933 resultados para Connection designs
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In this note, we show that an extension of a test for perfect ranking in a balanced ranked set sample given by Li and Balakrishnan (2008) to the multi-cycle case turns out to be equivalent to the test statistic proposed by Frey et al. (2007). This provides an alternative interpretation and motivation for their test statistic.
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During the last years two studies for the investigation of the etiology of porcine ear necrosis were carried out at the Clinic for Swine of the University of Veterinary Medicine Vienna. In study 1, parameters, which are discussed in this context, were collected by veterinary practitioners by completing specially designed questionnaires in farms with symptoms of the porcine ear necrosis syndrome. In study 2, samples of piglets and feed were collected for laboratory analysis of the most important infectious agents as well as mycotoxins. In the present manuscript, the results of both projects were compared. Even if the selection criteria of both studies differed, the affected age class was comparable (5.5 to ten weeks of life in study 1 and six to ten weeks of life in study 2). The herd-specific prevalence of the porcine ear necrosis syndrome varied considerably with percentages between 2 and 10, respectively, to 100%. The evaluation of questionnaires in study 1 showed that 51% of the farms had problems with cannibalism. Particles of plant material, which were frequently seen on the histologic slides of study 2, could have got into the tissue by chewing the ears of the pen mates or cannibalism. Whereas in study 1 the negative effect of parameters as high pig density, suboptimal climate, missing enrichment material and bad quality of feed and water were considered, in study 2 all these factors were checked at sample collection and ruled out as precursor for cannibalism. In both studies bacterial agents proved to be a crucial co-factor for the expansion of the necroses to deeper tissue layers, whereas viral pathogens were classified less important. In both projects it was not possible to estimate the direct impact of infectious agents and mycotoxins as direct trigger of the necroses as well as their participation as co-factors or precursor in the sense of an immunosuppression or previous damage of blood vessels or tissue.
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Pelvic lymph node dissection (PLND) in patients with bladder cancer varies widely in extent, technique employed, and pathological workup of specimens. The present paper provides an overview of the existing evidence regarding the effectiveness of PLND and elucidates the interactions between patient, surgeon, pathologist, and treating institution as well as their cumulative impact on the final postoperative lymph node (LN) staging. Bladder cancer patients undergoing radical cystectomy with extended PLND appear to have better oncologic outcomes compared to patients undergoing radical cystectomy and limited PLND. Attempts have been made to define and assess the quality of PLND according to the number of lymph nodes identified. However, lymph node counts depend on multiple factors such as patient characteristics, surgical template, pathological workup, and institutional policies; hence, meticulous PLND within a defined and uniformly applied extended template appears to be a better assurance of quality than absolute lymph node counts. Nevertheless, the prognosis of the patients can be partially predicted with findings from the histopathological evaluation of the PLND specimen, such as the number of positive lymph nodes, extracapsular extension, and size of the largest LN metastases. Therefore, particular prognostic parameters should be addressed within the pathological report to guide the urologist in terms of patient counseling.
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Purpose: The purpose of the Camp For All Connection project is to facilitate access to electronic health information resources at the Camp For All facility. Setting/Participants/Resources: Camp For All is a barrier-free camp working in partnership with organizations to enrich the lives of children and adults with chronic illnesses and disabilities and their families by providing camping and retreat experiences. The camp facility is located on 206 acres in Burton, Texas. The project partners are Texas Woman's University, Houston Academy of Medicine-Texas Medical Center Library, and Camp For All. Brief Description: The Camp For All Connection project placed Internet-connected workstations at the camp's health center in the main lodge and provided training in the use of electronic health information resources. A train-the-trainer approach was used to provide training to Camp For All staff. Results/Outcome: Project workstations are being used by health care providers and camp staff for communication purposes and to make better informed health care decisions for Camp For All campers. Evaluation Method: A post-training evaluation was administered at the end of the train-the-trainer session. In addition, a series of site visits and interviews was conducted with camp staff members involved in the project. The site visits and interviews allowed for ongoing dialog between project staff and project participants.
