Wetland-based passive treatment systems for gold ore processing effluents containing residual cyanide, metals and nitrogen species

Gold extraction operations generate a variety of wastes requiring responsible disposal in compliance with current environmental regulations. During recent decades, increased emphasis has been placed on effluent control and treatment, in order to avoid the threat to the environment posed by toxic constituents. In many modern gold mining and ore processing operations, cyanide species are of most immediate concern. Given that natural degradation processes are known to reduce the toxicity of cyanide over time, trials have been made at laboratory and field scales into the feasibility of using wetland-based passive systems as low-cost and environmentally friendly methods for long-term treatment of leachates from closed gold mine tailing disposal facilities. Laboratory experiments on discrete aerobic and anaerobic treatment units supported the development of design parameters for the construction of a field-scale passive system at a gold mine site in northern Spain. An in situ pilot-scale wetland treatment system was designed, constructed and monitored over a nine-month period. Overall, the results suggest that compost-based constructed wetlands are capable of detoxifying cyanidation effluents, removing about 21.6% of dissolved cyanide and 98% of Cu, as well as nitrite and nitrate. Wetland-based passive systems can therefore be considered as a viable technology for removal of residual concentrations of cyanide from leachates emanating from closed gold mine tailing disposal facilities

Estudio de los factores que determinan la respuesta de adaptación ácida y de protección cruzada frente al calor de Salmonella Typhimurium y Salmonella Senftenberg: mecanismos implicados = Factors influencing the acid tolerance and cross-protection responses of "Salmonella" Typhimurium and "Salmonella" Senftenberg: mechanisms involved

230 p.Este trabajo de investigación se ha centrado en determinar la respuesta frente al estrés ácido de dos serovariedades del género Salmonella, de gran interés sanitario y tecnológico, S. Typhimurium y S. Senftenberg, en presencia de diversos ácidos orgánicos de uso habitual en la industria alimentaria. Los resultados obtenidos han permitido demostrar que la adaptación de ambas serovariedades en ambientes ácidos moderados origina respuestas adaptativas de tolerancia ácida, que se manifiestan por un incremento de su subsecuente resistencia a condiciones ácidas letales, y de protección cruzada frente a tratamientos térmicos, tanto en medios de laboratorio como en zumos de naranja y manzana. Asimismo hemos comprobado que diversos parámetros ambientales, como la temperatura de crecimiento, la composición del medio de cultivo y tratamiento, o el tipo de ácido utilizado, condicionan la expresión y la magnitud de dichas respuestas adaptativa

Estimación de la Tasa de Descuento para la evaluación de Proyectos de Inversión Privados: Caso Ecuador

El presente artículo tiene como finalidad abordar los diferentes métodos o criterios que se utilizan para estimar la tasa mínima atractiva de retorno y a la vez identificar algunas dificultades que pueden surgir al momento de aplicar dichos métodos o criterios en la evaluación de un proyecto de inversión privado en el Ecuado

La intervención escolar en los trastornos del espectro autista

[Resumen] La integración social y escolar de los niños con trastorno del espectro autista es un hecho consumado desde los últimos años. Sin embargo, su práctica debe considerar una serie de adaptaciones y ajustes. Las limita- ciones que manifiestan estos niños son muy variadas y heterogéneas, lo que en la práctica escolar debe traducirse por una actuación educativa que de respuesta a sus necesidades y habilidades. El objetivo del presente artícu- lo es revisar algunas cuestiones centrales para la intervención psicoeducativa de los niños con trastorno de espectro autista, las modalidades de escolarización y las adapta- ciones tanto curriculares como sociales. Se proponen algunas mejoras para la puesta en marcha efectiva de las diferentes medidas educativas a adoptar.[Abstract] The social and school integration of chil- dren with autistic spectrum disorders is a fait accompli in recent years. However, its practi- ce must consider a series of adaptations and adjustments. These children show a variety of heterogeneous limitations, what in the school practice must be translated into an educative performance that responds to their needs and abilities. The goal of this article is to revise some vital questions for the psychoeducative intervention in children with autistic spectrum disorders, for the different schooling systems and for the curricular or social adaptations. Improvements are proposed in order to carry out an effective launch of the different educa- tive measures that must be taken

