888 resultados para paradigm shift


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The aims of this study were to assess and compare the methodological quality of Cochrane and non-Cochrane systematic reviews (SRs) published in leading orthodontic journals and the Cochrane Database of Systematic Reviews (CDSR) using AMSTAR and to compare the prevalence of meta-analysis in both review types. A literature search was undertaken to identify SRs that consisted of hand-searching five major orthodontic journals [American Journal of Orthodontics and Dentofacial Orthopedics, Angle Orthodontist, European Journal of Orthodontics, Journal of Orthodontics and Orthodontics and Craniofacial Research (February 2002 to July 2011)] and the Cochrane Database of Systematic Reviews from January 2000 to July 2011. Methodological quality of the included reviews was gauged using the AMSTAR tool involving 11 key methodological criteria with a score of 0 or 1 given for each criterion. A cumulative grade was given for the paper overall (0-11); an overall score of 4 or less represented poor methodological quality, 5-8 was considered fair and 9 or greater was deemed to be good. In total, 109 SRs were identified in the five major journals and on the CDSR. Of these, 26 (23.9%) were in the CDSR. The mean overall AMSTAR score was 6.2 with 21.1% of reviews satisfying 9 or more of the 11 criteria; a similar prevalence of poor reviews (22%) was also noted. Multiple linear regression indicated that reviews published in the CDSR (P < 0.01); and involving meta-analysis (β = 0.50, 95% confidence interval 0.72, 2.07, P < 0.001) showed greater concordance with AMSTAR.

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BACKGROUND In 2007, leading international experts in the field of inflammatory bowel disease (IBD) recommended intravenous (IV) iron supplements over oral (PO) ones because of superior effectiveness and better tolerance. We aimed to determine the percentage of patients with IBD undergoing iron therapy and to assess the dynamics of iron prescription habits (IV versus PO). METHODS We analyzed anonymized data on patients with Crohn's disease and ulcerative colitis extracted from the Helsana database. Helsana is a Swiss health insurance company providing coverage for 18% of the Swiss population (1.2 million individuals). RESULTS In total, 629 patients with Crohn's disease (61% female) and 398 patients with ulcerative colitis (57% female) were identified; mean observation time was 31.8 months for Crohn's disease and 31.0 months for ulcerative colitis patients. Of all patients with IBD, 27.1% were prescribed iron (21.1% in males; 31.1% in females). Patients treated with steroids, immunomodulators, and/or anti-tumor necrosis factor drugs were more frequently treated with iron supplements when compared with those not treated with any medications (35.0% versus 20.9%, odds ratio, 1.94; P < 0.001). The frequency of IV iron prescriptions increased significantly from 2006 to 2009 for both genders (males: from 2.6% to 10.1%, odds ratio = 3.84, P < 0.001; females: from 5.3% to 12.1%, odds ratio = 2.26, P = 0.002), whereas the percentage of PO iron prescriptions did not change. CONCLUSIONS Twenty-seven percent of patients with IBD were treated with iron supplements. Iron supplements administered IV were prescribed more frequently over time. These prescription habits are consistent with the implementation of guidelines on the management of iron deficiency in IBD.

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Aggressive behavior can be classified in hostile and instrumental aggressions (anderson & bushman, 2002). this classification is mostly synonymously used with reactive and proactive aggression, whereas the differences between hostile and instrumental aggression lie on three dimensions, the primary goal, amount of anger and planning and calculation(bushman & anderson, 2001). although there are rating instruments and experimental paradigms to measure hostile aggression, there is no instrument to measure instrumental aggression. the following study will present an account to measure instrumental aggression with an experimental laboratory paradigm. the instrument was firstly tested on two samples of normal young adolescents (n1 = 100; amage. = 19.14; n2 = 60; amage. = 21.46). the first study revealed a strong correlation with a laboratory aggression paradigm measuring hostile aggression, but no correlations with self-reported aggression in the buss and perry questionnaire. these results were replicated in a second study, revealing an additional correlation with aggressive but not adaptive assertiveness. secondly the instrument was part of the evaluation of the reasoning and rehabilitation program r&r2 (ross, hilborn & lidell, 1984) in an institution for male adolescents with adjustment problems in switzerland. the r&r2 is a cognitive behavioral group therapy to reduce antisocial and promote prosocial cognitions and behavior. the treatment group (n= 16; rangeage = 15-17) is compared to a no treatment control group (n=24; rangeage = 17-19) preand post- treatment. further aggressive behavior was surveyed and experimentally measured. hostile rumination, aggressive and adaptive assertiveness, emotional and social competence were included in the measurement to estimate construct validity.

