1,191 research outputs found
Nearby Young, Active, Late-type Dwarfs in Gaia's First Data Release
The Galex Nearby Young Star Survey (GALNYSS) has yielded a sample of
2000 UV-selected objects that are candidate nearby (150 pc), young (age 10--100 Myr), late-type stars.
Here, we evaluate the distances and ages of the subsample of (19) GALNYSS stars
with Gaia Data Release 1 (DR1) parallax distances pc. The overall
youth of these 19 mid-K to early-M stars is readily apparent from their
positions relative to the loci of main sequence stars and giants in Gaia-based
color-magnitude and color-color diagrams constructed for all Galex- and
WISE-detected stars with parallax measurements included in DR1. The isochronal
ages of all 19 stars lie in the range 10--100 Myr. Comparison with
Li-based age estimates indicates a handful of these stars may be young
main-sequence binaries rather than pre-main sequence stars. Nine of the 19
objects have not previously been considered as nearby, young stars, and all but
one of these are found at declinations north of 30. The Gaia DR1
results presented here indicate that the GALNYSS sample includes several
hundred nearby, young stars, a substantial fraction of which have not been
previously recognized as having ages 100 Myr.Comment: 30 pages, 4 tables, 7 figures; to appear in The Astrophysical
Journal; 1st replacement to correct typos/omissions in Table 3 and
acknowledgments; 2nd replacement to incorporate corrections to ApJ proof
Is it possible measure reducing sugar in wines by Fehling Causse Bonnans method, without using neutral lead acetate?
El método oficial argentino para determinar el contenido de azúcares reductores en
mostos y vinos es el método Fehling Causse Bonnans. Este método implica la defecación
de la muestra para obtener una solución azucarada decolorada y límpida. Para ello
se emplea carbón activado y acetato de plomo. Son conocidos los efectos de la intoxicación
con plomo en seres humanos y animales, así como en el ambiente, de modo que
es necesario minimizar su uso para lograr una producción sustentable. Se analizaron
149 vinos y 67 mostos. En cada una de las muestras se efectuaron dos determinaciones de
azúcares reductores, diferenciadas por la forma de efectuar la defecación: a) empleando
5 mL de acetato de plomo al 25% y 0,5 g de carbón activado y b) empleando 5 mL de
agua destilada y 0,5 g de carbón activado. Los datos se procesaron efectuando análisis
de regresión simple lineal. Se concluye que puede eliminarse el uso de acetato de plomo
en el tratamiento previo de las muestras de mostos y vinos para determinar azúcares
reductores por el método de Fehling Causse Bonnans. La defecación de la muestra se
realiza empleando solo carbón vegetal activado. Esta modificación de la técnica original
permite eliminar el empleo de sales de plomo y la contaminación que ello implica, sin
incurrir en errores apreciables en la medida de los azúcares reductores.The Argentine official method to determine the content of reducing sugars in musts
and wines is the Causse Bonnans Fehling method. This method requires a sample
treatment to obtain a decolorized and clear solution. Activated charcoal and lead acetate
are used for this procedure. The effects of lead poisoning in humans, animals and the
environment are known, so it is necessary to minimize their use to achieve sustainable
production. Reducing sugars were analyzed in 149 wines and 67 grape musts. For each
sample, two different treatments were used: a) 5 mL of lead acetate at 25% and 0.5 g of
activated charcoal and b) adding 5 mL of distilled water and 0.5 g of activated carbon.
The data were processed by performing simple linear regression analysis. Lead acetate
can be eliminated in the pretreatment of must and wine samples to determine reducing
sugars by Fehling Bonnans Causse method. This modification of the original technique
eliminates the use of lead salts and pollution involved, without faults in the measurement
of the reducing sugars.Fil: Cobos, David.
Universidad Tecnológica Nacional (Argentina). Facultad Regional MendozaFil: Germano, Laura.
Instituto Nacional de Vitivinicultura (Argentina)Fil: Malovini, Emiliano.
Universidad Nacional de Cuyo. Facultad de Ciencias AgrariasFil: Paladino, Silvia.
Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Cátedra de Enología I
Efeitos do treinamento intervalado de alta intensidade e/ou de força sobre o consumo de oxigênio de pico e limiares ventilatórios em diabéticos tipo 1
Fundamentos: A atividade física regular pode ser considerada uma das melhores ferramentas não farmacológicas no tratamento do diabetes mellitus tipo 1 (DM1). Os limiares ventilatórios (LV) e o consumo de oxigênio de pico (VO2pico) podem indicar adaptações metabólicas provocadas por protocolos de treinamento físico e o nível de aptidão física dos indivíduos. Objetivos: Analisar os efeitos de diferentes treinamentos sobre os LV e o VO2pico de indivíduos com DM1. Métodos: Ensaio clínico randomizado incluindo 27 indivíduos com DM1, divididos em três grupos: treinamento de força (TF), treinamento intervalado de alta intensidade (HIIT) e a combinação de ambos (TF+HIIT). As sessões de treinamento foram realizadas em cicloergômetro e/ou aparelhos de musculação. Resultados: Aumento de 19,4% na média do VO2pico (p<0,005), 20,6% na carga máxima e 10,9% no tempo total de teste (TTT) no grupo HIIT. Os três grupos obtiveram aumento na carga máxima (9,8% no grupo TF e 16,6% no grupo TF+HIIT), e no TTT (5,2% no grupo TF e 14,2% no grupo TF+HIIT) (p<0,001). A carga média no segundo LV aumentou 5,9% no grupo TF (p = 0,017). Conclusão: A escolha do HIIT como método de treinamento pode acarretar melhoras nas variáveis cardiorrespiratórias dessa população, o que impacta na redução do risco de desenvolvimento de complicações associadas ao DM1 e melhora na qualidade de vida. Quanto ao TF e o TF+HIIT, são necessárias mais investigações para confirmação de sua eficácia na melhora cardiorrespiratória e no deslocamento dos limiares ventilatórios.Background: Regular physical activity may be considered one of the best non-pharmacological tools in the treatment of type 1 diabetes mellitus (T1DM). In this way, ventilatory thresholds (VT) and peak oxygen uptake (VO2peak) may serve as indicators of metabolic adaptations caused by exercise training protocols and the fitness level of individuals. Goals: To analyze the effects of different training protocols on VT and VO2peak of T1DM patients. Methods: Randomized clinical trial including 27 T1DM patients, divided into three groups: strength training (ST), high-intensity interval training (HIIT) and their combination (ST+HIIT). Sessions training were performed in cycle ergometers and/or exercise machines at a gym. Results: It was observed a higher VO2peak (19.4%; p<0.005), maximal workload (20.6%) and time-to-exhaustion (TTE) (10.9%) after HIIT. They were observed increased maximal total load (9.8% after ST and 16.6% after ST+HIIT), and on TTE (5.2% after ST and 14.2% after ST+HIIT) (p<0.001). Workload at VT2 increased 5.9% in the ST group (p = 0.017). Conclusion: The choice of HIIT as training method can induce improvements in the cardiorrespiratory outcomes of this population, which impacts in a reduced risk of complications associated to DM1 and improved quality of life. Reagarding ST and ST+HIIT, more investigations are needed to confirm its efficacy in improved cardiorrespiratory fitness and ventilarory thresholds
Co-infection of Streptococcus pneumoniae in Respiratory Infections Caused by SARS-CoV-2
Abstract: Viral respiratory infections are often associated with bacterial co-infections that often lead
to increased severity and mortality of the disease. During the recent pandemic caused by severe acute
respiratory syndrome coronavirus 2 (SARS-CoV-2), hospitalized patients reported developing
secondary bacterial infections ranging from 0 to 40% of the cases. In the previous influenza pandemics,
Streptococcus pneumoniae was the most isolated bacterial pathogen causing increased mortality in
patients affected by viral pneumonia. Due to the difficulty to detect pneumococcal infection in SARSCoV-2 patients by a rapid clinical test, the real prevalence of S. pneumoniae might be underestimated,
and only a few cases have been documented so far. It has been estimated that 90% of patients admitted
to the Intensive Care Unit are empirically treated with antimicrobial. The application of more rapid and
sensitive diagnostic methods could help with targeted antibiotic therapy. Additionally, pneumococcal
vaccination of high-risk individuals could reduce bacterial pneumonia, hospital admissions, and
comorbidities associated with serious illness
Hydrocarbon-Contaminated Sites: Is There Something More Than Exophiala xenobiotica? New Insights into Black Fungal Diversity Using the Long Cold Incubation Method
Human-made hydrocarbon-rich environments are important reservoirs of microorganisms with specific degrading abilities and pathogenic potential. In particular, black fungi are of great interest, but their presence in the environment is frequently underestimated because they are difficult to isolate. In the frame of a biodiversity study from fuel-contaminated sites involving 30 diesel car tanks and 112 fuel pump dispensers (52 diesel and 60 gasoline, respectively), a total of 181 black fungal strains were isolated. The long cold incubation (LCI) of water-suspended samples, followed by plating on Dichloran Rose Bengal Chloramphenicol Agar (DRBC), gave isolation yields up to six times (6.6) higher than those of direct plating on DRBC, and those of enrichment with a phenolic mix. The sequencing of ITS and LSU-rDNA confirmed the dominance of potentially pathogenic fungi from the family Herpotrichiellaceae and Exophiala xenobiotica. Moreover, other opportunistic species were found, including E. opportunistica, E. oligosperma, E. phaeomuriformis, and Rhinocladiella similis. The recurrent presence of E. crusticola, Knufia epidermidis, Aureobasidium melanogenum, Cladosporium spp., and Scolecobasidium spp. was also recorded. Interestingly, 12% of total isolates, corresponding to 50% of taxa found (16/32), represent new species. All the novel taxa in this study were isolated by LCI. These findings suggest that black fungal diversity in hydrocarbon-rich niches remains largely unexplored and that LCI can be an efficient tool for further investigations.info:eu-repo/semantics/publishedVersio
¿Es posible determinar azúcares reductores en vinos por el método Fehling Causse Bonnans, sin utilizar acetato neutro de plomo?
