bluuebunny/crossref_metadata_2025 huggingface dataset:
Muscle architecture and functional anatomy of the pelvic limb of the ostrich (Struthio camelus)
Authors: Smith N. C. , Wilson A. M. , Jespers K. J. , Payne R. C.
Published: November 2006

The functional anatomy of the pelvic limb of the ostrich (Struthio camelus) was investigated in order to assess musculoskeletal specialization related to locomotor performance. The pelvic limbs of ten ostriches were dissected and detailed measurements of all muscle tendon units of the pelvic limb were made, including muscle mass, muscle length, fascicle length, pennation angle, tendon mass and tendon length. From these measurements other muscle properties such as muscle volume, physiological cross‐sectional area (PCSA), tendon cross‐sectional area, maximum isometric muscle force and tendon stress were derived, using standard relationships and published muscle data. Larger muscles tended to be located more proximally and had longer fascicle lengths and lower pennation angles. This led to an expected proximal to distal reduction in total muscle mass. An exception to this trend was the gastrocnemius muscle, which was found to have the largest volume and PCSA and also had the highest capacity for both force and power production. Generally high‐power muscles were located more proximally in the limb, while some small distal muscles (tibialis cranialis and flexor perforatus digiti III), with short fibres, were found to have very high force generation capacities. The greatest proportion of pelvic muscle volume was for the hip extensors, while the highest capacity for force generation was observed in the extensors of the ankle, many of which were also in series with long tendons and thus were functionally suited to elastic energy storage.
GABAA receptor associated proteins: a key factor regulating GABAA receptor function
Authors: Chen Zi‐Wei , Olsen Richard W.
Published: November 2006

γ‐Aminobutyric acid (GABA), an important inhibitory neurotransmitter in both vertebrates and invertebrates, acts on GABA receptors that are ubiquitously expressed in the CNS. GABAA receptors also represent a major site of action of clinically relevant drugs, such as benzodiazepines, barbiturates, ethanol, and general anesthetics. It has been shown that the intracellular M3‐M4 loop of GABAA receptors plays an important role in regulating GABAA receptor function. Therefore, studies of the function of receptor intracellular loop associated proteins become important for understanding mechanisms of regulating receptor activity. Recently, several labs have used the yeast two‐hybrid assay to identify proteins interacting with GABAA receptors, for example, the interaction of GABAA receptor associated protein (GABARAP) and Golgi‐specific DHHC zinc finger protein (GODZ) with γ subunits, PRIP, phospholipase C‐related, catalytically inactive proteins (PRIP‐1) and (PRIP‐2) with GABARAP and receptor γ2 and β subunits, Plic‐1 with some α and β subunits, radixin with the α5 subunit, HAP1 with the β1 subunit, GABAA receptor interacting factor‐1 (GRIF‐1) with the β2 subunit, and brefeldin A‐inhibited GDP/GTP exchange factor 2 (BIG2) with the β3 subunit. These proteins have been shown to play important roles in modulating the activities of GABAA receptors ranging from enhancing trafficking, to stabilizing surface and internalized receptors, to regulating modification of GABAA receptors. This article reviews the current studies of GABAA receptor intracellular loop‐associated proteins.
Somatostatin, a negative‐regulator of central leptin action in the rat hypothalamus
Authors: Stepanyan Z. , Kocharyan A. , Behrens M. , Koebnick C. , Pyrski M. , Meyerhof W.
Published: November 2006

Leptin‐responsive neurons of the hypothalamus constitute a heterogeneous population expressing a vast array of different neuropeptides and neurotransmitters, some of which participate in the regulation of hunger and satiety. Here we report that somatostatin modulates the efficacy of leptin‐signalling in the rat hypothalamus. Using a two‐pulse paradigm at 30‐min intervals, we delivered somatostatin or somatostatin receptor subtype‐selective agonists in combination with leptin into the lateral cerebral ventricle of stereotaxically cannulated rats. To monitor the effect of somatostatin on the leptin‐signalling pathway, we quantified changes in the leptin‐mediated activation of STAT3, the signal transducer and activator of transcription 3. Successive administration of somatostatin and leptin diminished the level of STAT3‐phosphorylation and nuclear STAT3 translocation in the ventromedial and dorsomedial hypothalamic nuclei, the lateral hypothalamic area, and the arcuate nucleus by about 40% compared to leptin administration alone. Furthermore, application of subtype‐selective somatostatin receptor agonists suggests that the observed reduction in leptin‐responsiveness is predominantly mediated by the sst3 receptor‐subtype, followed by sst1 and sst2. In addition, the intensity of the negative‐regulatory effect of somatostatin on leptin‐signalling displayed regional differences for the three receptor‐subtypes involved. Addressing the functional consequences of the diminished leptin‐signalling, behavioural analyses showed that centrally applied somatostatin counteracts the leptin‐mediated suppression of food intake. These results suggest that the pleiotropic effector somatostatin also plays a role in the central regulation of energy homeostasis.
Demographic Characteristics of Extinction in a Small, Insular Population of House Sparrows in Northern Norway
Authors: RINGSBY THOR HARALD , SÆTHER BERNT‐ERIK , JENSEN HENRIK , ENGEN STEINAR
Published: November 2006

