Life stress and the long-term treatment course of recurrent depression: III. Nonsevere life events predict recurrence for medicated patients over 3 years.

Research has consistently documented the significance of severe life events for onset of major depression. Theory, however, suggests other forms of stress are relevant for depression's recurrence. Nonsevere life events were tested in relation to depression for 126 patients with recurrent depression in a 3-year randomized maintenance protocol. Life stress was assessed every 12 weeks and rated along dimensions of severity, focus, and independence. A significant interaction between specific types of nonsevere life events and medication was found. For medicated patients, subject-focused independent nonsevere life events predicted recurrence; for unmedicated patients, these events predicted fewer recurrences. Other nonsevere life events did not predict recurrence. The findings underscore the potential importance of specific stressors for triggering recurrences of depression. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Ultra wideband: the radio link of the future?

A new data transmission technique is about to create a revolution in the field of wireless local area networks. This new method, called Ultra Wideband, is based on the transmission of data through the communication channel below the noise floor. It involves transmitting very short duration pulses, which has the effect of spreading the signal energy across a wide frequency range. The objective of this article is to report on the state of the art in this research area, and to outline the main advantages of this promising data transmission method.     

PEDOT:PSS coating on specialty papers: Process optimization and effects of surface properties on electrical performances

In this study, the effects of different paper substrates on the electrical resistance of conducting polymer films are reported. A novel method of bar coating is used for the fabrication of organic conductive films on various substrates. Solutions to improve the continuity of conductive thin film in order to enhance the electrical properties are demonstrated. In order to compare the capability of these different substrates for a potential use in the organic electronic field, sheet resistance measurements were made. It is emphasized that substrate roughness and surface energy are two fundamental parameters, due to their significant impact on sheet resistance. Two methods to overcome bad paper surface properties are proposed. The first consists in the superimposition of conductive polymer layers and the second in the use of a protective layer.     

Dynamics of food preferences: a case study with chewing gums

The dynamics of food perception is critical in sensory science. However, although much research deals with time–intensity measurement as a tool for analytical sensory evaluation, it is striking that almost no published research investigates the dynamics of hedonic responses. Here we studied how consumers scored mint flavored sugar-free gums when the test duration varied. Six coated dragée-like gums from the French market were tested by each consumer according to three test conditions: 1 min of chewing, 5 min and half-an-hour. One and five minute tests took place in the sensory lab evaluation booths whereas consumers were free to move about for the 30 min modality. All consumers thus participated to a total of 18 sessions. Our main finding is that the average liking varies with the test duration but that this variation differs for the six products in a way that one of the initially least liked products becomes the most liked when it is chewed during 30 min. Also, the individual liking patterns and the resulting consumer segmentation varied widely across the three test conditions. Additionally, a Flash profile was performed with experienced subjects in an attempt to relate the observed differences in liking to the gum sensory characteristics. Trigeminal-related sensations seem to play an important role in these changes. Clearly such aspects are to be taken into account for new product development and market analysis. This kind of concerns may be even more challenging for hedonic evaluation of many non-food products.     

Biomass and volume yield after 6 years in multiclonal hybrid poplar riparian buffer strips

In this paper the potential of five hybrid poplar clones (Populus spp.) to provide biomass and wood volume in the riparian zone is assessed in four agroecosystems of southern Quebec (Canada). For all variables measured, significant Site effects were detected. Survival, biomass yield and volume yield were highest at the Bromptonville site. After 6 years of growth, total aboveground biomass production (stems + branches + leaves) reached 112.8 tDM/ha and total leafless biomass production (stems + branches) reached 101.1 tDM/ha at this site, while stem wood volume attained 237.5 m³/ha. Yields as low as 14.2 tDM/ha for total biomass and 24.8 m³/ha for total stem volume were also observed at the Magog site. Highest yields were obtained on the most fertile sites, particularly in terms of NO₃ supply rate. Mean stem volume per tree was highly correlated with NO₃ supply rate in soils (R² = 0.58, p < 0.001). Clone effects were also detected for most of the variables measured. Total aboveground biomass and total stem volume production were high for clone 3729 (Populus nigra × P. maximowiczii) (73.1 tDM/ha and 134.2 m³/ha), although not statistically different from clone 915311 (P. maximowiczii × P. balsamifera). However, mean whole-tree biomass (including leaves) was significantly higher for clone 3729 (38.8 kgDM/tree). Multifunctional agroforestry systems such as hybrid poplar riparian buffer strips are among the most sustainable ways to produce a high amount of biomass and wood in a short time period, while contributing to alleviate environmental problems such as agricultural non-point source pollution.     

