219 research outputs found

    W196 and the ß -Hairpin Motif Modulate the Redox Switch of Conformation and the Biomolecular Interaction Network of the Apoptosis-Inducing Factor

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    The human apoptosis-inducing factor (hAIF) is a moonlight flavoprotein involved in mitochondrial respiratory complex assembly and caspase-independent programmed cell death. These functions might be modulated by its redox-linked structural transition that enables hAIF to act as a NAD(H/+) redox sensor. Upon reduction with NADH, hAIF undergoes a conformational reorganization in two specific insertions - the flexible regulatory C-loop and the 190-202 ß-harpin - promoting protein dimerization and the stabilization of a long-life charge transfer complex (CTC) that modulates its monomer-dimer equilibrium and its protein interaction network in healthy mitochondria. In this regard, here, we investigated the precise function of the ß-hairpin in the AIF conformation landscape related to its redox mechanism, by analyzing the role played by W196, a key residue in the interaction of this motif with the regulatory C-loop. Mutations at W196 decrease the compactness and stability of the oxidized hAIF, indicating that the ß-hairpin and C-loop coupling contribute to protein stability. Kinetic studies complemented with computational simulations reveal that W196 and the ß-hairpin conformation modulate the low efficiency of hAIF as NADH oxidoreductase, contributing to configure its active site in a noncompetent geometry for hydride transfer and to stabilize the CTC state by enhancing the affinity for NAD+. Finally, the ß-hairpin motif contributes to define the conformation of AIF's interaction surfaces with its physiological partners. These findings improve our understanding on the molecular basis of hAIF''s cellular activities, a crucial aspect for clarifying its associated pathological mechanisms and developing new molecular therapies

    Infección por SARS-CoV-2 y la lactancia materna en las gestantes. Trujillo, 2020-2021

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    SARS-CoV-2 is a respiratory syndrome that affects the entire population. This report focuses on pregnant women infected with SARS-CoV-2 and the relationship with breastfeeding. The general objective is to determine the relationship between SARS-COV-2 infection and breastfeeding in pregnant women. For this, it was possible to collect data from the Control Notebook of a hospital to 99 female patients with possible infection to SARS-CoV-2 in Trujillo, which were collected in the period from November 16, 2020 to April 04, 2021, by means of a census sampling. These data were collected by the Observation technique and two instruments were made called: SARS-COV-2 Observation Guide and Breastfeeding Observation Guide. Then contingency tables were elaborated and some statistical measures were calculated to describe the data set, for which the Microsoft Excel program was used. Finally, in the general objective in the results, it was possible to estimate with a significance value that was P = 0.7005> 0.05, which accepts the null hypothesis. In conclusion, SARS-CoV-2 infection is not significantly related to breastfeeding in pregnant women, Trujillo, 2020-2021.El SARS-CoV-2 es un síndrome respiratorio que afecta a toda la población. Este informe se centra en las mujeres embarazadas que están infectadas por SARS-CoV-2 y la relación con la lactancia materna. Esta presente investigación sostuvo como objetivo general determinar la relación entre la infección por SARS-COV-2 y la lactancia materna en mujeres gestantes. Para ello se logró hacer la recolección de datos del Cuaderno de control de un hospital a 99 pacientes femeninas con posible infección a SARS-CoV-2 en Trujillo, lo cual fueron recolectadas en el periodo del 16 de noviembre del 2020 a 04 abril del 2021, mediante un muestreo censal. Estos datos fueron recogidos por la técnica de Observación y se logró hacer dos instrumentos llamados: Guía de observación de SARS-COV-2 y Guía de observación de Lactancia Materna. Luego se elaboraron tablas de contingencia y se calcularon algunas medidas estadísticas para describir el conjunto de datos, para lo cual se empleó la herramienta Microsoft Excel. Finalmente, en el objetivo general en los resultados realizados se logró estimar con un valor de significancia fue P=   0.7005 >    0.05, lo cual se acepta la hipótesis nula. En conclusión, la Infección por SARS-CoV-2 no se relaciona significativamente con la lactancia materna en las gestantes, Trujillo, 2020-2021

    Comparison of constant load exercise intensity for verification of maximal oxygen uptake following a graded exercise test in older adults

