538 research outputs found
Coauthorship and Thematic Networks in AAEP Annual Meetings
We analyze the coauthorship production of the AAEP Annual Meeting since 1964.
We use social network analysis for creating coauthorship networks and given
that any paper must be tagged with two JEL codes, we use this information for
also structuring a thematic network. Then we calculate network metrics and find
main actors and clusters for coauthors and topics. We distinguish a gender gap
in the sample. Thematic networks show a cluster of codes and the analysis of
the cluster shows the preeminence of the tags related to trade, econometric,
distribution/poverty and health and education topics.Comment: 30 pages, 12 Figures, 16 Table
TaxonomÃa de la red de la élite capitular de Buenos Aires, 1776-1810
We analyze structural properties and visualization of a historical-data-constructed social network of the families with members in the Cabildo (city council) of colonial Buenos Aires. The data was obtained through the review of birth, marriage, and death records kept in various institutions and expanded from online genealogical sources. We find structural properties and visual presentations and also a link centrality analysis that shows that ritual relationship represents an important glue that held together with the network.Analizamos las propiedades estructurales y la visualización de una red social construida por datos históricos de las familias con miembros en el Cabildo (ayuntamiento) de la Buenos Aires colonial. Los datos se obtuvieron a través de la revisión de registros de nacimientos, matrimonios y defunciones mantenidos en varias instituciones y ampliados de fuentes genealógicas en lÃnea. Encontramos propiedades estructurales y presentaciones visuales y también un análisis de centralidad de enlace que muestra que las relaciones rituales representan un pegamento importante que mantuvo unida la red
Non cooperative stackelberg network formation.
Non-cooperative network formation games in industrial organizations analyzehow firms create links. We assume that links portray cost-reducing informationand that access to this information is not reciprocal. We study the consequences interms of profits if one firm can move first in establishing a link. A classic modelof exogenous Stackelberg leadership is developed and first-mover advantage isobserved.Non-cooperative network formation games in industrial organizations analyzehow firms create links. We assume that links portray cost-reducing informationand that access to this information is not reciprocal. We study the consequences interms of profits if one firm can move first in establishing a link. A classic modelof exogenous Stackelberg leadership is developed and first-mover advantage isobserved
Directions of high cycle fatigue cracks emanating from circular notches studied by optical profilometry
Current models for predicting the fatigue endurance of notched solids use the stresses along a straight line, beginning at the notch root, as a simplification of the real crack propagation path. In this work, the experimental crack paths for hollow notched samples were analysed through different microscopy techniques, with the objective of establishing high cycle fatigue crack growth directions in a mild steel. Fully reversed tension–compression fatigue tests
of thin-walled tube specimens with a passing-through hole were carried out. The crack paths observed in the outer cylindrical surface were studied in each case, with special attention to the crack initiation point and the crack direction along the first grains. Moreover, the analysis of the fracture surfaces allowed the same analysis to be performed to determine the internal crack paths. It was observed that the crack initiation point was close to the maximum principal stress point at the hole contour as obtained from linear elastic finite element analysis, and the crack direction in its initiation was generally close to Mode I direction, contrary to the conventionally accepted 45
crack growth direction.The authors would like to thank the European Union, the Spanish
Government and the Junta de AndalucÃa for its financial support through
grantsDPI2017-84788-PandPID2020-117407GB-I00(FEDER/Ministerio
de Ciencia e Innovación - Agencia Estatal de Investigación) and P18-FR-
4306 (‘‘Fondo Europeo de Desarrollo Regional (FEDER) y ConsejerÃa de
EconomÃa, Conocimiento, Empresas y Universidad de la Junta de AndalucÃa,
dentro del Programa Operativo FEDER 2014-2020’’). N.O. Larrosa
would also like to thank the UK Engineering and Physical Sciences
Research Council (EPSRC) for its financial support through grant number
EP/S012362/1
Pesticide exposure and gender discrepancy in breast cancer
OBJECTIVE: It is biologically plausible that occupational and environmental pesticide exposure may contribute to breast cancer risk. Persistent chemical compounds, such as pesticides, tend to be lipophilic and are detected in human breast milk and adipose tissue. Therefore, the present systematic review ims to clarify the gender difference in breast cancer concerning pesticide exposure.MATERIALS AND METHODS: A total of 70 studies satisfied the inclusion criteria and were included in the systematic review. RESULTS: From the studies analyzed, it was observed that exposure to pesticides could be a risk factor for breast cancer in women, in particular in young women and in women who experienced menarche at a young age. In contrast, no association was found for breast cancer in men. Female breast cancer is correlated with estrogen receptor-negative tumor characteristics. Breast cancer in men was no correlated with pesticide exposure. CONCLUSIONS: Breast cancer in women has been linked to estrogen receptor positivity, but this positivity appears to be inversely related to fertility. The estrogen-like effects of organochlorine
