769 research outputs found
Areas of natural occurrence of melipona scutellaris Latreille, 1811(Hymenoptera: Apidae) in the state of Bahia, Brazil.
The bee Melipona scutellaris is considered the reared meliponine species with the largest distribution in the North and Northeast regions of Brazil, with records from the state of Rio Grande do Norte down to the state of Bahia. Considering the importance of this species in the generation of income for family agriculture and in the preservation of areas with natural vegetation, this study aimed at providing knowledge on the distribution of natural colonies of M. scutellaris in the state of Bahia. Literature information, interviews with stinglessbee beekeepers, and expeditions were conducted to confirm the natural occurrence of the species. A total of 102 municipalities showed records for M. scutellaris, whose occurrence was observed in areas ranging from sea level up to 1,200-meter height. The occurrence of this species in the state of Bahia is considered to be restricted to municipalities on the coastal area and the Chapada Diamantina with its rainforests. Geographic coordinates, elevation, climate and vegetation data were obtained, which allowed a map to be prepared for the area of occurrence in order to support conservation and management policies for the species
Ratio of the Isolated Photon Cross Sections at \sqrt{s} = 630 and 1800 GeV
The inclusive cross section for production of isolated photons has been
measured in \pbarp collisions at GeV with the \D0 detector at
the Fermilab Tevatron Collider. The photons span a transverse energy ()
range from 7-49 GeV and have pseudorapidity . This measurement is
combined with to previous \D0 result at GeV to form a ratio
of the cross sections. Comparison of next-to-leading order QCD with the
measured cross section at 630 GeV and ratio of cross sections show satisfactory
agreement in most of the range.Comment: 7 pages. Published in Phys. Rev. Lett. 87, 251805, (2001
Sialic Acid Glycobiology Unveils Trypanosoma cruzi Trypomastigote Membrane Physiology.
Trypanosoma cruzi, the flagellate protozoan agent of Chagas disease or American trypanosomiasis, is unable to synthesize sialic acids de novo. Mucins and trans-sialidase (TS) are substrate and enzyme, respectively, of the glycobiological system that scavenges sialic acid from the host in a crucial interplay for T. cruzi life cycle. The acquisition of the sialyl residue allows the parasite to avoid lysis by serum factors and to interact with the host cell. A major drawback to studying the sialylation kinetics and turnover of the trypomastigote glycoconjugates is the difficulty to identify and follow the recently acquired sialyl residues. To tackle this issue, we followed an unnatural sugar approach as bioorthogonal chemical reporters, where the use of azidosialyl residues allowed identifying the acquired sugar. Advanced microscopy techniques, together with biochemical methods, were used to study the trypomastigote membrane from its glycobiological perspective. Main sialyl acceptors were identified as mucins by biochemical procedures and protein markers. Together with determining their shedding and turnover rates, we also report that several membrane proteins, including TS and its substrates, both glycosylphosphatidylinositol-anchored proteins, are separately distributed on parasite surface and contained in different and highly stable membrane microdomains. Notably, labeling for α(1,3)Galactosyl residues only partially colocalize with sialylated mucins, indicating that two species of glycosylated mucins do exist, which are segregated at the parasite surface. Moreover, sialylated mucins were included in lipid-raft-domains, whereas TS molecules are not. The location of the surface-anchored TS resulted too far off as to be capable to sialylate mucins, a role played by the shed TS instead. Phosphatidylinositol-phospholipase-C activity is actually not present in trypomastigotes. Therefore, shedding of TS occurs via microvesicles instead of as a fully soluble form
Transcription of toll-like receptors 2, 3, 4 and 9, FoxP3 and Th17 cytokines in a susceptible experimental model of canine Leishmania infantum infection
Canine leishmaniosis (CanL) due to Leishmania infantum is a chronic zoonotic systemic disease resulting from complex interactions between protozoa and the canine immune system. Toll-like receptors (TLRs) are essential components of the innate immune system and facilitate the early detection of many infections. However, the role of TLRs in CanL remains unknown and information describing TLR transcription during infection is extremely scarce. The aim of this research project was to investigate the impact of L. infantum infection on canine TLR transcription using a susceptible model. The objectives of this study were to evaluate transcription of TLRs 2, 3, 4 and 9 by means of quantitative reverse transcription polymerase chain reaction (qRT-PCR) in skin, spleen, lymph node and liver