Abstract:  In conservation ecology there is an urgent need for indicators that can be used to predict the risk of extinction of populations. Identifying extinction‐prone populations has been difficult because few data sets on the demographic characteristics of the final stage to extinction are available and because of problems in separating out stochastic effects from changes in the expected dynamics. We documented the demographic changes that occurred during the period prior to extinction of a small island population of House Sparrows (Passer domesticus) after the end of permanent human settlement. A mark‐recapture analysis revealed that this decline to extinction was mainly due to increased mortality after closure of the last farm that resulted in a negative long‐term‐specific growth rate. No change occurred in either the structural composition (breeding sex ratio and age distribution) of the population or in female recruitment. No male, however, recruits were produced on the island after the farm closure. Based on a simple, stochastic, density‐dependent model we constructed a population prediction interval (PPI) to estimate the time to extinction. The 95% PPI slightly overestimated the time to extinction with large uncertainty in predictions, especially due to the influence of demographic stochasticity and parameter drift. Our results strongly emphasize the importance of access to data on temporal variation that can be used to parameterize simple population models that allow estimation of critical parameters for credible prediction of time to extinction.
When Agendas Collide: Human Welfare and Biological Conservation
Authors: CHAN KAI M. A. , PRINGLE ROBERT M. , RANGANATHAN JAI , BOGGS CAROL L. , CHAN YVONNE L. , EHRLICH PAUL R. , HAFF PETER K. , HELLER NICOLE E. , AL‐KHAFAJI KARIM , MACMYNOWSKI DENA P.
Published: November 2006

Abstract:  Conservation should benefit ecosystems, nonhuman organisms, and current and future human beings. Nevertheless, tension among these goals engenders potential ethical conflicts: conservationists' true motivations may differ from the justifications they offer for their activities, and conservation projects have the potential to disempower and oppress people. We reviewed the promise and deficiencies of integrating social, economic, and biological concerns into conservation, focusing on research in ecosystem services and efforts in community‐based conservation. Despite much progress, neither paradigm provides a silver bullet for conservation's most pressing problems, and both require additional thought and modification to become maximally effective. We conclude that the following strategies are needed to make conservation more effective in our human‐dominated world. (1) Conservation research needs to integrate with social scholarship in a more sophisticated manner. (2) Conservation must be informed by a detailed understanding of the spatial, temporal, and social distributions of costs and benefits of conservation efforts. Strategies should reflect this understanding, particularly by equitably distributing conservation's costs. (3) We must better acknowledge the social concerns that accompany biodiversity conservation; accordingly, sometimes we must argue for conservation for biodiversity's sake, not for its direct human benefits.
Transferability of Species Distribution Models: a Functional Habitat Approach for Two Regionally Threatened Butterflies
Authors: VANREUSEL WOUTER , MAES DIRK , VAN DYCK HANS
Published: November 2006

Abstract: Numerous models for predicting species distribution have been developed for conservation purposes. Most of them make use of environmental data (e.g., climate, topography, land use) at a coarse grid resolution (often kilometres). Such approaches are useful for conservation policy issues including reserve‐network selection. The efficiency of predictive models for species distribution is usually tested on the area for which they were developed. Although highly interesting from the point of view of conservation efficiency, transferability of such models to independent areas is still under debate. We tested the transferability of habitat‐based predictive distribution models for two regionally threatened butterflies, the green hairstreak (Callophrys rubi) and the grayling (Hipparchia semele), within and among three nature reserves in northeastern Belgium. We built predictive models based on spatially detailed maps of area‐wide distribution and density of ecological resources. We used resources directly related to ecological functions (host plants, nectar sources, shelter, microclimate) rather than environmental surrogate variables. We obtained models that performed well with few resource variables. All models were transferable—although to different degrees—among the independent areas within the same broad geographical region. We argue that habitat models based on essential functional resources could transfer better in space than models that use indirect environmental variables. Because functional variables can easily be interpreted and even be directly affected by terrain managers, these models can be useful tools to guide species‐adapted reserve management.
Evidence that moment‐to‐moment variation in positive emotions buffer genetic risk for depression: a momentary assessment twin study
Authors: Wichers Marieke c. , Myin‐Germeys Inez , Jacobs Nele , Peeters Frenk , Kenis Gunter , Derom Catherine , Vlietinck Robert , Delespaul Philippe , Van Os Jim
Published: November 2006

Objective:  The negative affective response to daily life stressors, which previous work suggest is a fundamental depression endophenotype, may be moderated by positive emotions. It was investigated whether positive affect (PA) buffers negative affect (NA) reactivity in response to stress and whether PA moderates the genetic predisposition to negative affect reactivity.

Method:  A total of 279 twin pairs participated in a momentary assessment study with the experience sampling method, collecting appraisals of stress and affect in the flow of daily life. Lifetime diagnoses of depression were obtained.

Results:  There was a significant interaction between stress appraisal of event (STRESS) and PA in the association with NA. The interaction between proband PA, proband STRESS and co‐twin lifetime depression showed that higher PA reduced the interaction between proband STRESS and co‐twin lifetime depression.

