Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 131
Filtrar
Mais filtros

Tipo de documento
Intervalo de ano de publicação
1.
An Acad Bras Cienc ; 96(1): e20230005, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38511741

RESUMO

Large meteorite impacts release kinetic energy that induces rock deformation, high temperatures and fluid circulation during the cratering process. To understand the correlation between rock deformation and fluid circulation, it is relevant to investigate post-impact hydrothermal flux and its relation to the local geology. The Cerro do Jarau impact structure is a ~13.5 km diameter impact structure located in southern Brazil and formed on Cretaceous continental flood basalts of the Serra Geral Formation and underlying sedimentary strata. This study collected ground gamma-ray data over the structure and produced K, eTh and eU concentrations, eTh/K ratio and F-factor maps to characterize it in terms of its radiometric signatures and their respective spatial distribution. A general decrease in the concentration of the three elements was observed from the outer-rim towards the center of the crater. The central area is defined by very low radiometric values, with relatively high K values, thus indicating the occurrence of K-bearing rocks. Numerical simulations using the HYDROTHERM 3 code showed the fluid circulation pattern over the impact structure. Data interpretation resulted in a scenery consistent with potential fluid remobilization within the impact structure related to hydrothermal processes in the late stages of the crater formation process.

2.
An Acad Bras Cienc ; 95(suppl 2): e20230365, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37909611

RESUMO

Obesity and depression, disorders associated with inflammation, have high incidences in women. Understanding the derangements present in the initial phase of obesity may point to factors that could help avoiding disease aggravation. The present study aimed at investigating the effects of a 6-months interdisciplinary therapy for weight loss in women with grade I obesity. Before and after the therapy, 37 middle-aged women donated blood and responded to questionnaires for depression and anxiety symptoms. Inflammatory parameters were evaluated in serum and a preliminary screening of the plasma proteome was performed. The therapy decreased anthropometric, psychological scores, and serum levels of inflammatory parameters. Depression and anxiety scores correlated positively with some inflammatory parameters. The proteomic analysis showed changes in proteins related to cholesterol metabolism and inflammatory response. Interdisciplinary therapy improves anthropometric and inflammatory statuses and ameliorating psychological symptoms. The decrease of MCP-1 levels after interdisciplinary therapy has not been reported so far, at the best of our knowledge. The present demonstration of positive associations of inflammatory markers and psychological scores indicate that these mediators may be useful to monitor psychological status in obesity. The present proteome data, although preliminary, pointed to plasma alterations indicative of improvement of inflammation after interdisciplinary therapy.


Assuntos
Proteoma , Proteômica , Pessoa de Meia-Idade , Humanos , Feminino , Obesidade , Inflamação/terapia , Inflamação/complicações , Estilo de Vida
3.
J Toxicol Environ Health A ; 85(8): 336-352, 2022 04 18.
Artigo em Inglês | MEDLINE | ID: mdl-34903147

RESUMO

Medicinal plants have always been used for therapeutic purposes; however, some plants may contain toxic and mutagenic substances. The aim of this study was to assess the cytotoxic, genotoxic, mutagenic, antioxidant, antigenotoxic, and antimutagenic effects of the bark ethanolic extract of Spondias purpurea L. using male and female Swiss albino mice. To determine the protective effects of the extract, benzo[a]pyrene (B[a]P) and cyclophosphamide (CP) were selected as cell damage inducers. The extract was examined at doses of 500, 1000, or 1500 mg/kg body weight (BW)via gavage alone or concomitant with B[a]P or CP. Oxidative stress was measured by quantification of blood catalase activity (CAT), reduced glutathione (GSH) levels in total blood, liver, and kidney, and concentrations of malondiadehyde (MDA) in liver and kidney. Genotoxicity and antigenotoxicity were evaluated by the comet assay using peripheral blood. Cytotoxicity, mutagenicity, and antimutagenicity were determined utilizing the micronucleus test in bone marrow and peripheral blood. The S. purpurea L extract increased CAT activity and GSH levels accompanied by a decrease in MDA levels after treatment with B[a]P and CP. No genotoxic, cytotoxic, or mutagenic effects were found in mice exposed only to the extract. These results indicate that the extract of S. purpurea exhibited protective effects against oxidative and DNA damage induced by B[a]P and CP.