in the presence or absence of experimental L. infantum infection in Beagle dogs. These findings were compared with clinical and serological data, parasite densities in infected tissues and transcription of IL-17, IL-22 and FoxP3 in different tissues in non-infected dogs (n = 10), and at six months (n = 24) and 15 months (n = 7) post infection. Results revealed significant down regulation of transcription with disease progression in lymph node samples for TLR3, TLR4, TLR9, IL-17, IL-22 and FoxP3. In spleen samples, significant down regulation of transcription was seen in TLR4 and IL-22 when both infected groups were compared with controls. In liver samples, down regulation of transcription was evident with disease progression for IL-22. In the skin, upregulation was seen only for TLR9 and FoxP3 in the early stages of infection. Subtle changes or down regulation in TLR transcription, Th17 cytokines and FoxP3 are indicative of the silent establishment of infection that Leishmania is renowned for. These observations provide new insights about TLR transcription, Th17 cytokines and Foxp3 in the liver, spleen, lymph node and skin in CanL and highlight possible markers of disease susceptibility in this model
TLR9 activation dampens the early inflammatory response to paracoccidioides brasiliensis, Impacting host survival
Background: Paracoccidioides brasiliensis causes paracoccidioidomycosis, one of the most prevalent systemic mycosis in
Latin America. Thus, understanding the characteristics of the protective immune response to P. brasiliensis is of interest, as it
may reveal targets for disease control. The initiation of the immune response relies on the activation of pattern recognition
receptors, among which are TLRs. Both TLR2 and TLR4 have been implicated in the recognition of P. brasiliensis and
regulation of the immune response. However, the role of TLR9 during the infection by this fungus remains unclear.J.F. Menino was supported by a grant from Fundacao para a Ciencia e Tecnologia (FCT), Portugal (SFRH/BD/33446/2008). This work was supported by a grant from FCT (PTDC/BIA-MIC/108309/2008). M. Saraiva is a Ciencia 2007 fellow and M. Sturme is a Ciencia 2008 fellow. We would also like to thank FAPESP (Fundacao para Amparo a Pesquisa do Estado de Sao Paulo) and CNPq (Conselho Nacional de Desenvolvimento Cientifico e Tecnologico) for financial support. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
Identification of a Novel Calotropis procera Protein That Can Suppress Tumor Growth in Breast Cancer through the Suppression of NF-κB Pathway
10.1371/journal.pone.0048514PLoS ONE712
Reaction and colonization of common bean genotypes by Curtobacterium flaccumfaciens pv. Flaccumfaciens
Bacterial wilt is one of the main diseases of common beans and the use of cultivars with some level of resistance is fundamental for an adequate disease management. The reaction of 54 common bean genotypes to Curtobacterium flaccumfaciens pv. flaccumfaciens (Cff) was evaluated, and the colonization of cultivars and obstruction of primary xylem vessels at the petiole base were assessed. In greenhouse and laboratory tests, resistance was detected in the cultivars IAC Diplomata, IAC Alvorada, IAC Imperador, IPR Corujinha, and IPR Tangará, and in the lines P5-4-4-1 and C4-5-4-1-2. The Cff colonization rate was also slower in the resistant cultivars (IAC Diplomata, IAC Carioca Tybatã, and IAC Carioca Pyatã) and the percentage of obstruction of primary xylem vessels at the petiole base lower than in the susceptible cultivars (IAC Carioca and Pérola).A murcha-de-curtobacterium é umas principais doenças do feijoeiro e o uso de cultivares com níveis de resistência é fundamental para o manejo adequado da doença. A reação de 54 genótipos de feijoeiro comum a um isolado de Curtobacterium flaccumfaciens pv. flaccumfaciens (Cff) foi avaliada, assim como a colonização de cultivares e a obstrução de vasos de xilema primário da base de pecíolos de plantas inoculadas foram quantificadas. Ensaios conduzidos em casa-de-vegetação e laboratório evidenciaram resistência nas cultivares IAC Diplomata, IAC Alvorada, IAC Imperador, IPR Corujinha e IPR Tangará e nas linhagens P5-4-4-1 e C4-5-4-1-2. Uma menor velocidade de colonização por Cff também foi evidenciada nas cultivares resistentes (IAC Diplomata, IAC Carioca Tybatã e IAC Carioca Pyatã), assim como uma menor porcentagem de obstrução dos vasos de xilema primários na base de pecíolos, em comparação às cultivares suscetíveis (IAC Carioca e Pérola).Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Instituto Agronômico de CampinasInstituto Agronômico do ParanáUNESP Faculdade de Ciências Agronômicas Departamento de Proteção Vegeta
Approaches in biotechnological applications of natural polymers
