Instituto Politécnico Nacional

About: Instituto Politécnico Nacional is a education organization based out in Mexico City, Mexico. It is known for research contribution in the topics: Population & Context (language use). The organization has 43351 authors who have published 63315 publications receiving 938532 citations. The organization is also known as: Instituto Politécnico Nacional & Instituto Politecnico Nacional.

Using Isoscapes to Trace the Movements and Foraging Behavior of Top Predators in Oceanic Ecosystems

Abstract: The stable isotope composition of animal tissues can provide intrinsic tags to study the foraging and migratory ecology of predators in the open ocean. Chapter 13 (this volume) demonstrated that by comparing the isotope values of an animal and its local prey or environment, the animal’s movements can be estimated, given that isotopic variation exists between habitats. The utility of using geographical variations in stable isotopes values, or isoscapes to study the movements of marine predators has been limited because of our lack of knowledge on the spatial variation of the carbon, nitrogen, and oxygen isotope values in the open ocean.

The chandra cosmos legacy survey: overview and point source catalog

Abstract: The COSMOS-Legacy survey is a 4.6 Ms Chandra program that has imaged 2.2 deg2 of the COSMOS field with an effective exposure of ≃ 160 ks over the central 1.5 deg^2 and of ≃ 80 ks in the remaining area. The survey is the combination of 56 new observations obtained as an X-ray Visionary Project with the previous C-COSMOS survey. We describe the reduction and analysis of the new observations and the properties of 2273 point sources detected above a spurious probability of 2 × 10^(−5). We also present the updated properties of the C-COSMOS sources detected in the new data. The whole survey includes 4016 point sources (3814, 2920 and 2440 in the full, soft, and hard band). The limiting depths are 2.2 × 10^(−16), 1.5 × 10^(−15), and 8.9 × 10^(−16) erg cm^(-2)s^(-1) in the 0.5–2, 2–10, and 0.5–10 keV bands, respectively. The observed fraction of obscured active galactic nuclei with a column density >10^(22) cm^(−2) from the hardness ratio (HR) is 50_(-16)^(+17)%. Given the large sample we compute source number counts in the hard and soft bands, significantly reducing the uncertainties of 5%–10%. For the first time we compute number counts for obscured (HR > −0.2) and unobscured (HR < −0.2) sources and find significant differences between the two populations in the soft band. Due to the unprecedent large exposure, COSMOS-Legacy area is three times larger than surveys at similar depths and its depth is three times fainter than surveys covering similar areas. The area-flux region occupied by COSMOS-Legacy is likely to remain unsurpassed for years to come.

Water Confined in Nanotubes and between Graphene Sheets: A First Principle Study

Abstract: Water confined at the nanoscale has been the focus of numerous experimental and theoretical investigations in recent years, yet there is no consensus on such basic properties as diffusion and the nature of hydrogen bonding (HB) under confinement. Unraveling these properties is important to understand fluid flow and transport at the nanoscale, and to shed light on the solvation of biomolecules. Here we report on a first principle, computational study focusing on water confined between prototypical nonpolar substrates, i.e., single-wall carbon nanotubes and graphene sheets, 1−2.5 nm apart. The results of our molecular dynamics simulations show the presence of a thin, interfacial liquid layer (∼5 A) whose microscopic structure and thickness are independent of the distance between confining layers. The properties of the HB network are very similar to those of the bulk outside the interfacial region, even in the case of strong confinement. Our findings indicate that the perturbation induced by the presence of ...

Berries: Improving Human Health and Healthy Aging, and Promoting Quality Life—A Review

Abstract: The importance of the diet in relation to human health has increased the interest of consumers on nutraceuticals rich foods, and especially on fruits and vegetables. Berries are rich sources of a wide variety of antioxidant phenolics; these phytochemicals include flavonoids, stilbenes, tannins, and phenolic acids. Reactive oxidant species and free radicals are produced in an extensive range of physiological processes. In addition to the antioxidant defenses produced in the body, there are exogenous sources supplied by the diet; this is the case of berry fruits, among others. The insufficiency of antioxidant defense mechanisms is associated to the pathology of chronic disorders such as cardiovascular diseases, inflammation, and diabetes. Therefore, the enforcement of the latter mechanisms is of the utmost importance. The isolation and characterization of compounds that may delay the onset of aging is receiving intense research attention; some berry phenolics are being associated with this functional performance. Berry phenolics may also act as antimicrobials which may be of help in the control of the wild spectra of pathogens, in view of recent problems associated with antibiotic resistance. Most of the research works on the antioxidant activity of bioactive constituents of berries has been carried out using in vitro assays. In view of this, the human studies investigating the bioavailability and potential toxicity of phenolics are receiving more attention. Finally, we would like to emphasize the necessity of associating new plant breeding and genetic studies of berries with the expression and overexpression of compounds for human health and healthy aging.

Neutrophil-to-lymphocyte ratio and lymphocyte-to-C-reactive protein ratio in patients with severe coronavirus disease 2019 (COVID-19): A meta-analysis.

Abstract: Since March 11, 2020, the World Health Organization (WHO) defined Coronavirus disease 2019 (COVID-19) as a pandemic, with a series of confirmed cases that currently exceeded 300,000 people worldwide and with approximately 14,500 deaths. Accumulated evidence suggests that a subgroup of patients with severe COVID-19 could have a dysregulation of the immune response that allows the development of viral hyperinflammation. Thus, all patients with severe COVID-19 should be screened for hyperinflammation using laboratory parameters in order to improve mortality. Neutrophil-to-Lymphocyte ratio (NLR) and Lymphocyte-to-C-reactive protein ratio (LCR) are established inflammation markers that reflect systemic inflammatory response, and both are available in almost all laboratories. In this study, a meta-analysis was performed to investigate whether NLR and LCR values can help predict clinical severity in patients with COVID-19. This article is protected by copyright. All rights reserved.