Conclusion:  Positive emotions not only buffer against NA reactivity, but in addition attenuate genetic effects on negative mood bias in daily life.
Surgical Planning and Prosthesis Construction Using Computed Tomography, CAD/CAM Technology, and the Internet for Immediate Loading of Dental Implants
Authors: Balshi Stephen F. , Wolfinger Glenn J. , Balshi Thomas J.
Published: November 2006

This report describes a protocol that uses computer technology and medical imaging to virtually place anterior and posterior dental implants and to construct a precise surgical template and prosthesis, which is connected at the time of implant placement. This procedure drastically reduces patient office time, surgical treatment time, and the degree of post‐treatment recovery. Patients with an edentulous arch or a partially edentulous area had a denture with radiopaque markers constructed for computed tomography (CT) scans of the appropriate jaw. The CT images, having acquisition slices of 0.4 mm, are transposed in a three‐dimensional image‐based program for planning and strategic placement of dental implants. After virtual implant placement on the computer, the surgical treatment plan is sent to a manufacturing facility for construction of the surgical template. The manufactured surgical components and surgical template arrive on the clinical site. From the surgical template, the dental laboratory retro‐engineers the master cast, articulates it with the opposing dentition based on a duplicate of the scanning denture, and creates the prosthesis. Using the surgical template, minimally invasive surgery is performed without a flap, and the prosthesis is delivered, achieving immediate functional loading to the implants. Minor occlusal adjustments are made. The total surgical treatment time required is typically between 30 and 60 minutes. Postoperative symptoms such as pain, swelling, and inflammation are dramatically reduced.

CLINICAL SIGNIFICANCE

Identification of the bone in relationship to the tooth position via three‐dimensional CT prior to surgery allows the clinician to precisely place implants. Computer‐aided design/computer‐assisted manufacture technology using the three‐dimensional images allows for fabrication of the surgical template. This is a significant advancement in implant dentistry and promotes interdisciplinary approaches to patient treatment. The implant surgeon and restorative dentist can agree upon implant locations and screw access locations prior to the surgical episode.
Esthetic Potential of Single‐Implant Provisional Restorations: Selection Criteria of Available Alternatives
Authors: Priest George
Published: November 2006

Provisional implant restorations are essential tools used to optimize the esthetic outcomes for single‐tooth implant restorations. This article describes three groups of available alternatives and the specific options within each group including removable prostheses (interim removable partial denture, vacuum‐formed appliance), tooth‐supported prostheses (bonded extracted or denture teeth, cast metal or fiber‐reinforced resin‐bonded fixed partial denture [FPD], wire‐retained resin‐bonded FPD, acrylic resin provisional FPD), and implant‐supported fixed prostheses (implant‐retained provisional restoration). Advantages and disadvantages as well as fabrication guidelines for each option are provided. The author proposes that the restorative dentist consider eight criteria in selecting the most appropriate type of provisional prosthesis for a specific patient situation including the esthetic potential, patient comfort, treatment time, laboratory cost, occlusal clearance, ease of removal, durability, and ease of modification. The patient’s esthetic expectations are critical in determining the most suitable type of provisional restoration. Esthetically pleasing provisional restorations are part of the evolving implant continuum, making implant dentistry more appealing to practicing dentists and potential patients.

CLINICAL SIGNIFICANCE

Provisional restorations for single implants have evolved from temporary expedients during osseous and soft tissue integration to critical therapeutic tools used to assess patient expectations, communicate with the laboratory, and optimize definitive implant treatment. The selection of the type of provisional restoration may significantly influence esthetics during the period of implant integration and soft tissue healing. However, it is unlikely that there is a direct correlation between the type of provisional restoration used and the esthetic outcome of the definitive prosthesis.
Writing Revolution: British Literature and the French Revolution Crisis, a Review of Recent Scholarship1
Authors: Grenby M. O.
Published: November 2006

The French Revolution had a profound effect on almost all aspects of British culture. French events and ideas were avidly discussed and disputed in Britain. Long‐standing British political and cultural debates were given new life; new socio‐political ideologies rapidly emerged. The sense of political, religious and cultural crisis that developed in the 1790s was only slowly to dissipate. Generations afterwards, many British thinkers and writers were still considering and renegotiating their responses. The effect of the Revolution Crisis on British literature was particularly marked, something that was widely recognised at the time and has been the focus of much scholarship since. It has become something of a cliché that British literary Romanticism was born out of the Revolution. The last few decades have produced new waves of powerful criticism which has re‐examined the relationship between the Revolution Crisis and the works it shaped. Different strands of radical writing have now received detailed investigation, as have equally complex conservative responses. Writing by and for women is now receiving as much attention as writing by men, and previously neglected forms, such as the popular novel, pamphlets and children's literature, are now the subject of an increasing number of studies. The writing of the 1790s and early 1800s has in fact provided many scholars with their test‐case for exploring the very nature of the relationship between text and context. It is this profusion of recent, sophisticated and rapidly evolving scholarship which this article surveys.
‘[A] Place Among the Hindu Poets’: Orientalism and the Poetry of Sir William Jones (1746–1794)
Authors: Das Nandini
Published: November 2006

As a scholar, linguist and legal authority, Sir William Jones played a major role in shaping Europe's understanding of India and the Middle East, not only through his involvement in tasks such as the establishment of the Asiatic Society or the codification of Indian laws, but also through his own literary work. His writings on Persian and Indian literature have inspired a significant body of postcolonial critique, while their impact on poets such as Southey, Shelley, Byron and Coleridge has attracted the attention of scholars of Romantic literature. More importantly, however, scholars are now increasingly beginning to recognise the importance of Jones's work in illuminating a crucial stage of British colonial history, when the eighteenth‐century scholarly pursuit of ‘Oriental’ studies became increasingly embroiled in problematic negotiations with European imperialism. This article examines the role played by Jones's scholarship and poetry, particularly that produced during his tenure in India, in his efforts to mediate between two changing societies – India under British rule on the one hand, and the increasing professionalisation of knowledge in eighteenth‐century England on the other.
Do Ethical Consumers Care About Price? A Revealed Preference Analysis of Fair Trade Coffee Purchases
Authors: Arnot Chris , Boxall Peter C. , Cash Sean B.
Published: November 2006

