49 research outputs found
Niveles de monóxido de carbono en el aire urbano de San Miguel de Tucumán, Argentina
Carbon monoxide, a highly toxic gas, is one of the most common and widely distributed air pollutants; in San Miguel de Tucumán, Argentina, the main sources of emission are the vehicle engines and the fire produced by the burning of cane fields. The objective was to evaluate the local levels of carbon monoxide (CO) concentration in the urban air of San Miguel de Tucumán during a period of 13 years. Four monitoring stations with high population concentration were selected. Testo 625 measuring instruments with specific probe for CO were used. The measure-ments were made during the months of September, October and November during the period 2003-2015. The concentrations of CO were compared using Variance analysis of Kruskal & Wal-lis and Conover post-test at 5 % significance. Minimum, maximum and Percentiles values (P25, P50 and P75) were considered. Results: No significant differences were observed in annual CO concentrations (p = 0.7177), with min = 24ppm, P25 = 28 ppm, P50 =28.9 ppm, P75 = 32 ppm and maximum = 38 ppm. With significant differences in CO concentrations (p <0.001) according to month and sampling season, higher values were detected in the month of November in Station 4 with min=27.0ppm, P25=30.7 ppm, P50=31.0 ppm, P75=33.2 ppm and maximum=38.0 ppm. Conclusion: The City of San Miguel de Tucumán is located in a mountainous area with little air movement, which means it has a notable accumulation of atmospheric pollutants, with high concentrations of CO in the microcenter of this city.El monóxido de carbono (CO), gas altamente tóxico, es uno de los contaminantes atmosféricos más comunes y ampliamente distribuidos. En San Miguel de Tucumán, Argentina, las principa-les fuentes de emisión son los motores de vehículos y los incendios producidos por la quema de cañaverales. El objetivo de la presente investigación fue evaluar los niveles locales de concen-tración de CO en el aire urbano de San Miguel de Tucumán durante un período de trece años. Se seleccionaron cuatro estaciones de monitoreo con alta concentración poblacional. Se emplearon instrumentos de medición Testo 625, con sonda específica para CO. Las mediciones se realizaron en los meses de septiembre, octubre y noviembre durante el período 2003-2015. Las concen-traciones de CO se compararon empleando análisis de la varianza de Kruskal-Wallis y postest de Conover al 5 % de significación. Se consideraron valores mínimos, máximos y percentiles P25, P50 y P75. Resultados: No se observaron diferencias significativas en las concentraciones anuales de CO (p = 0,7177), con min = 24 ppm, P25 = 28 ppm, P50 = 28,9 ppm, P75 = 32 ppm y máximo = 38 ppm. Con diferencias significativas en las concentraciones de CO (p < 0,001), se-gún mes y estación de muestreo. Los mayores valores fueron detectados en el mes de noviembre en Estación 4, con min = 27,0 ppm, P25 = 30,7 ppm, P50 = 31,0 ppm, P75 = 33,2 ppm y máximo = 38,0 ppm. La ciudad de San Miguel de Tucumán se encuentra en zona montañosa, con escaso movimiento de aire, lo que determina una marcada acumulación de contaminantes atmosféricos, con concentraciones de CO elevadas en el microcentro de esta ciudad.Biotecnologí
The role of two families of bacterial enzymes in putrescine synthesis from agmatine via agmatine deiminase
Putrescine, one of the main biogenic amines associated to microbial food spoilage, can be formed by bacteriafrom arginine via ornithine decarboxylase (ODC), or from agmatine via agmatine deiminase (AgDI). This study aims to correlate putrescine production from agmatine to the pathway involving N-carbamoylputrescine formation via AdDI (the aguAproduct) and N-carbamoylputrescine amidohydrolase (the aguB product), or putrescine carbamoyltransferase (the ptcA product) in bacteria. PCR methods were developed to detect the two genes involved in putrescine production from agmatine.Putrescine production from agmatine could be linked to the aguA and ptcA genes in Lactobacillus hilgardii X1B,Enterococcus faecalis ATCC 11700, and Bacillus cereus ATCC 14579. By contrast Lactobacillus sakei 23K was unable toproduce putrescine, and although a fragment of DNA corresponding to the gene aguA was amplified, no amplification wasobserved for the ptcA gene. Pseudomonasaeruginosa PAO1 produces putrescine and is reported to harbour aguA and aguBgenes, responsible for agmatine deiminase and N-carbamoylputrescine amidohydrolase activities. The enzyme from P. aeruginosa PAO1 that converts N-carbamoylputrescine to putrescine (the aguB product) is different from other microorganismsstudied (the ptcA product). Therefore, the aguB gene from P. aeruginosa PAO1 could not be amplified with ptcA specificprimers. The aguB and ptcA genes have frequently been erroneously annotated in the past, as in fact these two enzymes areneither homologous nor analogous. Furthermore, the aguA, aguB and ptcA sequences available from GenBank were subjected to phylogenetic analysis, revealing that gram-positive bacteria harboured ptcA, whereas gram-negative bacteria harbouraguB. This paper also discusses the role of the agmatine deiminase system (AgDS) in acid stress resistance. 
