Friendship selection and influence processes for popularity in early and mid-adolescents

Introduction This study examined the effect of popularity levels on friendship selection and friends' influence on popularity levels in early and mid-adolescence. Methods Participants were 4205 Spanish adolescents (M-age = 13.1 years at Wave 1; 48% girls) belonging to 160 classrooms in two waves. Adolescents were asked about their friendships and the popularity of their classmates. Results Longitudinal social network analyses showed that adolescents preferred similarly popular peers as friends. High popular classmates were more attractive as friends, particularly in early adolescence. Popular adolescents were more selective in their friendship nominations and adolescents with popular friends became more popular over time. These two effects were only significant in mid-adolescents, although comparative analyses showed a similar tendency at both age groups. Conclusions This study highlights the importance of popularity levels in adolescents' friendship selection and suggests that popularity, at the individual and group level, plays a relevant role in social development. Implications adapted to the different selection and influence processes in early and mid-adolescence are discussed

Interventions in the first 1000 days to prevent childhood obesity: a systematic review and quantitative content analysis

Background: Childhood obesity poses a global health challenge. In recent years, there has been an increase in interventions that begin in pregnancy, putting the concept of early programming and early risk factors into practice. The present study aims to update the findings regarding interventions in the first 1000 days of life. Methods: A systematic review based on the PRISMA guidelines was carried out in PubMed, WoS, Scopus and CINAHL to obtain the articles to be analysed. We included those studies published between 2016 and 2021. Human interventions that started within the first 1000 days of life and acted on at least one programming factor were included. Once selected, coding and quantitative content analysis was carried out to obtain a profile of the interventions during the first 1000 days. Results: From all screened articles, 51 unique interventions, which met the selection criteria, were included. The majority of interventions (81%) took place in high-income areas. Almost all (86%) were targeted at the general population. The majority (54%) started in the second trimester of pregnancy. A clear majority (61%) ended at the time of birth. 44% of the interventions included all pregnant women. Only 48% of these interventions were focused on improving the nutritional status of the offspring in the short term. Most interventions collected the baby's weight at birth (68%). Conclusions: It can be concluded that current interventions are not covering as many aspects as they should. Future research should be conducted more frequently in developing countries and target disadvantaged groups. These interventions should include all pregnant women, regardless of their nutritional status, aiming to cover as many programming factors as possible and extending through the first 1000 days of life, with body mass index or skinfolds as measures of effectiveness during this period.11 página

Brain-Derived Neurotrophic Factor Levels in Cord Blood from Growth Restricted Fetuses with Doppler Alteration Compared to Adequate for Gestational Age Fetuses

Background and Objectives: Fetal growth restriction (FGR) is a severe obstetric disease characterized by a low fetal size entailing a set of undesired consequences. For instance, previous studies have noticed a worrisome association between FGR with an abnormal neurodevelopment. However, the precise link between FGR and neurodevelopmental alterations are not yet fully understood yet. Brain-derived neurotrophic factor (BDNF) is a critical neurotrophin strongly implicated in neurodevelopmental and other neurological processes. In addition, serum levels of BDNF appears to be an interesting indicator of pathological pregnancies, being correlated with the neonatal brain levels. Therefore, the aim of this study is to analyze the blood levels of BDNF in the cord blood from fetuses with FGR in comparison to those with weight appropriate for gestational age (AGA). Materials and Methods: In this study, 130 subjects were recruited: 91 in group A (AGA fetuses); 39 in group B (16 FGR fetuses with exclusively middle cerebral artery (MCA) pulsatility index (PI) 95th percentile). Serum levels of BDNF were determined through ELISA reactions in these groups. Results: Our results show a significant decrease in cord blood levels of BDNF in FGR and more prominently in those with UA PI >95th percentile in comparison to AGA. FGR fetuses with exclusively decreased MCA PI below the 5th percentile also show reduced levels of BDNF than AGA, although this difference was not statistically significant. Conclusions: Overall, our study reports a potential pathophysiological link between reduced levels of BDNF and neurodevelopmental alterations in fetuses with FGR. However, further studies should be conducted in those FGR subjects with MCA PI < 5th percentile in order to understand the possible implications of BDNF in this group.Depto. de Salud Pública y Materno - InfantilFac. de MedicinaTRUEUnión EuropeaComunidad de MadridInstituto de Salud Carlos IIIHalekulani S.LFundación Santiago Dexeus Fontpu

First use of a compound-specific stable isotope (CSSI) technique to trace sediment transport in upland forest catchments of Chile.

