bluuebunny/crossref_metadata_2025 huggingface dataset:
Application of aluminium honeycomb sandwich panel as an energy absorber of high-speed train nose
Authors: Amraei M , Shahravi M , Noori Z , Lenjani A
Published: April 2013

Since train’s frontal nose is the first part of the train which is damaged at the frontal impact, specific attention should be paid to the design of this part. In this study, an effort has been conducted to the design of a nose with light weight which can absorb maximum amount of energy that is possible during a frontal collision. To this aim and with attention to aerodynamic considerations, application of aluminium honeycomb sandwich panel has been studied. This paper includes two main parts. The first part is dedicated to the simulation of aluminium honeycomb sandwich panel, while the frontal collision of nose with different internal layer thicknesses of honeycomb and various nose lengths have been simulated in the second part. Finite element method using LS-DYNA commercial package has been used for the numerical simulation. The results have been validated with available experimental results and an acceptable agreement has been observed.
Nonlinear free and forced vibrations of anti-symmetric angle-ply hybrid laminated rectangular plates
Authors: Shooshtari A , Razavi S
Published: April 2013

In this article, the nonlinear equations of motion for anti-symmetric angle-ply composite rectangular plates have been derived using the first-order shear deformation theory, including shear deformation and rotary inertia. By using the Galerkin method, five coupled nonlinear partial differential equations of motion are reduced to a nonlinear ordinary differential equation. Then, the multiple time scales method is used to solve the obtained equation and to derive an analytical relation for the nonlinear frequency. Results are compared with the literature and good agreement is achieved. After proving the validity of this study, nonlinear free and forced vibration of a fiber metal laminated rectangular plate have been studied and the effects of some system parameters on the nonlinear behavior of the FML rectangular plate have been investigated.
Dielectric property of unidirectional triangle-shape carbon fiber reinforced polymeric composites
Authors: Liu Xin , Wang Rongguo , Wu Zhanjun , Liu Wenbo
Published: April 2013

Triangle-shape carbon fiber reinforced polymeric composites is a plausible material for fabricating the radar absorbing structure. In order to design the effective electromagnetic wave absorber, the dielectric properties of its constituents are required in the target frequency band. In this paper, the unidirectional triangle-shape carbon fiber/epoxy composites were manufactured and the carbon fiber volume fraction of composite materials was measured to be about 46%. And then the permittivities of specimens were tested with the rectangle waveguide method in the vertical direction and in the parallel direction. The theoretical models and prediction equations for estimating permittivity of the unidirectional triangle-shape carbon fiber/epoxy composites were proposed with respect to the fiber volume fractions, the cross-section shape of fiber, the fiber orientations and the permittivity of components. It was found that the theoretical values agreed well with the experimental results.
Polyamide-6-based composites reinforced with pristine or functionalized multi-walled carbon nanotubes produced using melt extrusion technique
Authors: Mahmood Nasir , Islam Mohammad , Hameed Asad , Saeed Shaukat , Khan Ahmad Nawaz
Published: April 2013

Polyamide-6-based composites with pristine or functionalized multi-walled carbon nanotubes were produced using melt extrusion technique. After chemical functionalization, defect formation and attachment of carboxylic (−COOH) or amine (−NH2) groups on carbon nanotubes was confirmed from high-resolution transmission electron microscope and Fourier transform infra-red spectroscope studies. Carbon nanotubes incorporation promoted growth of α-form crystals with enhanced thermal stability through increase in crystallization temperature from 162 to 192℃. Dynamic mechanical thermal analysis (DMTA) indirectly pointed out to a homogeneous, uniform dispersion of nanotubes with reduction in free volume of the polymer, exhibiting a slight increase in glass transition temperature and a significant drop in coefficient of thermal expansion value. Composites containing 0.5 wt% NH2-carbon nanotubes show increases in elastic modulus and tensile strength by ∼60 and 76%, respectively. Uniform dispersion and high interfacial strength was manifested by drop in strain to failure and lack of evidence of carbon nanotubes debonding from the matrix.
Epidemic simulation of a large-scale social contact network on GPU clusters
Authors: Zou Peng , Lü Ya-shuai , Wu Ling-da , Chen Li-li , Yao Yi-ping
Published: April 2013

Computer simulation is an important tool for studying epidemic dynamics. Owing to the scales and runtime speed requirements, the simulations of large-scale pandemic diseases such as severe acute respiratory syndrome (SARS) and H1N1 influenza usually require high-performance parallel simulation or computation. Previous works on the parallel simulations of large-scale epidemic were implemented on traditional general purpose CPU-based platforms or clusters. As more and more high-performance computation clusters are being built with so-called general-purpose graphics cards, this paper presents the implementation and optimization techniques for social contact network-based large-scale epidemic simulation on GPU clusters. Compared with previous works, this paper focuses on (1) how to efficiently implement the contact network-based parallel epidemic simulation on GPUs, and (2) how to hide communication latencies between processing nodes to improve scalability. Our proposed techniques are implemented and tested on a commodity cluster whose processing nodes are equipped with GPGPUs. The experimental results show that, for the simulation of 20 million individuals and 1.2 billion host contacts on 80 nodes, the execution on GPUs can achieve 7.4×−11.7× speedup over the execution on CPUs.
A novel kinematic design, analysis and simulation tool for general Stewart platforms
Authors: Inner Burak , Kucuk Serdar
Published: April 2013

