Functional and anatomic correlates of two frequently observed temporal lobe seizure-onset patterns.

Intracranial depth electrode EEG records of 478 seizures, recorded in 68 patients undergoing diagnostic monitoring with depth electrodes, were evaluated to investigate the correlates of electrographic onset patterns in patients with temporal lobe seizures. The seizure onsets in 78% of these patients were identified as either hypersynchronous onsets, beginning with low-frequency, high-amplitude spikes, or low-voltage fast (LVF) onsets, increasing in amplitude as the seizure progressed. The number of patients (35) having hypersynchronous seizure onsets was nearly twice that of patients (18) having LVF onsets. Three major differences were seen among patients with the two seizure-onset patterns. When compared with patients having LVF onsets, patients with hypersynchronous seizure onsets had a significantly greater probability of having (1) focal rather than regional seizure onsets (p < 0.01), (2) seizures spreading more slowly to the contralateral mesial temporal lobe (p < 0.003), and (3) cell counts in resected hippocampal tissue showing greater neuronal loss (p < 0.001). The results provide evidence that the most frequent electrographic abnormality associated with mesial temporal seizures is local hypersynchrony, a condition associated with major neuronal loss in the hippocampus. The results also indicate that LVF seizure onsets more frequently represent widely distributed discharges, which interact with and spread more rapidly to surrounding neocortical areas

FE analysis and experimental determination of a shaft deflection under three-point loading

Increasing industrial demand for new products including advanced production technology leads to substantial natural resources consumption. Furthermore, huge environmental pollution and emerging environmental legislation motivate the machine tools industry as one of the major resource consumers on a global scale to develop methods for more sustainable use of the Earth's resources. Machine tools re-engineering concerning design and failure analysis is an approach by which outdated machines are upgraded and restored to like-new machines. To evaluate the mechanical failure of the used machine components and to ensure their reliable future performance, it is essential to make material, design, and surface investigations. In this paper, an experimental approach based on the principle of a three-point bending test is presented to evaluate the shaft elastic behavior under loading. Moreover, finite element analysis and numerical integration method are used to determine the maximum linear deflection and bending stress of the shaft. Subsequently, a comparison between the results is made. In conclusion, it was found that the measured bending deflection and stress were well close to the admissible design values. Therefore, the shaft can be used again in the second life cycle. However, based on previous surface tests conducted, the shaft surface needs re-carburizing and refining treatments to ensure the reliable performance of the surface

Vitrification of a monatomic 2D simple liquid

A monatomic simple liquid in two dimensions, where atoms interact isotropically through the Lennard-Jones-Gauss potential [M. Engel and H.-R. Trebin, Phys. Rev. Lett. 98, 225505 (2007)], is vitrified by the use of a rapid cooling technique in a molecular dynamics simulation. Transformation to a crystalline state is investigated at various temperatures and the time-temperature-transformation (TTT) curve is determined. It is found that the transformation time to a crystalline state is the shortest at a temerature 14% below the melting temperature Tm and that at temperatures below Tv = 0.6 Tm the transformation time is much longer than the available CPU time. This indicates that a long-lived glassy state is realized for T < Tv.Comment: 5pages,5figures,accepted for publication in CEJ

Bi-Lateral Changes to Hippocampal Cholesterol Levels During Epileptogenesis and in Chronic Epilepsy Following Focal-Onset Status Epilepticus in Mice

Brain cholesterol homeostasis has been shown to be disrupted in neurodegenerative conditions such as Alzheimer\u27s and Huntington\u27s diseases. Investigations in animal models of seizure-induced brain injury suggest that brain cholesterol levels are altered by prolonged seizures (status epilepticus) and are a feature of the pathophysiology of temporal lobe epilepsy. The present study measured hippocampal sterol levels in a model of unilateral hippocampal injury triggered by focal-onset status epilepticus, and in chronically epileptic mice. Status epilepticus was induced by intra-amygdala microinjection of kainic acid and ipsilateral and contralateral hippocampus analyzed. No significant changes were found for ipsilateral or contralateral hippocampal levels of desmosterol or lathosterol at any time after SE as measured by gas chromatography–mass spectrometry. 24S-hydroxycholesterol and cholesterol levels were unchanged up to 24 h after status epilepticus but were decreased in the ipsilateral hippocampus during early epileptogenesis and in chronically epileptic mice. Levels of cholesterol were also reduced in the contralateral hippocampus during epileptogenesis and in chronic epileptic mice. Treatment of mice with the anti-inflammatory cholesterol synthesis inhibitor lovastatin did not alter seizures during status epilepticus or seizure-induced neuronal death. Thus, changes to hippocampal cholesterol homeostasis predominantly begin during epileptogenesis, occur bi-laterally even when the initial precipitating injury is unilateral, and continue into the chronic epileptic period

