42 resultados para PID tuning. PID auto-tuning. Evaluation of control loops. Relay method. PID controllers
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Workspace analysis and optimization are important in a manipulator design. As the complete workspace of a 6-DOF manipulator is embedded into a 6-imensional space, it is difficult to quantify and qualify it. Most literatures only considered the 3-D sub workspaces of the complete 6-D workspace. In this paper, a finite-partition approach of the Special Euclidean group SE(3) is proposed based on the topology properties of SE(3), which is the product of Special Orthogonal group SO(3) and R^3. It is known that the SO(3) is homeomorphic to a solid ball D^3 with antipodal points identified while the geometry of R^3 can be regarded as a cuboid. The complete 6-D workspace SE(3) is at the first time parametrically and proportionally partitioned into a number of elements with uniform convergence based on its geometry. As a result, a basis volume element of SE(3) is formed by the product of a basis volume element of R^3 and a basis volume element of SO(3), which is the product of a basis volume element of D^3 and its associated integration measure. By this way, the integration of the complete 6-D workspace volume becomes the simple summation of the basis volume elements of SE(3). Two new global performance indices, i.e., workspace volume ratio Wr and global condition index GCI, are defined over the complete 6-D workspace. A newly proposed 3 RPPS parallel manipulator is optimized based on this finite-partition approach. As a result, the optimal dimensions for maximal workspace are obtained, and the optimal performance points in the workspace are identified.
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OBJECTIVES: To test the effect of an adapted U.S. model of pharmaceutical care on prescribing of inappropriate psychoactive (anxiolytic, hypnotic, and antipsychotic) medications and falls in nursing homes for older people in Northern Ireland (NI).
DESIGN: Cluster randomized controlled trial.
SETTING: Nursing homes randomized to intervention (receipt of the adapted model of care; n=11) or control (usual care continued; n=11).
PARTICIPANTS: Residents aged 65 and older who provided informed consent (N=334; 173 intervention, 161 control).
INTERVENTION: Specially trained pharmacists visited intervention homes monthly for 12 months and reviewed residents' clinical and prescribing information, applied an algorithm that guided them in assessing the appropriateness of psychoactive medication, and worked with prescribers (general practitioners) to improve the prescribing of these drugs. The control homes received usual care.
MEASUREMENTS: The primary end point was the proportion of residents prescribed one or more inappropriate psychoactive medicine according to standardized protocols; falls were evaluated using routinely collected falls data mandated by the regulatory body for nursing homes in NI.
RESULTS: The proportion of residents taking inappropriate psychoactive medications at 12 months in the intervention homes (25/128, 19.5%) was much lower than in the control homes (62/124, 50.0%) (odds ratio=0.26, 95% confidence interval=0.14–0.49) after adjustment for clustering within homes. No differences were observed at 12 months in the falls rate between the intervention and control groups.
CONCLUSION: Marked reductions in inappropriate psychoactive medication prescribing in residents resulted from pharmacist review of targeted medications, but there was no effect on falls.
