23 research outputs found
Coliform and Metal Contamination in Lago de Colina, a Recreational Water Body in Chihuahua State, Mexico
Lago de Colina (Colina Lake) is located about 180 km south of the city of Chihuahua (Mexico), and during the Semana Santa (Holy Week) vacation period its recreational use is high. The objective of this study was to quantify coliform and heavy metal levels in this water body before and after the Holy Week vacation period in 2010. Twenty sampling points were randomly selected and two water samples were collected at each point near the surface (0.30 m) and at 1 m depth. After the Holy Week vacation the same twenty points were sampled at the same depths. Therefore, a total 80 water samples were analyzed for fecal and total coliforms and levels of the following metals: Al, As, B, Ca, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Se, Si and Zn. It was hypothesized that domestic tourism contaminated this water body, and as a consequence, could have a negative impact on visitor health. An analysis of variance (ANOVA) study was performed for each element and its interactions considering a factorial design where factor A was sample date and factor B was sample depth. Fecal coliforms were only detected at eight sampling points in the first week, but after Holy Week, both fecal and total coliforms were detected at most sampling points. The concentrations of Al, B, Na, Ni and Se were only statistically different for factor A. The levels of Cr, Cu, K and Mg was different for both date and depth, but the dual factor interaction was not significant. The amount of Ca and Zn was statistically different due to date, depth and their interaction. No significant differences were found for any factor or the interaction for the elements As, Fe and Mn. Because of the consistent results, it is concluded that local tourism is contaminating the recreational area of Colina Lake, Chihuahua, Mexico
El papel de los antimicrobianos en la estructura de las comunidades microbianas en la naturaleza
Los microambientes son estructuras complejas, en donde se encuentran en equilibrio una gran cantidad de organismos microscópicos, tanto eucariotes como procariotes, que interaccionan entre ellos y con los factores abióticos del medio. Para lograr el equilibrio entre los miembros de una comunidad microbiana, se establecen interacciones que resultan benéficas o perjudiciales para una de las especies que interaccionan, o para ambas. Entre estas interacciones, se encuentran: comensalismo, simbiosis, y parasitismo, entre otras. Estas interacciones les facilita a los microorganismos la obtención de compuestos que pueden ser utilizados como substratos o como complementos, asegurando así su sobrevivencia y mantenimiento en un ecosistema. Para sobrevivir, algunos microorganismos deben producir compuestos capaces de inhibir el desarrollo de microorganismos competidores. Estos compuestos, conocidos como antimicrobianos, pueden causar daño a la célula bacteriana competidora a través de diversos mecanismos de acción, pero el fin es cumplir con el mismo objetivo, la eliminación de la competencia microbiana. La producción industrial de algunos de estos antimicrobianos, han revolucionado nuestra forma de vida, al proporcionarnos herramientas para el control de enfermedades infecciosas.
Abstract
Microenvironments are natural complex structures, where microscopic organisms (both, eukaryotic and prokaryotic organisms) are in balance, by way of interactions among them and with the abiotic factors present in the environment. In order to achieve equilibrium between the members of a microbial community, different interactions are established, that are either beneficial or prejudicial to one or both interaction species. Among those interactions are commensalism, symbiosis and parasitism. The interactions support the acquirement of compounds that can be used as substrates or complements for microbial growth, assuring in this way, its survival and maintenance in the ecosystem. To survive, some microorganisms produce compounds capable of inhibiting the development of competitive microbiota. Those compounds, known as antimicrobials, can cause damage to the competitive microbial cell through different mechanisms of action, but the final goal is the same: to eliminate the competitive microbiota. Industrial production of some of those antimicrobials, have revolutionized our society, since they can be used to control infectious diseases.
