Valproate-Associated Parkinsonism: A Critical Review of the Literature

Valproate was first approved as an antiepileptic drug in 1962 and has since also become established as a mood stabiliser and as prophylaxis for migraine. In 1979, Lautin published the first description of a valproate-associated extrapyramidal syndrome. Many cases of valproate-associated parkinsonism have subsequently been published, but uncertainties remain concerning its prevalence, risk factors and prognosis. The aim of this paper is to provide a critical review of the existing literature on valproate-associated parkinsonism and to discuss possible mechanisms. Literature databases were searched systematically: we identified a total of 116 patients with valproate-associated parkinsonism published in case reports, case series and systematic analyses. Prevalence rates ranged widely, between 1.4 and 75 % of patients taking valproate. There was great heterogeneity with regard to clinical presentation, age of onset, valproate dose, concomitant conditions and imaging findings. In all patients apart from three, valproate plasma concentrations were within or even below the recommended reference range when the parkinsonism occurred. Parkinsonism was reversible in the majority of patients, although recovery was often prolonged and sometimes incomplete. A dopaminergic deficit was confirmed in three of six patients investigated with dopamine transporter imaging. Seven of 14 patients who were treated with dopaminergic medication had a good response. The quality of the evidence was assessed and probability of causation was examined using the Naranjo score, which ranged from 0 to 7 (median: 5.0). Several pathophysiological mechanisms, including altered gene expression and neurotransmitter signalling, enhanced neurodegeneration or unmasking subclinical dopaminergic degeneration, could theoretically lead to valproate-associated parkinsonism. Further studies are warranted to elucidate this entity and its underlying pathophysiology

Fluka Estimations concerning Obstacles in the LHC Magnets.

The effect of the impact of the full energy LHC proton beam with an object left in the beam pipe is investigated in order to assess the conditions for a superconducting magnet's quench. FLUKA simulations indicate that a quench would happen about 20 m downstream from the impact for a current through the object being several orders of magnitude lower than the nominal beam current. If such a strict current limit (decreasing with increasing obstacle's thickness) is not exceeded in operational conditions, the obstacle might be destroyed without causing any quench, being the vaporization time dependent on its shape and movement. However, any rise of the traversing current above the mentioned limit would result in a beam dump and the obstacle remaining in the machine

Variation in glacier length and ice volume of Rabots Glaciar, Sweden, in response to climate change, 1910–2003

Historical records, photographs, maps and measurements were used to determine changes in the length, geometry and volume of Rabots Glaciar, Sweden, in response to a warming that occurred early in the 20th century

One Hundred Years Later: Stern-Gerlach Experiment and Dimension Witnesses

Inspired by the one-hundredth anniversary of the seminal works of Stern and Gerlach, our contribution is a proposal of how to use their famous experiment in a more contemporary perspective. Our main idea is to re-cast the experiment in the modern language of prepare-and-measure scenarios. By doing so, it is possible to connect geometric and algebraic aspects of the space of states with the physical space. We also discuss possible simulations of the SG experiment as well as some experimental properties of the experiment revealed at the statistical level. Merging a more modern perspective with a paradigmatic experiment, we hope this paper can serve as an entry door for quantum information theory and the foundations of quantum mechanics.Comment: 23 pages, 6 figures. Minor adjustments, according to referee suggestion

Mathematical models of decision processes for dispersing animals

Each chapter in this expository paper considers a mathematical model of an aspect of animal behavior, and how it affects the patterns of movement across and within a landscape. These models are all directly or indirectly related to questions in either Behavioral Ecology or Landscape Ecology, or both. I first learned about Ecologists’ efforts to connect Landscape Ecology with Behavioral Ecology when Dr. Judy Stamps, Emerita of the University of California, Davis, visited the IGERT colloquium at OSU in the Fall of 2008. Landscape Ecology focuses on neighborhoods, groups, and populations of animals and plants, which are all linked together by the process of dispersal. By contrast, Behavioral Ecology focuses on decisions made by individual dispersers – how they forage for food, select mates, and settle in habitat. Stamps ([27], [18], [26]) argues that this last process – the process of habitat selection –was one way to bridge the gap between Landscape Ecology and Behavioral Ecology. To this end, we introduce and develop three individual-based models of dispersal. Most of our efforts have gone into Chapter 1, where we develop a Stochastic Dynamic Pro-gramming model of habitat selection in natally-dispersing brush mice. The individual choices that brush mice make to investigate, return to, and eventually settle in different habitat sites across the landscape are shown to affect their overall patterns of dispersal: the average time spent on this process, the quality of the site achieved by the process, and the length of the refractory period –the time during which an individual will not settle in response to cues from a habitat. In Chapter 2, we consider a challenge offered by Brillinger [3], regarding the simulation of animal movement constrained to a bounded landscape. As an example model of constrained animal motion, we consider a diffusion model constrained to an interval and study its properties and the conditions on them, for example the conditions for ergodicity and the existence of a stationary distribution. Determining these conditions is an important first step if one wants to make any statistical comparison to data from animal movement. Seeley, Visscher, & Passino [22] document a fascinating example of democratic animal behavior. This example is in the swarming behavior of honeybees selecting a new site for a colony which has split off from its home. The process by which they make their decision is highly democratic, and Seeley himself has started employing a version of it in departmental meetings. In Chapter 3, we consider a model to study the efficacy of swarms using a range of methods to distribute and deploy their scouts for search, and with different memory capacities. We are aware of one other simulation model of this behavior [15], which we introduce for the purposes of comparing and contrasting with our own. We present preliminary results, but note that this chapter is included more as a reference point for future work rather than for the presented, preliminary results