The existing literature on socially responsible purchasing relies heavily on stated preference measures elicited through surveys that utilize hypothetical market choices. This paper explores consumers' revealed purchasing behavior with regard to fair trade coffee and is apparently the first to do so in an actual market setting. In a series of experiments, we investigated differences in consumer responsiveness to relative price changes in fair trade and non‐fair trade brewed coffees. In order to minimize the hypothetical bias that may be present in some experimental settings, we conducted our experiments in cooperation with a vendor who allowed us to vary prices in an actual coffee shop. Using a choice model, we found that purchasers of fair trade coffee were much less price responsive than those of other coffee products. The demonstration of low sensitivity to price suggests that the market premiums identified by stated preference studies do indeed exist and are not merely artifacts of hypothetical settings.

La littérature existante sur la consommation responsable repose fortement sur les mesures des préférences déclarées recueillies lors d'enquêtes utilisant des choix hypothétiques. Le présent article examine le comportement d'achat révélé des consommateurs concernant le cafééquitable et constitue apparemment le premier article du genre à le faire dans le contexte d'un marché réel. Au cours d'une série d'expériences, nous avons examiné les différentes réactions des consommateurs concernant les changements du prix relatif des cafés infusés équitables et classiques (non équitables). Pour minimiser le biais hypothétique qui pourrait exister dans certaines situations expérimentales, nous avons effectué nos expériences en collaboration avec un fournisseur qui nous a donné la permission de modifier les prix dans un véritable café‐restaurant. À l'aide d'un modèle de choix, nos résultats ont montré que les consommateurs de cafééquitable réagissaient beaucoup moins au prix que les consommateurs de café classique. Cette faible sensibilité au prix donne à penser que les primes de marché identifiées dans les études sur les préférences déclarées existent effectivement et qu'elles ne sont pas de simples phénomènes de situations hypothétiques.
Marketing Opportunities for Certified Pork Chops
Authors: Nilsson Tomas , Foster Ken , Lusk Jayson L.
Published: November 2006

U.S. consumers are increasingly concerned about food safety, environmental degradation, and animal welfare at the live animal production stage. In response, meat suppliers are developing food credence certification to secure market access, increase margins, and increase overall demand. The objective of this paper is to characterize the demand and the market potential of a credence certification program for pork in the United States. Information regarding consumer willingness to pay for the conventional and certified products is derived from a latent class random utility model. The willingness to pay estimates are subsequently compared to the costs of implementing the programs at the producer, packing, and retailing stages. One of the findings in this study is that a significant segment of consumers would purchase certified pork at the anticipated marginal cost of certification. Therefore, future studies should consequently focus on the welfare economic implications on consumers and meat suppliers from incomplete adoption of voluntary certification programs on the part of both producers and consumers.

Aux États‐Unis, les consommateurs se préoccupent de plus en plus de la sécurité alimentaire, de la dégradation de l'environnement et du bien‐être des animaux au stade de la production. En réponse à ces inquiétudes, les fournisseurs de viande travaillent à l'élaboration de programmes de certification des aliments pour garantir l'accès au marché, accroître les marges ainsi que la demande globale. Le présent article vise à caractériser la demande et le potentiel de marché d'un programme de certification du porc aux États‐Unis. L'information concernant la volonté de payer du consommateur pour des produits classiques et des produits certifiés a été tirée d'un modèle d'utilité aléatoire à structure latente. Les estimations de la volonté de payer ont ensuite été comparées aux coûts de mise en place des programmes aux stades de la production, de l'abattage et de la vente au détail. L'un des résultats de l'étude a montré qu'un nombre important de consommateurs achèterait du porc certifié au coût marginal prévu de la certification. Des études ultérieures devraient donc se pencher sur les répercussions économiques de l'adoption incomplète des programmes de certification volontaires de la part des producteurs et des consommateurs sur le bien‐être des consommateurs et des fournisseurs de viande.
Consumer Attitudes and Acceptance of CLA‐Enriched Dairy Products
Authors: Peng Yanning , West Gale E. , Wang Cindy
Published: November 2006

Consumers have increasingly recognized the link between health and diet, and are taking special interest in functional foods that promise to enhance health and reduce the risk of diseases. Milk, an excellent source of essential nutrients, as well as an ideal carrier of healthy functional ingredients, holds promise for the development of functional foods. A variety of functional milk products have been launched into the market, such as yogurt, milk, butter and cheese fortified with vitamins, minerals, and omega‐3 fatty acids. Conjugated linoleic acid (CLA), which may help reduce the risk of cancer, heart disease, and obesity, is naturally found in milk. The dairy industry is working actively with scientists to develop CLA‐enriched dairy products to serve Canadian consumers. This study examines consumers' attitudes toward CLA‐enriched products, and identifies several key factors that may help determine consumers' acceptance of these products. The information obtained from this study is useful for the dairy industry to develop marketing strategies for CLA and other functional milk products.

