bluuebunny/crossref_metadata_2025 huggingface dataset:
Functional Consequences of Human Induced Pluripotent Stem Cell Therapy
Authors: Xiong Qiang , Ye Lei , Zhang Pengyuan , Lepley Michael , Tian Jinfeng , Li Jun , Zhang Liying , Swingen Cory , Vaughan J. Thomas , Kaufman Dan S. , Zhang Jianyi
Published: February 2013

Background—

The use of cells derived from human induced pluripotent stem cells as cellular therapy for myocardial injury has yet to be examined in a large-animal model.

Methods and Results—

Immunosuppressed Yorkshire pigs were assigned to 1 of 3 groups: A myocardial infarction group (MI group; distal left anterior descending coronary artery ligation and reperfusion; n=13); a cell-treatment group (MI with 4×10
6
vascular cells derived from human induced pluripotent stem cells administered via a fibrin patch; n=14); and a normal group (n=15). At 4 weeks, left ventricular structural and functional abnormalities were less pronounced in hearts in the cell-treated group than in MI hearts (
P
<0.05), and these improvements were accompanied by declines in scar size (10.4±1.6% versus 8.3±1.1%, MI versus cell-treatment group,
P
<0.05). The cell-treated group displayed a significant increase in vascular density and blood flow (0.83±0.11 and 1.05±0.13 mL·min
−1
·g
−1
, MI versus cell-treatment group,
P
<0.05) in the periscar border zone (BZ), which was accompanied by improvements in systolic thickening fractions (infarct zone, −10±7% versus 5±5%; BZ, 7±4% versus 23±6%;
P
<0.05). Transplantation of vascular cells derived from human induced pluripotent stem cells stimulated c-kit
+
cell recruitment to BZ and the rate of bromodeoxyuridine incorporation in both c-kit
+
cells and cardiomyocytes (
P
<0.05). Using a magnetic resonance spectroscopic saturation transfer technique, we found that the rate of ATP hydrolysis in BZ of MI hearts was severely reduced, and the severity of this reduction was linearly related to the severity of the elevations of wall stresses (
r
=0.82,
P
<0.05). This decline in BZ ATP utilization was markedly attenuated in the cell-treatment group.

Conclusions—

Transplantation of vascular cells derived from human induced pluripotent stem cells mobilized endogenous progenitor cells into the BZ, attenuated regional wall stress, stimulated neovascularization, and improved BZ perfusion, which in turn resulted in marked increases in BZ contractile function and ATP turnover rate.
Incidence and Associations of Poststroke Epilepsy
Authors: Graham Neil S.N. , Crichton Siobhan , Koutroumanidis Michael , Wolfe Charles D.A. , Rudd Anthony G.
Published: February 2013

Background and Purpose—

To describe the epidemiology and associations of poststroke epilepsy (PSE) because there is limited evidence to inform clinicians and guide future research.

Methods—

Data were collected from the population-based South London Stroke Register of first strokes in a multiethnic inner-city population with a maximum follow-up of 12 years. Self-completed forms and interviews notified study organizers of epilepsy diagnosis. Kaplan–Meier methods and Cox models were used to assess associations with sociodemographic factors, clinical features, stroke subtype, and severity markers.

Results—

Three thousand three-hundred ten patients with no history of epilepsy presented with first stroke between 1995 and 2007, with a mean follow-up of 3.8 years. Two-hundred thirteen subjects (6.4%) had development of PSE. PSE incidence at 3 months and 1, 5, and 10 years were estimated at 1.5%, 3.5%, 9.0%, and 12.4%, respectively. Sex, ethnicity, and socioeconomic status were not associations, but markers of cortical location, including dysphasia, visual neglect, and field defect, along with stroke severity indices at presentation, including low Glasgow Coma Scale, incontinence, or poor function on Barthel Index, were associated with PSE on univariate analysis. Young age was independently associated with PSE, affecting 10.7% of patients aged <65 years and 1.6% >85 years (
P
≤0.001) on 10-year estimates. Independent predictors of PSE also included visual neglect, dysphasia, and stroke subtype, particularly total anterior circulation infarcts. Dysarthria was associated with reduced incidence.

Conclusions—

PSE is common, with risk continuing to increase outside the acute phase. Young age, cortical location, larger lesions, and hemorrhagic lesions are independent predictors.
Motility at the Origin of Life: Its Characterization and a Model
Authors: Froese Tom , Virgo Nathaniel , Ikegami Takashi
Published: February 2013

Due to recent advances in synthetic biology and artificial life, the origin of life is currently a hot topic of research. We review the literature and argue that the two traditionally competing replicator-first and metabolism-first approaches are merging into one integrated theory of individuation and evolution. We contribute to the maturation of this more inclusive approach by highlighting some problematic assumptions that still lead to an ximpoverished conception of the phenomenon of life. In particular, we argue that the new consensus has so far failed to consider the relevance of intermediate time scales. We propose that an adequate theory of life must account for the fact that all living beings are situated in at least four distinct time scales, which are typically associated with metabolism, motility, development, and evolution. In this view, self-movement, adaptive behavior, and morphological changes could have already been present at the origin of life. In order to illustrate this possibility, we analyze a minimal model of lifelike phenomena, namely, of precarious, individuated, dissipative structures that can be found in simple reaction-diffusion systems. Based on our analysis, we suggest that processes on intermediate time scales could have already been operative in prebiotic systems. They may have facilitated and constrained changes occurring in the faster- and slower-paced time scales of chemical self-individuation and evolution by natural selection, respectively.
Evolutionary Acquisition of a Mortal Genetic Program: The Origin of an Altruistic Gene
Authors: Oohashi Tsutomu , Maekawa Tadao , Ueno Osamu , Kawai Norie , Nishina Emi , Honda Manabu
Published: February 2013

