Astrophysical properties of binary star clusters in the Small Magellanic Cloud

To study the evolution of binary star clusters we have imaged 7 systems in the Small Magellanic Cloud with SOAR 4-m telescope using B and V filters. The sample contains pairs with well-separated components (d < 30 pc) as well as systems that apparently merged, as evidenced by their unusual structures. By employing isochrone fittings to their CMDs we have determined reddening, age and metallicity and by fitting King models to their radial stellar density profile we have estimated core radius. Disturbances of the density profile are interpreted as an evidence of interaction. Circunstances as distances between components and their age difference are addressed in terms of the timescales involved to access the physical connection of the system. In two cases the age difference is above 50 Myr, which suggests chance alignment, capture or sequential star formation.Comment: 4 pages, 1 figure. To appear in online version of Proc. IAU Symp. 266 (Star clusters), eds. R. de Grijs and J. Lepin

Normal Stress Distribution of Rough Surfaces in Contact

We study numerically the stress distribution on the interface between two thick elastic media bounded by interfaces that include spatially correlated asperities. The interface roughness is described using the self-affine topography that is observed over a very wide range of scales from fractures to faults. We analyse the correlation properties of the normal stress distribution when the rough surfaces have been brought into full contact. The self affinity of the rough surfaces is described by a Hurst exponent H. We find that the normal stress field is also self affine, but with a Hurst exponent H-1. Fluctations of the normal stress are shown to be important, especially at local scales with anti-persistent correlations.Comment: 11 pages LaTeX, 4 Postscript figures, submitted to Geophysical Research Letter

Superdiffusive Conduction: AC Conductivity with Correlated Noise

We present evidence of the existence of a superdiffusive regime in systems with correlated disorder for which localization is suppressed. An expression for anomalous electrical conductivity at low frequencies is found by using a generalized Langevin equation whose memory function accounts for the interactions between the carriers. New mechanisms inducing a superdiffusive conductivity are discussed and experimental possibilities for observing that phenomenon in nanotubes and superlattices are presented.Comment: 7 pages, no figure

X-DLVO interactions between Nanocolloidal Magnetic Particles : the quantitative interpretation of the pH-dependent phase diagram of EDL-MF

The phase behavior of acidic samples of EDL-MF based on cobalt ferrite nanoparticles with controlled mean sizes was investigated at constant temperature and in absence of magnetic field. By monitoring the anoparticle charge by pH adjustments, we constructed an experimental pH-dependent phase diagram for all samples that revealed sol, gel thixotropic or coagulated phases in different pH regions. Then, by using an extended DLVO potential we analyzed quantitatively the observed phase diagram in function of pH and nanoparticle mean size

Stand dynamics modulate water cycling and mortality risk in droughted tropical forest

Transpiration from the Amazon rainforest generates an essential water source at a global and local scale. However, changes in rainforest function with climate change can disrupt this process, causing significant reductions in precipitation across Amazonia, and potentially at a global scale. We report the only study of forest transpiration following a long-term (>10 year) experimental drought treatment in Amazonian forest. After 15 years of receiving half the normal rainfall, drought-related tree mortality caused total forest transpiration to decrease by 30%. However, the surviving droughted trees maintained or increased transpiration because of reduced competition for water and increased light availability, which is consistent with increased growth rates. Consequently, the amount of water supplied as rainfall reaching the soil and directly recycled as transpiration increased to 100%. This value was 25% greater than for adjacent nondroughted forest. If these drought conditions were accompanied by a modest increase in temperature (e.g., 1.5°C), water demand would exceed supply, making the forest more prone to increased tree mortality.Peer reviewe

Os limites da recuperação econômica da Zona do Euro (2008-2016)

sem informaçãoDesde a deflagração da crise global em 2008, os países da periferia da Zona do Euro têm enfrentado grandes dificuldades para viabilizar o processo de recuperação dos níveis de produto, renda e emprego. O artigo discute esse processo e argumenta que a exau21125131sem informaçãosem informaçãosem informaçãoOs autores agradecem as sugestões realizadas pelos pareceristas anônimos da revista, isentando-os, naturalmente, de eventuais erros e omissõe

Effects of different resistance training frequencies on flexibility in older women

Objective The main purpose of the investigation reported here was to analyze the effect of resistance training (RT) performed at different weekly frequencies on flexibility in older women. Participants and methods Fifty-three older women (≥60 years old) were randomly assigned to perform RT either two (n=28; group “G2x”), or three (n=25; group “G3x”) times per week. The RT program comprised eight exercises in which the participants performed one set of 10–15 repetitions maximum for a period of 12 weeks. Anthropometric, body-composition, and flexibility measurements were made at baseline and post-study. The flexibility measurements were obtained by a fleximeter. Results A significant group-by-time interaction (P\u3c0.01) was observed for frontal hip flexion, in which G3x showed a higher increase than G2x (+12.8% and +3.0%, respectively). Both groups increased flexibility in cervical extension (G2x=+19.1%, G3x=+20.0%), right hip flexion (G2x=+14.6%, G3x=+15.9%), and left hip flexion (G2x=+25.7%, G3x=+19.2%), with no statistical difference between groups. No statistically significant differences were noted for the increase in skeletal muscle mass between training three versus two times a week (+7.4% vs +4.4%, respectively). Conclusion Twelve weeks of RT improves the flexibility of different joint movements in older women, and the higher frequency induces greater increases for frontal hip flexion