Assuntos
Anacardiaceae , Antimutagênicos , Animais , Antimutagênicos/farmacologia , Antioxidantes/farmacologia , Ciclofosfamida/toxicidade , Dano ao DNA , Feminino , Masculino , Camundongos , Testes para Micronúcleos , Mutagênicos/toxicidade , Casca de Planta , Extratos Vegetais/farmacologia
4.
An Acad Bras Cienc ; 94(3): e20210182, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35857958

RESUMO

We present the analysis of airborne and ground gamma-ray spectrometry signatures of the Araguainha impact structure, located in central Brazil, the largest impact structure in South America with ~ 40 km diameter. The airborne data are total gamma-ray counts per second collected along flight lines spaced 1 km apart. The ground gamma-ray data are concentrations of potassium, uranium, and thorium isotopes calculated from radiations measured in three individual channels. The objectives are to distinguish lithologies within the structure, which have naturally distinctive radiogenic signatures, and identify potential post-impact hydrothermal alteration zones, as indicated by high K concentrations. Based on results obtained by numerical modeling of the crater formation, we infer the locations of potential occurrences of target rocks that may have undergone hydrothermal alteration as a result of the impact. The deviations from the background potassium concentration show significant anomalous K values at the center and in the northwestern crater rim, where high concentrations of U are also observed. The numerical model shows that ideal temperature conditions for hydrothermal fluid circulation were attained right after pos-impact gravitational stabilization.


Assuntos
Espectrometria gama , Urânio , Brasil , Raios gama , Potássio/análise , Urânio/análise
5.
Sensors (Basel) ; 22(23)2022 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-36501807

RESUMO

In a smart grid communication network, positioning key devices (routers and gateways) is an NP-Hard problem as the number of candidate topologies grows exponentially according to the number of poles and smart meters. The different terrain profiles impose distinct communication losses between a smart meter and a key device position. Additionally, the communication topology must consider the position of previously installed distribution automation devices (DAs) to support the power grid remote operation. We introduce the heuristic method AIDA (AI-driven AMI network planning with DA-based information and a link-specific propagation model) to evaluate the connectivity condition between the meters and key devices. It also uses the link-received power calculated for the edges of a Minimum Spanning Tree to propose a simplified multihop analysis. The AIDA method proposes a balance between complexity and efficiency, eliminating the need for empirical terrain characterization. Using a spanning tree to characterize the connectivity topology between meters and routers, we suggest a heuristic approach capable of alleviating complexity and facilitating scalability. In our research, the interest is in proposing a method for positioning communication devices that presents a good trade-off between network coverage and the number of communication devices. The existing literature explores the theme by presenting different techniques for ideal device placement. Still rare are the references that meticulously explore real large-scale scenarios or the communication feasibility between meters and key devices, considering the detailed topography between the devices. The main contributions of this work include: (1) The presentation of an efficient AMI planning method with a large-scale focus; (2) The use of a propagation model that does not depend on an empirical terrain classification; and (3) The use of a heuristic approach based on a spanning tree, capable of evaluating a smaller number of connections and, even so, proposing a topology that uses fewer router and gateway positions compared to an approach that makes general terrain classification. Experiments in four real large-scale scenarios, totaling over 230,000 smart meters, demonstrate that AIDA can efficiently provide high-quality connectivity demanding a reduced number of devices. Additional experiments comparing AIDA's detailed terrain-based propagation model to the Erceg-SUI Path Loss model suggest that AIDA can reach the smart meter's coverage with a fewer router positions.


Assuntos
Eletricidade
6.
Ecol Food Nutr ; 61(6): 651-668, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36031880

RESUMO

This article analyzes factors influencing the adoption of kitchen gardens and food and nutrition security implications of kitchen gardens on farming households. For this, the Per Capita Kilocalorie Intake (PKCI) and Food Consumption Score (FCS) were applied as food and nutrition security indicators. This paper is based on cross-sectional data that include a sample of 825 households from two districts in Tanzania. Endogenous Switching Regression is employed to determine factors influencing the adoption of a kitchen garden and its impact on food and nutrition security of the involved farming households. The results of the analysis indicate that the adoption of a kitchen garden increased with the family size (adult equivalent), credit use, access to information, districts (location), and the usage of other water sources for agriculture in addition to rainfed. It decreased with total land size and TLU. While the adoption of a kitchen garden significantly increased adopters' FCS by 1.45 or 2.96% and non-adopters' FCS by 1.26 or 2.69%. In contrast, the adoption of a kitchen garden significantly reduced non-adopters' PKCI by 101.18 or 3.92% but it does not have significant impact for adopters. Therefore, policymakers and development organizations should further promote and scale-up the kitchen garden intervention in order to use it as a tool to enhance the household's food and nutrition security.