As part of our research on programmed self-decomposition, we formed the hypothesis that originally immortal terrestrial organisms evolve into ones that are programmed for autonomous death. We then conducted evolutionary simulation experiments in which we examined this hypothesis using an artificial ecosystem that we designed to resemble a terrestrial ecosystem endowed with artificial chemistry. Notable results corroborating our hypothesis were obtained, which showed that mortal organisms emerged from indigenous immortal organisms through mutation; such mortal organisms survived and left behind offspring, albeit very rarely, and, having survived, surpassed immortal organisms without exception. In this article, we report the details of the above findings and also discuss a background framework we previously constructed for approaching altruism.
Robustness, Evolvability, and the Logic of Genetic Regulation
Authors: Payne Joshua L. , Moore Jason H. , Wagner Andreas
Published: February 2013

In gene regulatory circuits, the expression of individual genes is commonly modulated by a set of regulating gene products, which bind to a gene's cis-regulatory region. This region encodes an input-output function, referred to as signal-integration logic, that maps a specific combination of regulatory signals (inputs) to a particular expression state (output) of a gene. The space of all possible signal-integration functions is vast and the mapping from input to output is many-to-one: For the same set of inputs, many functions (genotypes) yield the same expression output (phenotype). Here, we exhaustively enumerate the set of signal-integration functions that yield identical gene expression patterns within a computational model of gene regulatory circuits. Our goal is to characterize the relationship between robustness and evolvability in the signal-integration space of regulatory circuits, and to understand how these properties vary between the genotypic and phenotypic scales. Among other results, we find that the distributions of genotypic robustness are skewed, so that the majority of signal-integration functions are robust to perturbation. We show that the connected set of genotypes that make up a given phenotype are constrained to specific regions of the space of all possible signal-integration functions, but that as the distance between genotypes increases, so does their capacity for unique innovations. In addition, we find that robust phenotypes are (i) evolvable, (ii) easily identified by random mutation, and (iii) mutationally biased toward other robust phenotypes. We explore the implications of these latter observations for mutation-based evolution by conducting random walks between randomly chosen source and target phenotypes. We demonstrate that the time required to identify the target phenotype is independent of the properties of the source phenotype.
Many Hands Make Light Work: Further Studies in Group Evolution
Authors: Tomko Nicholas , Harvey Inman , Virgo Nathaniel , Philippides Andrew
Published: February 2013

When niching or speciation is required to perform a task that has several different component parts, standard genetic algorithms (GAs) struggle. They tend to evaluate and select all individuals on the same part of the task, which leads to genetic convergence within the population. The goal of evolutionary niching methods is to enforce diversity in the population so that this genetic convergence is avoided. One drawback with some of these niching methods is that they require a priori knowledge or assumptions about the specific fitness landscape in order to work; another is that many such methods are not set up to work on cooperative tasks where fitness is only relevant at the group level. Here we address these problems by presenting the group GA, described earlier by the authors, which is a group-based evolutionary algorithm that can lead to emergent niching. After demonstrating the group GA on an immune system matching task, we extend the previous work and present two modified versions where the number of niches does not need to be specified ahead of time. In the random-group-size GA, the number of niches is varied randomly during evolution, and in the evolved-group-size GA the number of niches is optimized by evolution. This provides a framework in which we can evolve groups of individuals to collectively perform tasks with minimal a priori knowledge of how many subtasks there are or how they should be shared out.
Changes in Animal Welfare Views in New Zealand: Responding to Global Change
Authors: Loveridge Alison
Published: February 2013

Abstract

Consumer action is leading to increasing debate over on-farm activities in New Zealand. Both animal welfare activists and government organizations frequently refer to the importance of welfare standards in order to secure overseas markets, as well as in response to local concerns. This article explores rural and urban people’s views of welfare of animals kept on farms for commercial purposes in response to a 2008 survey commissioned by the Ministry of Agriculture and Forestry. It compares and contrasts these recent findings with those of an earlier (1994) survey, to demonstrate how understanding of—and the impetus for—changing farm practices have developed. The article also looks at the global context of the animal welfare issue and discusses how overseas trends impact the New Zealand situation. The view that animal welfare is purely about physical well-being is among those challenged at home and abroad, and farmers are now forced to defend and amend industry standards.
“I Didn’t Feel Right About Animal Dissection”: Dissection Objectors Share Their Science Class Experiences
Authors: Oakley Jan
Published: February 2013

