2,191 research outputs found
An fMRI study of grammatical morpheme processing associated with nouns and verbs in Chinese
This study examined whether the degree of complexity of a grammatical component in a language would impact on its representation in the brain through identifying the neural correlates of grammatical morpheme processing associated with nouns and verbs in Chinese. In particular, the processing of Chinese nominal classifiers and verbal aspect markers were investigated in a sentence completion task and a grammaticality judgment task to look for converging evidence. The Chinese language constitutes a special case because it has no inflectional morphology per se and a larger classifier than aspect marker inventory, contrary to the pattern of greater verbal than nominal paradigmatic complexity in most European languages. The functional imaging results showed BA47 and left supplementary motor area and superior medial frontal gyrus more strongly activated for classifier processing, and the left posterior middle temporal gyrus more responsive to aspect marker processing. We attributed the activation in the left prefrontal cortex to greater processing complexity during classifier selection, analogous to the accounts put forth for European languages, and the left posterior middle temporal gyrus to more demanding verb semantic processing. The overall findings significantly contribute to cross-linguistic observations of neural substrates underlying processing of grammatical morphemes from an analytic and a classifier language, and thereby deepen our understanding of neurobiology of human language.published_or_final_versio
Simulation of Light Antinucleus-Nucleus Interactions
Creations of light anti-nuclei (anti-deuterium, anti-tritium, anti-He3 and
anti-He4) are observed by collaborations at the LHC and RHIC accelerators. Some
cosmic ray experiments are aimed to find the anti-nuclei in cosmic rays. To
support the experimental studies of the anti-nuclei a Monte Carlo simulation of
anti-nuclei interactions with matter is implemented in the Geant4 toolkit. The
implementation combines practically all known theoretical approaches to the
problem of antinucleon-nucleon interactions.Comment: 8 pages, 5 figure
CD133+ liver cancer stem cells resist interferon-gamma induced autophagy
published_or_final_versio
Cryo-EM structure of a helicase loading intermediate containing ORC-Cdc6-Cdt1-MCM2-7 bound to DNA
In eukaryotes, the Cdt1-bound replicative helicase core MCM2-7 is loaded onto DNA by the ORC-Cdc6 ATPase to form a prereplicative complex (pre-RC) with an MCM2-7 double hexamer encircling DNA. Using purified components in the presence of ATP-γS, we have captured in vitro an intermediate in pre-RC assembly that contains a complex between the ORC-Cdc6 and Cdt1-MCM2-7 heteroheptamers called the OCCM. Cryo-EM studies of this 14-subunit complex reveal that the two separate heptameric complexes are engaged extensively, with the ORC-Cdc6 N-terminal AAA+ domains latching onto the C-terminal AAA+ motor domains of the MCM2-7 hexamer. The conformation of ORC-Cdc6 undergoes a concerted change into a right-handed spiral with helical symmetry that is identical to that of the DNA double helix. The resulting ORC-Cdc6 helicase loader shows a notable structural similarity to the replication factor C clamp loader, suggesting a conserved mechanism of action
Many faces of low mass neutralino dark matter in the unconstrained MSSM, LHC data and new signals
If all strongly interacting sparticles (the squarks and the gluinos) in an
unconstrained minimal supersymmetric standard model (MSSM) are heavier than the
corresponding mass lower limits in the minimal supergravity (mSUGRA) model,
obtained by the current LHC experiments, then the existing data allow a variety
of electroweak (EW) sectors with light sparticles yielding dark matter (DM)
relic density allowed by the WMAP data. Some of the sparticles may lie just
above the existing lower bounds from LEP and lead to many novel DM producing
mechanisms not common in mSUGRA. This is illustrated by revisiting the above
squark-gluino mass limits obtained by the ATLAS Collaboration, with an
unconstrained EW sector with masses not correlated with the strong sector.
Using their selection criteria and the corresponding cross section limits, we
find at the generator level using Pythia, that the changes in the mass limits,
if any, are by at most 10-12% in most scenarios. In some cases, however, the
relaxation of the gluino mass limits are larger (). If a subset of
the strongly interacting sparticles in an unconstrained MSSM are within the
reach of the LHC, then signals sensitive to the EW sector may be obtained. This
is illustrated by simulating the \etslash, , and \etslash signals in i) the light stop scenario and ii) the light
stop-gluino scenario with various light EW sectors allowed by the WMAP data.
