O Mediterrâneo enquanto metáfora da mestiçagem: Novas leituras sobre o modelo europeu na América Latina dos anos 1920

After the First World War, we can observe in the Latin American society a strong transformation in the perception of the Europe as a civilization model. New movements in art and literature start to rethink the National Identities in Latin America and in the whole subcontinent born a criticism against the importation of European civility concepts. This process can be deeply analyzed in Mistral’s writings that shows us the continental transformation through the Mediterranean metaphor: between a Latin space and a space of miscegenation. In Mistral’s narratives, we can notice two kinds of analytical movements between North and South relations: when the writer talks about the European contrasts, she talks also about those of the American continent. In this context, the Old World, or its Southern part, shares its Historical experience with the New World to justify the positive perception of the New Latin American men: Multiethnic

A multiattribute utility evaluation of different methods for the detection of enteric protozoa causing diarrhea in AIDS patients

<p>Abstract</p> <p>Background</p> <p>Enteric protozoa and sporozoa have emerged as important opportunistic parasites and can cause fatal infections in AIDS patients. The line of treatment being different for them necessitates an accurate and prompt identification of these to avoid empirical treatment. In this study which is the first of its kind from India we did a comprehensive evaluation of different techniques, comparing them on the basis of the attributes like yield, cost, time taken, expertise and infrastructure. For the first time combination of Calcoflour White and DAPI, a nuclear stain, were used to identify <it>Microsporidia </it>spp. Thus, a diagnostic protocol was devised for rapid, sensitive and cost effective identification of the opportunistic enteric protozoa.</p> <p>Results</p> <p>The organisms isolated from the stool samples of the cases (450 HIV patients) were predominantly <it>Cryptosporidium </it>spp., <it>Microsporidia </it>spp. and <it>Cyclospora </it>spp. Interestingly, the control group (200 relatives of the patients who were HIV negative) showed a high incidence (21%) of <it>Cryptosporidium </it>spp. We found a significant increase in the sensitivity of microscopy in detecting <it>Cryptosporidium </it>spp. and <it>Cyclospora </it>spp. after formol ether concentration. Kinyoun's staining was better compared to Modified safranin staining for <it>Cryptosporidium </it>spp. identification. Although ELISA had a sensitivity of 93.25% and specificity of 97% for <it>Cryptosporidium </it>spp. detection, we ranked Kinyoun's staining better than ELISA because it is not affordable to most of our patients. For detecting <it>Cyclospora cayetanensis</it>, autoflourescence was the easiest and most cost effective method followed by Safranin technique. Combination of Calcoflour White stain and DAPI gave good results for the identification of <it>Microsporidia </it>spp. We assessed the above techniques and graded the attributes in the following descending order: cost effectiveness, sensitivity, ease of use and interpretation, time taken for the procedure and batch testing.</p> <p>Conclusion</p> <p>Thus, we conclude that a combination of minimum three procedures should be carried out for the screening of stool specimens of HIV positive patients. Kinyoun's staining should be made mandatory for every diarrheal stool sample from HIV patients. Also every laboratory should assign its own value to the attributes and apply Multiattribute utility theory or the Analytical hierarchy process to decide the most appropriate methodology.</p

In Silico Targeting of influenza virus haemagglutinin receptor protein using Diosmetin, Tangeritin, and Anthocyanidins as potential drugs

Influenza viruses cause acute respiratory illnesses in birds, humans, and other mammals, and are a major public health concern around the world. Pandemic flu could be caused by an unforeseen human adaptation of an influenza subtype or strain rather than currently circulating influenza viruses. The need for plant metabolites-based new anti-influenza drugs appears to be urgent. Blocking Haemeagglutinin (HA) protein is one of the most appealing drug targets to halt the growth of the virus. The influenza virus can acquire resistance to currently existing therapies, therefore necessitating the development of new medications. The plant's bioactive metabolites, flavanoids are having potential medicinal efficacy. The current study aimed to identify certain flavonoids (Diosmetin, Tangeritin, and Anthocyanidins) that might interact with the HA protein of the influenza virus and help in inhibiting its growth. We used PyRx v0.8 for virtual screening and docking studies. The highest binding affinity docked structures were analyzed using PyMOL and Discovery Studio Visualizer. The present study revealed that these naturally occurring compounds interacted with HA protein, resulting in the minimization of energy in the range of -5.2 to -7.0 kcal/mol. Diosmetin showed the best binding affinity of -7.0Kcal/mol. The molecular binding studies revealed that Diosmetin, Tangeritin, and Anthocyanidins are potential compounds to test against HA protein and can be used to develop effective anti-influenza agents

