Spatial autocorrelation and co-occurrence of six serovarieties of Leptospira in goat herds of the State of Guanajuato, Mexico.

The epidemiological behavior of six Leptospira serovarieties was analyzed by spatial autocorrelation and co-occurrence of leptospirosis, diagnosed in goat herds located in the State of Guanajuato, Mexico. A total of 1650 goat serum samples were analyzed by microscopic agglutination (MAT). True prevalence (Pv) and 95% confidence interval (CI95) were determined. Spatial autocorrelation was calculated using the spdep package, applying the global Moran's I and local Moran's I of Leptospira in Guanajuato. The probabilistic model of co-occurrence was applied using the co-occur package. Seroprevalence in the State was found to be 45.5% (CI95 42.96; 48.06%). The highest registered frequency was for the Icterohemorrhagiae serovar (Pv 34.16%; CI95 31.74, 36.65%), followed by the serovar Hardjo-prajitno (Pv: 6.77%; CI95 5.33, 8.40%). Other serovarieties showed a Pv < 5%. Global spatial autocorrelation, only for the Icterohemorrhagiae serovar, was I > 1, while local Moran's I revealed that five of the six Leptospira serovarieties were spatially correlated. The probabilistic model of co-occurrence detected negative associations between Icterohemorrhagiae and the other serovarieties. The current study demonstrates the presence of Leptospira in goat herds of the State of Guanajuato. The diagnosed serovarieties show an aggregation pattern associated to risk zones and disease-transmitting vectors. Antibody co-occurrence analysis revealed dominance of the Icterohemorrhagiae serovar. A multidisciplinary approach including spatial epidemiology, ecological analyses, and serological vigilance will generate useful information for the prevention and control of leptospirosis in caprine production units.

Bioaccumulation of Metals in Cultured Carp (Cyprinus carpio) from Lake Chapala, Mexico.

Chapala, the largest lake in Mexico, has a great potential for aquaculture and a community of some 2500 fishermen who are interested in this activity. However, diverse reports over the past two decades suggest that the fish there are contaminated with heavy metals, raising concern among consumers. Although more recent scientific studies have clarified that the metal content in the edible parts of fish is below allowable limits, the negative perception persists. The present study, therefore, was designed to evaluate the bioaccumulation of the metals Cu, Zn, Pb, As, and Cd in organs such as the muscles, liver, and gills of carp (Cyprinus carpio) cultured in Lake Chapala, and compared the results to fish cultured in a pond. Results after 473 days of monitoring showed that metal bioaccumulation in the muscles of the carp increased by 1.71, 0.50, and 12.36 µg/kg for Cu, Cd, and Pb, respectively, but Zn and As levels decreased by 7.84 and 131.7 µg/kg, respectively. The livers showed concentrations one or two times higher than the muscles in the case of Pb, Cu, Zn, and Cd. According to these results, the metal concentrations in the edible parts of these fish were below international standards for human consumption, and no significant differences were found between the bioaccumulation patterns in the muscles and livers of the carp cultured in the lake and those raised in the pond, except for Cd and Pb in the liver. Finally, no correlations were found between metal concentrations in the fish and lake sediments.

Lipase, Phospholipase, and Esterase Biosensors (Review).

A biosensor is a device composed by a biological recognition element and a transducer that delivers selective information about a specific analyte. Technological and scientific advances in the area of biology, bioengineering, catalysts, electrochemistry, nanomaterials, microelectronics, and microfluidics have improved the design and performance of better biosensors. Enzymatic biosensors based on lipases, esterases, and phospholipases are valuable analytical apparatus which have been applied in food industry, oleochemical industry, biodegradable polymers, environmental science, and overall the medical area as diagnostic tools to detect cholesterol and triglyceride levels in blood samples. This chapter reviews recent developments and applications of lipase-, esterase-, and phospholipase-based biosensors.

Improvement on the productivity of continuous tequila fermentation by Saccharomyces cerevisiae of Agave tequilana juice with supplementation of yeast extract and aeration.

