1,720,974 research outputs found
Prenatal particulate matter exposure is linked with neurobehavioral development in early life
No full textPrenatal particulate matter exposure is linked with neurobehavioral development in early life
No full textPrenatal particulate matter exposure is linked with neurobehavioral development in early life
No full textPrenatal particulate matter exposure is linked with neurobehavioral development in early life
No full textImpact on murine neurodevelopment of early-life exposure to airborne ultrafine carbon nanoparticles
No full textThe effects of ultrafine particle (UFP) inhalation on neurodevelopment, especially during critical windows of early life, remain largely unexplored. The specific time windows during which exposure to UFP might be the most detrimental remain poorly understood. Here, we studied early-life exposure to clean ultrafine carbonaceous particles (UFPC) and neurodevelopment and central nervous system function in offspring.Pregnant wild-type C57BL/6J mice were either sham-exposed (HEPA-filtered air) or exposed to clean ultrafine carbonaceous particles at a concentration of 438 ± 72 μg/m³ (mean ± SD) and a count median diameter of 49 ± 2 nm (CMD ± GSD) via whole-body exposure for four hours per day. For prenatal exposure, mice were exposed for two consecutive days in two exposure periods, while the postnatal exposure was conducted for four consecutive days in two exposure periods. The mice were divided into four groups: (i) sham, (ii) only prenatal exposure, (iii) only postnatal exposure, and (iv) both prenatal and postnatal exposure. Neurodevelopmental behaviour was assessed throughout the life of the offspring using a functional observation battery.Early-life UFPC-exposed offspring exhibited altered anxiety-related behaviour in the open field test, with exclusively postnatally exposed offspring (567 ± 120 s) spending significantly more time within the border zone of the arena compared to the sham group (402 ± 73 s), corresponding to an increase of approximately 41% (p < 0.05). The behavioural alterations remained unaffected by olfactory function or maternal behaviour. Mice with both prenatal and postnatal exposure did not show this effect. No discernible impact on developmental behavioural reflexes was evident.Early life exposure to UFPC, particularly during the early postnatal period, may lead to developmental neurotoxicity, potentially resulting in complications for the central nervous system later in life. The current data will support future studies investigating the possible effects and characteristics of nanoparticle-based toxicity.Funding
This work was funded by the Flemish Scientific Research Foundation (FWO; G059219) and supported by the European Union’s Horizon 2020 research and innovation programme under grant agreement No 814978 (TUBE).
Acknowledgements
We would like to thank the National Institute for Public Health and the Environment (RIVM) technical staff for their significant contributions to this study. We express our special gratitude to Evert Duistermaat, Paul Fokkens,
and John Boere for their dedicated efforts in setting up the exposure experiments to ultrafine particles (UFPC). Their meticulous work in carrying out the exposures and processing the subsequent exposure data was crucial
to this study’s accomplishment. Without their expertise, this study would not have been possible. This work was funded by the Flemish Scientific Research Foundation (FWO; G059219) and supported by the European Union’s Horizon 2020 research and innovation programme under grant agreement No 814978 (TUBE)
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
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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