682 resultados para Heyliger, Vic


Relevância:

10.00% 10.00%

Publicador:

Resumo:

- Background Sonography is an important diagnostic tool in children with suspected appendicitis. Reported accuracy and appendiceal visualisation rates vary significantly, as does the management of equivocal ultrasound findings. The aim of this study was to audit appendiceal sonography at a tertiary children's hospital, and provide baseline data for a future prospective study. - Summary of work Records of children who underwent ultrasound studies for possible appendicitis between January 2008 and December 2010 were reviewed. Variables included patient demographics, sonographic appendix characteristics, and secondary signs. Descriptive statistics and analysis using ANOVA, Mann-Whitney U test, and ROC curves were performed. Mater Human Research Ethic Committee approval was granted. - Summary of results There were 457 eligible children. Using a dichotomous diagnostic model (including equivocal results), sensitivity was 89.6%, specificity 91.6%, and diagnostic yield of 40.7%. ROC curve analysis of a 6mm diameter cut-off was 0.88 AUC (95% CI 0.80 to 0.95). - Discussion and conclusions Sonography is an accurate test for acute appendicitis in children, with a high sensitivity and negative predictive value. A diameter of 6mm as an absolute cut-off in a binary model can lead to false findings. Results were compared with available literature. Recent publications propose categorising diameter1 and integrating secondary signs2 to improve accuracy and provide more meaningful results to clinicians. This study will be a benchmark for future studies with multiple diagnostic categorisation.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Stress induced by Focused Ion Beam (FIB) milling of cantilevers fabricated on silicon-on-insulator (SOI) wafer has been studied. Milling induces stress gradients ranging from -10MPa/μm to -120MPa/μm, depending on the location of cantilevers from the point of milling. Simulations were done to estimate the stress in the milled cantilevers.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

It has been shown earlier1] that the relaxed force constants (RFCs) could be used as a measure of bond strength only when the bonds form a part of the complete valence internal coordinates (VIC) basis. However, if the bond is not a part of the complete VIC basis, its RFC is not necessarily a measure of bond strength. Sometimes, it is possible to have a complete VIC basis that does not contain the intramolecular hydrogen bond (IMHB) as part of the basis. This means the RFC of IMHB is not necessarily a measure of bond strength. However, we know that IMHB is a weak bond and hence its RFC has to be a measure of bond strength. We resolve this problem of IMHB not being part of the complete basis by postulating `equivalent' basis sets where IMHB is part of the basis at least in one of the equivalent sets of VIC. As long as a given IMHB appears in one of the equivalent complete VIC basis sets, its RFC could be used as a measure of bond strength parameter.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Quantifying the isolated and integrated impacts of land use (LU) and climate change on streamflow is challenging as well as crucial to optimally manage water resources in river basins. This paper presents a simple hydrologic modeling-based approach to segregate the impacts of land use and climate change on the streamflow of a river basin. The upper Ganga basin (UGB) in India is selected as the case study to carry out the analysis. Streamflow in the river basin is modeled using a calibrated variable infiltration capacity (VIC) hydrologic model. The approach involves development of three scenarios to understand the influence of land use and climate on streamflow. The first scenario assesses the sensitivity of streamflow to land use changes under invariant climate. The second scenario determines the change in streamflow due to change in climate assuming constant land use. The third scenario estimates the combined effect of changing land use and climate over the streamflow of the basin. Based on the results obtained from the three scenarios, quantification of isolated impacts of land use and climate change on streamflow is addressed. Future projections of climate are obtained from dynamically downscaled simulations of six general circulation models (GCMs) available from the Coordinated Regional Downscaling Experiment (CORDEX) project. Uncertainties associated with the GCMs and emission scenarios are quantified in the analysis. Results for the case study indicate that streamflow is highly sensitive to change in urban areas and moderately sensitive to change in cropland areas. However, variations in streamflow generally reproduce the variations in precipitation. The combined effect of land use and climate on streamflow is observed to be more pronounced compared to their individual impacts in the basin. It is observed from the isolated effects of land use and climate change that climate has a more dominant impact on streamflow in the region. The approach proposed in this paper is applicable to any river basin to isolate the impacts of land use change and climate change on the streamflow.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The effects of vacuum-induced coherence (VIC) on the properties of the absorption and gain of the probe field in an equispaced three-level ladder atomic system are investigated. It is found that lasing without inversion (LWI) is remarkably enhanced due to the effect of VIC in the case of the small incoherent pump rate.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