The ultrafiltration molecular weight cut-off has a limited effect on the concentration and protein profile during preparation of human milk protein concentrates

Optimizing protein intake for very low birth weight (<1,500 g) infants is fundamental to prevent faltering postnatal growth with the potential association of impaired neurodevelopment. The protein content of human milk is not sufficient to support the growth of very low birth weight infants. To meet their elevated protein requirements, human milk is currently fortified using typically bovine milk-based protein isolates (>85% on a dry basis). However, these products have several limitations for use in this vulnerable population. To overcome the shortcomings of bovine milk-based protein supplement, a human milk protein concentrate (HMPC) was developed. In preliminary attempts using 10 kDa ultrafiltration (UF) membranes, it was not possible to reach the protein content of commercial protein isolates, presumably due to the retention of human milk oligosaccharides (HMO). Consequently, it was hypothesized that the use of a UF membrane with a higher molecular weight cut-off (50 kDa rather than 10 kDa) could improve the transmission of carbohydrates, including HMO, in the permeate, thus increasing the protein purity of the subsequent HMPC. The results showed that permeate fluxes during the concentration step were similar to either UF molecular weight cut-off, but the 50-kDa membrane had a higher permeate flux during the diafiltration sequence. However, it was not sufficient to increase the protein purity of the human milk retentate, as both membranes generated HMPC with similar protein contents of 48.8% (10 kDa) and 50% (50 kDa) on a dry basis. This result was related to the high retention of HMO, mainly during the concentration step, although the diafiltration step was efficient to decrease their content in the HMPC. As the major bioactive proteins (lactoferrin, lysozyme, bile salt stimulated lipase, and α1-antitrypsin) in human milk were detected in both HMPC, the 50-kDa membrane seems the most appropriate to the preparation of HMPC in terms of permeation flux values. However, improving the separation of HMO from proteins is essential to increase the protein purity of HMPC.     

Detecting instability in the volatility of carbon prices

This article investigates the presence of outliers in the volatility of carbon prices. We compute three different measures of volatility for European Union Allowances, based on daily data (EGARCH model), option prices (implied volatility), and intraday data (realized volatility). Based on the methodology developed by Zeileis et al. (2003) and Zeileis (2006), we detect instability in the volatility of carbon prices based on two kinds of tests: retrospective tests (OLS-/Recursive-based CUSUM processes, F-statistics, and residual sum of squares), and forward-looking tests (by monitoring structural changes recursively or with moving estimates). We show evidence of strong shifts mainly for the EGARCH and IV models during the time period. Overall, we suggest that yearly compliance events, and growing uncertainties in post-Kyoto international agreements, may explain the instability in the volatility of carbon prices.     

A model of carbon price interactions with macroeconomic and energy dynamics

This paper develops a model of carbon pricing by considering two fundamental drivers of European Union Allowances: economic activity and energy prices. On the one hand, economic activity is proxied by aggregated industrial production in the EU 27 (as it provides the best performance in a preliminary forecasting exercise vs. other indicators). On the other hand, brent, natural gas and coal prices are selected as being the main carbon price drivers (as highlighted by previous literature). The interactions between the macroeconomic and energy spheres are captured in a Markov-switching VAR model with two states that is able to reproduce the ‘boom–bust’ business cycle (Hamilton (1989)). First, industrial production is found to impact positively (negatively) the carbon market during periods of economic expansion (recession), thereby confirming the existence of a link between the macroeconomy and the price of carbon. Second, the brent price is confirmed to be the leader in price formation among energy markets (Bachmeier and Griffin (2006)), as it impacts other variables through the structure of the Markov-switching model. Taken together, these results uncover new interactions between the recently created EU emissions market and the pre-existing macroeconomic/energy environment.     

In vitro studies on interaction of rat pancreatic lipase and colipase with biliary lipids

Lipase and colipase were prepared separately from rat pancreatic juice, and their respective interaction with biliary lipids was investigated by gel filtration on agarose in the presence of a micellar solution of sodium taurocholate. It was found that the cofactor can associate with the biliary lipids, whereas the enzyme forms a high mol wt complex only in the presence of colipase. It is suggested that biliary phospholipids might participate in the in vivo formation of the enzyme-cofactor substrate complex at the triglyceride-water interface in the presence of bile salts.