2,423 research outputs found
Potential role of the anterior lateral line in sound localization in toadfish (Opsanus tau)
Author Posting. © The Company of Biologists, 2018. This article is posted here by permission of The Company of Biologists for personal use, not for redistribution. The definitive version was published in Journal of Experimental Biology 221 (2018): jeb180679, doi:10.1242/jeb.180679.Male oyster toadfish (Opsanus tau) acoustically attract females to
nesting sites using a boatwhistle call. The rapid speed of sound
underwater combined with the close proximity of the otolithic organs
makes inner ear interaural time differences an unlikely mechanism to
localize sound. To determine the role that the mechanosensory lateral
line may play in sound localization, microwire electrodes were
bilaterally implanted into the anterior lateral line nerve to record
neural responses to vibrational stimuli. Highest spike rates and
strongest phase-locking occurred at distances close to the fish and
decreased as the stimulus was moved further from the fish. Bilateral
anterior lateral line neuromasts displayed differential directional
sensitivity to incoming vibrational stimuli, which suggests the
potential for the lateral line to be used for sound localization in the
near field. The present study also demonstrates that the spatially
separated neuromasts of the toadfish may provide sufficient time
delays between sensory organs for determining sound localization
cues. Multimodal sensory input processing through both the inner ear
(far field) and lateral line (near field) may allow for effective sound
localization in fish.This study was funded by the National Science Foundation (IOS 1354745 to A.F.M.).
C.A.R. was funded through a Rutherford Discovery Fellowship from the Royal
Society of New Zealand and a Marine Biological Laboratory fellowship.2019-05-2
Molecular epidemiology of domestic and sylvatic Trypanosoma cruzi infection in rural northwestern Argentina
Genetic diversity of Trypanosoma cruzi populations and parasite transmission dynamics have been well documented throughout the Americas, but few studies have been conducted in the Gran Chaco ecoregion, one of the most highly endemic areas for Chagas disease, caused by T. cruzi. In this study, we assessed the distribution of T. cruzi lineages (identified by PCR strategies) in Triatoma infestans, domestic dogs, cats, humans and sylvatic mammals from two neighbouring rural areas with different histories of transmission and vector control in northern Argentina. Lineage II predominated amongst the 99 isolates characterised and lineage I amongst the six isolates obtained from sylvatic mammals. T. cruzi lineage IIe predominated in domestic habitats; it was found in 87% of 54 isolates from Tr. infestans, in 82% of 33 isolates from dogs, and in the four cats found infected. Domestic and sylvatic cycles overlapped in the study area in the late 1980s, when intense domestic transmission occurred, and still overlap marginally. The introduction of T. cruzi from sylvatic into domestic habitats is likely to occur very rarely in the current epidemiological context. The household distribution of T. cruzi lineages showed that Tr. infestans, dogs and cats from a given house compound shared the same parasite lineage in most cases. Based on molecular evidence, this result lends further support to the importance of dogs and cats as domestic reservoir hosts of T. cruzi. We believe that in Argentina, this is the first time that lineage IIc has been isolated from naturally infected domestic dogs and Tr. infestans.Fil: Cardinal, Marta Victoria. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Lauricella, Marta A.. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud “Dr. C.G. Malbrán”. Instituto Nacional de Parasitología “Dr. M. Fatala Chabén”; ArgentinaFil: Ceballos, Leonardo A.. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; ArgentinaFil: Lanati, Leonardo. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; ArgentinaFil: Marcet, Paula Lorena. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Levin, Mariano Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Kitron, Uriel D.. Emory University; Estados UnidosFil: Gurtler, Ricardo Esteban. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Schijman, Alejandro Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentin
Robotic task-specific training of the upper extremity in children with Cerebral Palsy
poster abstractBackground: Cerebral Palsy (CP) affects at least 2 in 1,000 children in the United States. The disorder is non-progressive, yet secondary impairments can worsen over time leading to contracture, decreased strength, increased tone and ultimately, impaired mobility and function. Robotic therapy has been found to have positive outcomes for similar impairments in stroke neuro-recovery, suggesting the need for the application of this technology to CP. Purpose: The purpose of this study was to investigate whether specific upper extremity (UE) robotic training improves UE function in children with CP. Methods: This is an ongoing study currently with 5 children (ages 4-12) with CP that have completed the treatment intervention. Inclusion criteria included a hemiplegic presentation of the UE, a modified Ashworth scale (MAS) score of 2 or less and wrist extension equal to or greater than 0o in the affected arm, and sufficient cognition to attain to a task for 40-60 minutes. Each child participated in 16 total robotic training sessions occurring twice weekly, with each session consisting of 1,040 task-specific reaching movements of the affected arm with real-time impedance control. Pre- and post-testing and a 1-month follow-up were performed for each subject. Clinical outcome measures included active range of motion (AROM), passive range of motion