Abstract

This paper highlights the voices and experiences of individuals who objected to animal dissection in their high school science and biology classes. The data were collected via online surveys (n = 311), and 8 of these participants took part in more in-depth telephone interviews. Participants were former students from Ontario, Canada, who discussed their experiences with animal dissection in general, and objection to dissection in particular, if applicable. The findings reveal that students who expressed objection to dissection experienced a range of teacher responses, including pressure to participate, the request to join another group of students and watch, the choice to use a dissection alternative, warnings of compromised grades, and other responses. The study points to the importance of choice policies to ensure that dissection alternatives are available in classrooms. In this way, students can select among different options of how they would like to learn, and teachers can be prepared to accommodate those who choose not to dissect.
Validation of Environment Canada and NOAA UV Index Forecasts with Brewer Measurements from Canada
Authors: He Huixia , Fioletov Vitali E. , Tarasick David W. , Mathews Thomas W. , Long Craig
Published: February 2013

Ground-based ultraviolet (UV) irradiance measurements by Brewer spectrophotometers at 10 sites across Canada are compared with UV index forecasts for the same locations from Environment Canada (EC) and NOAA. For the EC forecast validation, summertime (May–August) data for the period from 1996 to 2009 are used. Comparison with NOAA forecasts is made for the more limited period of May–August 2006 and 2007. Several statistical measures are used, including the mean and the standard deviation of differences, correlation coefficients, and the probability of detection and false-alarm rate for prediction of high (UV index of 6 or above) values. For most conditions, only modest differences are found between the two forecasting systems; that is, UV index forecasts reported in the United States and Canada for Canadian sites are compatible. In general, the physically based NOAA system, which started operation in 2005, performs better than the semiempirical EC model, developed in the mid-1990s. The difference in model performance is not large under clear-sky and light-cloud conditions, but the EC model underperforms relative to the NOAA model under heavy-cloud and rainy conditions. Both the EC and the NOAA forecast models tend to overestimate UV under clear-sky and light-cloud conditions. Under heavy-cloud and rainy conditions, the EC model underestimates UV values, with about 30% of all forecasts under these conditions being 2 or more units below observations. NOAA forecasts tend to overestimate UV index values under these conditions.
A Unified Model for Moist Convective Boundary Layers Based on a Stochastic Eddy-Diffusivity/Mass-Flux Parameterization
Authors: Sušelj Kay , Teixeira João , Chung Daniel
Published: February 2013

A single-column model (SCM) is developed for representing moist convective boundary layers. The key component of the SCM is the parameterization of subgrid-scale vertical mixing, which is based on a stochastic eddy-diffusivity/mass-flux (EDMF) approach. In the EDMF framework, turbulent fluxes are calculated as a sum of the turbulent kinetic energy–based eddy-diffusivity component and a mass-flux component. The mass flux is modeled as a fixed number of steady-state plumes. The main challenge of the mass-flux model is to properly represent cumulus clouds, which are modeled as moist plumes. The solutions have to account for a realistic representation of condensation within the plumes and of lateral entrainment into the plumes. At the level of mean condensation within the updraft, the joint pdf of moist conserved variables and vertical velocity is used to estimate the proportion of dry and moist plumes and is sampled in a Monte Carlo way creating a predefined number of plumes. The lateral entrainment rate is modeled as a stochastic process resulting in a realistic decrease of the convective cloudiness with height above cloud base. In addition to the EDMF scheme, the following processes are included in the SCM: a pdf-based parameterization of subgrid-scale condensation, a simple longwave radiation, and one-dimensional dynamics. Note that in this approach there are two distinct pdfs, one representing the variability of updraft properties and the other one the variability of thermodynamic properties of the surrounding environment. The authors show that the model is able to capture the essential features of moist boundary layers, ranging from stratocumulus to shallow-cumulus regimes. Detailed comparisons, which include pdfs, profiles, and integrated budgets with the Barbados Oceanographic and Meteorological Experiment (BOMEX), Dynamics and Chemistry of Marine Stratocumulus (DYCOMS), and steady-state large-eddy simulation (LES) cases, are discussed to confirm the quality of the present approach.
Interhemispheric Temperature Asymmetry over the Twentieth Century and in Future Projections
Authors: Friedman Andrew R. , Hwang Yen-Ting , Chiang John C. H. , Frierson Dargan M. W.
Published: February 2013