In this paper, a general Stewart Platform Simulation tool (STEWSIM) is developed for robot designers and researchers. The STEWSIM uses an efficient connection matrix algorithm that has been developed for kinematic design of all possible types of general Stewart platforms (GSPs), such as 3×3, 3×4, 3×5 … 6×5 and 6×6 with an arbitrary number of legs varying between three and six. This new interactive simulation software based on the MATLAB Graphical User Interface (GUI) provides a suite of analyses, such as inverse and forward kinematics, Jacobian matrix, dexterity, workspace, singularity analysis and trajectory planning, using different kinds of roll-pitch-yaw or Euler angle sets. The STEWSIM also provides the visualization of the GSPs, graphical representation of the workspace, and graphic animation of trajectories specified by inverse kinematics in three-dimensional space. Furthermore, it provides an environment to compare the kinematic performances of the designed GSPs with arbitrary configuration. As a kinematic design, analysis and simulation software, the STEWSIM provides researchers with the ability to change the parameters interactively for designing their manipulators with optimum specifications, such as leg lengths and attachment points. The usage of this simulation tool may result in new types of feasible robotic manipulators that can be used for practical applications in industry.
Discursive Framings of Low Carbon Urban Transitions: The Contested Geographies of ‘Satellite Settlements’ in the Czech Republic
Authors: Petrova Saska , Posová Darina , House Adam , Sýkora Ludek
Published: April 2013

The discursive and representational aspects of the multiple political, economic and cultural challenges associated with low carbon urban transitions remain insufficiently explored in the academic literature. This is particularly true in the post-communist states of eastern and central Europe, which have been undergoing an additional transition of their own—from a centrally planned to a market-based economy. This paper, therefore, explores the manner in which climate change and sustainability narratives have been implicated in the development of ‘satellite settlements’—a specific form of sprawl present in the Czech Republic. Much of the paper is focused on investigating the discursive framings of such areas by relevant state policies and the national media in this country. Several key themes and discursive shifts in the representation of satellite settlements have been detected. Such changes may be connected to wider interactions among the dynamics of post-communist and low-carbon urban transition.
Neoliberal Urban Environmentalism and the Adaptive City: Towards a Critical Urban Theory and Climate Change
Authors: Whitehead Mark
Published: April 2013

This paper explores the potential contribution of critical urban theory to the intellectual and political debates surrounding climate change. While it is possible to identify an emerging strand of critical enquiry concerning the role of cities in facilitating climate change mitigation and adaptation strategies, this paper argues that the full implications of critical urban theory to climate change studies have yet to be realised. In this paper, critical urban theory is understood as an approach (or set of approaches) to the city that recognises the contingent form of urban politics and policy, while asserting that, far from being an inevitable and politically neutral process, urbanisation is an expression of intersecting regimes of social power. This paper utilises critical urban theory as a basis for analysing emerging urban climate adaptation strategies. The analysis presented here asserts that contemporary adaptation policies are being framed by neoliberal practices of market-oriented governance, enhanced privatisation and urban environmental entrepreneurialism. This paper exposes some of the key contradictions that are inherent within neoliberalised urban climate change adaptation strategies and suggests how it might be possible to develop more progressive adaptation regimes.
Grassroots Localisation? The Scalar Potential of and Limits of the ‘Transition’ Approach to Climate Change and Resource Constraint
Authors: North Peter , Longhurst Noel
Published: April 2013

This paper engages with the progressive politics of climate change and resource constraint developed by the Transition ‘movement’ which looks to develop a positive local politics of the transition to a low carbon economy and society. At the heart of this politics is a vision of economic localisation rooted in a geographical imaginary of market towns with agricultural hinterlands. Consequently, the question of how the Transition model can be applied in urban settings has not been clear, leading to the implicit assumption that urban Transition initiatives are more complex and difficult. In contrast, this paper argues that the plasticity of Transition politics means that, in some cases, an urban context might be more productive for the development of Transition initiatives because it allows for a greater diversity of political action as well as providing a density of networks and resources that can be critical for the survival of grassroots interventions.
The Intermediary Organisation of Low Carbon Cities: A Comparative Analysis of Transitions in Greater London and Greater Manchester
Authors: Hodson Michael , Marvin Simon , Bulkeley Harriet
Published: April 2013