Energy levels of light atoms in strong magnetic fields

In this review article we provide an overview of the field of atomic structure of light atoms in strong magnetic fields. There is a very rich history of this field which dates back to the very birth of quantum mechanics. At various points in the past significant discoveries in science and technology have repeatedly served to rejuvenate interest in atomic structure in strong fields, broadly speaking, resulting in three eras in the development of this field; the historical, the classical and the modern eras. The motivations for studying atomic structure have also changed significantly as time progressed. The review presents a chronological summary of the major advances that occurred during these eras and discusses new insights and impetus gained. The review is concluded with a description of the latest findings and the future prospects for one of the most remarkably cutting-edge fields of research in science today.Comment: 37 pages, 16 figures, 1 tabl

Probing Single-Electron Spin Decoherence in Quantum Dots using Charged Excitons

We propose to use optical detection of magnetic resonance (ODMR) to measure the decoherence time T_{2} of a single electron spin in a semiconductor quantum dot. The electron is in one of the spin 1/2 states and a circularly polarized laser can only create an optical excitation for one of the electron spin states due to Pauli blocking. An applied electron spin resonance (ESR) field leads to Rabi spin flips and thus to a modulation of the photoluminescence or, alternatively, of the photocurrent. This allows one to measure the ESR linewidth and the coherent Rabi oscillations, from which the electron spin decoherence can be determined. We study different possible schemes for such an ODMR setup, including cw or pulsed laser excitation.Comment: 8 pages, 7 figures. Proceedings of the PASPS3 conference, Santa Barbara, CA (USA). To appear in the Journal of Superconductivit

Gut microbiota composition is associated with environmental landscape in honey bees.

There is growing recognition that the gut microbial community regulates a wide variety of important functions in its animal hosts, including host health. However, the complex interactions between gut microbes and environment are still unclear. Honey bees are ecologically and economically important pollinators that host a core gut microbial community that is thought to be constant across populations. Here, we examined whether the composition of the gut microbial community of honey bees is affected by the environmental landscape the bees are exposed to. We placed honey bee colonies reared under identical conditions in two main landscape types for 6 weeks: either oilseed rape farmland or agricultural farmland distant to fields of flowering oilseed rape. The gut bacterial communities of adult bees from the colonies were then characterized and compared based on amplicon sequencing of the 16S rRNA gene. While previous studies have delineated a characteristic core set of bacteria inhabiting the honey bee gut, our results suggest that the broad environment that bees are exposed to has some influence on the relative abundance of some members of that microbial community. This includes known dominant taxa thought to have functions in nutrition and health. Our results provide evidence for an influence of landscape exposure on honey bee microbial community and highlight the potential effect of exposure to different environmental parameters, such as forage type and neonicotinoid pesticides, on key honey bee gut bacteria. This work emphasizes the complexity of the relationship between the host, its gut bacteria, and the environment and identifies target microbial taxa for functional analyses

Positive effects of audit and feedback on antimicrobial use in hospitalized patients limited to audited patients

Objective: Audit and feedback is an antimicrobial stewardship (AMS) strategy, with the potential to also optimize antimicrobial use in non-audited patients. This study aimed to determine whether audit and feedback reduce antimicrobial use in both audited and non-audited patients.Design: Before-after trial with a 1-year intervention period and 2.5-year historical cohort.Setting: 750-bed community hospital in the Netherlands.Patients: All patients admitted to the urology wards during the 3.5-year study period were observed. Patients were classified as using antimicrobials if any antimicrobial was used for therapeutic reasons. Patients using antimicrobials prophylactically were excluded from measurements.Intervention: The AMS team provided audit and feedback on antimicrobial use for patients using antimicrobials for 2 days. Retrospectively, antimicrobial use and length of stay (LOS) were compared with the historical cohort.Results: Audits modified antimicrobial treatment in 52.8% of the cases. De-escalating, stopping, and switching from intravenous to oral treatment accounted for 72% of these modifications. Compared to patients from the cohort, who also used antimicrobials for 2 days, antimicrobial use decreased from 14.21 DDD/patient (95% CI, 13.08–15.34) to 11.45 DDD/patient (95% CI, 8.26–14.64; P = .047) for audited patients. Furthermore, mean LOS decreased from 7.42 days (95% CI, 6.79–8.06) to 6.13 days (95% CI, 5.38–6.89; P = .031). However, looking at all patients admitted to the urology wards, the percentage of patients using antimicrobials and total antimicrobial use remained unchanged.Conclusions: Audit and feedback reduce antimicrobial use and LOS, but only for audited patients. Positive effects are not automatically transferred to patients for whom no audits have been performed

Time-of-flight electron spectrometer for a broad range of kinetic energies

A newly constructed time-of-flight electron spectrometer of the magnetic bottle type is characterized for electron detection in a broad range of kinetic energies. The instrument is designed to measure the energy spectra of electrons generated from liquids excited by strong laser fields and photons in the range of extreme ultra violet and soft X-rays. Argon inner shell electrons were recorded to calibrate the spectrometer and investigate its characteristics, such as energy resolution and collection efficiency. Its energy resolution ΔE/E of 1.6% allows resolving the Ar 2p spin orbit structure at kinetic energies higher than 100 eV. The collection efficiency is determined and compared to that of the spectrometer in its field-free configuration