bluuebunny/crossref_metadata_2025_split huggingface dataset:
Explaining the effect of a 1-year intervention promoting physical activity in middle schools: a mediation analysis
Authors: Haerens L , Cerin E , Maes L , Cardon G , Deforche B , De Bourdeaudhuij I 
Published: September 2007

AbstractObjectiveThe aim of the present study was to examine the mediation effects of changes in psychosocial determinants of physical activity (attitude, social support, self-efficacy, perceived benefits and barriers) on changes in physical activity.DesignOne-year intervention study with baseline and 1-year post measures of physical activity habits and psychosocial correlates.SettingFifteen middle schools.SubjectsBoys and girls (n = 2840) aged 11–15 years completed the validated questionnaires during class hours.ResultsThe product-of-coefficients test was used to asses the mediating effects. Self-efficacy for physical activity at school was found to be the only significant mediator of physical activity change. Specifically, self-efficacy for physical activity at school partly mediated the effect of the intervention on total and school-related physical activity change in the intervention group with parental support (P < 0.05). None of the other potential mediators, attitudes, social support, perceived benefits and perceived barriers, seemed to have had a positive effect. Even a suppressor effect was found for attitudes. Given that the effects of self-efficacy and attitudes were of opposite direction, the total mediated/suppressed effects of the intervention were not statistically significant.ConclusionsPositive changes in total and school-related physical activity in adolescents could be partly explained by increases in self-efficacy for physical activity at school through a physical activity intervention in middle schools with parental support. However, the suppressor effect of attitudes decreased this effect. As this is one of the first true mediation analyses in this age group, further research is needed to replicate the importance of these mediators.
Effects of ciprofloxacin on salt marsh sediment microbial communities
Authors: Córdova-Kreylos Ana Lucía , Scow Kate M 
Published: September 2007

Abstract
Fluoroquinolones, a widely used class of antibiotics, are frequently detected in sediments and surface waters. Given their antimicrobial properties, the presence of these compounds may alter the composition of microbial communities and promote antibiotic resistance in the environment. The purpose of this study was to measure sorption, and effects of ciprofloxacin on microbial community composition, in sediment samples from three California salt marshes. Sediments were exposed to a ciprofloxacin concentration gradient (0–200 μg ml−1 ciprofloxacin) and microbial community composition characterized using phospholipid fatty acid (PLFA) analysis. Sorption coefficients, expressed as log Kd, were calculated from fits using the Freundlich isotherm model. Ciprofloxacin strongly sorbed to all sediments and had log Kd values, ranging from 2.9 to 4.3. Clay content was positively (r2=0.98) and pH negatively (r2=0.99) correlated to Kd values. Biomass, PLFA richness, sulfate reducer and Gram-negative bacteria markers increased with ciprofloxacin concentrations, while the 17 cy/precursor and saturated/unsaturated biomarker ratios, indicators of starvation stress, decreased. The magnitude of the effect of ciprofloxacin on microbial communities was inversely correlated to the degree of sorption to the sediments. Despite the fact that ciprofloxacin is a wide-spectrum antibiotic, its impact on sediment microbial communities was selective and appeared to favor sulfate-reducing bacteria and Gram-negative bacteria.
Supraspinal modulation of pain by cannabinoids: the role of GABA and glutamate
Authors: Rea K , Roche M , Finn D P 
Published: September 2007

Recent physiological, pharmacological and anatomical studies provide evidence that one of the main roles of the endocannabinoid system in the brain is the regulation of γ‐aminobutyric acid (GABA) and glutamate release. This article aims to review this evidence in the context of its implications for pain. We first provide a brief overview of supraspinal regulation of nociception, followed by a review of the evidence that the brain's endocannabinoid system modulates nociception. We look in detail at regulation of supraspinal GABAergic and glutamatergic neurons by the endocannabinoid system and by exogenously administered cannabinoids. Finally, we review the evidence that cannabinoid‐mediated modulation of pain involves modulation of GABAergic and glutamatergic neurotransmission in key brain regions.British Journal of Pharmacology(2007)152, 633–648; doi:10.1038/sj.bjp.0707440; published online 10 September 2007
Alzheimer's disease; taking the edge off with cannabinoids?
Authors: Campbell V A , Gowran A 
Published: September 2007