The temperature contrast between the Northern and Southern Hemispheres—the interhemispheric temperature asymmetry (ITA)—is an emerging indicator of global climate change, potentially relevant to the Hadley circulation and tropical rainfall. The authors examine the ITA in historical observations and in phases 3 and 5 of the Coupled Model Intercomparison Project (CMIP3 and CMIP5) simulations. The observed annual-mean ITA (north minus south) has varied within a 0.8°C range and features a significant positive trend since 1980. The CMIP multimodel ensembles simulate this trend, with a stronger and more realistic signal in CMIP5. Both ensembles project a continued increase in the ITA over the twenty-first century, well outside the twentieth-century range. The authors mainly attribute this increase to the uneven spatial impacts of greenhouse forcing, which result in amplified warming in the Arctic and northern landmasses. The CMIP5 specific-forcing simulations indicate that, before 1980, the greenhouse-forced ITA trend was primarily countered by anthropogenic aerosols. The authors also identify an abrupt decrease in the observed ITA in the late 1960s, which is generally not present in the CMIP simulations; it suggests that the observed drop was caused by internal variability. The difference in the strengths of the northern and southern Hadley cells covaries with the ITA in the CMIP5 simulations, in accordance with previous findings; the authors also find an association with the hemispheric asymmetry in tropical rainfall. These relationships imply a northward shift in tropical rainfall with increasing ITA in the twenty-first century, though this result is difficult to separate from the response to global-mean temperature change.
MJO and Convectively Coupled Equatorial Waves Simulated by CMIP5 Climate Models
Authors: Hung Meng-Pai , Lin Jia-Lin , Wang Wanqiu , Kim Daehyun , Shinoda Toshiaki , Weaver Scott J.
Published: February 2013

This study evaluates the simulation of the Madden–Julian oscillation (MJO) and convectively coupled equatorial waves (CCEWs) in 20 models from the Coupled Model Intercomparison Project (CMIP) phase 5 (CMIP5) in the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5) and compares the results with the simulation of CMIP phase 3 (CMIP3) models in the IPCC Fourth Assessment Report (AR4). The results show that the CMIP5 models exhibit an overall improvement over the CMIP3 models in the simulation of tropical intraseasonal variability, especially the MJO and several CCEWs. The CMIP5 models generally produce larger total intraseasonal (2–128 day) variance of precipitation than the CMIP3 models, as well as larger variances of Kelvin, equatorial Rossby (ER), and eastward inertio-gravity (EIG) waves. Nearly all models have signals of the CCEWs, with Kelvin and mixed Rossby–gravity (MRG) and EIG waves being especially prominent. The phase speeds, as scaled to equivalent depths, are close to the observed value in 10 of the 20 models, suggesting that these models produce sufficient reduction in their effective static stability by diabatic heating. The CMIP5 models generally produce larger MJO variance than the CMIP3 models, as well as a more realistic ratio between the variance of the eastward MJO and that of its westward counterpart. About one-third of the CMIP5 models generate the spectral peak of MJO precipitation between 30 and 70 days; however, the model MJO period tends to be longer than observations as part of an overreddened spectrum, which in turn is associated with too strong persistence of equatorial precipitation. Only one of the 20 models is able to simulate a realistic eastward propagation of the MJO.
Twenty-First-Century Compatible CO2 Emissions and Airborne Fraction Simulated by CMIP5 Earth System Models under Four Representative Concentration Pathways
Authors: Jones Chris , Robertson Eddy , Arora Vivek , Friedlingstein Pierre , Shevliakova Elena , Bopp Laurent , Brovkin Victor , Hajima Tomohiro , Kato Etsushi , Kawamiya Michio , Liddicoat Spencer , Lindsay Keith , Reick Christian H. , Roelandt Caroline , Segschneider Joachim , Tjiputra Jerry
Published: February 2013

The carbon cycle is a crucial Earth system component affecting climate and atmospheric composition. The response of natural carbon uptake to CO2 and climate change will determine anthropogenic emissions compatible with a target CO2 pathway. For phase 5 of the Coupled Model Intercomparison Project (CMIP5), four future representative concentration pathways (RCPs) have been generated by integrated assessment models (IAMs) and used as scenarios by state-of-the-art climate models, enabling quantification of compatible carbon emissions for the four scenarios by complex, process-based models. Here, the authors present results from 15 such Earth system GCMs for future changes in land and ocean carbon storage and the implications for anthropogenic emissions. The results are consistent with the underlying scenarios but show substantial model spread. Uncertainty in land carbon uptake due to differences among models is comparable with the spread across scenarios. Model estimates of historical fossil-fuel emissions agree well with reconstructions, and future projections for representative concentration pathway 2.6 (RCP2.6) and RCP4.5 are consistent with the IAMs. For high-end scenarios (RCP6.0 and RCP8.5), GCMs simulate smaller compatible emissions than the IAMs, indicating a larger climate–carbon cycle feedback in the GCMs in these scenarios. For the RCP2.6 mitigation scenario, an average reduction of 50% in emissions by 2050 from 1990 levels is required but with very large model spread (14%–96%). The models also disagree on both the requirement for sustained negative emissions to achieve the RCP2.6 CO2 concentration and the success of this scenario to restrict global warming below 2°C. All models agree that the future airborne fraction depends strongly on the emissions profile with higher airborne fraction for higher emissions scenarios.
Enterprise Policy and the Metagovernance of Firm Capabilities
Authors: Parker Rachel , Hine Damian
Published: February 2013

The underlying logic of enterprise policy is that there are impediments to change in economic systems that can be traced to the path-dependent behaviors of economic actors that prevent them from exploring new knowledge and new ways of doing things. Enterprise policy involves firm-level interventions delivered by distributed networks of business advisors coordinated by knowledge intermediaries. These metagovernance arrangements are able to disrupt the path-dependent behaviors of organizations. The logic and benefits of enterprise policy are explored through reference to public administration, strategic management and evolutionary theory, and three case studies.
Explaining Mobilization and Performance of Collaborations in Routine Emergency Management
Authors: Nohrstedt Daniel
Published: February 2013