Assuntos
Agricultura , Jardins , Adulto , Humanos , Estudos Transversais , Tanzânia , Agricultura/métodos , Características da Família , Abastecimento de Alimentos
7.
AIDS Care ; 33(10): 1321-1328, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-32715739

RESUMO

This cross-sectional study compared the Oral-Health-Related Quality of Life (OHRQoL) in HIV negative patients (Group 1, n=129, mean age: 39.9 ± 15.6, 75 females) and HIV+ patients (Group 2, n=670, mean age: 43.2 ± 9.8, 246 females) from the same socio-economic environment using the OHIP-49 questionnaire. OHIP total score were determined by simple summing. A multiple linear regression model was carried out to predict OHIP scores in which HIV+ patients experienced a significantly (p<0.001) worst OHRQoL for total and every dimension. A general linear model was used for estimating the means in the two groups adjusted for covariates included in the previous model. Adjusted means for subscale and total OHIP scores were significantly higher for Group 2 (61.6 ± 6.26 vs. 119.8 ± 3.31) with a large effect size (0.94). HIV+ infection, decayed teeth, prosthodontic and surgical needs, care index, drug use, employment and age presented an independent effect on questionnaire scores. This study shows that HIV+ infection has an independent and negative impact on the OHRQoL while care index presents a positive impact. Additional factors like high decayed teeth, prosthodontic treatment needs and drug use are independently associated with total OHIP scores, presenting a negative effect on OHRQoL.


Assuntos
Infecções por HIV , HIV-1 , Adulto , Estudos Transversais , Feminino , Humanos , Pessoa de Meia-Idade , Saúde Bucal , Qualidade de Vida , Inquéritos e Questionários , Adulto Jovem
8.
Drug Chem Toxicol ; 44(1): 64-74, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30394117

RESUMO

The aim of this study was to assess the protective effects of oral and topical treatment with Bidens pilosa (BP) against carbon tetrachloride (CCl4)- induced toxicity. Fifty-six rats were divided into seven groups: A: CCl4 only; B: CCl4+oral BP; C: CCl4 and topical BP; D: CCl4+oral and topical BP; E: oral BP only; F: negative control; and G: positive control (cyclophosphamide). The animals were treated for 10 weeks. Blood samples were collected for tests of hepatic and renal function, and fragments of the liver, spleen, pancreas, kidney, and intestine were collected for histopathological analyses. Cells from the femoral bone marrow were used for a micronucleus test and 'comet assay'. Statistically significant differences were observed in the levels of gamma-glutamyl transpeptidase (GGT), albumin, urea and creatinine, hepatic inflammation, renal tubular lesion, and inflammation of the intestinal mucosa between the BP-treated groups and untreated group. The median number of micronuclei in group A was 4.00, in group G was 9.00 and in the other groups was 0.00. Group A had the lowest number of cells with a score of 0 and the greatest number with scores of 3 and 4, similar to the results obtained from group G using the 'comet assay'. Thus, BP effectively protected against the toxic effects of CCl4 on the liver, kidney, and intestine and exerted an antimutagenic effect on rats exposed to CCl4.


Assuntos
Anti-Inflamatórios/farmacologia , Antimutagênicos/farmacologia , Bidens , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Medicamentos de Ervas Chinesas/farmacologia , Nefropatias/prevenção & controle , Rim/efeitos dos fármacos , Fígado/efeitos dos fármacos , Animais , Tetracloreto de Carbono , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/patologia , Ensaio Cometa , Dano ao DNA , Modelos Animais de Doenças , Rim/metabolismo , Rim/patologia , Nefropatias/induzido quimicamente , Nefropatias/metabolismo , Nefropatias/patologia , Fígado/metabolismo , Fígado/patologia , Masculino , Micronúcleos com Defeito Cromossômico/induzido quimicamente , Micronúcleos com Defeito Cromossômico/efeitos dos fármacos , Testes para Micronúcleos , Ratos Wistar
9.
Horm Behav ; 125: 104839, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32800765

RESUMO

Body feminization, as part of gender affirmation process of transgender women, decreases the volume of their cortical and subcortical brain structures. In this work, we implement a rat model of adult male feminization which reproduces the results in the human brain and allows for the longitudinal investigation of the underlying structural and metabolic determinants in the brain of adult male rats undergoing feminization treatments. Structural MRI and Diffusion Tensor Imaging (DTI) were used to non-invasively monitor in vivo cortical brain volume and white matter microstructure over 30 days in adult male rats receiving estradiol (E2), estradiol plus cyproterone acetate (CA), an androgen receptor blocker and antigonadotropic agent (E2 + CA), or vehicle (control). Ex vivo cerebral metabolic profiles were assessed by 1H High Resolution Magic Angle Spinning NMR (1H HRMAS) at the end of the treatments in samples from brain regions dissected after focused microwave fixation (5 kW). We found that; a) Groups receiving E2 and E2 + CA showed a generalized bilateral decrease in cortical volume; b) the E2 + CA and, to a lesser extent, the E2 groups maintained fractional anisotropy values over the experiment while these values decreased in the control group; c) E2 treatment produced increases in the relative concentration of brain metabolites, including glutamate and glutamine and d) the glutamine relative concentration and fractional anisotropy were negatively correlated with total cortical volume. These results reveal, for the first time to our knowledge, that the volumetric decreases observed in trans women under cross-sex hormone treatment can be reproduced in a rat model. Estrogens are more potent drivers of brain changes in male rats than anti-androgen treatment.