Les consommateurs reconnaissent de plus en plus le lien entre la santé et le régime alimentaire et manifestent un intérêt particulier pour les aliments fonctionnels qui promettent d'améliorer la santé et de diminuer le risque de maladies. Le lait, qui constitue une excellente source d'éléments nutritifs essentiels de même qu'un véhicule idéal d'ingrédients fonctionnels sains, semble prometteur pour la mise au point d'aliments fonctionnels. Une variété de produits laitiers fonctionnels, tels que le yogourt, le lait, le beurre et le fromage enrichis de vitamines, de minéraux et d'acides gras oméga‐3, ont été lancés sur le marché. L'acide linoléique conjugué (ALC), qui pourrait contribuer à réduire les risques de cancer, de maladie du cœur et d'obésité, se trouve naturellement dans le lait. L'industrie laitière collabore activement avec les scientifiques pour mettre au point des produits laitiers enrichis d'ALC pour les consommateurs canadiens. La présente étude a examiné l'attitude des consommateurs envers les produits enrichis d'ALC et a identifié plusieurs facteurs clés qui pourraient aider à déterminer l'acceptation de ces produits de la part des consommateurs. L'information recueillie dans le cadre de la présente étude est utile pour l'industrie laitière qui l'utilisera pour élaborer des stratégies de marketing pour l'ALC et d'autres produits laitiers fonctionnels.
Study on Stabilizing Mechanism of Konjac Glucomannan in Tea Infusions
Authors: Gong Jia‐Shun , Liu Pei‐Ying , Liu Qin‐Jin
Published: November 2006

ABSTRACT:  The stabilizing mechanism of konjac glucomannan (KGM) in tea infusions was studied using a conventional transmission electron microscope (TEM), scanning electron microscope (SEM), ethanol sedimentation, and other methods. As a result, many water‐soluble complexes among the KGM molecules and tea components such as thearubigins (TRs), theaflavins (TFs), total catechins (TC), and tea polyphenols (TPP) were obviously formed in tea infusions with addition of KGM. The aggregations of tea components, which caused tea cream down, were decreased because of KGM addition and the stability of suspended particles in tea‐KGM infusions was enhanced. These findings suggested that the strong adsorption happened among KGM and tea components and particles through strong hydrogen bonding functions. Molecular weight of KGM in tea infusions was smaller than that in water solution. In water solution, it was 4.83 × 105, but in black tea infusions 3.41 × 105, and in oolong tea infusions 3.51 × 105. The experiments also revealed that the tea‐KGM infusions had stronger antielectrolyte coagulation capacity and the static electrification action exists among the molecules of tea infusions. These findings indicated that KGM could be a useful stabilizer for stability of the tea infusions.
Characterization of Aroma‐Active Compounds in Microwave Blanched Peanuts
Authors: Schirack A.V. , Drake M.A. , Sanders T.H. , Sandeep K.P.
Published: November 2006

ABSTRACT: Microwave blanching of peanuts has been explored as an alternative to conventional oven methods based on its speed of operation, energy savings, and efficiency of process control. Although processing times can be greatly reduced, the occurrence of stale/floral and ashy off‐flavors has been reported at high process temperatures. This study examined the chemical compounds responsible for this off‐flavor using solvent extraction/solvent assisted flavor evaporation (SAFE), gas chromatography‐olfactometry (GC/O), gas chromatography‐mass spectrometry (GC/MS), and aroma extract dilution analysis (AEDA). Select compounds were quantified based on AEDA results using SAFE and GC/MS. Quantification, threshold testing, and analysis of model systems revealed increased formation of guaiacol and phenylacetaldehyde in the off‐flavored peanuts, which resulted in the burnt and stale/floral flavors noted by a trained panel.
Subunit‐specific modulation of T‐type calcium channels by zinc
Authors: Traboulsie Achraf , Chemin Jean , Chevalier Marc , Quignard Jean‐François , Nargeot Joël , Lory Philippe
Published: November 2006

Zinc (Zn2+) functions as a signalling molecule in the nervous system and modulates many ionic channels. In this study, we have explored the effects of Zn2+on recombinant T‐type calcium channels (CaV3.1, CaV3.2 and CaV3.3). Using tsA‐201 cells, we demonstrate that CaV3.2 current (IC50, 0.8 μm) is significantly more sensitive to Zn2+than are CaV3.1 and CaV3.3 currents (IC50, 80 μmand ∼160 μm, respectively). This inhibition of CaV3 currents is associated with a shift to more negative membrane potentials of both steady‐state inactivation for CaV3.1, CaV3.2 and CaV3.3 and steady‐state activation for CaV3.1 and CaV3.3 currents. We also document changes in kinetics, especially a significant slowing of the inactivation kinetics for CaV3.1 and CaV3.3, but not for CaV3.2 currents. Notably, deactivation kinetics are significantly slowed for CaV3.3 current (∼100‐fold), but not for CaV3.1 and CaV3.2 currents. Consequently, application of Zn2+results in a significant increase in CaV3.3 current in action potential clamp experiments, while CaV3.1 and CaV3.2 currents are significantly reduced. In neuroblastoma NG 108‐15 cells, the duration of CaV3.3‐mediated action potentials is increased upon Zn2+application, indicating further that Zn2+behaves as a CaV3.3 channel opener. These results demonstrate that Zn2+exhibits differential modulatory effects on T‐type calcium channels, which may partly explain the complex features of Zn2+modulation of the neuronal excitability in normal and disease states.
Brainstem PCO2 modulates phrenic responses to specific carotid body hypoxia in an in situ dual perfused rat preparation
Authors: Day Trevor A. , Wilson Richard J. A.
Published: November 2006