pesticides could be the cause of the observed gender differences
Different Psychophysiological Responses to a High-intensity Repetition Session Performed Alone or in a Group by Elite Middle-distance Runners
Internal training load refers to the degree of disturbance in psychophysiological homeostasis provoked by a training session and has been traditionally measured through session-RPE, which is the product of the session Rate of Perceived Exertion (RPE) and the duration. External training load refers to the actual physical work completed, and depends on session volume, intensity, frequency and density. Drafting, which is achieved
by running closely behind another runner has been demonstrated to reduce the energy cost of running at a fixed speed and to improve performance. Therefore, it is hypothesized that psychophysiological responses might reflect different levels of internal load if training is performed individually or collectively. 16 elite middle-distance runners performed two high-intensity training sessions consisting of 4 repetitions of 500 m separated by 3 minutes of active recovery. Sessions were performed individually and collectively. Times for each repetition, RPE, core affect (valence and felt arousal) and blood lactate concentrations [BLa] were measured after each repetition. Main time effect was significant and increased across repetitions for [BLa] and RPE (p <0.001), and decreased for valence (p =0.001). Main group effect was significant and values were higher when training individually for [BLa] (p =0.003) and RPE (p =0.001), and lower for valence (p =0.001). No differential responses were found between conditions in terms of repeat time or felt arousal. Findings demonstrate that elite middle-distance athletes
running collectively display lower levels of internal training load compared to running alone, despite external training load being similar
Accelerated Aging Experiments for Prognostics of Damage Growth in Composite Materials
Composite structures are gaining importance for use in the aerospace industry. Compared to metallic structures their behavior is less well understood. This lack of understanding may pose constraints on their use. One possible way to deal with some of the risks associated with potential failure is to perform in-situ monitoring to detect precursors of failures. Prognostic algorithms can be used to predict impending failures. They require large amounts of training data to build and tune damage model for making useful predictions. One of the key aspects is to get confirmatory feedback from data as damage progresses. These kinds of data are rarely available from actual systems. The next possible resource to collect such data is an accelerated aging platform. To that end this paper describes a fatigue cycling experiment with the goal to stress carbon-carbon composite coupons with various layups. Piezoelectric disc sensors were used to periodically interrogate the system. Analysis showed distinct differences in the signatures of growing failures between data collected at conditions. Periodic X-radiographs were taken to assess the damage ground truth. Results after signal processing showed clear trends of damage growth that were correlated to damage assessed from the X-ray images
Clinical Comparison of the Performance of Two Marketed Ophthalmic Viscoelastic Devices (OVDs): The Bacterially Derived Healon PRO OVD and Animal-Derived Healon OVD
This clinical investigation compared the clinical performance of two marketed ophthalmic viscoelastic devices (OVDs): the bacterially derived Healon PRO OVD (test) and the animal-derived Healon OVD (control) under normal use conditions during cataract removal and lens implantation. This prospective, multicenter, randomized, parallel, participant/evaluator masked, postmarket investigation enrolled 139 subjects (170 eyes), 116 (143 eyes) of which were treated (73 test; 70 control group). Both test and control OVDs were used, at a minimum, to inflate the anterior chamber and protect the endothelium prior to cataract extraction according to the standard procedure. The surgeon completed a postsurgery OVD clinical performance questionnaire, and intraocular pressure (IOP) was measured before surgery and at the 1 day postoperative visit with Goldmann applanation tonometry. Any IOP measurement of 30 mmHg or higher was considered a "spike"and recorded as a study-specific, serious adverse event. The bacterially derived Healon PRO OVD was found to be statistically noninferior to the overall clinical performance of the animal-derived Healon OVD control; thus, the primary hypothesis was satisfied. There were no statistically significant differences between OVD groups for any of the additional endpoints relating to IOP changes or to safety, thus satisfying additional hypotheses. The Healon PRO OVD showed statistically significant improvements in surgeon ratings for ease of injectability, transparency/visibility, and ease of IOL placement. The safety profile was also similar between OVD groups with regards to serious and/or device-related adverse events, as well as medical and lens findings. The results of this clinical investigation support the safety and effectiveness of the bacterially derived, currently marketed Healon PRO OVD and indicate that the intraocular surgical performance was similar between the two OVDs
Ru-Catalyzed C-H Arylation of Fluoroarenes with Aryl Halides
We gratefully acknowledge the Engineering and Physical
Sciences Research Council (EPSRC, EP/I038578/1 and EP/
K039547/1) for funding and the European Research Council
for a Starting Grant (to I.L.).
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