Hotspots identification and ranking for road safety improvement: An alternative approach

During the last decade, the concept of composite performance index, brought from economic and business statistics, has become a popular practice in the field of road safety, namely for the identification and classification of worst performing areas or time slots also known as hotspots. The overall quality of a composite index depends upon the complexity of phenomena of interest as well as the relevance of the methodological approach used to aggregate the various indicators into a single composite index. However, current aggregation methods used to estimate the composite road safety performance index suffer from various deficiencies at both the theoretical and operational level; these include the correlation and compensability between indicators, the weighting of the indicators as well as their high “degree of freedom” which enables one to readily manipulate them to produce desired outcomes (0060, 0065 and 0070). The objective of this study is to contribute to the ongoing research effort on the estimation of road safety composite index for hotspots’ identification and ranking. The aggregation method for constructing the composite road safety performance index introduced in this paper, strives to minimize the aforementioned deficiencies of the current approaches. Furthermore, this new method can be viewed as an intelligent decision support system for road safety performance evaluation, in order to prioritize interventions for road safety improvement.     

A Heat Conductor with Fading Memory: Dissipation and Free Energies

Some expressions for the free energies of differential systems connected with a rigid heat conductor with memory are studied. The properties of these materials are given by a dynamical system, where the state is expressed in terms of the past histories of the temperature and of its gradient. Finally, the internal dissipations, corresponding to each of these free energies, are also evaluated.     

Oleuropein and hydroxytyrosol inhibit MCF‐7 breast cancer cell proliferation interfering with ERK1/2 activation

The growth of many breast tumors is stimulated by estradiol (E2), which activates a classic mechanism of regulation of gene expression and signal transduction pathways inducing cell proliferation. Polyphenols of natural origin with chemical similarity to estrogen have been shown to interfere with tumor cell proliferation. The aim of this study was to investigate whether hydroxytyrosol (HT) and oleuropein (OL), two polyphenols contained in extra‐virgin olive oil, can affect breast cancer cell proliferation interfering with E2‐induced molecular mechanisms. Both HT and OL inhibited proliferation of MCF‐7 breast cancer cells. Luciferase gene reporter experiments, using a construct containing estrogen responsive elements able to bind estrogen receptor alpha (ERα) and the study of the effects of HT or OL on ERα expression, demonstrated that HT and OL are not involved in ERα‐mediated regulation of gene expression. However, further experiments pointed out that both OL and HT determined a clear inhibition of E2‐dependent activation of extracellular regulated kinase1/2 belonging to the mitogen activating protein kinase family. Our study demonstrated that HT and OL can have a chemo‐preventive role in breast cancer cell proliferation through the inhibition of estrogen‐dependent rapid signals involved in uncontrolled tumor cell growth.     

Rediscovering Hydrogel-Based Double-Diffusion Systems for Studying Biomineralization

For those seeking to model biomineralization in vitro, hydrogels can serve as excellent models of the extracellular matrix (ECM) microenvironment. A major challenge posed in implementing such systems is the logistics involved, from fundamental engineering to experimental design. For the study of calcium phosphate (e.g., hydroxyapatite) formation, many researchers use hydrogel-based double-diffusion systems (DDSs). The various designs of these DDSs are seemingly as unique as their applications. In this Highlight, we present a survey of four distinct types of double-diffusion systems and evaluate them in the context of fundamental diffusion theory. Based upon this analysis, we present the design and evaluation of an optimized system. The techniques and framework for the evaluation and construction of a DDS presented here can be applied to any DDS that a researcher may want to implement for their particular studies of biomineralization.     

High Molecular Size Humic Substances Enhance Phenylpropanoid Metabolism in Maize (<Emphasis Type="Italic">Zea mays</Emphasis> L.)

A high molecular weight humic fraction (>3,500 Da) was characterized chemically by DRIFT and ¹H NMR spectroscopy, and was applied to Zea mays L. plants to evaluate its effect on phenylpropanoid metabolism. The activity and gene expression of phenylalanine (tyrosine) ammonia-lyase (PAL/TAL), and the concentrations of phenolics and their amino acid precursors phenylalanine and tyrosine were assayed. Maximum induction of PAL/TAL activity and expression was obtained when the concentration of added humic substance was 1 mg C/l hydroponic solution. Phenylalanine and tyrosine significantly decreased (−16% and −22%, respectively), and phenolic compounds increased in treated plants. The effects of the humic substance could be ascribed partly to indoleacetic acid (27 nmol/mg C) in the humic fraction. Our results suggest that this humic fraction induces changes in phenylpropanoid metabolism. This is the first study that shows a relationship between humic substances and the phenylpropanoid pathway.     

