.ac.uk/~godfrey/supplement/activated_dynamics2.htm
Selective attention to conditioned stimuli in human discrimination learning: Untangling the effect of outcome prediction, valence, arousal and uncertainty
What are the neural mechanisms underlying this ability? Are they the same in humans as in other animals? And what are the consequences of damage to this attentional system? These are the questions that this book aims to answer.The preparation of this manuscript was supported by a MRC new
investigator award to Lee Hogarth (G0701456)
HB 282 - Preservation of Sexual Assault Evidence
This Act extends the time that law enforcement agencies are required to preserve certain evidence of sexual assault. Physical evidence of a reported sexual assault will be preserved for fifty years, and if there is an arrest, for thirty years from the date of arrest or seven years from the sentenceâs completion
Multi-wavelength constraints on cosmic-ray leptons in the Galaxy
Cosmic rays (CRs) interact with the gas, the radiation field and the magnetic
field in the Milky Way, producing diffuse emission from radio to gamma rays.
Observations of this diffuse emission and comparison with detailed predictions
are powerful tools to unveil the CR properties and to study CR propagation. We
present various GALPROP CR propagation scenarios based on current CR
measurements. The predicted synchrotron emission is compared to radio surveys,
and synchrotron temperature maps from WMAP and Planck, while the predicted
interstellar gamma-ray emission is compared to Fermi-LAT observations. We show
how multi-wavelength observations of the Galactic diffuse emission can be used
to help constrain the CR lepton spectrum and propagation. Finally we discuss
how radio and microwave data could be used in understanding the diffuse
Galactic gamma-ray emission observed with Fermi-LAT, especially at low
energies.Comment: 8 pages, 5 figures; in Proceedings of the 34th International Cosmic
Ray Conference (ICRC 2015), The Hague (The Netherlands); Oral contributio
ALMA observations of 99 GHz free-free and H40 line emission from star formation in the centre of NGC 253
We present Atacama Large Millimeter/submillimeter Array observations of 99.02
GHz free-free and H40 emission from the centre of the nearby starburst
galaxy NGC 253. We calculate electron temperatures of 3700-4500 K for the
photoionized gas, which agrees with previous measurements. We measure a
photoionizing photon production rate of s and
a star formation rate of M yr within the central
2010 arcsec, which fall within the broad range of measurements from
previous millimetre and radio observations but which are better constrained. We
also demonstrate that the dust opacities are ~3 dex higher than inferred from
previous near-infrared data, which illustrates the benefits of using millimetre
star formation tracers in very dusty sources.Comment: 5 pages, 3 figures, accepted for publication in MNRAS Letter
Understanding Perceptual Judgment in Autism Spectrum Disorder Using the Drift Diffusion Model
Objective: Two-alternative forced-choice tasks are widely used to gain insight into specific areas of enhancement or impairment in individuals with autism spectrum disorder (ASD). Data arising from these tasks have been used to support myriad theories regarding the integrity, or otherwise, of particular brain areas or cognitive processes in ASD. The drift diffusion model (DDM) provides an account of the underlying processes which give rise to accuracy and reaction time (RT) distributions, and parameterizes these processes in terms which have direct psychological interpretation. Importantly, the DDM provides further insight into the origin of potential group differences in task performance. Here, for the first time, we used the DDM to investigate perceptual decision making in ASD. Method: Adults with (N = 25) and without ASD (N = 32) performed an orientation discrimination task. A drift diffusion model was applied to the full RT distributions. Results: Participants with ASD responded more slowly than controls, the groups did not differ in accuracy. Modeled parameters indicated that: (a) participants with ASD were more cautious than controls (wider boundary separation); (b) nondecision time was increased in ASD; and (c) the quality of evidence extracted from the stimulus (drift rate) did not vary between groups. Conclusions: Taking the behavioral data in isolation would suggest reduced perceptual sensitivity in ASD. However, DDM results indicated that despite response slowing, there was no evidence of differential perceptual sensitivity between participants with and without ASD. Future use of the DDM in investigations of perception and cognition in ASD is highly recommended. (PsycINFO Database Recor
Spitzer 70 Micron Source Counts in GOODS-North
We present ultradeep Spitzer 70 ÎŒm observations of GOODS-North (Great Observatories Origins Deep Survey). For the first time, the turnover in the 70 ÎŒm Euclidean-normalized differential source counts is observed. We derive source counts down to a flux density of 1.2 mJy. From the measured source counts and fluctuation analysis, we estimate a power-law approximation of the faint 70 ÎŒm source counts of dN/dS â S^â1.6, consistent with that observed for the faint 24 ÎŒm sources. An extrapolation of the 70 ÎŒm source counts to zero flux density implies a total extragalactic background light (EBL) of 7.4 ± 1.9 nW m^â2 sr^â1. The source counts above 1.2 mJy account for about 60% of the estimated EBL. From fluctuation analysis, we derive a photometric confusion level of Ïc = 0.30 ± 0.15 mJy (q = 5) for the Spitzer 70 ÎŒm band
IR-correlated 31 GHz radio emission from Orion East
Lynds dark cloud LDN1622 represents one of the best examples of anomalous
dust emission, possibly originating from small spinning dust grains. We present
Cosmic Background Imager (CBI) 31 GHz data of LDN1621, a diffuse dark cloud to
the north of LDN1622 in a region known as Orion East. A broken ring with
diameter g\approx 20 arcmin of diffuse emission is detected at 31 GHz, at
\approx 20-30 mJy beam with an angular resolution of \approx 5 arcmin.
The ring-like structure is highly correlated with Far Infra-Red emission at
m with correlation coefficients of r \approx 0.7-0.8, significant
at . Multi-frequency data are used to place constraints on other
components of emission that could be contributing to the 31 GHz flux. An
analysis of the GB6 survey maps at 4.85 GHz yields a upper limit on
free-free emission of 7.2 mJy beam (\la 30 per cent of the observed
flux) at the CBI resolution. The bulk of the 31 GHz flux therefore appears to
be mostly due to dust radiation. Aperture photometry, at an angular resolution
of 13 arcmin and with an aperture of diameter 30 arcmin, allowed the use of
IRAS maps and the {\it WMAP} 5-year W-band map at 93.5 GHz. A single modified
blackbody model was fitted to the data to estimate the contribution from
thermal dust, which amounts to \sim\sim100 \mu18.1\pm4.4 \mu^{-1}$, consistent with the values found for
LDN1622.Comment: 8 pages, 3 figures, 3 tables, submitted to MNRA
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