Keywords: microbial interactions, symbiosis, parasitism, competition, bacteria
Plant growth environments with programmable relative humidity and homogeneous nutrient availability
We describe the design, characterization, and use of “programmable”, sterile growth environments for individual (or small sets of) plants. The specific relative humidities and nutrient availability experienced by the plant is established (RH between 15% and 95%; nutrient concentration as desired) during the setup of the growth environment, which takes about 5 minutes and <1$ in disposable cost. These systems maintain these environmental parameters constant for at least 14 days with minimal intervention (one minute every two days). The design is composed entirely of off-the-shelf components (e.g., LEGO® bricks) and is characterized by (i) a separation of root and shoot environment (which is physiologically relevant and facilitates imposing specific conditions on the root system, e.g., darkness), (ii) the development of the root system on a flat surface, where the root enjoys constant contact with nutrient solution and air, (iii) a compatibility with root phenotyping.
We demonstrate phenotyping by characterizing root systems of Brassica rapa plants growing in different relative humidities (55%, 75%, and 95%). While most phenotypes were found to be sensitive to these environmental changes, a phenotype tightly associated with root system topology – the size distribution of the areas encircled by roots – appeared to be remarkably and counterintuitively insensitive to humidity changes.
These setups combine many of the advantages of hydroponics conditions (e.g., root phenotyping, complete control over nutrient composition, scalability) and soil conditions (e.g., aeration of roots, shading of roots), while being comparable in cost and setup time to Magenta® boxes
Impact of Arterial Stiffness on All-Cause Mortality in Patients Hospitalized With COVID-19 in Spain
Older age and cardiovascular comorbidities are well-known risk factors for all-cause mortality in patients with coronavirus disease 2019 (COVID-19). Hypertension and age are the 2 principal determinants of arterial stiffness (AS). This study aimed to estimate AS in patients with COVID-19 requiring hospitalization and analyze its association with all-cause in-hospital mortality. This observational, retrospective, multicenter cohort study analyzed 12 170 patients admitted to 150 Spanish centers included in the SEMI-COVID-19 Network. We compared AS, defined as pulse pressure ≥60 mm Hg, and clinical characteristics between survivors and nonsurvivors. Mean age was 67.5 (±16.1) years and 42.5% were women. Overall, 2606 (21.4%) subjects died. Admission systolic blood pressure (BP) <120 and ≥140 mm Hg was a predictor of higher all-cause mortality (23.5% and 22.8%, respectively, P<0.001), compared with systolic BP between 120 and 140 mm Hg (18.6%). The 4379 patients with AS (36.0%) were older and had higher systolic and lower diastolic BP. Multivariate analysis showed that AS and systolic BP <120 mm Hg significantly and independently predicted all-cause in-hospital mortality (adjusted odds ratio [ORadj]: 1.27, P=0.0001; ORadj: 1.48, P=0.0001, respectively) after adjusting for sex (males, ORadj: 1.6, P=0.0001), age tertiles (second and third tertiles, ORadj: 2.0 and 4.7, P=0.0001), Charlson Comorbidity Index (second and third tertiles, ORadj: 4.8 and 8.6, P=0.0001), heart failure, and previous and in-hospital antihypertensive treatment. Our data show that AS and admission systolic BP <120 mm Hg had independent prognostic value for all-cause mortality in patients with COVID-19 requiring hospitalization
Differences in clinical features and mortality in very old unvaccinated patients (≥ 80 years) hospitalized with COVID-19 during the first and successive waves from the multicenter SEMI-COVID-19 Registry (Spain)
