105,873 research outputs found
Ready, set, differentiate!
The expression of E-Cadherin, a protein best known for its role in cell adhesion, regulates the onset of embryonic differentiation
Impact of schizophrenia on anterior and posterior hippocampus during memory for complex scenes.
ObjectivesHippocampal dysfunction has been proposed as a mechanism for memory deficits in schizophrenia. Available evidence suggests that the anterior and posterior hippocampus could be differentially affected. Accordingly, we used fMRI to test the hypothesis that activity in posterior hippocampus is disproportionately reduced in schizophrenia, particularly during spatial memory retrieval.Methods26 healthy participants and 24 patients with schizophrenia from the UC Davis Early Psychosis Program were studied while fMRI was acquired on a 3 Tesla Siemens scanner. During encoding, participants were oriented to critical items through questions about item features (e.g., "Does the lamp have a square shade?") or spatial location (e.g., "Is the lamp on the table next to the couch?"). At test, participants determined whether scenes were changed or unchanged. fMRI analyses contrasted activation in a priori regions of interest (ROI) in anterior and posterior hippocampus during correct recognition of item changes and spatial changes.ResultsAs predicted, patients with schizophrenia exhibited reduced activation in the posterior hippocampus during detection of spatial changes but not during detection of item changes. Unexpectedly, patients exhibited increased activation of anterior hippocampus during detection of item changes. Whole brain analyses revealed reduced fronto-parietal and striatal activation in patients for spatial but not for item change trials.ConclusionsResults suggest a gradient of hippocampal dysfunction in which posterior hippocampus - which is necessary for processing fine-grained spatial relationships - is underactive, and anterior hippocampus - which may process context more globally - is overactive
Brainstem auditory evoked responses in an equine patient population. Part II: foals.
BackgroundReports of the use of brainstem auditory evoked response (BAER) as a diagnostic modality in foals have been limited.Hypothesis/objectivesTo describe BAER findings and associated causes of hearing loss in foals.AnimalsStudy group 18 foals (15 neonatal, 3 nonneonatal), control group (5 neonatal foals).MethodsRetrospective. BAER records from the Clinical Neurophysiology Laboratory were reviewed from the years of 1982 to 2013. Peak latencies, amplitudes, and interpeak intervals were measured when visible. Clinical data were extracted from the medical records. Foals were grouped under disease categories. Descriptive statistics were performed.ResultsTen neonatal foals had complete absence of BAER bilaterally and 5 had findings within reference range. Abnormalities were associated with common neonatal disorders such as sepsis, neonatal encephalopathy, neonatal isoerythrolysis, and prematurity. BAER loss also was observed in foals with specific coat color patterns such as completely or mostly white with blue irides or lavender with pale yellow irides. An American Miniature foal with marked facial deformation also lacked BAER bilaterally. One nonneonatal foal with an intracranial abscess had no detectable BAER peaks bilaterally, and 2 older foals, 1 with presumed equine protozoal myeloencephalitis and the other with progressive scoliosis and ataxia, had BAER within normal limits.Conclusions and clinical importanceIn neonatal foals, BAER deficits commonly are complete and bilateral, and associated with common neonatal disorders and certain coat and eye color patterns. Sepsis, hypoxia, bilirubin toxicity, and prematurity should be investigated as potential causes of auditory loss in neonatal foals
Text 4 Health: Addressing Consumer Health Information Needs via Text Reference Service
This study seeks to provide empirical evidence about how health-related questions are answered in text reference service in order to further the understanding of how to best use texting as a reference service venue to fulfill people’s health information needs. Two hundred health reference transactions from My Info Quest, the first nation-wide collaborative text reference service, were analyzed identify the types of questions, length of transactions, question-answering behavior, and information sources used in the transactions. Findings indicate that texting-based health reference transactions are usually brief, and cover a wide variety of topics. The most popular questions are those seeking general factual information about human body, medical/health conditions, diseases, or medical concepts/jargons. Great variance is discovered among the question-answering behavior, with only a little more than half of the answers containing citation to information sources. The study will inform the practice of health reference service via texting, and help libraries make evidence-based decisions on establishing service policies and procedures, providing training for librarians, and ultimately implementing the service successfully
B-meson Semi-inclusive Decay to Charmonium in NRQCD and X(3872)
The semi-inclusive B-meson decay into spin-singlet D-wave
charmonium, , is studied in nonrelativistic QCD (NRQCD). Both
color-singlet and color-octet contributions are calculated at next-to-leading
order (NLO) in the strong coupling constant . The non-perturbative
long-distance matrix elements are evaluated using operator evolution equations.
It is found that the color-singlet contribution is tiny, while the
color-octet channels make dominant contributions. The estimated branching ratio
is about in the Naive Dimensional
Regularization (NDR) scheme and in the t'Hooft-Veltman
(HV) scheme, with renormalization scale \,GeV. The
scheme-sensitivity of these numerical results is due to cancelation between
and contributions. The -dependence curves
of NLO branching ratios in both schemes are also shown, with varying from
to and the NRQCD factorization or renormalization scale
taken to be . Comparison of the estimated branching ratio
of with the observed branching ratio of
may lead to the conclusion that X(3872) is unlikely to be the
charmonium state .Comment: Version published in PRD, references added, 26 pages, 9 figure
Brainstem auditory evoked responses in an equine patient population: part I--adult horses.