Alzheimer's disease is an age‐related neurodegenerative condition associated with cognitive decline. The pathological hallmarks of the disease are the deposition of β‐amyloid protein and hyperphosphorylation of tau, which evoke neuronal cell death and impair inter‐neuronal communication. The disease is also associated with neuroinflammation, excitotoxicity and oxidative stress. In recent years the proclivity of cannabinoids to exert a neuroprotective influence has received substantial interest as a means to mitigate the symptoms of neurodegenerative conditions. In brains obtained from Alzheimer's patients alterations in components of the cannabinoid system have been reported, suggesting that the cannabinoid system either contributes to, or is altered by, the pathophysiology of the disease. Certain cannabinoids can protect neurons from the deleterious effects of β‐amyloid and are capable of reducing tau phosphorylation. The propensity of cannabinoids to reduce β‐amyloid‐evoked oxidative stress and neurodegeneration, whilst stimulating neurotrophin expression neurogenesis, are interesting properties that may be beneficial in the treatment of Alzheimer's disease. Δ9‐tetrahydrocannabinol can also inhibit acetylcholinesterase activity and limit amyloidogenesis which may improve cholinergic transmission and delay disease progression. Targeting cannabinoid receptors on microglia may reduce the neuroinflammation that is a feature of Alzheimer's disease, without causing psychoactive effects. Thus, cannabinoids offer a multi‐faceted approach for the treatment of Alzheimer's disease by providing neuroprotection and reducing neuroinflammation, whilst simultaneously supporting the brain's intrinsic repair mechanisms by augmenting neurotrophin expression and enhancing neurogenesis. The evidence supporting a potential role for the cannabinoid system as a therapeutic target for the treatment of Alzheimer's disease will be reviewed herewith.British Journal of Pharmacology (2007) 152, 655–662; doi:10.1038/sj.bjp.0707446; published online 10 September 2007
Δ9‐Tetrahydrocannabinol inhibits electrically‐evoked CGRP release and capsaicin‐sensitive sensory neurogenic vasodilatation in the rat mesenteric arterial bed
Authors: Wilkinson J D , Kendall D A , Ralevic V 
Published: September 2007

Background and purpose:Calcitonin gene‐related peptide (CGRP) is a sensory neurotransmitter in the rat mesenteric arterial bed. Certain cannabinoids can inhibit, via CB1 receptors, vasorelaxant responses to electrical field stimulation (EFS) of sensory nerves in the rat mesentery, but the mechanism of the inhibitory effect of the cannabinoid Δ9‐tetrahydrocannabinol (THC) is unclear. This study assessed directly the effect of THC on EFS‐induced release of CGRP from sensory nerves in the rat mesenteric bed and investigated the possible involvement of cannabinoid receptors and transient receptor potential (TRP) ion channels.Experimental approach:Rat mesenteric beds were perfused with physiological salt solution. Sensory nerves were stimulated electrically and perfusate levels of CGRP measured by immunoassay. The effects of THC on EFS‐induced CGRP release and vasorelaxant responses to sensory nerve stimulation were investigated in the absence and presence of cannabinoid antagonists and TRP channel blockers.Key results:EFS evoked a release of CGRP and vasodilatation of the mesenteric beds. THC inhibited the electrically‐evoked release of CGRP and sensory neurogenic vasorelaxation. The effect of THC was unaffected by the CB1 antagonist AM251, the CB2 antagonist AM630 or the TRPV1 receptor antagonist capsazepine, but was blocked by the TRP channel blocker ruthenium red.Conclusions and implications:THC inhibits the EFS‐induced release of CGRP (and subsequent vasorelaxation), from capsaicin‐sensitive sensory nerves in the rat perfused mesentery. The effect of THC was not mediated by CB1, CB2 or TRPV1 receptors, but was sensitive to ruthenium red, suggesting a possible involvement of TRP ion channels.British Journal of Pharmacology (2007) 152, 709–716; doi:10.1038/sj.bjp.0707448; published online 10 September 2007
Reduced inhibition of cortical glutamate and GABA release by halothane in mice lacking the K+ channel, TREK‐1
Authors: Westphalen R I , Krivitski M , Amarosa A , Guy N , Hemmings H C 
Published: September 2007

