Expanded granular sludge bed bioreactor in wastewater treatment

The expanded granular sludge bed bioreactor appears today as a cheap, robust and more popular technology because it operates using a fluidized bed, which allows increasing in organic load and in cell retention times, generating higher treatment efficiencies (up to 95 %) and renewable energy (i.e., biogas, biomethane, and biohydrogen). Nevertheless, the efficiency of this bioreactor mainly depends on the operating conditions. Thus, the content presented in this review paper focuses on the analysis of the operating conditions and performance of expanded granular sludge bed bioreactor for treating different types of industrial, agro-industrial and domestic wastewaters (e.g., agro-food, beverage, alcohol distillery, tannery, slaughterhouse, chemical, pharmaceutical, municipal sewage, among others). Because of this reason, this study aimed to analyze the operating conditions and type of substrate, which has been used in these bioreactors to improve future research to wastewater treatment and renewable energy production. According to the review, it is concluded that the EGSB bioreactor is a novel sustainable alternative to treat different types of wastewaters and consequently change the paradigm of wastewater management from "treatment and disposal" to "beneficial use" as well as "profitable effort"

A canine leishmaniasis pilot survey in an emerging focus of visceral leishmaniasis: Posadas (Misiones, Argentina)

<p>Abstract</p> <p>Background</p> <p>An increasing number of reports are calling our attention to the worldwide spread of leishmaniasis. The urbanization of zoonotic visceral leishmaniasis (VL) has been observed in different South American countries, due to changes in demographic and ecological factors. In May 2006, VL was detected for the first time in the city of Posadas (Misiones, Argentina). This event encouraged us to conduct a clinical and parasitological pilot survey on domestic dogs from Posadas to identify their potential role as reservoirs for the disease.</p> <p>Methods</p> <p>One hundred and ten dogs from the city of Posadas were included in the study. They were selected based on convenience and availability. All dogs underwent clinical examination. Symptomatology related to canine leishmaniasis was recorded, and peripheral blood and lymph node aspirates were collected. Anti-<it>Leishmania </it>antibodies were detected using rK39-immunocromatographic tests and IFAT. Parasite detection was based on peripheral blood and lymph node aspirate PCR targeting the <it>SSUrRNA </it>gene. Molecular typing was addressed by DNA sequence analysis of the PCR products obtained by <it>SSUrRNA </it>and ITS-1 PCR.</p> <p>Results</p> <p>According to clinical examination, 69.1% (76/110) of the dogs presented symptoms compatible with canine leishmaniasis. Serological analyses were positive for 43.6% (48/110) of the dogs and parasite DNA was detected in 47.3% (52/110). A total of 63 dogs (57.3%) were positive by serology and/or PCR. Molecular typing identified <it>Leishmania infantum </it>(syn. <it>Leishmania chagasi</it>) as the causative agent.</p> <p>Conclusions</p> <p>This work confirms recent findings which revealed the presence of <it>Lutzomyia longipalpis</it>, the vector of <it>L. infantum </it>in this area of South America. This new VL focus could be well established, and further work is needed to ascertain its magnitude and to prevent further human VL cases.</p

Variants in toll-like receptor 9 gene influence susceptibility to tuberculosis in a Mexican population

Background: The control of Mycobacterium tuberculosis (Mtb) infection begins with the recognition of mycobacterial structural components by toll like receptors (TLRs) and other pattern recognition receptors. Our objective was to determine the influence of TLRs polymorphisms in the susceptibility to develop tuberculosis (TB) in Amerindian individuals from a rural area of Oaxaca, Mexico with high TB incidence. Methods: We carried out a case–control association community based study, genotyping 12 polymorphisms of TLR2, TLR4, TLR6 and TLR9 genes in 90 patients with confirmed pulmonary TB and 90 unrelated exposed but asymptomatic household contacts. Results: We found a significant increase in the frequency of the allele A of the TLR9 gene polymorphism rs352139 (A>G) in the group of TB patients (g.f. = 0.522) when compared with controls (g.f. = 0.383), (Pcorr = 0.01, OR = 1.75). Under the recessive model (A/G + A/A vs G/G) this polymorphism was also significantly associated with TB (Pcorr = 0.01, OR= 2.37). The association of the SNP rs352139 was statistically significant after adjustment by age, gender and comorbidities by regression logistic analysis (Dominant model: p value = 0.016, OR = 2.31; Additive model: p value = 0.023, OR = 1.68). The haplotype GAA of TLR9 SNPs was also associated with TB susceptibility (Pcorr = 0.02). Differences in the genotype or allele frequencies of TLR2, TLR4 and TLR6 polymorphisms between TB patients and healthy contacts were not detected. Conclusions: Our study suggests that the allele A of the intronic polymorphism rs352139 on TLR9 gene might contribute to the risk of developing TB in Mexican Amerindians

La atención prenatal en la ciudad fronteriza de Tijuana, México

El presente estudio se diseñó con el fin de conocer las condiciones en las que se realiza el control prenatal en la ciudad fronteriza de Tijuana, Baja California, México y de estudiar las posibles asociaciones entre ese tipo de atención y el resultado neonatal en términos de peso al nacer, estado de salud del neonato y prematuridad. Se seleccionaron siete hospitales que atienden a personas de diferentes estratos socioeconómicos y entre diciembre de 1993 y marzo de 1994 se entrevistó en ellos a 279 mujeres que cursaban las primeras 24 a 48 horas del puerperio. En la entrevista se recogieron datos sobre nivel socioeconómico; conceptos, actitudes y prácticas de las madres respecto de la salud obstétrica; percepción materna de acceso a los servicios de atención prenatal; calidad de las consultas de control prenatal (evaluada según la realización de pruebas de sangre y orina y la medición de la tensión arterial y del peso); y antecedentes ginecobstétricos y de salud de la madre. Se elaboró una base de datos con el paquete estadístico SPSS y se exploraron posibles asociaciones entre la atención prenatal como variable independiente y las diferentes variables dependientes mediante tablas de contingencia y la prueba de Fisher de dos colas

Capacitación en la Investigación. Realidad y desafíos en la UNAH

La Dirección de Investigación Científica de la UNAH fortalece la capacitación en la investigación, tanto a docentes como a estudiantes de postgrado