Thermal and Nutritional Modulation of Sleep in Infant Rats.

Infant rats cycle rapidly between periods of high muscle tone (indicative of wakefulness) and periods of atonia (indicative of sleep). Here, the influence of air temperature on sleep in 8-day-old rats was examined by testing pups at thermoneutrality (35°C) and during moderate (28°C) and extreme (20°C) cold challenge; also, pups were tested 1, 4, and 8 hr after infusion of milk to assess the effects of food deprivation on sleep. Whereas moderate cooling slightly reduced sleep durations and altered the temporal patterning of myoclonic twitching, extreme cooling substantially decreased sleep durations and inhibited twitching. In contrast, food deprivation had little effect. Therefore, thermoregulatory mechanisms engaged during moderate cooling sustain sleep, whereas extreme cooling overwhelms these mechanisms, thereby promoting arousal. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dietary Soy Supplements Produce Opposite Effects on Anxiety in Intact Male and Female Rats in the Elevated Plus-Maze.

The effects of 2 popular, commercially available soy phytoestrogen supplements on anxiety in male, diestrus female, and proestrus female rats were examined with an elevated plus-maze. Both of the soy supplements were anxiolytic in proestrus females but anxiogenic in males as determined by time spent in the open arms. No effect of diet was seen in the diestrus females. The observed changes in anxiety were not because of altered levels of gonadal hormones, as serum estrogen and progesterone levels were unaffected by diet in the females. The results suggest that the soy supplements have sex- and cycle-specific effects on anxiety. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Shaping the Polypropionate Biosynthesis in the Solar‐Powered Mollusc Elysia viridis

Polypropionates that incorporate pyrones are a family of polyketides featuring the chemistry of a few marine molluscs capable of phototrophic CO₂ fixation as a result of storing viable symbiotic chloroplasts in their bodies. The role and origin of these molecules is poorly investigated, although the unusual biological activities and chemistry of these natural products have recently received renewed interest. Here, we report the results of in vivo studies on production of γ‐pyrone‐containing polypropionates in the Mediterranean mollusc Elysia viridis. Biosynthesis of the metabolites in the sacoglossan is shown to proceed through condensation of eight intact C₃ units by polyketide synthase assembly. LC–MS and NMR spectroscopic studies demonstrate that the process involves a pyrone tetraene ( 10 ) as key intermediate, whereas the levels of the final polypropionates ( 6 , 7 and 9 ) are related to each other and show a significant dependence upon light conditions.     

Stable Alignment of Tautomers at Room Temperature in Porphyrin 2D Layers

A major challenge in molecular electronics is to develop logic devices based on a truly intramolecular switching mechanism. Recently, a new type of molecular device has been proposed where the switching characteristic is mediated by the bistability in the position of the two hydrogen atoms which can occupy different, energetically equivalent positions (tautomerization) in the inner cavity of porphyrins and naphthalocyanines. Up to now, such a reaction has only been exploited at low temperatures and induced or detected through atomic scale manipulation. In addition, the unpredictability of the tautomer orientation currently excludes molecular interconnection to functional electronic circuits. Here, full evidence is provided that, following a newly proposed growth strategy, 2D layers of metal‐free tetraphenylporphyrins (H₂TPP) show frozen tautomerization even at room temperature on macroscopic domains, with the H atoms aligned along a direction settled a priori. This behavior is ascribed to the buckling of the molecule, anchored to the substrate, which removes the degeneracy between the two tautomer alignments. On this basis, a new way to exploit uniaxially oriented H₂TPP tautomers in a first elementary logic device is proposed.     

Metal/polymer/metal hybrid systems: Towards potential formability applications

This paper deals with the development, forming and testing of functional three-layered metal/polymer/metal sandwich sheets – e.g. for automotive applications – in order to tailor them with particularly demanded properties.