Background and purpose:Deletion of TREK‐1, a two‐pore domain K+ channel (K2P) activated by volatile anaesthetics, reduces volatile anaesthetic potency in mice, consistent with a role for TREK‐1 as an anaesthetic target. We used TREK‐1 knockout mice to examine the presynaptic function of TREK‐1 in transmitter release and its role in the selective inhibition of glutamate vs GABA release by volatile anaesthetics.Experimental approach:The effects of halothane on 4‐aminopyridine‐evoked and basal [3H]glutamate and [14C]GABA release from cerebrocortical nerve terminals isolated from TREK‐1 knockout (KO) and littermate wild‐type (WT) mice were compared. TREK‐1 was quantified by immunoblotting of nerve terminal preparations.Key results:Deletion of TREK‐1 significantly reduced the potency of halothane inhibition of 4‐aminopyridine‐evoked release of both glutamate and GABA without affecting control evoked release or the selective inhibition of glutamate vs GABA release. TREK‐1 deletion also reduced halothane inhibition of basal glutamate release, but did not affect basal GABA release.Conclusions and implications:The reduced sensitivity of glutamate and GABA release to inhibition by halothane in TREK‐1 KO nerve terminals correlates with the reduced anaesthetic potency of halothane in TREK‐1 KO mice observed in vivo. A presynaptic role for TREK‐1 was supported by the enrichment of TREK‐1 in isolated nerve terminals determined by immunoblotting. This study represents the first evidence for a link between an anaesthetic‐sensitive 2‐pore domain K+ channel and presynaptic function, and provides further support for presynaptic mechanisms in determining volatile anaesthetic action.British Journal of Pharmacology (2007) 152, 939–945; doi:10.1038/sj.bjp.0707450; published online 10 September 2007
On the theoretical implications of Cypriot Greek initial geminates
Authors: Muller Jennifer S. 
Published: September 2007

AbstractCypriot Greek contrasts singleton and geminate consonants in word-initial position. These segments are of particular interest to phonologists since two divergent representational frameworks, moraic theory (Hayes 1989) and timing-based frameworks, including CV or X-slot theory (Clements and Keyser 1983, Levin 1985), account for the behavior of initial geminates in substantially different ways. The investigation of geminates in Cypriot Greek allows these differences to be explored. As will be demonstrated in a formal analysis of the facts, the patterning of geminates in Cypriot is best accounted for by assuming that the segments are dominated by abstract timing units such as X- or C-slots, rather than by a unit of prosodic weight such as the mora.
Déplacement et repositionnement de la préposition à en français
Authors: Goyens Michèle , Lamiroy Béatrice , Melis Ludo 
Published: September 2007

In Modern French, the preposition à has a large number of uses, in contrast to the Latin prepositions ad, ab and apud from which it derives. They can be classified into seven groups: complements expressing (1) place (where?), (2) time (when?), (3) manner, cause or instrument (how?); non locative complements commutating with (5) y or (6) lui, and finally (7) complements expressing possession. This evolution has been described lately as a result of a grammaticalization process, whereby the non locative uses emerged from the locative meaning by an increasing degree of abstraction.