Synergistic Enzyme Cocktail to Enhance Hydrolysis of Steam Exploded Wheat Straw at Pilot Scale

Multiple enzymes are required for efficient hydrolysis of lignocellulosic biomass and no wild type organism is capable of producing all enzymes in desired levels. In this study, steam explosion of wheat straw was carried out at pilot scale and a synthetic enzyme mixture (EnzMix) was developed by partially replacing the cellulase with critical dosages of commercially available accessory enzymes (β-glucosidase, xylanase and laccase) through central composite design. Highest degree of synergism (DS) was observed with β-glucosidase (1.68) followed by xylanase (1.36). Finally, benchmarking of EnzMix (Celluclast, β-glucosidase and xylanase in a protein ratio of 20.40: 38.43: 41.16, respectively) and other leading commercial enzymes was carried out. Interestingly, hydrolysis improved by 75% at 6 h and 30% at 24 h, respectively in comparison of control. By this approach, 25% reduction in enzyme dosage was observed for obtaining the same hydrolysis yield with opitimized enzyme cocktail. Thus, development of enzyme cocktail is an effective and sustainable approach for high hydrolysis efficiency

Cellulosic ethanol production via consolidated bioprocessing by a novel thermophilic anaerobic bacterium isolated from a Himalayan hot spring

BackgroundCellulose-degrading thermophilic anaerobic bacterium as a suitable host for consolidated bioprocessing (CBP) has been proposed as an economically suited platform for the production of second-generation biofuels. To recognize the overall objective of CBP, fermentation using co-culture of different cellulolytic and sugar-fermenting thermophilic anaerobic bacteria has been widely studied as an approach to achieving improved ethanol production. We assessed monoculture and co-culture fermentation of novel thermophilic anaerobic bacterium for ethanol production from real substrates under controlled conditions.ResultsIn this study, Clostridium sp. DBT-IOC-C19, a cellulose-degrading thermophilic anaerobic bacterium, was isolated from the cellulolytic enrichment cultures obtained from a Himalayan hot spring. Strain DBT-IOC-C19 exhibited a broad substrate spectrum and presented single-step conversion of various cellulosic and hemicellulosic substrates to ethanol, acetate, and lactate with ethanol being the major fermentation product. Additionally, the effect of varying cellulose concentrations on the fermentation performance of the strain was studied, indicating a maximum cellulose utilization ability of 10 g L&minus;1 cellulose. Avicel degradation kinetics of the strain DBT-IOC-C19 displayed 94.6% degradation at 5 g L&minus;1 and 82.74% degradation at 10 g L&minus;1 avicel concentration within 96 h of fermentation. In a comparative study with Clostridium thermocellum DSM 1313, the ethanol and total product concentrations were higher by the newly isolated strain on pretreated rice straw at an equivalent substrate loading. Three different co-culture combinations were used on various substrates that presented two-fold yield improvement than the monoculture during batch fermentation.ConclusionsThis study demonstrated the direct fermentation ability of the novel thermophilic anaerobic bacteria on various cellulosic and hemicellulosic substrates into ethanol without the aid of any exogenous enzymes, representing CBP-based fermentation approach. Here, the broad substrate utilization spectrum of isolated cellulolytic thermophilic anaerobic bacterium was shown to be of potential utility. We demonstrated that the co-culture strategy involving novel strains is efficient in improving ethanol production from real substrate.<br /

Preparation of novel catalyst composition from natural waste for biodiesel production

