938 resultados para Comparative studies


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BACKGROUND There is great variability for the type of anaesthesia used during TAVI, with no clear consensus coming from comparative studies or guidelines. We sought to detect regional differences in the anaesthetic management of patients undergoing transcatheter aortic valve implantation (TAVI) in Europe and to evaluate the relationship between type of anaesthesia and in-hospital and 1year outcome. METHODS Between January 2011 and May 2012 the Sentinel European TAVI Pilot Registry enrolled 2807 patients treated via a transfemoral approach using either local (LA-group, 1095 patients, 39%) or general anaesthesia (GA-group, 1712 patients, 61%). RESULTS A wide variation in LA use was evident amongst the 10 participating countries. The use of LA has increased over time (from a mean of 37.5% of procedures in the first year, to 57% in last 6months, p<0.01). MI, major stroke as well as in-hospital death rate (7.0% LA vs 5.3% GA, p=0.053) had a similar incidence between groups, confirmed in multivariate regression analysis after adjusting for confounders. Dividing our population in tertiles according to the Log-EuroSCORE we found similar mortality under LA, whilst mortality was higher in the highest risk tertile under GA. Survival at 1year, compared by Kaplan-Meier analysis, was similar between groups (log-rank: p=0.1505). CONCLUSIONS Selection of anaesthesia appears to be more influenced by national practice and operator preference than patient characteristics. In the absence of an observed difference in outcomes for either approach, there is no compelling argument to suggest that operators and centres should change their anaesthetic practice.

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While a remarkable continuity in smallholder agricultural production has been identified, the shift from subsistence orientation towards more wage dependence appears in a different light when analysed under a gender perspective. "Feminisation" has been a catchphrase to characterise some of these processes; however, the debate has been subject to overgeneralisation, and can only inadequately grasp the gender dynamics in what has been referred to as "new ruralities". Illustrated for high-value crop production as an expression of agricultural transition in the Global South, this contribution offers a critical account of the feminisation thesis. Instead of discarding the notion of feminisation, it advocates a reassessment of its potential as a comprehensive framework against which empirical findings can be reflected. While conventional uses of the feminisation thesis have, in their great majority, come up with the conclusion that for women it can always only get worse, I propose a perspective which reveals gains and risks and how they are shared between men and women as they engage in new agricultural labour markets. This perspective rests on a methodology for case-based, comparative studies developed in this paper as a contribution for assessing the nature of agricultural transition and to investigate the qualitative change associated with new ruralities. A distinctive appreciation of the substance of agricultural change for different members of the rural society – namely men and women, but also different men, and different women – is the premise for overcoming barriers to shared development, and for framing effective governance in the context of global development.

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The study of strategic behaviour and the impact of institutions on elections has mainly focused on simple and conventional electoral systems: list-proportional electoral systems (PR) and the plurality vote. Less conventional systems are not on the agenda of comparative studies, even though no less than 30% of countries use unconventional electoral systems for their national parliamentary elections, such as the Single Transferable Vote, PR with majority bonuses, or mixed electoral systems. Often, they provide for unusual combinations of different institutional incentives, and hence to particular actor strategies.