Making a low carbon economic future for the UK has been declared a key priority by both the previous Labour government and also the current coalition government. Yet there is a large gap between the symbolic representations of a low carbon future and their material manifestations in low carbon technologies and infrastructure in particular places. This paper addresses this gap through focusing on the organisation of urban low carbon transition activity. There is often significant capacity to act in reconfiguring urban energy systems that remains latent due to a missing organisational context for its co-ordination according to a mutually defined rationale or vision. This paper develops a conceptual framework to demonstrate and understand different modes of urban energy intermediation. Examples are used of intermediary organisation in London and Manchester to understand the strengths and partiality of each mode of intermediation and the necessity to integrate these different aspects of urban intermediary governance.
The Socio-institutional Dynamics of Urban Climate Governance: A Comparative Analysis of Innovation and Change in Durban (KZN, South Africa) and Portland (OR, USA)
Authors: Aylett Alex
Published: April 2013

The past two decades have seen an impressive expansion of municipal engagement with climate change. Yet while interest has broadened, actions remain shallow. This is in part because climate policies fit uneasily into existing bureaucratic structures and practices. Effective climate programmes require adaptive and innovative responses that span departmental divisions. This challenges siloised municipal offices that are embedded in their own organisational cultures and technical practices. Understanding those challenges is crucial to understanding urban responses to climate change, but they remain critically understudied. This paper helps to fill that gap by looking at the experiences of two cities, Durban (KZN, South Africa) and Portland (OR, USA) as they attempt to put in place integrated responses to climate change. To do so, it brings together complementary critical perspectives drawn from the study of bureaucracies and complex institutions in sociology and geography. This hybrid critical framework is used to elaborate on both the organisational barriers that inhibit effective responses to climate change, and approaches that can be used to enable change and innovation.
The Uneven Localisation of Climate Action in Metropolitan Seattle
Authors: Dierwechter Yonn , Wessells Anne Taufen
Published: April 2013

As in other countries, public authorities in the US have initiated an array of experiments collectively designed to mitigate the threat posed by global warming. This paper considers the implementation of global climate protection in the Seattle metropolitan region of Washington State. Specifically, the discussion focuses on regulatory, institutional and investment changes within the handful of municipalities formally pledged to address carbon goals as articulated by their statutory participation in the US Mayors’ Climate Protection Agreement. While enrollment in such networked spaces has created crucial momentum for practical policy action, the hardest work is just starting: namely, transforming the physical, institutional, economic and cultural constitution of actually existing political communities. Interrogating new data gleaned from recent research on local ‘cool city’ developments, the discussion assesses overall progress within the context of broader debates in the extant literature on local planning and policy for global climate action.
Cities and Climate Change: The Precedents and Why They Matter
Authors: Hebbert Michael , Jankovic Vladimir
Published: April 2013

This paper reviews the long tradition of city-scale climatological and meteorological applications prior to the emergence in the 1990s of early work on the urban/global climate change interface. It shows how ‘valuing and seeing the urban’ came to be achieved within modern scientific meteorology and how in a limited but significant set of cases that science has contributed to urban practice. The paper traces the evolution of urban climatology since 1950 as a distinct research field within physical geography and meteorology, and its transition from observational monographs to process modelling; reviews the precedents, successful or otherwise, of knowledge transfer from science into public action through climatically aware regulation or design of urban environment; and notes the neglect of these precedents in contemporary climate change discourse—a serious omission.
A 12-Year Content Analysis of the Journal of Black Psychology (2000-2011)
Authors: Cokley Kevin , Awosogba Olufunke , Taylor Desire
Published: April 2013

A content analysis was conducted of research published in the Journal of Black Psychology ( JBP) during a 12-year period (2000-2011). A total of 276 articles were classified into 17 content categories. Similar to the previous JBP content analysis, the most frequently published authors and institutions were identified and ranked. The most highly cited articles were also identified. In addition, gender-focused articles and articles involving racial/ethnic group comparisons were identified. The most popular areas of research and publication in the JBP were in mental health and well-being, personality and identity (i.e., racial identity), culture, and physiological functioning and health psychology. These four categories accounted for 57% of the articles published. Results of this content analysis indicate a sharp increase in research on mental health and culture, while other areas remained consistent with the previous JBP content analysis. The dearth of African-centered psychological research was also noted. Implications for the field of Black psychology in the areas of African-centered research, defining Black psychology, and conducting race comparative research are discussed.
Concepts of Happiness Across Time and Cultures
Authors: Oishi Shigehiro , Graham Jesse , Kesebir Selin , Galinha Iolanda Costa
Published: April 2013

We explored cultural and historical variations in concepts of happiness. First, we analyzed the definitions of happiness in dictionaries from 30 nations to understand cultural similarities and differences in happiness concepts. Second, we analyzed the definition of happiness in Webster’s dictionaries from 1850 to the present day to understand historical changes in American English. Third, we coded the State of the Union addresses given by U.S. presidents from 1790 to 2010. Finally, we investigated the appearance of the phrases happy nation versus happy person in Google’s Ngram Viewer from 1800 to 2008. Across cultures and time, happiness was most frequently defined as good luck and favorable external conditions. However, in American English, this definition was replaced by definitions focused on favorable internal feeling states. Our findings highlight the value of a historical perspective in the study of psychological concepts.
Observed Score and True Score Equating Procedures for Multidimensional Item Response Theory
Authors: Brossman Bradley G. , Lee Won-Chan
Published: April 2013