Researchers as well as practitioners often elevate collaborative governance as a necessary condition for effective responses to extreme events. This research has a dominating focus on large-scale catastrophes and disasters, whereas little attention is devoted to less serious emergencies. Another void concerns performance measurement. Addressing these gaps, this study investigates plausible explanations for collaborative activity and outcomes in response to extreme winter conditions in Sweden. Analysis of a survey of Swedish public managers suggests that, in this case, collaborative action is associated with preparatory actions and disruptions affecting other organizations. The analysis generates conflicting findings regarding underlying explanations for collaborative outcomes.
A Pilot Study to Increase Chewing in Children With Feeding Disorders
Authors: Volkert Valerie M. , Piazza Cathleen C. , Vaz Petula C. M. , Frese Jana
Published: February 2013

Children with feeding disorders often display chewing deficits. Unfortunately, there is a paucity of research examining procedures to increase or teach chewing to children with feeding disorders. The few studies on this topic have utilized multicomponent treatments typically involving a shaping procedure. In addition, to our knowledge, studies on chewing have not yet incorporated a product measure of chewing (whether the food is broken down enough to swallow after chewing), which we have termed mastication. In the current investigation, we evaluated relatively simple treatments to increase chewing with two children with a feeding disorder who were not chewing at clinically acceptable levels after treatment with nonremoval of the spoon. We also developed a product measure of chewing. In Study 1, we used a least-to-most prompting plus praise procedure to increase chews per bite in a typically developing child with a feeding disorder. We then used the results of Study 1 to refine treatment and develop our mastication measure for Study 2. In Study 2, we implemented a descriptive verbal prompt and praise procedure to increase chews per bite and percentage of mastication with one child with developmental delays and a feeding disorder.
Immunohistochemical Expression of Melanocytic Antigen PNL2, Melan A, S100, and PGP 9.5 in Equine Melanocytic Neoplasms
Authors: Ramos-Vara J. A. , Frank C. B. , DuSold D. , Miller M. A.
Published: February 2013

The immunoreactivity of PNL2, Melan A, and protein gene product (PGP) 9.5 was compared with that of S100 protein in 50 formalin-fixed, paraffin-embedded equine melanocytic neoplasms. PNL2, PGP 9.5, and S100 protein were detected in all 50 neoplasms; none expressed Melan A. PNL2 was not expressed in 62 nonmelanocytic tumors (equine sarcoids, schwannomas, carcinomas, sarcomas, endocrine tumors, sex-cord stromal tumors, germ cell tumors, and leukocytic tumors) or in normal tissues other than epidermis. In summary, antibody PNL2 is a sensitive marker of equine melanocytic neoplasms and is more specific than S100 protein or PGP 9.5. In contrast, the monoclonal antibody to Melan A did not react with any of the equine melanomas.
Infection of Cattle With Cryptosporidium parvum
Authors: Li S. , Li W. , Yang Z. , Song S. , Yang J. , Gong P. , Zhang W. , Liu K. , Li J. , Zhang G. , Zhang X.
Published: February 2013

Mast cells might play an important role as the major effector cells in the immune response against Cryptosporidium parvum. C. parvum is a protozoan parasite that causes cryptosporidiosis in animals and humans worldwide. To investigate the interaction between C. parvum and mast cells during infection, nine 3-day-old male calves were orally challenged with 106 oocysts of C. parvum per calf. The distribution of mast cells in the mucosa of the small intestine was analyzed by toluidine blue staining. The concentrations of histamine and the cytokines interferon-γ, interleukin-4, interleukin-2, and interleukin-12 were measured in the serum, and the histamine levels were also determined from the intestinal contents. The following clinical signs were monitored: nausea, watery diarrhea, dehydration, and weight loss. Oocysts were shed in the feces during the infection period. C. parvum infection induced an increase in mast cell numbers in the mucosa of the small intestine in distinct temporal and spatial patterns. Infection with C. parvum can induce mastocytosis in the entire small intestinal mucosa in immune-competent calves, and the presence of the parasites influences the distribution profile of the mast cells.
Analysis and testing of ultrathin shell 2 m diameter reflector demonstrator
Authors: Soykasap Ömer , Karakaya Şükrü
Published: February 2013

Ultra-thin shell foldable and self-deploying composite reflectors are being developed for space antennas to meet low cost, low mass and high surface accuracy. For Ku-band missions, a full-scale offset parabolic reflector antenna is designed by considering different concepts of monolithic and nonmonolithic structures, different stiffening schemes, manufacturing ease, and lower cost. The resulting reflector is based on stiffened spring back reflector concept but it provides much simpler design, significantly lower mass and lower cost. It is a simple monolithic structure and consists of a reflector surface and a flat skirt. The skirt is an integral part of the reflector and is used to stiffen the reflector. The full-size version is an offset parabolic reflector with a diameter of 6 m, a focal length of 4.8 m, and an offset of 0.3 m. In order to demonstrate the concept, 1/3-scaled version is designed, manufactured, and tested. Experiments of the demonstrator are conducted for quasi-static folding, dynamic deployment behavior, stiffness measurements, modal analysis, and surface accuracy in deployed configuration; the experimental results are compared with the results of finite elements solutions where applicable.
Extending the Hours of Operation of Alcohol Serving Establishments
Authors: Chamlin Mitchell B. , Scott Sarah E.
Published: February 2013

