1,849 research outputs found
Development of multisensory spatial integration and perception in humans
Previous studies have shown that adults respond faster and more reliably to bimodal compared to unimodal localization cues. The current study investigated for the first time the development of audiovisual (AâV) integration in spatial localization behavior in infants between 1 and 10 months of age. We observed infantsâ head and eye movements in response to auditory, visual, or both kinds of stimuli presented either 25° or 45° to the right or left of midline. Infants under 8 months of age intermittently showed response latencies significantly faster toward audiovisual targets than toward either auditory or visual targets alone They did so, however, without exhibiting a reliable violation of the Race Model, suggesting that probability summation alone could explain the faster bimodal response. In contrast, infants between 8 and 10 months of age exhibited bimodal response latencies significantly faster than unimodal latencies for both eccentricity conditions and their latencies violated the Race Model at 25° eccentricity. In addition to this main finding, we found ageâdependent eccentricity and modality effects on response latencies. Together, these findings suggest that audiovisual integration emerges late in the first year of life and are consistent with neurophysiological findings from multisensory sites in the superior colliculus of infant monkeys showing that multisensory enhancement of responsiveness is not present at birth but emerges later in life
Generation of Distal Airway Epithelium from Multipotent Human Foregut Stem Cells.
Collectively, lung diseases are one of the largest causes of premature death worldwide and represent a major focus in the field of regenerative medicine. Despite significant progress, only few stem cell platforms are currently available for cell-based therapy, disease modeling, and drug screening in the context of pulmonary disorders. Human foregut stem cells (hFSCs) represent an advantageous progenitor cell type that can be used to amplify large quantities of cells for regenerative medicine applications and can be derived from any human pluripotent stem cell line. Here, we further demonstrate the application of hFSCs by generating a near homogeneous population of early pulmonary endoderm cells coexpressing NKX2.1 and FOXP2. These progenitors are then able to form cells that are representative of distal airway epithelium that express NKX2.1, GATA6, and cystic fibrosis transmembrane conductance regulator (CFTR) and secrete SFTPC. This culture system can be applied to hFSCs carrying the CFTR mutation Îf508, enabling the development of an in vitro model for cystic fibrosis. This platform is compatible with drug screening and functional validations of small molecules, which can reverse the phenotype associated with CFTR mutation. This is the first demonstration that multipotent endoderm stem cells can differentiate not only into both liver and pancreatic cells but also into lung endoderm. Furthermore, our study establishes a new approach for the generation of functional lung cells that can be used for disease modeling as well as for drug screening and the study of lung development.This work was funded by the ERC starting grant Relieve IMDs (L.V.), the Cambridge Hospitals National Institute for Health Research Biomedical Research Center (L.V., N.R.F.H.), and the Evelyn trust (N.R.F.H.). N.A.H. is a Wellcome Trust senior clinical fellow (WT088566, WT097820). F.S. has been funded by an ACT Clinical Research Training Fellowship and a joint Sparks-MRC Clinical Research Training Fellowship. C.-P.S. is funded by the Children's Liver Diseases Foundation.This is the final version of the article. It first appeared from Mary Ann Liebert Publishers via http://dx.doi.org/10.1089/scd.2014.051
Development of multisensory spatial integration and perception in humans
Previous studies have shown that adults respond faster and more reliably to bimodal compared to unimodal localization cues. The current study investigated for the first time the development of audiovisual (AâV) integration in spatial localization behavior in infants between 1 and 10 months of age. We observed infantsâ head and eye movements in response to auditory, visual, or both kinds of stimuli presented either 25° or 45° to the right or left of midline. Infants under 8 months of age intermittently showed response latencies significantly faster toward audiovisual targets than toward either auditory or visual targets alone They did so, however, without exhibiting a reliable violation of the Race Model, suggesting that probability summation alone could explain the faster bimodal response. In contrast, infants between 8 and 10 months of age exhibited bimodal response latencies significantly faster than unimodal latencies for both eccentricity conditions and their latencies violated the Race Model at 25° eccentricity. In addition to this main finding, we found ageâdependent eccentricity and modality effects on response latencies. Together, these findings suggest that audiovisual integration emerges late in the first year of life and are consistent with neurophysiological findings from multisensory sites in the superior colliculus of infant monkeys showing that multisensory enhancement of responsiveness is not present at birth but emerges later in life
