Influence of alcohol use and family history of alcoholism on neural response to alcohol cues in college drinkers.

BACKGROUND: Heavy drinkers show altered functional magnetic resonance imaging (fMRI) response to alcohol cues. Little is known about alcohol cue reactivity among college age drinkers, who show the greatest rates of alcohol use disorders. Family history of alcoholism (family history positive [FHP]) is a risk factor for problematic drinking, but the impact on alcohol cue reactivity is unclear. We investigated the influence of heavy drinking and family history of alcoholism on alcohol cue-related fMRI response among college students. METHODS: Participants were 19 family history negative (FHN) light drinkers, 11 FHP light drinkers, 25 FHN heavy drinkers, and 10 FHP heavy drinkers, aged 18 to 21. During fMRI scanning, participants viewed alcohol images, nonalcohol beverage images, and degraded control images, with each beverage image presented twice. We characterized blood oxygen level-dependent (BOLD) contrast for alcohol versus nonalcohol images and examined BOLD response to repeated alcohol images to understand exposure effects. RESULTS: Heavy drinkers exhibited greater BOLD response than light drinkers in posterior visual association regions, anterior cingulate, medial frontal cortex, hippocampus, amygdala, and dorsal striatum, and hyperactivation to repeated alcohol images in temporo-parietal, frontal, and insular regions (clusters > 8,127 µl, p < 0.05). FHP individuals showed increased activation to repeated alcohol images in temporo-parietal regions, fusiform, and hippocampus. There were no interactions between family history and drinking group. CONCLUSIONS: Our results parallel findings of hyperactivation to alcohol cues among heavy drinkers in regions subserving visual attention, memory, motivation, and habit. Heavy drinkers demonstrated heightened activation to repeated alcohol images, which could influence continued drinking. Family history of alcoholism was associated with greater response to repeated alcohol images in regions underlying visual attention, recognition, and encoding, which could suggest aspects of alcohol cue reactivity that are independent of personal drinking. Heavy drinking and family history of alcoholism may have differential impacts on neural circuitry involved in cue reactivity.

The Neighborhood Health Initiative: An Academic-Clinic-Community Partnership to Address the Social Determinants of Health.

BACKGROUND: A medical school, Federally Qualified Health Center, and community-based organizations wanted to improve social determinants of health and health outcomes in an urban area with economic and health inequities. OBJECTIVE: To describe the development of the partnership called the Neighborhood Health Initiative (NHI). METHODS: Community-engaged strategy with multidisciplinary partnerships used an established framework to develop trust, assess needs, and respond. RESULTS: Co-locating primary care services, traditional healers, mental health, and legal services in response to community partners' and residents' concerns helped to create a community-centered health home. As part of the needs assessment, community health workers conducted multiple visits to build trust and ascertain community members' strengths and challenges. Selected shared projects provide solutions to locally identified problems constituted community-driven initiatives. CONCLUSIONS: The NHI is working toward sustainable strategies to improve population health in an underserved area of Austin, Texas. Consistent and frequent contact contributed to developing relationships and trust; limiting partners and objectives focused activities on meeting initial goals of the NHI. Next steps include evaluation of the three aims of the NHI and process evaluation to guide future initiatives.

Fresh for Less: Cross-Sector Collaboration for Funding, Implementation, and Evaluation of a Local Initiative to Improve Equitable Healthy Food Access.

INTRODUCTION: This study describes the cross-sector collaboration, dynamic implementation/evaluation, and implications of Fresh for Less (FFL); an equity-focused, multi-strategy healthy food access promotion program that has been implemented since 2017 in underserved communities in Austin, Texas through farmstands, mobile markets, and Healthy Corner Stores. METHODS: Annual evaluation has consisted of repeat cross-sectional quantitative surveys, qualitative customer/staff interviews, audits and cost-effective analyses. RESULTS: Farmstand/mobile market customers reported increased fresh produce consumption and high satisfaction. During COVID-19, mobile markets quickly pivoted to delivery, filling a huge need for safe and affordable grocery delivery. Healthy Corner Stores were not as successful, and this strategy was adapted and reintroduced in 2021. Audits show increased produce provision over time and that mobile markets offered increasingly competitive pricing. DISCUSSION: Fresh for Less demonstrates how cross-sector collaborators can work together to ensure that a program designed to improve equitable food access can be resilient, sustainable, and successful.

