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21.
Iván Blanco-Chacón Dionís Remón Camilla Hollanti Montserrat Alsina 《Journal of The Franklin Institute》2014
We develop a new transmission scheme for additive white Gaussian noisy (AWGN) channels based on Fuchsian groups from rational quaternion algebras. The structure of the proposed Fuchsian codes is nonlinear and nonuniform, hence conventional decoding methods based on linearity and symmetry do not apply. Previously, only brute force decoding methods with complexity that is linear in the code size exist for general nonuniform codes. However, the properly discontinuous character of the action of the Fuchsian groups on the complex upper half-plane translates into decoding complexity that is logarithmic in the code size via a recently introduced point reduction algorithm. 相似文献
22.
Giuseppe Lippi Gianfranco Cervellin Camilla Mattiuzzi 《Biochemia medica : ?asopis Hrvatskoga dru?tva medicinskih biokemi?ara / HDMB》2013,23(2):193-200
Background:
A number of preanalytical activities strongly influence sample quality, especially those related to sample collection. Since blood drawing through intravenous catheters is reported as a potential source of erythrocyte injury, we performed a critical review and meta-analysis about the risk of catheter-related hemolysis.Materials and methods:
We performed a systematic search on PubMed, Web of Science and Scopus to estimate the risk of spurious hemolysis in blood samples collected from intravenous catheters. A meta-analysis with calculation of Odds ratio (OR) and Relative risk (RR) along with 95% Confidence interval (95% CI) was carried out using random effect mode.Results:
Fifteen articles including 17 studies were finally selected. The total number of patients was 14,796 in 13 studies assessing catheter and evacuated tubes versus straight needle and evacuated tubes, and 1251 in 4 studies assessing catheter and evacuated tubes versus catheter and manual aspiration. A significant risk of hemolysis was found in studies assessing catheter and evacuated tubes versus straight needle and evacuated tubes (random effect OR 3.4; 95% CI = 2.9–3.9 and random effect RR 1.07; 95% CI = 1.06–1.08), as well as in studies assessing catheter and evacuated tubes versus catheter and manual aspiration of blood (OR 3.7; 95% CI = 2.7–5.1 and RR 1.32; 95% CI = 1.24–1.40).Conclusions:
Sample collection through intravenous catheters is associated with significant higher risk of spurious hemolysis as compared with standard blood drawn by straight needle, and this risk is further amplified when intravenous catheter are associated with primary evacuated blood tubes as compared with manual aspiration. 相似文献23.
Glycogen phosphorylase isoenzyme BB in the diagnosis of acute myocardial infarction: a meta-analysis
Giuseppe Lippi Camilla Mattiuzzi Ivan Comelli Gianfranco Cervellin 《Biochemia medica : ?asopis Hrvatskoga dru?tva medicinskih biokemi?ara / HDMB》2013,23(1):78-82
Background
Early diagnosis is crucial for management of patients with suspected acute myocardial infarction (AMI). Among innovative and promising biomarkers, the recent interest raised on glycogen phosphorylase isoenzyme BB (GPBB) has prompted us to perform a meta-analysis of published studies.Materials and methods:
A systematic electronic search was carried out on PubMed, Web of Science and Google Scholar, with no date restriction, to retrieve all articles that have investigated the early diagnostic performance of GPBB in patients with suspected AMI, and directly reported or allowed calculation of sensitivity and specificity. A meta-analysis of the reported sensitivity and specificity of each study and pooled area under the curve (AUC) was then performed by random effect approach. Heterogeneity was assessed by I-square statistics.Results:
Eight studies were finally selected for analysis (941 subjects; 506 cases and 435 controls), with a high heterogeneity (I-squared, 86.3%). The resulting pooled estimates and 95% confidence interval were 0.854 (0.801–0.891) for sensitivity, 0.767 (0.713–0.815) for specificity, 0.826 (0.774–0.870) for negative predictive value, 0.802 (0.754–0.844) for positive predictive value, and 0.754 (0.602–0.907) for AUC. In those studies that have simultaneously assessed GPBB and a troponin immunoassay, the combination of these biomarkers did not significantly improve the performance of troponin alone.Conclusion:
GPBB does not meet the current requirements for an efficient diagnosis of AMI when used as a stand-alone test, whereas its combination with troponin merits further investigation in larger trials. 相似文献24.
