1,721,169 research outputs found
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
Memoria di un cittadino
No full textla figura e l'impegno civile dello studioso di estetica Emilio Mattioli sono proposti insieme a una scelta dei suoi scritti
Gli autori, in S. Calabrese (a cura di), Narrare al tempo della globalizzazione, Roma, Carocci, 2016, pp. 15-44.
No full textVariations 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
CARATTERIZZAZIONE DI PARAMETRI BIOMETRICI PLACENTARI E FETALI IN GRAVIDANZE DI DONNE OBESE
Full text linkTitle: Placental and Fetal Biometry in Obese Pregnant Women.
Introduction: Placental biometry at birth has been shown to predict chronic disease in later life. Maternal obesity is a risk factor for adverse pregnancy outcomes, possibly because it is characterized by intrauterine low-grade inflammation.
Barker’s hypothesis underlined that the maternal endocrine and nutritional environment can affect fetal metabolism thus the intrauterine environment of an obese woman might establish a pathologic fetal status via placental inflammation, compromising placental function and altering fetal growth and development.
Herein we investigated the placental characteristics in singleton pregnancies of overweight (OW), obese (OB) and normal weight (NW) women.
Sex specific differences in fetal and neonatal morbidity and mortality are well documented.
Differences in birthweight are also recognised, with males generally larger than females at birth and placental weight and F/P weight ratio higher in males compared to females. Sex specific adaptation of the placenta to an external insult may be crucial for the differences in fetal growth and survival.
While the effect of fetal sex on placental development and growth has been studying in depth, sex differences in the context of overnutrition still need to be evaluated.
Thus we studied placental biometry and function in male/female fetuses of OW, OB and NW women.
Methods:
A total of 699 women were enrolled at delivery: 536 were NW (1825 kg/m2), 115 were OW (25BMI<30 kg/m2) and 48 were OB (BMI≥ 30 kg/m2). This study was performed at the Dept of Clinical Sciences, Unit of Obstetrics and Gynecology, L. Sacco Hospital, University of Milan, Italy.
Only singleton pregnancies delivering both by cesarean section and vaginal delivery were enrolled. Exclusion criteria were maternal syndromes, placenta previa, obstetrical complications (preeclampsia, gestational hypertension, gestational diabetes, intrauterine growth retardation, placental abruption), adverse neonatal outcomes, glucose tolerant test positive. Pregnancies carrying fetuses with abnormal karyotype, malformations and infections were also excluded from the study.
Gestational age, maternal data (age, height, BMI, weight gain, hemoglobin -Hb and glucose), fetal data (weight, length, ponderal index and gas analysis at birth) and placental data (weight, larger -D- and smaller -d- diameters) were collected. Placental area was calculated as D x d x π/4. Assuming a constant density, placental thickness was estimated as: weight/area. We expressed placental efficiency using the fetoplacental weight ratio (F/P), calculated as birth weight divided by the placental weight.
Results:
maternal, fetal and placental characteristics in NW vs OW and OB
Fetal weights were significantly higher in the OW and OB groups (3435,00±392,11 gr and 3477,00 ±434,21 gr vs 3344,00±385,71 gr; p<0,05). In the OW group only, placental weights (461,69±93,48 gr vs 434,24±92,47 gr; p<0,01) were higher and the thickness (1,72±0,37 cm vs 1,64±0,36 cm; p<0,05) was significantly increased leading to lower placental efficiency (7,64±1,26 vs 7,96±1,41; p<0,05), represented by lower F/P. OB women presented lower weight gain during pregnancy (8,40±7,30 kg vs 13,50±4,40 kg; p <0,01), lower Hb (11,03±1,18 gr/dl vs 11,46±1,22 gr/dl; p <0,05) and Ht levels (33,16±3,13 % vs 34,27±3,34 %; p<0,05) compared to NW. As expected by the exclusion criteria, there were no differences in the maternal blood glucose concentration in the three groups.
maternal, fetal and placental characteristics in NW vs OW and OB carrying female fetuses and NW vs OW and OB carrying males fetuses
OW and OB with female fetuses presented significantly higher fetal weights (3396,00±341,01 gr and 3516,00±352,05 gr vs 3289,00±379 gr; p<0,05 e p<0,01 respectively), lengths (50,10±1,91 cm and 50,21±1,71 cm vs 49,40±1,77 cm; p<0,05) and head circumferences (34,21±1,27 cm and 34,30±1,21 cm vs 33,69±33,50 cm; p<0,05) compared to NW.
