352 resultados para attrition
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Background: Until recently, little was known about the costs of the HIV/AIDS epidemic to businesses in Africa and business responses to the epidemic. This paper synthesizes the results of a set of studies conducted between 1999 and 2006 and draws conclusions about the role of the private sector in Africa’s response to AIDS. Methods: Detailed human resource, financial, and medical data were collected from 14 large private and parastatal companies in South Africa, Uganda, Kenya, Zambia, and Ethiopia. Surveys of small and medium-sized enterprises (SMEs) were conducted in South Africa, Kenya, and Zambia. Large companies’ responses or potential responses to the epidemic were investigated in South Africa, Uganda, Kenya, Zambia, and Rwanda. Results: Among the large companies, estimated workforce HIV prevalence ranged from 5%¬37%. The average cost per employee lost to AIDS varied from 0.5-5.6 times the average annual compensation of the employee affected. Labor cost increases as a result of AIDS were estimated at anywhere from 0.6%-10.8% but exceeded 3% at only 2 of 14 companies. Treatment of eligible employees with ART at a cost of $360/patient/year was shown to have positive financial returns for most but not all companies. Uptake of employer-provided testing and treatment services varied widely. Among SMEs, HIV prevalence in the workforce was estimated at 10%-26%. SME managers consistently reported low AIDS-related employee attrition, little concern about the impacts of AIDS on their companies, and relatively little interest in taking action, and fewer than half had ever discussed AIDS with their senior staff. AIDS was estimated to increase the average operating costs of small tourism companies in Zambia by less than 1%; labor cost increases in other sectors were probably smaller. Conclusions: Although there was wide variation among the firms studied, clear patterns emerged that will permit some prediction of impacts and responses in the future.
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This study has considered the optimisation of granola breakfast cereal manufacturing processes by wet granulation and pneumatic conveying. Granola is an aggregated food product used as a breakfast cereal and in cereal bars. Processing of granola involves mixing the dry ingredients (typically oats, nuts, etc.) followed by the addition of a binder which can contain honey, water and/or oil. In this work, the design and operation of two parallel wet granulation processes to produce aggregate granola products were incorporated: a) a high shear mixing granulation process followed by drying/toasting in an oven. b) a continuous fluidised bed followed by drying/toasting in an oven. In high shear granulation the influence of process parameters on key granule aggregate quality attributes such as granule size distribution and textural properties of granola were investigated. The experimental results show that the impeller rotational speed is the single most important process parameter which influences granola physical and textural properties. After that binder addition rate and wet massing time also show significant impacts on granule properties. Increasing the impeller speed and wet massing time increases the median granule size while also presenting a positive correlation with density. The combination of high impeller speed and low binder addition rate resulted in granules with the highest levels of hardness and crispness. In the fluidised bed granulation process the effect of nozzle air pressure and binder spray rate on key aggregate quality attributes were studied. The experimental results show that a decrease in nozzle air pressure leads to larger in mean granule size. The combination of lowest nozzle air pressure and lowest binder spray rate results in granules with the highest levels of hardness and crispness. Overall, the high shear granulation process led to larger, denser, less porous and stronger (less likely to break) aggregates than the fluidised bed process. The study also examined the particle breakage of granola during pneumatic conveying produced by both the high shear granulation and the fluidised bed granulation process. Products were pneumatically conveyed in a purpose built conveying rig designed to mimic product conveying and packaging. Three different conveying rig configurations were employed; a straight pipe, a rig consisting two 45° bends and one with 90° bend. Particle breakage increases with applied pressure drop, and a 90° bend pipe results in more attrition for all conveying velocities relative to other pipe geometry. Additionally for the granules produced in the high shear granulator; those produced at the highest impeller speed, while being the largest also have the lowest levels of proportional breakage while smaller granules produced at the lowest impeller speed have the highest levels of breakage. This effect clearly shows the importance of shear history (during granule production) on breakage during subsequent processing. In terms of the fluidised bed granulation, there was no single operating parameter that was deemed to have a significant effect on breakage during subsequent conveying. Finally, a simple power law breakage model based on process input parameters was developed for both manufacturing processes. It was found suitable for predicting the breakage of granola breakfast cereal at various applied air velocities using a number of pipe configurations, taking into account shear histories.
