71 research outputs found
Biogeografía, ecología y etología de las liebres (Lepus callotis y Lepus californicus) en México
Biotecnologías de reproducción animal con posibilidad de aplicación para optimizar el potencial reproductivo y productivo de los animales. Una revisión
Animal reproductive biotechnology, represents an opportunity to optimize the potential reproductive and productive animals. The aim of this paper is a brief review of biotechnology in animal reproduction with future possibility of application to optimize thepotential reproductive and productive animals, such as in vitro fertilization, cloning and transgenesis.Las biotecnologías de reproducción animal, representan una oportunidad para optimizar el potencial reproductivo y productivo de los animales. El objetivo de este trabajo es presentar una breve revisión de las biotecnologías de reproducción animal con posibilidad futura de aplicación para optimizar el potencial reproductivo y productivo de los animales, tales como: fecundación in vitro, clonación y transgénesis
Estrés oxidativo y antioxidantes en la conservación espermática
El estrés oxidativo de los espermatozoides, se refiere al daño que pueden sufrir en la integridad de sus componentes estructurales y fisiológicos; cuyo efecto está directamente relacionado con la disminución de la sobrevivencia y capacidad fecundante después de ser eyaculados. El estrés oxidativo, es provocado por la formación de gran cantidad de especies reactivas al oxígeno (ROS) o moléculas que contienen radicales libres, las cuales se hacen presentes durante el manejo y manipulación del eyaculado, comprometiendo la viabilidad de los espermatozoides. La pérdida de la funcionalidad de los espermatozoides –capacidad fecundante- por la presencia de grandes cantidades de ROS, después de ser eyaculados, es motivo de gran interés y preocupación en el tema de la conservación seminal de machos reproductores, cuyo objetivo es mantener, mejorar y optimizar la eficiencia reproductiva en las Unidades de Producción Animal, en cualquier parte del mundo. En este trabajo se presenta una revisión sobre estrés oxidativo, antioxidantes, técnicas para valorar el estrés oxidativo en espermatozoides y al final un glosario de términos relacionados con el tema.Oxidative stress of spermatozoa, it refers to damage that may have on the integrity of their structural and physiological components, whose purpose is directly related to the decrease in the survival and fertilizing capacity after he ejaculates. Oxidative stress is caused by the formation of large amounts of reactive oxygen species (ROS), or molecules containing free radicals, which are present during the handling and manipulation of the ejaculate and jeopardize the viability of spermatozoa. The loss of the functionality of sperm-fertilizing capacity, the presence of large amounts of ROS, after he ejaculates, is of great interest and concern on the issue of preservation of seminal male breeding, which aims to maintain, improve and to optimize reproductive efficiency in animal production units, anywhere in the world. This paper presents an overview on oxidative stress, antioxidants, techniques for assessing oxidative stress in spermatozoa and in the end a glossary of terms related to the topic
Actores de la cadena productiva que deben participar para prevenir el uso de clembuterol en la engorda del ganado bovino en México
El clembuterol, Químicamente se describe como polvo blanco, anhidro, muy soluble en agua y altamente estable a temperatura ambiente, su punto de fusión es de 174 a 175.5 ºC. También es un derivado sintético perteneciente a una clase de medicamentos análogos fisiológicamente a la adrenalina, tiene la capacidad de interactuar con receptores adrenérgicos, generalmente del tipo ß2 (β agonista), es uno de los modificadores metabólicos más conocido en el área de producción de carne, debido al alto grado residual que deja esta sustancia en los tejidos comestibles y sus posibles repercusiones en la salud pública. En este trabajo, se describen los principales actores de la cadena productiva en la engorda de ganado que deben participar para prevenir el uso de clembuterol. La información fue recopilada de información científicas y publicaciones de las autoridades competentes, tales como: SENASICA, SAGARPA, COFEPRIS y Ley Federal de Sanidad Animal
Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world
Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic.
Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality.
Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States.
Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis.
Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection
Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector
A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements
The Changing Landscape for Stroke\ua0Prevention in AF: Findings From the GLORIA-AF Registry Phase 2
Background GLORIA-AF (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients with Atrial Fibrillation) is a prospective, global registry program describing antithrombotic treatment patterns in patients with newly diagnosed nonvalvular atrial fibrillation at risk of stroke. Phase 2 began when dabigatran, the first non\u2013vitamin K antagonist oral anticoagulant (NOAC), became available. Objectives This study sought to describe phase 2 baseline data and compare these with the pre-NOAC era collected during phase 1. Methods During phase 2, 15,641 consenting patients were enrolled (November 2011 to December 2014); 15,092 were eligible. This pre-specified cross-sectional analysis describes eligible patients\u2019 baseline characteristics. Atrial fibrillation disease characteristics, medical outcomes, and concomitant diseases and medications were collected. Data were analyzed using descriptive statistics. Results Of the total patients, 45.5% were female; median age was 71 (interquartile range: 64, 78) years. Patients were from Europe (47.1%), North America (22.5%), Asia (20.3%), Latin America (6.0%), and the Middle East/Africa (4.0%). Most had high stroke risk (CHA2DS2-VASc [Congestive heart failure, Hypertension, Age 6575 years, Diabetes mellitus, previous Stroke, Vascular disease, Age 65 to 74 years, Sex category] score 652; 86.1%); 13.9% had moderate risk (CHA2DS2-VASc = 1). Overall, 79.9% received oral anticoagulants, of whom 47.6% received NOAC and 32.3% vitamin K antagonists (VKA); 12.1% received antiplatelet agents; 7.8% received no antithrombotic treatment. For comparison, the proportion of phase 1 patients (of N = 1,063 all eligible) prescribed VKA was 32.8%, acetylsalicylic acid 41.7%, and no therapy 20.2%. In Europe in phase 2, treatment with NOAC was more common than VKA (52.3% and 37.8%, respectively); 6.0% of patients received antiplatelet treatment; and 3.8% received no antithrombotic treatment. In North America, 52.1%, 26.2%, and 14.0% of patients received NOAC, VKA, and antiplatelet drugs, respectively; 7.5% received no antithrombotic treatment. NOAC use was less common in Asia (27.7%), where 27.5% of patients received VKA, 25.0% antiplatelet drugs, and 19.8% no antithrombotic treatment. Conclusions The baseline data from GLORIA-AF phase 2 demonstrate that in newly diagnosed nonvalvular atrial fibrillation patients, NOAC have been highly adopted into practice, becoming more frequently prescribed than VKA in Europe and North America. Worldwide, however, a large proportion of patients remain undertreated, particularly in Asia and North America. (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients With Atrial Fibrillation [GLORIA-AF]; NCT01468701
Large expert-curated database for benchmarking document similarity detection in biomedical literature search
Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe
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