53 research outputs found
Fungos micorrízicos arbusculares em solos da Reserva Biológica Municipal Serra dos Toledos, Itajubá/MG
The City Biological Reserve of ‘Serra dos Toledos’ is an important remaining tropical rain forest in south Minas Gerais statewhich has high biodiversity and water resources. Studies related to soil quality are needed in the reserve management plans, which aim to maintain or to improve the environmental sustainability of these areas. Thus, the purpose of this work was to evaluate the inoculum potential of arbuscular mycorrhizal fungi (AM) in samples of typical soil of that reserve. The quantification of propagules of this microbial group that establishes mutualistic symbiosis with most plant species, it is important for assessing the soil quality of the reserve Three areas inside and one outside the Reserve were set to study, where soil samples were removed at depth 0 to 10 cm, in two seasons, winter 2008 and summer 2009. The samples were sent to the Laboratory of Microbiology of the University of ‘Itajubá’ for quantification of the following microbiological attributes related to AM fungi: lengths of total and active extra-radical mycelium by the method of induced fluorescence with fluorescein diacetate, density and phenotypic diversity (morphotypes) of spores, percentage and intensity of root colonization. The average results were compared by Duncan 5% and subjected to multivariate analysis. The results showed that the potential for MA fungal inoculum had a higher effect of areas in relation to the studied periods, with greater length of active and total extra-radical mycelium, a higher proportion of active mycelium in relation to the total and a greater diversity of spores in soil from the City Biological Reserve of ‘Serra dos Toledos’, compared to the outside soil under pasture. The inoculum potential is not directly related to the soil fertility, where that outside the reserve, pasture, despite the best fertility were found smaller values of mycelium and diversity of MA fungal spores. A Reserva Biológica Municipal Serra dos Toledos é um importante remanescente de Mata Atlântica no sul de Minas Gerais, com elevada biodiversidade e riqueza em recursos hídricos. Estudos relacionados à qualidade de solos são necessários em planos de manejo de reservas, os quais objetivam manter ou melhorar a sustentabilidade ambiental dessas áreas. Assim, o objetivo do presente trabalho foi avaliar o potencial de inóculo de fungos micorrízicos arbusculares (MAs) em amostras de solo características desta Reserva. A quantificação de propágulos desse grupo de micro-organismos, que estabelecem simbiose mutualística com a maioria das espécies vegetais é importante para a avaliação da qualidade de solos da Reserva. Foram definidas três áreas internas e uma externa à Reserva, retirando-se amostras de solo na profundidade de 0 a 10 cm, em duas épocas, inverno de 2008 e verão de 2009. As amostras foram encaminhadas ao Laboratório de Microbiologia da Universidade Federal de Itajubá para quantificação dos seguintes atributos microbiológicos relacionados aos fungos MAs: comprimentos de micélio extrarradicular ativo e total pelo método da fluorescência induzida com diacetato de fluoresceína, densidade e diversidade fenotípica (morfotipos) de esporos, porcentagem e intensidade de colonização radicular. As médias dos resultados foram comparadas por Duncan 5% e submetidas à análise de multivariada. Os resultados mostraram que o potencial de inóculo de fungos MAs apresentou maior efeito das áreas que das épocas estudadas, sendo maior comprimento de micélio extrarradicular ativo e total, maior proporção de micélio ativo em relação ao total e maior diversidade de esporos obtidos nos solos dentro da Reserva Biológica Municipal Serra dos Toledos, em relação ao solo externo à mesma, sob pastagem. O potencial de inóculo não está diretamente relacionado à fertilidade do solo, ou seja, no solo externo à Reserva, sob pastagem, apesar da melhor fertilidade, foram encontrados os menores valores de micélio e diversidade de esporos de fungos MAs
Not understanding others. The RdoC approach to Theory of mind and empathy deficits in Schizophrenia, Borderline Personality Disorder and Mood Disorders
The Research Domani Criteria framework (RdoC) encourages research on specific impairments present across traditional nosological categories and suggests a list of biological and behavioral measures for assessing them. After a description of RdoC, in this article we focus on impairments of the ability of understanding others, specifically in Theory of Mind and empathy. We illustrate recent evidence on brain anomalies correlating with these deficits in Schizophrenia, Addiction Disorders and Mood Disorders populations. In the last section, we zoom out and consider this kind of research vis-à-vis the objection of being reductionistic that is, in favoring mechanistic accounts of mental disorders. We argue that metaphysical reductionism and explanatory reductionism are not conceptually entailed by the RdoC framework
Relationship between low levels of circulating TRAIL and atheromatosis progression in patients with chronic kidney disease.