Adolescent binge drinking linked to abnormal spatial working memory brain activation: differential gender effects.

BACKGROUND: Binge drinking is prevalent during adolescence, and its effect on neurocognitive development is of concern. In adult and adolescent populations, heavy substance use has been associated with decrements in cognitive functioning, particularly on tasks of spatial working memory (SWM). Characterizing the gender-specific influences of heavy episodic drinking on SWM may help elucidate the early functional consequences of drinking on adolescent brain functioning. METHODS: Forty binge drinkers (13 females, 27 males) and 55 controls (24 females, 31 males), aged 16 to 19 years, completed neuropsychological testing, substance use interviews, and an SWM task during functional magnetic resonance imaging. RESULTS: Significant binge drinking status × gender interactions were found (p < 0.05) in 8 brain regions spanning bilateral frontal, anterior cingulate, temporal, and cerebellar cortices. In all regions, female binge drinkers showed less SWM activation than female controls, while male bingers exhibited greater SWM response than male controls. For female binge drinkers, less activation was associated with poorer sustained attention and working memory performances (p < 0.025). For male binge drinkers, greater activation was linked to better spatial performance (p < 0.025). CONCLUSION: Binge drinking during adolescence is associated with gender-specific differences in frontal, temporal, and cerebellar brain activation during an SWM task, which in turn relate to cognitive performance. Activation correlates with neuropsychological performance, strengthening the argument that blood oxygen level-dependent activation is affected by alcohol use and is an important indicator of behavioral functioning. Females may be more vulnerable to the neurotoxic effects of heavy alcohol use during adolescence, while males may be more resilient to the deleterious effects of binge drinking. Future longitudinal research will examine the significance of SWM brain activation as an early neurocognitive marker of alcohol impact to the brain on future behaviors, such as driving safety, academic performance, and neuropsychological performance.

Heavy drinking relates to positive valence ratings of alcohol cues.

A positive family history of alcohol use disorders (FH) is a robust predictor of personal alcohol abuse and dependence. Exposure to problem-drinking models is one mechanism through which family history influences alcohol-related cognitions and drinking patterns. Similarly, exposure to alcohol advertisements is associated with alcohol involvement and the relationship between affective response to alcohol cues and drinking behavior has not been well established. In addition, the collective contribution that FH, exposure to different types of problem-drinking models (e.g. parents, peers) and personal alcohol use have on appraisal of alcohol-related stimuli has not been evaluated with a large sample. We investigated the independent effects of FH, exposure to problem-drinking models and personal alcohol use on valence ratings of alcohol pictures in a college sample. College students (n = 227) completed measures of personal drinking and substance use, exposure to problem-drinking models, FH and ratings on affective valence of 60 alcohol pictures. Greater exposure to non-familial problem-drinkers predicted greater drinking among college students (beta = 0.17, P < 0.01). However, personal drinking was the only predictor of valence ratings of alcohol pictures (beta = -0.53, P < 0.001). Personal drinking level predicted valence ratings of alcohol cues over and above FH, exposure to problem-drinking models and demographic characteristics. This suggests that positive affective responses to alcohol pictures are more a function of personal experience (i.e. repeated heavy alcohol use) than vicarious learning.

Design and evaluation of a coalition-led obesity initiative to promote healthy eating and physical activity in low-income, ethnically diverse communities: the Go! Austin/Vamos! Austin initiative.