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Changes in Greenland accumulation and the stability in the relationship between accumulation variability and large-scale circulation are assessed by performing time-slice simulations for the present day, the preindustrial era, the early Holocene, and the Last Glacial Maximum (LGM) with a comprehensive climate model. The stability issue is an important prerequisite for reconstructions of Northern Hemisphere atmospheric circulation variability based on accumulation or precipitation proxy records from Greenland ice cores. The analysis reveals that the relationship between accumulation variability and large-scale circulation undergoes a significant seasonal cycle. As the contributions of the individual seasons to the annual signal change, annual mean accumulation variability is not necessarily related to the same atmospheric circulation patterns during the different climate states. Interestingly, within a season, local Greenland accumulation variability is indeed linked to a consistent circulation pattern, which is observed for all studied climate periods, even for the LGM. Hence, it would be possible to deduce a reliable reconstruction of seasonal atmospheric variability (e.g., for North Atlantic winters) if an accumulation or precipitation proxy were available that resolves single seasons. We further show that the simulated impacts of orbital forcing and changes in the ice sheet topography on Greenland accumulation exhibit strong spatial differences, emphasizing that accumulation records from different ice core sites regarding both interannual and long-term (centennial to millennial) variability cannot be expected to look alike since they include a distinct local signature. The only uniform signal to external forcing is the strong decrease in Greenland accumulation during glacial (LGM) conditions and an increase associated with the recent rise in greenhouse gas concentrations.
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Nuclear factor kappaB (NF-kappaB) and activator protein 1 (AP-1) transcription factors regulate many important biological and pathological processes. Activation of NF-kappaB is regulated by the inducible phosphorylation of NF-kappaB inhibitor IkappaB by IkappaB kinase. In contrast, Fos, a key component of AP-1, is primarily transcriptionally regulated by serum responsive factors (SRFs) and ternary complex factors (TCFs). Despite these different regulatory mechanisms, there is an intriguing possibility that NF-kappaB and AP-1 may modulate each other, thus expanding the scope of these two rapidly inducible transcription factors. To determine whether NF-kappaB activity is involved in the regulation of fos expression in response to various stimuli, we analyzed activity of AP-1 and expression of fos, fosB, fra-1, fra-2, jun, junB, and junD, as well as AP-1 downstream target gene VEGF, using MDAPanc-28 and MDAPanc-28/IkappaBalphaM pancreatic tumor cells and wild-type, IKK1-/-, and IKK2-/- murine embryonic fibroblast cells. Our results show that elk-1, a member of TCFs, is one of the NF-kappaB downstream target genes. Inhibition of NF-kappaB activity greatly decreased expression of elk-1. Consequently, the reduced level of activated Elk-1 protein by extracellular signal-regulated kinase impeded constitutive, serum-, and superoxide-inducible c-fos expression. Thus, our study revealed a distinct and essential role of NF-kappaB in participating in the regulation of elk-1, c-fos, and VEGF expression.
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Factorial designs for clinical trials are often encountered in medical, dental, and orthodontic research. Factorial designs assess two or more interventions simultaneously and the main advantage of this design is its efficiency in terms of sample size as more than one intervention may be assessed on the same participants. However, the factorial design is efficient only under the assumption of no interaction (no effect modification) between the treatments under investigation and, therefore, this should be considered at the design stage. Conversely, the factorial study design may also be used for the purpose of detecting an interaction between two interventions if the study is powered accordingly. However, a factorial design powered to detect an interaction has no advantage in terms of the required sample size compared to a multi-arm parallel trial for assessing more than one intervention. It is the purpose of this article to highlight the methodological issues that should be considered when planning, analysing, and reporting the simplest form of this design, which is the 2 × 2 factorial design. An example from the field of orthodontics using two parameters (bracket type and wire type) on maxillary incisor torque loss will be utilized in order to explain the design requirements, the advantages and disadvantages of this design, and its application in orthodontic research.