(PROM), manual muscle tests (MMT), and grip strength, in addition to functional tests including the MAS, adaptive Fugl-Meyer scale, and the Pediatric Evaluation of Disability Inventory (PEDI) assessed by parents. Lastly, spatial-temporal control patterns were collected during each session, allowing for a visual assessment of a child’s progress in refining UE movement patterns to 16 positions across all quadrants. Results: For AROM and PROM, 4 of 5 subjects demonstrated an increase in at least 2 joints by 1-month follow-up. The remaining measurements produced no change or change within the standard error for goniometry (+/- 5o), while no decline was noted in any subjects. Pre-test MMT revealed strength measures ranging from 3/5 to 5/5. By 1-month follow-up, 85% of all measurements were 5/5, with the remaining 15% at 4+/5. For grip strength, 3 of 4 subjects (fifth subject unavailable) doubled their strength by 1-month follow-up, with the last demonstrating symmetry with the unaffected limb. Tone, as measured by MAS, did not appear to be a limiting factor as only 1 child displayed any noticeable tone (MAS of 2) across the measured motions. For the Fugl-Meyer, 4 of 5 subjects improved coordination by more than 2 points by 1- month follow-up, while the fifth maintained throughout the study. Parents reported via the PEDI an overall improvement in performing functional tasks for all children during the study, with 4 of 5 subjects improving by 10 or more points. Lastly, spatial-temporal control patterns showed marked improvement for all subjects by 1-month follow-up. Conclusion: Early results indicate that the application of robotic training to children with CP improved several clinical measures of the affected limb. This likely resulted in increased use of the affected limb, leading to improved functional performance
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Osteomalacia and vitamin D deficiency in a psychiatric rehabilitation unit: case report and survey.
BACKGROUND: Vitamin D deficiency is common and predisposes to many serious diseases, yet often goes unrecognized. FINDINGS: We describe a case of severe vitamin D deficiency with osteomalacia in a patient resident in a psychiatric hospital for more than 35 years, and discuss causes and complications. We assayed the serum 25-hydroxyvitamin D levels of all patients under our care on one old-age psychiatry rehabilitation unit. Ten of twelve (83%) of patients had vitamin D deficiency, and 92% had suboptimal vitamin D levels. Vitamin D status was strongly predicted by dietary supplementation. Of those not on vitamin D supplements, 100% had vitamin D deficiency, with vitamin D levels significantly below those of historical controls. Age, sex, and duration of admission did not predict vitamin D status in this group. CONCLUSION: We advocate vitamin D screening in all patients admitted to psychogeriatric units, and discuss treatment options given the current problems affecting high-dose vitamin D supply to the United Kingdom.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are
Multilayer Pressure Vessel Materials Testing and Analysis
To provide NASA a comprehensive suite of materials strength, fracture toughness and crack growth rate test results for use in remaining life calculations for aging multilayer pressure vessels, Southwest Research Institute (R) (SwRI) was contracted in two phases to obtain relevant material property data from a representative vessel. This report describes Phase 1 of this effort which includes a preliminary material property assessment as well as a fractographic, fracture mechanics and fatigue crack growth analyses of an induced flaw in the outer shell of a representative multilayer vessel that was subjected to cyclic pressure test. SwRI performed this Phase 1 effort under contract to the Digital Wave Corporation in support of their contract to Jacobs ATOM for the NASA Ames Research Center
Decoherence suppression via environment preparation
To protect a quantum system from decoherence due to interaction with its
environment, we investigate the existence of initial states of the environment
allowing for decoherence-free evolution of the system. For models in which a
two-state system interacts with a dynamical environment, we prove that such
states exist if and only if the interaction and self-evolution Hamiltonians
share an eigenstate. If decoherence by state preparation is not possible, we
show that initial states minimizing decoherence result from a delicate
compromise between the environment and interaction dynamics.Comment: 4 pages, 2 figure
Development of learning objectives for neurology in a veterinary curriculum: Part II: Postgraduates
Background:
Specialization in veterinary medicine in Europe is organized through the Colleges of the European Board of Veterinary Specialization. To inform updating of the curriculum for residents of the European College of Veterinary Neurology (ECVN) job analysis was used. Defining job competencies of diploma holders in veterinary neurology can be used as references for curriculum design of resident training. With the support of the diplomates of the ECVN and the members of the European Society of Veterinary Neurology (ESVN) a mixed-method research, including a qualitative search of objectives and quantitative ranking with 149 Likert scale questions and 48 free text questions in 9 categories in a survey was conducted. In addition, opinions of different groups were subjected to statistical analysis and the result compared.