Insecticidal activities of diketopiperazines of Nomuraea rileyi entomopathogenic fungus
Entomopathogenic fungi are fungal organisms extensively used in various parts of the world as biopesticides against insect pests that cause important economic damage. Various secondary metabolites produced by these fungi have many potential biological activities. The present study was undertaken to evaluate the insecticidal activity of extracts and pure compounds from Nomuraea rileyi (Farlow) Samson entomopathogenic fungi against Spodoptera frugiperda Smith (Lepidoptera), Ceratitis capitata Wiedemann (Diptera) and Tribolium castaneum Herbst (Coleoptera), three insect pests that generate serious economic losses in the northwest of Argentina. Diketopiperazines were extracted from the culture free supernatant of the media with ethyl acetate. Antifeedant properties were detected in all extracts under dietary choice conditions (300 ug/ g of diet). The maximum antifeedant activity was noted in cycles (Pro-Val) (86.02) and cycle (Pro-Phe) (73.47), while the rest of the extracts and metabolites exhibited varying degrees of moderate or less toxic effects. The maximum oviposition deterrence against C. capitata (55.86%) was recorded with cycle (Pro-Phe) at a 50 µm/cm2 dose. Culture medium extracts supplemented with insect remains and all pure compounds showed repellent action against T. castaneum. The main repellency was observed in phenylacetic acid and cycle (Pro-Val) with RI values of 42 and 41% respectively. The present study would suggest the possible utilization of entomopathogenic fungal metabolites as an effective agent for controlling insect pests that cause important economic losses
Puesta en marcha y operación de un sistema combinado de tratamiento de líquidos cloacales con reactores UASB y lagunas de estabilización
Se presenta la puesta en marcha y operación de una planta piloto para el tratamiento de líquidos cloacales, consistente en dos reactores UASB (reactores anaeróbicos de flujo ascendente y manto de lodos) seguidos de cinco lagunas de estabilización (LDE) en serie. La puesta en marcha del sistema fue realizada en aproximadamente un mes. La eficiencia de remoción de Demanda Química de Oxígeno (DQO) en las etapas anaeróbicas alcanzó el 90%, con Tiempos de Retención Hidráulica (TRH) de 6 + 6 h, mientras que la eficiencia de remoción de Sólidos Suspendidos Totales y Volátiles fue 98,1 y 99,1%, respectivamente. La remoción de Coliformes Fecales (CF) en el sistema completo fue 99.9999%, con 15 d de TRH en las LDE. La remoción total de huevos de helmintos fue 99.3%. El sistema estudiado es una opción atractiva para el tratamiento de líquidos cloacales en regiones subtropicales.In this work, the start-up and operation of a pilot-scale sewage treatment plant are described. The plant consists of two UASB (upflow anaerobic sludge blanket) reactors in series followed by five waste stabilization ponds (WSP), also in series. The start-up was accomplished in approximately one month. Chemical oxygen demand (COD) removal efficiency in the anaerobic steps reached 90%, with hydraulic retention times (HRT) of 6 + 6 h, while total and volatile suspended solids (TSS/VSS) removal was 98,1 and 99,1%, respectively. Faecal Coliforms (FC) removal in the entire system was 99.9999%, with 15 d HRT in the WSP. Total removal of helminth eggs was 99.3%. The studied system is an attractive option for sewage treatment in subtropical regions.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES
A chemical survey of exoplanets with ARIEL
