1,721,094 research outputs found
Survival of extremely premature babies in a geographically defined population: prospective cohort study of 1994-9 compared with 2000-5
No full textObjective: to assess changes in survival for infants born before 26 completed weeks of gestation. Design: prospective cohort study in a geographically defined population. Setting: former Trent health region of the United Kingdom. Subjects: All infants born at 22+0 to 25+6 weeks' gestation to mothers living in the region. Terminations were excluded but all other births of babies alive at the onset of labour or the delivery process were included. Main outcome measures: outcome for all infants was categorised as stillbirth, death without admission to neonatal intensive care, death before discharge from neonatal intensive care, and survival to discharge home in two time periods: 1994-9 and 2000-5 inclusive. Results: the proportion of infants dying in delivery rooms was similar in the two periods, but a significant improvement was seen in the number of infants surviving to discharge (P<0.001). Of 497 infants admitted to neonatal intensive care in 2000-5, 236 (47%) survived to discharge compared with 174/490 (36%) in 1994. These changes were attributable to substantial improvements in the survival of infants born at 24 and 25 weeks. During the 12 years of the study none of the 150 infants born at 22 weeks' gestation survived. Of the infants born at 23 weeks who were admitted to intensive care, there was no significant improvement in survival to discharge in 2000-5 (12/65 (18%) in 2000-5 v 15/81 (19%) in 1994-9). Conclusions: survival of infants born at 24 and 25 weeks of gestation has significantly increased. Although over half the cohort of infants born at 23 weeks was admitted to neonatal intensive care, there was no improvement in survival at this gestation. Care for infants born at 22 weeks remained unsuccessful.</p
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Monitoring the prenatal detection of structural fetal congenital anomalies in England and Wales: register-based study
No full textObjective: To provide current population-based prevalence and prenatal diagnosis rates (PND) for specified major congenital anomalies in England and Wales to enable monitoring of the Fetal Anomaly Screening Programme (FASP). Design Secondary analysis of prospectively collected registry data. Setting: Seven multiple-source, population-based congenital anomaly registers, members of the British Isles Network of Congenital Anomaly Registers (BINOCAR) in 2005 and 2006. Population: 2,883 births with congenital anomalies from a total of 601,545 live and stillbirths. Main outcome measures: PND and birth prevalence of selected congenital anomaly groups/subtypes (anencephaly, spina-bifida, serious cardiac, diaphragmatic hernia, gastroschisis, exomphalos, bilateral renal agenesis, lethal/severe skeletal dysplasia, cleft lip with or without cleft palate [CL + /–P]). Results: Of the selected anomaly groups, the most frequently reported were serious cardiac (14.1 per 10,000 births [95% CI 13.0–15.2]) and CL + /–P (9.7 per 10,000 births [8.9–10.5]); the least frequent were bilateral renal agenesis and lethal/severe skeletal dysplasia (<1.5 per 10,000 births). The PND varied for different anomalies from 53.1% (95% CI 43.5–65.2) for serious cardiac anomalies to 99.6% (95% CI 97.9–100.0) for anencephaly. Least variation in PND rates was for anencephaly (range 98.9–100%) and gastroschisis (93.5–100%); greatest variation was for serious cardiac (43.5–65.2%) and lethal/severe skeletal dysplasias (50.0–100%). Conclusions: BINOCAR registers can, uniquely, provide contemporary data on PND and birth prevalence rates to enable monitoring of the ultrasound component of FASP at a national and regional level, allowing comparisons between populations to be made, planning of resources facilitated and assistance for parents making informed decisions on whether to enter the screening programme. <br/
Extremely Growth-Retarded Infants: Is There a Viability Centile?
No full textBACKGROUND. It is known that extremely premature infants do less well than more mature infants, and this fact has led some countries to adopt a "cutoff for viability" using birth weight or gestation. Infants affected by intrauterine growth retardation are at additional risk of poor outcome. There are few data to inform decisions about viability and (dis)continuation of intensive care when both extreme prematurity and severe growth retardation are present. OBJECTIVE. We focused on (1) premature infants affected by marked intrauterine growth retardation to determine if there was a cutoff weight centile below which the mortality sharply increased and (2) the short-term outcome of extremely premature and growth-retarded infants to determine a cutoff for viability. METHODS. We evaluated preterm infants of 22-32 weeks' gestation if they were alive at the onset of labor and born to European mothers resident in the Trent (United Kingdom) health region between 1994 and 2003. Infants were categorized into 6 weight centiles, and infants in each category were assessed for survival to discharge from the neonatal unit, duration of respiratory support, length of stay in the neonatal unit, and the age at death in nonsurvivors. RESULTS. We identified a total of 8228 infants who met the study criteria. Of these, 4448 infants were male, 6194 were from singleton pregnancies, and 2887 were born at ≤28 completed weeks of gestation. Survival to discharge was markedly reduced in the infants born at ≤28 weeks of gestation with a birth weight less than the 2nd centile. Stillbirth was inversely related to birth weight centile in infants born before 29 weeks of gestation. CONCLUSIONS. The survival for infants born at ≤28 weeks' gestation and having a birth weight in less than the 2nd centile is poor, and consideration should be given to modifying their management.</p
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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