Background:
Chronic kidney disease (CKD) patients experience a high risk of cardiovascular disease (CV); however, the factors involved in CV-related morbidity and mortality in these patients have not been fully defined. Tumor necrosis factor related apoptosis-inducing ligand (TRAIL) is a cytokine, which exhibits pleiotropic activities on endothelial, vascular smooth muscle and inflammatory cells, with relevant effects on atheromatous plaque formation. On this basis, the present study aims to investigate the role of TRAIL in atheromatosis progression in CKD patients.
Methods:
Circulating TRAIL levels were measured in 378 CKD patients belonging to the Spanish National Observatory of Atherosclerosis in Nephrology (NEFRONA) study. All patients were free of previous CV events. Carotid and femoral B-mode ultrasound was performed to detect the presence of plaque at baseline and after 24 months of follow-up.
Results:
The lowest levels of TRAIL at baseline were significantly (p<0.05) associated with the appearance, after 24 months of follow-up, of at least two new atheromatous plaques in all territories and of one new plaque in the carotid artery, even after adjusting for CV risk factors. In addition, the patients with low levels of TRAIL at baseline were characterized by the presence of at least one hypoechoic plaque in the carotid artery. This association was significant (p<0.05) even after adjusting for CKD stage.
Conclusions:
Overall, the results of our study suggest TRAIL as an assertable independent prognostic biomarker for atheromatosis plaque formation in CKD patients. This observation further supports the potential role of TRAIL for the prevention/treatment of CV disease.The NEFRONA study was funded by a research grant from Abbvie and the Spanish government RETIC (RD16/0009/0011) and FISPI16/01354. MVA is the recipient of the Italian Ministry of Health grant No. GR-2013-0 2358192.
SG is the recipient of the "Associazione Italiana per la Ricerca sul Cancro, AIRC" fellowship, No. 18055.
Moreover, the authors would like to thank Fondazione Dott. Carlo Fornasini (Poggio Renatico, Ferrara, Italy). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
Diagnosis of bipolar disorders and body mass index predict clustering based on similarities in cortical thickness-ENIGMA study in 2436 individuals
AIMS: Rates of obesity have reached epidemic proportions, especially among people with psychiatric disorders. While the effects of obesity on the brain are of major interest in medicine, they remain markedly under-researched in psychiatry. METHODS: We obtained body mass index (BMI) and magnetic resonance imaging-derived regional cortical thickness, surface area from 836 bipolar disorders (BD) and 1600 control individuals from 14 sites within the ENIGMA-BD Working Group. We identified regionally specific profiles of cortical thickness using K-means clustering and studied clinical characteristics associated with individual cortical profiles. RESULTS: We detected two clusters based on similarities among participants in cortical thickness. The lower thickness cluster (46.8% of the sample) showed thinner cortex, especially in the frontal and temporal lobes and was associated with diagnosis of BD, higher BMI, and older age. BD individuals in the low thickness cluster were more likely to have the diagnosis of bipolar disorder I and less likely to be treated with lithium. In contrast, clustering based on similarities in the cortical surface area was unrelated to BD or BMI and only tracked age and sex. CONCLUSIONS: We provide evidence that both BD and obesity are associated with similar alterations in cortical thickness, but not surface area. The fact that obesity increased the chance of having low cortical thickness could explain differences in cortical measures among people with BD. The thinner cortex in individuals with higher BMI, which was additive and similar to the BD-associated alterations, may suggest that treating obesity could lower the extent of cortical thinning in BD
DenseNet and Support Vector Machine classifications of major depressive disorder using vertex-wise cortical features
Major depressive disorder (MDD) is a complex psychiatric disorder that
affects the lives of hundreds of millions of individuals around the globe. Even
today, researchers debate if morphological alterations in the brain are linked
to MDD, likely due to the heterogeneity of this disorder. The application of
deep learning tools to neuroimaging data, capable of capturing complex
non-linear patterns, has the potential to provide diagnostic and predictive
biomarkers for MDD. However, previous attempts to demarcate MDD patients and
healthy controls (HC) based on segmented cortical features via linear machine
learning approaches have reported low accuracies. In this study, we used
globally representative data from the ENIGMA-MDD working group containing an
extensive sample of people with MDD (N=2,772) and HC (N=4,240), which allows a
comprehensive analysis with generalizable results. Based on the hypothesis that
integration of vertex-wise cortical features can improve classification
performance, we evaluated the classification of a DenseNet and a Support Vector
Machine (SVM), with the expectation that the former would outperform the