The purpose of this research was to develop observed score and true score equating procedures to be used in conjunction with the multidimensional item response theory (MIRT) framework. Three equating procedures—two observed score procedures and one true score procedure—were created and described in detail. One observed score procedure was presented as a direct extension of unidimensional IRT (UIRT) observed score equating and is referred to as the “Full MIRT Observed Score Equating Procedure.” The true score procedure and the second observed score procedure incorporated unidimensional approximation procedures to equate exams using UIRT equating principles. These procedures are referred to as the “Unidimensional Approximation of MIRT True Score Equating Procedure” and the “Unidimensional Approximation of MIRT Observed Score Equating Procedure,” respectively. Three exams were used to conduct UIRT observed score and true score equating, MIRT observed score and true score equating, and equipercentile equating. The equipercentile equating procedure was conducted for the purpose of comparison because this procedure does not explicitly violate the IRT assumption of unidimensionality. Results indicated that the MIRT equating procedures performed more similarly to the equipercentile equating procedure than the UIRT equating procedures, presumably due to the violation of the unidimensionality assumption under the UIRT equating procedures.
Addressing Remnants of the Past
Authors: Spina Steven F.
Published: April 2013

Local governments, along with other American institutions, have integrated culturally and ethnically diverse residents into the mainstream of society. Yet, vestiges of segregation and exclusion continue to impact quality of life issues for minorities. These historical remnants pose equity, ethical, and practical dilemmas for local government managers as they wrestle with delivery and access of services and corrections of past environmental injustices for all residents. This article explores how these holdovers continue to challenge managers today and seeks from a practitioner’s point of view to provide methods to rectify these inequalities.
A 28-day Gavage Toxicity Study in Male Fischer 344 Rats with 2-methylfuran
Authors: Gill Santokh S. , Kavanagh Meghan , Cherry Wendy , Barker Michael , Weld Madeline , Cooke Gerard M.
Published: April 2013

In most thermally treated products, a series of alkylated furan derivatives have been found, in particular 2-substituted alkylfurans such as 2-methylfuran. These methyl analogs are metabolically activated in a similar fashion as the parent furan, yielding highly reactive unsaturated dialdehydes. There is currently limited toxicological data available for 2-methyl furan exposure by any route that makes conducting a risk assessment difficult. In this pilot study, we report the general toxicology findings affecting tissue morphology, histopathology, clinical biochemistry, and hematology in a 28-day gavage study. The liver was the primary target organ that developed dose-dependent toxicity. Relative liver weights were increased by 42% at 25.0 mg/kg/body weight (bw)/day. Histological changes in the liver were observed at 0.4, 1.5, 3.0, 6.0, 12.0, and 25.0 mg/kg bw/day. These changes were not accompanied by clinical changes in the serum enzyme markers such as alanine transaminase, alkaline phosphatase, and aspartate transaminase. Clinical biochemistry markers for kidney were altered, but these were not accompanied by histological changes. The prostate was significantly decreased in size at the 25.0 mg/kg bw/day dose of 2-methyfuran. Some hematological parameters were also altered.
Consensus Diagnoses and Mode of Action for the Formation of Gastric Tumors in Rats Treated with the Chloroacetanilide Herbicides Alachlor and Butachlor
Authors: Furukawa Satoshi , Harada Takanori , Thake Daryl , Iatropoulos Michael J. , Sherman James H.
Published: April 2013

A panel of pathologists (Panel) was formed to evaluate the pathogenesis and human relevance of tumors that developed in the fundic region of rat stomachs in carcinogenicity and mechanistic studies with alachlor and butachlor. The Panel evaluated stomach sections stained with hematoxylin and eosin, neuron-specific enolase, and chromogranin A to determine the presence and relative proportion of enterochromaffin-like (ECL) cells in the tumors and concluded all tumors were derived from ECL cells. Biochemical and pathological data demonstrated the tumor formation involved a nongenotoxic threshold mode of action (MOA) initially characterized by profound atrophy of the glandular fundic mucosa that affected gastric glands, but not surface epithelium. This resulted in a substantial loss of parietal cells and a compensatory mucosal cell proliferation. The loss of parietal cells caused a marked increase in gastric pH (hypochlorhydria), leading to sustained and profound hypergastrinemia. The mucosal atrophy, together with the increased gastrin, stimulated cell growth in one or more ECL cell populations, resulting in neoplasia. ECL cell autocrine and paracrine effects led to dedifferentiation of ECL cell tumors. The Panel concluded the tumors develop via a threshold-dependent nongenotoxic MOA, under conditions not relevant to humans.
Regulatory Forum Commentary
Authors: Keenan Charlotte M. , Goodman Dawn G.
Published: April 2013

