825 research outputs found
NASA contributions to fluidic systems: A survey
A state-of-the art review of fluidic technology is presented. It is oriented towards systems applications rather than theory or design. It draws heavily upon work performed or sponsored by NASA in support of the space program and aeronautical research and development (R&D). Applications are emphasized in this survey because it is hoped that the examples described and the criteria presented for evaluating the suitability of fluidics to new applications will be of value to potential users of fluidic systems. This survey of the fluidics industry suggests some of the means whereby a company may use a fluidic system effectively either to manufacture a product or as part of the end product
Effects of horizontal vibration on hopper flows of granular materials
The current experiments investigate the discharge of glass spheres in a planar wedge-shaped hopper (45 degree sidewalls) that is vibrated hoizontally. When the hopper is discharged without vibration, the discharge occurs as a funnel flow, with the material exiting the central region of the hopper and stagnant material along the sides. With horizontal vibration, the discharge rate increases with the velocity of vibration as compared with the discharge rate without vibration. For a certain range of acceleration parameters (20-30 Hz and accelerations greater than about 1 g), the discharge of the material occurs in an inverted-funnel pattern, with the material along the sides exiting first, followed by the material in the core; the free surface shows a peak at the center of the hopper with the free surface particles avalanching from the center toward the sides. During the deceleration phase of a vibration cycle, particles all along the trailing or low-pressure wall separate from the surface and fall under gravity for a short period before reconnecting the hopper. For lower frequencies (5 and 10 Hz), the free surface remains horizontal and the material appears to discharge uniformly from the hopper
Effects of Horizontal Vibration on Hopper Flows of Granular Material
This study experimentally examines the flow of glass spheres in a wedge-shaped hopper that is vibrated hoizontally. When the hopper is discharged without vibration, discharge occurs as a funnel flow, with the material exiting the central region of the hopper and stagnant material along the sides. With vibration, the discharge of the material occurs in reverse, with the material along the sides exiting first, followed by the material in the central region. These patterns are observed with flow visualization and high-speed photography. The study also includes measurements of the discharge rate, which increases with the amplitude of the velocity of vibration
Use of whole plant Artemisia annua L. as an antimalarial therapy
Anti-malarial drugs are primary weapons for reducing Plasmodium transmission in human populations. Successful drugs have been highly efficacious and inexpensive to synthetically manufacture. Emergence of resistant parasites reduces the lifespan of each drug that is developed and deployed. Currently, the most effective anti-malarial is artemisinin (AN), which is extracted from the leaves of Artemisia annua. Because of its poor pharmacokinetic properties and prudent efforts to curtail emergence of resistance, AN is prescribed only in combination with other anti-malarials composing an Artemisinin Combination Therapy (ACT). Low yield in the plant and the added cost of secondary anti-malarials in the ACT, make AN in the developing world a costly treatment. Here we show that dried leaves of A. annua administered orally are more effective at killing malaria parasites than a comparable dose of purified drug in a rodent malaria model (P. chabaudi). A single dose of whole plant (WP) A. annua containing 24 mg/kg AN clears 99% of parasites, where a comparable dose of pure drug has half that effect. This is consistent with findings that blood levels of AN are 40 times greater in mice receiving WP versus those given pure drug. We hypothesize that in addition to increasing bioavailability of AN, administration of WP alone may constitute a combination therapy because it contains other anti-malarial compounds that have been shown to synergize with AN. Inexpensive, efficacious, and resilient treatment for malaria based upon WP A. annua that can be grown and processed locally would be an effective addition to the global effort to reduce malaria morbidity and mortality
Integrating Science and Policy: A Case Study of the Hubbard Brook Research Foundation Science Links Program
Scientists, related professionals, and the public have for decades called for greater interaction among scientists, policymakers, and the media to address contemporary environmental challenges. Practical examples of effective “real-world” programs designed to catalyze interactions and provide relevant science are few. Existing successful models can be used, however, to develop and expand the work of integrating, synthesizing, and communicating ecosystem science for environmental policy and natural-resource management. We provide an overview of the structure and strategies used in the Hubbard Brook Research Foundation Science Links program, now in its thirteenth year as a successful boundary-spanning organization. We detail project activities and results and share lessons and challenges for the further advancement of Science Links and other efforts to bridge the science–policy divide. Furthermore, we suggest greater emphasis in boundary-spanning programs as a part of publicly funded research initiatives and as legitimate scholarly endeavors that support the scaled coproduction of knowledge and that harness scientific research to support informed policy and environmental management
