Effect of processing parameters on reaction bonding of silicon nitride

Reaction bonded silicon nitride was developed. The relationship between the various processing parameters and the resulting microstructures was to design and synthesize reaction bonded materials with improved room temperature mechanical properties

Prescription for antidepressant in reducing future alcohol-related readmission in patients suffering from depression and alcohol use disorder: a retrospective medical record review

BACKGROUND: Patients suffering from major depressive disorder are more likely to suffer from alcohol use disorder. The data is inconclusive for the effectiveness of antidepressant treatment of patients suffering from both illnesses in regards to improving sobriety and reducing alcohol-related healthcare expenses such as hospitalizations. The objective of this study is to determine if a new prescription of an antidepressant upon inpatient discharge is associated with a reduction in the number of future acute alcohol-related hospital readmissions to the same institution in patients suffering from major depressive disorder and alcohol-use disorder. METHODS: A retrospective, medical record review study was conducted at a publicly-supported hospital in Sylmar, CA. A query was performed for adult patients admitted between 1/1/2005-12/31/2013 who had ICD-9 codes for both alcohol-use disorder and depression. Index admission was the first hospitalization in which the patient was currently consuming alcohol and had depression as identified by physician documentation as a problem. Acute alcohol-related admissions were those for alcohol intoxication or withdrawal (indicating current alcohol use). Patients were excluded if they were receiving an antidepressant on index admission,old, no patient data available, or not currently consuming alcohol; 139 patients met inclusion criteria. Multivariate logistical regression analysis was performed on the primary predictive variable of discharge prescription of an antidepressant along with other independent variables for alcohol readmissions: homelessness, family history of alcohol use disorder, and smoking. RESULTS: Discharging patients with a prescription of an antidepressant was not associated with a reduction in acute alcohol-related readmission. There was no difference in acute alcohol-related readmissions between patients discharged with (44.6 %) versus without (47.0 %) a prescription for an antidepressant (p = 0.863). The median number of days between index admission and first readmission for those discharged on an antidepressant was 141 days while those who were not was 112 days (p = 0.284). CONCLUSION: Discharging patients suffering from both alcohol-use disorder and major depressive disorder with a prescription for an antidepressant is not associated with a reduction in future readmissions, nor significantly increase the number of days to readmission. The study does not support the concept of antidepressants in reducing acute alcohol-related readmissions

Expert Testimony on Proximate Cause

Expert testimony is common in tort litigation, especially on issues of standard of care and cause-in-fact. Rule 704 of the Federal Rules of Evidence and its state counterparts abolished the prohibition of testimony on ultimate issues, leading to the possibility of expert testimony on the often crucial issue of proximate cause. The situation is easy to imagine. After counsel has qualified an expert witness and elicited an opinion that the particular act or omission caused the injury in question, counsel might very well be tempted to inquire whether the witness has an opinion as to whether the act or omission was a proximate or legal cause of the accident. Or, counsel may merge the two lines of inquiry and ask whether the act or omission proximately resulted in the accident or injury to the plaintiff. The inquiry seems harmless. The term proximate is commonly understood to mean only near or close to. The question is not innocuous, however. The issue of expert testimony on the question of proximate cause implicates several restrictions on expert testimony that survive the broad permission of Rule 704, and touches upon the serious issue of the proper roles of expert and fact-finder in the application of law to facts. The few published cases that have considered the issue of expert testimony on proximate cause are split.\u27 The question arises far more often, however, than is indicated by the relative scarcity of reported decisions. This Article addresses the usefulness and propriety of expert testimony on the issue of proximate cause. After briefly defining the concept of proximate cause, this Article argues that expert testimony on proximate cause is inadmissible under Rule 704, despite the general admissibility of testimony on ultimate issues. In addition, opinion on proximate cause is inadmissible because it fails to clear the separate hurdles of Rules 702\u27 and 4036 of the Federal Rules of Evidence. A technical expert on standard of care or actual cause is not qualified to opine on the issue of proximate cause and thus fails the expertise test of Rule 702. Furthermore, even the testimony of a genuine expert on the issue of proximate cause should be excluded because such testimony fails the helpfulness test of Rule 702. Finally, expert testimony on the issue of proximate cause is inadmissible under Rule 403 because its probative value is substantially outweighed by the possibility that such testimony will confuse the issues and mislead the jury

Analysis of electroencephalograms in Alzheimer's disease patients with multiscale entropy

The aim of this study was to analyse the electroencephalogram (EEG) background activity of Alzheimer’s disease (AD) patients using the Multiscale Entropy (MSE). The MSE is a recently developed method that quantifies the regularity of a signal on different time scales. These time scales are inspected by means of several coarse-grained sequences formed from the analysed signals. We recorded the EEGs from 19 scalp electrodes in 11 AD patients and 11 age-matched controls and estimated the MSE profile for each epoch of the EEG recordings. The shape of the MSE profiles reveals the EEG complexity, and it suggests that the EEG contains information in deeper scales than the smallest one. Moreover, the results showed that the EEG background activity is less complex in AD patients than control subjects. We found significant difference