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The training and ongoing education of medical practitioners has undergone major changes in an incremental fashion over the past 15 years. These changes have been driven by patient safety, educational, economic and legislative/regulatory factors. In the near future, training in procedural skills will undergo a paradigm shift to proficiency based progression with associated requirements for competence-based programmes, valid, reliable assessment tools and simulation technology. Before training begins, the learning outcomes require clear definition; any form of assessment applied should include measurement of these outcomes. Currently training in a procedural skill often takes place on an ad hoc basis. The number of attempts necessary to attain a defined degree of proficiency varies from procedure to procedure. Convincing evidence exists that simulation training helps trainees to acquire skills more efficiently rather than relying on opportunities in their clinical practice. Simulation provides a safe, stress free environment for trainees for skill acquisition, generalization and transfer via deliberate practice. The work described in this thesis contributes to a greater understanding of how medical procedures can be performed more safely and effectively through education. The effect of feedback, provided to novices in a standardized setting on a bench model, based on knowledge of performance was associated with an increase in the speed of skill acquisition and a decrease in error rate during initial learning. The timing of feedback was also associated with effective learning of skill. A marked attrition of skills (independent of the type of feedback provided) was demonstrable 24 hrs after they have first been learned. Using the principles of feedback as described above, when studying the effect of an intense training program on novices of varied years of experience in anaesthesia (i.e. the present training programmes / courses of an intense training day for one or more procedures). There was a marked attrition of skill at 24 hours with a significant correlation with increasing years of experience; there also appeared to be an inverse relationship between years of experience in anaesthesia and performance. The greater the number of years of practice experience, the longer it required a learner to acquire a new skill. The findings of the studies described in this thesis may have important implications for the trainers, trainees and training bodies in the design and implementation of training courses and the formats of delivery of changing curricula. Both curricula and training modalities will need to take account of characteristics of individual learners and the dynamic nature of procedural healthcare.
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Prenatal well-being can have significant effects on the mother and developing foetus. Positive psychological interventions, including gratitude and mindfulness, consistently demonstrate benefits for well-being in diverse populations. No research has been conducted on gratitude during pregnancy; the few studies of prenatal mindfulness interventions have demonstrated well-being benefits. The current study examined the effects of gratitude and mindfulness interventions on prenatal maternal well-being, cortisol and birth outcomes. Five studies were conducted. Study 1 was a systematic review of mindfulness intervention effects on cortisol; this highlighted potential benefits of mindfulness but the need for rigorous protocols in future research. In Study 2 a gratitude and a mindfulness intervention were developed and evaluated; findings indicate usefulness of two 3 week interventions. Study 3 examined the effects of these interventions in a randomised controlled trial (RCT) of non-pregnant women, before examining a pregnant group. No significant intervention effects were found in this study, potentially due to insufficient power and poor protocol adherence. Changes in expected directions were observed for most outcomes and the potential utility of a combined gratitude and mindfulness intervention was noted. In Study 4 a gratitude during pregnancy (GDP) scale was developed and the reliability of an existing mindfulness measure (MAAS) was examined in a pregnant group. Both scales were found to be suitable and reliable measures in pregnancy. Study 5 incorporated the findings of the previous four studies to examine of the effect of a combined mindfulness and gratitude intervention with a group of pregnant women. Forty-six participants took part in a 5-week RCT that examined intervention effects on prenatal gratitude, mindfulness, happiness, satisfaction with life, social support, prenatal stress, depression and sleep. Findings indicated that the intervention improved sleep quality and that effects for prenatal distress were approaching significance. Issues of attrition and non-compliance to study protocols were problematic and are discussed. In summary, the current thesis highlights the need for robust measurement, and intervention and cortisol sampling protocols in future research, particularly with pregnant groups. Findings also demonstrate tentative benefits of a gratitude and mindfulness intervention during pregnancy.