On May 11, 2009, the City of San Marcos, Texas adopted an ordinance that allowed local bars to extend their hours of operation from midnight until 2 a.m. The objective of this initiative, which went into effect on June 4, 2009, was to minimize the problems that arise from the consumption of alcohol. The present investigation uses interrupted time series autoregressive integrated moving average [ARIMA]) modeling techniques to analyze weekly data to assess the impact of the ordinance, along with a limited increase in patrol strength in the downtown district, on the number of calls for service involving verbal disturbances, physical disturbances, public intoxication, and driving under the influence of alcohol. Overall, the interrupted time series analyses indicate that neither the city council’s nor the police department’s strategies for mitigating some of the negative consequences of the consumption of alcoholic beverages in bars and taverns were successful. The implications of these findings for lessening alcohol-related conflicts between bar patrons and other residents of the community are discussed.
Knowledge Governance
Authors: Antonelli Cristiano
Published: February 2013

Building on the Schumpeterian and the Marshallian legacies, this article elaborates a model of endogenous growth. It provides a systemic explanation for the levels and the rates of total factor productivity growth. The generation of technological knowledge consists in the recombination of existing bits of heterogeneous technological knowledge that is necessarily possessed by a myriad of agents. As such, much technological knowledge is external to each agent and yet an essential input. In this context, knowledge governance mechanisms play a key role in the identification, recollection, and provision of the specific items of necessary technological knowledge, external to each agent. Effective knowledge governance mechanisms engender pecuniary knowledge externalities that take place, mainly at the regional level, when and where existing units of external knowledge can be identified, accessed, unbundled, and used—again—at costs that are below equilibrium ones for the recombinant generation of new technological knowledge.
Wave energy converter of inverse pendulum with double action power take off
Authors: Zhang Dahai , Li Wei , Ying You , Zhao Haitao , Lin Yonggang , Bao Jingwei
Published: February 2013

This article describes a double action hydraulic power take off for a wave energy converter of inverse pendulum. The power take off converts slow irregular reciprocating wave motions to relatively smooth, fast rotation of an electrical generator. The design of the double action power take off and its control are critical to the magnitude and the continuity of the generated power. The interaction between the power take off behavior and the wave energy converter’s hydrodynamic characteristics is complex, therefore a time domain simulation study is presented in which both parts are included. The power take off is modeled using AMESim®, and the hydrodynamic equations are implemented in MATLAB®; simulation is used to predict the behavior of the complete system. The simulation results show that the design of the double action hydraulic power take off for wave energy converter of inverse pendulum is entirely feasibility and its superiority has been verified by the preliminary experiments, especially compared with the existing single action power take off system.
Investigation of the contact force distribution and dynamic behaviour of an automobile windshield wiper blade system
Authors: Lee Sang Hwan , Kim Young Heon , Sung Jisu , Shin Kum Cheol , Oh Je Hoon
Published: February 2013

The structural behaviour of a windshield wiper system and the dynamic behaviour of the wiper rubber blade are investigated using finite element analysis. Non-linear contact analysis was performed to examine the influences of the structural design variables such as the curvature of the primary beam, the thickness of the yoke, the rotational angle of the yoke and the thickness of the steel beam on the distribution of the contact force along the blade length, and the effects of the vertical load and the coefficient of friction on the vibrational behaviour of the blade were investigated using transient dynamic analysis. Experimental validation was conducted by measuring the contact force distribution and the vibrational behaviour of the rubber blade. The experimental data and the simulated results show good agreement. The contact force distribution is sensitive to changes in the primary beam’s curvature, the yoke’s rotational angle and the steel beam’s thickness. The vertical load and the coefficient of friction both have significant influences on the vibrational behaviour of the rubber blade. It is found that the proper combination of the variables investigated allows a more uniform contact force distribution and less vibration and thereby improves the performance of the wiper blade. These analyses demonstrate the variables that influence the wiper blade behaviour and should provide key insight into means for improving the wiper performance.
Impaired phagocytosis and susceptibility to infection in pediatric-onset systemic lupus erythematosus
Authors: Wu S-A , Yeh K-W , Lee W-I , Yao T-C , Kuo M-L , Huang B , Huang J-L
Published: February 2013

Objectives

Impaired function of polymorphonuclear cells (PMNs) in systemic lupus erythematosus (SLE) leads to severe gram-positive and gram-negative bacterial infection, and to major morbidity and mortality. Few studies have focused on the association of impaired function of PMNs and SLE patients’ susceptibility to infection. This study aimed to analyze function of PMNs in peroxidase production, chemotaxis, and phagocytosis in pediatric-onset SLE with severe infection.