Thousands of exoplanets have now been discovered with a huge range of masses, sizes and orbits: from rocky Earth-like planets to large gas giants grazing the surface of their host star. However, the essential nature of these exoplanets remains largely mysterious: there is no known, discernible pattern linking the presence, size, or orbital parameters of a planet to the nature of its parent star. We have little idea whether the chemistry of a planet is linked to its formation environment, or whether the type of host star drives the physics and chemistry of the planet’s birth, and evolution. ARIEL was conceived to observe a large number (~1000) of transiting planets for statistical understanding, including gas giants, Neptunes, super-Earths and Earth-size planets around a range of host star types using transit spectroscopy in the 1.25–7.8 μm spectral range and multiple narrow-band photometry in the optical. ARIEL will focus on warm and hot planets to take advantage of their well-mixed atmospheres which should show minimal condensation and sequestration of high-Z materials compared to their colder Solar System siblings. Said warm and hot atmospheres are expected to be more representative of the planetary bulk composition. Observations of these warm/hot exoplanets, and in particular of their elemental composition (especially C, O, N, S, Si), will allow the understanding of the early stages of planetary and atmospheric formation during the nebular phase and the following few million years. ARIEL will thus provide a representative picture of the chemical nature of the exoplanets and relate this directly to the type and chemical environment of the host star. ARIEL is designed as a dedicated survey mission for combined-light spectroscopy, capable of observing a large and well-defined planet sample within its 4-year mission lifetime. Transit, eclipse and phase-curve spectroscopy methods, whereby the signal from the star and planet are differentiated using knowledge of the planetary ephemerides, allow us to measure atmospheric signals from the planet at levels of 10–100 part per million (ppm) relative to the star and, given the bright nature of targets, also allows more sophisticated techniques, such as eclipse mapping, to give a deeper insight into the nature of the atmosphere. These types of observations require a stable payload and satellite platform with broad, instantaneous wavelength coverage to detect many molecular species, probe the thermal structure, identify clouds and monitor the stellar activity. The wavelength range proposed covers all the expected major atmospheric gases from e.g. H2O, CO2, CH4 NH3, HCN, H2S through to the more exotic metallic compounds, such as TiO, VO, and condensed species. Simulations of ARIEL performance in conducting exoplanet surveys have been performed – using conservative estimates of mission performance and a full model of all significant noise sources in the measurement – using a list of potential ARIEL targets that incorporates the latest available exoplanet statistics. The conclusion at the end of the Phase A study, is that ARIEL – in line with the stated mission objectives – will be able to observe about 1000 exoplanets depending on the details of the adopted survey strategy, thus confirming the feasibility of the main science objectives.Peer reviewedFinal Published versio
Disease-Modifying Therapies and Coronavirus Disease 2019 Severity in Multiple Sclerosis
Objective: This study was undertaken to assess the impact of immunosuppressive and immunomodulatory therapies on the severity of coronavirus disease 2019 (COVID-19) in people with multiple sclerosis (PwMS).
Methods: We retrospectively collected data of PwMS with suspected or confirmed COVID-19. All the patients had complete follow-up to death or recovery. Severe COVID-19 was defined by a 3-level variable: mild disease not requiring hospitalization versus pneumonia or hospitalization versus intensive care unit (ICU) admission or death. We evaluated baseline characteristics and MS therapies associated with severe COVID-19 by multivariate and propensity score (PS)-weighted ordinal logistic models. Sensitivity analyses were run to confirm the results.