Agave (Agave tequilana Weber var. azul) fermentations are traditionally carried out employing batch systems in the process of tequila manufacturing; nevertheless, continuous cultures could be an attractive technological alternative to increase productivity and efficiency of sugar to ethanol conversion. However, agave juice (used as a culture medium) has nutritional deficiencies that limit the implementation of yeast continuous fermentations, resulting in high residual sugars and low fermentative rates. In this work, fermentations of agave juice using Saccharomyces cerevisiae were put into operation to prove the necessity of supplementing yeast extract, in order to alleviate nutritional deficiencies of agave juice. Furthermore, continuous fermentations were performed at two different aeration flow rates, and feeding sterilized and non-sterilized media. The obtained fermented musts were subsequently distilled to obtain tequila and the preference level was compared against two commercial tequilas, according to a sensorial analysis. The supplementation of agave juice with air and yeast extract augmented the fermentative capacity of S. cerevisiae S1 and the ethanol productivities, compared to those continuous fermentations non supplemented. In fact, aeration improved ethanol production from 37 to 40 g L(-1), reducing sugars consumption from 73 to 88 g L(-1) and ethanol productivity from 3.0 to 3.2 g (Lh)(-1), for non-aerated and aerated (at 0.02 vvm) cultures, respectively. Supplementation of yeast extract allowed an increase in specific growth rate and dilution rates (0.12 h(-1), compared to 0.08 h(-1) of non-supplemented cultures), ethanol production (47 g L(-1)), reducing sugars consumption (93 g L(-1)) and ethanol productivity [5.6 g (Lh)(-1)] were reached. Additionally, the effect of feeding sterilized or non-sterilized medium to the continuous cultures was compared, finding no significant differences between both types of cultures. The overall effect of adding yeast extract and air to the continuous fermentations resulted in 88 % increase in ethanol productivity. For all cultures, pH was not controlled, reaching low pH values (from 2.6 to 3). This feature suggested a reduced probability of contamination for prolonged continuous cultures and explained why no significant differences were found between continuous cultures fed with sterilized or non-sterilized media. Concentrations of volatile compounds quantified in the distillates (tequila) were in the allowed ranges established by the Mexican regulation of tequila (NOM-006-SCFI-2012, Norma Oficial Mexicana: Bebidas alcohólicas-Tequila-specificaciones, 2012). The preference level of the distillates was similar to that of two well-known commercial tequilas. The results suggested the possibility of implementing this innovative technology on an industrial scale, attaining high productivities and using non-sterilized agave juice.

Fuzzy model-based observers for fault detection in CSTR.

Under the vast variety of fuzzy model-based observers reported in the literature, what would be the properone to be used for fault detection in a class of chemical reactor? In this study four fuzzy model-based observers for sensor fault detection of a Continuous Stirred Tank Reactor were designed and compared. The designs include (i) a Luenberger fuzzy observer, (ii) a Luenberger fuzzy observer with sliding modes, (iii) a Walcott-Zak fuzzy observer, and (iv) an Utkin fuzzy observer. A negative, an oscillating fault signal, and a bounded random noise signal with a maximum value of ±0.4 were used to evaluate and compare the performance of the fuzzy observers. The Utkin fuzzy observer showed the best performance under the tested conditions.

Predicting functional regulatory SNPs in the human antimicrobial peptide genes DEFB1 and CAMP in tuberculosis and HIV/AIDS.

