70-nm-bandwidth achromatic waveguide coupler

We report a general approach to the design of broadband waveguide couplers. A double-parallel grating assembly is used to cancel the first chromatic order, and a proper choice of prism glass and base angle is made to compensate for the second chromatic order. The technique was applied to a Corning glass 7059 waveguide, and a spectral bandwidth of 70 nm was measured by the use of two complementary procedures.     

The Sedentary Lifestyle and Masticatory Dysfunction: Time to Review the Contribution to Age-Associated Cognitive Decline and Astrocyte Morphotypes in the Dentate Gyrus

As aging and cognitive decline progresses, the impact of a sedentary lifestyle on the appearance of environment-dependent cellular morphologies in the brain becomes more apparent. Sedentary living is also associated with poor oral health, which is known to correlate with the rate of cognitive decline. Here, we will review the evidence for the interplay between mastication and environmental enrichment and assess the impact of each on the structure of the brain. In previous studies, we explored the relationship between behavior and the morphological features of dentate gyrus glial fibrillary acidic protein (GFAP)-positive astrocytes during aging in contrasting environments and in the context of induced masticatory dysfunction. Hierarchical cluster and discriminant analysis of GFAP-positive astrocytes from the dentate gyrus molecular layer revealed that the proportion of AST1 (astrocyte arbors with greater complexity phenotype) and AST2 (lower complexity) are differentially affected by environment, aging and masticatory dysfunction, but the relationship is not straightforward. Here we re-evaluated our previous reconstructions by comparing dorsal and ventral astrocyte morphologies in the dentate gyrus, and we found that morphological complexity was the variable that contributed most to cluster formation across the experimental groups. In general, reducing masticatory activity increases astrocyte morphological complexity, and the effect is most marked in the ventral dentate gyrus, whereas the effect of environment was more marked in the dorsal dentate gyrus. All morphotypes retained their basic structural organization in intact tissue, suggesting that they are subtypes with a non-proliferative astrocyte profile. In summary, the increased complexity of astrocytes in situations where neuronal loss and behavioral deficits are present is counterintuitive, but highlights the need to better understand the role of the astrocyte in these conditions.     

Gravel deposits survey in south central Brazil

This paper deals with the influence of discontinuous particle-size distribution on the basic properties of asphaltic concrete. New particle-size curves were obtained by removing the fine, medium and coarse material connected with one or two successive sieves. Consequently the following characteristics have been examined: stability, deformation and voids of compacted asphaltic concrete according to the Greek specifications. The results showed that a high degree of flexibility capable of removing part of the aggregate exists. In that case the values of tests present positive or negative results which are also influenced by the existing proportion of bitumen. Thus a revision of specifications concerned with particle-size distribution might be possible.     

Volatile compounds contribution of Hanseniaspora guilliermondii and Hanseniaspora uvarum during red wine vinifications

This work aims to investigate the contribution of a selected non-Saccharomyces yeast species, Hanseniaspora guilliermondii, to higher alcohols, esters, fatty acids and heavy sulphur compounds composition of red wine. Red grape must vinifications of 100 l were performed and an inoculated fermentation with H. guilliermondii was compared to a spontaneous fermentation. The presence of apiculate yeasts was observed in both fermentations; however, Hanseniaspora uvarum was the only apiculate yeast isolated from the spontaneous fermentation. Apiculate yeasts dominated the fermentation until an ethanol concentration of 6% (v/v) was attained and remained in considerable high levels for an ethanol concentration of 12.5% (v/v). The grape must inoculated with H. guilliermondii led to the production of wine with higher concentrations of 1-propanol, 2-phenylethyl acetate and 3-(methylthio)propionic acid, and lower amounts of ethyl hexanoate, pentanoic acid, free fatty acids, 2-methyltetrahydrothiophen-3-one and acetic acid-3-(methylthio)propyl ester, than wine resulting from the spontaneous fermentation. The present study shows that the use of specific apiculate yeasts in grape must fermentations may lead to the production of wines with different chemical profiles, emphasising the importance of Hanseniaspora yeasts as mixed starter cultures with Saccharomyces cerevisiae, in winemaking.     

Metallization and investigation of electrical properties of in vitro recrystallized mSbsC-eGFP assemblies

Surface layer (SL) proteins are self-assembling nanosized arrays which can be recrystallized in solution or on surfaces. In this paper, we investigate the metallization, contact potential difference and conductivity of in vitro recrystallized mSbsC-eGFP tube-like assemblies for possible applications in nanobiotechnology. Treatment of mSbsC-eGFP tube-like structures with 150 mM Pt salt solution resulted in the formation of metallized SL assemblies decorated with Pt nanoparticles (? > 3 nm) which were closely packed and aggregated into metal clusters. Kelvin probe force microscopy (KPFM) measurements revealed that metallized and unmetallized SL templates showed different surface potential behaviours, demonstrating that the metal coating changes the electrostatic surface characteristics of SL assemblies. In situ conductivity measurements showed that unmetallized SL assemblies were not conductive. Metallized samples showed linear I-V dependence between - 1 and + 1 V with a conductivity of ～ 10(3) S m( - 1).     

Approach to prophylactic measures for central venous catheter‐related infections in hemodialysis: A critical review

Vascular access is the major risk factor for bacteremia, hospitalization, and mortality among hemodialysis (HD) patients. The type of vascular access most associated with bloodstream infection is central venous catheter (CVC). The incidence of catheter‐related bacteremia ranges between 0.6 and 6.5 episodes per 1000 catheter days and increases linearly with the duration of catheter use. Given the high prevalence of CVC use and its direct association with catheter‐related bacteremia, which adversely impacts morbidity and mortality rates and costs among HD patients, several prevention measures aimed at reducing the rates of CVC‐related infections have been proposed and implemented. As a result, a large number of clinical trials, systematic reviews, and meta‐analyses have been conducted in order to assess the effectiveness, clinical applicability, and long‐term adverse effects of such measures. In the following article, prophylactic measures against CVC‐related infections in HD patients and their possible advantages and limitations will be discussed, and the more recent literature on clinical experience with prophylactic antimicrobial lock therapy in HD CVCs will be reviewed.     

Statistical characterization of P2P-TV services and users

P2P-TV systems will certainly contribute to innovate the broadcast TV concept by allowing ubiquitous access to a practically unlimited number of channels, representing an important step forward in the direction of the Anything/Anyone/Anywhere/Anytime communication paradigm of future Internet applications. Since its deployment, P2P-TV has already attracted millions of users and it is expected to grow exponentially in the near future, both in terms of the number and diversity of their clients. Analyzing the behavior of P2P-TV systems and users and characterizing the generated traffic are fundamental steps to understand and evaluate the potential impacts of these applications on the underlying transport network. In this paper, a set of intensive measurements was conducted in a residential Internet access environment in order to obtain a good insight over the mechanisms that govern data transfer on some of the most important P2P-TV applications (TVants, SOPCast and TVU Player) and understand the most important advances they have suffered in the latest years. Among other relevant findings, the analysis showed that peer location does not seem to be exploited by any of the studied applications and P2P-TV is already a worldwide phenomenon: using the three selected applications during 12 days of experiments, peers from 177 different countries all over the world were contacted, including countries where the interest for English-spoken channels was not so likely.     

Influence of Inflow Nonstationarity on the Multipurpose Optimal Operation of Hydropower Plants Using Nonlinear Programming

Water Resources Management - One of the greatest challenges in the electricity generation sector is to operate hydrothermal plants in view of the randomness of hydrological events and climate...