BACKGROUND: Go! Austin/Vamos! Austin (GAVA) is a coalition-led health initiative that targets low-income communities with disparities in access to healthy food and physical activity. The purpose of this initiative was to increase healthy eating and physical activity among residents by facilitating access to food and physical activity opportunities through environmental and policy changes. Although GAVA is ongoing, this paper describes the original GAVA intervention and the 5-year evaluation study (2013-2018), presenting selected baseline data obtained through its cohort sub-study. METHODS: To assess the impact of GAVA, the evaluation plan included multiple sub-studies and involved collection of quantitative, qualitative, and observational data at different levels. The main cohort sub-study followed 313 parent-child dyads over 5 years. Annually, parents completed self-administered surveys regarding awareness and use of community assets/resources as well as their diet and activities. Heights and weights also were measured. RESULTS: Cohort participants were primarily Hispanic (87%), very low-income (77%), and food insecure (58%), with high overweight/obesity prevalence among both parents (81%) and children (41%). Awareness and use of community physical activity and healthy eating resources were low, and reported barriers to using these resources were many. Engagement in physical activity and healthy eating also was low. CONCLUSIONS: Given the baseline statistics, GAVA resident teams chose and implemented strategies to address the noted barriers and low usage of community resources. This approach built community capacity and governance. Both the GAVA intervention approach and evaluation protocol can serve as models for other community initiatives to be implemented in other locations and contexts.

¿El área verde o el humedal afectan el precio de la vivienda, en un sector de Bogotá?

Diferencias en las características de la infraestructura verde pueden variar la relación entre los espacios verdes urbanos y el precio de la vivienda (PV). El objetivo de este estudio es estimar el efecto de la proximidad de áreas verdes con diseño antrópico (AVDA) y de un humedal, sobre los valores del mercado de vivienda. Mediante uso de sistemas de información geográfica se determinó el tamaño de áreas verdes próximas al humedal y otros atributos de localización de las viviendas; los precios de los inmuebles se obtuvieron en el mercado de finca raíz en Bogotá. Con mínimos cuadrados ordinarios se relacionó el PV con atributos ambientales, de localización y socioeconómicos; el Índice de Moran, modelos de contigüidad y error espaciales permitieron analizar la dependencia espacial de los datos. El AVDA y no el humedal, estuvo significativamente asociada con el PV Las regresiones realizadas mostraron la ausencia de dependencia espacial entre los datos, así como una asociación positiva del PV con las AVDA, el área del inmueble y el número de alcobas. Mientras que la edad de las viviendas y la distancia al Comando de Atención Inmediata (CAI) tuvieron una asociación negativa con el PV. Estos resultados muestran que los residentes locales pagan más por vivir cerca a áreas con AVDA y tienen implicaciones para la planificación urbana de estratos socioeconómicos altos. Los valores estimados en este trabajo pueden ser utilizados para alimentar un análisis costo-beneficio en evaluaciones para la construcción, ampliación y rehabilitación de espacios verdes urbanos. Se recomienda realizar un estudio semejante, en vecindarios de menores ingresos económicos que permitan definir también la tipología de AVDA factible de pagar y que al mismo tiempo proporcione servicios ecosistémicos culturales.

Differences in the characteristics of green infrastructure can vary the relationship between urban green spaces and housing prices. The objective of this study is to estimate the effect of the proximity of anthropically designed green areas and a wetland on housing market values. Using geographic information systems, the size of green areas near the wetland and other attributes of housing location were determined; property prices were obtained from the real estate market in Bogota. Ordinary least squares was used to relate the housing prices to environmental, location and socioeconomic attributes; the Moran Index, contiguity models and spatial error models were used to analyze the spatial dependence of the data. The anthropically designed green areas, and not the wetland, was significantly associated with the housing prices. The regressions performed showed the absence of spatial dependence among the data, as well as a positive association of housing prices with anthropically designed green areas, property area and number of alcoves. While the age of the dwellings and the distance to the Immediate Attention Command had a negative association with housing prices. These results show that local residents pay more to live near areas with anthropically designed green areas and have implications for urban planning for high socioeconomic strata. The values estimated in this work can be used to feed a cost-benefit analysis in evaluations for the construction, expansion, and rehabilitation of urban green spaces. It is recommended that a similar study be conducted in lower income neighborhoods to define the type of anthropically designed green areas that can be afforded and at the same time provide cultural ecosystem services.