Developing a Whole Plant Artemisia annua Antimalarial Therapeutic: pACT
The GRAS plant Artemisia annua L. produces the sesquiterpene lactone, artemisinin. The current therapy for malaria is artemisinin + an older drug: artemisinin combination therapy (ACT). In Plasmodium chabaudi-infected mice, dried leaves of A. annua are more potent than equal amounts of pure artemisinin and may also prevent artemisinin drug resistance from emerging. This whole plant therapy is pACT: plant-based artemisinin combination therapy. Pharmacokinetics in healthy and infected mice given either pure artemisinin or pACT is different and showed that \u3e 40 fold more artemisinin enters the blood when plant material is present; plant matrix enhanced bioavailability into serum. Dried leaves as capsules or tablets given to African malaria patients were also efficacious. Flavonoids, phenolic acids, monoterpenes and other artemisinic metabolites found in the plant have mild antimalarial activity. Some may synergize with artemisinin to enhance its efficacy. In simulated digestion studies the effects of cellulose and gelatin capsules, sucrose, 4 oils, and 3 staple grains (rice, corn, and millet) were studied to determine their effect on AN and flavonoid release into the liquid phase of the intestinal stage of digestion. Compared to pACT alone: sucrose and oil enhanced release of flavonoids by 100%, but artemisinin was unaffected; both capsule types, and corn and millet meal significantly reduced artemisinin release, but had no effect on flavonoids. From field trials in MA, it was estimated that \u3e 500,000 patients could be treated from plants grown on 1 ac of land. Analysis of 10 crops of the high artemisinin-producing WPI clone of A. annua grown under different field and lab conditions showed there was consistent production of artemisinin at about 1.4% DW. Together these results show how a simple herbal remedy could be used as an efficacious, inexpensive, controlled and sustainable orally delivered therapeutic for treating malaria and other artemisinin-susceptible diseases
Evaluating patterns of fog water deposition and isotopic composition on the California Channel Islands
The Role of Disgust in Posttraumatic Stress: A Critical Review of the Empirical Literature
The current review provides a detailed analysis of the burgeoning literature examining the role of disgust in understanding posttraumatic stress symptomatology. Research in this area generally converges to suggest (1) posttraumatic stress is associated with the experience of elevated disgust, (2) individual differences in disgust vulnerabilities may relate to increased posttraumatic stress symptom levels, (3) retrospective report of peritraumatic disgust is related to posttraumatic stress symptom levels, and (4) posttraumatic stress symptom levels appear to be associated with increased disgust, including in response to traumatic event cues. Importantly, much of this research suggests observed relations between disgust and posttraumatic stress are at least somewhat unique from relations between fear/anxiety and posttraumatic stress. Future research is now needed to identify mechanisms involved in these relations in order to inform the prevention and treatment of disgust-related posttraumatic stress disorder
Post-traumatic stress disorder following patient assaults among staff members of mental health hospitals: a prospective longitudinal study
BACKGROUND: Violence by patients against staff members in mental health institutions has become an important challenge. Violent attacks may not only cause bodily injuries but can also have posttraumatic consequences with high rates of stress for mental health staff. This study prospectively assessed posttraumatic stress disorder (PTSD) in employees who were severely assaulted by patients in nine German state mental health institutions. METHODS: During the study period of six months 46 assaulted staff members were reported. Each staff member was interviewed three times after the violent incident, using the Impact of Event Scale-Revised (IES-R), a widely used PTSD research tool, as well as the Posttraumatic Stress Disorder Checklist – Civilian (PCL-C). RESULTS: In the baseline assessment following an assault by a patient, eight subjects (17%) met the criteria for PTSD. After two and six months, three and four subjects respectively still met diagnosis criteria. CONCLUSION: A small minority of assaulted employees suffer from PTSD for several months after a patient assault
Interpretative Phenomenological Analysis of Soldiers’ Experiences of Being Married and Serving in the British Army
© 2016, Copyright © Taylor & Francis Group, LLC. ABSTRACT: Research suggests certain aspects of military life, especially operational deployments, may negatively impact military marriages. However, much of this research is from the United States and uses deductive quantitative methods. Qualitative research investigating the lived experiences of forming and maintaining marriages was conducted with six male U.K. Army personnel. Semistructured interviews were analyzed, using Interpretative Phenomenological Analysis, identifying five themes, each representing different dilemmas the soldiers’ had to balance to maintain successful marriages and Army careers. These five themes are best understood as practical, emotional, and cultural dilemmas that can be alleviated with practical and emotional methods; such factors could be used to build resilience in soldier’s marriages. These possible resilience factors could shape the content of interventions to increase resiliency in military marriages
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