Results:
A return rate of 62% (n = 213/341) was achieved. Of the competencies identified by the Delphi process, 75% objectives were expected to attain expert level; 24% attain advanced level; 1% entry level. In addition, the exercise described the 11 highly ranked competencies, the 3 most frequently seen diseases of the central and peripheral nervous systems and the most frequently used immunosuppressive, antiepileptic and chemotherapeutic drugs.
Conclusion:
The outcomes of this “Delphi job analysis” provide a powerful tool to align the curriculum for ECVN resident training and can be adapted to the required job competencies, based on expectations. The expectation is that for majority of these competencies diplomates should attain an expert level. Besides knowledge and clinical skills, residents and diplomates are expected to demonstrate high standards in teaching and communication. The results of this study will help to create a European curriculum for postgraduate education in veterinary neurology
Unsplittable coverings in the plane
A system of sets forms an {\em -fold covering} of a set if every point
of belongs to at least of its members. A -fold covering is called a
{\em covering}. The problem of splitting multiple coverings into several
coverings was motivated by classical density estimates for {\em sphere
packings} as well as by the {\em planar sensor cover problem}. It has been the
prevailing conjecture for 35 years (settled in many special cases) that for
every plane convex body , there exists a constant such that every
-fold covering of the plane with translates of splits into
coverings. In the present paper, it is proved that this conjecture is false for
the unit disk. The proof can be generalized to construct, for every , an
unsplittable -fold covering of the plane with translates of any open convex
body which has a smooth boundary with everywhere {\em positive curvature}.
Somewhat surprisingly, {\em unbounded} open convex sets do not misbehave,
they satisfy the conjecture: every -fold covering of any region of the plane
by translates of such a set splits into two coverings. To establish this
result, we prove a general coloring theorem for hypergraphs of a special type:
{\em shift-chains}. We also show that there is a constant such that, for
any positive integer , every -fold covering of a region with unit disks
splits into two coverings, provided that every point is covered by {\em at
most} sets
Coherent acoustic vibration of metal nanoshells
Using time-resolved pump-probe spectroscopy we have performed the first
investigation of the vibrational modes of gold nanoshells. The fundamental
isotropic mode launched by a femtosecond pump pulse manifests itself in a
pronounced time-domain modulation of the differential transmission probed at
the frequency of nanoshell surface plasmon resonance. The modulation amplitude
is significantly stronger and the period is longer than in a gold nanoparticle
of the same overall size, in agreement with theoretical calculations. This
distinct acoustical signature of nanoshells provides a new and efficient method
for identifying these versatile nanostructures and for studying their
mechanical and structural properties.Comment: 5 pages, 3 figure
Asymptotic behaviour of estimators of the parameters of nearly unstable INAR(1) models
A sequence of first-order integer-valued autoregressive type (INAR(1))
processes is investigated, where the autoregressive type coefficients converge to 1. It
is shown that the limiting distribution of the joint conditional least squares estimators
for this coefficient and for the mean of the innovation is normal. Consequences
for sequences of Galton{Watson branching processes with unobservable immigration,
where the mean of the offspring distribution converges to 1 (which is the
critical value), are discussed
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