Land degradation is a problem affecting the sustainability of commercial forest plantations. The identification of critical areas prone to erosion can assist this activity to better target soil conservation efforts. Here we present the first use of the carbon-13 signatures of fatty acids (C14 to C24) in soil samples for spatial and temporal tracing of sediment transport in river bodies of upland commercial forest catchments in Chile. This compound-specific stable isotope (CSSI) technique was tested as a fingerprinting approach to determine the degree of soil erosion in pre-harvested forest catchments with surface areas ranging from 12 to 40ha. For soil apportionment a mixing model based on a Bayesian inference framework was used (CSSIAR v.2.0). Approximately four potential sediment sources were used for the calculations of all of the selected catchments. Unpaved forestry roads were shown to be the main source of sediment deposited at the outlet of the catchments (30-75%). Furthermore, sampling along the stream channel demonstrated that sediments were mainly comprised of sediment coming from the unpaved roads in the upper part of the catchments (74-98%). From this it was possible to identify the location and type of primary land use contributing to the sediment delivered at the outlet of the catchments. The derived information will allow management to focus efforts to control or mitigate soil erosion by improving the runoff features of the forest roads. The use of this CSSI technique has a high potential to help forestry managers and decision makers to evaluate and mitigate sources of soil erosion in upland forest catchments. It is important to highlight that this technique can also be a good complement to other soil erosion assessment and geological fingerprinting techniques, especially when attempting to quantify (sediment loads) and differentiate which type of land use most contributes to sediment accumulation

Sediment source apportionment following wildfire in an upland commercial forest catchment

File replaced (incorrect version) on 09/05/2022 by KT (LDS).Purpose: Wildfires can have major impacts on water scarcity and water quality linked to off-site transfer of polluting ash and nutrients. Understanding sediment sources in burnt landscapes can help to develop mitigation strategies, especially in catchments planted with introduced species that are prone to fire. We investigated sediment sources activated by post-fire rainfall in a small-forested catchment that was impacted by a severe wildfire. The aim was to use environmental radionuclides and elemental geochemistry as tracers to apportion sediment sources within burnt plantation systems. Methods: Surficial (0–2 cm) topsoil (n = 9), sub-surficial (2–4 cm) topsoil (i.e. below the burnt layer; n = 8) samples from burnt hillslopes and forest roads (n = 5) and stream banks (n = 5) soil samples were taken in the Quivolgo catchment, El Maule region, Chile. Sediment samples (n = 9) were collected from behind a v-notched weir on three dates after the fire: May 2017, July 2017 and October 2017. Soil and sediment samples were analysed by gamma spectrometry and wavelength-dispersive X-ray fluorescence (WD-XRF) used to obtain tracer properties. These were evaluated visually and statistically to identify potential non-conservative tracers. Sediment apportionment was undertaken using the MixSIAR mixing model. Results: The tracer selection procedure resulted in ten tracers being used for sediment apportionment. Tracer suitability was based on (i) weak and non-significant linear relationship between tracer concentrations and specific surface area (SSA) and soil organic matter (SOM), and (ii) conservative behaviour supported by the inclusion of sediment samples within source convex hull. Sediments from sub-surface layer (2–4 cm) were the dominant source during the first two periods contributing 55 ± 11 and 78 ± 10% respectively, whereas road contribution was only important in the last period (71 ± 14%). Apportionment showed a shift in sediment source (i.e. from forest roads to hillslopes) compared to a previous study in the same catchment before wildfire. The main driver of erosion was attributed to overland flow convergence and consequent rill erosion across burnt hillslopes. Conclusion: The study demonstrated combined use of environmental radionuclides with elemental geochemistry for sediment apportionment within burnt forest plantations and highlighted a switch in predominant source (e.g. sub-surface burnt soil) activated by post-fire rainfall events. The findings in this research will help forest companies to develop strategies to reduce off-site impacts of sediment release after wildfire in forest plantations

Enhanced mitochondrial activity reshapes a gut microbiota profile that delays NASH progression

