379 research outputs found

    Study program for encapsulation materials interface for low-cost solar array

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    The service integrity of the bonded interface in solar cell modules used in solar arrays is addressed. The development of AC impedance as a nondestructive evaluation (NDE) methodology for solar arrays is reported along with development of corrosion models and materials selection criteria for corrosion resistant interfaces

    The role of serotonin 1B in the representation of outcomes.

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    Disrupted serotonin neurotransmission has been implicated in the etiology of psychopathic traits. Empirical research has found that people with high levels of psychopathic traits have a deficit in reinforcement learning that is thought to be linked with amygdala dysfunction. Altered serotonin neurotransmission provides a plausible explanation for amygdala dysfunction in psychopathic traits and recent research suggests that this may be associated with serotonin 1B (5-HT1B) receptor function. This research used an animal model to test the hypothesis that 5-HT1B receptors are involved in the encoding of the specific features of reinforcing outcomes. An outcome devaluation task was used to test the effect of the systemic administration of a selective 5-HT1B receptor agonist administered before encoding of "action-outcome" associations. Results showed that while administration of a 5-HT1B receptor agonist allowed rats to acquire instrumental responding for food, when the content of that learning was further probed using an outcome devaluation task, performance differed from controls. 5-HT1B agonism impaired learning about the specific sensory qualities of food rewards associated with distinct instrumental responses, required to direct choice performance when the value of one outcome changed. These findings suggest a role for 5-HT1B receptor function in the encoding of the specific features of reinforcing outcomes

    Causes of cervical lymphadenopathy at Kamuzu Central Hospital

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    AimDescription of pathologic causes of cervical lymphadenopathy at Kamuzu Central Hospital.IntroductionThe evaluation of cervical lymphadenopathy is a common diagnostic challenge facing clinicians. Previously at Kamuzu Central Hospital (KCH) tuberculosis (TB) was reported to be the most common cause of cervical lymphadenopathy However, no recent study has assessed this common diagnostic challenge in Malawi, particularly since the beginning of the HIV epidemic and the subsequent scale-up of antiretroviral therapy.MethodsWe conducted a cross-sectional study of all cervical lymph node specimens from the KCH pathology laboratory between 1 July 2011 and 28 February 2013 and describe patient age, gender, and pathologic diagnoses.ResultsOur search of the KCH pathology database yielded 179 cases. Of these, 143 (77%) were histologic specimens (open biopsy or core needle samples) while 34 (23%) were cytology specimens. The age range was from 0 to 76 years with a mean of 30 (SD: 19). In adults, the most common diagnosis was malignancy (n=41, 35%), while in children 15 cases each of malignancy and benign masses were diagnosed. Only 6 cases (5%) of TB were diagnosed in adults, and 4 cases (6%) of TB were diagnosed in children.ConclusionOur study shows more malignancy and much less TB than a prior study of cervical lymphadenopathy at KCH. With the successful initiaion of the KCH Pathology Laboratory in 2011, we recommend biopsy or FNA early in the workup of cervical lymphadenopathy to prevent long delays in diagnosis and treatment of curable cancers

    Grounding knowledge and normative valuation in agent-based action and scientific commitment

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    Philosophical investigation in synthetic biology has focused on the knowledge-seeking questions pursued, the kind of engineering techniques used, and on the ethical impact of the products produced. However, little work has been done to investigate the processes by which these epistemological, metaphysical, and ethical forms of inquiry arise in the course of synthetic biology research. An attempt at this work relying on a particular area of synthetic biology will be the aim of this chapter. I focus on the reengineering of metabolic pathways through the manipulation and construction of small DNA-based devices and systems synthetic biology. Rather than focusing on the engineered products or ethical principles that result, I will investigate the processes by which these arise. As such, the attention will be directed to the activities of practitioners, their manipulation of tools, and the use they make of techniques to construct new metabolic devices. Using a science-in-practice approach, I investigate problems at the intersection of science, philosophy of science, and sociology of science. I consider how practitioners within this area of synthetic biology reconfigure biological understanding and ethical categories through active modelling and manipulation of known functional parts, biological pathways for use in the design of microbial machines to solve problems in medicine, technology, and the environment. We might describe this kind of problem-solving as relying on what Helen Longino referred to as “social cognition” or the type of scientific work done within what Hasok Chang calls “systems of practice”. My aim in this chapter will be to investigate the relationship that holds between systems of practice within metabolic engineering research and social cognition. I will attempt to show how knowledge and normative valuation are generated from this particular network of practitioners. In doing so, I suggest that the social nature of scientific inquiry is ineliminable to both knowledge acquisition and ethical evaluations