Granular Rheology in Zero Gravity

We present an experimental investigation on the rheological behavior of model granular media made of nearly elastic spherical particles. The experiments are performed in a cylindrical Couette geometry and the experimental device is placed inside an airplane undergoing parabolic flights to cancel the effect of gravity. The corresponding curves, shear stress versus shear rate, are presented and a comparison with existing theories is proposed. The quadratic dependence on the shear rate is clearly shown and the behavior as a function of the solid volume fraction of particles exhibits a power law function. It is shown that theoretical predictions overestimate the experiments. We observe, at intermediate volume fractions, the formation of rings of particles regularly spaced along the height of the cell. The differences observed between experimental results and theoretical predictions are discussed and related to the structures formed in the granular medium submitted to the external shear.Comment: 10 pages, 6 figures to be published in Journal of Physics : Condensed Matte

Scaling Behaviour and Complexity of the Portevin-Le Chatelier Effect

The plastic deformation of dilute alloys is often accompanied by plastic instabilities due to dynamic strain aging and dislocation interaction. The repeated breakaway of dislocations from and their recapture by solute atoms leads to stress serrations and localized strain in the strain controlled tensile tests, known as the Portevin-Le Chatelier (PLC) effect. In this present work, we analyse the stress time series data of the observed PLC effect in the constant strain rate tensile tests on Al-2.5%Mg alloy for a wide range of strain rates at room temperature. The scaling behaviour of the PLC effect was studied using two complementary scaling analysis methods: the finite variance scaling method and the diffusion entropy analysis. From these analyses we could establish that in the entire span of strain rates, PLC effect showed Levy walk property. Moreover, the multiscale entropy analysis is carried out on the stress time series data observed during the PLC effect to quantify the complexity of the distinct spatiotemporal dynamical regimes. It is shown that for the static type C band, the entropy is very low for all the scales compared to the hopping type B and the propagating type A bands. The results are interpreted considering the time and length scales relevant to the effect.Comment: 35 pages, 6 figure

Independent evaluation of a simple clinical prediction rule to identify right ventricular dysfunction in patients with shortness of breath

BACKGROUND: Many patients have unexplained persistent dyspnea after negative computed tomographic pulmonary angiography (CTPA). We hypothesized that many of these patients have isolated right ventricular (RV) dysfunction from treatable causes. We previously derived a clinical decision rule (CDR) for predicting RV dysfunction consisting of persistent dyspnea and normal CTPA, finding that 53% of CDR-positive patients had isolated RV dysfunction. Our goal is to validate this previously derived CDR by measuring the prevalence of RV dysfunction and outcomes in dyspneic emergency department patients. METHODS: A secondary analysis of a prospective observational multicenter study that enrolled patients presenting with suspected PE was performed. We included patients with persistent dyspnea, a nonsignificant CTPA, and formal echo performed. Right ventricular dysfunction was defined as RV hypokinesis and/or dilation with or without moderate to severe tricuspid regurgitation. RESULTS: A total of 7940 patients were enrolled. Two thousand six hundred sixteen patients were analyzed after excluding patients without persistent dyspnea and those with a significant finding on CTPA. One hundred ninety eight patients had echocardiography performed as standard care. Of those, 19% (95% confidence interval [CI], 14%-25%) and 33% (95% CI, 25%-42%) exhibited RV dysfunction and isolated RV dysfunction, respectively. Patients with isolated RV dysfunction or overload were more likely than those without RV dysfunction to have a return visit to the emergency department within 45 days for the same complaint (39% vs 18%; 95% CI of the difference, 4%-38%). CONCLUSION: This simple clinical prediction rule predicted a 33% prevalence of isolated RV dysfunction or overload. Patients with isolated RV dysfunction had higher recidivism rates and a trend toward worse outcomes

Point perturbations of circle billiards

The spectral statistics of the circular billiard with a point-scatterer is investigated. In the semiclassical limit, the spectrum is demonstrated to be composed of two uncorrelated level sequences. The first corresponds to states for which the scatterer is located in the classically forbidden region and its energy levels are not affected by the scatterer in the semiclassical limit while the second sequence contains the levels which are affected by the point-scatterer. The nearest neighbor spacing distribution which results from the superposition of these sequences is calculated analytically within some approximation and good agreement with the distribution that was computed numerically is found.Comment: 9 pages, 2 figure

An invitation to grieve: reconsidering critical incident responses by support teams in the school setting

This paper proposes that consideration could be given to an invitational intervention rather than an expectational intervention when support personnel respond to a critical incident in schools. Intuitively many practitioners know that it is necessary for guidance/counselling personnel to intervene in schools in and following times of trauma. Most educational authorities in Australia have mandated the formulation of a critical incident intervention plan. This paper defines the term critical incident and then outlines current intervention processes, discussing the efficacy of debriefing interventions. Recent literature suggests that even though it is accepted that a planned intervention is necessary, there is scant evidence as to the effectiveness of debriefing interventions in stemming later symptoms of post traumatic stress disorder. The authors of this paper advocate for an expressive therapy intervention that is invitational rather than expectational, arguing that not all people respond to trauma in the same way and to expect that they will need to recall and retell what has happened is most likely a dangerous assumption. A model of invitation using Howard Gardner’s (1983) multiple intelligences is proposed so that students are invited to grieve and understand emotionally what is happening to them following a critical incident