Results: Of 844 PwMS with suspected (n = 565) or confirmed (n = 279) COVID-19, 13 (1.54%) died; 11 of them were in a progressive MS phase, and 8 were without any therapy. Thirty-eight (4.5%) were admitted to an ICU; 99 (11.7%) had radiologically documented pneumonia; 96 (11.4%) were hospitalized. After adjusting for region, age, sex, progressive MS course, Expanded Disability Status Scale, disease duration, body mass index, comorbidities, and recent methylprednisolone use, therapy with an anti-CD20 agent (ocrelizumab or rituximab) was significantly associated (odds ratio [OR] = 2.37, 95% confidence interval [CI] = 1.18-4.74, p = 0.015) with increased risk of severe COVID-19. Recent use (<1 month) of methylprednisolone was also associated with a worse outcome (OR = 5.24, 95% CI = 2.20-12.53, p = 0.001). Results were confirmed by the PS-weighted analysis and by all the sensitivity analyses.
Interpretation: This study showed an acceptable level of safety of therapies with a broad array of mechanisms of action. However, some specific elements of risk emerged. These will need to be considered while the COVID-19 pandemic persists
Prospective validation of the CLIP score: a new prognostic system for patient with cirrhosis and hepatocellular carcinoma
Prognosis of patients with cirrhosis and hepatocellular carcinoma (HCC) depends on both residual liver function and tumor extension. The CLIP score includes Child-Pugh stage, tumor morphology and extension, serum alfa-fetoprotein (AFP) levels, and portal vein thrombosis. We externally validated the CLIP score and compared its discriminatory ability and predictive power with that of the Okuda staging system in 196 patients with cirrhosis and HCC prospectively enrolled in a randomized trial. No significant associations were found between the CLIP score and the age, sex, and pattern of viral infection. There was a strong correlation between the CLIP score and the Okuda stage, As of June 1999, 150 patients (76.5%) had died. Median survival time was 11 months, overall, and it was 36, 22, 9, 7, and 3 months for CLIP categories 0, 1, 2, 3, and 4 to 6, respectively. In multivariate analysis, the CLIP score had additional explanatory power above that of the Okuda stage. This was true for both patients treated with locoregional therapy or not. A quantitative estimation of 2-year survival predictive power showed that the CLIP score explained 37% of survival variability, compared with 21% explained by Okuda stage. In conclusion, the CLIP score, compared with the Okuda staging system, gives more accurate prognostic information, is statistically more efficient, and has a greater survival predictive power. It could be useful in treatment planning by improving baseline prognostic evaluation of patients with RCC, and could be used in prospective therapeutic trials as a stratification variable, reducing the variability of results owing to patient selection
Desechos de vinificación como inhibidores de biopelículas de Staphylococcus aureus
Staphylococcus aureus is a well-known pathogen living as biofilm in a wide variety of environments and represents a severe risk of food contamination. The present study focused on the antibiofilm capacity of pomace extracts of different polarities and different varietals against two strains of S. aureus. Wine pomace of three varietals (Bonarda, Tannat, and Malbec) from Cafayate, Argentine, at two concentrations (10 and 100 µg/mL) was used to inhibit biofilm formation (BF) and preformed biofilm of S. aureus ATCC 6538 and LVP63 strains. Extractions were carried out with solvents of increasing polarity (chloroform, ethyl acetate, and ethanol). The ethyl acetate and ethanolic pomace extracts of the Tannat varietal were the most effective in reducing the BF formation in S. aureus without affecting planktonic growth. The extracts of Malbec and Tannat diminish the biofilm metabolic activity up to 70%. Likewise, the polar Tannat extracts and the mixture pomace disrupt the preformed BF in both S. aureus strains.