Single nucleotide polymorphisms (SNPs) in transcription factor binding sites (TFBSs) within gene promoter region or enhancers can modify the transcription rate of genes related to complex diseases. These SNPs can be called regulatory SNPs (rSNPs). Data compiled from recent projects, such as the 1000 Genomes Project and ENCODE, has revealed essential information used to perform in silico prediction of the molecular and biological repercussions of SNPs within TFBS. However, most of these studies are very limited, as they only analyze SNPs in coding regions or when applied to promoters, and do not integrate essential biological data like TFBSs, expression profiles, pathway analysis, homotypic redundancy (number of TFBSs for the same TF in a region), chromatin accessibility and others, which could lead to a more accurate prediction. Our aim was to integrate different data in a biologically coherent method to analyze the proximal promoter regions of two antimicrobial peptide genes, DEFB1 and CAMP, that are associated with tuberculosis (TB) and HIV/AIDS. We predicted SNPs within the promoter regions that are more likely to interact with transcription factors (TFs). We also assessed the impact of homotypic redundancy using a novel approach called the homotypic redundancy weight factor (HWF). Our results identified 10 SNPs, which putatively modify the binding affinity of 24 TFs previously identified as related to TB and HIV/AIDS expression profiles (e.g. KLF5, CEBPA and NFKB1 for TB; FOXP2, BRCA1, CEBPB, CREB1, EBF1 and ZNF354C for HIV/AIDS; and RUNX2, HIF1A, JUN/AP-1, NR4A2, EGR1 for both diseases). Validating with the OregAnno database and cell-specific functional/non functional SNPs from additional 13 genes, our algorithm performed 53% sensitivity and 84.6% specificity to detect functional rSNPs using the DNAseI-HUP database. We are proposing our algorithm as a novel in silico method to detect true functional rSNPs in antimicrobial peptide genes. With further improvement, this novel method could be applied to other promoters in order to design probes and to discover new drug targets for complex diseases.

Monitoring lipase/esterase activity by stopped flow in a sequential injection analysis system using p-nitrophenyl butyrate.

Lipases and esterases are biocatalysts used at the laboratory and industrial level. To obtain the maximum yield in a bioprocess, it is important to measure key variables, such as enzymatic activity. The conventional method for monitoring hydrolytic activity is to take out a sample from the bioreactor to be analyzed off-line at the laboratory. The disadvantage of this approach is the long time required to recover the information from the process, hindering the possibility to develop control systems. New strategies to monitor lipase/esterase activity are necessary. In this context and in the first approach, we proposed a lab-made sequential injection analysis system to analyze off-line samples from shake flasks. Lipase/esterase activity was determined using p-nitrophenyl butyrate as the substrate. The sequential injection analysis allowed us to measure the hydrolytic activity from a sample without dilution in a linear range from 0.05-1.60 U/mL, with the capability to reach sample dilutions up to 1000 times, a sampling frequency of five samples/h, with a kinetic reaction of 5 min and a relative standard deviation of 8.75%. The results are promising to monitor lipase/esterase activity in real time, in which optimization and control strategies can be designed.

Current status of circulating protein biomarkers to aid the early detection of lung cancer.

Considerable efforts have been undertaken to produce an effective screening method to reduce lung cancer mortality. Imaging tools such as low-dose computed tomography has shown an increase in the detection of early disease and a reduction in the rate of death. This screening modality has, however, several limitations, such as overdiagnosis and a high rate of false positives. Therefore, new screening methods, such as the use of circulating protein biomarkers, have emerged as an option that could complement imaging studies. In this review, current imaging techniques applied to lung cancer screening protocols are presented, as well as up-to-date status of circulating protein biomarker panels that may improve lung cancer diagnosis. Additionally, diverse statistical and artificial intelligence tools applied to the design and optimization of these panels are discussed along with the presentation of two commercially available blood tests recently developed to help detect lung cancer early.

Simultaneous saccharification and fermentation of Agave tequilana fructans by Kluyveromyces marxianus yeasts for bioethanol and tequila production.

Agave tequilana fructans (ATF) constitute a substrate for bioethanol and tequila industries. As Kluyveromyces marxianus produces specific fructanases for ATF hydrolysis, as well as ethanol, it can perform simultaneous saccharification and fermentation. In this work, fifteen K. marxianus yeasts were evaluated to develop inoculums with fructanase activity on ATF. These inoculums were added to an ATF medium for simultaneous saccharification and fermentation. All the yeasts, showed exo-fructanhydrolase activity with different substrate specificities. The yeast with highest fructanase activity in the inoculums showed the lowest ethanol production level (20 g/l). Five K. marxianus strains were the most suitable for the simultaneous saccharification and fermentation of ATF. The volatile compounds composition was evaluated at the end of fermentation, and a high diversity was observed between yeasts, nevertheless all of them produced high levels of isobutyl alcohol. The simultaneous saccharification and fermentation of ATF with K. marxianus strains has potential for industrial application.

