365 research outputs found
Equações para estimar factores de expansão de biomassa para as principais espécies florestais em Portugal
Para estimar a biomassa do povoamento, usualmente são utilizados dois métodos: aplicação de equações de biomassa ao nível da árvore e aplicação de factores de expansão de biomassa (BEF) constante, pela simples multiplicação destes valores pelo volume do povoamento. A utilização de factores de expansão de biomassa, em relação à determinação da biomassa com recurso a equações alométricas da árvore, tem a vantagem de ser aplicável em dados já processados e em modelos de crescimento de povoamento que não incluem o módulo de biomassa. Diversos estudos concluíram que o factor de expansão de biomassa não é constante ao longo do tempo, mas que depende do estado de desenvolvimento do povoamento. Neste estudo apresenta-se equações para estimar os factores de expansão de biomassa a partir de variáveis do povoamento facilmente obtidas com os dados de inventário florestal, para algumas espécies florestais, nomeadamente: pinheiro bravo, eucalipto, sobreiro, pinheiro manso e castanheiro. Os resultados da sua aplicação são comparados com os resultados obtidos com aplicação dos valores de BEF constantes publicados em Portugal e com aplicação das recentes equações alométricas para estimar o volume e a biomassa da árvore individual
Equações para estimar factores de expansão de biomassa para as principais espécies florestais em Portugal
Para estimar a biomassa do povoamento, usualmente são utilizados dois métodos: aplicação de equações de biomassa ao nível da árvore e aplicação de factores de expansão de biomassa (BEF) constante, pela simples multiplicação destes valores pelo volume do povoamento. A utilização de factores de expansão de biomassa, em relação à determinação da biomassa com recurso a equações alométricas da árvore, tem a vantagem de ser aplicável em dados já processados e em modelos de crescimento de povoamento que não incluem o módulo de biomassa. Diversos estudos concluíram que o factor de expansão de biomassa não é constante ao longo do tempo, mas que depende do estado de desenvolvimento do povoamento. Neste estudo apresenta-se equações para estimar os factores de expansão de biomassa a partir de variáveis do povoamento facilmente obtidas com os dados de inventário florestal, para algumas espécies florestais, nomeadamente: pinheiro bravo, eucalipto, sobreiro, pinheiro manso e castanheiro. Os resultados da sua aplicação são comparados com os resultados obtidos com aplicação dos valores de BEF constantes publicados em Portugal e com aplicação das recentes equações alométricas para estimar o volume e a biomassa da árvore individual
Assessment of project portfolio management on public research institutions: a case applied to agricultural research in Brazil.
Portfolio management can be a major tool for selecting projects where scarce public resources will be invested with the best returns for society. This study aimed to propose a model for diagnostic of project portfolio management (PPM) on public research institutions and to apply it over a case study. The methodology used was literature review and a single case study applied to Embrapa Beef Cattle, a Research Center of the Brazilian Agricultural Research Corporation (EMBRAPA). Conclusion is that the model can be used for the diagnostic of PPM on public research institutions. The importance given to strategic orientation by the studied research center became evident throughout the work. This need to integrate project portfolio with institutional strategy influences the three dimensions of the model. From the results obtained it becomes evident that putting into practice an effective strategic planning for public research institutions is paramount for project portfolio success. The tool can be enhanced through incorporation of new criteria and dimensions, serving as a starting point for further work focused on public management
Soil carbon stock in integrated crop-livestock-forest system in the Central Region of Minas Gerais.
Hypovitaminosis D and cardiometabolic risk factors in adolescents with severe obesity
Background/Objectives. Obesity is associated with cardiometabolic risk factors and with
Vitamin D deficiency. The aim of this study was to examine the relationship between 25(OH)D
concentrations and cardiometabolic risk factors in adolescents with severe obesity. Subjects/Methods.