Assuntos
Encéfalo/efeitos dos fármacos , Acetato de Ciproterona/farmacologia , Estradiol/farmacologia , Feminização , Metaboloma/efeitos dos fármacos , Antagonistas de Androgênios/farmacologia , Animais , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Encéfalo/patologia , Imagem de Tensor de Difusão , Feminino , Feminização/induzido quimicamente , Feminização/metabolismo , Feminização/patologia , Ácido Glutâmico/metabolismo , Hormônios Esteroides Gonadais/metabolismo , Imageamento por Ressonância Magnética , Masculino , Ratos , Ratos Wistar , Receptores Androgênicos/metabolismo , Transexualidade/induzido quimicamente , Transexualidade/diagnóstico por imagem , Transexualidade/metabolismo , Transexualidade/patologia
10.
Addict Biol ; 25(2): e12706, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-30623520

RESUMO

Relapse into drug use is a major problem faced by recovering addicts. In humans, an intensification of the desire for the drug induced by environmental cues-incubation of drug craving-has been observed. In rodents, this phenomenon has been modeled by studying drug seeking under extinction after different times of drug withdrawal (or using a natural reinforcer). Although much progress has been made, an integrated approach simultaneously studying different drug classes and natural reward and examining different brain regions is lacking. Lewis rats were used to study the effects of cocaine, heroin, and sucrose seeking incubation on six key brain regions: the nucleus accumbens shell/core, central/basolateral amygdala, and dorsomedial/ventromedial prefrontal cortex. We analyzed PSD95 and gephyrin protein levels, gene expression of glutamatergic, GABAergic and endocannabinoid elements, and amino acid transmitter levels. The relationships between the areas studied were examined by Structural Equation Modelling. Pathways from medial prefrontal cortex and basolateral complex of the amygdala to central nucleus of the amygdala, but not to the nucleus accumbens, were identified as common elements involved in the incubation phenomenon for different substances. These results suggest a key role for the central nucleus of amygdala and its cortical and amygdalar afferences in the incubation phenomenon, and we suggest that by virtue of its regulatory effects on glutamatergic and GABAergic dynamics within amygdalar circuits, the endocannabinoid system might be a potential target to develop medications that are effective in the context of relapse.


Assuntos
Núcleo Central da Amígdala/efeitos dos fármacos , Transtornos Relacionados ao Uso de Cocaína/prevenção & controle , Transtornos Relacionados ao Uso de Cocaína/fisiopatologia , Transtornos Relacionados ao Uso de Opioides/fisiopatologia , Transtornos Relacionados ao Uso de Opioides/psicologia , Reforço Psicológico , Analgésicos Opioides/farmacologia , Animais , Comportamento Animal/efeitos dos fármacos , Núcleo Central da Amígdala/fisiopatologia , Cocaína/farmacologia , Modelos Animais de Doenças , Inibidores da Captação de Dopamina/farmacologia , Heroína/farmacologia , Masculino , Ratos , Ratos Endogâmicos Lew , Autoadministração , Sacarose/farmacologia
11.
Foodborne Pathog Dis ; 17(1): 44-51, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31532261

RESUMO

Staphylococcus aureus is a Gram-positive bacterium that causes intramammary infections and bulk tank milk (BTM) contamination in dairy operations around the world in spite of on-farm application of preventive measures. The study was conducted on a 30-cow dairy farm in the Ñuble Region of Chile. For BTM culture and somatic cell count (SCC) analysis, three consecutive BTM samples were collected. Samples for bacterial culture (n = 16) were collected from macroscopic adherence on previously washed, sanitized, and dry milking equipment surfaces in direct contact with milk during milking or cooling. A total of 48 S. aureus isolates from BTM, milking equipment, and cows' quarters with intramammary infections were analyzed by pulsed-field gel electrophoresis (PFGE). Selected milking equipment pieces were removed for biofilm visualization using scanning electron microscopy (SEM). S. aureus was isolated from all three BTM samples; the average SCC for the three BTM samples was 1,429,333 cells/mL. Fourteen of the 16 samples of milking equipment (87.5%) were culture positive for S. aureus. Biofilms were visualized by SEM in all four removed milking equipment pieces. Microorganisms observed by SEM in those biofilms were mainly coccus-shaped bacteria, and microbiological culture of these biofilms yielded viable S. aureus isolates in all samples. All pulsotypes observed among S. aureus isolates from BTM were indistinguishable from those in milking equipment surfaces. All PFGE pulsotypes observed among S. aureus isolates from biofilms on rubber liners were indistinguishable from isolates from intramammary infections in cows. Our findings suggest that milking equipment films may act as source of S. aureus contamination for BTM and cows during milking, thus compromising the microbiological quality of milk used for manufacturing dairy products.