Lipase and phospholipase biosensors: a review.

Recent advances in the field of biology, electronics, and nanotechnology have improved the development of biosensors. A biosensor is a device composed of a biological recognition element and a sensor element. Biosensor applications are becoming increasingly important in areas such as biotechnology, pharmaceutics, food, and environment. Lipases and phospholipases are enzymes which have been used widely in food industry, oleochemical industry, biodegradable polymers, detergents, and other applications. In the medical industry, lipases and phospholipases are used as diagnostic tools to detect triglycerides, cholesterol, and phospholipids levels in blood samples. Therefore, the development of lipase and phospholipase biosensors is of paramount importance in the clinical area. This chapter introduces the reader into the preliminaries of biosensor and reviews recent developments of lipase and phospholipase biosensors.

Effect of pH, aeration and feeding non-sterilized agave juice in a continuous agave juice fermentation.

BACKGROUND: Continuous cultures have been used since the 1950s in beer and wine fermentations due to their higher productivities compared to traditional batch systems; nevertheless, the tequila industry has not taken advantage of the possible improvements that continuous fermentations could offer. In this work, the effect of pH, aeration and feeding of non-sterilized medium, on the fermentative capability of two Saccharomyces cerevisiae strains (S1 and S2) cultured in continuous fermentation, using agave juice as the fermentation medium, were studied. RESULTS: In continuous cultures, the control of the medium pH (set point at 4) did not have a significant effect on fermentation efficiency compared to fermentations in which the pH was not controlled (pH 2.5 +/- 0.3). Conversely, aeration of the cultures of both strains improved biomass production and consumption of reducing sugars and ammonium. The aeration also significantly augmented ethanol production only for S1 cultures (P < 0.05). Furthermore, the feeding of medium, either sterilized or not, did not show significant differences on the production of ethanol for S1 cultures. Higher concentrations of acetoin, succinic acid and diacetyl were found in the cultures fed with non-sterilized medium. CONCLUSIONS: Compared to S2, S1 has a better fermentative performance in continuous non-sterilized medium fermentations. Not controlling the pH during the cultures could prevent the possibility of microbial contamination as a result of the extreme medium acidity (pH 2.5 +/- 0.3). This work showed the possibility of scaling up agave juice continuous fermentation feeding non-sterilized medium with no control of pH.

Epidemiological study of Brucellosis in cattle, immunized with Brucella abortus RB51 vaccine in endemic zones.

In this study the behavior of the Brucella abortus RB51 vaccine was evaluated in bovine herds, with different prevalence of Brucellosis. A prospective longitudinal study was made, in two dairies, one of low prevalence (9%) with 538 cows, and the other of high prevalence (15%) with 612 cows. The cattle were vaccinated twice 90 days apart with RB51 at a dose of 1×10(9)cfu/ml. The monthly incidence was determined during 660 days of observation. In the low prevalence dairy, all positive animals were eliminated as soon as they were diagnosed as positive and in this herd the number of new cases decreased to less than 1% between days 120, and day 660. In the dairy with high prevalence, positive cows were not eliminate resulting in the herd increasing its incidence by the end of the first year. Once positive animals were eliminated the incidence diminishes by day 660 to less of 1%. The odds ratio (OR) in the group of cows with abortion history, in the low prevalence dairy, was of 4.5 (1.2; 16.6), in the dairy ranch with high prevalence it presented an OR of 3.6 (1.5; 8.5). The conclusion from this study was that in brucellosis endemic zones, vaccination with RB51 by itself is not enough to control disease. It is mandatory that the initial elimination of all positive cows at the time of vaccination, the continued elimination of all new positive animals be adhered to for long periods of time.