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Background Tumor necrosis factor (TNF) inhibition is central to the therapy of inflammatory bowel diseases (IBD). However, loss of response (LOR) is frequent and additional tests to help decision making with costly anti-TNF Therapy are needed. Methods Consecutive IBD Patients receiving anti-TNF therapy (Infliximab (IFX) or Adalimumab (after IFX LOR) from Bern University Hospital were identified and followed prospectively. Patient whole blood was stimulated with a dose-titration of two triggers of TLR receptors human: TNF and LPS. Median fluorescence intensity of CD62L on the surface of granulocytes was quantified by surface staining with specific antibodies (CD33, CD62L) and flow cytometry and logistic curves to these data permits the calculation of EC50 or the half maximal effective concentration TNF concentration to induce shedding [1]. A shift in the concentration were CD62L shedding occurred was seen before and after the anti-TNF agent administraion which permits to predict the response to the drug. This predicted response was correlated to the clinical evolution of the patients in order to analyze the ability of this test to identify LOR to IFX. Results We collected prospective clinical data and blood samples, before and after anti-TNF agent administration, on 33 IBD patients, 25 Crohn's disease and 8 ulcerative colitis patients (45% females) between June 2012 and November 2013. The assay showed a functional blockade of IFX (PFR) for 22 patients (17 CD and 5 UC) whereas 11 (8 CD and 3 UC) had no functional response (NR) to IFX. Clinical characteristics (e.g. diagnosis, disease location, smoking status, BMI and number of infusions) were no significantly different between predicted PFR and NR. Among the 22 Patients with PRF, only 1 patient was a clinical non responder (LOR to IFX), based on clinical prospective evaluation by IBD gastroenterologists (PJ, AM), and among the 11 predicted NR, 3 had no clinical LOR. Sensitivity of this test was 95% and specificity 73% and AUC adjusted for age and gender was 0.81 (Figure 1). During follow up (median 10 mo, 3–15) 8 “hard” outcomes occured (3 medic. flares, 4 resections and 1 new fistula) 2 in the PFR and 6 in the NR group (25% vs. 75%; p < 0.01). Correlation with clinical response is presented in Figure 2. Figure 1. Figure 2. Correlation clinical response - log EC50 changes: 1 No, 2 partial, 3 complete clinical response. Conclusion CD62L (L-Selectin) shedding is the first validated test of functional blockade of TNF alpha in anti-TNF treated IBD patients and will be a useful tool to guide medical decision on the use of anti-TNF agents. Comparative studies with ATI and trough level of IFX are ongoing. 1. Nicola Patuto, Emma Slack, Frank Seibold and Andrew J. Macpherson, (2011), Quantitating Anti-TNF Functionality to Inform Dosing and Choice of Therapy, Gastroenterology, 140 (5, Suppl. I), S689.

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Ancient lakes are often unusually species rich, mostly as a result of radiation and species-flock formation having taken place in only one or a few of many taxa present. Understanding why some taxa radiate and others do not is at the heart of understanding biodiversity. In this chapter I discuss possible explanations for disproportionally large species numbers in some cichlid fish lineages in East African Great Lakes: the halochromine cichlid fishes in Lakes Victoria and Malawi. I show that speciation rates in this group are higher than in any other lacustrine fish radiation. Against this background, I review hypotheses put forward to explain diversity in cichlid species flocks. The evolution of species diversity requires three processes: speciation, ecological radiation and anatomical diversification, and it is wrong to consider hypotheses that are relevant to different processes as alternatives to each other. The African cichlid species flocks show unusually high ecological species packing in several phylogenetic groups and unusually high speciation rates in haplochromines. Therefore, it maybe concluded that at least two evolutionary models are required to explain the difference between cichlid diversity and other fish diversity in East African Lakes: one for speciation in haplochromines and one for coexistence. Subsequently I review work on speciation in haplochromines, and in particular studies aimed at testing the hypothesis of speciation by sexual selection. Haplochromines have a polygynous mating system, conducive to sexual selection, but other polygynous cichlids are not particularly species rich. This suggests that more than just strong sexual selection is required to explain haplochromine species richness. Recent palaeoecological evidence undermines the previously popular hypotheses that explained the species richness of Lake Victoria in terms of speciation under varying natural or sexual selection regimes in satellite lakes or in isolated lake basins. I summarize experimental and comparative studies, which provide evidence for two mechanisms of sympatric speciation by disruptive sexual selection on polymorphic coloration. Such modes of speciation may explain (i) the high speciation rates in colour polymorphic lineages of haplochromine cichlids under conditions where colour variation is visible in clear water, and (ii) in combination with factors that affect population survival, the unusual species richness in haplochromine species flocks. I argue that sexual selection, if disruptive, can accelerate the pace of adaptive radiation because the resultant genetic population fragmentation allows a much increased rate of differential response to disruptive natural selection. Hence, the ecological pattern of diversity resembles that produced by disruptive natural selection, with the difference that disruptive sexual selection continues to cause (gross) speciation even after niche space is saturated. This may explain the unusually high numbers of very closely related and ecologically similar species in haplochromine species flocks. The role of disruptive sexual selection is twofold: it not only causes speciation, but also maintains reproductive isolation in sympatry between species that have evolved in sympatry or allopatry. Therefore, the maintenance of diversity in species flocks that originated through sexual selection depends on the persistence of the selection regime within the environmental signal space under which that diversity evolved.

