607 research outputs found
A closer look at visually guided saccades in autism and Asperger\u27s disorder
Motor impairments have been found to be a significant clinical feature associated with autism and Aspergerâs disorder (AD) in addition to core symptoms of communication and social cognition deficits. Motor deficits in high-functioning autism (HFA) and AD may differentiate these disorders, particularly with respect to the role of the cerebellum in motor functioning. Current neuroimaging and behavioural evidence suggests greater disruption of the cerebellum in HFA than AD. Investigations of ocular motor functioning have previously been used in clinical populations to assess the integrity of the cerebellar networks, through examination of saccade accuracy and the integrity of saccade dynamics. Previous investigations of visually guided saccades in HFA and AD have only assessed basic saccade metrics, such as latency, amplitude and gain, as well as peak velocity. We used a simple visually guided saccade paradigm to further characterize the profile of visually guided saccade metrics and dynamics in HFA and AD. It was found that children with HFA, but not AD, were more inaccurate across both small (5°) and large (10°) target amplitudes, and final eye position was hypometric at 10°. These findings suggest greater functional disturbance of the cerebellum in HFA than AD, and suggest fundamental difficulties with visual error monitoring in HFA
Entanglement-assisted quantum low-density parity-check codes
This paper develops a general method for constructing entanglement-assisted
quantum low-density parity-check (LDPC) codes, which is based on combinatorial
design theory. Explicit constructions are given for entanglement-assisted
quantum error-correcting codes (EAQECCs) with many desirable properties. These
properties include the requirement of only one initial entanglement bit, high
error correction performance, high rates, and low decoding complexity. The
proposed method produces infinitely many new codes with a wide variety of
parameters and entanglement requirements. Our framework encompasses various
codes including the previously known entanglement-assisted quantum LDPC codes
having the best error correction performance and many new codes with better
block error rates in simulations over the depolarizing channel. We also
determine important parameters of several well-known classes of quantum and
classical LDPC codes for previously unsettled cases.Comment: 20 pages, 5 figures. Final version appearing in Physical Review
How do women prepare for pregnancy? Preconception experiences of women attending antenatal services and views of health professionals
Copyright: © 2014 Stephenson et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Main objective - To determine the extent to which women plan and prepare for pregnancy.
Methods - Cross-sectional questionnaire survey of pregnant women attending three maternity services in London about knowledge and uptake of preconception care; including a robust measure of pregnancy planning, and phone interviews with a range of health care professionals.
Main results - We recruited 1173/1288 (90%) women, median age of 32 years. 73% had clearly planned their pregnancy, 24% were ambivalent and only 3% of pregnancies were unplanned. 51% of all women and 63% of those with a planned pregnancy took folic acid before pregnancy. 21% of all women reported smoking and 61% reported drinking alcohol in the 3 months before pregnancy; 48% of smokers and 41% of drinkers reduced or stopped before pregnancy. The 51% of all women who reported advice from a health professional before becoming pregnant were more likely to adopt healthier behaviours before pregnancy [adjusted odds ratios for greatest health professional input compared with none were 2.34 (95% confidence interval 1.54â3.54) for taking folic acid and 2.18 (95% CI 1.42â3.36) for adopting a healthier diet before pregnancy]. Interviews with 20 health professionals indicated low awareness of preconception health issues, missed opportunities and confusion about responsibility for delivery of preconception care.
Significance of the findings - Despite a high level of pregnancy planning, awareness of preconception health among women and health professionals is low, and responsibility for providing preconception care is unclear. However, many women are motivated to adopt healthier behaviours in the preconception period, as indicated by halving of reported smoking rates in this study. The link between health professional input and healthy behaviour change before pregnancy is a new finding that should invigorate strategies to improve awareness and uptake of pre-pregnancy health care, and bring wider benefits for public health.Department of Healt
Nanomechanical Detection of Itinerant Electron Spin Flip
Spin is an intrinsically quantum property, characterized by angular momentum.
A change in the spin state is equivalent to a change in the angular momentum or
mechanical torque. This spin-induced torque has been invoked as the intrinsic
mechanism in experiments ranging from the measurements of angular momentum of
photons g-factor of metals and magnetic resonance to the magnetization reversal
in magnetic multi-layers A spin-polarized current introduced into a nonmagnetic
nanowire produces a torque associated with the itinerant electron spin flip.