Natural polymers, such as gums and mucilage, are biocompatible, cheap, easily available and non-toxic materials of native origin. These polymers are increasingly preferred over synthetic materials for industrial applications due to their intrinsic properties, as well as they are considered alternative sources of raw materials since they present characteristics of sustainability, biodegradability and biosafety. As definition, gums and mucilages are polysaccharides or complex carbohydrates consisting of one or more monosaccharides or their derivatives linked in bewildering variety of linkages and structures. Natural gums are considered polysaccharides naturally occurring in varieties of plant seeds and exudates, tree or shrub exudates, seaweed extracts, fungi, bacteria, and animal sources. Water-soluble gums, also known as hydrocolloids, are considered exudates and are pathological products; therefore, they do not form a part of cell wall. On the other hand, mucilages are part of cell and physiological products. It is important to highlight that gums represent the largest amounts of polymer materials derived from plants. Gums have enormously large and broad applications in both food and non-food industries, being commonly used as thickening, binding, emulsifying, suspending, stabilizing agents and matrices for drug release in pharmaceutical and cosmetic industries. In the food industry, their gelling properties and the ability to mold edible films and coatings are extensively studied. The use of gums depends on the intrinsic properties that they provide, often at costs below those of synthetic polymers. For upgrading the value of gums, they are being processed into various forms, including the most recent nanomaterials, for various biotechnological applications. Thus, the main natural polymers including galactomannans, cellulose, chitin, agar, carrageenan, alginate, cashew gum, pectin and starch, in addition to the current researches about them are reviewed in this article.. }To the Conselho Nacional de Desenvolvimento Cientfíico e Tecnológico (CNPq) for fellowships (LCBBC and MGCC) and the Coordenação de Aperfeiçoamento de Pessoal de Nvíel Superior (CAPES) (PBSA). This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and COMPETE 2020 (POCI-01-0145-FEDER-006684) (JAT)
Physical characterisation of an alginate/lysozyme nano-laminate coating and its evaluation on ‘coalho’ cheese shelf life
This work aimed at the characterisation of a nanolaminate
coating produced by the layer-by-layer methodology
and its evaluation on the preservation of ‘Coalho’ cheese.
Initially, five alternate layers of alginate and lysozyme were
assembled in an aminolysed/charged polyethylene terephthalate
(A/C PET) and physically characterised by UV/VIS
spectroscopy, contact angle, water vapour (WVTR) and oxygen
(OTR) transmission rates and scanning electron microscopy.
Afterwards, the same methodology was used to
apply the nano-laminate coating in ‘Coalho’ cheese and its
shelf life was evaluated during 20 days in terms of mass
loss, pH, lipid peroxidation, titratable acidity and microbial
count. UV/VIS spectroscopy and contact angle analyses
confirmed the layers’ deposition and the successful assembly
of nano-laminate coating on A/C PET surface. The coating
presented WVTR and OTR values of 1.03×10−3 and 1.28×
10−4 g m−2 s−1, respectively. After 20 days, coated cheese
showed lower values of mass loss, pH, lipidic peroxidation,
microorganisms’ proliferation and higher titratable acidity in
comparison with uncoated cheese. These results suggest that
gas barrier and antibacterial properties of alginate/lysozyme
nanocoating can be used to extend the shelf life of ‘Coalho’
cheese.The author Bartolomeu G. de S. Medeiros is recipient of a scholarship from Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES-Brazil). The author Marthyna P. Souza is recipient of a scholarship from Fundacao de Amparo a Ciencia e Tecnologia do Estado de Pernambuco (FACEPE, Brazil) and was recipient of a scholarship from Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES/PDEE-Brazil). The authors Ana C. Pinheiro, Ana I. Bourbon and Miguel A. Cerqueira are recipients of a fellowship (SFRH/BD/48120/2008, SFRH/BD/73178/2010 and SFRH/BPD/72753/2010, respectively), supported by Fundacao para a Ciencia e Tecnologia, POPH-QREN and FSE (FCT, Portugal). Maria G. Carneiro-da-Cunha express is gratitude to the Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) for research grant. The present work was supported by CAPES/PROCAD/NF/1415/2007. The support of EU Cost Action FA0904 is gratefully acknowledged
Search for New Physics Using Quaero: A General Interface to - D0 Event Data
We describe Quaero, a method that i) enables the automatic optimization of searches for physics beyond the standard model, and ii) provides a mechanism for making high energy collider data generally available. We apply Quaero to searches for standard model WW, ZZ, and ttbar production, and to searches for these objects produced through a new heavy resonance. Through this interface, we make three data sets collected by the D0 experiment at sqrt(s)=1.8 TeV publicly available
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