Inputs from central (brainstem) and peripheral (carotid body) respiratory chemoreceptors are coordinated to protect blood gases against potentially deleterious fluctuations. However, the mathematics of the steady‐state interaction between chemoreceptors has been difficult to ascertain. Further, how this interaction affects time‐dependent phenomena (in which chemoresponses depend upon previous experience) is largely unknown. To determine how central PCO2 modulates the response to peripheral chemostimulation in the rat, we utilized an in situ arterially perfused, vagotomized, decerebrate preparation, in which central and peripheral chemoreceptors were perfused separately (i.e. dual perfused preparation (DPP)). We carried out two sets of experiments: in Experiment 1, we alternated steady‐state brainstem PCO2 between 25 and 50 Torr in each preparation, and applied specific carotid body hypoxia (60 Torr PO2 and 40 Torr PCO2) under both conditions; in Experiment 2, we applied four 5 min bouts (separated by 5 min) of specific carotid body hypoxia (60 Torr PO2 and 40 Torr PCO2) while holding the brainstem at either 30 Torr or 50 Torr PCO2. We demonstrate that the level of brainstem PCO2 modulates (a) the magnitude of the phrenic responses to a single step of specific carotid body hypoxia and (b) the magnitude of time‐dependent phenomena. We report that the interaction between chemoreceptors is negative (i.e. hypo‐additive), whereby a lower brainstem PCO2 augments phrenic responses resulting from specific carotid body hypoxia. A negative interaction may underlie the pathophysiology of central sleep apnoea in populations that are chronically hypocapnic.
WNT and DKK Determine Hair Follicle Spacing Through a Reaction-Diffusion Mechanism
Authors: Sick Stefanie , Reinker Stefan , Timmer Jens , Schlake Thomas
Published: November 2006

Mathematical reaction-diffusion models have been suggested to describe formation of animal pigmentation patterns and distribution of epidermal appendages. However, the crucial signals and in vivo mechanisms are still elusive. Here we identify WNT and its inhibitor DKK as primary determinants of murine hair follicle spacing, using a combined experimental and computational modeling approach. Transgenic DKK overexpression reduces overall appendage density. Moderate suppression of endogenous WNT signaling forces follicles to form clusters during an otherwise normal morphogenetic program. These results confirm predictions of a WNT/DKK-specific mathematical model and provide in vivo corroboration of the reaction-diffusion mechanism for epidermal appendage formation.
Giant Ringlike Radio Structures Around Galaxy Cluster Abell 3376
Authors: Bagchi Joydeep , Durret Florence , Neto Gastão B. Lima , Paul Surajit
Published: November 2006

In the current paradigm of cold dark matter cosmology, large-scale structures are assembling through hierarchical clustering of matter. In this process, an important role is played by megaparsec (Mpc)–scale cosmic shock waves, arising in gravity-driven supersonic flows of intergalactic matter onto dark matter–dominated collapsing structures such as pancakes, filaments, and clusters of galaxies. Here, we report Very Large Array telescope observations of giant (∼2 Mpc by 1.6 Mpc), ring-shaped nonthermal radio-emitting structures, found at the outskirts of the rich cluster of galaxies Abell 3376. These structures may trace the elusive shock waves of cosmological large-scale matter flows, which are energetic enough to power them. These radio sources may also be the acceleration sites where magnetic shocks are possibly boosting cosmic-ray particles with energies of up to 10
18
to 10
19
electron volts.
Renewable Hydrogen from Nonvolatile Fuels by Reactive Flash Volatilization
Authors: Salge J. R. , Dreyer B. J. , Dauenhauer P. J. , Schmidt L. D.
Published: November 2006

Droplets of nonvolatile fuels such as soy oil and glucose-water solutions can be flash evaporated by catalytic partial oxidation to produce hydrogen in high yields with a total time in the reactor of less than 50 milliseconds. Pyrolysis, coupled with catalytic oxidation of the fuels and their fragments upon impact with a hot rhodium-cerium catalyst surface, avoids the formation of deactivating carbon layers on the catalyst. The catalytic reactions of these products generate approximately 1 megawatt of heat per square meter, which maintains the catalyst surface above 800°C at high drop impact rates. At these temperatures, heavy fuels can be catalytically transformed directly into hydrogen, carbon monoxide, and other small molecules in very short contact times without the formation of carbon.
Coherent Electronic Fringe Structure in Incommensurate Silver-Silicon Quantum Wells
Authors: Speer N. J. , Tang S.-J. , Miller T. , Chiang T.-C.
Published: November 2006

Atomically uniform silver films grown on highly doped n-type Si(111) substrates show fine-structured electronic fringes near the silicon valence band edge as observed by angle-resolved photoemission. No such fringes are observed for silver films grown on lightly doped n-type substrates or p-type substrates, although all cases exhibited the usual quantum-well states corresponding to electron confinement in the film. The fringes correspond to electronic states extending over the silver film as a quantum well and reaching into the silicon substrate as a quantum slope, with the two parts coherently coupled through an incommensurate interface structure.
Protrudin Induces Neurite Formation by Directional Membrane Trafficking
Authors: Shirane Michiko , Nakayama Keiichi I.
Published: November 2006

