442 research outputs found
Parapsaenythia inornata sp.n. do noroeste do Brasil (Hymenoptera, Apoidea, Andrenidae)
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
Variation and genetic structure of Melipona quadrifasciata Lepeletier (Hymenoptera, Apidae) populations based on ISSR pattern
For a study of diversity and genetic structuring in Melipona quadrifasciata, 61 colonies were collected in eight locations in the state of Minas Gerais, Brazil. By means of PCR analysis, 119 ISSR bands were obtained, 80 (68%) being polymorphic. He and H B were 0.20 and 0.16, respectively. Two large groups were obtained by the UPGMA method, one formed by individuals from Januária, Urucuia, Rio Vermelho and Caeté and the other by individuals from São João Del Rei, Barbacena, Ressaquinha and Cristiano Otoni. The Φst and θB values were 0.65 and 0.58, respectively, thereby indicating high population structuring. UPGMA grouping did not reveal genetic structuring of M. quadrifasciata in function of the tergite stripe pattern. The significant correlation between dissimilarity values and geographic distances (r = 0.3998; p < 0.05) implies possible geographic isolation. The genetic differentiation in population grouping was probably the result of an interruption in gene flow, brought about by geographic barriers between mutually close geographical locations. Our results also demonstrate the potential of ISSR markers in the study of Melipona quadrifasciata population structuring, possibly applicable to the studies of other bee species
Genetic analysis of Melipona quadrifasciata Lep. (Hymenoptera: Apidae, Meliponinae) with RAPD markers
Effect of chitosan essential oil films on the storage-keeping quality of pork meat products
Edible films based on chitosan were prepared, with
and without basil or thyme essential oils, with the aim of
assessing their protective ability against lipid oxidation and
their antimicrobial activity. Chitosan films had good oxygenbarrier
properties, which were worsened by essential oil addition,
especially when the film equilibrium moisture content
increased. Due to the oxygen-barrier effect, all the films
effectively protected pork fat from oxidation, in comparison
to unprotected samples. In spite of the worsening of the
oxygen-barrier properties, the films with essential oils were
more effective than those of pure chitosan, which points to the
chemical action of specific antioxidant compounds of the oils.
Films were effective to control microbial growth in minced
pork meat, although the incorporation of essential oils did not
improve their antimicrobial activity. Throughout the storage,
the films led to colour changes in minced pork meat associated
with the conversion of myoglobin into metmyoglobin due to
the reduction of the oxygen availability.The authors acknowledge the financial support provided by the Universitat Politecnica de Valencia (PAID-06-09-2834), Generalitat Valenciana (GV/2010/082) and Ministerio de Educacion y Ciencia (AGL2010-20694). Author J. Bonilla is deeply grateful to Generalitat Valenciana for a Santiago Grisolia Grant.Bonilla Lagos, MJ.; Vargas, M.; Atarés Huerta, LM.; Chiralt Boix, MA. (2014). Effect of chitosan essential oil films on the storage-keeping quality of pork meat products. Food and Bioprocess Technology. 7(8):2443-2450. https://doi.org/10.1007/s11947-014-1329-3S2443245078ASTM D3985. (1995). Standard test method for oxygen gas transmission rate through plastic films and sheeting using a coulometric sensor. West Conshohocken: American Society for Testing and Materials.Atarés, L., Pérez-Masiá, R., & Chiralt, A. (2011). The role of some antioxidants in the HPMC film properties and lipid protection in coated toasted almonds. 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Changes in membrane fatty acids composition of microbial cells induced by addiction of thymol, carvacrol, limonene, cinnamaldehyde and eugenol in the growing media. Journal of Agricultural and Food Chemistry, 54, 2745–2749.Di Pierro, P., Sorrentino, A., Mariniello, L., Giosafatto, C. V. L., & Porta, R. (2011). Chitosan/whey protein film as active coating to extend Ricotta cheese shelf-life. LWT--Food Science and Technology, 44, 2324–2327.Fabra, M. J., Talens, P., Gavara, R., & Chiralt, A. (2012). Barrier properties of sodium caseinate films as affected by lipid composition and moisture content. Journal of Food Engineering, 109(3), 372–379.Gaysinsky, S., Davidson, P. M., Bruce, B. D., & Weiss, J. (2005). Growth inhibition of E. Coli O157:H7 and Listeria monocytogenes by carvacrol and eugenol encapsulated in surfactant micelles. Journal of Food Protection, 68, 2559–2566.Govaris, A., Botsoglou, E., Sergelidis, D., & Chatzopoulou, P. D. (2011). 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Terms of reference for the mediterranean tuna habitat observatory initiative
[EN] We present the Terms of Reference for a case study on a Mediterranean eco-region focusing on the environmental component of the Ecosystem Report Card. The objective of this case study is to describe and monitor the variability of environmental processes in the Mediterranean Sea that affect the ecology of large pelagic fishes, with a particular attention on tunas, and the possible role of climate change on this variability. Here we define the objectives and activities of the initiative, the participant roles, primary indicators and the methodological approach[FR] Ce document présente les termes de référence d’une étude de cas sur une écorégion méditerranéenne consacrée à la composante environnementale de la fiche informative sur les écosystèmes. L'objectif de cette étude de cas est de décrire et de suivre la variabilité des processus environnementaux en mer Méditerranée qui affectent l'écologie des grands poissons pélagiques, en accordant une attention particulière aux thonidés, et de déterminer le rôle possible du changement climatique sur cette variabilité. Nous définissons ici les objectifs et les activités de l'initiative, les rôles des participants, les indicateurs primaires et l'approche méthodologique.[ES] En el documento se presentan los términos de referencia para un estudio de caso sobre una ecorregión mediterránea centrado en el componente medioambiental de la ficha informativa sobre ecosistemas. El objetivo de este estudio de caso es describir y hacer un seguimiento de la variabilidad de los procesos medioambientales en el mar Mediterráneo que afectan a la ecología de los grandes peces pelágicos, con especial atención a los túnidos, y el posible papel del cambio climático en esta variabilidad. A continuación, se definen los objetivos y actividades de la iniciativa, las funciones de los participantes, los indicadores principales y el enfoque metodológico.Peer reviewe
