Response of macroinvertebrate and diatom communities to human‐induced physical alteration in mountain streams

It is generally argued that epilithic diatoms and macroinvertebrates are highly sensitive to changes in water quality, while only a few studies have been conducted on their response to physical disturbance. The main purpose of this research is to investigate whether these two communities respond to physical river disturbance like banks, substrate and flux alteration induced by human action. We sampled 12 high‐altitude streams in the Gran Paradiso National Park, a protected area where the main human activities are limited to hiking and high‐altitude pasture. The sampled stretches of the rivers were characterized with respect to their geomorphological features and possible human modifications. Water uptake for power supply, riverbed and bank modifications represented the main human activities which could determinate alterations in community structure and composition. Habitat structure was evaluated using the Southern European River Habitat (RHS–SE), while the biological status of the river has been estimated by means of the following biotic and diatomic indices: IBE, BMWP, ASPT, Ephemeroptera, Plecoptera and Trichoptera families (EPT) for macroinvertebrates, EPI‐D, IBD and IPS for diatoms. A general concordance between chemical parameters and structure of biological communities was observed. On the other hand, the RHS–SE highlighted the main geomorphological features and detected some slight physical alterations, as quantified by the indices Habitat Modification Score (HMS) and Habitat Quality Assessment (HQA). In short, our findings demonstrate that morphological alterations, even if slight, affect biological diversity and the presence of some specific taxa, while biological indices are independent of the level of physical modifications. Copyright © 2008 John Wiley & Sons, Ltd.     

Evidence-based interventions in school psychology: An illustration of Task Force coding criteria using single-participant research design.

Illustrates the application of the Task Force on Evidence-Based Interventions in School Psychology coding criteria using a single-participant research design study. Specifically, the authors review and evaluate a study by M. L. Kelley and A. P. McCain (1995) according to the Procedural and Coding Manual for Review of Evidence-Based Interventions (T. R. Kratochwill and K. C. Stoiber, this issue; see record 2003-01789-005). Following application of the Procedural and Coding Manual to the Kelley and McCain study, the authors conclude that this study possessed several important strengths, including a strong research design, identifiable intervention components, and strong intervention effects for several participants. Limitations to the study, in addition to issues regarding the evaluation of the single-participant investigation are discussed within the context of the coding criteria. Challenges in coding single-participant studies are presented in the context of future work for the Task Force on Evidence-Based Interventions in School Psychology. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Nitrogen and helium permeation tests of SiCf/SiC composites

The permeance of inert gases (N₂ and He) through coated SiC based ceramic composites both in form of tubes and discs has been measured, in particular SiC-SiC_f/SiC functionally graded material tubes made of SiC-SiC_f with a SiC polycrystalline sealing coating and chemically vapour infiltrated (CVI) SiC_f/SiC composite discs have been tested.The permeation tests have been aimed at verifying the effectiveness of coatings obtained by chemical vapour deposition (CVD) and used for closing the porosity of the composite materials and assuring their gas sealing. The measurements have been carried out at room temperature with operating pressure in the range 130-500 kPa. The SiC-SiC_f/SiC functionally graded material has shown very low permeability values. The CVI SiC_f/SiC composite tested has shown rather low permeance values, although the material is not gas tight: its reduced permeance was attributed to both the high fibre percentage and the dense SiC coating.     

Mechanistic kinetic model of an epoxy resin cured with a mixture of amines of different functionalities

The polymerization kinetics of a monoamine (p-toluidine), a diamine (4,4′-diaminodiphenylmethane) or a mixture of both amines reacted with an epoxy prepolymer, diglycidylether of bisphenol A (DGEBA), was analyzed using differential scanning calorimetry. A simple mechanistic model, consisting of an epoxy-hydroxyl complex formation out of equilibrium, including the possibility that amino hydrogens react with free epoxy groups or with the epoxy-hydroxyl complex, and taking into account the possible difference of the reactivity of amino hydrogens, provided a reasonable fitting of the whole set of experimental results with a lonely set of activation energies.     