Background: Old age is one of the most important risk factors for severe COVID-19. Few studies have analyzed changes in the clinical characteristics and prognosis of COVID-19 among older adults before the availability of vaccines. This work analyzes differences in clinical features and mortality in unvaccinated very old adults during the first and successive COVID-19 waves in Spain. Methods This nationwide, multicenter, retrospective cohort study analyzes unvaccinated patients >= 80 years hospitalized for COVID-19 in 150 Spanish hospitals (SEMI-COVID-19 Registry). Patients were classified according to whether they were admitted in the first wave (March 1-June 30, 2020) or successive waves (July 1-December 31, 2020). The endpoint was all-cause in-hospital mortality, expressed as the case fatality rate (CFR). Results Of the 21,461 patients hospitalized with COVID-19, 5,953 (27.7%) were >= 80 years (mean age [IQR]: 85.6 [82.3-89.2] years). Of them, 4,545 (76.3%) were admitted during the first wave and 1,408 (23.7%) during successive waves. Patients hospitalized in successive waves were older, had a greater Charlson Comorbidity Index and dependency, less cough and fever, and met fewer severity criteria at admission (qSOFA index, PO2/FiO2 ratio, inflammatory parameters). Significant differences were observed in treatments used in the first (greater use of antimalarials, lopinavir, and macrolides) and successive waves (greater use of corticosteroids, tocilizumab and remdesivir). In-hospital complications, especially acute respiratory distress syndrome and pneumonia, were less frequent in patients hospitalized in successive waves, except for heart failure. The CFR was significantly higher in the first wave (44.1% vs. 33.3%; -10.8%; p = 95 years (54.4% vs. 38.5%; -15.9%; p < 0.001). After adjustments to the model, the probability of death was 33% lower in successive waves (OR: 0.67; 95% CI: 0.57-0.79). Conclusions Mortality declined significantly between the first and successive waves in very old unvaccinated patients hospitalized with COVID-19 in Spain. This decline could be explained by a greater availability of hospital resources and more effective treatments as the pandemic progressed, although other factors such as changes in SARS-CoV-2 virulence cannot be ruled out
Spatiotemporal Characteristics of the Largest HIV-1 CRF02_AG Outbreak in Spain: Evidence for Onward Transmissions
Background and Aim: The circulating recombinant form 02_AG (CRF02_AG) is the predominant clade among the human immunodeficiency virus type-1 (HIV-1) non-Bs with a prevalence of 5.97% (95% Confidence Interval-CI: 5.41–6.57%) across Spain. Our aim was to estimate the levels of regional clustering for CRF02_AG and the spatiotemporal characteristics of the largest CRF02_AG subepidemic in Spain.Methods: We studied 396 CRF02_AG sequences obtained from HIV-1 diagnosed patients during 2000–2014 from 10 autonomous communities of Spain. Phylogenetic analysis was performed on the 391 CRF02_AG sequences along with all globally sampled CRF02_AG sequences (N = 3,302) as references. Phylodynamic and phylogeographic analysis was performed to the largest CRF02_AG monophyletic cluster by a Bayesian method in BEAST v1.8.0 and by reconstructing ancestral states using the criterion of parsimony in Mesquite v3.4, respectively.Results: The HIV-1 CRF02_AG prevalence differed across Spanish autonomous communities we sampled from (p < 0.001). Phylogenetic analysis revealed that 52.7% of the CRF02_AG sequences formed 56 monophyletic clusters, with a range of 2–79 sequences. The CRF02_AG regional dispersal differed across Spain (p = 0.003), as suggested by monophyletic clustering. For the largest monophyletic cluster (subepidemic) (N = 79), 49.4% of the clustered sequences originated from Madrid, while most sequences (51.9%) had been obtained from men having sex with men (MSM). Molecular clock analysis suggested that the origin (tMRCA) of the CRF02_AG subepidemic was in 2002 (median estimate; 95% Highest Posterior Density-HPD interval: 1999–2004). Additionally, we found significant clustering within the CRF02_AG subepidemic according to the ethnic origin.Conclusion: CRF02_AG has been introduced as a result of multiple introductions in Spain, following regional dispersal in several cases. We showed that CRF02_AG transmissions were mostly due to regional dispersal in Spain. The hot-spot for the largest CRF02_AG regional subepidemic in Spain was in Madrid associated with MSM transmission risk group. The existence of subepidemics suggest that several spillovers occurred from Madrid to other areas. CRF02_AG sequences from Hispanics were clustered in a separate subclade suggesting no linkage between the local and Hispanic subepidemics
Microbiological Impact of the Use of Reclaimed Wastewater in Recreational Parks