ABSTRACT In Australia, the number of female graduates in some science, technology, engineering, and mathematics (STEM) disciplines is as low as 15%. Previous reviews exploring the issues affecting female undergraduate STEM students are primarily based in North America and there is yet to be an Australian focused review. This review identifies the factors contributing to the gendered experience of Australian undergraduate STEM students. A systematic review was conducted in November – December 2018 using ERIC, PsycInfo, ProQuest and Scopus databases. From this review, 36 papers that focus on gender differences and university STEM students in Australia were identified. The Australian research suggests the most prominent issue for female STEM students is their lower self-efficacy. Gendered preferences for learning, gendered motivations to pursue STEM degrees, the masculine culture of these fields and gender differences in science identity were also themes identified through the review. This review indicates some gaps in the Australian literature, namely that identity, and other emotional factors, are understudied in the Australian context and an avenue for future research. The findings suggest that science educators should be aware of the gendered experiences of their students to ensure female persistence in university STEM degrees. 相似文献
25.
In this empirical study, we investigate an early childhood education activity in mathematics on the concept of ‘pattern’. The children participating in the study attend an intermediate form of schooling in Sweden called ‘the preschool class for six-year-olds’, intended to facilitate their transition from preschool to school. Following a prolonged activity over 45 minutes, we analyse for what the children are supported in discerning and what they give as evidence of having discerned in and about patterns. The theoretical point of departure is variation theory, conceptualising learning as increased discernment. The results show that in terms of the important Vygotskian distinction between ‘pseudo concepts’ and ‘concepts (proper)’, the children's discernment and what they are supported in discerning are of the former kind. Pseudo concepts are discussed as integral to the institutional form of the preschool class and premised to be important to the child's further conceptual development. 相似文献
26.
Abstract The goal of the present study was to examine teaching styles with information and communications technology (ICT); in Italian schools and in particular to explore whether there is a relationship between personal theories of teaching and learning, levels of competence in ICT, and how ICT is integrated into classroom activities. Teachers with high and low levels of competence in ICT were interviewed in order to examine their beliefs, perceptions, and experiences related to teaching with and without the computer. They were asked to reflect both on themselves as teachers and on their pupils. The results of this preliminary study appeared to indicate that both personal theories of teaching and the level of competence with ICT play a major role in how teachers implement ICT and in their perception of their own and their pupils' motivation 相似文献
27.
The 2004 Olympic Games saw a range of judging scandals in the sport of artistic gymnastics that prompted the International Gymnastics Federation to make changes to the sport's judging system. Therefore, following these games, the International Gymnastics Federation reworked the gymnastics scoring system, where the most prominent change was the removal of the ‘perfect 10’ as the highest score possible, to be replaced by an open-ended scoring system. The goal of this paper is to examine the effectiveness of the open-ended system that was introduced in 2006 through examining some of the sport's key values – an approach loosely aligned with broad internalism. It is suggested that the dual purposes of analysing what is achieved and the manner of achieving it are key values of the sport and are differentiated through the way judging utilises two categories known, in gymnastics, as ‘difficulty’ and ‘artistry’. This paper argues that the method of judging ‘difficulty’ is an improvement on previous judging methods. Our analysis of the definition and judging of ‘artistry’ in artistic gymnastics, however, reveals a less certain result. 相似文献
28.
Sofia Johnson Frankenberg Rolf Holmqvist Birgitta Rubenson Camilla Rindstedt 《International Journal of Educational Development》2012
This study presents findings from analyses of naturally occurring literacy events, where children jointly focus on reading and writing letters of the alphabet, illustrating social constructions of learning created through language and embodied action. Video recorded data from two different families living in an urban low-income area in Tanzania is presented to illustrate the findings. The analysis shows how participation frameworks are negotiated in terms of symmetries and asymmetries between younger and older siblings with both older and younger siblings initiating these frameworks: older siblings using different directives to guide the younger child's focus of attention and younger children both following and resisting such strategies. 相似文献
29.
Maria Vetleseter Bøe Ellen Karoline Henriksen Terry Lyons Camilla Schreiner 《Studies in Science Education》2013,49(1):37-72
Young people’s participation in science, technology, engineering and mathematics (STEM) is a matter of international concern. Studies and careers that require physical sciences and advanced mathematics are most affected by the problem and women in particular are under‐represented in many STEM fields. This article views international research about young people’s relationships to, and participation in, STEM subjects and careers through the lens of an expectancy‐value model of achievement‐related choices. In addition it draws on sociological theories of late‐modernity and identity, which situate decision‐making in a cultural context. The article examines how these frameworks are useful in explaining the decisions of young people – and young women in particular – about participating in STEM and proposes possible strategies for removing barriers to participation. 相似文献
30.
Camilla Ferrier 《出版参考》2004,(28):30
编者按:Camilla Ferrier来自于Marsh Agency,这是一家位于伦敦的文字作品代理商,专门负责向欧洲、远东和南美市场销售英国、加拿大及美国作家作品的翻译权.作为版权经理,她的主要工作是确保单行线渠道的畅通--即版权出口的顺畅.以下她从代理公司的角度出发,介绍英国对国外作品英文版的进口状况,以及英国出版的翻译小说数量如此之少的社会和文化原因. 相似文献