First, we show how a comparison with synchronic Romance data (Italian and Spanish), and with diachronic data from Old French, allows us to refine the description of the overall grammaticalization process which involves French à. Moreover, we analyze less well known empirical data concerning lexical and morphosyntactic restrictions on present-day uses of French à. Both kinds of data account for our hypothesis : we argue in particular that the preposition’s main function is no longer that of expressing locative meaning (or adverbial meaning in general) but its use as a mere syntactic complementizer.
Furthermore, we show that the preposition is subject not only to a grammaticalization process, but also to a lexicalization process. That the latter also mainly holds for the adverbial uses of à provides evidence for the same hypothesis, viz. the core uses of Modern French à can be described as the result of a ‘repositioning’ of the preposition from the adverbial domain into the structural domain of the indirect object.
Role of intensively managed forests in future timber supply.
Authors: Cown D. J. 
Published: September 2007

Abstract
Much is reported about the destruction of natural forests and the consequences for global warming, while on the other hand, exotic plantations in some regions struggle to gain public acceptance. The earth's population is projected to rise to around 9 billion by 2050, with a concomitant increase in demand for forest products. Inevitably, forests in general, and managed forest in particular, will be called on to provide an ever-increasing proportion of local supplies and the international wood trade. Five countries - China, USA, Russian Federation, India and Japan - have each established more than 10 million ha of plantation forests, collectively accounting for 65% of the global plantation resource. Forest managers have made huge strides over the past 200 years or so in improving crops through the application of silviculture and genetics. Yields and quality have been greatly increased in managed forests and exotic plantations by spacing and pruning regimes that allow shorter rotations and improved quality. A common issue is now the higher proportion of juvenile wood produced in these situations, but technologies such as material segregation and recombination are reducing the impact on customers. A major emerging factor is the growing awareness of the significant contribution of forests to global warming by decision-makers, and pressure of commitments to international agreements, such as the Kyoto Protocol. This could lead to governments around the world creating and introducing a more favourable business climate for forestry activities, and a very significant increase in the proportion of global wood products derived from managed forests. However, the wood products industries cannot be complacent, as each generation brings new breeds of end users with less sentimental attachment with wood.
Bovine colostrum nutrient composition.
Authors: Kehoe S. I. , Heinrichs A. J. 
Published: September 2007

Abstract

The physiology of the ruminant placenta inhibits the transfer of large-molecular-weight structures
in utero
, thus making it essential that newborn calves receive a substantial amount of colostrum. Ruminant neonates must ingest colostrum for many reasons; however, attaining passive transfer of immunity from the dam is essential. Colostrum also contains other components that are important in satisfying nutritional requirements; high levels of fat, protein, vitamins, and minerals enable neonatal calves to begin building muscle, storing fat and initiating metabolic activities. Colostrum also provides high levels of growth factors and nucleotides, which have been reported to improve the maturation of intestinal tissue in growing neonates. Although average colostrum provides higher concentrations of nutrients compared with mature milk, there are differences among breeds of cows as well as parities that result in differing colostrum quality. For example, Holsteins produce colostrum that contains lower immunoglobulin concentrations when compared with other breeds. Also, younger parities produce colostrum with lower immunoglobulin concentrations compared with older cattle. Researchers have attempted to manipulate colostrum components through nutrition but have thus far only been successful in increasing certain vitamin and mineral concentrations. Continued research needs to evaluate whether other nutritional components of colostrum can be increased to improve neonatal survivability.
Animal health economics  where have we come from and where do we go next?
Authors: Rushton J. , Viscarra R. , Otte J. , McLeod A. , Taylor N. 
Published: September 2007

Abstract
The early initiatives on animal disease control measures were stimulated and justified by unacceptable losses of animals from rinderpest and foot and mouth disease (FMD) in Europe in the nineteenth century. In the 1960s, an increasingly large and ambitious veterinary profession turned to cost-benefit analysis methods in order to justify previous and proposed animal disease campaigns that supported livestock producers using more intensive production systems. These economic assessment methods were in the process of being developed and refined, and were increasingly important in the assessment of public investments. Some economists saw the use of cost-benefit analysis as simply an add-on to the technical aspects of animal disease control, and requested more rigorous economics when looking at the subject of animal health. This was the beginning of an ongoing debate on animal health economics that has developed into a number of different strands of thought. The paper reviews the development of animal health economics and the question whether there are new issues and opportunities that the subject needs to address. In this way it provides information on where animal health economics has come from and where it should be going next.
Metabolic engineering of carotenoid levels for improvement of plants as food.
Authors: Diretto G. , Fiore A. , Giuliano G. 
Published: September 2007