Assuntos
Criação de Animais Domésticos , Microbiologia de Alimentos , Glândulas Mamárias Animais/microbiologia , Mastite Bovina/prevenção & controle , Leite/microbiologia , Staphylococcus aureus/isolamento & purificação , Animais , Biofilmes , Bovinos , Chile , Indústria de Laticínios , Fazendas , Feminino , Leite/citologia , Staphylococcus aureus/fisiologia
12.
Horm Metab Res ; 51(6): 375-380, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31207658

RESUMO

Obesity is a chronic and multifactorial disease promoted by positive energy balance. The objective was to evaluate the effects of interdisciplinary therapy in the neuroendocrine control of food intake, inflammatory markers, and psychological aspects in obese women. Forty-seven obese women (43.32±5.82 years, 34.86±3.08 kg/m2), aged 30-50 years, participated in an interdisciplinary lifestyle change therapy, consisting of nutritional counseling, physical exercises, and psychological therapy for 36 weeks. After the long-term therapy, there was a decrease in body weight (Δ -5.36 kg), BMI (Δ -2.01 kg/m2), abdominal (Δ -9.09 cm), hip (Δ -5.03 cm), and thigh (Δ -5.07 cm) perimeters. There was also a significant improvement in body composition, with an increase in fat-free mass (Δ 1.60%) and reduction of body fat (Δ -3.74 kg). The therapy proposed also provided an improvement in depression scores (Δ -6.63), anxiety (Δ -4.07), body image (Δ -25.25), and binge eating (Δ -5.25). There was a significant reduction in serum levels of leptin (Δ -15.62 ng/ml). The interdisciplinary therapy was able to provide both, physical and psychological benefits in energy balance, which enables the use of this model as a feasible clinical strategy for the treatment of obesity.


Assuntos
Biomarcadores/análise , Dietoterapia , Terapia por Exercício , Inflamação/prevenção & controle , Obesidade/psicologia , Obesidade/terapia , Psicoterapia , Adulto , Composição Corporal , Índice de Massa Corporal , Feminino , Estilo de Vida Saudável , Humanos , Leptina , Pessoa de Meia-Idade , Equipe de Assistência ao Paciente , Redução de Peso
13.
Breast Cancer Res Treat ; 172(3): 637-646, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30159786

RESUMO

PURPOSE: Knowledge about the germline mutational spectrum among Brazilian with hereditary breast and ovarian cancer (HBOC) is limited. Only five studies have performed comprehensive BRCA sequencing, corresponding to 1041 individuals among a Brazilian population of over 207 million people. Herein we aimed to determine the clinical and molecular characteristics of Brazilian patients who underwent oncogenetic counseling and genetic testing of a panel of high-risk and moderate-risk genes from 2009 to 2017. METHODS: Massively parallel sequencing was applied in 157 individuals (132 breast cancer-affected and 25 breast cancer-unaffected individuals) selected according NCCN criteria for hereditary breast cancer. Analysis of mutation segregation in family members was performed by capillary bidirectional sequencing, clinical response after treament and survival analysis was estimated by Kaplan-Meier. RESULTS: Nineteen germline variants were identified,15 pathogenic and 4 VUS (Variants of Uncertain Significance) in 27 individuals (27/157; 17% P < 0.0001) distributed among 7 genes. Sixty-eight percent of patients (13/19) harbor mutation in BRCA genes and 32% (6/19) in moderate risk genes. This is the first study reporting ATR deleterious germline mutation in association with hereditary breast cancer. Cancer-affected patients with moderate- risk mutation present a more aggressive phenotype, with bilateral cancer (25% vs. 13%, P = 0.0305), high-grade tumors (79.2% vs. 46.3%, P = 0.0001) and triple-negative (50% vs. 22.4%, P < 0.0001). However, no difference in the 5 years overall survival was observed between BRCA and moderate risk groups. CONCLUSIONS: This work highlights the benefits of large-scale sequencing for oncogenetic counseling and extends our understanding about the genetics of hereditary breast cancer in the multi-ethnic Brazilian population.