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Protection against Fasciola hepatica in goats immunized with Peroxiredoxin (Prx) was assessed. The experimental trial consisted of three groups of seven animals: group 1 were unimmunized and uninfected, group 2 were immunized with adjuvant only and group 3 were immunized with recombinant Prx in adjuvant (immunized and infected). Immunization with Prx in Quil A adjuvant, group 3, induced a reduction in fluke burden of 33.04% when compared to adjuvant control, group 2, although this difference was not significant. The hepatic gross and microscopical morphometric study revealed lower damage in the Prx-immunized compared to group 2 (p
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Reproductive performance in the high-yielding dairy cow has severely decreased in the last 40 yr. The aim of this study was to compare the effectiveness of 4 nutritional strategies in improving the reproductive performance of high-yielding dairy cows. It was hypothesized that offering cows a high-starch ration in early lactation would enhance the onset of luteal activity, and that decreasing the severity of negative energy balance in the early postcalving period would improve reproductive parameters. Nutritional regimens aimed at improving fertility were applied to 96 Holstein-Friesian dairy animals. Upon calving, animals were allocated in a balanced manner to one of 4 dietary treatments. Primiparous animals were balanced according to live weight, body condition score and calving date. Multiparous animals were balanced according to parity, previous lactation milk yield, liveweight, body condition score and calving date. Treatment 1 was based on an industry best practice diet (control) to contain 170 g of crude protein/kg of dry matter. Treatment 2 was an individual cow feeding strategy, whereby the energy balance (EB) of individual animals was managed so as to achieve a predetermined target daily EB profile (+/- 10 MJ/d). Treatment 3 was a high-starch/high-fat combination treatment, whereby an insulinogenic (high-starch) diet was offered in early lactation to encourage cyclicity and followed by a lipogenic (low-starch, high-fat) diet to promote embryo development. Treatment 4 was a low-protein diet, containing 140 g of crude protein/kg of dry matter, supplemented with protected methionine at an inclusion level of 40 g per animal per day. The nutritional strategies implemented in this study had no statistically significant effects on cow fertility measures, which included the onset of luteal activity, conception rate, in-calf rate, and the incidence of atypical cycles. The individual cow feeding strategy improved EB in early lactation but had no benefit on conception rate to first insemination. However, conception rate to second insemination, 100-d pregnancy rate (from the commencement of breeding), and overall pregnancy rate tended to be higher in this group. The high-starch/high-fat treatment tended to decrease the proportion of delayed ovulations and increase the proportion of animals cycling by d 50 postcalving. Animals that failed to conceive to first insemination had a significantly longer luteal phase in the first cycle postpartum and a longer inter-ovulatory interval in the second cycle postpartum. With regards to estrous behavior, results indicate that as the size of the sexually active group increased, the intensity of estrus and the expression of mounting or attempting to mount another cow also increased. Furthermore, cows that became pregnant displayed more intense estrous behavior than cows that failed to become pregnant.
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Immunoaffinity chromatography (IAC) and affinity chromatography (AC:) are widely used for extraction of drugs from biological samples. Fifteen column types were purchased from five different manufacturers and;their ability to bind specific drugs including beta-agonists and anabolic steroids over a range of analyte concentrations in fortified bovine urine samples was assessed. The performance data obtained from these columns were compared with columns produced in this laboratory (in house columns). The in house columns gave the highest recoveries, ranging from 92 to 100% at the 1 ng spiking concentration, for five of the seven analytes assessed. Forty percent (11 of 27) of all the commercial column assessments recorded recoveries of less than 50% even when the lowest spiking concentration was applied (1 ng). For one manufacturer, only one of seven different columns purchased delivered extraction efficiencies greater than 50%. The extraction efficiencies of the clenbuterol columns were the highest with all commercially prepared columns showing at least 50% binding of radiolabelled tracer. Recoveries of alpha-nortestosterone were the lowest. The variability of these products with respect to quality control requires constant monitoring.
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The educational impact of a distance learning (DL) course entitled ''Health Screening for Health Promotion, was investigated using a telephone questionnaire survey. An introduction to the DL course was distributed to all community pharmacists in England (16,400); the main body of the course, on which pharmacists were examined, was distributed free of charge to all pharmacists who requested it (1,485). Pharmacists participating in the survey (868) were organized by random selection into groups and stratified according to age, sex and postcode. A matched control group was randomly drawn from those pharmacists who had not participated in the course. The DL course improved pharmacists' knowledge about health screening/health promotion issues (e.g., mean score of 66 percent achieved by a group who had completed the course; 51 percent achieved by the control group; P<0.001). Factors influencing score achieved included sex and year of registration. Males performed better than females (P<0.008) while performance decreased with number of years on the register (P<0.001).