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Magnetic resonance temperature imaging (MRTI) is recognized as a noninvasive means to provide temperature imaging for guidance in thermal therapies. The most common method of estimating temperature changes in the body using MR is by measuring the water proton resonant frequency (PRF) shift. Calculation of the complex phase difference (CPD) is the method of choice for measuring the PRF indirectly since it facilitates temperature mapping with high spatiotemporal resolution. Chemical shift imaging (CSI) techniques can provide the PRF directly with high sensitivity to temperature changes while minimizing artifacts commonly seen in CPD techniques. However, CSI techniques are currently limited by poor spatiotemporal resolution. This research intends to develop and validate a CSI-based MRTI technique with intentional spectral undersampling which allows relaxed parameters to improve spatiotemporal resolution. An algorithm based on autoregressive moving average (ARMA) modeling is developed and validated to help overcome limitations of Fourier-based analysis allowing highly accurate and precise PRF estimates. From the determined acquisition parameters and ARMA modeling, robust maps of temperature using the k-means algorithm are generated and validated in laser treatments in ex vivo tissue. The use of non-PRF based measurements provided by the technique is also investigated to aid in the validation of thermal damage predicted by an Arrhenius rate dose model.

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Early intervention and intensive therapy improve the outcome of neuromuscular rehabilitation. There are indications that where a patient is motivated and premeditates their movement, the recovery is more effective. Therefore, a strategy for patient-cooperative control of rehabilitation devices for upper extremities is proposed and evaluated. The strategy is based on the minimal intervention principle allowing an efficient exploitation of task space redundancies and resulting in user-driven movement trajectories. The patient's effort is taken into consideration by enabling the machine to comply with forces exerted by the user. The interaction is enhanced through a multimodal display and a virtually generated environment that includes haptic, visual and sound modalities.

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BACKGROUND The technique of 5-aminolevulinic acid (5-ALA) tumor fluorescence is increasingly used to improve visualization of tumor tissue and thereby to increase the rate of patients with gross total resections. In this study, we measured the resection volumes in patients who underwent 5-ALA-guided surgery for non-eloquent glioblastoma and compared them with the preoperative tumor volume. METHODS We selected 13 patients who had received a complete resection according to intraoperative 5-ALA induced fluorescence and CRET according to post-operative T1 contrast-enhanced MRI. The volumes of pre-operative contrast enhancing tissue, post-operative resection cavity and resected tissue were determined through shift-corrected volumetric analysis. RESULTS The mean resection cavity (29 cm(3)) was marginally smaller than the pre-operative contrast-enhancing tumor (39 cm(3), p = 0.32). However, the mean overall resection volume (84 cm(3)) was significantly larger than the pre-operative contrast-enhancing tumor (39 cm(3), p = 0.0087). This yields a mean volume of resected 5-ALA positive, but radiological non-enhancing tissue of 45 cm(3). The mean calculated rim of resected tissue surpassed pre-operative tumor diameter by 6 mm (range 0-10 mm). CONCLUSIONS Results of the current study imply that (i) the resection cavity underestimates the volume of resected tissue and (ii) 5-ALA complete resections go significantly beyond the volume of pre-operative contrast-enhancing tumor bulk on MRI, indicating that 5-ALA also stains MRI non-enhancing tumor tissue. Use of 5-ALA may thus enable extension of coalescent tumor resection beyond radiologically evident tumor. The impact of this more extended resection method on time to progression and overall survival has not been determined, and potentially puts adjacent and functionally intact tissue at risk.

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Hippocampal place cells in the rat undergo experience-dependent changes when the rat runs stereotyped routes. One such change, the backward shift of the place field center of mass, has been linked by previous modeling efforts to spike-timing-dependent plasticity (STDP). However, these models did not account for the termination of the place field shift and they were based on an abstract implementation of STDP that ignores many of the features found in cortical plasticity. Here, instead of the abstract STDP model, we use a calcium-dependent plasticity (CaDP) learning rule that can account for many of the observed properties of cortical plasticity. We use the CaDP learning rule in combination with a model of metaplasticity to simulate place field dynamics. Without any major changes to the parameters of the original model, the present simulations account both for the initial rapid place field shift and for the subsequent slowing down of this shift. These results suggest that the CaDP model captures the essence of a general cortical mechanism of synaptic plasticity, which may underlie numerous forms of synaptic plasticity observed both in vivo and in vitro.

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This study of ambulance workers for the emergency medical services of the City of Houston studied the factors related to shiftwork tolerance and intolerance. The EMS personnel work a 24-hour shift with rotating days of the week. Workers are assigned to A, B, C, D shift, each of which rotate 24-hours on, 24-hours off, 24-hours on and 4 days off. One-hundred and seventy-six male EMTs, paramedics and chauffeurs from stations of varying levels of activity were surveyed. The sample group ranged in age from 20 to 45. The average tenure on the job was 8.2 years. Over 68% of the workers held a second job, the majority of which worked over 20 hours a week at the second position.^ The survey instrument was a 20-page questionnaire modeled after the Folkard Standardized Shiftwork Index. In addition to demographic data, the survey tool provided measurements of general job satisfaction, sleep quality, general health complaints, morningness/eveningness, cognitive and somatic anxiety, depression, and circadian types. The survey questionnaire included an EMS-specific scaler of stress.^ A conceptual model of Shiftwork Tolerance was presented to identify the key factors examined in the study. An extensive list of 265 variables was reduced to 36 key variables that related to: (1) shift schedule and demographic/lifestyle factors, (2) individual differences related to traits and characteristics, and (3) tolerance/intolerance effects. Using the general job satisfaction scaler as the key measurement of shift tolerance/intolerance, it was shown that a significant relationship existed between this dependent variable and stress, number of years working a 24-hour shift, sleep quality, languidness/vigorousness. The usual amount of sleep received during the shift, general health complaints and flexibility/rigidity (R$\sp2$ =.5073).^ The sample consisted of a majority of morningness-types or extreme-morningness types, few evening-types and no extreme-evening types, duplicating the findings of Motohashi's previous study of ambulance workers. The level of activity by station was not significant on any of the dependent variables examined. However, the shift worked had a relationship with sleep quality, despite the fact that all shifts work the same hours and participate in the same rotation schedule. ^