BackgroundBrainstem auditory evoked response has been an underused diagnostic modality in horses as evidenced by few reports on the subject.Hypothesis/objectivesTo describe BAER findings, common clinical signs, and causes of hearing loss in adult horses.AnimalsStudy group, 76 horses; control group, 8 horses.MethodsRetrospective. BAER records from the Clinical Neurophysiology Laboratory were reviewed from the years of 1982 to 2013. Peak latencies, amplitudes, and interpeak intervals were measured when visible. Horses were grouped under disease categories. Descriptive statistics and a posthoc Bonferroni test were performed.ResultsFifty-seven of 76 horses had BAER deficits. There was no breed or sex predisposition, with the exception of American Paint horses diagnosed with congenital sensorineural deafness. Eighty-six percent (n = 49/57) of the horses were younger than 16 years of age. The most common causes of BAER abnormalities were temporohyoid osteoarthropathy (THO, n = 20/20; abnormalities/total), congenital sensorineural deafness in Paint horses (17/17), multifocal brain disease (13/16), and otitis media/interna (4/4). Auditory loss was bilateral and unilateral in 74% (n = 42/57) and 26% (n = 15/57) of the horses, respectively. The most common causes of bilateral auditory loss were sensorineural deafness, THO, and multifocal brain disease whereas THO and otitis were the most common causes of unilateral deficits.Conclusions and clinical importanceAuditory deficits should be investigated in horses with altered behavior, THO, multifocal brain disease, otitis, and in horses with certain coat and eye color patterns. BAER testing is an objective and noninvasive diagnostic modality to assess auditory function in horses
Task-Projected Hyperdimensional Computing for Multi-Task Learning
Brain-inspired Hyperdimensional (HD) computing is an emerging technique for
cognitive tasks in the field of low-power design. As a fast-learning and
energy-efficient computational paradigm, HD computing has shown great success
in many real-world applications. However, an HD model incrementally trained on
multiple tasks suffers from the negative impacts of catastrophic forgetting.
The model forgets the knowledge learned from previous tasks and only focuses on
the current one. To the best of our knowledge, no study has been conducted to
investigate the feasibility of applying multi-task learning to HD computing. In
this paper, we propose Task-Projected Hyperdimensional Computing (TP-HDC) to
make the HD model simultaneously support multiple tasks by exploiting the
redundant dimensionality in the hyperspace. To mitigate the interferences
between different tasks, we project each task into a separate subspace for
learning. Compared with the baseline method, our approach efficiently utilizes
the unused capacity in the hyperspace and shows a 12.8% improvement in averaged
accuracy with negligible memory overhead.Comment: To be published in 16th International Conference on Artificial
Intelligence Applications and Innovation
A paediatric telecardiology service for district hospitals in south-east England: an observational study.
The attached article is a Publisher version of the final published version which may be accessed at the link below. Copyright © 2010 BMJ Publishing Group Ltd & Royal College of Paediatrics and Child Health. All rights reservedOBJECTIVES: To compare caseloads of new patients assessed by paediatric cardiologists face-to-face or during teleconferences, and assess NHS costs for the alternative referral arrangements. DESIGN: Prospective cohort study over 15 months. SETTING: Four district hospitals in south-east England and a London paediatric cardiology centre. PATIENTS: Babies and children. INTERVENTION: A telecardiology service introduced alongside outreach clinics. MEASUREMENTS: Clinical outcomes and mean NHS costs per patient. RESULTS: 266 new patients were studied: 75 had teleconsultations (19 of 42 newborns and 56 of 224 infants and children). Teleconsultation patients generally were younger (49% being under 1 year compared with 32% seen personally (p = 0.025)) and their symptoms were not as severe. A cardiac intervention was undertaken immediately or planned for five telemedicine patients (7%) and 30 conventional patients (16%). However, similar proportions of patients were discharged after being assessed (32% telemedicine and 39% conventional). During scheduled teleconferences the mean duration of time per patient in sessions involving real-time echocardiography was 14.4 min, and 8.5 min in sessions where pre-recorded videos were transmitted. Mean cost comparisons for telemedicine and face-to-face patients over 14-day and 6-month follow-up showed the telecardiology service to be cost-neutral for the three hospitals with infrequently-held outreach clinics (1519 UK pounds vs 1724 UK pounds respectively after 14 days). CONCLUSION: Paediatric cardiology centres with small cadres of specialists are under pressure to cope with ever-expanding caseloads of new patients with suspected anomalies. Innovative use of telecardiology alongside conventional outreach services should suitably, and economically, enhance access to these specialists.The Department of Health and the Charitable Funds Committee of the Royal Brompton and Harefield NHS Trust funded the project
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