As diferenças nas características da infra-estrutura verde podem variar a relação entre o espaço verde urbano e os preços da habitação (PH). O objetivo deste estudo é estimar o efeito da proximidade de áreas verdes antropogenicamente projetadas (AVAP) e de um pântano sobre os valores do mercado imobiliário. Usando sistemas de informação geográfica, foi determinado o tamanho das áreas verdes próximas ao pântano e outros atributos de localização habitacional; os preços dos imóveis foram obtidos do mercado imobiliário em Bogotá. Os mínimos quadrados comuns foram usados para relacionar a PV aos atributos ambientais, de localização e sócio-econômicos; os modelos do Índice Moran, contiguidade e erro espacial foram usados para analisar a dependência espacial dos dados. A AVAP e não a zona úmida, foi significativamente associada à PV. As regressões mostraram a ausência de dependência espacial entre os dados, bem como uma associação positiva de PH com AVAP, área da propriedade e número de alcovas. Enquanto a idade das moradias e a distância até o Comando de Atenção Imediata (CAI) tinham uma associação negativa com o PV Estes resultados mostram que os residentes locais pagam mais para viver perto de áreas com AVAP e têm implicações no planejamento urbano para altos estratos sócio-econômicos. Os valores estimados neste trabalho podem ser usados para alimentar uma análise de custo-benefício em avaliações para a construção, extensão e reabilitação de espaços verdes urbanos. Recomenda-se que seja realizado um estudo semelhante nos bairros de menor renda para também definir o tipo de AVAP que pode ser oferecido ao mesmo tempo em que fornece serviços culturais ecossistêmicos.

Designing Place-Based Interventions for Sustainability and Replicability: The Case of GO! Austin/VAMOS! Austin.

Place-based health efforts account for the role of the community environment in shaping decisions and circumstances that affect population well-being. Such efforts, rooted as they are in the theory that health is socially determined, mobilize resources for health promotion that are not typically used, and offer a more informed and robust way of promoting health outcomes within a community. Common criticisms of place-based work include the difficulty of replication, since engagement is so specific to a place, and limited sustainability of the work, in the absence of continued institutional structures, both within the community and supporting structures outside the community, to keep these initiatives resilient. This paper describes a place-based initiative, GO! Austin/VAMOS! Austin (GAVA), which was designed to harness the strengths of place-based work-namely, its specificity to place and community. From the start, the project was designed to balance this specificity with a focus on developing and utilizing a standardized set of evidence-informed implementation and evaluation approaches and tools that were flexible enough to be modified for specific settings. This was accompanied by an emphasis on leadership and capacity building within resident leaders, which provided for informed intervention and demand building capacity, but also for longevity as partners, philanthropic, and otherwise, moved in and out of the work.

Prospective changes in neural alcohol cue reactivity in at-risk adolescents.

Adolescence represents an ideal time for elucidating the etiology of cue reactivity profiles. This study examined the influence of three risk factors consistently associated with heavy adolescent drinking on alcohol cue reactivity. Youth were first assessed while still naïve to alcohol (12-14 years old) and followed after transitioning into alcohol use (17-21 years old). The effects of family history of substance use disorder, sex, and history of early of dating (i.e., before 14 years of age) on BOLD response contrast to alcohol picture cues were examined in a linear mixed model, controlling for age and alcohol use patterns at follow-up. Activation to alcohol picture cues differed as a function of risk factor and time. At baseline, family history positive youth showed greater activation to alcohol cues than family history negative peers in the right middle occipital and anterior cingulate gyri. Youth with a history of early-dating showed greater activation to alcohol cues, compared to non-early daters, in the left anterior cingulate/white matter region. Girls showed greater activation to alcohol than boys at baseline in left middle frontal gyrus. At follow-up, after drinking started, patterns reversed for each risk factor. These results indicate that even prior to initiating alcohol use, adolescents showed differences in activation to alcohol cues based on their family history, dating history, and sex.

Adolescent heavy drinkers' amplified brain responses to alcohol cues decrease over one month of abstinence.