    Integrability and level crossing manifolds in a quantum Hamiltonian system

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    We consider a two-spin model, represented classically by a nonlinear autonomous Hamiltonian system with two degrees of freedom and a nontrivial integrability condition, and quantum mechanically by a real symmetric Hamiltonian matrix with blocks of dimensionalities K=l(l+1)/2, l=1,2,... In the six-dimensional (6D) parameter space of this model, classical integrability is satisfied on a 5D hypersurface, and level crossings occur on 4D manifolds that are completely embedded in the integrability hypersurface except for some lower-D sub-manifolds. Under mild assumptions, the classical integrability condition can be reconstructed from a purely quantum mechanical study of level degeneracies in finite-dimensional invariant blocks of the Hamiltonian matrix. Our conclusions are based on rigorous results for K=3 and on numerical results for K=6,10.Comment: 8 pages, 3 figure

    In-Clinic versus Hybrid Cancer Rehabilitation Service Delivery during the COVID-19 Pandemic: An Outcome Comparison Study

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    Diminished health-related quality of life (HRQOL) is common among cancer survivors but often amendable to rehabilitation. However, few access real-world rehabilitation services. Hybrid delivery modes (using a combination of in-clinic and synchronous telehealth visits) became popular during the COVID-19 pandemic and offer a promising solution to improve access beyond the pandemic. However, it is unclear if hybrid delivery has the same impact on patient-reported outcomes and experiences as standard, in-clinic-only delivery. To fill this gap, we performed a retrospective, observational, comparative outcomes study of real-world electronic medical record (EMR) data collected by a national outpatient rehabilitation provider in 2020–2021. Of the cases meeting the inclusion criteria (N = 2611), 60 were seen to via hybrid delivery. The outcomes evaluated pre and post-rehabilitation included PROMIS® global physical health (GPH), global mental health (GMH), physical function (PF), and the ability to participate in social roles and activities (SRA). The patient experience outcomes included the Net Promoter Survey (NPS®) and the Select Medical Patient-Reported Experience Measure (SM-PREM). A linear and logistic regression was used to examine the between-group differences in the PROMIS and SM-PREM scores while controlling for covariates. The hybrid and in-clinic-only cases improved similarly in all PROMIS outcomes (all p 0.05). No between-group differences were observed in the NPS or SM-PREM scores (all p > 0.05). Although more research is needed, this real-world evidence suggests that hybrid rehabilitation care may be equally beneficial for and acceptable to cancer survivors and supports calls to expand access to and reimbursement for telerehabilitation

    The effect of incentive spirometry on postoperative pulmonary function following laparotomy a randomized clinical trial

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    Importance: Changes in pulmonary dynamics following laparotomy are well documented. Deep breathing exercises, with or without incentive spirometry, may help counteract postoperative decreased vital capacity; however, the evidence for the role of incentive spirometry in the prevention of postoperative atelectasis is inconclusive. Furthermore, data are scarce regarding the prevention of postoperative atelectasis in sub-Saharan Africa. Objective: To determine the effect of the use of incentive spirometry on pulmonary function following exploratory laparotomy as measured by forced vital capacity (FVC). Design, Setting, and Participants: Thiswas a single-center, randomized clinical trial performed at Kamuzu Central Hospital, Lilongwe, Malawi. Study participants were adult patients who underwent exploratory laparotomy and were randomized into the intervention or control groups (standard of care) from February 1 to November 30, 2013. All patients received routine postoperative care, including instructions for deep breathing and early ambulation.We used bivariate analysis to compare outcomes between the intervention and control groups. Intervention: Adult patients who underwent exploratory laparotomy participated in postoperative deep breathing exercises. Patients in the intervention group received incentive spirometers Main outcomes and measures: We assessed pulmonary function using a peak flow meter to measure FVC in both groups of patients. Secondary outcomes, such as hospital length of stay and mortality, were obtained from the medical records. Results: A total of 150 patients were randomized (75 in each arm). The median age in the intervention and control groups was 35 years (interquartile range, 28-53 years) and 33 years (interquartile range, 23-46 years), respectively. Men predominated in both groups, and most patients underwent emergency procedures (78.7%in the intervention group and 84.0%in the control group). Mean initial FVC did not differ significantly between the intervention and control groups (0.92 and 0.90 L, respectively; P = .82 [95%CI, 0.52-2.29]). Although patients in the intervention group tended to have higher final FVC measurements, the change between the first and last measured FVC was not statistically significant (0.29 and 0.25 L, respectively; P = .68 [95%CI, 0.65-1.95]). Likewise, hospital length of stay did not differ significantly between groups. Overall postoperative mortality was 6.0%, with a higher mortality rate in the control group compared with the intervention group (10.7%and 1.3%, respectively; P = .02 [95%CI, 0.01-0.92]). Conclusions and Relevance: Education and provision of incentive spirometry for unmonitored patient use does not result in statistically significant improvement in pulmonary dynamics following laparotomy.We would not recommend the addition of incentive spirometry to the current standard of care in this resource-constrained environment. Trial registration: clinicaltrials.gov Identifier: NCT01789177