Reclaimed wastewater for irrigation is an opportunity for recovery of this natural resource. In this study, microbial risk from the use of treated wastewater for irrigation of recreational parks in the city of Chihuahua, evaluating the effect of distribution distance, season, and presence of storage tanks, was analyzed. Escherichia coli, Salmonella, and multidrug-resistant bacteria were recovered from samples of reclaimed water and soils at recreational parks in Chihuahua by the membrane filtration method, using selected agars for microbial growth. Samples were taken at three different seasons. No correlation in the presence of microbial indicators and multidrug-resistant bacteria (p > 0.05) was found between the distance from the wastewater treatment plant to the point of use. Presence of storage tanks in parks showed a significant effect (p < 0.05) with a higher level of E. coli. The highest count in wastewater occurred in summer. We isolated 392 multidrug-resistant bacteria from water and soil; cluster analysis showed that the microorganisms at each location were of different origins. Irrigation with reclaimed wastewater did not have a negative effect on the presence of microbial indicators of the quality of soils in the parks. However, the prevalence of multidrug-resistant bacteria still represents a potential risk factor for human health
“Los Grandes" a digital platform that is the link between the user and elderly adults who offer general services in Metropolitan Lima
La pandemia por la Covid-19 mostró realidades diferentes. Por un lado, los más vulnerables, personas adultas mayores y, por el otro, la gran mayoría de la población económicamente activa joven que permaneció en casa por las cuarentenas. El mundo como lo conocimos cambió y con él, las necesidades se hicieron más notorias, pero surgieron nuevas oportunidades de negocio, de comunicación, entre otras.
Así nació “Los Grandes” con la finalidad de cubrir dos necesidades: por un lado, nuestros clientes que buscan soluciones rápidas y confiables para reparar o dar mantenimiento a algún servicio dentro de su hogar y por el otro, personas adultas mayores que buscan una oportunidad laboral para generar ingresos económicos propios.
Este proyecto tiene por objetivo crear una plataforma digital que exponga el trabajo de las personas adultas mayores, quienes son nuestros expertos, en los diversos servicios generales y así ponerlos en contacto con miles de personas, nuestros clientes, que buscan sus servicios.
La idea fue validada con el análisis del entorno y estudio de investigación, donde se realizaron focus group, entrevistas y encuestas para conocer a los clientes potenciales. Además, se empleó el Customer Centricity, donde pusimos al cliente, al centro del desarrollo de la solución.
Concluimos que existe la necesidad y oportunidad del desarrollo de la idea de negocio que brindará un servicio basado en la experiencia y haciendo énfasis en el insight de la confianza. El estudio demuestra que es un proyecto rentable, con responsabilidad social y proyección de negocio sostenible.The pandemic of covid-19 showed us different realities. On one side, the more vulnerable, elderly adults, and on the other side, the vast majority of the young economically active population that stayed at home due to quarantines. The world as we knew it changed with it, needs became more evident, but new business and communication opportunities arose, among others.
This is how "Los Grandes" (“The Big Ones”) was born with the purpose of covering two needs: on the one hand, our clients who are looking for quick and reliable solutions to repair or maintain a certain service in their homes, and on the other hand, elderly adults who are looking for a job opportunity to generate their own economic income.
This project aims to develop a digital platform that showcases the work of the elderly people, who are our experts, in the various general services and thus put them in contact with thousands of people, our clients, who are looking for their services.
The idea was validated with the analysis of the environment and research study, where focus groups, interviews, and surveys were conducted to meet potential customers. In addition, Customer Centricity was used, where we placed the customer at the center of the development of the solution.
We conclude that there is a necessity and opportunity for the development of the business idea that will provide a service based on experience and emphasize the insight of trust. The study shows that it is a profitable project, with social responsibility and sustainable business projection.Trabajo de investigació