2,957 research outputs found

    Ventricular tachycardia associated with lacosamide co-medication in drug-resistant epilepsy.

    Get PDF
    We report a case of sustained ventricular tachycardia following the initiation of lacosamide as adjunctive epilepsy treatment. A 49-year-old male with intractable frontal lobe seizures experienced severe ventricular tachycardia following the addition of 400 mg lacosamide to his existing regimen of carbamazepine, lamotrigine, clonazepam, and valproate. The tachycardia occurred during a cardiac stress test; stress tests prior to initiation of lacosamide were normal. Conduction defects, including QRS prolongation, persisted during hospitalization until lacosamide was discontinued. The patient had no prior history of cardiac arrhythmia but did possess cardiac risk factors, including hypertension, hypercholesterolemia, and low heart rate variability. This case represents one part of a growing body of literature suggesting a link between arrhythmia and use of lacosamide, which enhances slow inactivation of sodium channels in both the brain and the heart. We believe further study may be necessary to assess the safety of lacosamide in epilepsy patients with cardiac risk factors

    Dispersion Compensation in Acoustic Emission Pipeline Leak Location

    Get PDF
    The general practice of acoustic leak location relies on two different physical phenomena for determining source location: 1) reduction in signal amplitude with increasing distance from the source (attenuation-based methods), and 2) increase in signal transit time with increasing distance from the source (time-of-flight-based methods). The work discussed here describes efforts at ISU directed at gaining first-principle understanding of the underlying physical phenomena of multi-mode dispersion in fluid filled pipes and to developing time-of-flight source location data processing for such dispersive systems. Results are presented for work detailing the characteristics of pipe propagation, as well as the effect of those characteristics on cross-correlation analysis. Theoretical and experimental results are also shown for two approaches which potentially overcome the limitations of cross-correlation techniques

    Diagonalizing operators over continuous fields of C*-algebras

    Full text link
    It is well known that in the commutative case, i.e. for A=C(X)A=C(X) being a commutative C*-algebra, compact selfadjoint operators acting on the Hilbert C*-module HAH_A (= continuous families of such operators K(x)K(x), xXx\in X) can be diagonalized if we pass to a bigger W*-algebra L(X)=AAL^\infty(X)={\bf A} \supset A which can be obtained from AA by completing it with respect to the weak topology. Unlike the "eigenvectors", which have coordinates from A\bf A, the "eigenvalues" are continuous, i.e. lie in the C*-algebra AA. We discuss here the non-commutative analog of this well-known fact. Here the "eigenvalues" are defined not uniquely but in some cases they can also be taken from the initial C*-algebra instead of the bigger W*-algebra. We prove here that such is the case for some continuous fields of real rank zero C*-algebras over a one-dimensional manifold and give an example of a C*-algebra AA for which the "eigenvalues" cannot be chosen from AA, i.e. are discontinuous. The main point of the proof is connected with a problem on almost commuting operators. We prove that for some C*-algebras if hAh\in A is a selfadjoint, uAu\in A is a unitary and if the norm of their commutant [u,h][u,h] is small enough then one can connect uu with the unity by a path u(t)u(t) so that the norm of [u(t),h][u(t),h] would be also small along this path.Comment: 21 pages, LaTeX 2.09, no figure

    The Marine Fishes of Broward County, Florida: Final Report of 1998-2002 Survey Results

    Get PDF
    We inventoried fishes associated with three hardbottom reef tracts that are separated by sand and run parallel to the coast in sequentially deeper water offshore Broward County, Florida. Using SCUBA and the Bohnsack-Bannerot visual point count method, we recorded fish abundance, species richness, sizes (TL), and general habitat characteristics within an imaginary 15m cylinder extending from the substrate to the surface. Sites were sampled along transects at quarter nautical mile intervals along 18 nautical miles of coastline at western and eastern edges, and crest of each of the three reef tracts. A total of 86,463 fishes belonging to 208 species and 52 families was censused from 667 sites over four years (August 1998 to November 2002). Mean species richness, mean total abundance and mean total biomass of fishes increased significantly on each reef tract moving offshore (p Differences were found within reef tracts based on edge or crest sites and position along reefs north or south of Port Everglades and Hillsboro Inlet. Sites within 5 na. mi. south of Port Everglades had lower total abundance and species richness (p Of management interest, was a scarcity or absence of groupers and snappers observed over four years. Although juvenile red grouper were frequently seen (n = 232 at 667 sites), only two were above legal minimum size. No goliath or black grouper were recorded. A total of 10 gag, yellowfin, or scamp grouper was observed; none were legal. Among six snapper species, 219 of 718 were of legal size

    Testing and Improving a UAV-Based System Designed for Wetland Methane Source Measurements

