Universidad del Norte, Colombia

About: Universidad del Norte, Colombia is a education organization based out in Barranquilla, Colombia. It is known for research contribution in the topics: Population & Context (language use). The organization has 3562 authors who have published 4355 publications receiving 37861 citations. The organization is also known as: University of the North, Colombia & Uninorte.

Practical global salinity gradient energy potential

Abstract: Salinity gradient energy (SGE) is a clean and renewable energy source that can be harnessed from the controlled mixing of two water masses of different salt concentration. Various natural and artificial systems offer conditions under which SGE can be harnessed amongst which river mouths play the prominent role in a global assessment. The theoretical SGE potential at river mouths has been previously estimated to be 15,102 TWh/a, equivalent to 74% of the worldwide electricity consumption; however, practical extractable SGE from these systems depends on several physical and environmental constraints that are discussed here. The suitability, sustainability and reliability of the exploitation of this renewable energy are considered based on quantified descriptors. It is shown that practically 625 TWh/a of SGE are globally extractable from river mouths, equivalent to 3% of global electricity consumption. Although this is much smaller than the theoretical potential, is still a significant amount of clean energy.

Respiratory syncytial virus NS1 protein colocalizes with mitochondrial antiviral signaling protein MAVS following infection.

Abstract: Respiratory syncytial virus (RSV) nonstructural protein 1(NS1) attenuates type-I interferon (IFN) production during RSV infection; however the precise role of RSV NS1 protein in orchestrating the early host-virus interaction during infection is poorly understood. Since NS1 constitutes the first RSV gene transcribed and the production of IFN depends upon RLR (RIG-I-like receptor) signaling, we reasoned that NS1 may interfere with this signaling. Herein, we report that NS1 is localized to mitochondria and binds to mitochondrial antiviral signaling protein (MAVS). Live-cell imaging of rgRSV-infected A549 human epithelial cells showed that RSV replication and transcription occurs in proximity to mitochondria. NS1 localization to mitochondria was directly visualized by confocal microscopy using a cell-permeable chemical probe for His(6)-NS1. Further, NS1 colocalization with MAVS in A549 cells infected with RSV was shown by confocal laser microscopy and immuno-electron microscopy. NS1 protein is present in the mitochondrial fraction and co-immunoprecipitates with MAVS in total cell lysatesof A549 cells transfected with the plasmid pNS1-Flag. By immunoprecipitation with anti-RIG-I antibody, RSV NS1 was shown to associate with MAVS at an early stage of RSV infection, and to disrupt MAVS interaction with RIG-I (retinoic acid inducible gene) and the downstream IFN antiviral and inflammatory response. Together, these results demonstrate that NS1 binds to MAVS and that this binding inhibits the MAVS-RIG-I interaction required for IFN production.

Quantum gravity effects in the Kerr spacetime

Abstract: We analyze the impact of the leading quantum gravity effects on the properties of black holes with nonzero angular momentum by performing a suitable renormalization group improvement of the classical Kerr metric within quantum Einstein gravity. In particular, we explore the structure of the horizons, the ergosphere, and the static limit surfaces as well as the phase space available for the Penrose process. The positivity properties of the effective vacuum energy-momentum tensor are also discussed and the ``dressing'' of the black hole's mass and angular momentum are investigated by computing the corresponding Komar integrals. The pertinent Smarr formula turns out to retain its classical form. As for their thermodynamical properties, a modified first law of black-hole thermodynamics is found to be satisfied by the improved black holes (to second order in the angular momentum); the corresponding Bekenstein-Hawking temperature is not proportional to the surface gravity.

Asthma and other allergic conditions in Colombia: a study in 6 cities

Abstract: Background No detailed information is available on the burden and impact of allergic diseases simultaneously for adults and children in Colombia and most Latin American countries. Objectives To investigate the prevalence of asthma, allergic rhinitis, and atopic dermatitis symptoms in 6 cities in Colombia; to measure patient expenses and school days and workdays lost; to describe disease severity; and to determine levels of total and specific IgE in asthmatic subjects. Methods A multistage stratified random sample selection of schools with subjects aged 5 to 18 years in each city was used. Guardian subjects selected were contacted, and home visits were arranged. Subjects aged 1 to 4 years and older than 19 years were also selected randomly by systematic sampling based on the addresses of the subjects aged 5 to 18 years. Subjects with asthma symptoms were invited to provide a blood sample. Results Information was obtained from 6,507 subjects. The prevalence of asthma, rhinitis, and atopic dermatitis symptoms in the past 12 months was 10.4% (95% confidence interval [CI], 9.7%–11.1%), 22.6% (95% CI, 21.6%–23.6%), and 3.9% (95% CI, 3.4%–4.4%), respectively. Thirty-eight percent of asthmatic subjects had visited the emergency department or have been hospitalized, and 50% reported lost school days and workdays. Seventy-six percent of sampled asthmatic patients were considered to be atopic. Conclusions The burden of disease and societal consequences of allergic entities in urban settings in countries such as Colombia are of concern but are largely ignored, perhaps because of the misconception that these diseases are of public health importance only in industrialized nations.