During 2011, International Harmonization of Nomenclature and Diagnostic Criteria for Lesions in Rats and Mice (INHAND) Global Editorial Steering Committee representatives had discussions with representatives of the Food and Drug Administration (FDA) Center for Drug Evaluation and Research (CDER), Clinical Data Interchange Standards Consortium (CDISC), and the National Cancer Institute (NCI) Enterprise Vocabulary Services (EVS) to examine the potential use of INHAND terminology for SEND (Standard for Exchange of Nonclinical Data) submissions to the FDA. The interest in utilizing the INHAND nomenclature, based on input from industry and government toxicologists as well as information technology specialists, suggests that there will be wide acceptance of INHAND nomenclature. The purpose of this article is 2-fold: (1) to provide a brief historical background on the development of SEND and how it is structured and (2) to discuss the impact of SEND on toxicologic pathology and the role of INHAND.
From the Embodied Mind to the Social Brain
Authors: Bascom Robert
Published: April 2013

In recent decades, scholars in the fields of anthropology, social psychology, cognitive linguistics, and neuroscience have contributed several key complementary insights related to the negotiation of meaning in communication. The first is that the way our bodies experience the world forms the way we think about everything. Another is that the negotiations of social identity and interpersonal relations are precursors to the rest of our negotiations of meaning. Finally, cultural reproduction accounts for a good deal of what we believe are our own ideas, thoughts, and experiences.
How Could Something So Right Be So Wrong? OT References to the Left and Right Hand
Authors: Zogbo Lynell
Published: April 2013

Cross-culturally the left hand is considered the lesser member of the right-left pair, giving rise to right- and left-based linguistic expressions favoring the right hand. In West Africa, left-handedness has positive and negative connotations: while often evoking virility and military prowess, it also connotes impurity, weakness, awkwardness, and sometimes stupidity. After exploring literal and figurative uses of the right and left in the OT, we ask, How does/can an African audience interpret the favoring of the right hand in biblical texts? What are possible readings of the left-handed Benjaminites in the Book of Judges? What are the implications for translation and translator helps?
On Portions, Nostrils, and Anger—A Crux Interpretum in 1 Samuel 1.5
Authors: Sipilä Seppo
Published: April 2013

This article discusses the interpretation of the “portion one of nostrils” that Elkanah gave to Hannah in 1 Sam 1.5. The paper analyses several ancient and modern suggestions against the text itself. A look at the way the Hebrew word אפים is used by the biblical authors reveals that there is only one logical interpretation of the verse. A “portion one of nostrils” must mean an angry portion.
Direct and indirect effects of attachment orientation on relationship quality and loneliness in married couples
Authors: Givertz Michelle , Woszidlo Alesia , Segrin Chris , Knutson Kris
Published: April 2013

This study tested the prediction that spouses’ insecure attachment orientation would be negatively associated with relationship quality. It was further predicted that there would be indirect effects of attachment orientation on spouses’ relationship quality through interpersonal trust as well as indirect effects of attachment orientation on loneliness through spouses’ relationship quality. Predictions were tested on 225 married couples that completed measures of attachment orientation, personal commitment, dedication commitment, interpersonal trust, loneliness, and marital satisfaction. Tests of actor–partner interdependence revealed that insecure attachment (i.e., anxious and avoidant) was associated with lower relationship quality and that one partner’s insecure attachment was associated with his/her spouse’s report of lower relationship quality. Actor–partner mediator models revealed that interpersonal trust mediated the relationship between attachment orientation and relationship quality; insecure attachment was associated with lower levels of interpersonal trust and, in turn, lower relationship quality, both individually and dyadically. Similarly, relationship quality mediated the relationship between attachment orientation and loneliness; insecure attachment was associated with lower relationship quality and, in turn, higher levels of loneliness both individually and dyadically.
Feeling like part of a team
Authors: Don Brian P. , Biehle Susanne N. , Mickelson Kristin D.
Published: April 2013

Prior research has established the importance of co-parenting for child outcomes, yet little is known about how co-parenting influences parents themselves. The current study expands on the prior literature by examining an important aspect of co-parenting, perceived parenting agreement, and exploring the longitudinal association of perceived parenting agreement with new parents’ depression, positive affect, and relationship satisfaction during the transition to parenthood. Using a dyadic approach, results indicated there were significant actor effects of parenting agreement on both mothers’ and fathers’ mental health outcomes, such that greater agreement predicted better subsequent mental health. Perceived parenting agreement was also significantly associated with subsequent relationship satisfaction for mothers only, such that greater perceived agreement by both the mother (actor effect) and the father (partner effect) predicted greater subsequent maternal relationship satisfaction. Our results suggest perceptions of parenting agreement are important for new parents’ mental health and maternal relationship satisfaction during the transition to parenthood.
P300 during response inhibition is associated with ad-lib alcohol consumption in social drinkers
Authors: Jones Andrew , Field Matt , Christiansen Paul , Stancak Andrej
Published: April 2013

