1,265 research outputs found
Bee Pollination Highly Improves Oil Quality in Sunflower
Sunflower is a pollinator-dependent crop and one of the most cultivated oilseeds in the world, supporting important sectors of the agricultural industry, such as the food supply, because it is an important source of vitamin E and unsaturated fatty acids for human health. Although it is well stablished that bee pollination improves sunflower seed set, it is still unknown if pollinators influence the nutritional composition. Considering the economic importance of sunflowers for several Brazilian agricultural sectors, the aim of this study was to evaluate the effect of the bee community for (1) achene quality (weight and nutritional composition) and (2) market value. Exclusion experiments were performed with hybrid sunflowers and showed that bee pollination enhanced the achene weight by 91 %, the levels of vitamin E by 45 % and unsaturated fatty acids by 0.3 %. Also, it was estimated that due to the pollination services provided by bees, the grower of the sunflower cultivar used in this study nearly duplicates the sale value of the achenes per hectare of cultivated area. Thus, the current study highlights the importance of bees as providers of cross- and self-pollination to nutritional quality of sunflower achenes and provides useful baseline figures to further evaluations of the effects of pollinators on human diets and health
Cyclodextrins as Supramolecular Recognition Systems: Applications in the Fabrication of Electrochemical Sensors
Supramolecular chemistry, although focused mainly on noncovalent intermolecular and intramolecular interactions, which are considerably weaker than covalent interactions, can be employed to fabricate sensors with a remarkable affinity for a target analyte. In this review the development of cyclodextrin-based electrochemical sensors is described and discussed. Following a short introduction to the general properties of cyclodextrins and their ability to form inclusion complexes, the cyclodextrin-based sensors are introduced. This includes the combination of cyclodextrins with reduced graphene oxide, carbon nanotubes, conducting polymers, enzymes and aptamers, and electropolymerized cyclodextrin films. The applications of these materials as chiral recognition agents and biosensors and in the electrochemical detection of environmental contaminants, biomolecules and amino acids, drugs and flavonoids are reviewed and compared. Based on the papers reviewed, it is clear that cyclodextrins are promising molecular recognition agents in the creation of electrochemical sensors, chiral sensors, and biosensors. Moreover, they have been combined with a host of materials to enhance the detection of the target analytes. Nevertheless, challenges remain, including the development of more robust methods for the integration of cyclodextrins into the sensing unit
Phylogenetic and functional diversity of metagenomic libraries of phenol degrading sludge from petroleum refinery wastewater treatment system
In petrochemical refinery wastewater treatment plants (WWTP), different concentrations of pollutant compounds are received daily in the influent stream, including significant amounts of phenolic compounds, creating propitious conditions for the development of particular microorganisms that can rapidly adapt to such environment. In the present work, the microbial sludge from a refinery WWTP was enriched for phenol, cloned into fosmid vectors and pyrosequenced. The fosmid libraries yielded 13,200 clones and a comprehensive bioinformatic analysis of the sequence data set revealed a complex and diverse bacterial community in the phenol degrading sludge. The phylogenetic analyses using MEGAN in combination with RDP classifier showed a massive predominance of Proteobacteria, represented mostly by the genera Diaphorobacter, Pseudomonas, Thauera and Comamonas. The functional classification of phenol degrading sludge sequence data set generated by MG-RAST showed the wide metabolic diversity of the microbial sludge, with a high percentage of genes involved in the aerobic and anaerobic degradation of phenol and derivatives. In addition, genes related to the metabolism of many other organic and xenobiotic compounds, such as toluene, biphenyl, naphthalene and benzoate, were found. Results gathered herein demonstrated that the phenol degrading sludge has complex phylogenetic and functional diversities, showing the potential of such community to degrade several pollutant compounds. This microbiota is likely to represent a rich resource of versatile and unknown enzymes which may be exploited for biotechnological processes such as bioremediation
The Floristic-Holistic Method for Arid, Semiarid, and Subhumid Areas: A Tool for the Revaluation of Floristic Diversity, Conservation, and Protection of the Ecosystem
The valorization of methods for comprehensive data collection is one of the fundamental tools to establish concrete bases and is applicable to lines of work in conservation, preservation, and protection of ecosystems. During the last 20 years, from the Botany Laboratory and Herbarium Trelew, we have valued the Floristic-Holistic Method that we have been adapting, for flora surveys. Method is intensively used in some Argentine provinces of arid, semiarid, and subhumid zones of the South American Arid Diagonal (Santa Cruz, Chubut, RÃo Negro, Neuquén, Mendoza, and arid islands of the Patagonian Atlantic coast). This revaluation focuses its importance on not only providing information on ecological parameters (bare soil, topsoil, living plant cover, and dead plant cover), richness, equitability, and floristic diversity, but also on status, conservation, botanical types, biological forms, adaptations, plant density, percentages of protected species, potential invasions of exotic species, forage productivity, and animal receptivity. The information is comprehensive and adaptable to different situations, applicable to different plant associations, types of terrain, and landscape units (open and closed mount, shrubby steppes, subshrubs, grasses, wastelands, rocky fields, peladales, and all kinds of modified areas). The method thus holistically conceptualizes ecosystem goods and services, allowing their study at different scales
Evaluation of MCM-2 Expression in TMA Cervical Specimens
Background:Minichromosome maintenance proteins (MCM) are highly expressed in actively replicating cells. The need for
biological markers for cervical carcinoma and its precursor lesions is emerging. Our main aim was to determine the
immunohistochemical expression of MCM-2 in HIV-positive and -negative dysplastic cervical specimens.