Resumo:
Purpose.This retrospective cohort study evaluated factors for peri-implant bone level changes (ΔIBL) associated with an implant type with inner-cone implant-abutment connection, rough neck surface, and platform switching (AT). Materials and Methods. All AT placed at the Department of Prosthodontics of the University of Bern between January 2004 and December 2005 were included in this study. All implants were examined by single radiographs using the parallel technique taken at surgery (T0) and obtained at least 6 months after surgery (T1). Possible influencing factors were analysed first using t-test (normal distribution) or the nonparametric Wilcoxon test (not normal distribution), and then a mixed model q variance analysis was performed. Results. 43 patients were treated with 109 implants. Five implants in 2 patients failed (survival rate: 95.4%).Mean ΔIBL in group 1 (T1: 6–12 months after surgery) was −0.65 ± 0.82mm and −0.69 ± 0.82mm in group 2 (T1: >12 months after surgery) (
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The aim of this study was to improve cage systems for maintaining adult honey bee (Apis mellifera L.) workers under in vitro laboratory conditions. To achieve this goal, we experimentally evaluated the impact of different cages, developed by scientists of the international research network COLOSS (Prevention of honey bee COlony LOSSes), on the physiology and survival of honey bees. We identified three cages that promoted good survival of honey bees. The bees from cages that exhibited greater survival had relatively lower titers of deformed wing virus, suggesting that deformed wing virus is a significant marker reflecting stress level and health status of the host. We also determined that a leak- and drip-proof feeder was an integral part of a cage system and a feeder modified from a 20-ml plastic syringe displayed the best result in providing steady food supply to bees. Finally, we also demonstrated that the addition of protein to the bees' diet could significantly increase the level ofvitellogenin gene expression and improve bees' survival. This international collaborative study represents a critical step toward improvement of cage designs and feeding regimes for honey bee laboratory experiments.
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Numerous studies reported a strong link between working memory capacity (WMC) and fluid intelligence (Gf), although views differ in respect to how close these two constructs are related to each other. In the present study, we used a WMC task with five levels of task demands to assess the relationship between WMC and Gf by means of a new methodological approach referred to as fixed-links modeling. Fixed-links models belong to the family of confirmatory factor analysis (CFA) and are of particular interest for experimental, repeated-measures designs. With this technique, processes systematically varying across task conditions can be disentangled from processes unaffected by the experimental manipulation. Proceeding from the assumption that experimental manipulation in a WMC task leads to increasing demands on WMC, the processes systematically varying across task conditions can be assumed to be WMC-specific. Processes not varying across task conditions, on the other hand, are probably independent of WMC. Fixed-links models allow for representing these two kinds of processes by two independent latent variables. In contrast to traditional CFA where a common latent variable is derived from the different task conditions, fixed-links models facilitate a more precise or purified representation of the WMC-related processes of interest. By using fixed-links modeling to analyze data of 200 participants, we identified a non-experimental latent variable, representing processes that remained constant irrespective of the WMC task conditions, and an experimental latent variable which reflected processes that varied as a function of experimental manipulation. This latter variable represents the increasing demands on WMC and, hence, was considered a purified measure of WMC controlled for the constant processes. Fixed-links modeling showed that both the purified measure of WMC (β = .48) as well as the constant processes involved in the task (β = .45) were related to Gf. Taken together, these two latent variables explained the same portion of variance of Gf as a single latent variable obtained by traditional CFA (β = .65) indicating that traditional CFA causes an overestimation of the effective relationship between WMC and Gf. Thus, fixed-links modeling provides a feasible method for a more valid investigation of the functional relationship between specific constructs.
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Paleogeographic reconstructions of India and Madagascar before their late Cretaceous rifting juxtapose the Antongil Block of Madagascar against the Deccan Traps of India, indicating that the Western Dharwar Craton extends below the Deccan lavas. Some recent studies have suggested that the South Maharashtra Shear Zone along the northern Konkan coast of India limits the northern extent of the Western Dharwar Craton, implying that the craton does not extend below the Deccan Traps, raising a question mark on paleogeographic reconstructions of India and Madagascar. The continuity of the Western Dharwar Craton north of the South Maharashtra Shear Zone below the Deccan Traps—or its lack thereof—is critical for validating tectonic models correlating Madagascar with India. In this study, zircons in tonalitic basement xenoliths hosted in Deccan Trap dykes were dated in situ, using the U-Pb isotope system. The data furnish U-Pb ages that define three populations at 2527 ± 6, 2456 ± 6, and 2379 ± 9 Ma. The 2527 ± 6 Ma ages correspond to the igneous crystallization of the tonalites, whereas the 2456 ± 6 and 2379 ± 9 Ma ages date metamorphic overprints. The results help to establish for the first time that the basement is a part of the Neoarchean granitoid suite of the Western Dharwar Craton, which extends northward up to at least Talvade in central and Kihim beach in the western Deccan. By implication, the South Maharashtra Shear Zone cannot be the northern limit of the Western Dharwar Craton. The granitoids are correlated with the Neoarchean felsic intrusions (2.57–2.49) of the Masaola suite in the Antongil Block of Madagascar, supporting the existence of a Neoarchean Greater Dharwar Craton comprising the Western Dharwar Craton and the Antongil-Masora Block.