A principled approach to programming with nested types in Haskell
Initial algebra semantics is one of the cornerstones of the theory of modern functional programming languages. For each inductive data type, it provides a Church encoding for that type, a build combinator which constructs data of that type, a fold combinator which encapsulates structured recursion over data of that type, and a fold/build rule which optimises modular programs by eliminating from them data constructed using the buildcombinator, and immediately consumed using the foldcombinator, for that type. It has long been thought that initial algebra semantics is not expressive enough to provide a similar foundation for programming with nested types in Haskell. Specifically, the standard folds derived from initial algebra semantics have been considered too weak to capture commonly occurring patterns of recursion over data of nested types in Haskell, and no build combinators or fold/build rules have until now been defined for nested types. This paper shows that standard folds are, in fact, sufficiently expressive for programming with nested types in Haskell. It also defines buildcombinators and fold/build fusion rules for nested types. It thus shows how initial algebra semantics provides a principled, expressive, and elegant foundation for programming with nested types in Haskell
Differential gene expression in abdomens of the malaria vector mosquito, Anopheles gambiae, after sugar feeding, blood feeding and Plasmodium berghei infection
BACKGROUND: Large scale sequencing of cDNA libraries can provide profiles of genes expressed in an organism under defined biological and environmental circumstances. We have analyzed sequences of 4541 Expressed Sequence Tags (ESTs) from 3 different cDNA libraries created from abdomens from Plasmodium infection-susceptible adult female Anopheles gambiae. These libraries were made from sugar fed (S), rat blood fed (RB), and P. berghei-infected (IRB) mosquitoes at 30 hours after the blood meal, when most parasites would be transforming ookinetes or very early oocysts. RESULTS: The S, RB and IRB libraries contained 1727, 1145 and 1669 high quality ESTs, respectively, averaging 455 nucleotides (nt) in length. They assembled into 1975 consensus sequences â 567 contigs and 1408 singletons. Functional annotation was performed to annotate probable molecular functions of the gene products and the biological processes in which they function. Genes represented at high frequency in one or more of the libraries were subjected to digital Northern analysis and results on expression of 5 verified by qRT-PCR. CONCLUSION: 13% of the 1965 ESTs showing identity to the A. gambiae genome sequence represent novel genes. These, together with untranslated regions (UTR) present on many of the ESTs, will inform further genome annotation. We have identified 23 genes encoding products likely to be involved in regulating the cellular oxidative environment and 25 insect immunity genes. We also identified 25 genes as being up or down regulated following blood feeding and/or feeding with P. berghei infected blood relative to their expression levels in sugar fed females
Swift Observations of GRB 050603: An afterglow with a steep late time decay slope
We report the results of Swift observations of the Gamma Ray Burst GRB
050603. With a V magnitude V=18.2 about 10 hours after the burst the optical
afterglow was the brightest so far detected by Swift and one of the brightest
optical afterglows ever seen. The Burst Alert Telescope (BAT) light curves show
three fast-rise-exponential-decay spikes with =12s and a fluence of
7.6 ergs cm in the 15-150 keV band. With an ergs it was also one of the most energetic
bursts of all times. The Swift spacecraft began observing of the afterglow with
the narrow-field instruments about 10 hours after the detection of the burst.
The burst was bright enough to be detected by the Swift UV/Optical telescope
(UVOT) for almost 3 days and by the X-ray Telescope (XRT) for a week after the
burst. The X-ray light curve shows a rapidly fading afterglow with a decay
index =1.76. The X-ray energy spectral index was
=0.71\plm0.10 with the column density in agreement with the
Galactic value. The spectral analysis does not show an obvious change in the
X-ray spectral slope over time. The optical UVOT light curve decays with a
slope of =1.8\plm0.2.