Methods:Immunohistochemical analysis of MCM-2 was performed in a total of 352 cervical TMA specimens of normal
control, low-grade CIN, high-grade CIN and invasive tumor. 38 specimens were from HIV-positive women. A receiver
operating characteristic (ROC) curve was constructed to determine the best cutoff to diagnose high-grade CIN and invasive
cervical cancer.
Results:In the progression from normal epithelium to high-grade CIN and invasive tumor we found significant differences
in the MCM-2 expression (p,0.05). Based on the ROC curve of 80% with an area under the curve (AUC) of 0.78, expression of
MCM-2 to diagnose high-grade CIN and invasive tumor resulted in sensitivity of 81%, specificity of 66%, a positive predictive
value (PPV) of 86% and a negative predictive value (NPV) of 57%. HIV-positive cervices revealed a decreasing expression of
MCM-2 in both LGCIN and HGCIN compared with HIV-negative specimens (p,0.0001).
Conclusions:The present study suggests that immunohistochemical MCM-2 may not be a promising biomarker for
diagnosing high-grade CIN and invasive cance
Risk factors for treatment delay in pulmonary tuberculosis in Recife, Brazil
BACKGROUND: Tuberculosis is still a great challenge to public health in Brazil and worldwide. Early detection followed by effective therapy is extremely important in controlling the disease. Recent studies have investigated reasons for delays in treatment, but there is no agreed definition of what constitutes an "acceptable" delay. This study investigates factors associated with total delay in treatment of tuberculosis. METHODS: A cohort of adult cases of pulmonary tuberculosis diagnosed over a two-year period was studied. Patients were interviewed on entry, reporting the duration of symptoms before the start of treatment, and sputum and blood samples were collected. It was decided that sixty days was an acceptable total delay. Associations were investigated using univariable and multivariable analysis and the population attributable fraction was estimated. RESULTS: Of 1105 patients, 62% had a delay of longer than 60 days. Age, sex, alcoholism and difficulty of access were not associated with delays, but associations were found in the case of unemployment, having given up smoking, having lost weight and being treated in two of the six health districts. The proportion attributable to: not being an ex-smoker was 31%; unemployment, 18%; weight loss, 12%, and going to the two worst health districts, 25%. CONCLUSION: In this urban area, delays seem to be related to unemployment and general attitudes towards health. Although they reflect the way health services are organized, delays are not associated with access to care
Clinical Characteristics and Treatment Patterns of Children and Adults With IgA Nephropathy or IgA Vasculitis: Findings From the CureGN Study
Introduction:
The Cure Glomerulonephropathy Network (CureGN) is a 66-center longitudinal observational study of patients with biopsy-confirmed minimal change disease, focal segmental glomerulosclerosis, membranous nephropathy, or IgA nephropathy (IgAN), including IgA vasculitis (IgAV). This study describes the clinical characteristics and treatment patterns in the IgA cohort, including comparisons between IgAN versus IgAV and adult versus pediatric patients.
Methods:
Patients with a diagnostic kidney biopsy within 5 years of screening were eligible to join CureGN. This is a descriptive analysis of clinical and treatment data collected at the time of enrollment.
Results:
A total of 667 patients (506 IgAN, 161 IgAV) constitute the IgAN/IgAV cohort (382 adults, 285 children). At biopsy, those with IgAV were younger (13.0 years vs. 29.6 years, P < 0.001), more frequently white (89.7% vs. 78.9%, P = 0.003), had a higher estimated glomerular filtration rate (103.5 vs. 70.6 ml/min per 1.73 m2, P < 0.001), and lower serum albumin (3.4 vs. 3.8 g/dl, P < 0.001) than those with IgAN. Adult and pediatric individuals with IgAV were more likely than those with IgAN to have been treated with immunosuppressive therapy at or prior to enrollment (79.5% vs. 54.0%, P < 0.001).
Conclusion:
This report highlights clinical differences between IgAV and IgAN and between children and adults with these diagnoses. We identified differences in treatment with immunosuppressive therapies by disease type. This description of baseline characteristics will serve as a foundation for future CureGN studies
Current and Future Applications of the GEOS-5 Aerosol Modeling System
The presentation summarizes current and proposed activities for the GEOS-5 aerosol modeling system. Activities discussed include (i) forecasting and event simulation, (ii) observation simulation, (iii) aerosol-chemistry-climate applications, and (iv) future activities. The document was presented at the 2013 AEROCENTER Annual Meeting held at the GSFC Visitors Center May 31, 2013. The Organizers of the meeting are posting the talks to the public Aerocenter website, after the meeting
Pulmonar recruitment in acute respiratory distress syndrome. What is the best strategy?
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