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This paper presents an evaluation of the use of videoconferencing in learning and teaching in a United Kingdom higher education institution involved in initial teacher education. Students had the opportunity to observe naturalistic teaching practices without physically being present in the classroom. The study consisted of semi-structured interviews with the co-ordinator of the link, the head of ICT services in Stranmillis University College and the teacher of the classroom being observed. Students were invited to complete an online questionnaire. The views of the students, the co-ordinator of the link, the teacher of the classroom being observed and the head of ICT services in Stranmillis University College were then triangulated to gain an overall view of the effectiveness of the videoconferencing link. Interviews suggested students benefited in terms of pedagogy. In the early stages of the project, the teacher thought it acted as a form of classroom control. Technical problems were encountered initially and camera control was modified in the light of these. The online questionnaire suggested that students viewed this experience in a positive way and were impressed with the content, technical quality, and potential benefits of the use of this example of new technologies.
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Tutoring is commonly employed to prevent early reading failure, and evidence suggests that it can have a positive effect. This article presents findings from a large-scale (n = 734) randomized controlled trial evaluation of the effect of Time to Read—a volunteer tutoring program aimed at children aged 8 to 9 years—on reading comprehension, self-esteem, locus of control, enjoyment of learning, and future aspirations. The study found that the program had only a relatively small effect on children’s aspirations (effect size +0.17, 95% confidence interval [0.015, 0.328]) and no other outcomes. It is suggested that this lack of evidence found may be due to misspecification of the program logic model and outcomes identified and program-related factors, particularly the low dosage of the program.
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Objectives: To evaluate the effectiveness of (1) dissemination strategies to improve clinical practice behaviors (eg, frequency and documentation of pain assessments, use of pain medication) among health care team members, and (2) the implementation of the pain protocol in reducing pain in long term care (LTC) residents. Design: A controlled before-after design was used to evaluate the effectiveness of the pain protocol, whereas qualitative interviews and focus groups were used to obtain additional context-driven data. Setting: Four LTC facilities in southern Ontario, Canada; 2 for the intervention group and 2 for the control group. Participants: Data were collected from 200 LTC residents; 99 for the intervention and 101 for the control group. Intervention: Implementation of a pain protocol using a multifaceted approach, including a site working group or Pain Team, pain education and skills training, and other quality improvement activities. Measurements: Resident pain was measured using 3 assessment tools: the Pain Assessment Checklist for Seniors with Limited Ability to Communicate, the Pain Assessment in the Communicatively Impaired Elderly, and the Present Pain Intensity Scale. Clinical practice behaviors were measured using a number of process indicators; for example, use of pain assessment tools, documentation about pain management, and use of pain medications. A semistructured interview guide was used to collect qualitative data via focus groups and interviews. Results: Pain increased significantly more for the control group than the intervention group over the 1-year intervention period. There were significantly more positive changes over the intervention period in the intervention group compared with the control group for the following indicators: the use of a standardized pain assessment tool and completed admission/initial pain assessment. Qualitative findings highlight the importance of reminding staff to think about pain as a priority in caring for residents and to be mindful of it during daily activities. Using onsite champions, in this case advanced practice nurses and a Pain Team, were key to successfully implementing the pain protocol. Conclusions: These study findings indicate that the implementation of a pain protocol intervention improved the way pain was managed and provided pain relief for LTC residents.
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Aim - To describe a new method of evaluating the topographic distribution of fundus autofluorescence in eyes with retinal disease. Methods - Images of fundus autofluorescence were obtained in five patients and 34 normal volunteers using a confocal scanning laser ophthalmoscope (cSLO). To evaluate the topographic distribution of fundus autofluorescence throughout the posterior pole a rectangular box, 10 x 750 pixels, was used as the area of analysis. The box was placed, horizontally, across the macular region. The intensity of fundus autofluorescence of each pixel within the rectangular box was plotted against its degree of eccentricity. Profiles of fundus autofluorescence from patients were compared with those obtained from the age matched control group and with cSLO images. Results - Profiles of fundus autofluorescence appeared to represent the topographic distribution of fundus autofluorescence throughout the posterior pole appreciated in the cSLO images, and allowed rapid identification and quantification of areas of increased or decreased fundus autofluorescence. Conclusions - Fundus autofluorescence profiles appear to be useful to study the spatial distribution of fundus autofluorescence in eyes with retinal disease.
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Purpose: To evaluate the clinical and histological side effects of a prototype stereotactic radiotherapy system delivering microcollimated external beam radiation through pars plana in porcine eyes.