INTRODUCTION: Heavy drinking during adolescence is associated with increased reactivity to alcohol related stimuli and to differential neural development. Alcohol cue reactivity has been widely studied among adults with alcohol use disorders, but little is known about the neural substrates of cue reactivity in adolescent drinkers. The current study aimed to identify changes in blood-oxygen level dependent (BOLD) signal during a cue reactivity task pre- and post-monitored abstinence from alcohol. METHOD: Demographically matched adolescents (16.0-18.9 years, 54% female) with histories of heavy episodic drinking (HD; n=22) and light or non-drinking control teens (CON; n=16) were recruited to participate in a month-long study. All participants completed a functional Magnetic Resonance Imaging (fMRI) scan with an alcohol cue reactivity task and substance use assessments at baseline and after 28 days of monitored abstinence from alcohol and drugs (i.e., urine toxicology testing every 48-72 h). Repeated-measure analysis of variance (ANOVA) examined main effects of group, time, and group×time interactions on BOLD signal response in regions of interest defined by functional differences at baseline. RESULTS: The HD group exhibited greater (p<.01) BOLD activation than CON to alcohol cues relative to neutral cues in all regions of interest (ROIs; bilateral striatum/globus pallidus, left anterior cingulate, bilateral cerebellum, and parahippocampal gyrus extending to the thalamus/substantia nigra) across time points. Group×time effects showed that HD exhibited greater BOLD activation to alcohol cues than CON at baseline in left anterior cingulate cortex and in the right cerebellar region, but these decreased to non-significance after one month of monitored abstinence. CONCLUSIONS: In all ROIs examined, HD exhibited greater BOLD response than CON to alcohol relative to neutral beverage picture cues at baseline, indicating heightened cue reactivity to alcohol cues in heavy drinking adolescents prior to the onset of any alcohol use diagnosis. Across the majority of these brain regions, differences in BOLD response were no longer apparent following a month of abstinence, suggesting a decrease in alcohol cue reactivity among adolescent non-dependent heavy drinkers as a consequence of abstaining from alcohol. These results highlight the malleability of adolescent brain function despite no formal intervention targeting cue reactivity. Increased understanding of the neural underpinnings of cue reactivity could have implications for prevention and intervention strategies in adolescent heavy alcohol users.

An FMRI study of response inhibition in youths with a family history of alcoholism.

Disinhibition among alcoholics may precede or result from alcohol use disorders (AUDs). It remains unclear how disinhibition might contribute to AUD risk among youths with a family history of alcoholism (FHP). We used functional magnetic resonance imaging (fMRI) to explore inhibition-related neural risk factors for AUD. Participants were 12- to 14-year-old nondrinkers, including 12 FHP youths and 14 youths with no family history of alcoholism (FHN). Youths performed a go/no-go task during fMRI acquisition. At a conservative threshold, FHN youths showed less inhibitory response than FHP youths in the left middle frontal gyrus, despite similar task performance between groups. Using a more liberal threshold, FHP youths also demonstrated less response in additional frontal regions. These preliminary findings suggest that FHP youths show less inhibitory frontal response than FHN youths. Altered neural activation among FHP youths may underlie subsequent disinhibition and could be related to the AUD risk.

Level of response to alcohol and brain response during visual working memory.

OBJECTIVE: This study examined neural correlates of the low level of response to alcohol using functional magnetic resonance imaging (FMRI) during a challenging visual working memory task. METHOD: Participants were healthy adolescents (N = 35) with a range of drinking patterns recruited from local high schools. After a minimum 5 days of abstinence from alcohol and other drugs, FMRI, neuropsychological testing and the Self-Rating of the Effects of Alcohol were administered. RESULTS: Self-report of initial level of response to alcohol was significantly predicted by FMRI blood oxygen level dependent (BOLD) response to the visual working memory task in the right prefrontal and bilateral anterior cingulate region (12% of unique variance, p < .05) and right cerebellum and parahippocampal gyrus (17% of unique variance, p < .01), above and beyond effects accounted for by drinks consumed per month, age, gender and ethnicity. CONCLUSIONS: Young people who report having needed more alcohol to achieve specific effects during early drinking experiences show higher levels of brain response during visual working memory, perhaps suggesting less capacity to adjust cognitive processing to contextual demands.

Group medication management for buprenorphine/naloxone in opioid-dependent veterans.