Flavanones in Citrus fruit: Structure–antioxidant activity relationships

Epidemiological surveys have shown an inverse relationship between the intake of fruit and the incidence of coronary heart disease and some type of cancer. Data found in the literature regarding the flavonoids in general while this study focuses on flavanones, a subclass of flavonoids which occurs in Citrus fruit. The aim of this work is to elucidate the antioxidant or pro-oxidant behaviours of some common flavanones and to determine their activity–structure relationships as antioxidant using the crocin bleaching inhibition assay. The compounds studied were regarding both the aglycon form and the glycoside form. Data evidence that the substitution of the 7th OH group of the flavanones by a neohesperidoside influences the relationship between structure and antioxidant activity. In fact, the 3′,4′-catechol structure and the O-methylation, in the aglycone forms, do not result significant. On the other hands, in the glycosylate forms, the 3′,4′-catechol structure noticeably increases the antioxidant power and the O-methylation decreases the antioxidant activity. The influence of the O-glycosylation with a rutinose molecule is neglectable.     

The MTCY428.08 gene of Mycobacterium tuberculosis codes for NAD+ synthetase

The product of the MTCY428.08 gene of Mycobacterium tuberculosis shows sequence homology with several NAD+ synthetases. The MTCY428.08 gene was cloned into the expression vectors pGEX-4T-1 and pET-15b. Expression in Escherichia coli led to overproduction of glutathione S-transferase fused and His6-tagged gene products, which were enzymatically assayed for NAD synthetase activity. Our results demonstrate that the MTCY428.08 gene of M. tuberculosis is the structural gene for NAD+ synthetase.     

Protective Effect of Tyrosol and S-Adenosylmethionine against Ethanol-Induced Oxidative Stress of Hepg2 Cells Involves Sirtuin 1, P53 and Erk1/2 Signaling

Oxidative stress plays a major role in ethanol-induced liver damage, and agents with antioxidant properties are promising as therapeutic opportunities in alcoholic liver disease. In the present work, we investigated the effect of S-adenosylmethionine (AdoMet), Tyrosol (Tyr), and their combination on HepG2 cells exposed to ethanol exploring the potential molecular mechanisms. We exposed HepG2 cells to 1 M ethanol for 4 and 48 h; thereafter, we recorded a decreased cell viability, increase of intracellular reactive oxygen species (ROS) and lipid accumulation, and the release into culture medium of markers of liver disease such as triacylglycerol, cholesterol, transaminases, albumin, ferritin, and homocysteine. On the other hand, AdoMet and Tyrosol were able to attenuate or antagonize these adverse changes induced by acute exposure to ethanol. The protective effects were paralleled by increased Sirtuin 1 protein expression and nuclear translocation and increased ERK1/2 phosphorylation that were both responsible for the protection of cells from apoptosis. Moreover, AdoMet increased p53 and p21 expression, while Tyrosol reduced p21 expression and enhanced the expression of uncleaved caspase 3 and 9, suggesting that its protective effect may be related to the inhibition of the apoptotic machinery. Altogether, our data show that AdoMet and Tyrosol exert beneficial effects in ethanol-induced oxidative stress in HepG2 cells and provide a rationale for their potential use in combination in the prevention of ethanol-induced liver damage.     

Infrared‐Emitting QDs for Thermal Therapy with Real‐Time Subcutaneous Temperature Feedback

Nowadays, one of the most exciting applications of nanotechnology in biomedicine is the development of localized, noninvasive therapies for diverse diseases, such as cancer. Among them, nanoparticle‐based photothermal therapy (PTT), which destroys malignant cells by delivering heat upon optical excitation of nanoprobes injected into a living specimen, is emerging with great potential. Two main milestones that must be reached for PTT to become a viable clinical treatment are deep penetration of the triggering optical excitation and real‐time accurate temperature monitoring of the ongoing therapy, which constitutes a critical factor to minimize collateral damage. In this work, a yet unexplored capability of near‐infrared emitting semiconductor nanocrystals (quantum dots, QDs) is demonstrated. Temperature self‐monitored ­QD‐based PTT is presented for the first time using PbS/CdS/ZnS QDs emitting in the second biological window. These QDs are capable of acting, simultaneously, as photothermal agents (heaters) and high‐resolution fluorescent thermal sensors, making it possible to achieve full control over the intratumoral temperature increment during PTT. The differences observed between intratumoral and surface temperatures in this comprehensive investigation, through different irradiation conditions, highlight the need for real‐time control of the intratumoral temperature that allows for a dynamic adjustment of the treatment conditions in order to maximize the efficacy of the therapy.