Here, we report direct measurement of this mechanical torque and itinerant
electron spin polarization in an integrated nanoscale torsion oscillator, which
could yield new information on the itinerancy of the d-band electrons. The
unprecedented torque sensitivity of 10^{-22} N m/ \sqrt{Hz} may enable
applications for spintronics, precision measurements of CP-violating forces,
untwisting of DNA and torque generating molecules.Comment: 14 pages, 4 figures. visit http://nano.bu.edu/ for related paper
Dopamine transporter genotype is associated with a lateralized resistance to distraction during attention selection
Although lateral asymmetries in orienting behavior are evident across species and have been linked to interhemispheric asymmetries in dopamine signaling, the relative contribution of attentional versus motoric processes remains unclear. Here we took a cognitive genetic approach to adjudicate between roles for dopamine in attentional versus response selection. A sample of nonclinical adult humans (N = 518) performed three cognitive tasks (spatial attentional competition, spatial cueing, and flanker tasks) that varied in the degree to which they required participants to resolve attentional or response competition. All participants were genotyped for two putatively functional tandem repeat polymorphisms of the dopamine transporter gene (DAT1; SLC6A3), which are argued to influence the level of available synaptic dopamine and confer risk to disorders of inattention. DAT1 genotype modulated the task-specific effects of the various task-irrelevant stimuli across both the spatial competition and spatial cueing but not flanker tasks. Specifically, compared with individuals carrying one or two copies of the 10-repeat DAT1 allele, individuals without this allele demonstrated an immunity to distraction, such that response times were unaffected by increases in the number of distractor stimuli, particularly when these were presented predominantly in the left hemifield. All three genotype groups exhibited uniform costs of resolving leftward response selection in a standard flanker task. None of these significant effects could be explained by speedâaccuracy trade-offs, suggesting that participants without the 10-repeat allele of the DAT1 tandem repeat polymorphism possess an enhanced attentional ability to suppress task-irrelevant stimuli in the left hemifield
High-Throughput Analysis of Optical Mapping Data Using ElectroMap
Optical mapping is an established technique for high spatio-temporal resolution study of cardiac electrophysiology in multi-cellular preparations. Here we present, in a step-by-step guide, the use of ElectroMap for analysis, quantification, and mapping of high-resolution voltage and calcium datasets acquired by optical mapping. ElectroMap analysis options cover a wide variety of key electrophysiological parameters, and the graphical user interface allows straightforward modification of pre-processing and parameter definitions, making ElectroMap applicable to a wide range of experimental models. We show how built-in pacing frequency detection and signal segmentation allows high-throughput analysis of entire experimental recordings, acute responses, and single beat-to-beat variability. Additionally, ElectroMap incorporates automated multi-beat averaging to improve signal quality of noisy datasets, and here we demonstrate how this feature can help elucidate lectrophysiological changes that might otherwise go undetected when using single beat analysis. Custom modules are included within the software for detailed investigation of conduction, single file analysis, and alternans, as demonstrated here. This software platform can be used to enable and accelerate the processing, analysis, and mapping of complex cardiac electrophysiology
Ivacaftor potentiation of multiple CFTR channels with gating mutations
AbstractBackgroundThe investigational CFTR potentiator ivacaftor (VX-770) increased CFTR channel activity and improved lung function in subjects with CF who have the G551D CFTR gating mutation. The aim of this in vitro study was to determine whether ivacaftor potentiates mutant CFTR with gating defects caused by other CFTR gating mutations.MethodsThe effects of ivacaftor on CFTR channel open probability and chloride transport were tested in electrophysiological studies using Fischer rat thyroid (FRT) cells expressing different CFTR gating mutations.ResultsIvacaftor potentiated multiple mutant CFTR forms with defects in CFTR channel gating. These included the G551D, G178R, S549N, S549R, G551S, G970R, G1244E, S1251N, S1255P and G1349D CFTR gating mutations.ConclusionThese in vitro data suggest that ivacaftor has a similar effect on all CFTR forms with gating defects and support investigation of the potential clinical benefit of ivacaftor in CF patients who have CFTR gating mutations beyond G551D
Predicting COVID-19 infection risk in people who are immunocompromised by antibody testing.
People with blood cancers have an increased risk of severe COVID-19 disease despite booster vaccine doses.1 This group, like other disease groups at increased risk of severe COVID-19, includes individuals with highly heterogeneous immune responses to vaccination.2 Although vaccine response studies and population studies identify similar diseases and treatments associated with increased risk of severe COVID-19, a direct correlation between antibody levels after vaccination and infection risk has been difficult to define. Identification of a laboratory correlate of infection risk would allow doctors and policy makers to target additional COVID-19 treatment or prophylactic efforts to people who are most in need
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