Time minimal control of batch reactors

Abstract In this article we consider a control system modelling a batch reactor in which three species X

Surgical management of multilevel lumbar spondylolysis: A case report and review of the literature

AbstractMultilevel lumbar spondylolysis accounts for less than 6% of the cases of lumbar spondylolysis and its treatment, as reported in the literature, has not been consistent. Fewer than ten cases presenting triple lumbar spondylosis have been published. We describe the case of a 33-year-old male presenting bilateral L3, L4, and L5 isthmic lysis with no spondylolisthesis or disc degeneration. The MRI and CT of the lumbar spine were decisive elements in the therapeutic choice and the surgical treatment performed was bilateral L3 and L4 isthmic repair via a combined anterior and posterior L5S1 approach. The clinical and radiological results were good at the last follow-up visit

Gait variability at fast-pace walking speed: A biomarker of mild cognitive impairment?

The interpretation of the increase in stride-to-stride variability of stride time (STV) regarding the evolution of cognitive deficits across the dementia spectrum is matter of debate.The aim of this study was to compare STV at usual and fast-pace walking speeds of MCI patients with that of cognitively healthy individuals (CHI) and Alzheimer\u27s disease (AD) patients with mild dementia, while considering the effects of potential confounders. STV while walking at usual and fast-pace walking speeds was recorded with the GAITRiteA (R) system from 116 older adults (mean age 75.6 +/- 6.5 years; 55.2% female) divided into 3 groups according to their cognitive status (44 CHI, 39 MCI patients and 33 AD patients with mild dementia). The full adjusted multiple linear regression models showed that high STV was associated with slow gait speed at usual-pace walking speed (P=0.002) and with the MCI status at fast-pace walking speed (P=0.015). High STV at fast-pace walking speed was a specific gait disturbance of MCI patients in the sample of studied participants, and thus could be used in the future as a specific biomarker of MCI patients

Physical Conditoins in Orion's Veil II: A Multi-Component Study of the Line of Sight Toward the Trapezium

Orion's Veil is an absorbing screen that lies along the line of sight to the Orion H II region. It consists of two or more layers of gas that must lie within a few parsecs of the Trapezium cluster. Our previous work considered the Veil as a whole and found that the magnetic field dominates the energetics of the gas in at least one component. Here we use high-resolution STIS UV spectra that resolve the two velocity components in absorption and determine the conditions in each. We derive a volume hydrogen density, 21 cm spin temperature, turbulent velocity, and kinetic temperature, for each. We combine these estimates with magnetic field measurements to find that magnetic energy significantly dominates turbulent and thermal energies in one component, while the other component is close to equipartition between turbulent and magnetic energies. We observe molecular hydrogen absorption for highly excited v, J levels that are photoexcited by the stellar continuum, and detect blueshifted S III and P III. These ions must arise from ionized gas between the mostly neutral portions of the Veil and the Trapezium and shields the Veil from ionizing radiation. We find that this layer of ionized gas is also responsible for He I absorption in the Veil, which resolves a 40-year-old debate on the origin of He I absorption towards the Trapezium. Finally, we determine that the ionized and mostly atomic layers of the Veil will collide in less than 85,000 years.Comment: 43 pages, 15 figures, to be published in Ap

Physical Conditions in Orion's Veil

Orion's veil consists of several layers of largely neutral gas lying between us and the main ionizing stars of the Orion nebula. It is visible in 21cm H I absorption and in optical and UV absorption lines of H I and other species. Toward the Trapezium, the veil has two remarkable properties, high magnetic field (~100 microGauss) and a surprising lack of molecular hydrogen given its total hydrogen column density. Here we compute photoionization models of the veil to establish its gas density and its distance from the Trapezium. We use a greatly improved model of the hydrogen molecule that determines level populations in ~1e5 rotational/vibrational levels and provides improved estimates of molecular hydrogen destruction via the Lyman-Werner bands. Our best fit photoionization models place the veil 1-3 pc in front of the star at a density of 1e3-1e4 cubic centimeters. Magnetic energy dominates the energy of non-thermal motions in at least one of the 21cm H I velocity components. Therefore, the veil is the first interstellar environment where magnetic dominance appears to exist. We find that the low ratio of molecular to atomic hydrogen (< 1e-4) is a consequence of high UV flux incident upon the veil due to its proximity to the Trapezium stars and the absence of small grains in the region.Comment: 45 pages, 20 figures, accepted for publication in Ap

Beyond universality: parametrizing ultracold complex-mediated reactions using statistical assumptions

We have calculated accurate quantum reactive and elastic cross-sections for the prototypical barrierless reaction D$^{+}$ + H$_2$($v$=0, $j$=0) using the hyperspherical scattering method. The considered kinetic energy ranges from the ultracold to the Langevin regimes. The availability of accurate results for this system allows to test the quantum theory by Jachymski et al. [Phys. Rev. Lett. 110, 213202 (2013)] in a nonuniversal case. The short range reaction probability is rationalized using statistical model assumptions and related to a statistical factor. This provides a means to estimate one of the parameters that characterizes ultracold processes from first principles. Possible limitations of the statistical model are considered

Aggressive behavior after traumatic brain injury

INTRODUCTION: In cases of agitation and aggressive behavior after severe traumatic brain injury (TBI), the benefits/risks ratio of pharmacological treatments remains unclear. A qualitative analysis of clinical situations could highlight the relevance of psychotherapy care.CASE REPORT: In January 2005, this 24-year-old patient sustained severe traumatic brain injury (Glasgow at 4/15), with bilateral frontotemporal injury and temporal extradural hematoma. On the third day, a temporal lobectomy was performed. The patient\u27s evolution showed severe neurobehavioral disorders, with agitation and aggressive behavior towards family members and medical caregivers. Maximum doses of antipsychotic drugs brought no improvement. Antidepressant medication improved social contact. Several stays in the psychiatric unit, where institutionalized and psychotherapy care were implemented, showed systematically a real improvement of the behavioral disorders, increased participation in group activities and the ability to walk around alone in a closed environment. DISCUSSION/CONCLUSION: Aggressive behavior can unveil organic brain injuries, depressive syndrome as well as iatrogenic nature of the environment. This clinical case is based on the fact that antipsychotic drugs, aside from their sedative effect, are not the proper treatment for agitation following traumatic brain injury. This case also highlights how management of behavioral disorders following TBI should not be based on pharmacological treatments only but instead should focus on multidisciplinary strategies of care