Methods

This study compared function of PMNs among pediatric-onset SLE patients with and without histories of severe infection and in normal control subjects. Human peripheral blood PMNs were isolated from patients and controls. Function of PMNs was measured by analyzing peroxidase, chemotaxis, and phagocytic activities. Different disease activity and severity, and drug use in newly diagnosed SLE patients were also compared.

Results

In total, 34 SLE patients (12 patients with severe infection, 22 patients without infection) and 25 healthy controls were analyzed. There were no differences in function of PMNs between SLE patients with or without severe infection. Regardless of infection status, medication, and disease activity, SLE patients had impaired phagocytic ability against Salmonella-specific lipopolysaccharides (LPS) compared with normal controls ( p < 0.01). The use of immunosuppressants did not influence phagocytic ability against Salmonella-derived LPS.

Conclusions

Immunosuppressant agents do not influence phagocytic ability against Salmonella in SLE subjects. Impaired phagocytosis against Salmonella is prominent in pediatric-onset SLE subjects, which may result in the high prevalence of Salmonella infection. There is no deficiency of peroxidase production and chemotaxis activity among SLE subjects.
Biomechanical Analysis of the Calcaneocuboid Joint Pressure After Sequential Lengthening of the Lateral Column
Authors: Xia Jiang , Zhang Peng , Yang Yun-Feng , Zhou Jia-Qian , Li Qian-Ming , Yu Guang-Rong
Published: February 2013

Background:

Lengthening of the lateral column by means of the Evans osteotomy is commonly used for reconstruction of adult and pediatric flatfoot. However, some reports have shown that the Evans osteotomy is linked with increased calcaneocuboid joint pressures and an increased risk of arthritis in the joint. The purpose of this study was to measure the pressure across the calcaneocuboid joint and demonstrate the changing trends of the pressure within the calcaneocuboid joint after sequential lengthening of the lateral column.

Methods:

Six cadaver specimens were physiologically loaded and the peak pressure of the calcaneocuboid joint was measured under the following conditions: (1) normal foot, (2) flatfoot, and (3) sequential lengthening of the lateral column by means of the Evans procedure (from 4 mm to 12 mm, in 2 mm increments).

Results:

Peak pressures across the joint increased significantly from baseline in the flatfoot ( P < .05). In the corrected foot, with the increment of the graft, the peak pressure decreased initially and then increased. The pressure reached its minimum value (11.04 ± 1.15 kg/cm2) with 8 mm lengthening of the lateral column. The differences were significant compared to the flatfoot ( P < .05) and corrected foot with the other sizes of grafts ( P < .05), but differences were not significant compared to the intact foot ( P = .143).

Conclusions:

Lateral column lengthening within a certain extent will decrease the pressure in calcaneocuboid joint with a flatfoot deformity.

Clinical Relevance:

Performing the procedure with an 8 mm lengthening may reduce the risk of the secondary calcaneocuboid osteoarthritis.
Subtalar Arthrodesis Alignment
Authors: Jastifer James R. , Gustafson Peter A. , Gorman Robert R.
Published: February 2013

Background:

The position, axis, and control of each lower extremity joint intimately affect adjacent joint function as well as whole-limb performance. A review of the literature finds little describing the biomechanics of subtalar arthrodesis and the effect on ankle biomechanics. The purpose of the current study was to establish this effect on sagittal plane ankle biomechanics.

Methods:

A study was performed using a 3-dimensional, validated, computational model of the lower extremity. A subtalar arthrodesis was simulated from 20 degrees of varus to 20 degrees of valgus. At each arthrodesis position, the ankle dorsiflexor and plantarflexor muscles’ fiber force, moment arm, and moments were calculated throughout a physiologic range of motion.

Results:

Throughout ankle range of motion, plantarflexion and dorsiflexion strength varied with subtalar arthrodesis position. When the ankle joint was in neutral sagittal alignment, plantarflexion strength was maximized in 10 degrees of subtalar valgus, and strength varied by a maximum of 2.6% from the peak 221 Nm. In a similar manner, with the ankle joint in neutral position, dorsiflexion strength was maximized with a subtalar joint arthrodesis in 5 degrees of valgus, and strength varied by a maximum of 7.5% from the peak 46.8 Nm. The change in strength was due to affected muscle fiber force generating capacities and muscle moment arms.

Conclusion:

The significance of this study is that subtalar arthrodesis in a position of 5 to 10 degrees of subtalar valgus has a biomechanical advantage.

Clinical Relevance:

This supports previous clinical outcome studies and offers a biomechanical rationale for their generally favorable outcomes.
Gutter Impingement After Total Ankle Arthroplasty
Authors: Schuberth John M. , Babu Nina S. , Richey Johanna M. , Christensen Jeffrey C.
Published: February 2013

Background:

Symptomatic gutter impingement after ankle arthroplasty has been reported with various designs. However, the incidence and origin of impingement have not been fully elucidated. Furthermore, the outcome of patients following gutter debridement has not been reported.

Methods:

A review of 489 total ankle replacements was performed to calculate the incidence of symptomatic gutter impingement in 4 different devices and between the presenting causes of arthritis. The incidence of gutter impingement was determined for patients with and without preemptive gutter resection at the time of implantation. The functional outcome of 30 of the 34 patients who had subsequent gutter debridement was determined with 3 different outcome instruments.