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Paleoprimatologists depend on relationships between form and function of teeth to reconstruct the diets of fossil species. Most of this work has been limited to studies of unworn teeth. A new approach, dental topographic analysis, allows the characterization and comparison of worn primate teeth. Variably worn museum specimens have been used to construct species-specific wear sequences so that measurements can be compared by wear stage among taxa with known differences in diet. This assumes that individuals in a species tend to wear their molar teeth in similar ways, a supposition that has yet to be tested. Here we evaluate this assumption with a longitudinal study of changes in tooth form over time in primates. Fourteen individual mantled howling monkeys (Alouatta palliata) were captured and then recaptured after 2, 4, and 7 years when possible at Hacienda La Pacifica in Costa Rica between 1989-1999. Dental impressions were taken each time, and molar casts were produced and analyzed using dental topographic analysis. Results showed consistent decreases in crown slope and occlusal relief. In contrast, crown angularity, a measure of surface jaggedness, remained fairly constant except with extreme wear. There were no evident differences between specimens collected in different microhabitats. These results suggest that different individual mantled howling monkeys wear their teeth down in similar ways, evidently following a species-specific wear sequence. Dental topographic analysis may therefore be used to compare morphology among similarly worn individuals from different species.
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In this paper, we address the use of CBR in collaboration with numerical engineering models. This collaborative combination has a particular application in engineering domains where numerical models are used. We term this domain “Case Based Engineering” (CBE), and present the general architecture of a CBE system. We define and discuss the general characteristics of CBE and the special problems which arise. These are: the handling of engineering constraints of both continuous and nominal kind; interpolation over both continuous and nominal variables, and conformability for interpolation. In order to illustrate the utility of the method proposed, and to provide practical examples of the general theory, the paper describes a practical application of the CBE architecture, known as CBE-CONVEYOR, which has been implemented by the authors.Pneumatic conveying is an important transportation technology in the solid bulks conveying industry. One of the major industry concerns is the attrition of powders and granules during pneumatic conveying. To minimize the fraction of particles during pneumatic conveying, engineers want to know what design parameters they should use in building a conveyor system. To do this, engineers often run simulations in a repetitive manner to find appropriate input parameters. CBE-Conveyor is shown to speed up conventional methods for searching for solutions, and to solve problems directly that would otherwise require considerable intervention from the engineer.
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A global shortage of nurses means there is an increasing interest in attrition rates among nursing students. This UK research by Julie Bowden looked at attrition from the perspective of those who almost left, but ultimately stayed. It highlights the importance of the support provided by personal tutors.
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Antecedentes. Pes Adulto planus (pie plano) es un problema común encontrado por muchos profesionales de la salud. A pesar de la percepción de que el pie plano puede causar dolor y deteriorar su función, la disponibilidad y el uso generalizado de diversos tratamientos, no hay consenso sobre la estrategia óptima de tratamiento. Objetivo. Evaluar la efectividad de las intervenciones conservadoras (no quirúrgicos) para pie plano en los adultos. Método. Se realizó una búsqueda sistemática de la literatura. Esto incluye: el Registro Cochrane Central de Ensayos Controlados; los Juicios CMSG Especializados Registro; una búsqueda electrónica se realizó utilizando MEDLINE (1960 a junio de 2012), EMBASE (1980 a junio de 2012), y CINAHL (1982 - junio de 2012). Revistas especializadas, listas de referencias de ensayos y artículos de revisión se realizaron búsquedas manuales. Criterios de selección: Ensayos aleatorios o cuasialeatorios de intervenciones de tratamiento para el pie plano en los adultos. Se excluyeron los ensayos que incluyeron patologías específicas como el dolor plantar del talón, las fracturas por sobrecarga de los metatarsianos, disfunción del tendón tibial posterior-, fracturas de tobillo, patologías del pie reumatoide, enfermedades neuromusculares y las complicaciones del pie diabético. Recopilación y análisis de datos: Dos autores seleccionaron de forma independiente los resultados de la búsqueda para identificar a aquellos que satisfacen los criterios de inclusión y evaluaron la calidad de los incluidos mediante una lista de control basado en la Evaluación de la Colaboración Cochrane de Riesgo. Esta herramienta se centró en el riesgo de la selección, el rendimiento, la detección, la heterogeneidad y el sesgo de notificación. Resultados. Cuatro ensayos, con 140 sujetos, cumplieron los criterios de inclusión para la revisión. Los cuatro fueron juzgados como de alto riesgo de sesgo en al menos