The steepness and the similarity of the optical and X-ray decay rates suggest
that the afterglow was observed after the jet break. We estimate a jet opening
angle of about 1-2Comment: 14 pages, accepted for publication in Ap
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Pain Research Forum: application of scientific social media frameworks in neuroscience
Background: Social media has the potential to accelerate the pace of biomedical research through online collaboration, discussions, and faster sharing of information. Focused web-based scientific social collaboratories such as the Alzheimer Research Forum have been successful in engaging scientists in open discussions of the latest research and identifying gaps in knowledge. However, until recently, tools to rapidly create such communities and provide high-bandwidth information exchange between collaboratories in related fields did not exist. Methods: We have addressed this need by constructing a reusable framework to build online biomedical communities, based on Drupal, an open-source content management system. The framework incorporates elements of Semantic Web technology combined with social media. Here we present, as an exemplar of a web community built on our framework, the Pain Research Forum (PRF) (http://painresearchforum.org). PRF is a community of chronic pain researchers, established with the goal of fostering collaboration and communication among pain researchers. Results: Launched in 2011, PRF has over 1300 registered members with permission to submit content. It currently hosts over 150 topical news articles on research; more than 30 active or archived forum discussions and journal club features; a webinar series; an editor-curated weekly updated listing of relevant papers; and several other resources for the pain research community. All content is licensed for reuse under a Creative Commons license; the software is freely available. The framework was reused to develop other sites, notably the Multiple Sclerosis Discovery Forum (http://msdiscovery.org) and StemBook (http://stembook.org). Discussion: Web-based collaboratories are a crucial integrative tool supporting rapid information transmission and translation in several important research areas. In this article, we discuss the success factors, lessons learned, and ongoing challenges in using PRF as a driving force to develop tools for online collaboration in neuroscience. We also indicate ways these tools can be applied to other areas and uses
Confidence does not mediate a relationship between owner experience and likelihood of using weight management approaches for native ponies
Funding: This study was funded by Mars Petcare and is part of a PhD studentship funded by the Scottish Funding Council Research Excellence Grant (REG). Authors WR and MN receive salary support from the Rural and Environment Science and Analytical Services Division (RESAS). With the exception of PH (employed by the funding organization), the funding organization did not have any additional role in the conceptualization, methodology, investigation, data curation, formal analysis, decision to publish, or preparation of the manuscript. PH was involved in study design, data interpretation, and manuscript preparation.Peer reviewedPublisher PD
GRB 060313: A New Paradigm for Short-Hard Bursts?
We report the simultaneous observations of the prompt emission in the
gamma-ray and hard X-ray bands by the Swift-BAT and the KONUS-Wind instruments
of the short-hard burst, GRB 060313. The observations reveal multiple peaks in
both the gamma-ray and hard X-ray bands suggesting a highly variable outflow
from the central explosion. We also describe the early-time observations of the
X-ray and UV/Optical afterglows by the Swift XRT and UVOT instruments. The
combination of the X-ray and UV/Optical observations provide the most
comprehensive lightcurves to date of a short-hard burst at such an early epoch.
The afterglows exhibit complex structure with different decay indices and
flaring. This behavior can be explained by the combination of a structured jet,
radiative loss of energy, and decreasing microphysics parameters occurring in a
circum-burst medium with densities varying by a factor of approximately two on
a length scale of 10^17 cm. These density variations are normally associated
with the environment of a massive star and inhomogeneities in its windy medium.
However, the mean density of the observed medium (n approximately 10^−4
cm^3) is much less than that expected for a massive star. Although the collapse
of a massive star as the origin of GRB 060313 is unlikely, the merger of a
compact binary also poses problems for explaining the behavior of this burst.
Two possible suggestions for explaining this scenario are: some short bursts
may arise from a mechanism that does not invoke the conventional compact binary
model, or soft late-time central engine activity is producing UV/optical but no
X-ray flaring.Comment: 28 pages, 6 figures. Accepted for publication in ApJ. Clarifications
made and typos correcte
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