Assuntos
Neoplasias da Mama/genética , Predisposição Genética para Doença , Mutação em Linhagem Germinativa , Proteínas Mutadas de Ataxia Telangiectasia/genética , Brasil , Neoplasias da Mama/etiologia , Neoplasias da Mama/mortalidade , Feminino , Genes BRCA1 , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Risco
14.
Plant Physiol ; 174(2): 823-842, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28507175

RESUMO

The asymmetric cell divisions necessary for stomatal lineage initiation and progression in Arabidopsis (Arabidopsis thaliana) require the function of the basic helix-loop-helix (bHLH) transcription factor SPEECHLESS (SPCH). Mutants lacking SPCH do not produce stomata or lineages. Here, we isolated a new spch-5 allele carrying a point mutation in the bHLH domain that displayed normal growth, but had an extremely low number of sometimes clustered stomata in the leaves, whereas the hypocotyls did not have any stomata. In vivo tracking of leaf epidermal cell divisions, combined with marker lines and genetic analysis, showed that the spch-5 leaf phenotype is dosage dependent and results from the decreased ability to initiate and amplify lineages, defects in asymmetric cell fate allocation, and misorientation of asymmetric division planes. Notably, application of brassinosteroids (BRs) partly rescued the stomatal leaf phenotype of spch-5 Transcriptomic analysis combining spch-5 with BR treatments revealed that the expression of a set of SPCH target genes was restored by BRs. Our results also show that BR-dependent stomata formation and expression of some, but not all, SPCH target genes require the integrity of the bHLH domain of SPCH.


Assuntos
Proteínas de Arabidopsis/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Brassinosteroides/metabolismo , Mutação , Estômatos de Plantas/fisiologia , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Arabidopsis/fisiologia , Proteínas de Arabidopsis/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Brassinosteroides/farmacologia , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Diferenciação Celular , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Regulação da Expressão Gênica de Plantas , Hipocótilo/citologia , Folhas de Planta/citologia , Folhas de Planta/genética , Estômatos de Plantas/citologia , Estômatos de Plantas/efeitos dos fármacos , Plantas Geneticamente Modificadas , Domínios Proteicos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
15.
J Neurosci ; 34(44): 14551-9, 2014 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-25355209

RESUMO

People with mild cognitive impairment (MCI) show a high risk to develop Alzheimer's disease (AD; Petersen et al., 2001). Nonetheless, there is a lack of studies about how functional connectivity patterns may distinguish between progressive (pMCI) and stable (sMCI) MCI patients. To examine whether there were differences in functional connectivity between groups, MEG eyes-closed recordings from 30 sMCI and 19 pMCI subjects were compared. The average conversion time of pMCI was 1 year, so they were considered as fast converters. To this end, functional connectivity in different frequency bands was assessed with phase locking value in source space. Then the significant differences between both groups were correlated with neuropsychological scores and entorhinal, parahippocampal, and hippocampal volumes. Both groups did not differ in age, gender, or educational level. pMCI patients obtained lower scores in episodic and semantic memory and also in executive functioning. At the structural level, there were no differences in hippocampal volume, although some were found in left entorhinal volume between both groups. Additionally, pMCI patients exhibit a higher synchronization in the alpha band between the right anterior cingulate and temporo-occipital regions than sMCI subjects. This hypersynchronization was inversely correlated with cognitive performance, both hippocampal volumes, and left entorhinal volume. The increase in phase synchronization between the right anterior cingulate and temporo-occipital areas may be predictive of conversion from MCI to AD.


Assuntos
Ritmo alfa/fisiologia , Córtex Cerebral/fisiopatologia , Disfunção Cognitiva/fisiopatologia , Idoso , Progressão da Doença , Feminino , Humanos , Magnetoencefalografia , Masculino , Testes Neuropsicológicos
16.
Liver Int ; 35(8): 1983-91, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25708133