Differences in xylem and leaf hydraulic traits explain differences in drought tolerance among mature Amazon rainforest trees

Considerable uncertainty surrounds the impacts of anthropogenic climate change on the composition and structure of Amazon forests. Building upon results from two large-scale ecosystem drought experiments in the eastern Brazilian Amazon that observed increases in mortality rates among some tree species but not others, in this study we investigate the physiological traits underpinning these differential demographic responses. Xylem pressure at 50% conductivity (xylem-P50 ), leaf turgor loss point (TLP), cellular osmotic potential (πo ), and cellular bulk modulus of elasticity (ε), all traits mechanistically linked to drought tolerance, were measured on upper canopy branches and leaves of mature trees from selected species growing at the two drought experiment sites. Each species was placed a priori into one of four plant functional type (PFT) categories: drought-tolerant versus drought-intolerant based on observed mortality rates, and subdivided into early- versus late-successional based on wood density. We tested the hypotheses that the measured traits would be significantly different between the four PFTs and that they would be spatially conserved across the two experimental sites. Xylem-P50 , TLP, and πo , but not ε, occurred at significantly higher water potentials for the drought-intolerant PFT compared to the drought-tolerant PFT; however, there were no significant differences between the early- and late-successional PFTs. These results suggest that these three traits are important for determining drought tolerance, and are largely independent of wood density-a trait commonly associated with successional status. Differences in these physiological traits that occurred between the drought-tolerant and drought-intolerant PFTs were conserved between the two research sites, even though they had different soil types and dry-season lengths. This more detailed understanding of how xylem and leaf hydraulic traits vary between co-occuring drought-tolerant and drought-intolerant tropical tree species promises to facilitate a much-needed improvement in the representation of plant hydraulics within terrestrial ecosystem and biosphere models, which will enhance our ability to make robust predictions of how future changes in climate will affect tropical forests

Brewers' spent grain as substrates for production of cellulolytic and hemicellulolytic enzymes by different Aspergillus species

Brewers' spent grain (BSG) is the major by-product of the brewing industry, representing around 85% of the total by-products generated. It is a lignocellulosic material containing about 38% cellulose, 29% hemicellulose, chiefly arabinoxylans, and 13% lignin. The production of cellulolytic and hemicellulolytic enzymes using this material as substrate represent an eco-friendly strategy for the lignocellulosic biomass hydrolysis, generating fermentable sugars that can be converted into high- added value products, such as bioethanol, lactic acid, xylitol and others. Thus, this work aimed to evaluate the potential of cellulolytic and hemicellulolytic enzymes production by some Aspergillus species cultivated in BSG. Fungi were grown in minimum media, pH 6.5, with 1% BSG and inoculum was done with 107spores/mL, cultivated at 30°C, 120 rpm, for 5 days. Every 24 hours 2 mL of the samples were collected. The enzymatic activity was performed after the incubation of the crude extract with 1% Linear arabinan, Xylan from beechwood, Xyloglucan, Locust bean gum and CMC, at 50°C for 60 minutes and the reducing sugars were determined using dinitrosalicylic acid (DNS). Synthetic substrates (2 mM of PNP--L-arabinofuranoside, PNP--D-xylopyranoside, PNP--Dglucopyranoside and PNP--D-cellobioside) were also used at the same conditions. The extract from A. niveus showed the best arabinanase (0.284 U/mL) and -glucosidase (0.126 U/mL) activities after 48 and 96 hours of cultivation, respectively. On the other hand, the extract from A. brasiliensis presented the best activities of -L-arabinofuranosidase (0.129 U/mL), -xylosidase (0.265 U/mL) and xylanase (2.15 U/mL) when cultivated for 48 hours. After 72 hours, this fungus also showed the best activities for xyloglucanase (1.06 U/mL), mannanase (0.617 U/mL) and endoglucanase (0.254 U/mL). The extract produced by A. flavus presented the best cellobiohydrolase activity with 0.113 U/mL after 120 hours of cultivation. It is important to mention that A. awamori, A. clavatus and A. terreus also showed good levels of different enzymes produced but they were not the best producers. These data suggest the great potential of different cellulolytic and hemicellulolytic enzymes production using BSG as substrate, which represents an eco-friendly destination for the residues and can generate high-added value products with great biotechnological application.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Institutos Nacionais de Ciência e Tecnologia (INCT)Fundação para a Ciência e a Tecnologia (FCT)info:eu-repo/semantics/publishedVersio