192 research outputs found

    Mechanisms underlying the association between breastfeeding and obesity

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    Decades of epidemiological research have established that breastfeeding is associated with a modest reduction in risk of later overweight and obesity. However, no systematic effort has been made to delineate the mechanisms that may explain this association. This review summarizes evidence from a variety of disciplines to understand the potential mechanisms underlying this association. One possibility is that this association is spurious and that confounding factors fully or partially explain this association. Additionally, breastfeeding could confer protection by: encouraging the infant\u27s emerging capabilities of self-regulation of intake; reducing problematic feeding behaviors on the part of caregivers that interfere with the infant\u27s self-regulation of intake; and providing bioactive factors that regulate energy intake, energy expenditure, and cellular chemistry. These three protective effects may promote slower growth and lower body fat levels in breastfed infants, which reduce risk of overweight and obesity later in life

    Opportunities for the Primary Prevention of Obesity during Infancy

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    Are chubby babies healthy babies? Whereas most seem well during infancy, evidence is increasing that heavier babies have a poorer long-term health trajectory than their trimmer counterparts. Data have emerged over the past 2 decades that early life growth patterns and behaviors play an important role in the etiology of obesity, yet there has been very little focus on the primary prevention of obesity during infancy by the medical, behavioral health, and public health communities. A recent report from the National Health and Nutrition Examination Survey (NHANES) highlighted the need for very early intervention when it revealed that between 2003 and 2006, a staggering 24.4% of children aged 2 to 5 years already were overweight or obese (body mass index [BMI; calculated as the weight in kilograms divided by height in meters squared] 85th–94th and ≥95th percentiles, respectively) [1]. NHANES data also have described obesity (weight-for-length/height ≥95th percentile) among infants younger than 2 years ( Fig. 1). Between the late 1970s and 2000, the prevalence of obesity among infants 6 to 23 months old increased by more than 60% [2]. Reports from the Centers for Disease Control and Prevention (CDC) Pediatric Nutrition Surveillance System [3] and a Massachusetts Health Maintenance Organization [4] similarly showed significant increases in the prevalence of overweight for infants and toddlers for all age groups since the 1980

    Geographical implications of seasonal reproduction in the bat star Asterina stellifera

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    The reproductive cycle and environmental cues that regulate gonad production in Asterina stellifera were studied from April 2009 to April 2011 in a rocky subtidal habitat at the southernmost limit of its distribution (Mar del Plata, Argentina). The geographic variation in reproductive traits between latitudinal range limits was analyzed. The gonadal and pyloric caeca weight varied with sea star size and time in both sexes. Despite a previous study suggested absence of recruitment in a 4 years period, our data of the same period demonstrated that spawning happens from early spring to early summer. The gonad and pyloric caeca weight did not show an inverse relationship, this suggested that there is no dependence on energy transfer between the organs and that the bat star presented a good nutritional state. Seawater temperature appears to be the variable explaining gonad proliferation at the range limits of A. stellifera distribution. Furthermore, differences in sex ratio, oocyte production, oogenesis duration and capability of energy transformation into ova were found between range limits.Fil: Meretta, Pablo Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Rubilar Panasiuk, Cynthia Tamara. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Cledón, Maximiliano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Ventura, C. Renato C.. Universidade Federal Do Rio de Janeiro. Museu Nacional; Brasi

    An updated view and perspectives on high-energy gamma-ray emission from SGR J1935+2154 and its environment

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    SGR J1935+2154 was discovered in 2016 and is currently one of the most burst-active Soft Gamma-ray Repeaters (SGR), having emitted several X-ray bursts in recent years. In one of our previous articles, we investigated the contribution to high-energy and very high-energy gamma-ray emission (VHE, E>100E > 100 GeV) due to cosmic-ray acceleration of SNR G57.2+0.8 hosting SGR J1935+2154 using the GALPROP propagation code. However, follow-up observations of SGR 1935+2154 were made for 2 hours on April 28, 2020, using the High Energy Stereoscopic System (H.E.S.S.). The observations coincide with X-ray bursts detected by INTEGRAL and Fermi/Gamma-ray Burst Monitor (GBM). These are the first high-energy gamma-ray observations of an SGR in a flaring state, and upper limits on sustained and transient emission have been derived. Now that new H.E.S.S. observations have been made, it is interesting to update our model with respect to these new upper limits. We extend our previous results to a more general situation using the new version of GALPROP. We obtain a hadronic model that confirms the results discussed by H.E.S.S.. This leads to an optimistic prospect that cosmic ray gamma rays from SGR J1935+2154 can contribute to the overall gamma energy density distribution and in particular to the diffusion gamma rays from the Galactic center.Comment: 9 Pages; 3 Figures. Comments are welcome. arXiv admin note: text overlap with arXiv:2106.0300