OBJECTIVE: Substance use disorders are a key concern among US veterans. Substance use disorder pharmacotherapies with support for effectiveness are limited. Buprenorphine/naloxone (Suboxone) is an effective opioid replacement treatment option for opioid use disorder when used as part of a comprehensive treatment program. In June 2011, the Veterans Affairs San Diego Healthcare System began using a group format to prescribe buprenorphine/naloxone. This study aimed at examining outcomes of retention rates and percentage opioid negative urine samples. Results were compared for veteran patients seen in group versus individual formats. METHODS: This retrospective chart review included data from 32 patients who were prescribed buprenorphine/naloxone between a 3-year window (ie, January 1, 2010, and December 31, 2012). RESULTS: Overall results were 46% retention in treatment after 1 year, and 94% of opioid urine samples were negative. More patients seen in group were retained in treatment at 1 year compared with those seen individually (69% vs 27%, respectively; P < 0.03). CONCLUSIONS: This study found that veterans prescribed buprenorphine/naloxone in a group setting as part of a drug and alcohol treatment program were retained in treatment longer than veterans prescribed this medication individually. Because of inherent limitations in the study design, no causality can be determined; however, given the results found here, group medication management of buprenorphine/naloxone should be explored further.

Changes in alcohol-related brain networks across the first year of college: a prospective pilot study using fMRI effective connectivity mapping.

The upsurge in alcohol use that often occurs during the first year of college has been convincingly linked to a number of negative psychosocial consequences and may negatively affect brain development. In this longitudinal functional magnetic resonance imaging (fMRI) pilot study, we examined changes in neural responses to alcohol cues across the first year of college in a normative sample of late adolescents. Participants (N=11) were scanned three times across their first year of college (summer, first semester, second semester), while completing a go/no-go task in which images of alcoholic and non-alcoholic beverages were the response cues. A state-of-the-art effective connectivity mapping technique was used to capture spatiotemporal relations among brain regions of interest (ROIs) at the level of the group and the individual. Effective connections among ROIs implicated in cognitive control were greatest at the second assessment (when negative consequences of alcohol use increased), and effective connections among ROIs implicated in emotion processing were lower (and response times were slower) when participants were instructed to respond to alcohol cues compared to non-alcohol cues. These preliminary findings demonstrate the value of a prospective effective connectivity approach for understanding adolescent changes in alcohol-related neural processes.

Carbono almacenado en páramo andino

A pesar de la importancia del ecosistema de páramo en el ciclo global de carbono no se dispone de una síntesis que permita diferenciar si es la biomasa vegetal o el suelo el componente que acumula la mayor cantidad de carbono. En este documento se busca integrar los aspectos fundamentales relacionados con el carbono almacenado en el ecosistema de páramo, a través de: 1) Revisar las estimaciones de carbono en biomasa aérea y suelo reportadas por la literatura para el ecosistema de páramo; 2) Examinar los efectos producidos por la actividad agropecuaria en el carbono almacenado en el páramo y 3) Identificar prácticas que reducen las emisiones de carbono en el páramo. Se revisaron artículos en bases de datos como Science Direct Springerlink, Willey Online Library y Google Scholar El componente que almacena mayor cantidad de carbono en páramo es el suelo, con contenidos entre 119 y 397 t/ha en los primeros 40 cm de profundidad. Mientras que la biomasa aérea varía entre 13,21 y 183 t/ha. Es necesario incrementar las investigaciones sobre carbono orgánico en suelos de páramo. Esta información podría contribuir a apoyar acciones tendientes a vincular los ecosistemas de paramo al mercado de carbono.

Despite the importance of the paramo ecosystem in the global carbon cycle, there is not an available synthesis for identifying if plant bio-mass or soil accumulates the maximum amount of carbon. The purpose of this document is to focus on paramo ecosystem stock carbon, throught: 1) to review estimates for the abovegroundbiomass and soil organic carbón; 2) to examine the agricultural production effects on carbon storage, and 3) to identify management practices for reducing carbon emissions in the paramo ecosystem. We searched papers about carbon storage in paramo in databases like Science Direct, Springerlink, Willey Online Library y Google Scholar. Soil stored more carbon than aboveground biomass. Soil carbon organic (SOC) between 119 and 397 t/ha was storaged in the upper 40 cm. Meanwhile, aboveground biomass carbon varied between 13,21 y 183 t/ha. More studies about SOC are requiered. This information could contribute to support actions over the entailment of paramo ecosystem in carbon markets.