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    Maximal oxygen uptake (VO2max) declines with advancing age and is a predictor of morbidity and mortality risk. The purpose here was to assess the utility of constant load tests performed either above or below peak work rate obtained from a graded exercise test for verification of VO2max in older adults. Twenty-two healthy older adults (9M, 13F, 67 ± 6 years, BMI: 26.3 ± 5.1 kg·m−2) participated in the study. Participants were asked to complete two experimental trials in a randomized, counterbalanced cross-over design. Both trials (cycle ergometer) consisted of (1) an identical graded exercise test (ramp) and (2) a constant load test at either 85% (CL85; n = 22) or 110% (CL110; n = 20) of the peak work rate achieved during the associated ramp (performed 10-min post ramp). No significant differences were observed for peak VO2 (L·min−1) between CL85 (1.86 ± 0.72; p = 0.679) or CL110 (1.79 ± 0.73; p = 0.200) and the associated ramp (Ramp85, 1.85 ± 0.73; Ramp110, 1.85 ± 0.57). Using the study participant\u27s mean coefficient of variation in peak VO2 between the two identical ramp tests (2.9%) to compare individual differences between constant load tests and the associated ramp revealed 19/22 (86%) of participants achieved a peak VO2 during CL85 that was similar or higher versus the ramp, while only 13/20 (65%) of participants achieved a peak VO2 during CL110 that was similar or higher versus the ramp. These data indicate that if a verification of VO2max is warranted when testing older adults, a constant load effort at 85% of ramp peak power may be more likely to verify VO2max as compared to an effort at 110% of ramp peak power

    Fluctuación poblacional de ototylomys phyllotis merriam, 1901 (rodentia: muridae) en una selva mediana subcaducifolia del Sur de Yucatán, México

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    Population dinamics of the big-eared climbing rat (Ototylomys phyllotis) was studied in a subdeciduous tropical rainforest located at Rancho Hobonil, Tzucacab, Yucatan using a mark-recapturetechnique, from April 1996 to April 1998 during five nights per 24 months. The minimum-numberknown-alive technique (MNKA) was used to estimate population size. We captured 123 rats, 52% werefemales and 48% males. The sex ratio was 1:1 during this study. Density ranged from 10 to 46 ind./ha. And was not significantly correlated with precipitation (p>0.05). Presence of reproductive individuals from both sexes during the majorities of the studied months and the reproductive activity from females suggest a continuous poliestric pattern for this species.Se estudió la dinámica poblacional de la rata arborícola Ototylomys phyllotis en la selva mediana subcaducifolia del Rancho Hobonil, Tzucacab, Yucatán. Se trabajó de abril de 1996 a abril de 1998, usando el método de captura recaptura y trampeando por cinco noches consecutivas cada mes. La densidad se estimó mediante el método de Número Mínimo de Individuos Vivos (NMIV). Se capturaron un total de 123 individuos, de los cuales el 49% fueron hembras y el 51% machos. La proporción de sexos se mantuvo 1:1. La densidad poblacional fluctuó entre 10 y 46 individuos/ha. No se presentó correlación significativa entre la densidad y la precipitación pluvial anual (p<0.05). Los adultosconstituyeron el principal componente de la población. La presencia de reproductores de ambos sexos, así como la actividad reproductiva de las hembras durante la mayoría de los meses de estudio, sugiereque esta especie presenta un patrón reproductivo poliéstrico continuo

    Neonatal infrared thermography images in the hypothermic ruminant model: Anatomical-morphological-physiological aspects and mechanisms for thermoregulation