    Asignación del riesgo de diseño, financiamiento, construcción y fuerza mayor en la explotación y su impacto en la ejecución del contrato de concesión longitudinal de la Sierra-Tramo 2

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    El presente trabajo de investigación consiste en el estudio del contrato de Concesión de la Carretera Longitudinal de la Sierra-Tramo 2: Ciudad de Dios - Cajamarca-Chiple, Cajamarca-Trujillo y Dv. Chilete-Empalme PE-3N, que fue suscrito el 28 de mayo de 2013, entre el Estado peruano y Consorcio Consierra Tramo II, conformado por las empresas Sacyr Concesiones S.L. y Constructora Málaga Hnos. S.A., desde la estructuración hasta el desempeño de la concesión. La investigación se centra en un contrato del sector transportes, debido a que dicho sector ha sido habitual en concesiones y a que desde él se continuará impulsando proyectos de infraestructura vial. Por ello, este estudio considera la brecha que el Estado aún tiene que atender y su importancia para el desarrollo económico del país. Como parte de esta investigación, se han identificado los problemas ocurridos en las etapas por las cuales ha pasado el contrato desde su inició hasta la fecha de redacción del presente trabajo. De estos problemas, se han analizado aquellos que tienen relación con la demora en la ejecución del contrato, por lo que se ha determinado que estos ocurrieron en la asignación de los riesgos de diseño, construcción y explotación. Por tanto, las conclusiones y recomendaciones se orientan a mejoras para la fase de estructuración de la asociación público-privada en materia de asignación de riesgos

    The importance of environmental education in students: analyzing the transition from middle to high school in Nuevo Laredo, Tamaulipas, Mexico

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    A research was conducted with 246 first-semester high school students in Nuevo Laredo, Tamaulipas, Mexico with the aim of discovering if they had received extracurricular environmental education during middle school and how this training could influence their perceptions and positions towards environmental topics. Only 167 participants reported receiving extracurricular environmental education in middle school. The other 79 participants admitted not having done so. The same questionnaire with sentences on water culture, recycling, species care and transportation, as well as on the general knowledge of the environment and its regulations was applied to all the students. SPSS was used to categorize the two groups and perform nonparametric Mann-Whitney tests, which revealed that students who received additional environmental education in middle school showed a better attitude towards water care. To interpret our results, it is necessary to consider that the study was conducted only in the city of Nuevo Laredo, Tamaulipas and that a convenience sampling was used. Our findings also showed that there are still students who do not get enough environmental education. We conclude that it is important to intensify efforts to change this situation, since training on the environment has been shown to positively influence the attitudes of the students who received it.Objective: A poll on first-semester high school students (n = 246) took place at NuevoLaredo, Tamaulipas, Mexico, to find out if they received environmental education as anextracurricular class during middle school and how this training could influence theirperceptions and positions on environmental issues.Design/methodology/approach: A questionnaire that contained aspects regard waterculture, recycling, species care and transportation, as well as general knowledge of theenvironment and its regulations, was applied to students. The SPSS statistical software wasused to categorize two groups: students who received extracurricular environmentaleducation and those who did not. Subsequently, the non-parametric Mann Whitney testswere performed on the data.Results: Out of the total number of participants, 167 said they had received extracurricularenvironmental education in middle school. The other 79 participants reported not to havedone so. Students who received more environmental education in middle school exhibit abetter attitude regard water management. Limitations of the study/implications: To interpret the results, it is necessary to considerthat the study took place only in the city of Nuevo Laredo, Tamaulipas and that aconvenience sampling was used.Findings / Conclusions: There are still students that do not receive enough environmentaleducation. We conclude that it is important to intensify efforts to change this situation, asenvironmental training has shown to positively influence the attitudes of students whoreceived it

    Discovering Dysfunction of Multiple MicroRNAs Cooperation in Disease by a Conserved MicroRNA Co-Expression Network

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    MicroRNAs, a new class of key regulators of gene expression, have been shown to be involved in diverse biological processes and linked to many human diseases. To elucidate miRNA function from a global perspective, we constructed a conserved miRNA co-expression network by integrating multiple human and mouse miRNA expression data. We found that these conserved co-expressed miRNA pairs tend to reside in close genomic proximity, belong to common families, share common transcription factors, and regulate common biological processes by targeting common components of those processes based on miRNA targets and miRNA knockout/transfection expression data, suggesting their strong functional associations. We also identified several co-expressed miRNA sub-networks. Our analysis reveals that many miRNAs in the same sub-network are associated with the same diseases. By mapping known disease miRNAs to the network, we identified three cancer-related miRNA sub-networks. Functional analyses based on targets and miRNA knockout/transfection data consistently show that these sub-networks are significantly involved in cancer-related biological processes, such as apoptosis and cell cycle. Our results imply that multiple co-expressed miRNAs can cooperatively regulate a given biological process by targeting common components of that process, and the pathogenesis of disease may be associated with the abnormality of multiple functionally cooperative miRNAs rather than individual miRNAs. In addition, many of these co-expression relationships provide strong evidence for the involvement of new miRNAs in important biological processes, such as apoptosis, differentiation and cell cycle, indicating their potential disease links