细胞分裂素是一类重要的植物激素,它参与调节许多植物的生命活动过程。本文从几个方面研究了细胞分裂素的作用。 在细胞分裂素的活性测定中,通过改进尾穗蔸苋红素合成法建立了一种简便、准确的生物试法,同时还建立了根据物理化学和免疫学原理而测定细胞分裂素的HPLC和ELISA方法,使得细胞分裂素的定量更加准确。经过对上述三种方法的相互验证实验表明,同时采用二种方法可以保证细胞分裂素分析的准确和可靠。 细胞分裂素可以促进黄瓜子叶的扩张。利用离体黄瓜子叶,分析BA诱发其扩张与子叶内源细胞分裂素之间的关系,实验证明,BA能促进玉米素及其核苷的迅速积累,进而诱发子叶的扩张。上述结果还表明,黄瓜子叶可能具有合成细胞分裂素的能力。 荸荠球茎是一种贮藏器官,但实验测定发现其中含有细胞分裂素的生理活性形式——异戊烯基腺嘌呤核苷(iPA),而且合成它的前体腺嘌呤的含量也十分丰富,考虑到球茎与种子的类似之处,推测它可能做为合成细胞分裂素的一个源,而且其合成途径可能有别于植物其它组织。 农杆菌中的异戊烯基转移酶(ipt)基因是负责细胞分裂素生物合成的关键基因。将ipt基因克隆后对其启动子进行了改造,分别构建了如下三种基因:(1) ipt启动子+ipt编码区和3,区(ipt),(2)磷酸核酮糖羧化酶小亚基启动子SSU 301+ipt编码区和3,区(SSU -ipt),(3)豌豆种子特异性启动子viciln+ipt编码区和3,区(vic-ipt)。上述三种基因经农杆菌介导转化烟草,获得了16株再生植株,经Southern杂交证明其中15株的基因组上含有正常整合的ipt基因。Northern杂交表明有13株转基因烟草中的ipt基因能转录出大小正常的ipt mRNA并促进了细胞分裂素的生物合成。 实验表明,转基因烟草中ipt基因的表达受到多种因素的调控。首先启动子决定了ipt基因的表达模式,SSU -ipt基因的表达受光的诱导,黑暗中这种基因的转录完全停止,而vic-ipt基因的表达是种子特异性的,它不在烟草营养生长器官如根、茎、叶和愈伤组织中表达。第二,生长素能降低ipt基因的表达活性。第三,在整体植物的根中,存在某些反式因子,能够控制ipt基因的过量表达,这其中可能涉及到细胞内的蛋白因子、基因的甲基化作用及细胞分裂素的反馈调节等。 vic-ipt基因在烟草种子中的特异性表达导致种子内形成了一个细胞分裂素合成的源(source)。对种子中营养物质积累的研究表明,ipt基因的表达促进了种子干物质的积累,其中作用最明显的是增加种子内蛋白质的合成。转入vic-ipt基因后的烟草种子其萌发率没有显著变化,但幼苗的生长速率明显加快,这表明细胞分裂素能调节植株的生长。 通过Northern杂交检测转基因烟草中基因表达的调控,实验证明,ipt基因的表达明显抑制一组植物病理相关蛋白(PR)基因的转录活性,这组基因编码:几丁质酶,β-1,3一葡萄糖苷酶,伸展蛋白和渗调蛋白。对这些调控作用的生理学意义还有待进一步探索。 上述结果表明,在高等植物中,除了传统上认为根是合成细胞分裂素的部位之外,其它组织和器官也具有合成细胞分裂素的能力,其中合成能力最强的是一些离体组织和贮藏器官。农杆菌中的细胞分裂素生物合成基因(ipt)能够在高等植物的基因组中正常的整合和表达,并受到植物体内生理、发育等多种因素的调控,而与整体植物的正常生理过程协调一致。ipt基因的表达还能够调节植物体的生长和发育,包括种子发育时营养物质的积累、幼苗的生长和某些相关基因的表达。对上述问题的深入研究,必将促进细胞分裂素及其相关生理学和发育学研究的进展。

