Bacterial pathogens are a leading cause of waterborne disease, and may result in gastrointestinal outbreaks worldwide. Inhabitants of the Bassaseachic Falls National Park in Chihuahua, Mexico show ...seasonal gastroenteritis problems. This aim of this study was to detect enteropathogenic microorganisms responsible for diarrheal outbreaks in this area. In 2013, 49 surface water samples from 13 selected sampling sites along the Basaseachi waterfall and its main rivers, were collected during the spring, summer, autumn, and winter seasons. Fecal and total coliform counts were determined using standard methods; the AutoScan-4 system was used for identification of isolates and the antibiotic resistance profile by challenging each organism using 21 antibiotics. Significant differences among seasons were detected, where autumn samples resulted in the highest total (p < 0.05) and fecal (p < 0.001) coliform counts, whereas the lowest total coliform counts were recorded in spring. Significant differences between sampling sites were observed, where samples from sites 6, 8, and 11 had the highest total coliform counts (p < 0.009), whereas samples from site 9 exhibited the lowest one. From the microbiological analysis, 33 bacterial isolates from 13 different sites and four sampling seasons were selected; 53% of isolates were resistant to at least one antibiotic, and 15% exhibited a multidrug resistance (MDB) phenotype. MDB were identified as Klebsiella oxytoca (two out of four identified isolates), Escherichia coli (2/7), and Enterobacter cloacae (1/3). In addition, some water-borne microorganisms exhibited resistance to cefazoline, cefuroxime, ampicillin, and ampicillin-sulbactam. The presence of these microorganisms near rural settlements suggests that wastewater is the contamination source, providing one possible transmission mechanism for diarrheal outbreaks.
New product development projects (NPDP) face different risks that may affect the scheduling. In this article, the purpose was to develop an optimization model to solve the RCPSP in NPDP and obtain a ...robust baseline for the project. The proposed model includes three stages: the identification of the project’s risks, an estimation of activities’ duration, and the resolution of an integer linear program. Two versions of the model were designed and compared in order to select the best one. The first version uses a method to estimate the activities’ duration based on the expected value of the impact of the risks and the second version uses a method based on the judgmental risk analysis process. Finally, the two version of the model were applied to a case study and the best version of the model was identified using a robustness indicator that analyses the start times of the baselines generated.
Macro- and microorganism activities are important for the effectiveness of the slow sand filtration (SSF), where native microorganisms remove contaminants mainly by substrate competition, predation, ...and antagonism. The aim of the present study was to evaluate the addition of the oligodynamic metals iron, copper, and brass, inserted separately into SSF to enhance pollutant removal in water samples. Four laboratory-scale SSFs were built and tested: control, iron, copper, and brass. Water analysis included physicochemical evaluation, total and fecal coliform quantification. An analysis on microbial communities in the SSFs schmutzdecke was achieved by using 16S rRNA amplification, the Illumina MiSeq platform, and the QIIME bioinformatics software. The results demonstrated that inorganic and organic contaminants such as coliforms were removed up to 90%. The addition of metals had no significant effect (p > 0.05) on the other parameters. The microbial community analysis demonstrated different compositions of the SSF with brass-influent, where the eukaryote Streptophyta was predominant (31.4%), followed by the acetic acid bacteria Gluconobacter (24.6%), and Acetobacteraceae (7.7%), these genera were absent in the other SSF treatments. In conclusion, the use of a SSF system can be a low cost alternative to reduce microbial contamination in water and thus reduce gastrointestinal diseases in rural areas.