Enteral Nutrition by Nasogastric Tube in Adult Patients under Palliative Care: A Systematic Review

Nutritional management of patients under palliative care can lead to ethical issues, especially when Enteral Nutrition (EN) is prescribed by nasogastric tube (NGT). The aim of this review is to know the current status in the management of EN by NG tube in patients under palliative care, and its effect in their wellbeing and quality of life. The following databases were used: PubMed, Web of Science (WOS), Scopus, Scielo, Embase and Medline. After inclusion and exclusion criteria were applied, as well as different qualities screening, a total of three entries were used, published between 2015 and 2020. In total, 403 articles were identified initially, from which three were selected for this review. The use of NGT caused fewer diarrhea episodes and more restrictions than the group that did not use NG tubes. Furthermore, the use of tubes increased attendances to the emergency department, although there was no contrast between NGT and PEG devices. No statistical difference was found between use of tubes (NGT and PEG) or no use, with respect to the treatment of symptoms, level of comfort, and satisfaction at the end of life. Nevertheless, it improved hospital survival compared with other procedures, and differences were found in hospital stays in relation to the use of other probes or devices. Finally, there are not enough quality studies to provide evidence on improving the health status and quality of life of the use of EN through NGT in patients receiving palliative care. For this reason, decision making in this field must be carried out individually, weighing the benefits and damages that they can cause in the quality of life of the patients

Whole Resistome Analysis in Campylobacter jejuni and C. coli Genomes Available in Public Repositories

-Campylobacter spp. are the most frequent agent of human gastroenteritis worldwide, and the spread of multidrug-resistant strains makes the clinical treatment difficult. The current study presents the resistome analysis of 39,798 Campylobacter jejuni and 11,920 Campylobacter coli genomes available in public repositories. Determinants of resistance to β-lactams (Be) and tetracyclines (Te) were the most frequent for both species, with resistance to quinolones (Qu) as the third most important on C. jejuni and to aminoglycosides (Am) on C. coli. Moreover, resistance to Te, Qu, and Am was frequently found in co-occurrence with resistance to other antibiotic families. Geographical differences on clonal complexes distribution were found for C. jejuni and on resistome genotypes for both C. jejuni and C. coli species. Attending to the resistome patterns by isolation source, three main clusters of genomes were found on C. jejuni genomes at antimicrobial resistance gene level. The first cluster was formed by genomes from human, food production animals (e.g., sheep, cow, and chicken), and food (e.g., dairy products) isolates. The higher incidence of tet(O), associated with tetracycline resistance, and the gyrA (T86I) single-nucleotide polymorphism (SNP), associated with quinolone resistance, among genomes from this cluster could be due to the intense use of these antibiotics in veterinary and human clinical settings. Similarly, a high incidence of tet(O) genes of C. coli genomes from pig, cow, and turkey was found. Moreover, the cluster based on resistome patterns formed by C. jejuni and C. coli genomes of human, turkey, and chicken origin is in agreement with previous observations reporting chicken or poultry-related environments as the main source of human campylobacteriosis infections. Most clonal complexes (CCs) associated with chicken host specialization (e.g., ST-354, ST-573, ST-464, and ST-446) were the CCs with the highest prevalence of determinants of resistance to Be, Qu, and Te. Finally, a clear trend toward an increase in the occurrence of Te and Qu resistance determinants on C. jejuni, linked to the spread of the co-occurrence of the bla OXA−61 and tet(O)-tet(O/W/O) genes and the gyrA (T86I) SNP, was found from 2001 to date in Europe.S

Application of lactic acid bacteria for the biopreservation of meat products: A systematic review