These residues can be used as a natural alternative source for the inhibition of pathogenic bacteria in the food industry and reduce the impact of these agro-industrial wastes on the environmentStaphylococcus aureus es un patógeno conocido que forma biopelículas en una amplia variedad de entornos y representa un riesgo severo de contaminación de los alimentos. El presente estudio se centró en la determinación de las capacidades antibiofilm de extractos de orujo procedentes de diferentes varietales de diferentes polaridades, procedentes de Cafayate, Argentina, frente a dos cepas de S. aureus. Se utilizaron orujos de tres varietales regionales (Bonarda, Tannat y Malbec) para inhibir la formación de biofilm (BF) o tratar una biopelícula formada. Se realizaron extracciones con solventes de polaridad creciente (cloroformo, acetato de etilo y etanol) y se enfrentaron 10 y 100 µg/mL de extractos a las cepas de S. aureus ATCC 6538 y LVP63. Los extractos acetato de etilo y etanólicos de orujo del varietal Tannat fueron los más efectivos para disminuir la formación de BF en S. aureus sin afectar el crecimiento planctónico. Respecto a los efectos sobre la biopelícula preformada, los extractos de los varietales Malbec y Tannat disminuyeron la actividad metabólica hasta un 70% y los extractos polares de Tannat y la mezcla de orujos disgregaron hasta un 65% el BF preformado por ambas cepas S. aureus. Por lo tanto, la reutilización de estos desechos agroindustriales se plantea como una alternativa natural para combatir bacterias patógenas en la industria alimentaria, disminuyendo el impacto de estos residuos agroindustriales en el ambiente y convirtiendo a estos desechos en un bioproducto, económicamente, rentable
Local levels of carbon monoxide in the urban air of San Miguel de Tucumán, Argentina
El monóxido de carbono (CO), gas altamente tóxico, es uno de los contaminantes atmosféricos más comunes y ampliamente distribuidos. En San Miguel de Tucumán, Argentina, las principales fuentes de emisión son los motores de vehículos y los incendios producidos por la quema de cañaverales. El objetivo de la presente investigación fue evaluar los niveles locales de concentración de CO en el aire urbano de San Miguel de Tucumán durante un período de trece años. Se seleccionaron cuatro estaciones de monitoreo con alta concentración poblacional. Se emplearon instrumentos de medición Testo 625, con sonda específica para CO. Las mediciones se realizaron en los meses de septiembre, octubre y noviembre durante el período 2003-2015. Las concentraciones de CO se compararon empleando análisis de la varianza de Kruskal-Wallis y postest de Conover al 5 % de significación. Se consideraron valores mínimos, máximos y percentiles P25, P50 y P75. Resultados: No se observaron diferencias significativas en las concentraciones anuales de CO (p = 0,7177), con min = 24 ppm, P25 = 28 ppm, P50 = 28,9 ppm, P75 = 32 ppm y máximo = 38 ppm. Con diferencias significativas en las concentraciones de CO (p < 0,001), según mes y estación de muestreo. Los mayores valores fueron detectados en el mes de noviembre en Estación 4, con min = 27,0 ppm, P25 = 30,7 ppm, P50 = 31,0 ppm, P75 = 33,2 ppm y máximo = 38,0 ppm. La ciudad de San Miguel de Tucumán se encuentra en zona montañosa, con escaso movimiento de aire, lo que determina una marcada acumulación de contaminantes atmosféricos, con concentraciones de CO elevadas en el microcentro de esta ciudad.Carbon monoxide, a highly toxic gas, is one of the most common and widely distributed air pollutants; in San Miguel de Tucumán, Argentina, the main sources of emission are the vehicle engines and the fire produced by the burning of cane fields. The objective was to evaluate the local levels of carbon monoxide (CO) concentration in the urban air of San Miguel de Tucumán during a period of 13 years. Four monitoring stations with high population concentration were selected. Testo 625 measuring instruments with specific probe for CO were used. The measurements were made during the months of September, October and November during the period 2003-2015. The concentrations of CO were compared using Variance analysis of Kruskal & Wallis and Conover post-test at 5 % significance. Minimum, maximum and Percentiles values (P25, P50 and P75) were considered. Results: No significant differences were observed in annual CO concentrations (p = 0.7177), with min = 24ppm, P25 = 28 ppm, P50 =28.9 ppm, P75 = 32 ppm and maximum = 38 ppm. With significant differences in CO concentrations (p <0.001) according to month and sampling season, higher values were detected in the month of November in Station 4 with min=27.0ppm, P25=30.7 ppm, P50=31.0 ppm, P75=33.2 ppm and maximum=38.0 ppm. Conclusion: The City of San Miguel de Tucumán is located in a mountainous area with little air movement, which means it has a notable accumulation of atmospheric pollutants, with high concentrations of CO in the microcenter of this city