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In this paper we analyze the representation of the body in blogs by women with breast cancer. Taking into account both texts and images, we study the representation of the body on the basis of the body problems proposed by Frank (1995): control, body-relatedness, other-relatedness and desire. In the blogs studied we find a desiring and dyadic body, which is understood as part of a network of affection and care. The diagnosis of cancer can generate both dissociation, when the body is experienced as a threat, and association, a wish to be connected to it. In relation to control, a clear will of predictability is observed but traces of assumption of contingency also appear.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The ways of incorporating newcoming students into schools and colleges have been at the center of debate in most OECD countries in recent years. In Spain, the set of measures developed for the reception of immigrant pupils in different Autonomous Communities has also been the subject of specific research, pointing out the similarities and contradictions between pedagogic discourses and school practices. This article takes into account these considerations and presents the reflections from the results of research on the Educational Welcome Facilities (and specifically the EBE) conducted during the school years 2008-2010. This device was created in Catalonia to attend newcomers before enrolling them in the school. It was a pilot project which took place in Vic and Reus for two consecutive years. The research of the EBE has enabled us to explain the relationship between educational assessment that schools made about this facility and reception processes that schools were implementing. The conclusions that emerge from this analysis allowed us to establish relationships between educational host practices of the seven centers analyzed with three different conceptual and educational frameworks of reception.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The appearance of the open code paradigm and the demands of social movements have permeated the ways in which today’s cultural institutions are organized. This article analyzes the birth of a new critical and cooperative spatiality and how it is transforming current modes of cultural research and production. It centers on the potential for establishing the new means of cooperation that are being tested in what are defined as collaborative artistic laboratories. These are hybrid spaces of research and creation based on networked and cooperative structures producing a new societal-technical body that forces us to reconsider the traditional organic conditions of the productive scenarios of knowledge and artistic practice.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This paper is concerned with understanding the behaviour of Polyethylene Terephthalate (PET) in the injection stretch blow moulding (ISBM) process where it is typically bi-axially stretched to form bottles for the packaging industry. Preforms which have been pre sprayed with a pattern and heated in an oil bath have been stretched and blown in free air using a lab scale ISBM machine whilst being monitored via high speed video. The images have subsequently been analysed using a digital image correlation system (VIC 3D). Results are presented showing the typical deformation modes and strain rates encountered in the ISBM process.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The injection stretch blow moulding process is used to manufacture PET containers used in the soft drinks and carbonated soft drinks industry. The process consists of a test tube like specimen known as a preform which is heated, stretch and blown into a mould to form the container. This research is focused on developing a validated simulation of the process thus enabling manufacturers to design their products in a virtual environment without the need to waste time, material and energy. The simulation has been developed using the commercial FEA package Abaqus and has been validated using state of the art data acquisition system consisting of measurements for preform temperature (inner and outer wall) using a device known as THERMOscan (Figure 1), stretch rod force and velocity, internal pressure and air temperature inside the preform using an instrumented stretch rod and the?exact?timing of when the preform touches the mould wall using contact sensors.? In addition, validation studies have also been performed by blowing a perform without a mould and using high sped imaging technology in cooperation with an advanced digital image correlation system (VIC 3D) to provided new quantitative information on the behaviour of PET during blowing.? The approach has resulted in a realistic simulation in terms of accurate input parameters, preform shape evolution and prediction of final properties.