latter. As we analyzed a multi-site sample, we additionally applied the ComBat
harmonization tool to remove potential nuisance effects of site. We found that
both classifiers exhibited close to chance performance (balanced accuracy
DenseNet: 51%; SVM: 53%), when estimated on unseen sites. Slightly higher
classification performance (balanced accuracy DenseNet: 58%; SVM: 55%) was
found when the cross-validation folds contained subjects from all sites,
indicating site effect. In conclusion, the integration of vertex-wise
morphometric features and the use of the non-linear classifier did not lead to
the differentiability between MDD and HC. Our results support the notion that
MDD classification on this combination of features and classifiers is
unfeasible
In vivo hippocampal subfield volumes in bipolar disorder—A mega-analysis from The Enhancing Neuro Imaging Genetics through Meta-Analysis Bipolar Disorder Working Group
The hippocampus consists of anatomically and functionally distinct subfields that may be differentially involved in the pathophysiology of bipolar disorder (BD). Here we, the Enhancing NeuroImaging Genetics through Meta‐Analysis Bipolar Disorder workinggroup, study hippocampal subfield volumetry in BD. T1‐weighted magnetic resonance imaging scans from 4,698 individuals (BD = 1,472, healthy controls [HC] = 3,226) from 23 sites worldwide were processed with FreeSurfer. We used linear mixed‐effects models and mega‐analysis to investigate differences in hippocampal subfield volumes between BD and HC, followed by analyses of clinical characteristics and medication use. BD showed significantly smaller volumes of the whole hippocampus (Cohen's d = −0.20), cornu ammonis (CA)1 (d = −0.18), CA2/3 (d = −0.11), CA4 (d = −0.19), molecular layer (d = −0.21), granule cell layer of dentate gyrus (d = −0.21), hippocampal tail (d = −0.10), subiculum (d = −0.15), presubiculum (d = −0.18), and hippocampal amygdala transition area (d = −0.17) compared to HC. Lithium users did not show volume differences compared to HC, while non‐users did. Antipsychotics or antiepileptic use was associated with smaller volumes. In this largest study of hippocampal subfields in BD to date, we show widespread reductions in nine of 12 subfields studied. The associations were modulated by medication use and specifically the lack of differences between lithium users and HC supports a possible protective role of lithium in BD
Multi-site benchmark classification of major depressive disorder using machine learning on cortical and subcortical measures
Machine learning (ML) techniques have gained popularity in the neuroimaging field due to their potential for classifying neuropsychiatric disorders. However, the diagnostic predictive power of the existing algorithms has been limited by small sample sizes, lack of representativeness, data leakage, and/or overfitting. Here, we overcome these limitations with the largest multi-site sample size to date (N = 5365) to provide a generalizable ML classification benchmark of major depressive disorder (MDD) using shallow linear and non-linear models. Leveraging brain measures from standardized ENIGMA analysis pipelines in FreeSurfer, we were able to classify MDD versus healthy controls (HC) with a balanced accuracy of around 62%. But after harmonizing the data, e.g., using ComBat, the balanced accuracy dropped to approximately 52%. Accuracy results close to random chance levels were also observed in stratified groups according to age of onset, antidepressant use, number of episodes and sex. Future studies incorporating higher dimensional brain imaging/phenotype features, and/or using more advanced machine and deep learning methods may yield more encouraging prospects
Widespread white matter microstructural abnormalities in bipolar disorder: evidence from mega- and meta-analyses across 3033 individuals
Fronto-limbic white matter (WM) abnormalities are assumed to lie at the heart of the pathophysiology of bipolar disorder (BD);
however, diffusion tensor imaging (DTI) studies have reported heterogeneous results and it is not clear how the clinical
heterogeneity is related to the observed differences. This study aimed to identify WM abnormalities that differentiate patients with
BD from healthy controls (HC) in the largest DTI dataset of patients with BD to date, collected via the ENIGMA network. We gathered
individual tensor-derived regional metrics from 26 cohorts leading to a sample size of N = 3033 (1482 BD and 1551 HC). Mean
fractional anisotropy (FA) from 43 regions of interest (ROI) and average whole-brain FA were entered into univariate mega- and
meta-analyses to differentiate patients with BD from HC. Mega-analysis revealed significantly lower FA in patients with BD
compared with HC in 29 regions, with the highest effect sizes observed within the corpus callosum (R2 = 0.041, Pcorr < 0.001) and
cingulum (right: R2 = 0.041, left: R2 = 0.040, Pcorr < 0.001). Lithium medication, later onset and short disease duration were related to
higher FA along multiple ROIs. Results of the meta-analysis showed similar effects. We demonstrated widespread WM abnormalities
in BD and highlighted that altered WM connectivity within the corpus callosum and the cingulum are strongly associated with BD.