Guanosine triphosphatases of the Rab family are key regulators of membrane trafficking, with Rab11 playing a specific role in membrane recycling. We identified a mammalian protein, protrudin, that promoted neurite formation through interaction with the guanosine diphosphate (GDP)–bound form of Rab11. Phosphorylation of protrudin by extracellular signal–regulated kinase (ERK) in response to nerve growth factor promoted protrudin association with Rab11-GDP. Down-regulation of protrudin by RNA interference induced membrane extension in all directions and inhibited neurite formation. Thus, protrudin regulates Rab11-dependent membrane recycling to promote the directional membrane trafficking required for neurite formation.
The Polarity Protein Par-3 Directly Interacts with p75
NTR
to Regulate Myelination
Authors: Chan Jonah R. , Jolicoeur Christine , Yamauchi Junji , Elliott Jimmy , Fawcett James P. , Ng Benjamin K. , Cayouette Michel
Published: November 2006

Cell polarity is critical in various cellular processes ranging from cell migration to asymmetric cell division and axon and dendrite specification. Similarly, myelination by Schwann cells is polarized, but the mechanisms involved remain unclear. Here, we show that the polarity protein Par-3 localizes asymmetrically in Schwann cells at the axon-glial junction and that disruption of Par-3 localization, by overexpression and knockdown, inhibits myelination. Additionally, we show that Par-3 directly associates and recruits the p75 neurotrophin receptor to the axon-glial junction, forming a complex necessary for myelination. Together, these results point to a critical role in the establishment of cell polarity for myelination.
Chewing on the Food Chain
Authors: Katz David L.
Published: November 2006

Six Arguments for a Greener Diet
. How a More Plant-Based Diet Could Save Your Health and the Environment.
By: Michael F. Jacobson and the Staff of the Center for Science in the Public Interest
. Center for Science in the Public Interest, Washington, DC, 2006.248 pp. Paper, $14.95, C$21. ISBN 0-89329-049-1.

The authors argue that a diet with more plant foods and fewer fatty animal products will favor longer, healthier lives while also reducing one's environmental impact.
Alpha Condensed State in 16O
Authors: Funaki Y. , Tohsaki A. , Horiuchi H. , Schuck P. , Röpke G.
Published: November 2006

It is discussed that the recently observed 0+ state at 13.5 MeV in 16 O can be a good candidate of the 4α condensate. The 4α condensed state which is theoretically obtained in the vicinity of the 4α threshold is shown to have a relatively large α decay width, which is in well agreement with the value measured for the 0+ state at 13.5 MeV. The analysis of inelastic form factor of electron scattering to the 4α condensed state is made by artificially varying the size of the 4α condensate. Similarly to the case of Hoyle state, only the magnitude of the form factor is found to depend on its size, while the position of maximum and minimum are not changed.
Measurement of the decay α particle from α cluster states
Authors: Itoh M.
Published: November 2006

The second 2+state in the 10 MeV region of12C was investigated by measuring decay-α particles in the12C nucleus excited by inelastic α scattering at 0°. Angular correlation functions were obtained at backward angles from 115° to 255°. Those for 9.64 MeV 3-, 15.4 MeV 2+, and 18.2 MeV 2+states were good agreement with the PWBA calculation. The third 0+state was also investigated. The coincidence spectra at 245° of decay-α particles seem to be consisted of two 0+components.
Cluster states in13C
Authors: Sasamoto Y. , Kawabata T. , Uesaka T. , Suda K. , Maeda Y. , Sakaguchi S. , Itoh K. , Hatanaka K. , Fujiwara M. , Tamii A. , Shimizu Y. , Nakanishi K. , Kawase K. , Hashimoto H. , Tameshige Y. , Matsubara H. , Itoh M. , Yoshida H. P. , Uchida M.
Published: November 2006

Cross sections for13C (α,α′) reactions at Eα= 400 MeV have been measured to obtain the monopole and quadrupole transition strengths. The excitation strengths are compared with the shell-model predictions. It is suggested that the large monopole strengths observed for the [Formula: see text] and [Formula: see text] states in13C are attributed to the cluster structure of those states.
ON THE RANK FUNCTION OF THE 3-DIMENSIONAL RIGIDITY MATROID
Authors: JACKSON BILL , JORDÁN TIBOR
Published: November 2006

It is an open problem to find a good characterization for independence or, more generally, the rank function in the d-dimensional rigidity matroid of a graph when d ≥ 3. In this paper we give a brief survey of existing lower and upper bounds on the rank of the 3-dimensional rigidity matroid of a graph and introduce a new upper bound, which may lead to the desired good characterization.
WELL-CONSTRAINED COMPLETION AND DECOMPOSITION FOR UNDER-CONSTRAINED GEOMETRIC CONSTRAINT PROBLEMS
Authors: ZHANG GUI-FANG , GAO XIAO-SHAN
Published: November 2006

In this paper, we consider the optimal well-constrained completion problem, that is, for an under-constrained geometric constraint problem, add automatically new constraints in such a way that the new constraint problem G is well-constrained and the set of equations to be solved simultaneously in order to solve G has the smallest size. We propose a polynomial time algorithm which gives a partial solution to the above problem.
GPDOF — A FAST ALGORITHM TO DECOMPOSE UNDER-CONSTRAINED GEOMETRIC CONSTRAINT SYSTEMS: APPLICATION TO 3D MODELING
Authors: TROMBETTONI GILLES , WILCZKOWIAK MARTA
Published: November 2006

Our approach exploits a general-purpose decomposition algorithm, called GPDOF, and a dictionary of very efficient solving procedures, called r-methods, based on theorems of geometry. GPDOF decomposes an equation system into a sequence of small subsystems solved by r-methods, and produces a set of input parameters.1.