1054-1060This study presents preparation of a novel, cost effective and recyclable catalyst from natural waste for production of biodiesel. Novel catalyst composition has been developed using combination of seashell and eggshell in complexation with transition metal oxide TiO2 to form A-B-O type metal oxide complex, where A is alkaline metal and B is transition metal. Catalyst composition has been evaluated and a robust cost effective method for biodiesel production is proposed

Propyl gallate and butylated hydroxytoluene influence the accumulation of saturated fatty acids, omega-3 fatty acid and carotenoids in thraustochytrids

Schizochytrium sp. S31 was shown to have potential for production of the functional food ingredients docosahexaenoic acid (DHA) and astaxanthin, with coproduction of biodiesel. Biomass and lipid levels were greater with glycerol than with glucose as carbon source. Addition of propyl gallate or butylated hydroxytoluene to the media resulted in increased biomass and lipid levels, with propyl gallate being the more effective of the two antioxidants. Medium supplementation with propyl gallate at 0.03% and glycerol as the carbon source resulted in enhanced biomass productivity (28.50 g L-1), lipid accumulation (24.87 g L-1) and astaxanthin levels (452.26 &mu;g L-1)

Combination of calcium and magnesium ions prevents substrate inhibition and promotes biomass and lipid production in thraustochytrids under higher glycerol concentration

Effect of calcium and magnesium ions was studied in detail in batch mode in shake flask cultures of two fast growing strains of thraustochytrids (Aurantiochytrium sp. DBTIOC-18 and Schizochytrium sp. DBTIOC-1) for biomass and lipid production. These strains were previously isolated from Indian marine biodiversity. Screening of these two strains on different carbon and nitrogen sources revealed the suitability of glycerol over glucose and sodium nitrate over yeast extract for the cultivation of these strains. The presence of higher concentration of glycerol in the medium inhibited the glycerol utilization by the cell thus resulting in lower biomass and lipid production in both the strains. Supplementing media with calcium and magnesium ions promoted glycerol utilization thus resulted in a substantial rise in volumetric production of biomass (55.12 g L-1, 48.12 g L-1), fatty acid for biodiesel (27.14 g L-1, 22.15 g L-1) and docosahexaenoic acid (14.57 g L-1, 10.12 g L-1) with both strains Aurantiochytrium sp. DBTIOC-18 and Schizochytrium sp. DBTIOC-1, respectively. Growth profile study of these two strains showed further improvement in production of biomass, fatty acid for biodiesel and docosahexaenoic acid when cultures were extended up to 7 days. Finding of this work underlines the importance of calcium and magnesium salts in designing new fermentation strategies to prevent substrate inhibition and achieve high cell density culture under high nutrient concentration especially carbon sources

Optimization of zeaxanthin and β-carotene extraction from Chlorella saccharophila isolated from New Zealand marine waters

Zeaxanthin is an important natural pigment which has found commercial application in food and nutritional supplements. Its potential widespread use requires an easy and effective extraction methodology for obtaining higher yields. Extraction from Chlorella sp. under optimized conditions demonstrated a marked reduction in extraction time (13.48min) compared with a control experiment (30min). The extraction conditions such as solvent/cell dry weight (CDW) ratio, power, pulse, time and their combinations were optimized using response surface methodology (RSM). Almost all the variables were shown significantly (p-value &lt;0.05) affect the carotenoid yield. Significant interaction (p-value &lt;0.05) was observed with a substantial effect on zeaxanthin yield for solvent/CDW ratio and power, as well as power and time, whereas the &beta;-carotene control exhibited significant interaction between solvent/CDW ratio and pulse, as well as between pulse and time. The R 2-value approached unity in both models, demonstrating their accuracy. Data obtained from these interactions were used to construct 3D response plots. Solvent/CDW ratio of 67.38&mu;lmg-1, power 27.82% (total power 500W), pulse length of 19.7s and time 13.48min were found to be the optimized conditions for zeaxanthin (11.2mgg-1) and &beta;-carotene (4.98mgg-1) extraction