Reduced amplitude of the cortical P300 event-related potential (ERP) component during response inhibition is associated with vulnerability to alcohol use disorders. In the current study, we investigated the effect of an experimental manipulation of response conflict on the amplitude of the P300 component during response inhibition, and examined whether individual differences in the amplitude of this P300 component would predict voluntary ad-lib alcohol consumption, in social drinkers. Using a repeated measures design, 16 participants performed a stop-signal task after receiving instructions that either emphasised or de-emphasised response conflict while their electroencephalogram (EEG) was concurrently recorded, before their ad-lib drinking was assessed. Results revealed that task instructions had the predicted effects on behavioural indices of response inhibition and the associated P300 components. Most importantly, individual differences in the amplitude of P300 subcomponents during response inhibition were negatively correlated with ad-lib alcohol consumption. Results provide the first experimental support for theoretical models that posit that reduced amplitude of the P300 during response inhibition is associated with alcohol-seeking behaviour in humans.
Cooperative regulation of anxiety and panic-related defensive behaviors in the rat periaqueductal grey matter by 5-HT1A and µ-receptors
Authors: Roncon Camila M , Biesdorf Carla , Coimbra Norberto C , Audi Elisabeth A , Zangrossi Hélio , Graeff Frederico G
Published: April 2013

Previous results with the elevated T-maze (ETM) test indicate that the antipanic action of serotonin (5-HT) in the dorsal periaqueductal grey (dPAG) depends on the activation endogenous opioid peptides. The aim of the present work was to investigate the interaction between opioid- and serotonin-mediated neurotransmission in the modulation of defensive responses in rats submitted to the ETM. The obtained results showed that intra-dPAG administration of morphine significantly increased escape latency, a panicolytic-like effect that was blocked by pre-treatment with intra-dPAG injection of either naloxone or the 5-HT1A antagonist N-[2-[4-(2-methoxyphenyl)-1 piperazinyl] ethyl] -N- 2- pyridinyl-ciclohexanecarboxamide maleate (WAY-100635). In addition, previous administration of naloxone antagonized both the anti-escape and the anti-avoidance (anxiolytic-like) effect of the 5-HT1A agonist (±)-8-hydroxy-2-(di-n-propylamino)tetralin hydrobromide (8-OH-DPAT), but did not affect the anti-escape effect of the 5-HT2A agonist (±)-2,5-dimethoxy-4-iodoamphetamine hydrochloride (DOI). Moreover, the combination of sub-effective doses of locally administered 5-HT and morphine significantly impaired ETM escape performance. Finally, the µ-antagonist D-PHE-CYS-TYR-D-TRP-ORN-THR-PEN (CTOP) blocked the anti-avoidance as well as the anti-escape effect of 8-OHDPAT, and the association of sub-effective doses of the µ-opioid receptor agonist [D-Ala2, N-Me-Phe4, Gly5-ol]-enkephalin acetate salt (DAMGO) and of 8-OHDPAT had anti-escape and anti-avoidance effects in the ETM. These results suggest a synergic interaction between the 5-HT1A and the µ-opioid receptor at post-synaptic level on neurons of the dPAG that regulate proximal defense, theoretically related to panic attacks.
Probabilistic movement modeling for intention inference in human–robot interaction
Authors: Wang Zhikun , Mülling Katharina , Deisenroth Marc Peter , Ben Amor Heni , Vogt David , Schölkopf Bernhard , Peters Jan
Published: April 2013

Intention inference can be an essential step toward efficient human–robot interaction. For this purpose, we propose the Intention-Driven Dynamics Model (IDDM) to probabilistically model the generative process of movements that are directed by the intention. The IDDM allows the intention to be inferred from observed movements using Bayes’ theorem. The IDDM simultaneously finds a latent state representation of noisy and high-dimensional observations, and models the intention-driven dynamics in the latent states. As most robotics applications are subject to real-time constraints, we develop an efficient online algorithm that allows for real-time intention inference. Two human–robot interaction scenarios, i.e. target prediction for robot table tennis and action recognition for interactive humanoid robots, are used to evaluate the performance of our inference algorithm. In both intention inference tasks, the proposed algorithm achieves substantial improvements over support vector machines and Gaussian processes.
Generation of whole-body optimal dynamic multi-contact motions
Authors: Lengagne Sébastien , Vaillant Joris , Yoshida Eiichi , Kheddar Abderrahmane
Published: April 2013

We propose a method to plan optimal whole-body dynamic motion in multi-contact non-gaited transitions. Using a B-spline time parameterization for the active joints, we turn the motion-planning problem into a semi-infinite programming formulation that is solved by nonlinear optimization techniques. Our main contribution lies in producing constraint-satisfaction guaranteed motions for any time grid. Indeed, we use Taylor series expansion to approximate the dynamic and kinematic models over fixed successive time intervals, and transform the problem (constraints and cost functions) into time polynomials which coefficients are function of the optimization variables. The evaluation of the constraints turns then into computation of extrema (over each time interval) that are given to the solver. We also account for collisions and self-collisions constraints that have not a closed-form expression over the time. We address the problem of the balance within the optimization problem and demonstrate that generating whole-body multi-contact dynamic motion for complex tasks is possible and can be tractable, although still time consuming. We discuss thoroughly the planning of a sitting motion with the HRP-2 humanoid robot and assess our method with several other complex scenarios.
Relationship between the migratory, metabolic and proliferative ability of fibrochondrocytes and the meniscal fragment size: an in vivo study
Authors: Dai Zhu , Li Kang-Hua , Chen Zhi-Wei , Hou Zi-Xin , Deng Yan
Published: April 2013

Objective

To investigate the migratory, metabolic and proliferative ability of rabbit fibrochondrocytes in meniscal fragments of different sizes under an in vivo subcutaneous environment.