    Get PDF
    Wetlands are the single highest emitting methane source category, but the magnitude of wetland fluxes remains difficult to fully characterize due to their large spatial extent and heterogeneity. Fluxes can vary with land surface conditions, vegetation type, and seasonal changes in environmental conditions. Unmanned aerial vehicles (UAVs) are an emerging platform to better characterize spatial variability in these natural ecosystems. While presenting some advantages over traditional techniques like towers and flux chambers, in that they are mobile vertically and horizontally, their use is still challenging, requiring continued improvement in sensor technology and field measurement approaches. In this work, we employ a small, fast response laser spectrometer on a Matrice 600 hexacopter. The system was previously deployed successfully for 40 flights conducted in a four-day period in 2018 near Fairbanks, Alaska. These flights revealed several potential areas for improvement, including: vertical positioning accuracy, the need for sensor health indicators, and approaches to deal with low wind speeds. An additional set of flights was conducted this year near Antioch in California. Flights were conducted several meters above ground up to 15-25 m in a curtain pattern. These curtains were flown both upwind and downwind of a tower site, allowing us to calculate a mass balance methane flux estimate that can be compared to eddy covariance fluxes from the tower. Testing will better characterize the extent to which altitude drifts in-flight and how GPS values compare with measurements from the onboard LIDAR, as well as the agreement between two-dimensional wind speed and direction on the ground versus measured onboard the UAV. Hardware improvements to the sensor and GPS are being considered to help reduce these sources of uncertainty. Results of this testing and how system performance relates to needs for quantifying wetland fluxes, will be presented

    Characterization of the Marine Fish Assemblage Associated with the Nearshore Hardbottom of Broward County, Florida, USA

    Get PDF
    Some shallow (\u3c7 m, water depth) nearshore hardbottom areas of southeast Florida have been reported to function as important juvenile fish habitat. Much of this area has been impacted by one or more local beach renourishments (sand fill to offset erosion). We characterized the nearshore fish communities and compared the fish assemblages adjacent to renourished beach to those adjacent to never-renourished beach along a 30-km stretch of coastline, primarily in Broward County, using three visual census methods. Two hundred transect-counts, 100 point-counts and 98 rover-diver counts were completed during June–August 2001. In transect- and point-counts, abundance of all fish species and their sizes were recorded; the rover-diver counts consisted of a simple species list. In total, 164 species and over 72,000 fish were recorded. The highest number of species (145) was recorded with the rover-diver counts. The transects-counts had 118 species and 109 species were recorded on the point-counts. With either all the sites adjacent to renourished beach pooled and compared to the pooled never-renourished sites or individual comparisons amongst renourished and neighboring never-renourished sites, no consistent differences were noted in fish abundance or species richness (ANOVA) or among fish assemblage structure (MDS plot of Bray–Curtis dissimilarity indices). However, although the data show no obvious distinct difference between the renourished and never-renourished sites, due to several important confounding factors (e.g., census methodology, longshore movement of sand fill) and the absence of baseline data prior to any renourishment, it would be premature to translate these results into management strategies. The assemblage structure, in terms of percentage of juvenile fish (\u3c5 cm) as well as percent contributions by family, was similar for the point-counts and transect-counts. However, in mean density per m2 of substrate, greater abundance and greater species richness values were recorded with the transect-counts than with the point-counts. Newly settled and early juveniles were the dominant component (\u3e84%) of the inshore fish community, consisting primarily (\u3e90%) of grunts (Haemulidae). After the grunts, the wrasses (Labridae) at about 5%, and damselfish (Pomacentridae) at roughly 2% were the predominant families. It is clear from this study and others that the nearshore hardbottom of Broward County is an important juvenile fish habitat, especially for grunts. However, the nearshore hardbottom does not appear to be obligate habitat for these fishes as fishes associated with this area are, apparently, not unique to the nearshore hardbottom either in species or ontogenic stage

    An intellectual disability syndrome with single nucleotide variants in <i>O-GlcNAc Transferase</i>

    Get PDF
    Contains fulltext : 220584.pdf (Publisher’s version ) (Open Access)Intellectual disability (ID) is a neurodevelopmental condition that affects ~1% of the world population. In total 5-10% of ID cases are due to variants in genes located on the X chromosome. Recently, variants in OGT have been shown to co-segregate with X-linked intellectual disability (XLID) in multiple families. OGT encodes O-GlcNAc transferase (OGT), an essential enzyme that catalyses O-linked glycosylation with β-N-acetylglucosamine (O-GlcNAc) on serine/threonine residues of thousands of nuclear and cytosolic proteins. In this review, we compile the work from the last few years that clearly delineates a new syndromic form of ID, which we propose to classify as a novel Congenital Disorder of Glycosylation (OGT-CDG). We discuss potential hypotheses for the underpinning molecular mechanism(s) that provide impetus for future research studies geared towards informed interventions

    Experimental Demonstration of Post-Selection based Continuous Variable Quantum Key Distribution in the Presence of Gaussian Noise

    Full text link
    In realistic continuous variable quantum key distribution protocols, an eavesdropper may exploit the additional Gaussian noise generated during transmission to mask her presence. We present a theoretical framework for a post-selection based protocol which explicitly takes into account excess Gaussian noise. We derive a quantitative expression of the secret key rates based on the Levitin and Holevo bounds. We experimentally demonstrate that the post-selection based scheme is still secure against both individual and collective Gaussian attacks in the presence of this excess noise.Comment: 4 pages, 4 figure
    corecore