A large volume cell for in situ neutron diffraction studies of hydrothermal crystallizations

A hydrothermal cell with 320 ml internal volume has been designed and constructed for in situneutron diffraction studies of hydrothermal crystallizations. The cell design adopts a dumbbell configuration assembled with standard commercial stainless steel components and a zero-scattering Ti–Zr alloy sample compartment. The fluid movement and heat transfer are simply driven by natural convection due to the natural temperature gradient along the fluid path, so that the temperature at the sample compartment can be stably sustained by heating the fluid in the bottom fluid reservoir. The cell can operate at temperatures up to 300 °C and pressures up to 90 bars and is suitable for studying reactions requiring a large volume of hydrothermal fluid to damp out the negative effect from the change of fluid composition during the course of the reactions. The capability of the cell was demonstrated by a hydrothermal phase transformation investigation from leucite (KAlSi2O6) to analcime (NaAlSi2O6⋅H2O) at 210 °C on the high intensity powder diffractometer Wombat in ANSTO. The kinetics of the transformation has been resolved by collecting diffraction patterns every 10 min followed by Rietveld quantitative phase analysis. The classical Avrami/Arrhenius analysis gives an activation energy of 82.3±1.1 kJ mol−1. Estimations of the reaction rate under natural environments by extrapolations agree well with petrological observations

The Impact of Vacuum Gate Valves on the LHC Beam

The LHC vacuum sector valves are located in the straight sections of the LHC ring, and designed to sectorize the LHC vacuum. The valves are interlocked and should trigger a beam dump request if they close on a circulating beam. This report studies the impact on the machine if this request is not made and the valve scrapes the LHC beam halo. Cascade calculations are made using a model of IR7, with several different valve locations, to calculate the downstream energy deposition in superconducting magnet coils and the corresponding signal in beam loss monitors at the quench level. The calculations are done at 7, 5, and 3.5 TeV. It is found that when a downstream magnet reaches the quench level, the neighbouring BLMs see a signal well above the detection threshold. Furthermore, the BLM signal is consistent with the BLM applied threshold settings and a signal is seen in the time domain before the quench level is reached. Therefore the report concludes that the BLMs can see the closing valve and trigger a beam dump before the quench (or damage) level is reached

Variations in air quality of new Ohio dairy facilities with natural ventilation systems

As dairy operations evolve towards larger, concentrated facilities, air quality on and around the dairy farms becomes a concern. Data on air quality in and around large dairy facilities are insufficient and therefore very much needed. In this study, preliminary data on air quality spatial distribution and temporal variations on two new large dairy facilities with naturally ventilated free stall barns and outside manure storage were collected. Concentration of hydrogen sulfide (H2S) and ammonia (NH3) at 12 to 14 locations on each farm were measured in three seasons using portable gas analyzers. Odor samples were collected at odor sources, upwind and downwind locations. Dust was measured using a portable dust mass concentration meter Gas levels inside the dairy buildings at one leeward location were continuously monitored for three days in two seasons. In addition, indoor and outdoor temperature, relative humidity, and air velocity were measured to determine effects of these parameters on air quality. The study found that manure storage ponds have the most effect on air quality during warm and hot seasons. Variations of air quality inside the dairy building were insignificant. Inside the dairy buildings, the average dust mass concentrations range from 0.9 to 1.5 mg m(-3); ammonia 1.4 to 3 ppm, hydrogen sulfide 2 to 32 ppb; and odor concentration 90 to 140 OU m(-3). However at the downwind berm of the manure storage ponds, odor concentration reached 1256 OU/m(3) during the hot weather months. Weather conditions also affected the outdoor dispersion of air emissions. Most of the time, gas levels at 152 m downwind of the barn and manure storage were similar to upwind levels, but on hot and windy days these levels reached a point high enough to raise concerns. Inside the building, the hydrogen sulfide concentrations were not significantly different from hour to hour within a day or from day to day within a season. Although daily variation of mean ammonia concentrations were significantly different, hourly mean ammonia concentrations were not significantly different between morning hours and afternoon hours within any given day