The Argentine official method to determine the content of reducing sugars in musts and wines is the Causse Bonnans Fehling method. This method requires a sampletreatment to obtain a decolorized and clear solution. Activated charcoal and lead acetate are used for this procedure. The effects of lead poisoning in humans, animals and the environment are known, so it is necessary to minimize their use to achieve sustainable production. Reducing sugars were analyzed in 149 wines and 67 grape musts. For each sample, two different treatments were used: a) 5 mL of lead acetate at 25% and 0.5 g of activated charcoal and b) adding 5 mL of distilled water and 0.5 g of activated carbon. The data were processed by performing simple linear regression analysis. Lead acetate can be eliminated in the pretreatment of must and wine samples to determine reducing sugars by Fehling Bonnans Causse method. This modification of the original technique eliminates the use of lead salts and pollution involved, without faults in the measurement of the reducing sugars.El método oficial argentino para determinar el contenido de azúcares reductores en mostos y vinos es el método Fehling Causse Bonnans. Este método implica la defecación de la muestra para obtener una solución azucarada decolorada y límpida. Para ello se emplea carbón activado y acetato de plomo. Son conocidos los efectos de la intoxicación con plomo en seres humanos y animales, así como en el ambiente, de modo que es necesario minimizar su uso para lograr una producción sustentable. Se analizaron 149 vinos y 67 mostos. En cada una de las muestras se efectuaron dos determinaciones de azúcares reductores, diferenciadas por la forma de efectuar la defecación: a) empleando 5 mL de acetato de plomo al 25% y 0,5 g de carbón activado y b) empleando 5 mL de agua destilada y 0,5 g de carbón activado. Los datos se procesaron efectuando análisis de regresión simple lineal. Se concluye que puede eliminarse el uso de acetato de plomo en el tratamiento previo de las muestras de mostos y vinos para determinar azúcares reductores por el método de Fehling Causse Bonnans. La defecación de la muestra se realiza empleando solo carbón vegetal activado. Esta modificación de la técnica original permite eliminar el empleo de sales de plomo y la contaminación que ello implica, sinincurrir en errores apreciables en la medida de los azúcares reductores
The role of radial migration in open cluster and field star populations with Gaia dr3
The survival time of a star cluster depends on its total mass, density, and
thus size, as well as on the environment in which it was born and in which
lies. Its dynamical evolution is influenced by various factors such as
gravitational effects of the Galactic bar, spiral structures, and molecular
clouds. Overall, the factors that determine the longevity of a cluster are
complex and not fully understood. This study aims to investigate if open
clusters and field stars respond differently to the perturbations that cause
radial migration. In particular, we aim at understanding the nature of the
oldest surviving clusters. We compared the time evolution of the kinematic
properties of two Gaia DR3 samples: the first sample is composed of 40
open clusters and the second one of 66,000 MSTO field stars. Both
selected samples are composed of stars selected with the same quality
criterion, belonging to the thin disc, in a similar metallicity range, located
in the same Galactocentric region [7.5-9 kpc] and with ages >1 Gyr. We
performed a statistical analysis comparing the properties of the samples of
field stars and of open clusters. A qualitative comparison of kinematic and
orbital properties reveals that clusters younger than 2-3 Gyr are more
resistant to perturbations than field stars and they move along quasi-circular
orbits. Conversely, clusters older than approximately 3 Gyr have more eccentric
and inclined orbits than isolated stars in the same age range. Such orbits lead
them to reach higher elevations on the Galactic plane, maximising their
probability to survive several Gyr longer. A formal statistical analysis
reveals that there are differences among the time evolution of most of the
kinematic and orbital properties of field stars and open clusters. Our results
suggest that oldest survived clusters are usually more massive and move on
orbits with higher eccentricity.Comment: 13 pages, 20 figures, 2 tables. Article accepted for publication in
A&
In vitro Interactions between Streptococcus intermedius and Streptococcus salivarius K12 on a Titanium Cylindrical Surface
Peri-implantitis is a steadily rising disease and is caused by oral bacterial pathogens able to form biofilm on implant surfaces and peri-implant tissues, making antibiotics treatment less effective. The use of commercial probiotics against oral pathogens could serve as an alternative to prevent biofilm formation. Streptococcus intermedius is one of the early colonizers of biofilm formation in dental implants. The aim of this study was to model the interaction between S. intermedius and Streptococcus salivarius strain K12, a probiotic bacterium producing bacteriocins. S. intermedius was co-cultured with S. salivarius K12 in an in vitro model simulating the biofilm formation in a dental implant composed by a titanium cylinder system. Biofilm formation rate was assessed by Real-Time PCR quantification of bacterial count and expression levels of luxS gene, used in response to cell density in the biofilm. Biofilm formation, bacteriocin production, luxS expression patterns were found to be already expressed within the first 12 h. More importantly, S. salivarius K12 was able to counter the biofilm formation in a titanium cylinder under the tested condition. In conclusion, our dental implant model may be useful for exploring probiotic-pathogen interaction to find an alternative to antibiotics for peri-implantitis treatment
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