un área, y también estaban en riesgo de sesgo incierto en al menos otra zona. Todos anotaron altamente en relación al sesgo de deserción, debido al corto seguimiento tiempos y diseños experimentales utilizados. Los datos no se agruparon debido al alto nivel de heterogeneidad identificada en las intervenciones evaluadas, los participantes seleccionados y medir los resultados. Los resultados de un estudio sugieren que después de cuatro semanas de uso ortesis puede resultar en una mejora significativa en vaivén lateral medio, y pueden resultar en una mejor, aunque no significativa, en general relacionados con la calidad de vida de los pies (Roma 2004). Un estudio (Redmond 2009) sugiere que su efecto sobre la distribución de la presión plantar en el pie puede no depender de si son personalizados o dispositivos prefabricados. Aunque este estudio se identificaron cambios significativos en algunas variables de presión plantar tanto con la costumbre y dispositivos prefabricados, otro (Esterman 2005) no encontró ningún efecto significativo de longitud ¾ ortesis prefabricadas sobre el dolor, la incidencia de lesiones, salud pie o de calidad de vida en un grupo de reclutas de la fuerza aérea. El cuarto estudio (Jung 2009) sugiere que el ejercicio de los músculos intrínsecos del pie puede mejorar el efecto de las ortesis. A pesar de estos resultados, ya que cada estudio incurrió riesgo de sesgo en al menos un área no se pueden sacar conclusiones
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This text presents an analysis of aggregated membership’s dynamics for Spanish trade unions, using ECVT data, as well as union memberships’ trajectories, or members’ decisions about joining the organization, permanency and responsibilities, and subsequent attrition. For the analysis of trajectories we make use of information of the records of actual memberships and the record of quitting of CCOO, and of a survey-questionnaire to a sample of leavers of the same union. This study allows us to confirm a linkage between the decision and motivations to become union member, to participate in union activities, the time of permanency, and the motives to quit the organization. We also identify five types of union members’ trajectories, indicating that, far from views that assert a monolithic structure, unions are complex organizations.
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Anxiety, negative attitudes, and attrition are all issues presented in the teaching of statistics to undergraduates in research-based degrees regardless of location. Previous works have looked at these obstacles, but none have consolidated a multilingual, multinational effort using a consistent method. Over 400 Spanish-, English-, and German-speaking undergraduate students enrolled in introductory psychology statistics courses were given the Composite Survey of Statistics Anxiety and Attitudes to determine the precursors and effects of existing problems. Results indicated that student background was heavily linked to attitudes and anxieties. The measure was supported as a viable method for more than one class or university in addressing issues in statistics education, developing interventions to improve students’ experiences, and then determining the success of those changes.
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Rebellion, philosophic and political, impels the work of Alasdair MacIntyre. Neither of the left nor the right, he treads a borderline path between conservatism and radicalism in holding to a socialist Thomistic Aristotelianism underpinned by a deliberative ‘ethic of care’ that is implacably opposed to modernity and the advanced capitalist nation-state. The depth of this opposition arouses strong opinions in friend and foe alike. To some he is an eminently dispensable reactionary whose sole consistent feature is an inexplicable ‘hatred of liberal individualism’ (Lessnoff 1999: 4). To others he appears a revolutionary enunciating a departure capable of legitimating the activities of ordinary persons so ‘that previously isolated struggles might be transformed into a new class war of attrition’ (Knight 1996: 896). However, neither interpretation rings true. MacIntyre does develop a cogent critique of the present, but this critique points in directions towards which no politics could hope to move.
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This paper describes a randomised controlled trial (RCT) investigation of the added value of systemic family therapy (SFT) over individually focused cognitive behavioural therapy (CBT) for families in which one or more members has suffered trauma and been referred to a community-based psychotherapy centre. The results illustrate how an apparently robust design can be confounded by high attrition rates, low average number of therapeutic sessions and poor protocol adherence. The paper highlights a number of general and specific lessons regarding the resources and processes involved that can act as a model for those planning to undertake studies of this type and scope. A key message is that the challenges of conducting RCTs in ‘real world’ settings should not be underestimated. The wider implications in relation to the place of RCTs within the creation of the evidence base for complex psycho-social interventions is discussed and the current movement towards a phased mixed-methods approach, including the appropriate use of RCTs, which some might argue is a return to the original vision of evidence-based practice (EBP), is affirmed.
