ABSTRACT
BACKGROUND: One of the ecological impacts of exotic plant invasions may be alteration of the soil microbial community, which may cause changes to the diversity, richness and function of these communities. In order to explore to what extent invasive plants affect the soil microbial community, we performed a meta-analysis based on 46 scientific articles to document the effect of invasive plants on species richness and diversity of bacteria and fungi. We conducted our study across a range of invaded ecosystems including native communities, and evaluated biomass, richness and diversity. We use a random effects model to determine the increase or decrease in the values of the response variables in the presence of invasive plants. RESULTS: The results indicated that the response variable that changed with the invasion of plants was the diversity of bacteria. Bacterial diversity in the soil increases with the presence of invasive plants, specifically herbaceous plants producing allelopathic substances growing in forest ecosystems of temperate zones. CONCLUSIONS: We provide evidence that invasive plants affect the soil biota differentially; however, it is important to consider more variables such as the N and C cycles, since these processes are mediated by soil biota and litter, and chemical compounds released by plants influence them. Changes in bacterial diversity have consequences for the nutrient cycle, enzymatic activity, mineralization rates and soil carbon and nitrogen content.
Subject(s)
Microbiota , Soil , Biodiversity , Plants , Soil MicrobiologyABSTRACT
Resumen: Antecedentes: Dentro del estudio de la estructura del TDAH existe un debate en curso sobre si las diferencias fenotípicas se deben a diferencias en la gravedad de los síntomas de falta de atención, hiperactividad e impulsividad a lo largo de un continuo subyacente o si las diferencias lo que reflejan son subtipos cualitativamente distintos con etiologías únicas. Objetivo: Analizar si los comportamientos de inatención, hiperactividad e impulsividad en población infantil reflejan presentaciones cualitativamente distintas dentro del TDAH, variaciones a lo largo de un único continuo de gravedad o diferentes niveles de gravedad dentro de las representaciones. Método: Se llevó a cabo un estudio a través de análisis factorial confirmatorio (AFC), análisis de clases latentes (ACL) y modelos factoriales mixtos (MFM) del fenotipo del TDAH según los datos recogidos mediante el inventario de comportamiento infantil y adolescente (CABI) de 632 participantes (M=10,46 años; DT=2,35) de la ciudad de Talca (Chile) en población general. Resultados: De los 16 modelos analizados se infirió que el MFM de tres factores (IN, HI e IM) y cuatro clases, una mayoritaria de puntación baja (no afectados) y otra minoritaria de puntuación alta (afectados), junto con dos categorías intermedias muy similares, mostraba el mejor ajuste. Conclusiones: Los MFM mostraron que el TDAH variaría a lo largo de un continuo de gravedad, dentro de los síntomas del trastorno de leves, a moderados o graves, en lugar de existir como categorías discretas de diagnóstico.
Abstract: Background: Within the study of the structure of ADHD there is an ongoing debate as to whether phenotypic differences are due to differences in the severity of symptoms of inattention, hyperactivity, and impulsivity along an underlying continuum or whether the differences reflect are qualitatively distinct subtypes with unique etiologies. Objective: To analyze whether the behaviors of inattention, hyperactivity and impulsivity in children reflect qualitatively different presentations within ADHD, variations along a single continuum of severity or different levels of severity within the representations. Method: A study was carried out through confirmatory factor analysis (CFA), latent class analysis (LCA) and factor mixture models (FMM) of the ADHD phenotype according to the data collected through the Child and Adolescent Behavior Inventory (CABI) of 632 participants (M = 10.46 years; SD = 2.35) from the city of Talca (Chile) in general population. Results: For the 16 models analyzed, it was inferred that the MFM of three factors (IN, HI and IM) and four classes, a majority with a low score (unaffected) and a minority with a high score (affected), with two very similar intermediate categories, showed the best fit. Conclusions: The FMM showed that ADHD would vary along a continuum of severity, within symptoms of the disorder from mild, to moderate, or severe, rather than existing as discrete diagnostic categories.
Subject(s)
Humans , Male , Female , Child , Adolescent , Surveys and QuestionnairesABSTRACT
Abstract The alternative model of personality disorders introduced in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders provides a diagnostic system that is expected to correspond to the well-known categorical approach of personality disorder diagnoses. The current study aims to improve knowledge about the relationship between pathological personality traits and their corresponding personality types. A Brazilian sample of 1,162 people took part in this study. The results point to some level of continuity between the two models when the variables were treated as dimensional. Contrariwise, there is a lack of strong scientific evidence to justify the maintenance of the categorical approach. We recommend the exclusion of the categorical approach from personality disorder diagnosis systems.
Resumo O modelo alternativo de transtornos da personalidade introduzido na quinta edição do Manual Diagnóstico e Estatístico de Transtornos Mentais oferece um sistema diagnóstico que supostamente deve corresponder ao bem conhecido modelo de diagnóstico categórico dos transtornos da personalidade. O presente estudo tem por objetivo incrementar os conhecimentos sobre a relação entre os traços de personalidade e seus correspondentes tipos de personalidade. Uma amostra brasileira de 1.162 pessoas participou deste estudo. Os resultados indicaram algum nível de continuidade entre os dois modelos quando as variáveis foram consideradas dimensionais. Por outro lado, existe uma falta de evidência científica que justifique a manutenção da abordagem categórica. Recomenda-se a exclusão da abordagem categórica de sistemas diagnósticos de transtornos da personalidade.