    Doxorubicin-induced chronic dilated cardiomyopathy—the apoptosis hypothesis revisited

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    The chemotherapeutic agent doxorubicin (DOX) has significantly increased survival rates of pediatric and adult cancer patients. However, 10% of pediatric cancer survivors will 10–20 years later develop severe dilated cardiomyopathy (DCM), whereby the exact molecular mechanisms of disease progression after this long latency time remain puzzling. We here revisit the hypothesis that elevated apoptosis signaling or its increased likelihood after DOX exposure can lead to an impairment of cardiac function and cause a cardiac dilation. Based on recent literature evidence, we first argue why a dilated phenotype can occur when little apoptosis is detected. We then review findings suggesting that mature cardiomyocytes are protected against DOX-induced apoptosis downstream, but not upstream of mitochondrial outer membrane permeabilisation (MOMP). This lack of MOMP induction is proposed to alter the metabolic phenotype, induce hypertrophic remodeling, and lead to functional cardiac impairment even in the absence of cardiomyocyte apoptosis. We discuss findings that DOX exposure can lead to increased sensitivity to further cardiomyocyte apoptosis, which may cause a gradual loss in cardiomyocytes over time and a compensatory hypertrophic remodeling after treatment, potentially explaining the long lag time in disease onset. We finally note similarities between DOX-exposed cardiomyocytes and apoptosis-primed cancer cells and propose computational system biology as a tool to predict patient individual DOX doses. In conclusion, combining recent findings in rodent hearts and cardiomyocytes exposed to DOX with insights from apoptosis signal transduction allowed us to obtain a molecularly deeper insight in this delayed and still enigmatic pathology of DC

    Exploring Metabolic Pathway Reconstruction and Genome-Wide Expression Profiling in Lactobacillus reuteri to Define Functional Probiotic Features

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    The genomes of four Lactobacillus reuteri strains isolated from human breast milk and the gastrointestinal tract have been recently sequenced as part of the Human Microbiome Project. Preliminary genome comparisons suggested that these strains belong to two different clades, previously shown to differ with respect to antimicrobial production, biofilm formation, and immunomodulation. To explain possible mechanisms of survival in the host and probiosis, we completed a detailed genomic comparison of two breast milk–derived isolates representative of each group: an established probiotic strain (L. reuteri ATCC 55730) and a strain with promising probiotic features (L. reuteri ATCC PTA 6475). Transcriptomes of L. reuteri strains in different growth phases were monitored using strain-specific microarrays, and compared using a pan-metabolic model representing all known metabolic reactions present in these strains. Both strains contained candidate genes involved in the survival and persistence in the gut such as mucus-binding proteins and enzymes scavenging reactive oxygen species. A large operon predicted to encode the synthesis of an exopolysaccharide was identified in strain 55730. Both strains were predicted to produce health-promoting factors, including antimicrobial agents and vitamins (folate, vitamin B12). Additionally, a complete pathway for thiamine biosynthesis was predicted in strain 55730 for the first time in this species. Candidate genes responsible for immunomodulatory properties of each strain were identified by transcriptomic comparisons. The production of bioactive metabolites by human-derived probiotics may be predicted using metabolic modeling and transcriptomics. Such strategies may facilitate selection and optimization of probiotics for health promotion, disease prevention and amelioration

    Corneal Biomechanics in Ectatic Diseases: Refractive Surgery Implications.

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    BACKGROUND: Ectasia development occurs due to a chronic corneal biomechanical decompensation or weakness, resulting in stromal thinning and corneal protrusion. This leads to corneal steepening, increase in astigmatism, and irregularity. In corneal refractive surgery, the detection of mild forms of ectasia pre-operatively is essential to avoid post-operative progressive ectasia, which also depends on the impact of the procedure on the cornea. METHOD: The advent of 3D tomography is proven as a significant advancement to further characterize corneal shape beyond front surface topography, which is still relevant. While screening tests for ectasia had been limited to corneal shape (geometry) assessment, clinical biomechanical assessment has been possible since the introduction of the Ocular Response Analyzer (Reichert Ophthalmic Instruments, Buffalo, USA) in 2005 and the Corvis ST (Oculus Optikgerate GmbH, Wetzlar, Germany) in 2010. Direct clinical biomechanical evaluation is recognized as paramount, especially in detection of mild ectatic cases and characterization of the susceptibility for ectasia progression for any cornea. CONCLUSIONS: The purpose of this review is to describe the current state of clinical evaluation of corneal biomechanics, focusing on the most recent advances of commercially available instruments and also on future developments, such as Brillouin microscopy.(undefined)info:eu-repo/semantics/publishedVersio
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