A cross-sectional clinical assessment (body mass index, fat mass index, fat-free mass index,
waist-to-height ratio, and blood pressure) and metabolic study (triglycerides, total cholesterol,
HDL-C, LDL-C, glucose, insulin, HOMA-IR, leptin, calcium, phosphorous, calcidiol, and PTH) were
carried out in 236 adolescents diagnosed with severe obesity (BMI z-score > 3.0, 99th percentile), aged
10.2–15.8 years. The criteria of the US Endocrine Society were used for the definition of Vitamin D
status. Results. Subjects with Vitamin D deficiency had significantly elevated values (p < 0.05) for BMI
z-score, waist circumference, waist z-score, body fat percentage, fat mass index, systolic and diastolic
blood pressure, total cholesterol, triglycerides, LDL-C, insulin, HOMA-IR, leptin, and PTH than
subjects with normal Vitamin D status. There was a significant negative correlation (p < 0.05) of serum
25(OH)D levels with body fat percentage, FMI, systolic BP, total cholesterol, triglyceride, LDL-C,
glucose, insulin, HOMA-IR, leptin, and PTH. Conclusions. Low Vitamin D levels in adolescents with
severe obesity were significantly associated with some cardiometabolic risk factors, including body
mass index, waist circumference, fat mass index, high blood pressure, impaired lipid profile, and
insulin resistance
Integrated biocatalytic platform based on aqueous biphasic systems for the sustainable oligomerization of rutin
Rutin is a known antioxidant compound that displays a broad range of biological activities and health-related benefits but presents a low water solubility that can be overcome by its polymerization. In this work, biocompatible aqueous biphasic systems composed of the ionic liquid cholinium dihydrogen phosphate ([CH][DHph]) and the polymer poly(ethylene glycol) 600 (PEG 600) were investigated as an efficient integrated reaction–separation platform for the laccase-catalyzed oligomerization of rutin. Two different approaches were studied to reuse laccase in several oligorutin production cycles, the main difference between them being the use of monophasic or biphasic regimes during the oligomerization reaction. The use of a biphasic regime in the second approach (heterogeneous reaction medium) allowed the successful reuse of the biocatalyst in three consecutive reaction–separation cycles while achieving noteworthy rutin oligomerization yields (95% in the first cycle, 91% in the second cycle, and 89% in the last cycle). These remarkable results were caused by the combination of the increased solubility of rutin in the PEG-rich phase together with the enhanced catalytic performance of laccase in the [Ch][DHph]-rich phase, alongside with the optimization of the pH of the reaction medium straightly linked to enzyme stability. Finally, a life-cycle assessment was performed to compare this integrated reaction–separation platform to three alternative processes, reinforcing its sustainabilityThis research was supported by the Spanish Government (AEI) through the RTI2018-094482-J-I00 project. This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020 & UIDP/50011/2020, financed by national funds through the Portuguese Foundation for Science and Technology/MCTES. The programme is cofunded by FEDER (UE). A.P.M.T. thanks the FCT for the research contract CEECIND/2020/01867. G.E. thanks the Spanish MICIU for her Ramón y Cajal contract (RYC2018- 024846-I). A.M.-M. thanks the Programa de axudas á etapa predoutoral da Xunta de Galicia (ED481A-2018/023)S
Glutamine and cystine-enriched diets modulate aquaporins gene expression in the small intestine of piglets
Research Areas: Science & Technology ; Other TopicsABSTRACT - The regulation of glycerol permeability in the gastrointestinal tract is crucial to control fat
deposition, lipolysis and gluconeogenesis. Knowing that the amino acid glutamine is a physiological regulator of gluconeogenesis, whereas cystine promotes adiposity, herein we investigated the effects of dietary supplementation with glutamine and cystine on the serum biochemical parameters of piglets fed on amino acid-enriched diets, as well as on the transcriptional profile of membrane water and glycerol channels aquaporins (AQPs) in the ileum portion of the small intestine and its impact on intestinal permeability. Twenty male piglets
with an initial body weight of 8.8 ± 0.89 kg were allocated to four dietary treatments (n = 5)
and received, during a four week-period, a basal diet without supplementation (control) or
supplemented with 8 kg/ton of glutamine (Gln), cystine (Cys) or the combination of the two
amino acids in equal proportions (Gln + Cys). Most biochemical parameters were found
improved in piglets fed Gln and Cys diet. mRNA levels of AQP3 were found predominant
over the others. Both amino acids, individually or combined, were responsible for a consistent downregulation of AQP1, AQP7 and AQP10, without impacting on water permeability.
Conversely, Cys enriched diet upregulated AQP3 enhancing basolateral membranes glycerol permeability and downregulating glycerol kinase (GK) of intestinal cells. Altogether, our data reveal that amino acids dietary supplementation can modulate intestinal AQPs expression and unveil AQP3 as a promising target for adipogenesis regulation.info:eu-repo/semantics/publishedVersio
Integration of miRNA and mRNA expression profles reveals microRNA-regulated networks during muscle wasting in cardiac cachexia
Cardiac cachexia (CC) is a common complication of heart failure (HF) associated with muscle wasting and poor patient prognosis. Although different mechanisms have been proposed to explain muscle wasting during CC, its pathogenesis is still not understood. Here, we described an integrative analysis between miRNA and mRNA expression profiles of muscle wasting during CC. Global gene expression profiling identified 1,281 genes and 19 miRNAs differentially expressed in muscle wasting during CC. Several of these deregulated genes are known or putative targets of the altered miRNAs, including miR-29a-3p, miR-29b-3p, miR-210-5p, miR-214, and miR-489. Gene ontology analysis on integrative mRNA/miRNA expression profiling data revealed miRNA interactions affecting genes that regulate extra-cellular matrix (ECM) organization, proteasome protein degradation, citric acid cycle and respiratory electron transport. We further identified 11 miRNAs, including miR-29a-3p and miR-29b-3p, which target 21 transcripts encoding the collagen proteins related to ECM organization. Integrative miRNA and mRNA global expression data allowed us to identify miRNA target genes involved in skeletal muscle wasting in CC. Our functional experiments in C2C12 cells confirmed that miR-29b down-regulates collagen genes and contributes to muscle cell atrophy. Collectively, our results suggest that key ECM-associated miRNAs and their target genes may contribute to CC in HF
Clusiaxanthone and tocotrienol Series from Clusia pernambucensis and their antileishmanial activity
Phytochemical analysis of the ethyl acetate extract from the stem bark of Clusia pernambucensis G. Mariz, Clusiaceae, a Brazilian Cerrado species, led to the isolation and full characterization of a new xanthone, 1,7-dihydroxy-2-(3-methyl-2-butenyl)-6',6'-dimethylpyrano(2',3':3,4)xanthone, namely clusiaxanthone. Four previously unreported tocotrienols from this species were also isolated. A derivative was obtained from clusiaxanthone, 1-hydroxy,7-methoxy-2-(3-methyl2-butenyl)-6',6'-dimethylpyrano(2',3':3,4)xanthone (7-O-methylclusiaxanthone), and an additional derivative was obtained from Z- δ -tocotrienoloic acid. The structures of these compounds were established based on data from ¹H and 13C nuclear magnetic resonance (1D and 2D NMR), high resolution electrospray ionization mass spectrometry (HRESIMS) and infrared spectroscopy. The clusiaxanthone and its derivative were able to control macrophage infection by Leishmania (Leishmania) amazonensis amastigotes (IC50 = 66.9 and 57.4 µM, respectively). The cytotoxicity of the compounds was assessed in BALB/c mouse peritoneal macrophages.A análise fitoquímica do extrato acetato de etila da casca do caule de Clusia pernambucensis G. Mariz, Clusiaceae, uma espécie do Cerrado brasileiro, conduziu ao isolamento e caracterização completa de uma nova xantona, 1,7-dihidróxi-2-(3-metil-2-butenil)-6',6'-dimetilpirano(2',3':3,4) xantona, denominada clusiaxantona. Quatro tocotrienóis ainda não relatados nesta espécie também foram isolados. Um derivado foi obtido a partir da clusiaxantona, 1-hidróxi,7-metóxi-2-(3-metil2-butenil)-6',6'-dimetilpirano(2',3':3,4)xantona (7-O-metil-clusiaxantona), e um segundo derivado foi obtido a partir do ácido Z- δ -tocotrienolóico. As estruturas foram estabelecidas com base em dados de ressonância magnética nuclear de ¹H e 13C (NMR 1D e 2D), espectrometria de massa com ionização por electrospray de alta resolução (HRESIMS) e espectroscopia no infravermelho. No controle da infecção de macrófagos com amastigotas de Leishmania (Leishmania) amazonensis, os compostos ativos foram clusiaxantona e seu derivado (CI50 = 66,9 e 57,4 µM, respectivamente). A citotoxicidade dos compostos foi determinada em macrófagos peritoneais de camundongos BALB/c
Incidence and diversity of the fungal genera Aspergillus and Penicillium in Portuguese almonds and chestnuts
Almonds (Prunus dulcis (Miller) D.A. Webb) and European (sweet) chestnuts (Castanea sativa Miller) are of great economic and social impact in Mediterranean countries, and in some areas they constitute the main income of rural populations. Despite all efforts to control fungal contamination, toxigenic fungi are ubiquitous in nature and occur regularly in worldwide food supplies, and these nuts are no exception. This work aimed to provide knowledge on the general mycobiota of Portuguese almonds and chestnuts, and its evolution from field to the end of storage. For this matter, 45 field chestnut samples and 36 almond samples (30 field samples and six storage samples) were collected in Trás-os-Montes, Portugal. All fungi belonging to genus Aspergillus were isolated and identified to the section level. Fungi representative of other genera were identified to the genus level. In the field, chestnuts were mainly contaminated with the genera Fusarium, Cladosporium, Alternaria and Penicillium, and the genus Aspergillus was only rarely found, whereas almonds were more contaminated with Aspergillus. In almonds, Aspergillus incidence increased significantly from field to the end of storage, but diversity decreased, with potentially toxigenic isolates belonging to sections Flavi and Nigri becoming more significant and widespread throughout storage. These fungi were determined to be moderately associated, which can be indicative of mycotoxin co-contamination problems if adequate storage conditions are not secured.P. Rodrigues was supported by grants SFRH/BD/28332/2006 from Fundacao para a Ciencia e a Tecnologia (FCT), and SFRH/PROTEC/49555/2009 from FCT and Polytechnic Institute of Braganca, Portugal
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