Apesar da importância do ecossistema de páramo no ciclo global do carbono não está disponível uma síntese para diferenciar se é a biomassa vegetal ou solo, o componente que acumula a maior parte do carbono. Este trabalho procura integrar os aspectos fundamentais do carbono armazenado no ecossistema páramo, por meio de: 1) Rever as estimativas de carbono na biomassa e no solo relatado pela literatura para o ecossistema páramo; 2) Analisar os efeitos da atividade agrícola no carbono armazenado no páramo e 3) Identificar práticas que reduzem as emissões de carbono no páramo. Artigos foram revistos em bases de dados, tais como Science Direct SpringerLink Wiley Online Library e Google Scholar. O componente que armazena a maior parte do carbono é o solo, com contidos entre 119 e 397 t/ha nos primeiros 40 cm de profundidade. Enquanto a biomassa varia entre 13,21 e 183 t / ha. É preciso acrescentar a pesquisa sobre carbono orgânico no solo em páramo. Esta informação poderia ajudar a apoiar as ações para vincular os ecossistemas de Páramo ao mercado de carbono.

Binge drinking differentially affects adolescent male and female brain morphometry.

RATIONALE: Adolescent binge drinking is concerning, as important neurodevelopments occur during this stage. Previous research suggests that binge drinking may disrupt typical brain development, and females may be particularly vulnerable. OBJECTIVES: We used magnetic resonance imaging (MRI) to examine cortical thickness in adolescent females and males with and without histories of binge drinking. METHODS: Participants (N = 59) were 16-19-year-old adolescents recruited from local schools. Recent binge drinkers (n = 29, 48% female) were matched to non-drinkers (n = 30, 50% female) on age, gender, pubertal development, and familial alcoholism. Participants completed a neuropsychological battery and MRI session. Cortical surfaces were reconstructed with FreeSurfer. RESULTS: Binge × gender interactions (p < .05) were seen for cortical thickness in four left frontal regions: frontal pole, pars orbitalis, medial orbital frontal, and rostral anterior cingulate. For all interactions, female bingers had thicker cortices than female controls, while male bingers had thinner cortices than male controls. Thicker left frontal cortices corresponded with poorer visuospatial, inhibition, and attention performances for female bingers (r = -0.69 to 0.50, p < 0.05) and worse attention for male bingers (r = -0.69, p = 0.005). CONCLUSIONS: Adolescent females with recent binge drinking showed ~8% thicker cortices in left frontal regions than demographically similar female non-drinkers, which was linked to worse visuospatial, inhibition, and attention performances. In contrast, adolescent binge-drinking males showed ~7% thinner cortices in these areas than non-drinking males. These cross-sectional data suggest either different gray matter risk factors for males as for females toward developing heavy drinking, or differential adverse sequelae.

Frontoparietal connectivity in substance-naïve youth with and without a family history of alcoholism.

Frontoparietal connections underlie key executive cognitive functions. Abnormalities in the frontoparietal network have been observed in chronic alcoholics and associated with alcohol-related cognitive deficits. It remains unclear whether neurobiological differences in frontoparietal circuitry exist in substance-naïve youth who are at-risk for alcohol use disorders. This study used functional connectivity magnetic resonance imaging and diffusion tensor imaging to examine frontoparietal connectivity and underlying white matter microstructure in 20 substance-naïve youth with a family history of alcohol dependence and 20 well-matched controls without familial substance use disorders. Youth with a family history of alcohol dependence showed significantly less functional connectivity between posterior parietal and dorsolateral prefrontal seed regions (ps<.05), as compared to family history negative controls; however, they did not show differences in white matter architecture within tracts subserving frontoparietal circuitry (ps>.34). Substance-naïve youth with a family history of alcohol dependence show less frontoparietal functional connectivity in the absence of white matter microstructural abnormalities as compared to youth with no familial risk. This may suggest a potential neurobiological marker for the development of substance use disorders.

Brain response to working memory over three years of adolescence: influence of initiating heavy drinking.