Methods: Five Yucatan mini-swine (10 eyes) were randomized to five treatment groups. Eight eyes were dosed with X-ray radiation on Day 1, and two eyes served as untreated controls. Treated eyes received doses up to 60 Gy to the retina and up to 130 Gy to the sclera using single or overlapping beams. The treatment beams were highly collimated such that the diameter was approximately 2.5 mm on the sclera and 3 mm on the retinal surface. Fundus photography, fluorescein angiography (FA), and spectral domain optical coherence tomography (SD-OCT) were obtained on days 7, 30, 60, and 110. Images were examined by a masked grader and evaluated for abnormalities. Animals were sacrificed on day 111 and gross and histopathological analysis was conducted.
Results: Histological and gross changes to eye structures including conjunctiva and lens were minimal at all doses. Fundus, FA, and SD-OCT of the targeted region failed to disclose any abnormality in the control or 21 Gy treated animals. In the 42 and 60 Gy animals, hypopigmented spots were noted after treatment on clinical exam, and corresponding hyperfluorescent staining was seen in late frames. No evidence of choroidal hypoperfusion was seen. The histological specimens from the 60 Gy animals showed photoreceptor loss and displacement of cone nuclei.
Conclusion: Transcleral stereotactic radiation dosing in porcine eyes can be accomplished with no significant adverse events as doses less than 42 Gy.
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Our review of paleoclimate information for New Zealand pertaining to the past 30,000 years has identified a general sequence of climatic events, spanning the onset of cold conditions marking the final phase of the Last Glaciation, through to the emergence to full interglacial conditions in the early Holocene. In order to facilitate more detailed assessments of climate variability and any leads or lags in the timing of climate changes across the region, a composite stratotype is proposed for New Zealand. The stratotype is based on terrestrial stratigraphic records and is intended to provide a standard reference for the intercomparison and evaluation of climate proxy records. We nominate a specific stratigraphic type record for each climatic event, using either natural exposure or drill core stratigraphic sections. Type records were selected on thebasis of having very good numerical age control and a clear proxy record. In all cases the main proxy of the type record is subfossil pollen. The type record for the period from ca 30 to ca 18 calendar kiloyears BP (cal. ka BP) is designated in lake-bed sediments from a small morainic kettle lake (Galway tarn) in western South Island. The Galway tarn type record spans a period of full glacial conditions (Last Glacial Coldest Period, LGCP) within the Otira Glaciation, and includes three cold stadials separated by two cool interstadials. The type record for the emergence from glacial conditions following the termination of the Last Glaciation (post-Termination amelioration) is in a core of lake sediments from a maar (Pukaki volcanic crater) in Auckland, northern North Island, and spans from ca 18 to 15.64±0.41 cal. ka BP. The type record for the Lateglacial period is an exposure of interbedded peat and mud at montane Kaipo bog, eastern North Island. In this high-resolution type record, an initial mild period was succeeded at 13.74±0.13 cal. ka BP by a cooler period, which after 12.55±0.14 cal. ka BP gave way to a progressive ascent to full interglacial conditions that were achieved by 11.88±0.18 cal. ka BP. Although a type section is not formally designated for the Holocene Interglacial (11.88±0.18 cal. ka BP to the present day), the sedimentary record of Lake Maratoto on the Waikato lowlands, northwestern North Island, is identified as a prospective type section pending the integration and updating of existing stratigraphic and proxy datasets, and age models. The type records are interconnected by one or more dated tephra layers, the ages of which are derived from Bayesian depositional modelling and OxCal-based calibrations using the IntCal09 dataset. Along with the type sections and the Lake Maratoto record, important, well-dated terrestrial reference records are provided for each climate event. Climate proxies from these reference records include pollen flora, stable isotopes from speleothems, beetle and chironomid fauna, and glacier moraines. The regional composite stratotype provides a benchmark against which to compare other records and proxies. Based on the composite stratotype, we provide an updated climate event stratigraphic classification for the New Zealand region. © 2013 Elsevier Ltd.