Methods

Adult, male, New Zealand white rabbit menisci were harvested and the inner two-thirds of each were minced into different sizes: 0.5 × 0.5 × 0.5 mm (group A); 1.0 × 1.0 × 1.0 mm (group B); 2.0 × 2.0 × 2.0 mm (group C). Meniscal fragments were packed into a fascia sheath, then implanted subcutaneously. At weeks 1, 2 and 3 postimplantation, meniscal fragments were harvested; cell migration and viability were then evaluated by confocal laser scanning microscopy and haematoxylin and eosin staining. Aggrecan was detected using Safranin O and Fast Green staining, and protein levels of types I and II collagen, and proliferating cell nuclear antigen (PCNA), were evaluated by immunohistochemistry.

Results

Protein levels of types I and II collagen and PCNA, and fibrochondrocyte migration, were highest in group A compared with groups B and C, but aggrecan staining remained the same across the groups.

Conclusion

There was an inverse relationship between the migratory, metabolic and proliferative abilities of rabbit fibrochondrocytes and meniscal fragment size.
Framing effects in medical situations: Distinctions of attribute, goal and risky choice frames
Authors: Peng Jiaxi , Jiang Yuan , Miao Danmin , Li Rui , Xiao Wei
Published: April 2013

Objective

To verify whether three different framing effects (risky choice, attribute and goal) exist in simulated medical situations and to analyse any differences.

Methods

Medical decision-making problems were established, relating to medical skill evaluation, patient compliance and a selection of treatment options. All problems were described in positive and negative frame conditions.

Results

Significantly more positive evaluations were made if the doctor’s medical records were described as ‘of 100 patients, 70 patients became better’ compared with those described as ‘of 100 patients, 30 patients didn’t become better’. Doctor’s advice described in a negative frame resulted in significantly more decisions to comply, compared with advice described in a positive frame. Treatment options described in terms of survival rates resulted in significantly more adventurous choices compared with options described in terms of mortality rates. Decision-making reversal appeared in the risky choice and attribute frames, but not the goal frame.

Conclusions

Framing effects were shown to exist in simulated medical situations, but there were significant differences among the three kinds of such effects.
Proteomic profiling of heterotopic heart-transplanted rats using surface-enhanced laser desorption/ionization time-of-flight mass spectrometry: Potential biomarkers and drug targets
Authors: Bao Yang , Xiu Dian-Rong , Zhang Li
Published: April 2013

Objective

Methotrexate and rapamycin demonstrate an additive effect in prolonging cardiac allograft survival in a major histocompatibility complex mismatched rat model. The present study aimed to identify functional proteins involved in the allograft-protective effects of these two agents and reveal potential diagnostic markers for treating rejection.

Methods

Serum samples from heterotopic heart-transplanted LEW(RT-11) rats (either without immunosuppressive treatment or treated with methotrexate alone, rapamycin alone, or methotrexate and rapamycin combined) were analysed by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry. Protein profiles obtained using a weak cation exchange ProteinChip® CM-10 array were then analysed using ProteinChip® Software.

Results

Of 28 rejection-related proteins identified, isoelectric point and mass information from two potential candidate proteins matched information from the UniProtKB/Swiss-prot database, suggesting them to be complement component C3f fragment and complement component 4A (C4A, anaphylatoxin).

Conclusions

Proteomic analysis revealed 28 proteins as potential diagnostic markers of tissue rejection. Of these, 11 proteins may represent targets relating to the additive effects of methotrexate and rapamycin. Two protein peaks, with mass-to-charge ratios of 1950 Da and 8577 Da, may have potential for use in post-transplant diagnosis of rejection.
Chronic tension-type headache is associated with impaired motor learning
Authors: Vallence Ann-Maree , Smith Ashleigh , Tabor Abby , Rolan Paul E , Ridding Michael C
Published: April 2013

Background

Supraspinal activity-dependent neuroplasticity may be important in the transition from acute to chronic pain. We examined neuroplasticity in a cortical region not considered to be a primary component of the central pain matrix in chronic tension-type headache (CTTH) patients. We hypothesised that neuroplasticity would be exaggerated in CTTH patients compared to healthy controls, which might explain (in part) the development of chronic pain in these individuals.

Methods

Neuroplasticity was examined following a ballistic motor training task in CTTH patients and control subjects (CS). Changes in peak acceleration (motor learning) and motor-evoked potential (MEP) amplitude evoked by single-pulse transcranial magnetic stimulation were compared.