Recursive assembly methods (decomposition-recombination), maximum matching based algorithms, and other famous propagation schema are not well-suited or cannot be easily extended to tackle geometric constraint systems that are under-constrained. In this paper, we show experimentally that, provided that redundant constraints have been removed from the system, GPDOF can quickly decompose large under-constrained systems of geometrical constraints.

We have validated our approach by reconstructing, from images, 3D models of buildings using interactively introduced geometrical constraints. Models satisfying the set of linear, bilinear and quadratic geometric constraints are optimized to fit the image information. Our models contain several hundreds of equations. The constraint system is decomposed in a few seconds, and can then be solved in hundredths of seconds.
TwoN-linked glycans are required to maintain the transport activity of the bile salt export pump (ABCB11) in MDCK II cells
Authors: Mochizuki Kaori , Kagawa Tatehiro , Numari Asano , Harris Matthew J. , Itoh Johbu , Watanabe Norihito , Mine Tetsuya , Arias Irwin M.
Published: November 2006

The aim of this study was to determine the role of N-linked glycosylation in protein stability, intracellular trafficking, and bile acid transport activity of the bile salt export pump [Bsep (ATP-binding cassette B11)]. Rat Bsep was fused with yellow fluorescent protein, and the following mutants, in which Asn residues of putative glycosylation sites (Asn109, Asn116, Asn122, and Asn125) were sequentially replaced with Gln, were constructed by site-directed mutagenesis: single N109Q, double N109Q + N116Q, triple N109Q + N116Q + N122Q, and quadruple N109Q + N116Q + N122Q + N125Q. Immunoblot and glycosidase cleavage analysis demonstrated that each site was glycosylated. Removal of glycans decreased taurocholate transport activity as determined in polarized MDCK II cells. This decrease resulted from rapid decay of the mutant Bsep protein; biochemical half-lives were 3.76, 3.65, 3.24, 1.35, and 0.52 h in wild-type, single-mutant, double-mutant, triple-mutant, and quadruple-mutant cells, respectively. Wild-type and single- and double-mutant proteins were distributed exclusively along the apical membranes, whereas triple- and quadruple-mutant proteins remained intracellular. MG-132 but not bafilomycin A1extended the half-life, suggesting a role for the proteasome in Bsep degradation. To determine whether a specific glycosylation site or the number of glycans was critical for protein stability, we studied the protein expression of combinations of N-glycan-deficient mutants and observed that Bsep with one glycan was considerably unstable compared with Bsep harboring two or more glycans. In conclusion, at least two N-linked glycans are required for Bsep protein stability, intracellular trafficking, and function in the apical membrane.
Baroreceptor reflex regulation in anesthetized transgenic rats with low glia-derived angiotensinogen
Authors: Sakima Atsushi , Averill David B. , Kasper Sherry O. , Jackson LaRhonda , Ganten Detlev , Ferrario Carlos M. , Gallagher Patricia E. , Diz Debra I.
Published: November 2006

Endogenous angiotensin (ANG) II and ANG-(1–7) act at the nucleus tractus solitarius (NTS) to differentially modulate neural control of the circulation. The role of these peptides endogenous to NTS on cardiovascular reflex function was investigated in transgenic rats with low brain angiotensinogen (Aogen) due to glial overexpression of an antisense to Aogen (ASrAOGEN) and in Sprague-Dawley (SD) rats. Arterial baroreceptor reflex sensitivity (BRS) for control of heart rate (HR) in response to increases in mean arterial pressure (MAP) was tested before and after bilateral microinjection of the angiotensin type 1 (AT1) receptor blocker candesartan or the ANG-(1–7) receptor blocker (d-Ala7)-ANG-(1–7) into the NTS of urethane-chloralose-anesthetized ASrAOGEN and SD rats. Baseline MAP was higher in ASrAOGEN than in SD rats under anesthesia ( P < 0.01). Injection of candesartan or (d-Ala7)-ANG-(1–7) decreased MAP ( P < 0.01) and HR ( P < 0.05) in ASrAOGEN, but not SD, rats. The BRS at baseline was similar in ASrAOGEN and SD rats. Candesartan increased BRS by 41% in SD rats ( P < 0.01) but was without effect in ASrAOGEN rats. In contrast, the reduction in BRS after (d-Ala7)-ANG-(1–7) administration was comparable in SD (31%) and ASrAOGEN rats (34%). These findings indicate that the absence of glia-derived Aogen is associated with 1) an increase in MAP under anesthesia mediated via AT1 and ANG-(1–7) receptors within the NTS, 2) the absence of an endogenous ANG II contribution to tonic inhibition of BRS, and 3) a continued contribution of endogenous ANG-(1–7) to tonic enhancement of BRS.