Systematic ReviewThe increasing concern of consumers about food quality and safety and their rejection of chemical additives has promoted the breakthrough of the biopreservation field and the development of studies on the use of beneficial bacteria and their metabolites as potential natural antimicrobials for shelf life extension and enhanced food safety. Control of foodborne pathogens in meat and meat products represents a serious challenge for the food industry which can be addressed through the intelligent use of bio-compounds or biopreservatives. This article aims to systematically review the available knowledge about biological strategies based on the use of lactic acid bacteria to control the proliferation of undesirable microorganisms in different meat products. The outcome of the literature search evidenced the potential of several strains of lactic acid bacteria and their purified or semi- purified antimicrobial metabolites as biopreservatives in meat products for achieving longer shelf life or inhibiting spoilage and pathogenic bacteria, especially when combined with other technologies to achieve a synergistic effect.S

Corticoides : 60 años después, una asignatura pendiente

El objetivo de este artículo es hacer una breve recopilación de la fisiología del eje hipotálamo-hipofisiario-suprarrenal, para comprender el papel de los corticoides exógenos como herramientas terapéuticas en innumerables patologías, que, utilizados de manera inapropiada, pueden causar efectos deletéreos importantes. La historia de los corticoides empezó hace 164 años, en 1843, cuando Thomas Addison describió los síntomas de la insuficiencia suprarrenal. Casi 100 años después, el 21 de septiembre de 1948, marcó un hito en la historia de la medicina, cuando, en la Clínica Mayo, el Dr. Hench inyectó 100 g de cortisona por primera vez en un paciente con artritis reumatoidea. En 1950, Hench, Kendall y Reichstein recibieron el Premio Nobel de Medicina y Fisiología. En la corteza de las glándulas suprarrenales se sintetizan, a partir del colesterol, tres hormonas diferentes con diversos efectos sobre la homeostasis. Los glucocorticoides sintéticos se clasifican por su potencia antiinflamatoria, vida media y efecto mineralocorticoide; operan en casi todas las células por medio de mecanismos de acción genómicos y no genómicos, lo que genera diferentes respuestas, de ahí su amplio efecto terapéutico en esclerosis múltiple, rechazo de trasplantes, enfermedades respiratorias, como asma y Epoc, entre otras.The objective of this article is to make a brief compilation of the physiology of the hypothalamic-pituitary-adrenal axis in order to understand the role of the exogenous corticoids as therapeutic tools in innumerable pathologies, but when used inappropriately, it can produce important deleterious effects. The history of the corticoids began 164 years ago in 1843 when Thomas Addison described the symptoms of the adrenal gland insufficiency. On September 21st 1948, almost one hundred years after, Dr. Hench injected cortisone for the first time in a patient with arthritis. In 1950 Hench, Kendall and Reichstein received the Nobel Prize in Medicine and Physiology. In the cortex of the adrenal glands, three different hormones are synthesized from cholesterol, and these hormones produce diverse effects on the homeostasis of the body. The synthetic glucocorticoids are classified by their anti-inflammatory power, half life, and mineralocorticoid effect; they operate in almost every cell through genomic and non genomic mechanisms of action producing different responses. This is the reason of their wide therapeutic effect in respiratory diseases like asthma and COPD, multiple sclerosis, rejection of transplants, among others

Application of lactic acid bacteria for the biopreservation of meat products: A systematic review

.The increasing concern of consumers about food quality and safety and their rejection of chemical additives has promoted the breakthrough of the biopreservation field and the development of studies on the use of beneficial bacteria and their metabolites as potential natural antimicrobials for shelf life extension and enhanced food safety. Control of foodborne pathogens in meat and meat products represents a serious challenge for the food industry which can be addressed through the intelligent use of bio-compounds or biopreservatives. This article aims to systematically review the available knowledge about biological strategies based on the use of lactic acid bacteria to control the proliferation of undesirable microorganisms in different meat products. The outcome of the literature search evidenced the potential of several strains of lactic acid bacteria and their purified or semi-purified antimicrobial metabolites as biopreservatives in meat products for achieving longer shelf life or inhibiting spoilage and pathogenic bacteria, especially when combined with other technologies to achieve a synergistic effect.S