Results

CTTH patients showed significantly less motor learning on the training task than CS (mean acceleration increase 87% CTTH, 204% CS, p < .05), and CS but not CTTH patients showed a significant increased MEP amplitude following training (CS: F = 2.9, p < .05; CTTH: F = 1.6, p > .05).

Conclusions

These findings suggest a deficit in use-dependent neuroplasticity within networks responsible for task performance in CTTH patients which might reflect reciprocal influences between primary motor cortex and interconnected pain processing networks. These findings may help explain the positive effects of facilitatory non-invasive brain stimulation targeting motor areas on chronic pain and help elucidate the mechanisms mediating chronic pain.
The Munich ChronoType Questionnaire for Shift-Workers (MCTQShift)
Authors: Juda Myriam , Vetter Céline , Roenneberg Till
Published: April 2013

Sleep is systematically modulated by chronotype in day-workers. Therefore, investigations into how shift-work affects sleep, health, and cognition may provide more reliable insights if they consider individual circadian time (chronotype). The Munich ChronoType Questionnaire (MCTQ) is a useful tool for determining chronotype. It assesses chronotype based on sleep behavior, specifically on the local time of mid-sleep on free days corrected for sleep debt accumulated over the workweek (MSFsc). Because the original MCTQ addresses people working standard hours, we developed an extended version that accommodates shift-work (MCTQShift). We first present the validation of this new version with daily sleep logs ( n = 52) and actimetry ( n = 27). Next, we evaluated 371 MCTQShift entries of shift-workers (rotating through 8-h shifts starting at 0600 h, 1400 h, and 2200 h). Our results support experimental findings showing that sleep is difficult to initiate and to maintain under the constraints of shift-work. Sleep times are remarkably stable on free days (on average between midnight and 0900 h), so that chronotype of shift-workers can be assessed by means of MSF—similar to that of day-workers. Sleep times on free-days are, however, slightly influenced by the preceding shift (displacements <1 h), which are smallest after evening shifts. We therefore chose this shift-specific mid-sleep time (MSFE) to assess chronotype in shift-workers. The distribution of MSFE in our sample is identical to that of MSF in day-workers. We propose conversion algorithms for chronotyping shift-workers whose schedules do not include free days after evening shifts.
Chronotype Modulates Sleep Duration, Sleep Quality, and Social Jet Lag in Shift-Workers
Authors: Juda Myriam , Vetter Céline , Roenneberg Till
Published: April 2013

This study explores chronotype-dependent tolerance to the demands of working morning, evening, and night shifts in terms of social jet lag, sleep duration, and sleep disturbance. A total of 238 shift-workers were chronotyped with the Munich ChronoType Questionnaire for shift-workers (MCTQShift), which collects information about shift-dependent sleep duration and sleep timing. Additionally, 94 shift-workers also completed those items of the Sleep Questionnaire from the Standard Shift-Work Index (SSI) that assess sleep disturbances. Although all participants worked morning, evening, and night shifts, subsamples differed in rotation direction and speed. Sleep duration, social jet lag, and sleep disturbance were all significantly modulated by the interaction of chronotype and shift (mixed-model ANOVAs). Earlier chronotypes showed shortened sleep duration during night shifts, high social jet lag, as well as higher levels of sleep disturbance. A similar pattern was observed for later chronotypes during early shifts. Age itself only influenced sleep duration and quality per se, without showing interactions with shifts. We found that workers slept longer in fast, rotating shift schedules. Since chronotype changes with age, investigations on sleep behavior and circadian misalignment in shift-workers have to consider chronotype to fully understand interindividual and intraindividual variability, especially in view of the current demographic changes. Given the impact of sleep on health, our results stress the importance of chronotype both in understanding the effects of shift-work on sleep and in devising solutions to reduce shift-work–related health problems.
Predicted MicroRNAs for Mammalian Circadian Rhythms
Authors: Figueredo Diego de Siqueira , Barbosa Mayara Rodrigues , Gitaí Daniel Leite Góes , de Andrade Tiago Gomes
Published: April 2013

There is little evidence for the involvement of microRNAs (miRs) in the regulation of circadian rhythms, despite the potential relevance of these elements in the posttranscriptional regulation of the clock machinery. The present work aimed to identify miRs targeting circadian genes through a predictive analysis of conserved miRs in mammals. Besides 23 miRs previously associated with circadian rhythms, we found a number of interesting candidate genes, equally predicted by the 3 software programs used, including miR-9, miR-24, miR25, miR-26, miR-27, miR-29, miR-93, miR-211, miR-302, and miR-346. Moreover, several miRs are predicted to be regulated by circadian transcription factors, such as CLOCK/BMAL, DEC2, and REV-ERBalpha. Using real-time PCR we demonstrated that the selected candidate miR-27b showed a daily variation in human leukocytes. This study presents predicted feedback loops for mammalian molecular clock and the first description of an miR with in vivo daily variation in humans.