RESUMO

BACKGROUND & AIMS: Relationship between gallstones and non-alcoholic fatty liver disease (NAFLD), and largely non-alcoholic steatohepatitis (NASH), is uncertain. AIM: To determine the prevalence, non-invasive fibrosis markers profile and risk factors for biopsy-proven NAFLD and NASH among patients with gallstones. METHODS: Anthropometric and laboratory evaluation, an abdominal ultrasound and a liver biopsy were performed to 215 consecutive patients with gallstones referred for cholecystectomy. RESULTS: Prevalence of NASH was 10.2% whereas that of simple steatosis (SS) was 41.4%. In the cohort of NAFLD patients, negative predictive values for advanced fibrosis of FIB-4 and NAFLD fibrosis score were 96 and 95% respectively. Gallstone patients with NASH had a higher mean homeostatic model assessment (HOMA) score than those with SS (P = 0.015). Noteworthy, NASH was 2.5-fold more frequent in patients with gallstones who had metabolic syndrome than in those who did not (P < 0.001). Fatty liver on ultrasound was observed in 90.9% of gallstone patients with NASH compared with 61.8% of those with SS (P = 0.044). Using multivariate logistic regression, increased HOMA score (OR, 3.47; 95% CI, 1.41-8.52; P = 0.007) and fatty liver on ultrasound (OR, 23.27; 95% CI, 4.15-130.55; P < 0.001) were the only factors independently associated with NASH. CONCLUSIONS: Prevalence of NASH among patients with gallstones is lower than estimated previously, but NASH is frequent particularly in those patients with concurrent metabolic syndrome. The combination of an increased HOMA score with fatty liver on ultrasound has a good accuracy for predicting NASH in patients with gallstones.


Assuntos
Cálculos Biliares/epidemiologia , Cálculos Biliares/patologia , Hepatopatia Gordurosa não Alcoólica/epidemiologia , Hepatopatia Gordurosa não Alcoólica/patologia , Adulto , Distribuição por Idade , Idoso , Análise de Variância , Biópsia por Agulha , Colecistectomia Laparoscópica , Estudos de Coortes , Feminino , Seguimentos , Cálculos Biliares/diagnóstico por imagem , Cálculos Biliares/cirurgia , Humanos , Imuno-Histoquímica , Testes de Função Hepática , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Hepatopatia Gordurosa não Alcoólica/diagnóstico por imagem , Prevalência , Estudos Prospectivos , Medição de Risco , Índice de Gravidade de Doença , Distribuição por Sexo , Resultado do Tratamento , Ultrassonografia
17.
Exp Appl Acarol ; 66(3): 415-26, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25910991

RESUMO

Studies on the seasonal variation of agricultural pest species are important for the establishment of integrated pest control programs. The seasonality of pest attacks on crops is affected by biotic and abiotic factors, for example, climate and natural enemies. Besides that, characteristics of the host plant, crop management, location and the pests' bioecology also affect this seasonality. The mites Polyphagotarsonemus latus (Prostigmata: Tarsonemidae) and Tetranychus bastosi (Prostigmata: Tetranychidae) are the most important pests in the cultivation of physic nut, Jatropha curcas (Euphorbiaceae). All parts of J. curcas can be used for a wide range of purposes. In addition many researchers have studied its potential for use as neat oil, as transesterified oil (biodiesel), or as a blend with diesel. However studies about physic nut pests have been little known. The objective of this study was to assess the seasonal variation of P. latus and T. bastosi in physic nut. This study was conducted at three sites in the state of Tocantins, Brazil. We monitored climatic elements and the densities of the two mite species and of their natural enemies for a period of 2 years. Attack by P. latus occurred during rainy seasons, when the photoperiod was short and the physic nut had new leaves. In contrast, attack by T. bastosi occurred during warmer seasons with longer photoperiods and stronger winds. Populations of both mites and their natural enemies were greater in sites with greater plant diversity adjacent to the plantations. The predators found in association with P. latus and T. bastosi were Euseius concordis (Acari: Phytoseiidae), spiders, Stethorus sp. (Coleoptera: Coccinellidae) and Chrysoperla sp. (Neuroptera: Chrysopidae).


Assuntos
Agricultura , Jatropha/crescimento & desenvolvimento , Ácaros/fisiologia , Estações do Ano , Animais , Brasil , Cadeia Alimentar , Insetos/fisiologia , Dinâmica Populacional , Especificidade da Espécie , Aranhas/fisiologia , Tetranychidae/fisiologia
18.
Environ Monit Assess ; 187(11): 707, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26502728

RESUMO

The effects of cage aquaculture on freshwater ecosystems are determined by multiple farming and environmental variables, and thus, the assessment of a wide range of abiotic and biotic variables enables better understanding of the impacts generated by this nutrient source. This study was carried out at Castanhão reservoir located in the State of Ceará, which is the largest Brazilian producer of Nile tilapia in cage systems, wherein about 8000 reservoirs provide a vast area to expand not only this important socio-economic but also pollution-prone activity. Nutrient mass budget, water quality monitoring, hydrodynamic characterization, and elemental/stable isotopic composition of end-member products were measured in cage aquaculture and other reservoir areas in order to determine the relative effects on reservoir conditions. Nutrient budgets showed that 34% of the artificial feed was lost to the water column but water quality monitoring and isotopic composition analysis suggested that the cages were not extensively impacting the water quality probably because of the physiographic and hydrodynamic features of the cage site.


