On processing development for fabrication of fiber reinforced composite, part 2

Fiber-reinforced composite laminates are used in many aerospace and automobile applications. The magnitudes and durations of the cure temperature and the cure pressure applied during the curing process have significant consequences for the performance of the finished product. The objective of this study is to exploit the potential of applying the optimization technique to the cure cycle design. Using the compression molding of a filled polyester sheet molding compound (SMC) as an example, a unified Computer Aided Design (CAD) methodology, consisting of three uncoupled modules, (i.e., optimization, analysis and sensitivity calculations), is developed to systematically generate optimal cure cycle designs. Various optimization formulations for the cure cycle design are investigated. The uniformities in the distributions of the temperature and the degree with those resulting from conventional isothermal processing conditions with pre-warmed platens. Recommendations with regards to further research in the computerization of the cure cycle design are also addressed

Organizational stressors, coping, and coping effectiveness in collegiate squash players.

Coping is defined as “constantly changing cognitive and behavioural efforts to manage specific external and/or internal demands that are appraised as taxing or exceeding the resources of the person” (Lazarus & Folkman, 1984, p. 141). It has been suggested that research is needed to explore and evaluate the effectiveness of the coping strategies that athletes use to deal with the organizational stressors they encounter (Fletcher, Hanton, & Mellalieu, 2006). Therefore, this study explored the relationships between the organizational stressors encountered and the coping strategies employed to manage them. Furthermore, the effectiveness of these strategies was examined. Data were collected from eight Caucasian male squash players (Mage 20.88, SD = 1.46 years) using daily diaries over a 28-day period of training and competition. The results reveal that participants encountered a wide range of organizational stressors, the most common being “factors intrinsic to the sport” and “sport relationships and interpersonal demands”. The most common coping strategy employed to manage these demands was problem-focused coping, few strategies were used to cope with more than one stressor, and the effectiveness of the coping strategies used varied for each dimension of stressors. By investigating the relationships between organizational stressors and coping, and examining the effectiveness of these strategies, this study furthers our understanding of coping in sport performers and highlights the important role of effective coping in the organizational stress process. Furthermore, the results suggest that the most effective coping strategies were stressor-specific, which has important implications for applied practitioners. In order to implement effective psychological skills training and encourage athletes to manage the array of organizational stressors that they encounter, the stressor-coping relationships should be considered to allow practitioners to educate athletes on the most effective ways to deal with different stressors

Mechanisms of cognitive-behavioral therapy for obsessive-compulsive disorder involve robust and extensive increases in brain network connectivity.

Cognitive-behavioral therapy (CBT) is effective for obsessive compulsive disorder (OCD); however, little is understood about its mechanisms related to brain network connectivity. We examined connectivity changes from resting-state functional magnetic resonance imaging data pre-to-post-CBT in 43 OCD participants, randomized to receive either 4 weeks of intensive CBT or 4 weeks waitlist followed by 4 weeks of CBT, and 24 healthy controls before and after 4 weeks of no treatment. Network-based-statistic analysis revealed large-magnitude increases in OCD connectivity in eight networks. Strongest increases involved connectivity between the cerebellum and caudate/putamen, and between the cerebellum and dorsolateral/ventrolateral prefrontal cortices. Connectivity increases were associated with increased resistance to compulsions. Mechanisms of CBT may involve enhanced cross-network integration, both within and outside of classical cortico-striatal-thalamo-cortical regions; those involving cerebellar to striatal and prefrontal regions may reflect acquisition of new non-compulsive goal-directed behaviors and thought patterns. Our findings have implications for identifying targets for enhancing treatment efficacy and monitoring treatment progress

Paramedics’ Confidence and Perceived Competence When Attending to Varied Patient Presentations: A Mixed-Method Study