[EN] Background and Aims: Recent studies suggest that mitochondrial dysfunction promotes progression to NASH by aggravating the gut-liver status. However, the underlying mechanism remains unclear. Herein, we hypothesized that enhanced mitochondrial activity might reshape a specific microbiota signature that, when transferred to germ-free (GF) mice, could delay NASH progression. Approach and Results: Wild-type and methylation-controlled J protein knockout (MCJ-KO) mice were fed for 6 weeks with either control or a choline-deficient, L-amino acid–defined, high-fat diet (CDA-HFD). One mouse of each group acted as a donor of cecal microbiota to GF mice, who also underwent the CDA-HFD model for 3 weeks. Hepatic injury, intestinal barrier, gut microbiome, and the associated fecal metabolome were then studied. Following 6 weeks of CDA-HFD, the absence of methylation-controlled J protein, an inhibitor of mitochondrial complex I activity, reduced hepatic injury and improved gut-liver axis in an aggressive NASH dietary model. This effect was transferred to GF mice through cecal microbiota transplantation. We suggest that the specific microbiota profile of MCJ-KO, characterized by an increase in the fecal relative abundance of Dorea and Oscillospira genera and a reduction in AF12, Allboaculum, and [Ruminococcus], exerted protective actions through enhancing short-chain fatty acids, nicotinamide adenine dinucleotide (NAD+) metabolism, and sirtuin activity, subsequently increasing fatty acid oxidation in GF mice. Importantly, we identified Dorea genus as one of the main modulators of this microbiota-dependent protective phenotype. Conclusions: Overall, we provide evidence for the relevance of mitochondria–microbiota interplay during NASH and that targeting it could be a valuable therapeutic approach.S

Mitochondrial bioenergetics boost macrophage activation, promoting liver regeneration in metabolically compromised animals

Background and aims: Hepatic ischemia-reperfusion injury (IRI) is the leading cause of early posttransplantation organ failure as mitochondrial respiration and ATP production are affected. A shortage of donors has extended liver donor criteria, including aged or steatotic livers, which are more susceptible to IRI. Given the lack of an effective treatment and the extensive transplantation waitlist, we aimed at characterizing the effects of an accelerated mitochondrial activity by silencing methylation-controlled J protein (MCJ) in three preclinical models of IRI and liver regeneration, focusing on metabolically compromised animal models. Approach and results: Wild-type (WT), MCJ knockout (KO), and Mcj silenced WT mice were subjected to 70% partial hepatectomy (Phx), prolonged IRI, and 70% Phx with IRI. Old and young mice with metabolic syndrome were also subjected to these procedures. Expression of MCJ, an endogenous negative regulator of mitochondrial respiration, increases in preclinical models of Phx with or without vascular occlusion and in donor livers. Mice lacking MCJ initiate liver regeneration 12 h faster than WT and show reduced ischemic injury and increased survival. MCJ knockdown enables a mitochondrial adaptation that restores the bioenergetic supply for enhanced regeneration and prevents cell death after IRI. Mechanistically, increased ATP secretion facilitates the early activation of Kupffer cells and production of TNF, IL-6, and heparin-binding EGF, accelerating the priming phase and the progression through G1 /S transition during liver regeneration. Therapeutic silencing of MCJ in 15-month-old mice and in mice fed a high-fat/high-fructose diet for 12 weeks improves mitochondrial respiration, reduces steatosis, and overcomes regenerative limitations. Conclusions: Boosting mitochondrial activity by silencing MCJ could pave the way for a protective approach after major liver resection or IRI, especially in metabolically compromised, IRI-susceptible organs.Funding information: Supported by grants from Ministerio de Ciencia, Innovación y Universidades MICINN (PID2020-117116RB-100, RTI2018-096759-A-100, RTI2018-095114-B-I00, PID2019-108977RB-100 and RTI2018-095700-B100, integrado en el Plan Estatal de Investigación Científica y Técnica y Innovación, cofinanciado con Fondos FEDER, to M.L.M.-C., T.C.D., C.P., P.M.-S., and N.G.A.A., respectively), Subprograma Retos Colaboración RTC2019-007125-1; Fundación Científica de la Asociación Española Contra el Cáncer (AECC Scientific Foundation) Rare Tumor Calls 2017 (to M.L.M.-C.); Asociación Española contra el Cáncer (to T.C.D. and M.S.-M); La Caixa Foundation Program (HR17-00601, to M.L.M.-C.), Proyectos Investigación en Salud DTS20/00138 (to M.L.M.-C.); Departamento de Industria del Gobierno Vasco (to M.L.M.-C.); Departamento de Educación del Gobierno Vasco (to N.G.-U. and J.S.); Acción Estratégica Ciber Emergentes 2018 (Ciberehd-ISCIII) and Gilead Sciences International Research Scholars Program in Liver Disease (to M.V.-R.); Ciberehd_ISCIII_MINECO is funded by the Instituto de Salud Carlos IIIAcknowledgments: We thank MINECO for the Severo Ochoa Excellence Accreditation to CIC bioGUNE (SEV-2016-0644). We acknowledge Begoña Rodríguez Iruretagoyena for the technical support provided