Only OW with females fetuses, presented lower Hb leverls (11,01±1,20 gr/dl vs 11,43±1,25 gr/dl; p<0,05), higher placental weights (477,02±90,61 gr vs 424,03±92,00 gr; p<0,01), higher placental thickness (1,81±0,37 cm vs 1,64±0,39 cm; p<0,05) and lower F/P weights ratio (7,32±1,26 vs 8,01±1,43 p<0,01) compared to NW with female fetuses.
OB with female fetuses only, presented lower weight gain during pregnancy (7,30±8,50 kg vs 13,80±4,70 kg; p<0,01) compared to NW.
On the contrary, OW and OB with male fetuses did not present any of the above mentioned differences compared to NW with male offspring.
maternal, fetal and placental characteristics in male vs female fetuses in the NW, OW and OB group respectively
In the NW group, fetal weights (3391,00±385,01 gr vs 3289,00±379,02 gr; p<0,01), lengths (50,20±1,85 cm vs 49,40±1,77 cm; p<0,01), head circumferences (34,39±1,21 cm vs 33,69±2,50 cm; p<0,01) and placental weights (442,00±91,00 gr vs 424,18±92,30 gr; p<0,05) were higher in male compared to female fetuses.
On the contrary, in the OW and OB groups, fetal weights and lengths were not significantly different between genders, while placental weights tended to be higher and thicker in female compared to male fetuses, leading to lower F/P ratio in female vs male fetuses. Moreover, in the OW group Hb levels were significantly lower in female vs male offspring (11,00±1,21 gr/dl vs 11,60±1,10 gr/dl; p<0,01).
Conclusions:
In our population of non-syndromic OB women, we found lower Hb levels in the maternal blood, possibly accounting for the typical malnutrition of obese women. Interestingly, OW women only, who presented weight gain over the standard recommendation, had thicker and less efficient placentas, probably representing the expression of a higher level of inflammation associated with a worse nutritional status.
We found different placental adaptation in response to low grade inflammation of OB/OW depending on fetal gender, having altered Hb and feto-placental changes only women carrying female fetuses.
These may be part of a strategy aiming to ensure survival in the presence of another adverse event. On the contrary, males approach (without any changes) allows them to continue to growth normally, although expose them to higher risks of fetal complications if another adverse event happens during pregnancy.
Further studies are needed to assess possible correlations between altered placental morphology and placental gene and protein expression involved in the placental exchange in obese women and to provide possible future therapies (i.e. diet) customized according to fetal sex
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
Maternal predictors of intrauterine growth restriction
No full textPURPOSE OF REVIEW: Intrauterine growth restriction (IUGR) occurs when fetal growth rate falls below the genetic potential and affects a significant number of pregnancies, but still no therapy has been developed for this pregnancy disease. This article reviews the most recent findings concerning maternal characteristics and behaviours predisposing to IUGR as well as maternal early markers of the disease. A comprehensive understanding of factors associated with IUGR will help in providing important tools for preventing and understanding adverse outcomes.
RECENT FINDINGS: Maternal nutritional status, diet and exposure to environmental factors are increasingly acknowledged as potential factors affecting fetal growth both by altering nutrient availability to the fetus and by modulating placental gene expression, thus modifying placental function.
SUMMARY: Assessing nutritional and environmental factors associated with IUGR, and the molecular mechanisms by which they may have a role in the disease onset, is necessary to provide comprehensive and common guidelines for maternal care and recommended behaviours. Moreover, maternal genetic predispositions and early serum markers may allow a better and more specific monitoring of high risk pregnancies, optimizing the timing of delivery
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