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In the Project Scheduling Problem (PSP), the solution robustness can be understood as the capacity that a baseline has to support the disruptions generated by unplanned events (risks). A robust ...baseline of the project can be obtained from redundancy based methods, which are considered proactive methods to solve the stochastic project scheduling problem. In this research, three redundancy based methods are evaluated and their performance is compared in terms of robustness. These methods add extra time to the original activities duration in order to face the eventualities that may appear during the project execution. In this article a new indicator to analyze the solution robustness to the Project Scheduling Problem with random duration of activities is proposed. This indicator called Relative Average Deviation (RAD) is defined as the margin of deviation of the activities’ start times in relation to their durations. The RAD is based in a traditional concept that seeks to minimize the value of the differences between the planned start times and the real executed start times. The planned start times were obtained from the project baseline generated by each redundancy based method and the real executed start times were obtained from a simulation process based on Monte Carlo technique. The new indicator was used to evaluate the robustness of three baselines generated by different methods but applied to the same case study. Finally, the results suggest that the Relative Average Deviation (RAD) facilitates the interpretation of the robustness concept because it focuses on analyzing the deviation margin associated with an activity.
Abstract
The aim of this study was to assess the bacterial diversity associated with a corrosive biofilm in a steel pipeline from the Gulf of Mexico used to inject marine water into the oil ...reservoir. Several aerobic and heterotrophic bacteria were isolated and identified by 16S rRNA gene sequence analysis. Metagenomic DNA was also extracted to perform a denaturing gradient gel electrophoresis analysis of ribosomal genes and to construct a 16S rRNA gene metagenomic library. Denaturing gradient gel electrophoresis profiles and ribosomal libraries exhibited a limited bacterial diversity. Most of the species detected in the ribosomal library or isolated from the pipeline were assigned to Proteobacteria (Halomonas spp., Idiomarina spp., Marinobacter aquaeolei, Thalassospira sp., Silicibacter sp. and Chromohalobacter sp.) and Bacilli (Bacillus spp. and Exiguobacterium spp.). This is the first report that associates some of these bacteria with a corrosive biofilm. It is relevant that no sulfate-reducing bacteria were isolated or detected by a PCR-based method. The diversity and relative abundance of bacteria from water pipeline biofilms may contribute to an understanding of the complexity and mechanisms of metal corrosion during marine water injection in oil secondary recovery.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
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•The valorisation of CW a dairy industry wastewater was attained.•CW supplemented with ammonium sulphate supported PHB production.•Enhanced fermentation conditions for PHB production ...by B. subtilis EPAH18 were achieved.•The bioprocess was competitive at a CW feed of 1000 ton/h.
The production of biopolymers such as poly (3-hydroxybutyrate) (PHB) from renewable resources has gained revived attention; although, fermenting media cost affects the production price. Whilst cheese whey (CW) is an alternative source of nutrients it is managed as wastewater in rural dairy factories. Thus, this can serve as a low-cost fermenting media improving the economics of PHB production. The aim of this work is to develop the fermentation conditions for enhanced Bacillus subtilis EPAH18 PHB biosynthesis and evaluate the economics of the bioprocess by process simulation. Shake flask fermentations performed in order to identify improved PHB biosynthesis conditions were obtained at 37 °C, 24 h of fermentation, 200 rpm, 0.5% (w/v) ammonium sulphate and an inoculum of 5% (v/v). PHB biosynthesis was scaled-up to a batch bioreactor where the optimized fermentation conditions were an agitation of 500 rpm, carbon to nitrogen ratio (C/N) of 17.5/1 and pH of 7.6. The highest values of PHB production and yield (YP/S) were 0.54 g/L and 0.057 g/g respectively. The bioprocess was competitive at 1000 ton/h CW feed achieving a PHB production cost of 10.2 US$/kg. It can be concluded that CW could be exploited as a platform for a PHB biorefinery.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In northern Mexico, the distilled spirit sotol with a denomination of origin is made from species of
. The configuration of the volatile metabolites produced during the spontaneous fermentation of
...sp. must is insufficiently understood. In this study, the aim was to investigate the composition of the microbial consortia, describe the variation of volatile metabolites, and relate such profiles with their particular flavor attributes during the fermentation of sotol (
sp.) must. Ascomycota was the phylum of most strains identified with 75% of total abundance. The genus of fermenting yeasts constituted of 101 Pichia strains and 13 Saccharomyces strains. A total of 57 volatile metabolites were identified and grouped into ten classes. The first stage of fermentation was composed of diesel, green, fruity, and cheesy attributes due to butyl 2-methylpropanoate, octan-1-ol, ethyl octanoate, and butanal, respectively, followed by a variation to pungent and sweet descriptors due to 3-methylbutan-1-ol and butyl 2-methylpropanoate. The final stage was described by floral, ethereal-winey, and vinegar attributes related to ethyl ethanimidate, 2-methylpropan-1-ol, and 2-hydroxyacetic acid. Our results improve the knowledge of the variations of volatile metabolites during the fermentation of sotol must and their contribution to its distinctive flavor.