Analysis of isoflavones and flavonoids in human urine by UHPLC
A rapid, ultra high-performance liquid chromatographic (UHPLC) method has been developed and validated for simultaneous identification and analysis of the isoflavones genistein, daidzein, glycitin, puerarin, and biochanin A, and the flavonoids (±)-catechin, (−)-epicatechin, rutin, hesperidin, neohesperidin, quercitrin, and hesperetin in human urine. Urine samples were incubated with β-glucuronidase/sulfatase. UHPLC was performed with a Hypersil Gold (50 × 2.1 mm, 1.9 μm) analytical column. Elution was with a gradient prepared from aqueous trifluoroacetic acid (0.05%) and acetonitrile. UV detection was performed at 254 and 280 nm. The calibration curves were indicative of good linearity (r2 ≥ 0.9992) in the range of interest for each analyte. LODs ranged between 15.4 and 107.0 ng mL−1 and 3.9 and 20.4 ng mL−1 for flavonoids and isoflavones, respectively. Intra-day and inter-day precision (C.V., %) was less than 3.9% and 3.8%, respectively, and accuracy was between 0.03% and 5.0%. Recovery was 70.35–96.58%. The method is very rapid, simple, and reliable, and suitable for pharmacokinetic analysis. It can be routinely used for simultaneous determination of these five isoflavones and seven flavonoids in human urine. The method can also be applied to studies after administration of pharmaceutical preparations containing isoflavones and flavonoids to humans
Properties of an alkali-thermo stable xylanase from Geobacillus thermodenitrificans A333 and applicability in xylooligosaccharides generation
An extracellular thermo-alkali-stable and cellulase-free xylanase from Geobacillus thermodenitrificans A333 was purified to homogeneity by ion exchange and size exclusion chromatography. Its molecular mass was 44 kDa as estimated in native and denaturing conditions by gel filtration and SDS-PAGE analysis, respectively. The xylanase (GtXyn) exhibited maximum activity at 70 °C and pH 7.5. It was stable over broad ranges of temperature and pH retaining 88 % of activity at 60 °C and up to 97 % in the pH range 7.5–10.0 after 24 h. Moreover, the enzyme was active up to 3.0 M sodium chloride concentration, exhibiting at that value 70 % residual activity after 1 h. The presence of other metal ions did not affect the activity with the sole exceptions of K+ that showed a stimulating effect, and Fe2+, Co2+ and Hg2+, which inhibited the enzyme. The xylanase was activated by non-ionic surfactants and was stable in organic solvents remaining fully active over 24 h of incubation in 40 % ethanol at 25 °C. Furthermore, the enzyme was resistant to most of the neutral and alkaline proteases tested. The enzyme was active only on xylan, showing no marked preference towards xylans from different origins. The hydrolysis of beechwood xylan and agriculture-based biomass materials yielded xylooligosaccharides with a polymerization degree ranging from 2 to 6 units and xylobiose and xylotriose as main products. These properties indicate G. thermodenitrificans A333 xylanase as a promising candidate for several biotechnological applications, such as xylooligosaccharides preparation
Proliferative activity in human breast cancer: Ki-67 automated evaluation and the influence of different Ki-67 equivalent antibodies
<p>Abstract</p> <p>Background</p> <p>Ki67 labeling index (Ki67 LI), the percentage Ki67 immunoreactive cells, is a measure of tumor proliferation, with important clinical relevance in breast cancer, and it is extremely important to standardize its evaluation.</p> <p>Aim</p> <p>To test the efficacy of computer assisted image analysis (CAIA) applied to completely digitized slides and to assess its feasibility in routine practice and compare the results obtained using two different Ki67 monoclonal antibodies.</p> <p>Materials and methods</p> <p>315 consecutive breast cancer routinely immunostained for Ki-67 (223 with SP6 and 92 with MM1 antibodies previously examined by an experienced pathologist, have been re-evaluated using Aperio Scanscope Xs.</p> <p>Results</p> <p>Mean human Ki67 LI values were 36%± 14.% and 28% ± 18% respectively for SP6 and MM1 antibodies; mean CAM Ki67 LI values were 31%± 19% and 22% ± 18% respectively for SP6 and MM1. Human and CAIA evaluation are statistically highly correlated (Pearson: 0.859, p<0.0001), although human LI are systematically higher. An interobserver variation study on CAIA performed on 84 cases showed that the correlation between the two evaluations was linear to an excellent degree.</p> <p>Discussion</p> <p>Our study shows that a) CAIA can be easily adopted in routine practice, b) human and CAIA Ki67 LI are highly correlated, although human LI are systematically higher, c) Ki67 LI using different evaluation methods and different antibodies shows important differences in cut-off values.</p
Comparison of Xpert MTB/RIF with Other Nucleic Acid Technologies for Diagnosing Pulmonary Tuberculosis in a High HIV Prevalence Setting: A Prospective Study
In this prospective, real-world cohort study nested within a national screening program for tuberculosis, Lesley Scott and colleagues compare the performance of Xpert MTB/RIF on a single sputum sample with different TB sputum detection technologies
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