    Mephedrone in adolescent rats: residual memory impairment and acute but not lasting 5-HT depletion

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    Mephedrone (4-methylmethcathinone, MMC) is a popular recreational drug, yet its potential harms are yet to be fully established. The current study examined the impact of single or repeated MMC exposure on various neurochemical and behavioral measures in rats. In Experiment 1 male adolescent Wistar rats received single or repeated (once a day for 10 days) injections of MMC (30 mg/kg) or the comparator drug methamphetamine (METH, 2.5 mg/kg). Both MMC and METH caused robust hyperactivity in the 1 h following injection although this effect did not tend to sensitize with repeated treatment. Striatal dopamine (DA) levels were increased 1 h following either METH or MMC while striatal and hippocampal serotonin (5-HT) levels were decreased 1 h following MMC but not METH. MMC caused greater increases in 5-HT metabolism and greater reductions in DA metabolism in rats that had been previously exposed to MMC. Autoradiographic analysis showed no signs of neuroinflammation ([125I]CLINDE ligand used as a marker for translocator protein (TSPO) expression) with repeated exposure to either MMC or METH. In Experiment 2, rats received repeated MMC (7.5, 15 or 30 mg/kg once a day for 10 days) and were examined for residual behavioral effects following treatment. Repeated high (30 mg/kg) dose MMC produced impaired novel object recognition 5 weeks after drug treatment. However, no residual changes in 5-HT or DA tissue levels were observed at 7 weeks post-treatment. Overall these results show that MMC causes acute but not lasting changes in DA and 5-HT tissue concentrations. MMC can also cause long-term memory impairment. Future studies of cognitive function in MMC users are clearly warranted. © 2012 PLoS On

    Causes of cervical lymphadenopathy at Kamuzu Central Hospital

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    Aim: Description of pathologic causes of cervical lymphadenopathy at Kamuzu Central Hospital. Introduction: The evaluation of cervical lymphadenopathy is a common diagnostic challenge facing clinicians. Previously at Kamuzu Central Hospital (KCH) tuberculosis (TB) was reported to be the most common cause of cervical lymphadenopathy However, no recent study has assessed this common diagnostic challenge in Malawi, particularly since the beginning of the HIV epidemic and the subsequent scale-up of antiretroviral therapy. Methods: We conducted a cross-sectional study of all cervical lymph node specimens from the KCH pathology laboratory between 1 July 2011 and 28 February 2013 and describe patient age, gender, and pathologic diagnoses. Results: Our search of the KCH pathology database yielded 179 cases. Of these, 143 (77%) were histologic specimens (open biopsy or core needle samples) while 34 (23%) were cytology specimens. The age range was from 0 to 76 years with a mean of 30 (SD: 19). In adults, the most common diagnosis was malignancy (n=41, 35%), while in children 15 cases each of malignancy and benign masses were diagnosed. Only 6 cases (5%) of TB were diagnosed in adults, and 4 cases (6%) of TB were diagnosed in children. Conclusion: Our study shows more malignancy and much less TB than a prior study of cervical lymphadenopathy at KCH. With the successful initiaion of the KCH Pathology Laboratory in 2011, we recommend biopsy or FNA early in the workup of cervical lymphadenopathy to prevent long delays in diagnosis and treatment of curable cancers

    Policy design for an ageing population

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    Published online: 29 Mar 2018.This article describes how a state government in Australia designed and implemented policy for an ageing population. In 1984, the parliament of South Australia passed legislation which aimed to lay a foundation for the successful ageing of the population. Three components are examined here, the legislation, policy design, and practice. Although the legislation was passed more than 30 years ago, there are lessons and implications for today. The author was appointed Commissioner in 1985 and had responsibility for the policy design and implementation.Adam Grayca
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