21,057 research outputs found
Neonatal lupus with atypical cardiac and cutaneous manifestation
Neonatal lupus erythematosus is a rare, passively acquired autoimmune disease, caused by maternal autoantibodies. The most common manifestations are skin rash and congenital heart block. Cutaneous manifestations may be present at birth, but often develop within a few weeks after delivery. Congenital heart block may present as bradycardia in utero or during physical examination at birth. Approximately 40-60% of mothers are asymptomatic when the infants are diagnosed. We present a case of a child, born with erythematosus lesions in the face, scalp, trunk, limbs and nodules/papules on the palmar and plantar surfaces. He also had hepatosplenomegaly and thrombocytopenia. Echocardiography showed hyperechoic lesions on the anterior papilar muscle of the left ventricle and on the lateral cusp of the tricuspid valve. The mother had unexplained fever and vasculitic lesions in her hands and feet. Antinuclear antibodies, anti-SSa/Ro and anti-SSb/La were positive in the mother and child, making the diagnosis of neonatal lupus
Roles of Education and IQ in Cognitive Reserve in Parkinson's Disease-Mild Cognitive Impairment.
Background/aimsThe role of cognitive reserve in Parkinson's disease (PD)-mild cognitive impairment (MCI) is incompletely understood.MethodsThe relationships between PD-MCI, years of education, and estimated premorbid IQ were examined in 119 consecutive non-demented PD patients using logistic regression models.ResultsHigher education and IQ were associated with reduced odds of PD-MCI in univariate analysis. In multivariable analysis, a higher IQ was associated with a significantly decreased odds of PD-MCI, but education was not.ConclusionThe association of higher IQ and decreased odds of PD-MCI supports a role for cognitive reserve in PD, but further studies are needed to clarify the interaction of IQ and education and the impact of other contributors such as employment and hobbies
Spike sorting for large, dense electrode arrays
Developments in microfabrication technology have enabled the production of neural electrode arrays with hundreds of closely spaced recording sites, and electrodes with thousands of sites are under development. These probes in principle allow the simultaneous recording of very large numbers of neurons. However, use of this technology requires the development of techniques for decoding the spike times of the recorded neurons from the raw data captured from the probes. Here we present a set of tools to solve this problem, implemented in a suite of practical, user-friendly, open-source software. We validate these methods on data from the cortex, hippocampus and thalamus of rat, mouse, macaque and marmoset, demonstrating error rates as low as 5%
Phase Structure and Compactness
In order to study the influence of compactness on low-energy properties, we
compare the phase structures of the compact and non-compact two-dimensional
multi-frequency sine-Gordon models. It is shown that the high-energy scaling of
the compact and non-compact models coincides, but their low-energy behaviors
differ. The critical frequency at which the sine-Gordon model
undergoes a topological phase transition is found to be unaffected by the
compactness of the field since it is determined by high-energy scaling laws.
However, the compact two-frequency sine-Gordon model has first and second order
phase transitions determined by the low-energy scaling: we show that these are
absent in the non-compact model.Comment: 21 pages, 5 figures, minor changes, final version, accepted for
publication in JHE
Miro1 Regulates Activity-Driven Positioning of Mitochondria within Astrocytic Processes Apposed to Synapses to Regulate Intracellular Calcium Signaling
It is fast emerging that maintaining mitochondrial function is important for regulating astrocyte function, although the specific mechanisms that govern astrocyte mitochondrial trafficking and positioning remain poorly understood. The mitochondrial Rho-GTPase 1 protein (Miro1) regulates mitochondrial trafficking and detachment from the microtubule transport network to control activity-dependent mitochondrial positioning in neurons. However, whether Miro proteins are important for regulating signaling-dependent mitochondrial dynamics in astrocytic processes remains unclear. Using live-cell confocal microscopy of rat organotypic hippocampal slices, we find that enhancing neuronal activity induces transient mitochondrial remodeling in astrocytes, with a concomitant, transient reduction in mitochondrial trafficking, mediated by elevations in intracellular Ca(2+). Stimulating neuronal activity also induced mitochondrial confinement within astrocytic processes in close proximity to synapses. Furthermore, we show that the Ca(2+)-sensing EF-hand domains of Miro1 are important for regulating mitochondrial trafficking in astrocytes and required for activity-driven mitochondrial confinement near synapses. Additionally, activity-dependent mitochondrial positioning by Miro1 reciprocally regulates the levels of intracellular Ca(2+) in astrocytic processes. Thus, the regulation of intracellular Ca(2+) signaling, dependent on Miro1-mediated mitochondrial positioning, could have important consequences for astrocyte Ca(2+) wave propagation, gliotransmission, and ultimately neuronal function
An integrated atom-photon junction
Photonic chips that integrate guides, switches, gratings and other
components, process vast amounts of information rapidly on a single device. A
new branch of this technology becomes possible if the light is coupled to cold
atoms in a junction of small enough cross section, so that small numbers of
photons interact appreciably with the atoms. Cold atoms are among the most
sensitive of metrological tools and their quantum nature also provides a basis
for new information processing methods. Here we demonstrate a photonic chip
which provides multiple microscopic junctions between atoms and photons. We use
the absorption of light at a junction to reveal the presence of one atom on
average. Conversely, we use the atoms to probe the intensity and polarisation
of the light. Our device paves the way for a new type of chip with
interconnected circuits of atoms and photons.Comment: 5 pages, 4 figure. Submitted to Nature Photonic
Expecting the Unexpected : Measuring Uncertainties in Mobile Robot Path Planning in Dynamic Envionments
Unexpected obstacles pose significant challenges to mobile robot navigation. In this paper we investigate how, based on the assumption that unexpected obstacles really follow patterns that can be exploited, a mobile robot can learn the locations within an environment that are likely to contain obstacles, and so plan optimal paths by avoiding these locations in subsequent navigation tasks. We propose the DUNC (Dynamically Updating Navigational Confidence) method to do this. We evaluate the performance of the DUNC method by comparing it with existing methods in a large number of randomly generated simulated test environments. our evaluations show that, by learning the likely locations of unexpected obstacles, the DUNC method can plan more efficient paths than existing approaches to this problem
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