These brain abnormalities could represent a biomarker for use in the diagnosis of BD. Interactive three-dimensional visualization of the results is available at www.enigma-viewer.org
ARBUSCULAR MICORRHIZAL FUNGI IN SOILS FROM MUNICIPAL BIOLOGICAL RESERVE SERRA DOS TOLEDOS, ITAJUB\uc1/MG
A Reserva Biol\uf3gica Municipal Serra dos Toledos \ue9 um
importante remanescente de Mata Atl\ue2ntica no sul de Minas Gerais,
com elevada biodiversidade e riqueza em recursos h\ueddricos. Estudos
relacionados \ue0 qualidade de solos s\ue3o necess\ue1rios em
planos de manejo de reservas, os quais objetivam manter ou melhorar a
sustentabilidade ambiental dessas \ue1reas. Assim, o objetivo do
presente trabalho foi avaliar o potencial de in\uf3culo de fungos
micorr\uedzicos arbusculares (MAs) em amostras de solo
caracter\uedsticas desta Reserva. A quantifica\ue7\ue3o de
prop\ue1gulos desse grupo de micro-organismos, que estabelecem
simbiose mutual\uedstica com a maioria das esp\ue9cies vegetais
\ue9 importante para a avalia\ue7\ue3o da qualidade de solos da
Reserva. Foram definidas tr\ueas \ue1reas internas e uma externa
\ue0 Reserva, retirando-se amostras de solo na profundidade de 0 a 10
cm, em duas \ue9pocas, inverno de 2008 e ver\ue3o de 2009. As
amostras foram encaminhadas ao Laborat\uf3rio de Microbiologia da
Universidade Federal de Itajub\ue1 para quantifica\ue7\ue3o dos
seguintes atributos microbiol\uf3gicos relacionados aos fungos MAs:
comprimentos de mic\ue9lio extrarradicular ativo e total pelo
m\ue9todo da fluoresc\ueancia induzida com diacetato de
fluoresce\uedna, densidade e diversidade fenot\uedpica (morfotipos)
de esporos, porcentagem e intensidade de coloniza\ue7\ue3o
radicular. As m\ue9dias dos resultados foram comparadas por Duncan 5%
e submetidas \ue0 an\ue1lise de multivariada. Os resultados
mostraram que o potencial de in\uf3culo de fungos MAs apresentou
maior efeito das \ue1reas que das \ue9pocas estudadas, sendo maior
comprimento de mic\ue9lio extrarradicular ativo e total, maior
propor\ue7\ue3o de mic\ue9lio ativo em rela\ue7\ue3o ao total
e maior diversidade de esporos obtidos nos solos dentro da Reserva
Biol\uf3gica Municipal Serra dos Toledos, em rela\ue7\ue3o ao
solo externo \ue0 mesma, sob pastagem. O potencial de in\uf3culo
n\ue3o est\ue1 diretamente relacionado \ue0 fertilidade do solo,
ou seja, no solo externo \ue0 Reserva, sob pastagem, apesar da melhor
fertilidade, foram encontrados os menores valores de mic\ue9lio e
diversidade de esporos de fungos MAs.The City Biological Reserve of 'Serra dos Toledos' is an important
remaining tropical rain forest in south Minas Gerais statewhich has
high biodiversity and water resources. Studies related to soil quality
are needed in the reserve management plans, which aim to maintain or to
improve the environmental sustainability of these areas. Thus, the
purpose of this work was to evaluate the inoculum potential of
arbuscular mycorrhizal fungi (AM) in samples of typical soil of that
reserve. The quantifcation of propagules of this microbial group that
establishes mutualistic symbiosis with most plant species, it is
important for assessing the soil quality of the reserve. Three areas
inside and one outside the Reserve were set to study, where soil
samples were removed at depth 0 to 10 cm, in two seasons, winter 2008
and summer 2009. The samples were sent to the Laboratory of
Microbiology of the University of 'Itajub\ue1' for quantification of
the following microbiological attributes related to AM fungi: lengths
of total and active extra-radical mycelium by the method of induced
fluorescence with fluorescein diacetate, density and phenotypic
diversity (morphotypes) of spores, percentage and intensity of root
colonization. The average results were compared by Duncan 5% and
subjected to multivariate analysis. The results showed that the
potential for MA fungal inoculum had a higher effect of areas in
relation to the studied periods, with greater length of active and
total extra-radical mycelium, a higher proportion of active mycelium in
relation to the total and a greater diversity of spores in soil from
the City Biological Reserve of \u2018Serra dos Toledos\u2019,
compared to the outside soil under pasture. The inoculum potential is
not directly related to the soil fertility, where that outside the
reserve, pasture, despite the best fertility were found smaller values
of mycelium and diversity of MA fungal spores
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