Purpose: Paramedics are routinely called to patients presenting with mental health concerns. Previous literature suggests paramedics find this patient group challenging. However, no study has investigated whether paramedics find mental health presentations (MHP) more challenging relative to other patient presentations, or whether certain paramedic variables relate to their perceived ability to manage MHP. This study investigates differences in paramedics’ perceived ability to attend to MHP compared to other patient presentations, and whether their perceived ability is related to their level of experience or location of work (metropolitan or rural). The study also explores paramedic’s experiences and perspectives of MHP. Method: Operational paramedics in Australia (n = 138) completed a survey assessing their perceived ability to respond to mental health, cardiac, respiratory, and trauma-related presentations. A repeated measures ANOVA tested differences in perceived ability between these patient presentations. T-tests and Pearson’s correlations were conducted to determine whether years of experience or location of work related to their perceived ability for MHP. Nine paramedics were also interviewed, and a thematic analysis conducted to gain insight into paramedic’s experiences and perspectives of MHP. Results: Paramedics reported a significantly lower perceived ability to respond to MHP relative to each other patient presentation measured. No relationships were found between a paramedic’s perceived ability to respond to MHP and their length of work experience or location of work. Interviews with paramedics revealed four superordinate themes: 1) inconsistent conceptualization of their role, 2) feelings of helplessness and frustration, 3) stigmatized views of patients with a mental illness, and 4) inconsistent views of knowledge and learning relating to MHP. Conclusions: Paramedics believe they have a significantly poorer ability to respond to MHP relative to other patient presentations. Education and training focused on defining a paramedic’s role for MHP as well as reducing stigmatized views of patients with a mental illness may improve paramedic’s care of this cohort of patients

Detecting Mutations in the Mycobacterium tuberculosis Pyrazinamidase Gene pncA to Improve Infection Control and Decrease Drug Resistance Rates in Human Immunodeficiency Virus Coinfection.

Hospital infection control measures are crucial to tuberculosis (TB) control strategies within settings caring for human immunodeficiency virus (HIV)-positive patients, as these patients are at heightened risk of developing TB. Pyrazinamide (PZA) is a potent drug that effectively sterilizes persistent Mycobacterium tuberculosis bacilli. However, PZA resistance associated with mutations in the nicotinamidase/pyrazinamidase coding gene, pncA, is increasing. A total of 794 patient isolates obtained from four sites in Lima, Peru, underwent spoligotyping and drug resistance testing. In one of these sites, the HIV unit of Hospital Dos de Mayo (HDM), an isolation ward for HIV/TB coinfected patients opened during the study as an infection control intervention: circulating genotypes and drug resistance pre- and postintervention were compared. All other sites cared for HIV-negative outpatients: genotypes and drug resistance rates from these sites were compared with those from HDM. HDM patients showed high concordance between multidrug resistance, PZA resistance according to the Wayne method, the two most common genotypes (spoligotype international type [SIT] 42 of the Latino American-Mediterranean (LAM)-9 clade and SIT 53 of the T1 clade), and the two most common pncA mutations (G145A and A403C). These associations were absent among community isolates. The infection control intervention was associated with 58-92% reductions in TB caused by SIT 42 or SIT 53 genotypes (odds ratio [OR] = 0.420, P = 0.003); multidrug-resistant TB (OR = 0.349, P < 0.001); and PZA-resistant TB (OR = 0.076, P < 0.001). In conclusion, pncA mutation typing, with resistance testing and spoligotyping, was useful in identifying a nosocomial TB outbreak and demonstrating its resolution after implementation of infection control measures

A programme for the prevention of post-traumatic stress disorder in midwifery (POPPY): indications of effectiveness from a feasibility study

Background: Midwives can experience events they perceive as traumatic when providingcare. As a result, some will develop post-traumatic stress disorder (PTSD), with adverse implications for their mental health, the quality of care provided for women and the employing organizations. POPPY (Programme for the prevention of PTSD in midwifery) is a package of educational and supportive resources comprising an educational workshop, information leaflet, peer support and access to trauma-focused clinical psychology intervention. A feasibility study of POPPY implementation was completed. Objective: This study aimed to identify potential impacts of POPPY on midwives’ understandingof trauma, their psychological well-being and job satisfaction. Method: POPPY was implemented in one hospital site. Before taking part in the POPPY workshop (T1) midwives (N = 153) completed self-report questionnaires, which measured exposure to work-related trauma, knowledge and confidence of managing trauma responses, professional impacts, symptoms of PTSD, burnout and job satisfaction. Measures were repeated (T2) approximately 6 months after training (n = 91, 62%). Results: Midwives’ confidence in recognizing (p = .001) and managing early traumaresponses in themselves and their colleagues significantly improved (both p < .001). There was a trend towards reduced levels of PTSD symptomatology, and fewer midwives reported sub clinical levels of PTSD (from 10% at T1 to 7% at T2). The proportion of midwives reporting high and moderate levels of depersonalization towards care was reduced (33% to 20%) and midwives reported significantly higher levels of job satisfaction at T2 (p < .001). Reductions in self-reported stress-related absenteeism (12% to 5%), long-term changes to clinical allocation (10% to 5%) and considerations about leaving midwifery (34% to 27%) were identified. Conclusions: In conclusion, POPPY shows very positive potential to improve midwives’ mental health and the sensitivity of care they provide, and reduce service disruption and costs for trusts. Large-scale longitudinal evaluation is required

Metallochaperones Are Needed for Mycobacterium tuberculosis and Escherichia coli Nicotinamidase-Pyrazinamidase Activity.