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BACKGROUND A rapid review, guided by a protocol, was conducted to inform development of the World Health Organization's guideline on personal protective equipment in the context of the ongoing (2013-present) Western African filovirus disease outbreak, with a focus on health care workers directly caring for patients with Ebola or Marburg virus diseases. METHODS Electronic databases and grey literature sources were searched. Eligibility criteria initially included comparative studies on Ebola and Marburg virus diseases reported in English or French, but criteria were expanded to studies on other viral hemorrhagic fevers and non-comparative designs due to the paucity of studies. After title and abstract screening (two people to exclude), full-text reports of potentially relevant articles were assessed in duplicate. Fifty-seven percent of extraction information was verified. The Grading of Recommendations Assessment, Development and Evaluation framework was used to inform the quality of evidence assessments. RESULTS Thirty non-comparative studies (8 related to Ebola virus disease) were located, and 27 provided data on viral transmission. Reporting of personal protective equipment components and infection prevention and control protocols was generally poor. CONCLUSIONS Insufficient evidence exists to draw conclusions regarding the comparative effectiveness of various types of personal protective equipment. Additional research is urgently needed to determine optimal PPE for health care workers caring for patients with filovirus.

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Perca fluviatilis is a fish species of increasing interest to the Swiss fish farming industry. In recent years, recirculation systems have been specifically set up to increase production. In one of these farms, abnormal spiral swimming associated with elevated mortalities occurred in repeated batches of imported perch shortly after stocking on several occasions. No bacterial or parasitic etiology was detected, but a virus grown in bluegill fry (BF-2) cells was identified as perch rhabdovirus. Subsequent investigations of other samples suggested a viral tropism for the central nervous system (CNS). Phylogenetic analysis of the partial N and entire G gene sequences positioned this isolate in genogroup C of the species Perch rhabdovirus, with high nucleotide and amino acid (aa) sequence identities with the DK5533 strain isolated in Denmark in 1989. Comparative studies using other closely related isolates allowed the distinction of 2 serological Patterns among perch rhabdoviruses and the identification of a proline substitution by a serine in Position 147 of the glycoprotein potentially involved in antigenic differentiation. Even if perch imported onto the farm tested negative by virus isolation prior to transport, they may have been the origin of this outbreak since CNS tissue was not included in the samples that were analyzed. Another possibility might be a sub-clinical infection with a viral load in resident fish too low to be detected. This study reports the first isolation of a perch rhabdovirus in Switzerland, and emphasizes the necessity of optimizing diagnostic tools that facilitate better control of the risks associated with fish translocation.

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Hair cycle disturbances are common in dogs and comparable to some alopecic disorders in humans. A normal hair cycle is maintained by follicular stem cells which are predominately found in an area known as the bulge. Due to similar morphological characteristics of the bulge area in humans and dogs, the shared particularity of compound hair follicles as well as similarities in follicular biomarker expression, the dog is a promising model to study human hair cycle and stem cell disorders. To gain insight into the spatial distribution of follicular keratinocytes with stem cell potential in canine compound follicles, we microdissected hair follicles in anagen and telogen from skin samples of freshly euthanized dogs. The keratinocytes isolated from different locations were investigated for their colony forming efficiency, growth and differentiation potential as well as clonal growth. Our results indicate that i) compound and single hair follicles exhibit a comparable spatial distribution pattern with respect to cells with high growth potential and stem cell-like characteristics, ii) the lower isthmus (comprising the bulge) harbors most cells with high growth potential in both, the anagen and the telogen hair cycle stage, iii) unlike in other species, colonies with highest growth potential are rather small with an irregular perimeter and iv) the keratinocytes derived from the bulbar region exhibit characteristics of actively dividing transit amplifying cells. Our results now provide the basis to conduct comparative studies of normal dogs and those with hair cycle disorders with the possibility to extend relevant findings to human patients.

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The aim of this paper is to provide a review of general processes related to plasma sources, their transport, energization, and losses in the planetary magnetospheres. We provide background information as well as the most up-to-date knowledge of the comparative studies of planetary magnetospheres, with a focus on the plasma supply to each region of the magnetospheres. This review also includes the basic equations and modeling methods commonly used to simulate the plasma sources of the planetary magnetospheres. In this paper, we will describe basic and common processes related to plasma supply to each region of the planetary magnetospheres in our solar system. First, we will describe source processes in Sect. 1. Then the transport and energization processes to supply those source plasmas to various regions of the magnetosphere are described in Sect. 2. Loss processes are also important to understand the plasma population in the magnetosphere and Sect. 3 is dedicated to the explanation of the loss processes. In Sect. 4, we also briefly summarize the basic equations and modeling methods with a focus on plasma supply processes for planetary magnetospheres.