OBJECTIVE: Many adolescents engage in heavy alcohol use. The aim of this study was to disentangle whether brain abnormalities seen in adolescent heavy drinkers are a consequence of heavy drinking, a preexisting risk factor for initiation of alcohol use, or both. METHOD: Study 1 used cross-sectional functional magnetic resonance imaging (fMRI) visual working-memory (VWM) data from 15- to 19-year-olds (20 heavy drinkers, 20 controls) to identify brain regions affected by heavy adolescent alcohol use. Study 2 used longitudinal fMRI VWM data from 12- to 16-year-olds imaged before the onset of drinking and imaged again on the same scanner approximately 3 years later. Those who had transitioned into heavy drinking (n = 20) were matched to continuous nondrinkers (n = 20) on baseline alcohol risk and developmental factors (N = 40; 80 scans). RESULTS: Study 1 found that heavy drinkers exhibited more frontal and parietal but less occipital activation than controls, defining the regions of interest for Study 2. In Study 2, adolescents who later transitioned into heavy drinking showed less fMRI response contrast at baseline than continuous nondrinkers, which increased after the onset of heavy drinking, in frontal (1,431 µL, p = .003; η² = .19) and parietal (810 µL, p = .005; η²= .23) regions, as in Study 1. Lower baseline activation in the frontal and parietal regions predicted subsequent substance use, more so than commonly observed predictors of youth drinking (p < .05). CONCLUSIONS: Adolescents who initiated heavy drinking showed different brain activation before the onset of drinking, then less efficient information processing after high-dose alcohol use started. This suggests neural response patterns that could be risk factors for future substance use and also supports prior neuropsychological reports indicating that initiating heavy episodic drinking in adolescence may be followed by subtle alterations in brain functioning.

Neural activation during inhibition predicts initiation of substance use in adolescence.

BACKGROUND: Problems inhibiting non-adaptive behaviors have been linked to an increased risk for substance use and other risk taking behaviors in adolescence. This study examines the hypothesis that abnormalities in neural activation during inhibition in early adolescence may predict subsequent substance involvement. METHODS: Thirty eight adolescents from local area middle schools, ages 12-14, with very limited histories of substance use, underwent functional magnetic resonance imaging (fMRI) as they performed a go/no-go task of response inhibition and response selection. Adolescents and their parents were then followed annually with interviews covering substance use and other behaviors. Based on follow-up data, youth were classified as transitioning to heavy use of alcohol (TU; n=21), or as healthy controls (CON; n=17). RESULTS: At baseline, prior to the onset of use, youth who later transitioned into heavy use of alcohol showed significantly less activation than those who went on to remain non to minimal users throughout adolescence. Activation reductions in TU at baseline were seen on no-go trials in 12 brain regions, including right inferior frontal gyrus, left dorsal and medial frontal areas, bilateral motor cortex, cingulate gyrus, left putamen, bilateral middle temporal gyri, and bilateral inferior parietal lobules (corrected p<.01, each cluster ≥32 contiguous voxels). CONCLUSIONS: These results support the hypothesis that less neural activity during response inhibition demands predicts future involvement with problem behaviors such as alcohol and other substance use.

Alcohol cue reactivity task development.

BACKGROUND: The physiological and cognitive reactions provoked by alcohol cues, as compared to non-alcohol cues, can predict future drinking. Alcohol cue reactivity tasks have been developed; however, most were created for use with alcohol use disordered individuals and utilize limited or only partially standardized stimuli. This project systematically created an alcohol cue reactivity task for studies with non-drinkers, using well-characterized stimuli. OBJECTIVES: We comprehensively standardized 60 alcohol and 60 non-alcohol beverage pictures using ratings from young non-drinkers (N=82) on affective and perceptual features. RESULTS: A statistical matching approach yielded 26 matched alcohol-non-alcohol picture pairs matched on valence, arousal, image complexity, brightness, and hue. The task was piloted and further refined to 22 picture pairs. An 8-minute, 32-second event-related task was created using a random stimulus function for optimized condition timing and systematic presentation of the images. CONCLUSIONS: The long-term objectives of this project are to utilize this task with non-drinking youth to investigate how reactivity to alcohol stimuli may predict alcohol use initiation and escalation, to help identify the role of exposure to alcohol stimuli on the subsequent development of alcohol-related problems.