Assuntos
Aquicultura , Poluentes da Água/análise , Brasil , Ecossistema , Monitoramento Ambiental , Alimentos , Água Doce , Nitrogênio/análise , Fósforo/análise , Qualidade da Água
19.
Plant J ; 75(5): 808-22, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23662679

RESUMO

Epidermal differentiation in Arabidopsis thaliana aerial organs involves stomatal lineage development. Lineages derive from meristemoids, which arise from asymmetric divisions of protodermal cells. Each meristemoid divides repeatedly in an inward spiral before it transits to a guard mother cell (GMC) that produces the stoma, leaving a trail of surrounding stomatal lineage ground cells (SLGCs) that eventually differentiate into endoreplicated pavement cells. MUTE is a bHLH transcription factor that is expressed in late meristemoids and drives their transition to GMCs. Loss-of-function mute mutants are stomata-less dwarf plants with arrested lineages, in which stunted putative SLGCs surround a halted meristemoid. We analysed MUTE functions using a chemically inducible system for mute-3 complementation based on conditional MUTE expression in its normal domain. Continuous induction from germination produced stomata-bearing, normal-sized plants with viable mute-3 seeds. In 2-week-old mute-3 cotyledons, meristemoids appeared to retain their identity and synchronously formed stomata in response to induced MUTE expression. However, arrested SLGCs were not complemented: many produced stomata, leading to stomatal clusters, and others remained unexpanded and diploid. In contrast, non-lineage pavement cells, which are under-endoreplicated in mute-3, expanded and increased their ploidy level upon induction, showing that the lack of response of SLGCs is specific to this arrested cell type. Leaf phenotypic mosaics include wild-type lineages and adjacent mute-3 lineages, whose meristemoids and putative SLGCs remained arrested, indicating that the role of MUTE in SLGC fate is strictly lineage-autonomous. These results show that timely MUTE expression is essential to prevent stomatal fate in SLGCs and to promote their differentiation as pavement cells.


Assuntos
Proteínas de Arabidopsis/fisiologia , Arabidopsis/crescimento & desenvolvimento , Fatores de Transcrição Hélice-Alça-Hélice Básicos/fisiologia , Diferenciação Celular/genética , Estômatos de Plantas/crescimento & desenvolvimento , Arabidopsis/citologia , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Estradiol/farmacologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Marcadores Genéticos , Fenótipo , Estômatos de Plantas/genética , Estômatos de Plantas/ultraestrutura , Ploidias
20.
Neuroimage ; 101: 765-77, 2014 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-25111472

RESUMO

Whole brain resting state connectivity is a promising biomarker that might help to obtain an early diagnosis in many neurological diseases, such as dementia. Inferring resting-state connectivity is often based on correlations, which are sensitive to indirect connections, leading to an inaccurate representation of the real backbone of the network. The precision matrix is a better representation for whole brain connectivity, as it considers only direct connections. The network structure can be estimated using the graphical lasso (GL), which achieves sparsity through l1-regularization on the precision matrix. In this paper, we propose a structural connectivity adaptive version of the GL, where weaker anatomical connections are represented as stronger penalties on the corresponding functional connections. We applied beamformer source reconstruction to the resting state MEG recordings of 81 subjects, where 29 were healthy controls, 22 were single-domain amnestic Mild Cognitive Impaired (MCI), and 30 were multiple-domain amnestic MCI. An atlas-based anatomical parcellation of 66 regions was obtained for each subject, and time series were assigned to each of the regions. The fiber densities between the regions, obtained with deterministic tractography from diffusion-weighted MRI, were used to define the anatomical connectivity. Precision matrices were obtained with the region specific time series in five different frequency bands. We compared our method with the traditional GL and a functional adaptive version of the GL, in terms of log-likelihood and classification accuracies between the three groups. We conclude that introducing an anatomical prior improves the expressivity of the model and, in most cases, leads to a better classification between groups.


Assuntos
Encéfalo/fisiologia , Disfunção Cognitiva/diagnóstico , Conectoma/métodos , Magnetoencefalografia/métodos , Processamento de Sinais Assistido por Computador , Idoso , Inteligência Artificial , Biomarcadores , Encéfalo/anatomia & histologia , Encéfalo/fisiopatologia , Imagem de Difusão por Ressonância Magnética , Feminino , Humanos , Masculino , Imagem Multimodal
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa