As hydropower development expands across lowland tropical forests,flooding and concomitant insular fragmentation have become important threats to biodiversity.Newly created insular landscapes serve as natural laborato...As hydropower development expands across lowland tropical forests,flooding and concomitant insular fragmentation have become important threats to biodiversity.Newly created insular landscapes serve as natural laboratories to investigate biodiversity responses to fragmentation.One of these most iconic landscapes is the Balbina Hydroelectric Reservoir in Brazilian Amazonia,occupying>400000 ha and comprising>3500 forest islands.Here,we synthesise the current knowledge on responses of a wide range of biological groups to insular fragmentation at Balbina.Sampling has largely concentrated on a set of 22 islands and three mainland sites.In total,39 studies were conducted over nearly two decades,covering 17 vertebrate,invertebrate,and plant taxa.Although species responses varied according to taxonomic group,island area was consistently included and played a pivotal role in 66.7%of all studies examining patterns of species diversity.Species persistence was further affected by species traits,mostly related to species capacity to use/traverse the aquatic matrix or tolerate habitat degradation,as noted for species of vertebrates and orchid bees.Further research is needed to improve our understanding of such effects on wider ecosystem functioning.Environmental Impact Assessments must account for changes in both the remaining habitat amount and configuration,and subsequent long-term species losses.展开更多
Hydropower development has become an important driver of habitat loss and fragmentation across lowland tropical forests.Despite ample evidence on the detrimental effects of insular habitat fragmentation on biodiversit...Hydropower development has become an important driver of habitat loss and fragmentation across lowland tropical forests.Despite ample evidence on the detrimental effects of insular habitat fragmentation on biodiversity,invertebrate taxa,that may be critical to ecosystem functioning,have been overlooked.We assessed the assemblage-level responses of social wasps to forest insularization induced by the Balbina Hydroelectric Dam in Central Brazilian Amazonia.Employing Malaise trapping,we captured wasps on 27 forest islands and three continuous forests.We constructed Generalized Linear Models and employed a model selection approach to examine the impact of local variables(fire severity(FIRE)and basal area of pioneer tree species(PIONEER))and landscape-scale variables(amount of habitat(COVER))on patterns of species richness,composition,and body size of wasps.A total of 374 individuals(29 species)were collected across all sampling sites.COVER was the main predictor of species richness,while PIONEER was the only variable that explained variation in community composition,with a negative effect on body size.Our results add evidence to the pervasive impacts of large hydroelectric dams on tropical forest biodiversity,and suggest that social wasps,among other invertebrates,can be used as bioindicators in infrastructure development projects.展开更多
To evaluate the characteristics and synthesis activity of osteoblasts extracted from the calvaria of offspring of rats exposed to maternal hyperthyroidism.Twelve adult Wistar rats were divided into two groups,one cont...To evaluate the characteristics and synthesis activity of osteoblasts extracted from the calvaria of offspring of rats exposed to maternal hyperthyroidism.Twelve adult Wistar rats were divided into two groups,one control and one treated with daily administration of L-thyroxine by an orogastric tube(50μg/animal/day)during pregnancy.Three days after delivery and confirmation of the mothers’hyperthyroidism,the offspring were euthanized for the extraction of osteoblasts from the calvaria.At 7,14,and 21 days,proliferation activity was assessed using MTT assay,while alkaline phosphatase(ALP)activity was assessed by the BCIP/NBT method.At 21 days,the total area of the mineralized matrix stained by von Kossa was evaluated by morphometry.The expression of gene transcripts for Runx2,Bmp2,Fgfr1,collagen type 1(Col1),osteocalcin(Oc),and osteopontin(Op)were evaluated by real-time RT-PCR.Means were compared using the Student’s t-test.FA activity was significantly higher at 14 and 21 days in cultures of osteoblasts extracted from offspring exposed to maternal hyperthyroidism,while MTT conversion was significantly lower at 21 days in this group.Osteoblast cultures of neonates exposed to maternal hyperthyroidism also showed a larger total area of mineralized matrix and greater expression of gene transcripts for Oc and Op.Maternal hyperthyroidism increases the activity of matrix synthesis,alkaline phosphatase activity,and expression of gene transcripts for osteocalcin and osteopontin in the osteoblasts,extracted from the calvaria of the offspring,which may be one of the mechanisms of premature fusion of cranial sutures.展开更多
BACKGROUND Group B Streptococcus(GBS)is a normal component of the gastrointestinal and genital microbiota in humans and can lead to important infections in newborns.AIM To compare GBS isolation and identification meth...BACKGROUND Group B Streptococcus(GBS)is a normal component of the gastrointestinal and genital microbiota in humans and can lead to important infections in newborns.AIM To compare GBS isolation and identification methods as well as to assess the antibiotic susceptibility and to identify resistance genes in GBS strains from pregnant women attended in healthcare services from the city of Vitória da Conquista,in Bahia State,Brazil.METHODS From January 2017 to February 2018,vaginorectal swabs were obtained from 186 participants and the samples were seeded onto chromogenic agar for GBS before and after inoculation in selective broth.Confirmatory identification using 3 CAMP and latex tests was performed in samples with GBS-suggestive colonies.Then,disk diffusion antibiograms were performed in GBS-positive samples,and the detection of the resistance genes ermB,ermTR,mefA,and linB in the clindamycin and/or erythromycin-resistant samples was carried out.RESULTS Thirty-two samples(17.2%)were GBS-positive.The culture in chromogenic agar after sample incubation in selective broth was the most sensitive method(96.9%)for GBS detection.All isolates were susceptible to penicillin,ampicillin,cefotaxime,and vancomycin.Clindamycin resistance was observed in 6 samples(18.8%),while 8 samples(25%)were erythromycin-resistant.All erythromycin and/or clindamycin-resistant GBS strains had negative D-tests.Two strains(25%)presented an M phenotype and 6 isolates(75%)presented a cMLSB phenotype.The ermB gene was identified in 4 samples(44.4%),the mefA gene was also found in 4 samples(44.4%),the ermTR gene was identified in 1 isolate(11.1%),and the linB gene was not found in any isolate.CONCLUSION This study evidenced that the screening for SGB can be performed by means of various methods,including chromogenic media,and that the chemoprophylaxis for pregnant women who cannot use penicillin must be susceptibility-guided.展开更多
Cacao is a crop of global relevance that faces constant demands for improved bean yield.However,little is known about the genomic regions controlling the crop yield and genes involved in cacao bean filling.Hence,to id...Cacao is a crop of global relevance that faces constant demands for improved bean yield.However,little is known about the genomic regions controlling the crop yield and genes involved in cacao bean filling.Hence,to identify the quantitative trait loci(QTL)associated with cacao yield and bean filling,we performed a QTL mapping in a segregating mapping population comprising 459 trees of a cross between‘TSH 1188’and‘CCN 51’.All variables showed considerable phenotypic variation and had moderate to high heritability values.We identified 24 QTLs using a genetic linkage map that contains 3526 single nucleotide polymorphism(SNP)markers.Haplotype analysis at the significant QTL region on chromosome IV pointed to the alleles from the maternal parent,‘TSH 1188’,as the ones that affect the cacao yield components the most.The recombination events identified within these QTL regions allowed us to identify candidate genes that may take part in the different steps of pod growth and bean filling.Such candidate genes seem to play a significant role in the source-to-sink transport of sugars and amino acids,and lipid metabolism,such as fatty acid production.The SNP markers mapped in our study are now being used to select potential highyielding cacao varieties through marker-assisted selection in our existing cacao-breeding experiments.展开更多
The scope and aim of this work is to describe the two-body interaction mediated by a particle （either the scalar or the gauge boson） within the light-front formulation. To do this, first of all we point out the impo...The scope and aim of this work is to describe the two-body interaction mediated by a particle （either the scalar or the gauge boson） within the light-front formulation. To do this, first of all we point out the importance of propagators and Green functions in Quantum Mechanics. Then we project the covariant quantum propagator onto the light front time to get the propagator for scalar particles in these coordinates. This operator propagates the wave function from x＋ = 0 to x＋ 〉 0. It corresponds to the definition of the time ordering operation in the light front time x＋. We calculate the light-front Green＇s function for 2 interacting bosons propagating forward in x＋. We also show how to write down the light front Green＇s function from the Feynman propagator and finally make a generalization to N bosons.展开更多
The study of the propagation of infectious diseases in urban centers finds a close connection with their population's social characteristics and behavior.This work performs a spatial analysis of dengue cases in ur...The study of the propagation of infectious diseases in urban centers finds a close connection with their population's social characteristics and behavior.This work performs a spatial analysis of dengue cases in urban centers based on the basic reproduction numbers,R0,and incidence by planning areas(PAs),as well as their correlations with the Human Development Index(HDI)and the number of trips.We analyzed dengue epidemics in 2002 at two Brazilian urban centers,Belo Horizonte(BH)and Rio de Janeiro(RJ),using PAs as spatial units.Our results reveal heterogeneous spatial scenarios for both cities,with very weak correlations between R0 and both the number of trips and the HDI;in BH,the values of R0 show a less spatial heterogeneous pattern than in RJ.For BH,there are moderate correlations between incidence and both the number of trips and the HDI;meanwhile,they weakly correlate for RJ.Finally,the absence of strong correlations between the considered measures indicates that the transmission process should be treated considering the city as a whole.展开更多
Cacao is a tree crop of high economic importance and the subject of several studies aiming the genetic improvement of the species with the incorporation of characteristics that are agronomically important to create su...Cacao is a tree crop of high economic importance and the subject of several studies aiming the genetic improvement of the species with the incorporation of characteristics that are agronomically important to create superior genotypes. In this context, this study aimed to characterize 22 genotypes of cacao for sexual compatibility, which is a trait that is strongly associated with yield. Additionally, we identify genotypes incompatible with clone TSH-1188 through controlled intercrosses, due to the great importance of this clone in cocoa breeding. Fifteen genotypes were characterized as self-incompatible and other seven as self-compatible, considering the retention index (20%) of self-pollinated flowers. Nine genotypes were characterized for the first time: CCN-16, COCA-3310, COCA-3370/5, EB-1017, IMC-119, IMC-97, LCTEEN-37A, NA-45, and UF-612. Cacao genotypes showed flower retention index ranging from 0.0% to 55.1% after 15 days of self-pollinations. The number of retained flowers varied after self-pollination of cacao genotypes at 1, 5 and 15 days after pollination. CCN-51, Catongo, CCN-10 and P-4B, were the genotypes with minor losses of flowers after 15 days of pollination, while IMC-119 and TSH-516 had 100% of loss of flowers between 1 and 5 days after pollination. Moreover, the flower retention index 15 days after cross-pollination with TSH-1188 ranged from 0.0% to 87.5% among the tested genotypes. The results of cross-pollinations identified two genotypes that are incompatibles, EB-1017 and IMC-119. This result is important for future allelic studies of incompatibility in cacao, because it might indicate that these genotypes share the same self-incompatibility allele(s). We conclude, therefore, that this study enable the characterization of this working collection of cocoa germplasm for sexual compatibility and this information is important for subsequent crosses between cacao genotypes.展开更多
In Zimapan Valley, Mexico, up to 1.1 mg·L-1 of arsenic concentrations have been detected in deep wells that are used as drinking water supply for almost 39,000 people, which could have been exposed to level...In Zimapan Valley, Mexico, up to 1.1 mg·L-1 of arsenic concentrations have been detected in deep wells that are used as drinking water supply for almost 39,000 people, which could have been exposed to levels higher than 10 μg·L-1 of arsenic, the maximum level recommended by the World Health Organization. Chronic consumption of water contaminated with arsenic can cause several diseases, including cancer. For it, the implementation of practical and economical methods to remove arsenic from drinking water is crucial to protect the population health. In this work, an electrochemical method to remove arsenic from drinking water is described. The process, monitored by Tyndall effect, utilizes Cu2+ and Zn2+ ions from a brass electrode in an electrochemical cell with water as electrolyte. Results show that the EC process reduces the concentration of the arsenic diluted in Zimapan water to a level below the limit of detection of the atomic absorption spectrophotometer employed. Arsenic was removed through the formation of Cu and Zn arsenic compounds. Cu2+ and Zn2+ ions form a hydroxide and eventually polycrystalline precipitation of kottigite and cornubite complexes (identified by energy-dispersive X-ray spectroscopy and X-ray diffraction), which are then filtered to eliminate the precipitated arsenic compounds.展开更多
The current outbreak of Ebola virus in West Africa has become a devastating problem.with a mortality rate around 51%;over 3132 deaths have been confirmed and even more arc expected in this case.The virus causes a char...The current outbreak of Ebola virus in West Africa has become a devastating problem.with a mortality rate around 51%;over 3132 deaths have been confirmed and even more arc expected in this case.The virus causes a characteristic disease known as hemorrhagic fever.Its symptoms range from nonspecific signs such as fever,lo more specific problems such as serious bleeding.Transmission occurs easily when a person comes in contact with contaminated fluids.Treatment is supportive because there are still no specific drugs for use.The present review focuses on the main features related to the Ebola virus,its transmission,pathogenesis,treatment and control forms.There is little in-depth knowledge about this disease,but its severily requires attention and information lo prevent a worse scenario than the current.展开更多
In this work numerical codes carried out in a multiconfiguration Har-tree-Fock relativistic (HFR) approach for the P IV ion are used to obtain the oscillator strengths of each transition as well as the lifetimes of ea...In this work numerical codes carried out in a multiconfiguration Har-tree-Fock relativistic (HFR) approach for the P IV ion are used to obtain the oscillator strengths of each transition as well as the lifetimes of each energy level. With the existing data from several authors that contributed to the spectrum using different light sources, and optimizing the electrostatic parameters by a least-squares procedure when replacing the theoretical values by the experimental ones in the energy matrices, one obtains closer values and according to the observations for the intensities, and also of the lifetimes closer to those that would be obtained experimentally.展开更多
The P XIII spectrum has been analyzed by several authors using different light sources. The semi-empirical oscillator strengths (gf) and the lifetimes presented in this work for all known P XIII spectral lines and ene...The P XIII spectrum has been analyzed by several authors using different light sources. The semi-empirical oscillator strengths (gf) and the lifetimes presented in this work for all known P XIII spectral lines and energy levels were carried out in a multi-configuration Hartree-Fock relativistic (HFR) approach. In this calculation, the electrostatic parameters were optimized by a least-squares procedure in order to improve the adjustment of theoretical to experimental energy levels. The method produces gf-values that are in agreement with intensity observations and lifetime values closer to the experimental ones.展开更多
We have characterized the number of ovules per ovary (NoOV) in cacao plants originated from crossing the clones CCN 51 and TSH 1188 (segregating progeny) and determined the heritability of this characteristic in order...We have characterized the number of ovules per ovary (NoOV) in cacao plants originated from crossing the clones CCN 51 and TSH 1188 (segregating progeny) and determined the heritability of this characteristic in order to select plants with higher NoOV in this progeny. The NoOV was calculated as the average of 10 flowers per plant and ranged from 44.8 to 58.6 between the six clones (two parents and four clones belonging to their genealogy). In the progeny (n = 209 plants) the NoOV averaged 54.3 (range 44.1 to 67.8). The NoOV was distributed uniformly among the progeny indicating that this trait is conditioned by polygenes. Its heritability was estimated at 67.7%. The 32 plants with NoOV similar or superior to the genitor CCN 51 (highest amount among clones) were selected for use in the genetic improvement program. We showed that this population is suitable for genetic mapping, molecular marker identification and selection of superior cacao genotypes.展开更多
Sickle cell anemia (SCA) is a genetically inherited hemolytic disorder characterized by chronic inflammation. Cytokine expression affects the pivotal pathways that contribute to disease pathogenesis, but the mechanism...Sickle cell anemia (SCA) is a genetically inherited hemolytic disorder characterized by chronic inflammation. Cytokine expression affects the pivotal pathways that contribute to disease pathogenesis, but the mechanisms involved are not well understood. SCA is associated with a proinflammatory state, and an enhanced inflammatory response occurs during vasoocclusive crisis. The immune system thus plays an important role in this inflammatory condition, with several cell types secreting pro-inflammatory cytokines that contribute to the occurrence of common cyclical events in SCA patients, such as hemolysis, vascular occlusion and inflammation. Studies of these cytokines and chemokines in SCA patients have clarified the mechanisms that underlie this disease and highlighted the need for a better understanding of cytokine participation in SCA pathophysiology.展开更多
Sickle cell disease (SCD) is a genetic disorder characterized by a chronic inflammatory process, and new biomarkers have been studied as promising molecules for understanding the inflammation in its pathophysiology. T...Sickle cell disease (SCD) is a genetic disorder characterized by a chronic inflammatory process, and new biomarkers have been studied as promising molecules for understanding the inflammation in its pathophysiology. The hemolysis and the release of molecules associated to the hemoglobin (Hb) catabolism, such as free Hb, iron, and heme, generating a oxidant environment with production of reactive oxygen and nitrogen species. The immune system plays a very important role in the inflammation, with cells secreting pro-inflammatory cytokines and chemokines. There is also a nitric oxide (NO) resistance state, with an impaired NO bioactivity, leading to a vascular dys-function;activation of platelet, leukocytes, erythrocytes, and endothelial cells, with expression of adhesion molecules and its ligands, and several receptors, that altogether participate at inflammatory process. During inflammation, there is an increase of dendritic cells (DCs) expresse toll like receptors (TLR), but the role of DCs and TLR in SCD pathogenesis is unclear. Also, there are molecules contributing for enhance the endothelium dysfunction, such as homocysteine that has been associated with vascular complications in the pathology of other diseases and it may contribute to the vascular complications presented by SCD patients. Circulating microparticules (MPs) levels are augmented in several diseases and have been described in SCD, where cells membrane compounds are associated to cell’s thrombotic and coagulation state, such as tissue factor and phosphatidylserine (PS), which may contribute to endothelial dysfunction. The knowledge of all these biomarkers may contribute to new therapeutic approach discover, improveing SCD patient life quality.展开更多
Endophytic fungi were identified from different parts of the medicinal parasitic mistletoe Cladocolea micrantha and from its host Anacardium occidentale, suggesting a strict host-parasite relationship. Eight fungal en...Endophytic fungi were identified from different parts of the medicinal parasitic mistletoe Cladocolea micrantha and from its host Anacardium occidentale, suggesting a strict host-parasite relationship. Eight fungal endophytes were isolated and morphologically characterized. The ascomycete Guignardia mangiferae and strains of Mycelia sterilia were prevalent in the isolations. The unequivocal identification of Guignardia mangiferae at a probabilistic degree close to 100% was carried out by DNA extraction followed by PCR analyses of the ITS-1 and ITS-2 regions and comparison of the genetic sequence with the NCBI database.展开更多
Aims Screening tree species in tropical rainforest according to their shade tolerance is important to efficiently manage the native trees of economic significance in secondary forest enrichment regimes.The objective o...Aims Screening tree species in tropical rainforest according to their shade tolerance is important to efficiently manage the native trees of economic significance in secondary forest enrichment regimes.The objective of this study was to determine the whole-plant light compensation point(WPLCP)and compare the phenotypic plasticity in relation to growth and carbon allocation of Cariniana legalis and Gallesia integrifolia seedlings under low light availability.Methods Seedlings were cultivated for 77 days under conditions of five photosynthetically active radiation(PAR)(0.02,1.1,2.3,4.5 and 5.9 mol photons m^(−2)day^(−1))in three replicates.Growth and carbon allocation variables were determined.Important Findings Growth rates of C.legalis were higher and lower than those of G.integrifolia under 1.1 and 5.9 mol photons m^(−2)day^(−1),respectively.The WPLCP differed significantly between the two species.In accordance with the criteria of the shade tolerance classification for these two tropical tree species,our results showed that C.legalis had lower WPLCP and phenotypic plasticity in terms of higher growth rates and greater shade tolerance than G.integrifolia.From a practical point of view,we demonstrated that the differential linkage between growth and changing PAR between the two species can become a useful tool for comparing and selecting tree species in forest enrichment projects.展开更多
In this work we consider the propagation of two fermion fields interacting with each other by the exchange of intermediate scalar bosons in the light front. We obtain the corrections up to fourth order in the coupling...In this work we consider the propagation of two fermion fields interacting with each other by the exchange of intermediate scalar bosons in the light front. We obtain the corrections up to fourth order in the coupling constant using hierarchical equations in order to obtain the bound state equation （Bethe-Salpeter equation）.展开更多
Aims Climate and soil are among the most important factors determin-ing variation in tree communities,but their effects have not been thoroughly elucidated to date for many vegetation features.In this study,we evaluat...Aims Climate and soil are among the most important factors determin-ing variation in tree communities,but their effects have not been thoroughly elucidated to date for many vegetation features.In this study,we evaluate how climate and soil gradients affect gradients of vegetation composition,species diversity and dominance,structure and functional traits(seed mass and wood density)using over 327000 trees in 158 sites distributed along environmental gradients in the transitions among the Atlantic forest,Cerrado and Caatinga in Minas Gerais State(MG),Brazil(nearly 600000 km2).Methods Gradients in species,genus and family abundance in addition to basal area,stem density,species diversity(Fisher’s alpha),domin-ance percentage,seed mass and wood density were correlated using multiple regressions with environmental variables,as summarized in four principal component analysis axes(two climatic-precipi-tation seasonality and temperature range-and two edaphic-soil fertility and soil moisture).Additionally,ordinary kriging maps were used to better illustrate the gradients.Important Findings Multiple regression models indicate that all variables but domin-ance percentage were affected by one or more of the environmental gradients,but the average R2 was low(26.25%).Kriging maps rein-forced the patterns observed in the regression models.Precipitation seasonality and soil moisture gradients were the most important gra-dients affecting vegetation features.This finding suggests that water availability is an important determinant of vegetation features in these vegetation transitions.展开更多
基金supported byÁreas Protegidas da Amazônia(ARPA)Amazonas Distribuidora de Energia S.A.,and Associação Comunidade Waimiri Atroari+4 种基金Rufford Foundation(grant number 13675-1)the Conservation Food and Health Foundation,and Idea WildNational Geographic Society grant(NGS-93497C-22)awarded to CAP.I.J is funded through a UKRI Future Leaders Fellowship(MR/T019018/1)M.B received a productivity grant from CNPq(304189/2022-7)European Union’s Horizon 2020 research and innovation programme under the grant agreement No.854248(TROPIBIO)。
文摘As hydropower development expands across lowland tropical forests,flooding and concomitant insular fragmentation have become important threats to biodiversity.Newly created insular landscapes serve as natural laboratories to investigate biodiversity responses to fragmentation.One of these most iconic landscapes is the Balbina Hydroelectric Reservoir in Brazilian Amazonia,occupying>400000 ha and comprising>3500 forest islands.Here,we synthesise the current knowledge on responses of a wide range of biological groups to insular fragmentation at Balbina.Sampling has largely concentrated on a set of 22 islands and three mainland sites.In total,39 studies were conducted over nearly two decades,covering 17 vertebrate,invertebrate,and plant taxa.Although species responses varied according to taxonomic group,island area was consistently included and played a pivotal role in 66.7%of all studies examining patterns of species diversity.Species persistence was further affected by species traits,mostly related to species capacity to use/traverse the aquatic matrix or tolerate habitat degradation,as noted for species of vertebrates and orchid bees.Further research is needed to improve our understanding of such effects on wider ecosystem functioning.Environmental Impact Assessments must account for changes in both the remaining habitat amount and configuration,and subsequent long-term species losses.
基金supported by a NERC grant to C.A.P.(NE/J01401X/1)a Science Without Borders postdoctoral fellowship awarded to D.S.(CNPq grant 246975/2012-1)+1 种基金M.B.received a productivity grant from CNPq(304189/2022-7)supported by the inaugural Frontiers Planet Prize。
文摘Hydropower development has become an important driver of habitat loss and fragmentation across lowland tropical forests.Despite ample evidence on the detrimental effects of insular habitat fragmentation on biodiversity,invertebrate taxa,that may be critical to ecosystem functioning,have been overlooked.We assessed the assemblage-level responses of social wasps to forest insularization induced by the Balbina Hydroelectric Dam in Central Brazilian Amazonia.Employing Malaise trapping,we captured wasps on 27 forest islands and three continuous forests.We constructed Generalized Linear Models and employed a model selection approach to examine the impact of local variables(fire severity(FIRE)and basal area of pioneer tree species(PIONEER))and landscape-scale variables(amount of habitat(COVER))on patterns of species richness,composition,and body size of wasps.A total of 374 individuals(29 species)were collected across all sampling sites.COVER was the main predictor of species richness,while PIONEER was the only variable that explained variation in community composition,with a negative effect on body size.Our results add evidence to the pervasive impacts of large hydroelectric dams on tropical forest biodiversity,and suggest that social wasps,among other invertebrates,can be used as bioindicators in infrastructure development projects.
基金supported by grants from the Conselho Nacional de Desenvolvimento Científico e Tecnológico(CNPq)Fundação de Amparo a Pesquisa de Minas Gerais(Fapemig)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior(Capes).
文摘To evaluate the characteristics and synthesis activity of osteoblasts extracted from the calvaria of offspring of rats exposed to maternal hyperthyroidism.Twelve adult Wistar rats were divided into two groups,one control and one treated with daily administration of L-thyroxine by an orogastric tube(50μg/animal/day)during pregnancy.Three days after delivery and confirmation of the mothers’hyperthyroidism,the offspring were euthanized for the extraction of osteoblasts from the calvaria.At 7,14,and 21 days,proliferation activity was assessed using MTT assay,while alkaline phosphatase(ALP)activity was assessed by the BCIP/NBT method.At 21 days,the total area of the mineralized matrix stained by von Kossa was evaluated by morphometry.The expression of gene transcripts for Runx2,Bmp2,Fgfr1,collagen type 1(Col1),osteocalcin(Oc),and osteopontin(Op)were evaluated by real-time RT-PCR.Means were compared using the Student’s t-test.FA activity was significantly higher at 14 and 21 days in cultures of osteoblasts extracted from offspring exposed to maternal hyperthyroidism,while MTT conversion was significantly lower at 21 days in this group.Osteoblast cultures of neonates exposed to maternal hyperthyroidism also showed a larger total area of mineralized matrix and greater expression of gene transcripts for Oc and Op.Maternal hyperthyroidism increases the activity of matrix synthesis,alkaline phosphatase activity,and expression of gene transcripts for osteocalcin and osteopontin in the osteoblasts,extracted from the calvaria of the offspring,which may be one of the mechanisms of premature fusion of cranial sutures.
文摘BACKGROUND Group B Streptococcus(GBS)is a normal component of the gastrointestinal and genital microbiota in humans and can lead to important infections in newborns.AIM To compare GBS isolation and identification methods as well as to assess the antibiotic susceptibility and to identify resistance genes in GBS strains from pregnant women attended in healthcare services from the city of Vitória da Conquista,in Bahia State,Brazil.METHODS From January 2017 to February 2018,vaginorectal swabs were obtained from 186 participants and the samples were seeded onto chromogenic agar for GBS before and after inoculation in selective broth.Confirmatory identification using 3 CAMP and latex tests was performed in samples with GBS-suggestive colonies.Then,disk diffusion antibiograms were performed in GBS-positive samples,and the detection of the resistance genes ermB,ermTR,mefA,and linB in the clindamycin and/or erythromycin-resistant samples was carried out.RESULTS Thirty-two samples(17.2%)were GBS-positive.The culture in chromogenic agar after sample incubation in selective broth was the most sensitive method(96.9%)for GBS detection.All isolates were susceptible to penicillin,ampicillin,cefotaxime,and vancomycin.Clindamycin resistance was observed in 6 samples(18.8%),while 8 samples(25%)were erythromycin-resistant.All erythromycin and/or clindamycin-resistant GBS strains had negative D-tests.Two strains(25%)presented an M phenotype and 6 isolates(75%)presented a cMLSB phenotype.The ermB gene was identified in 4 samples(44.4%),the mefA gene was also found in 4 samples(44.4%),the ermTR gene was identified in 1 isolate(11.1%),and the linB gene was not found in any isolate.CONCLUSION This study evidenced that the screening for SGB can be performed by means of various methods,including chromogenic media,and that the chemoprophylaxis for pregnant women who cannot use penicillin must be susceptibility-guided.
文摘Cacao is a crop of global relevance that faces constant demands for improved bean yield.However,little is known about the genomic regions controlling the crop yield and genes involved in cacao bean filling.Hence,to identify the quantitative trait loci(QTL)associated with cacao yield and bean filling,we performed a QTL mapping in a segregating mapping population comprising 459 trees of a cross between‘TSH 1188’and‘CCN 51’.All variables showed considerable phenotypic variation and had moderate to high heritability values.We identified 24 QTLs using a genetic linkage map that contains 3526 single nucleotide polymorphism(SNP)markers.Haplotype analysis at the significant QTL region on chromosome IV pointed to the alleles from the maternal parent,‘TSH 1188’,as the ones that affect the cacao yield components the most.The recombination events identified within these QTL regions allowed us to identify candidate genes that may take part in the different steps of pod growth and bean filling.Such candidate genes seem to play a significant role in the source-to-sink transport of sugars and amino acids,and lipid metabolism,such as fatty acid production.The SNP markers mapped in our study are now being used to select potential highyielding cacao varieties through marker-assisted selection in our existing cacao-breeding experiments.
文摘The scope and aim of this work is to describe the two-body interaction mediated by a particle （either the scalar or the gauge boson） within the light-front formulation. To do this, first of all we point out the importance of propagators and Green functions in Quantum Mechanics. Then we project the covariant quantum propagator onto the light front time to get the propagator for scalar particles in these coordinates. This operator propagates the wave function from x＋ = 0 to x＋ 〉 0. It corresponds to the definition of the time ordering operation in the light front time x＋. We calculate the light-front Green＇s function for 2 interacting bosons propagating forward in x＋. We also show how to write down the light front Green＇s function from the Feynman propagator and finally make a generalization to N bosons.
基金support of the National Council of Technological and Scientific Development,CNPq,Brazil(grant no.305941/2021-6)support of Coordenação de Aperfeiçoamento de Pessoal de Nível Superior/Programa de Excelência Acadêmica(CAPES/PROEX)for the publication charge.
文摘The study of the propagation of infectious diseases in urban centers finds a close connection with their population's social characteristics and behavior.This work performs a spatial analysis of dengue cases in urban centers based on the basic reproduction numbers,R0,and incidence by planning areas(PAs),as well as their correlations with the Human Development Index(HDI)and the number of trips.We analyzed dengue epidemics in 2002 at two Brazilian urban centers,Belo Horizonte(BH)and Rio de Janeiro(RJ),using PAs as spatial units.Our results reveal heterogeneous spatial scenarios for both cities,with very weak correlations between R0 and both the number of trips and the HDI;in BH,the values of R0 show a less spatial heterogeneous pattern than in RJ.For BH,there are moderate correlations between incidence and both the number of trips and the HDI;meanwhile,they weakly correlate for RJ.Finally,the absence of strong correlations between the considered measures indicates that the transmission process should be treated considering the city as a whole.
文摘Cacao is a tree crop of high economic importance and the subject of several studies aiming the genetic improvement of the species with the incorporation of characteristics that are agronomically important to create superior genotypes. In this context, this study aimed to characterize 22 genotypes of cacao for sexual compatibility, which is a trait that is strongly associated with yield. Additionally, we identify genotypes incompatible with clone TSH-1188 through controlled intercrosses, due to the great importance of this clone in cocoa breeding. Fifteen genotypes were characterized as self-incompatible and other seven as self-compatible, considering the retention index (20%) of self-pollinated flowers. Nine genotypes were characterized for the first time: CCN-16, COCA-3310, COCA-3370/5, EB-1017, IMC-119, IMC-97, LCTEEN-37A, NA-45, and UF-612. Cacao genotypes showed flower retention index ranging from 0.0% to 55.1% after 15 days of self-pollinations. The number of retained flowers varied after self-pollination of cacao genotypes at 1, 5 and 15 days after pollination. CCN-51, Catongo, CCN-10 and P-4B, were the genotypes with minor losses of flowers after 15 days of pollination, while IMC-119 and TSH-516 had 100% of loss of flowers between 1 and 5 days after pollination. Moreover, the flower retention index 15 days after cross-pollination with TSH-1188 ranged from 0.0% to 87.5% among the tested genotypes. The results of cross-pollinations identified two genotypes that are incompatibles, EB-1017 and IMC-119. This result is important for future allelic studies of incompatibility in cacao, because it might indicate that these genotypes share the same self-incompatibility allele(s). We conclude, therefore, that this study enable the characterization of this working collection of cocoa germplasm for sexual compatibility and this information is important for subsequent crosses between cacao genotypes.
文摘In Zimapan Valley, Mexico, up to 1.1 mg·L-1 of arsenic concentrations have been detected in deep wells that are used as drinking water supply for almost 39,000 people, which could have been exposed to levels higher than 10 μg·L-1 of arsenic, the maximum level recommended by the World Health Organization. Chronic consumption of water contaminated with arsenic can cause several diseases, including cancer. For it, the implementation of practical and economical methods to remove arsenic from drinking water is crucial to protect the population health. In this work, an electrochemical method to remove arsenic from drinking water is described. The process, monitored by Tyndall effect, utilizes Cu2+ and Zn2+ ions from a brass electrode in an electrochemical cell with water as electrolyte. Results show that the EC process reduces the concentration of the arsenic diluted in Zimapan water to a level below the limit of detection of the atomic absorption spectrophotometer employed. Arsenic was removed through the formation of Cu and Zn arsenic compounds. Cu2+ and Zn2+ ions form a hydroxide and eventually polycrystalline precipitation of kottigite and cornubite complexes (identified by energy-dispersive X-ray spectroscopy and X-ray diffraction), which are then filtered to eliminate the precipitated arsenic compounds.
文摘The current outbreak of Ebola virus in West Africa has become a devastating problem.with a mortality rate around 51%;over 3132 deaths have been confirmed and even more arc expected in this case.The virus causes a characteristic disease known as hemorrhagic fever.Its symptoms range from nonspecific signs such as fever,lo more specific problems such as serious bleeding.Transmission occurs easily when a person comes in contact with contaminated fluids.Treatment is supportive because there are still no specific drugs for use.The present review focuses on the main features related to the Ebola virus,its transmission,pathogenesis,treatment and control forms.There is little in-depth knowledge about this disease,but its severily requires attention and information lo prevent a worse scenario than the current.
文摘In this work numerical codes carried out in a multiconfiguration Har-tree-Fock relativistic (HFR) approach for the P IV ion are used to obtain the oscillator strengths of each transition as well as the lifetimes of each energy level. With the existing data from several authors that contributed to the spectrum using different light sources, and optimizing the electrostatic parameters by a least-squares procedure when replacing the theoretical values by the experimental ones in the energy matrices, one obtains closer values and according to the observations for the intensities, and also of the lifetimes closer to those that would be obtained experimentally.
文摘The P XIII spectrum has been analyzed by several authors using different light sources. The semi-empirical oscillator strengths (gf) and the lifetimes presented in this work for all known P XIII spectral lines and energy levels were carried out in a multi-configuration Hartree-Fock relativistic (HFR) approach. In this calculation, the electrostatic parameters were optimized by a least-squares procedure in order to improve the adjustment of theoretical to experimental energy levels. The method produces gf-values that are in agreement with intensity observations and lifetime values closer to the experimental ones.
文摘We have characterized the number of ovules per ovary (NoOV) in cacao plants originated from crossing the clones CCN 51 and TSH 1188 (segregating progeny) and determined the heritability of this characteristic in order to select plants with higher NoOV in this progeny. The NoOV was calculated as the average of 10 flowers per plant and ranged from 44.8 to 58.6 between the six clones (two parents and four clones belonging to their genealogy). In the progeny (n = 209 plants) the NoOV averaged 54.3 (range 44.1 to 67.8). The NoOV was distributed uniformly among the progeny indicating that this trait is conditioned by polygenes. Its heritability was estimated at 67.7%. The 32 plants with NoOV similar or superior to the genitor CCN 51 (highest amount among clones) were selected for use in the genetic improvement program. We showed that this population is suitable for genetic mapping, molecular marker identification and selection of superior cacao genotypes.
文摘Sickle cell anemia (SCA) is a genetically inherited hemolytic disorder characterized by chronic inflammation. Cytokine expression affects the pivotal pathways that contribute to disease pathogenesis, but the mechanisms involved are not well understood. SCA is associated with a proinflammatory state, and an enhanced inflammatory response occurs during vasoocclusive crisis. The immune system thus plays an important role in this inflammatory condition, with several cell types secreting pro-inflammatory cytokines that contribute to the occurrence of common cyclical events in SCA patients, such as hemolysis, vascular occlusion and inflammation. Studies of these cytokines and chemokines in SCA patients have clarified the mechanisms that underlie this disease and highlighted the need for a better understanding of cytokine participation in SCA pathophysiology.
基金supported by grants from the Brazilian National Council of Research(CNPq)(3065427/2007-5 and 484457/2007-1)(M.S.G.)the Foundation of Research and Extension of Bahia(FAPESB)(1431040053063,9073/2007 and 6234/2010)(M.S.G.)and MCD/CNPq/MS-SCTIE-DECIT(409800/2006-6),(M.S.G.).
文摘Sickle cell disease (SCD) is a genetic disorder characterized by a chronic inflammatory process, and new biomarkers have been studied as promising molecules for understanding the inflammation in its pathophysiology. The hemolysis and the release of molecules associated to the hemoglobin (Hb) catabolism, such as free Hb, iron, and heme, generating a oxidant environment with production of reactive oxygen and nitrogen species. The immune system plays a very important role in the inflammation, with cells secreting pro-inflammatory cytokines and chemokines. There is also a nitric oxide (NO) resistance state, with an impaired NO bioactivity, leading to a vascular dys-function;activation of platelet, leukocytes, erythrocytes, and endothelial cells, with expression of adhesion molecules and its ligands, and several receptors, that altogether participate at inflammatory process. During inflammation, there is an increase of dendritic cells (DCs) expresse toll like receptors (TLR), but the role of DCs and TLR in SCD pathogenesis is unclear. Also, there are molecules contributing for enhance the endothelium dysfunction, such as homocysteine that has been associated with vascular complications in the pathology of other diseases and it may contribute to the vascular complications presented by SCD patients. Circulating microparticules (MPs) levels are augmented in several diseases and have been described in SCD, where cells membrane compounds are associated to cell’s thrombotic and coagulation state, such as tissue factor and phosphatidylserine (PS), which may contribute to endothelial dysfunction. The knowledge of all these biomarkers may contribute to new therapeutic approach discover, improveing SCD patient life quality.
文摘Endophytic fungi were identified from different parts of the medicinal parasitic mistletoe Cladocolea micrantha and from its host Anacardium occidentale, suggesting a strict host-parasite relationship. Eight fungal endophytes were isolated and morphologically characterized. The ascomycete Guignardia mangiferae and strains of Mycelia sterilia were prevalent in the isolations. The unequivocal identification of Guignardia mangiferae at a probabilistic degree close to 100% was carried out by DNA extraction followed by PCR analyses of the ITS-1 and ITS-2 regions and comparison of the genetic sequence with the NCBI database.
基金Marcelo S.Mielke gratefully acknowledge CNPq(Brazilian National Council for Scientific and Technological Development)for the award of fellowship of scientific productivity(305477/2018-8).
文摘Aims Screening tree species in tropical rainforest according to their shade tolerance is important to efficiently manage the native trees of economic significance in secondary forest enrichment regimes.The objective of this study was to determine the whole-plant light compensation point(WPLCP)and compare the phenotypic plasticity in relation to growth and carbon allocation of Cariniana legalis and Gallesia integrifolia seedlings under low light availability.Methods Seedlings were cultivated for 77 days under conditions of five photosynthetically active radiation(PAR)(0.02,1.1,2.3,4.5 and 5.9 mol photons m^(−2)day^(−1))in three replicates.Growth and carbon allocation variables were determined.Important Findings Growth rates of C.legalis were higher and lower than those of G.integrifolia under 1.1 and 5.9 mol photons m^(−2)day^(−1),respectively.The WPLCP differed significantly between the two species.In accordance with the criteria of the shade tolerance classification for these two tropical tree species,our results showed that C.legalis had lower WPLCP and phenotypic plasticity in terms of higher growth rates and greater shade tolerance than G.integrifolia.From a practical point of view,we demonstrated that the differential linkage between growth and changing PAR between the two species can become a useful tool for comparing and selecting tree species in forest enrichment projects.
文摘In this work we consider the propagation of two fermion fields interacting with each other by the exchange of intermediate scalar bosons in the light front. We obtain the corrections up to fourth order in the coupling constant using hierarchical equations in order to obtain the bound state equation （Bethe-Salpeter equation）.
文摘Aims Climate and soil are among the most important factors determin-ing variation in tree communities,but their effects have not been thoroughly elucidated to date for many vegetation features.In this study,we evaluate how climate and soil gradients affect gradients of vegetation composition,species diversity and dominance,structure and functional traits(seed mass and wood density)using over 327000 trees in 158 sites distributed along environmental gradients in the transitions among the Atlantic forest,Cerrado and Caatinga in Minas Gerais State(MG),Brazil(nearly 600000 km2).Methods Gradients in species,genus and family abundance in addition to basal area,stem density,species diversity(Fisher’s alpha),domin-ance percentage,seed mass and wood density were correlated using multiple regressions with environmental variables,as summarized in four principal component analysis axes(two climatic-precipi-tation seasonality and temperature range-and two edaphic-soil fertility and soil moisture).Additionally,ordinary kriging maps were used to better illustrate the gradients.Important Findings Multiple regression models indicate that all variables but domin-ance percentage were affected by one or more of the environmental gradients,but the average R2 was low(26.25%).Kriging maps rein-forced the patterns observed in the regression models.Precipitation seasonality and soil moisture gradients were the most important gra-dients affecting vegetation features.This finding suggests that water availability is an important determinant of vegetation features in these vegetation transitions.