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    Hypothermia is one factor associated with mortality in newborn ruminants due to the drastic temperature change upon exposure to the extrauterine environment in the first hours after birth. Ruminants are precocial whose mechanisms for generating heat or preventing heat loss involve genetic characteristics, the degree of neurodevelopment at birth and environmental aspects. These elements combine to form a more efficient mechanism than those found in altricial species. Although the degree of neurodevelopment is an important advantage for these species, their greater mobility helps them to search for the udder and consume colostrum after birth. However, anatomical differences such as the distribution of adipose tissue or the presence of type II muscle fibers could lead to the understanding that these species use their energy resources more efficiently for heat production. The introduction of unconventional ruminant species, such as the water buffalo, has led to rethinking other characteristics like the skin thickness or the coat type that could intervene in the thermoregulation capacity of the newborn. Implementing tools to analyze species-specific characteristics that help prevent a critical decline in temperature is deemed a fundamental strategy for avoiding the adverse effects of a compromised thermoregulatory function. Although thermography is a non-invasive method to assess superficial temperature in several non-human animal species, in newborn ruminants there is limited information about its application, making it necessary to discuss the usefulness of this tool. This review aims to analyze the effects of hypothermia in newborn ruminants, their thermoregulation mechanisms that compensate for this condition, and the application of infrared thermography (IRT) to identify cases with hypothermia

    “Publishing Is Mystical”: The Latinx Caucus Bibliography, Top-Tier Journals, and Minority Scholarship

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    In 2014, members of the NCTE/CCCC Latinx Caucus began contributing citations to a shared Google Document (GDoc) that suggested a relatively significant contribution of scholarship to the field of Rhetoric and Composition studies. Scholars of color have argued that rhetoric and composition scholarship fails to represent diversity in academic publications (Baca; Banks; Jones Royster; Pimentel; Ruíz). This study examines statistical data arrived at through analysis of the NCTE/CCCC Latinx Caucus Bibliography, with survey and interview data from Latinx scholars providing important context about publishing for people of color

    Analyzing multitarget activity landscapes using protein-ligand interaction fingerprints: interaction cliffs.

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    This is the original submitted version, before peer review. The final peer-reviewed version is available from ACS at http://pubs.acs.org/doi/abs/10.1021/ci500721x.Activity landscape modeling is mostly a descriptive technique that allows rationalizing continuous and discontinuous SARs. Nevertheless, the interpretation of some landscape features, especially of activity cliffs, is not straightforward. As the nature of activity cliffs depends on the ligand and the target, information regarding both should be included in the analysis. A specific way to include this information is using protein-ligand interaction fingerprints (IFPs). In this paper we report the activity landscape modeling of 507 ligand-kinase complexes (from the KLIFS database) including IFP, which facilitates the analysis and interpretation of activity cliffs. Here we introduce the structure-activity-interaction similarity (SAIS) maps that incorporate information on ligand-target contact similarity. We also introduce the concept of interaction cliffs defined as ligand-target complexes with high structural and interaction similarity but have a large potency difference of the ligands. Moreover, the information retrieved regarding the specific interaction allowed the identification of activity cliff hot spots, which help to rationalize activity cliffs from the target point of view. In general, the information provided by IFPs provides a structure-based understanding of some activity landscape features. This paper shows examples of analyses that can be carried out when IFPs are added to the activity landscape model.M-L is very grateful to CONACyT (No. 217442/312933) and the Cambridge Overseas Trust for funding. AB thanks Unilever for funding and the European Research Council for a Starting Grant (ERC-2013- StG-336159 MIXTURE). J.L.M-F. is grateful to the School of Chemistry, Department of Pharmacy of the National Autonomous University of Mexico (UNAM) for support. This work was supported by a scholarship from the Secretariat of Public Education and the Mexican government

    Near-infrared photometry and spectroscopy of the low Galactic latitude globular cluster 2MASS-GC03

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    We present deep near-infrared photometry and spectroscopy of the globular cluster 2MASS-GC03 projected in the Galactic disk using MMIRS on the Clay telescope (Las Campanas Observatory) and VISTA Variables in the Via Lactea survey (VVV) data. Most probable cluster member candidates were identified from near-infrared photometry. Out of ten candidates that were followed-up spectroscopically, five have properties of cluster members, from which we calculate = -0.9 +/- 0.2 and a radial velocity of v_r > = -78 +- 12km/s. A distance of 10.8kpc is estimated from 3 likely RRLyrae members. Given that the cluster is currently at a distance of 4.2kpc from the Galactic center, the cluster's long survival time of an estimated 11.3 +/- 1.2 Gyr strengthens the case for its globular-cluster nature. The cluster has a hint of elongation in the direction of the Galactic center.Peer reviewedFinal Published versio
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