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Excretory secretory products (ESP) of Schistosoma mansoni developing larvae are ideal potential vaccines as such molecules may readily induce host primary immune responses, and local memory immune response effectors that would target, surround, and pursue the larvae while negotiating the lung blood capillaries. We herein characterized the cytokines response ESP, e.g., SG3PDH, 14-3-3-like protein, TPX, and calpain induce in the natural context of infection, and defined the global cytokine profile conducive to effective schistosome larvae killing. Accordingly, spleen cells (SC) taken from naive, and 7-, or 9-day S. mansoni-infected mice were stimulated in vitro with the selected ESP, in a recombinant or multiple antigen peptide (MAP) form, and examined for production of T helper type (Th) 1, Th2, and Th17 cytokines, and the ability to mediate in vitro attrition of lung-stage schistosomula. The study indicated that larval ESP principally elicit Th1 and Th17 type cytokines. Recombinant SG3PDH was the only test ESP to additionally activate SC from S. mansoni-infected BALB/c mice to release higher IL-4 levels than unstimulated SC and mediate significant (P
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Generally, the solid and liquid fractions (digestate) from Anaerobic Digestion (AD) energy production are considered as waste. This has a negative impact on the sustainability of AD processes because of the financial outlay required to treat digestate before being discharged into municipal water treatment plants or natural water bodies. The main aim of this research was to investigate feasibility of producing an organic fertiliser using anaerobic digestate and limestone powders as the raw materials employing a high shear granulation process. Two-level factorial experimental design was used to determine the influence of granulation process variables on, the strength, resistance to attrition and yield of the granules. It was concluded from the study that it is technically feasible to produce organic fertiliser granules of acceptable strength and product yield. Increasing the liquid-to-solid ratio during granulation leads to increased granule strength and better product yield. Although the strength of the granules produced was lower than typical strength of commercial synthetic fertiliser granules (about 5 to 7. MPa), this could be improved by mixing the digestate with a polymeric binder or coating the particles post granulation. © 2012 Elsevier B.V.
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BACKGROUND: Open angle glaucoma (OAG) is the commonest cause of irreversible blindness worldwide. OBJECTIVES: To study the relative effects of medical and surgical treatment of OAG. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 1, 2005), MEDLINE (1966 to February 2005), EMBASE (1988 to February 2005), and reference lists of articles. We also contacted researchers in the field. SELECTION CRITERIA: Randomised controlled trials comparing medications to surgery in adults. DATA COLLECTION AND ANALYSIS: Two authors independently assessed trial quality and extracted data. We contacted trial investigators for missing information. MAIN RESULTS: Four trials involving 888 participants with previously untreated OAG were included. Surgery was Scheie's procedure in one trial and trabeculectomy in three trials. In three trials, primary medication was usually pilocarpine, in one trial a beta-blocker.In the most recent trial, participants with mild OAG, progressive visual field (VF) loss, after adjustment for cataract surgery, was not significantly different for medications compared to trabeculectomy (Odds ratio (OR) 0.74; 95% CI 0.54 to 1.01). Reduction of vision, with a higher risk of developing cataract (OR 2.69, 95%% CI 1.64 to 4.42), and more patient discomfort was more likely with trabeculectomy than medication.There is some evidence, from three trials, for people with moderately advanced glaucoma that medication is associated with more progressive VF loss and 6 to 8 mmHg less intraocular pressure (IOP) lowering than surgery, either by a Scheie's procedure or trabeculectomy. There was a trend towards an increased risk of failed IOP control over time for initial pilocarpine treatment compared to trabeculectomy. In the longer-term (two trials) the risk of failure was significantly greater with medication than trabeculectomy (OR 3.90, 95% CI 1.60 to 9.53; HR 7.27, 95% CI 2.23 to 25.71). Medicine and surgery have evolved since these trials were undertaken, and additionally the evidence is potentially subject to detection and attrition bias. AUTHORS' CONCLUSIONS: Evidence from one trial suggests, for mild OAG, that VF deterioration up to five-years is not significantly different whether treatment is initiated with medication or trabeculectomy. Reduced vision, cataract and eye discomfort are more likely with trabeculectomy. There is some evidence, for more severe OAG, that initial medication (pilocarpine, now rarely used as first line medication) is associated with greater VF deterioration than surgery. In general, surgery lowers IOP more than medication.There was no evidence to determine the effectiveness of contemporary medication (prostaglandin analogues, alpha2-agonists and topical carbonic anhydrase inhibitors) compared to surgery in severe OAG, and in people of black African ethnic origin who have a greater risk of more severe open angle glaucoma. More research is required.