Some of the more general models may be realized with non-universal scalar and
gaugino masses.Comment: 27 pages, 1 figure, references added, minor changes in text, to
appear in JHE
Ears of the Armadillo: Global Health Research and Neglected Diseases in Texas
Neglected tropical diseases (NTDs) have\ud
been recently identified as significant public\ud
health problems in Texas and elsewhere in\ud
the American South. A one-day forum on the\ud
landscape of research and development and\ud
the hidden burden of NTDs in Texas\ud
explored the next steps to coordinate advocacy,\ud
public health, and research into a\ud
cogent health policy framework for the\ud
American NTDs. It also highlighted how\ud
U.S.-funded global health research can serve\ud
to combat these health disparities in the\ud
United States, in addition to benefiting\ud
communities abroad
Higgs and non-universal gaugino masses: no SUSY signal expected yet?
So far, no supersymmetric particles have been detected at the Large Hadron
Collider (LHC). However, the recent Higgs results have interesting implications
for the SUSY parameter space. In this paper, we study the consequences of an
LHC Higgs signal for a model with non-universal gaugino masses in the context
of SU(5) unification. The gaugino mass ratios associated with the higher
representations produce viable spectra that are largely inaccessible to the
current LHC and direct dark matter detection experiments. Thus, in light of the
Higgs results, the non-observation of SUSY is no surprise.Comment: supplementary file containing plots with log priors in ancillary
files. v2: added some comments on more general settings and references,
accepted for publication in JHE
Weak pairwise correlations imply strongly correlated network states in a neural population
Biological networks have so many possible states that exhaustive sampling is
impossible. Successful analysis thus depends on simplifying hypotheses, but
experiments on many systems hint that complicated, higher order interactions
among large groups of elements play an important role. In the vertebrate
retina, we show that weak correlations between pairs of neurons coexist with
strongly collective behavior in the responses of ten or more neurons.
Surprisingly, we find that this collective behavior is described quantitatively
by models that capture the observed pairwise correlations but assume no higher
order interactions. These maximum entropy models are equivalent to Ising
models, and predict that larger networks are completely dominated by
correlation effects. This suggests that the neural code has associative or
error-correcting properties, and we provide preliminary evidence for such
behavior. As a first test for the generality of these ideas, we show that
similar results are obtained from networks of cultured cortical neurons.Comment: Full account of work presented at the conference on Computational and
Systems Neuroscience (COSYNE), 17-20 March 2005, in Salt Lake City, Utah
(http://cosyne.org
Effect Of Leptin Status On Neuroendocrine- Reproductive Regulation And Maternal-Fetal Nutrient Transfer In Wistar Albino Rats
Effect of leptin status on neuroendocrine-reproductive regulation in wistar rats was studied. Ten wistar rats weighing between 170-280g were randomly assigned into two study groups. The animals in Group 1 (the control) received a placebo of 5.0ml distilled water while those in Group two were treated with 100mg insulin/kg body weight of rat via gastric intubation. The experiment lasted for 21 days. One day after the final exposure, the animals were euthanized by inhalation of over dose of chloroform. The brain of each rat was harvested and processed into whole homogenate, and was used for some biochemicals assays (i.e isolation and purification of RNA, reverse transcription polymerase chain reaction (PCR), and leptin assay). The results showed that insulin increased the secretion of leptin, which in turn, reduced feed intake, and energy balance, leading to increased MRNA expression, suggesting that leptin may beinvolved in the control of appetite and maturation of luteneizing hormone secretory axis, which may be associated with development of the neuroendocrine axis (i.e neuroendocrine signal transduction). The study may suggest that leptin may serve as effectors that link mechanism that regulate reproduction and energy balance, thus playing an importantrole in reproduction and energy balance; modulating maternal nutrient partitioning inorder to optimize the provision of nutrients for fetal growth
TRY plant trait database - enhanced coverage and open access
Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives
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