Abstract
Carotenoids are ubiquitous isoprenoid pigments that are synthesized by archaea, bacteria, fungi, algae and higher plants: in these organisms, they have fundamental ecological, biochemical and physiological functions. Carotenoids also play a crucial role in human health by improving normal vision and by preventing degenerative diseases and cancer. Mammals do not produce carotenoids and therefore need to assume them through the diet. Most major crops (including rice, wheat and potato) contain little α- and β-carotene, which are the main carotenoids with provitamin A activity. For this reason, during the last 10 years, increasing carotenoid (especially β-carotene) levels in major crops through genetic transformation has been one of the main goals of plant metabolic engineering. This review will focus on past and recent advances in this field, with particular attention to the modification of carotenoid biosynthesis in rice, tomato and potato. 'Golden Rice' is probably the most widely known result of metabolic engineering; in tomato, expression of carotenoid genes, both of bacterial and plant origin, resulted in an increase of β-carotene and/or total xanthophylls in transgenic fruits. In the past 3 years several metabolic engineering efforts have also focused on potato, resulting in the obtainment of 'golden tubers', with the highest β-carotene content reported for the four major crops.
Using genetics to improve stress resistance through altering root architecture.
Authors: Pićo B. , Fita A. , Nuez F. 
Published: September 2007

Abstract

Root architecture is a key feature of roots that contributes to improving plant performance under stress. Identifying relevant root traits and defining their role in resistance to the different stresses is not an easy task. In this review, we describe the difficulties associated with the study of roots, which are mainly derived from their underground nature and high phenotypic plasticity. The evolution of the methods used for root analysis is reviewed with special attention to those that allow an accurate monitoring of the growth of whole root systems in space and time. The role of root modelling in assisting the study of root morphology and function is highlighted. Understanding the genetics of root formation is essential to exploiting root architecture in breeding programmes. Here, we summarize the information about natural and artificial variations in root architecture reported to date in the model species
Arabidopsis thaliana
and in economically relevant species: mostly cereals and legumes. In addition to the classical genetics studies, we report how new biotechnologies are contributing to increasing our understanding of root genetics. We discuss progress made using mutant screening and other genomic tools towards identifying genes involved in root development. In addition, progress made with the identification of quantitative trait loci responsible for natural variation in root architectural traits is summarized here; with an emphasis on their use in marker-assisted programmes aimed at producing cultivars with altered root architecture and increased resistance to stress.
A syntactic model to design and verify synthetic genetic constructs derived from standard biological parts
Authors: Cai Yizhi , Hartnett Brian , Gustafsson Claes , Peccoud Jean 
Published: September 2007

AbstractMotivation: The sequence of artificial genetic constructs is composed of multiple functional fragments, or genetic parts, involved in different molecular steps of gene expression mechanisms. Biologists have deciphered structural rules that the design of genetic constructs needs to follow in order to ensure a successful completion of the gene expression process, but these rules have not been formalized, making it challenging for non-specialists to benefit from the recent progress in gene synthesis.Results: We show that context-free grammars (CFG) can formalize these design principles. This approach provides a path to organizing libraries of genetic parts according to their biological functions, which correspond to the syntactic categories of the CFG. It also provides a framework for the systematic design of new genetic constructs consistent with the design principles expressed in the CFG. Using parsing algorithms, this syntactic model enables the verification of existing constructs. We illustrate these possibilities by describing a CFG that generates the most common architectures of genetic constructs in Escherichia coli.Availability: A web site allows readers to experiment with the algorithms presented in this article: www.genocad.orgContact: peccoud@vt.eduSupplementary information: Sequences and models are available at Bioinformatics online.