Mycobacterium tuberculosis nicotinamidase-pyrazinamidase (PZAse) is a metalloenzyme that catalyzes conversion of nicotinamide-pyrazinamide to nicotinic acid-pyrazinoic acid. This study investigated whether a metallochaperone is required for optimal PZAse activity. M. tuberculosis and Escherichia coli PZAses (PZAse-MT and PZAse-EC, respectively) were inactivated by metal depletion (giving PZAse-MT-Apo and PZAse-EC-Apo). Reactivation with the E. coli metallochaperone ZnuA or Rv2059 (the M. tuberculosis analog) was measured. This was repeated following proteolytic and thermal treatment of ZnuA and Rv2059. The CDC1551 M. tuberculosis reference strain had the Rv2059 coding gene knocked out, and PZA susceptibility and the pyrazinoic acid (POA) efflux rate were measured. ZnuA (200 μM) achieved 65% PZAse-EC-Apo reactivation. Rv2059 (1 μM) and ZnuA (1 μM) achieved 69% and 34.3% PZAse-MT-Apo reactivation, respectively. Proteolytic treatment of ZnuA and Rv2059 and application of three (but not one) thermal shocks to ZnuA significantly reduced the capacity to reactivate PZAse-MT-Apo. An M. tuberculosis Rv2059 knockout strain was Wayne positive and susceptible to PZA and did not have a significantly different POA efflux rate than the reference strain, although a trend toward a lower efflux rate was observed after knockout. The metallochaperone Rv2059 restored the activity of metal-depleted PZAse in vitro Although Rv2059 is important in vitro, it seems to have a smaller effect on PZA susceptibility in vivo. It may be important to mechanisms of action and resistance to pyrazinamide in M. tuberculosis Further studies are needed for confirmation.IMPORTANCE Tuberculosis is an infectious disease caused by the bacterium Mycobacterium tuberculosis and remains one of the major causes of disease and death worldwide. Pyrazinamide is a key drug used in the treatment of tuberculosis, yet its mechanism of action is not fully understood, and testing strains of M. tuberculosis for pyrazinamide resistance is not easy with the tools that are presently available. The significance of the present research is that a metallochaperone-like protein may be crucial to pyrazinamide's mechanisms of action and of resistance. This may support the development of improved tools to detect pyrazinamide resistance, which would have significant implications for the clinical management of patients with tuberculosis: drug regimens that are appropriately tailored to the resistance profile of a patient's individual strain lead to better clinical outcomes, reduced onward transmission of infection, and reduction of the development of resistant strains that are more challenging and expensive to treat

F. John's stability conditions vs. A. Carasso's SECB constraint for backward parabolic problems

In order to solve backward parabolic problems F. John [{\it Comm. Pure. Appl. Math.} (1960)] introduced the two constraints "$\|u(T)\|\le M$" and $\|u(0) - g \| \le \delta$ where $u(t)$ satisfies the backward heat equation for $t\in(0,T)$ with the initial data $u(0).$ The {\it slow-evolution-from-the-continuation-boundary} (SECB) constraint has been introduced by A. Carasso in [{\it SIAM J. Numer. Anal.} (1994)] to attain continuous dependence on data for backward parabolic problems even at the continuation boundary $t=T$. The additional "SECB constraint" guarantees a significant improvement in stability up to $t=T.$ In this paper we prove that the same type of stability can be obtained by using only two constraints among the three. More precisely, we show that the a priori boundedness condition $\|u(T)\|\le M$ is redundant. This implies that the Carasso's SECB condition can be used to replace the a priori boundedness condition of F. John with an improved stability estimate. Also a new class of regularized solutions is introduced for backward parabolic problems with an SECB constraint. The new regularized solutions are optimally stable and we also provide a constructive scheme to compute. Finally numerical examples are provided.Comment: 15 pages. To appear in Inverse Problem