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Opioids are drugs with opium-like qualities that are either derived from opiates (drugs created from opium, such as morphine or codeine) or chemically produced. In the U.S. opiate abuse and related deaths have been increasing and traditional maintenance treatment has been Methadone with variable success. However, since 2003 synthetic Buprenorphine has been used since it is prescribed daily by physicians in pill form and should improve outcomes. Comparative studies are limited and the effect of ethnicity on treatment outcome is unknown. ^ Data collected at one clinic from December 2005 through May 2009 were used to compare the association between ethnicity and other socioeconomic variables with treatment status, and to identify factors associated with the dropout among participants. Descriptive tables and multiple logistic regression models were used to examine the data on 1,295 total participants. Of the total, 875 participants (68%) were from the Methadone subsample and 420 participants (32%) from the Buprenorphine subsample; only about 15% stayed in treatment. ^ This study showed that with either Methadone or Buprenorphine maintenance therapy, only about 15% participants stay active over 3.5 years. Methadone treated patients that stayed active in treatment were associated with Caucasian ethnicity and were more likely to be employed. With Buprenorphine maintenance treatment only age over 40 years was associated with continuing activity in the program. Further studies that examine the reasons for the high dropout status and the implication of the socioeconomic and ethnic associations found in this data may help to improve treatment outcomes.^

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En este trabajo se presentan algunas reflexiones sobre los aportes de la genética textual o crítica genética (Lois, 2001; Goldchluk, 2005; 2009) al comparatismo. Dado que este enfoque propone un trabajo con el proceso de escritura, presupone la comparación entre diferentes estadios textuales; la obra es la suma de los diferentes estadios textuales y momentos de archivación, no sólo el estadio édito para esta perspectiva. El modo de lectura que puede desprenderse de este enfoque permite encontrar en una obra diferentes núcleos de análisis que pueden leerse de modo transversal en diferentes instancias textuales, por lo cual se puede efectuar una lectura que denominaremos «constelada¼. ;Para abordar estas ideas, recurriremos a observaciones surgidas a partir del proyecto de licenciatura que se centra en el estudio de la génesis textual de la obra Amadeus, del dramaturgo inglés Peter Shaffer.

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En este artículo se presentan algunas reflexiones desarrolladas en Argentina sobre los aportes de la genética textual o crítica genética (Lois, 2001, 2005; Goldchluk, 2009, 2010) a los estudios de literatura comparada. Desde esta perspectiva que propone un trabajo con el proceso de escritura, la comparación entre diferentes estadios textuales resulta decisiva; a su vez, el abordaje de una génesis escritural requiere consideraciones teóricas y metodológicas para delimitar el dossier genético (Lois, 2001) en torno a una obra analizada. A su vez, esta perspectiva considera que la obra no sólo es el estadio édito de un texto sino aquello que sucede entre los diferentes estadios textuales. El modo de lectura que puede desprenderse de este enfoque permite encontrar en una obra diferentes núcleos de análisis que pueden leerse de modo transversal en diferentes instancias textuales, por lo cual se puede efectuar una lectura que denominaremos "constelada". Para abordar estas ideas, recurriremos al análisis de la pieza teatral de Peter Shaffer, el cual se enmarca dentro de una investigación actual sobre su génesis. Nos concentraremos en la intertextualidad como problema teórico y la aparición de diferentes motivos en la obra así como las formas en que se retroalimentan

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El estudio de la Iglesia colonial de la campaña de Buenos Aires ha sido abordado desde distintas perspectivas y aristas; desde el análisis de la recolección del diezmo hasta el funcionamiento de una estancia eclesiástica, desde el culto a la virgen de Luján hasta la conformación de cofradías. En este trabajo el tema es la parroquia de Magdalena y sus estrategias de subsistencia económicas en la zona de frontera. Intentado establecer a partir del análisis de los libros de fábrica algunas consideraciones en torno al manejo económico y social de la institución. Se señala la importancia que tiene el reducir la escala de análisis para realizar posibles estudios de comparación en toda la campaña de Buenos Aires y obtener una imagen particular que contribuya a la dilucidación de una imagen general.

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The rationales for comparative studies of guidance systems are outlined. The key differences between guidance systems in different countries can be related to stage of economic development, to the political system, to social and cultural factors, to the education and training system, and to professional and organisational structures. The competing pressures towards convergence and divergence between guidance systems are explored.