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Objective. To investigate whether sexual assaults are more likely to co‐occur with some types of abuse rather than others in violent intimate relationships. Design. Cross‐sectional study. Setting. A ...self‐administered questionnaire was sent to all Norwegian women's shelters. Population. Women seeking refuge at Norwegian women's shelters in 2002 and 2003. Methods. Sexual assault and experiences of intimate partner violence were measured using the Severity of Violence against Women Scale (SVAWS) and psychological violence was measured using the Psychological Maltreatment of Women Inventory (PMWI). Main outcome measures. Student's t‐test analyses were performed between the mean values of the different acts of reported violence, and linear regression analyses were used to examine the association between sexual violence and the other forms of violence reported. Results. Sexual violence correlated significantly with the other eight categories in SVAWS, and with violence directed at the pregnant woman's abdomen and psychological violence in PMWI. When we adjusted all categories for each other by linear regression analysis, sexual intimate partner violence was significantly associated with hair pulling, arm twisting, spanking or biting, dominance and isolation abuse and violence directed at the pregnant woman's abdomen. Conclusion. Sexual assaults are more likely to co‐occur with some types of physical and psychological violence than with others. This knowledge may be important for improving our understanding of sexual violence in intimate partner relationships and in the efforts to detect intimate partner violence. Bruises, loss of hair and bite marks may suggest that sexual acts were committed against the victim's will.
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Although important advances in treatment strategies have been developed in type 2 diabetes mellitus (T2DM), large gaps exist in achieving glycemic control and preventing complications, particularly ...in low-and middle-income countries, which suggests a potential effect of social determinants of health (SDH, i.e., education level and socioeconomic status). However, few studies have determined the role of SDH and other determinants of health (ODH, i.e., diabetes knowledge and self-care scores) in achieving T2DM goals during effective multidisciplinary interventions. We aimed to examine a multicomponent integrated care (MIC) program on diabetes care goals and determine the effect of SDH and ODH on T2DM patients.
A before-and-after design (a pretest, a 5-month intervention, and a follow-up) was used in a T2DM population from Mexico City. The SDH included education level and socioeconomic status; the ODH included diabetes knowledge, self-care scores, and deltas (i.e., differences between baseline and follow-up scores). The triple-target goal (glycated hemoglobin, blood pressure, and LDL-cholesterol) was established as a measurement of T2DM goals.
The DIABEMPIC (DIABetes EMPowerment and Improvement of Care) intervention (n = 498) reduced the glycated hemoglobin levels (mean reduction 2.65%, standard deviation SD: 2.02%) and cardiometabolic parameters; it also improved health-related quality of life. From 1.81% at baseline, 25.9% of participants (p-value< 0.001) achieved the triple-target goal. We found a significant association between education level (p-value = 0.010), diabetes knowledge at baseline (p-value = 0.004), and self-care scores at baseline (p-value = 0.033) in the delta (change between baseline and follow-up assessments) of HbA1c levels. Improvements (increase) in diabetes knowledge (p-value = 0.006) and self-care scores (p-value = 0.002) were also associated with greater reductions in HbA1c.
MIC strategies in urban primary care settings contribute to control of T2DM. SDH, such as education level, and ODH (diabetes knowledge and self-care scores at baseline) play a key role in improving glycemic control in these settings.
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