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We postulated that neuromuscular disuse results in deleteriously affected tissue-vascular fluid exchange processes and subsequently damages the important oxidative bioenergetic process of intramuscular lipid metabolism. The in-depth research reported in the literature is somewhat limited by the ex vivo nature and sporadic time-course characterization of disuse atrophy and recovery. Thus, an in vivo controlled, localized animal model of disuse atrophy was developed in one of the hindlimbs of laboratory rabbits (employing surgically implanted tetrodotoxin (TTX)-filled mini-osmotic pump-sciatic nerve superfusion system) and tested repeatedly with magnetic resonance (MR) throughout the 2-week period of temporarily induced disuse and during the recovery period (following explantation of the TTX-filled pump) for a period of 3 weeks. Controls consisted of saline/"sham"-implanted rabbit hindlimbs. The validity of this model was established with repeated electrophysiologic nerve conduction testing using a clinically appropriate protocol and percutaneously inserted small needle stimulating and recording electrodes. Evoked responses recorded from proximal (P) and distal (D) sites to the sciatic nerve cuff in the TTX-implanted group revealed significantly decreased (p $<$ 0.001) proximal-to-distal (P/D) amplitude ratios (as much as 50-70% below Baseline/pre-implanted and sham-implanted group values) and significantly increased (p $<$ 0.01) differential latency (PL-DL) values (as much as 1.5 times the pre- and sham-implanted groups). By Day 21 of recovery, observed P/D and PL-DL levels matched Baseline/sham-implemented levels. MRI-determined cross-sectional area (CSA) values of Baseline/pre-implanted, sham- or TTX-implanted, and recovering/explanted and the corresponding contralateral hindlimb tibialis anterior (TA) muscles normalized to tibial bone (TB) CSA (in TA/TB ratios) revealed that there was a significant decline (indicative of atrophic response) from pre- and sham-implanted controls by as much as 20% (p $<$ 0.01) at Day 7 and 50-55% (p $<$ 0.001) at Day 13 of TTX-implantation. In the non-implanted contralaterals, a significant increase (indicative of hypertrophic response) by as much as 10% (p $<$ 0.025) at Day 7 and 27% (p $<$ 0.001) at Day 13 + TTX was found. The induced atrophic/hypertrophic TA muscles were observed to be fully recovered by Day 21 post-explantation as evidenced by image TA/TB ratios. End-point biopsy results from a small group of rabbits revealed comprehensive atrophy of both Type I and Type II fibers, although the heterogeneity of the response supports the use of image-guided, volume-localized proton magnetic resonance spectroscopy (MRS) to noninvasively assess tissue-level metabolic changes. MRS-determined results of a 0.25cc volume of tissue within implanted limb TA muscles under resting/pre-ischemic, ischemic-stressed, and post-ischemic conditions at timepoints during and following disuse atrophy/recovery revealed significantly increased intramuscular spectral lipid levels, as much as 2-3 times (p $<$ 0.01) the Baseline/pre-implanted values at Day 7 and 6-7 times (p $<$ 0.001) at Day 13 + TTX, which approached normal levels (compared to pre- and sham-implanted groups) by Day 21 of post-explanation recovery. (Abstract shortened by UMI.) ^

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This paper will discuss how the gender perspective can be applied to the study of the Early Modern Jesuit China mission. I will show that the category of gender provides a promising research perspective on Sino-Western cultural exchange, for it brings to the forefront important aspects of social life in the “contact zone” of Chinese Christian communities. I will argue that through the intercultural contact initiated by the Jesuit China mission, gender roles started to shift slightly on both sides. On the one hand, the Jesuits adopted the Confucian ideal of the separation of the sexes (nannü zhi bie), building for example separate Churches for women, something unknown in Europe. On the other hand, Chinese Christians were urged to reconsider aspects of their traditional gender norms, when for instance some men left their concubines in order to become Christian. The paper will be divided in three parts. First, it will focus on the history of concepts and discuss what gender relations meant in the context of the Early Modern China mission. Then it will turn to the representation of female religiosity in Jesuit Annual Letters and show how the gender perspective can lead to a re-evaluation this source genre. Finally, it will reflect on how the gender perspective can give us fresh insights into well-known paradigms on Sino-Western relations, taking the accommodation paradigm as an example.