Results:

Symptomatic gutter disease occurred in 34 of 489 cases (7%) followed for a minimum of 1 year (range, 1-12 years). There was a 2% incidence of gutter disease in the 194 ankles that had prophylactic gutter resection at the time of implantation and a 7% incidence in the 295 ankles that did not have gutter resection at the time of implantation. When the ankle treated with an Agility (DePuy Orthopaedics, Inc, Warsaw, IN) device was excluded, there was a 2% and an 18% incidence of gutter disease in the 2 groups, respectively ( P < .05). There was no difference in the incidence of gutter disease between the various implants and origins of ankle arthritis. Postoperative outcomes were favorable in the 27 patients who did not have another procedure after the initial gutter debridement. Seven patients (21%) required reoperation.

Conclusion:

Prophylactic gutter resection should be considered at the time of implantation to reduce the incidence of postoperative symptoms. Although most patients had favorable outcomes following gutter debridement, there was a high reoperation rate.

Level of Evidence:

Level III, retrospective comparative series.
Assessing Accuracy of Sustentaculum Screw Placement During Calcaneal Fixation
Authors: Gitajn I. Leah , Toussaint Rull James , Kwon John Y.
Published: February 2013

Background:

The aim of this study was to determine the ability of the Harris heel view to confirm placement of the sustentacular screw during calcaneal fixation.

Methods:

A 4.0 cancellous screw was placed in a cadaveric specimen, from lateral to medial in 5 configurations: (1) within the sustentaculum, (2) misdirected inferiorly to sustentaculum, (3) misdirected superiorly to sustentaculum, (4) misdirected anteriorly to sustentaculum, and (5) misdirected posteriorly to sustentaculum. Harris heel views were obtained at 5 angulations and were analyzed to determine screw placement.

Results:

A screw placed anatomically was radiographically confirmed by the Harris heel view to be within the sustentaculum in all views. An inferiorly misdirected screw appeared radiographically within the sustentaculum at 30, 40 and 50 degrees but was confirmed misplaced on the 10- and 20-degree views. A posteriorly misdirected screw was confirmed misplaced on all 5 views. An anteriorly misdirected screw appeared radiographically within the sustentaculum on the 10-degree view but was confirmed misplaced on all other views. A superiorly misdirected screw was confirmed misplaced on all views.

Conclusions:

Clinicians should be aware that several specific axial heel views are required to verify placement of the sustentacular screw. An inferiorly misdirected screw will appear to be within the sustentaculum with the standard Harris heel view.

Clinical Relevance:

Heel views should be obtained from a range of 10 to 50 degrees to confirm accurate placement of the sustentacular screw.
Changes in Ankle Range of Motion and Muscle Strength in Habitual Wearers of High-Heeled Shoes
Authors: Kim Yushin , Lim Jong-Min , Yoon BumChul
Published: February 2013

Background:

Although cross-sectional biomechanical studies have reported that wearing high-heeled shoes can change the musculoskeletal system of the lower extremities, the long-term effects of wearing such shoes on the ankle remain unknown. The aim of this study was to reveal changes in ankle range of motion and muscle strength in habitual wearers of high-heeled shoes and to provide information for clinicians undertaking functional evaluations of the ankles of such patients.

Methods:

Habitual wearers of high-heeled shoes (n = 10; age, 23.9 ± 2.7 years) and wearers of flat shoes (n = 10; age, 23.8 ± 2.1 years) were selectively recruited, and the range of motion, maximal voluntary isometric force, and concentric contraction power of their ankles were measured.

Results:

Wearers of high-heeled shoes showed increased ankle range of motion on plantarflexion at 25 degrees and inversion at 10 degrees compared to flat shoe wearers ( P < .05) but decreased dorsiflexion (about 17 degrees) and eversion (13 degrees; P < .05). Concentric contraction power in ankle eversion was also 2 times higher in wearers of high-heeled shoes ( P < .05).

Conclusions:

These subjects had functional deformity of the ankle in a supinated direction and increased eversion power.

Clinical Relevance:

We cautiously recommend that habitual wearers of high-heeled shoes (those who walk in such shoes for more than 5 hours more than 6 times a week) undertake intensive ankle stretching exercises in the direction of dorsiflexion as well as eversion.
Effect investigation of relative humidity and temperature on multi-layer corrugated sandwich structures
Authors: Dongmei Wang , Huxiang Gong , Ziyou Bai
Published: February 2013

The mechanical properties of multi-layer corrugated sandwich structure are investigated in this paper. The mathematical model in which the structure factors and temperature and relative humidity are concerned is developed through the cooperation of theories and experiments. Then the model is normalized by the elastic modulus of the medium under controlled condition, thus this model can be used to predict the effect of various temperature and relative humidities on the plateau stress of multi-layer corrugated sandwich structure under flatwise compression. Comparisons of the predictions and experiments are made in order to examine the accuracy of the model, and a good correlation is obtained in view of the experimental error. The proposed model can be applied to the practical material selection and optimal design of corrugated sandwiches. Meanwhile, the proposed model might provide valuable information for the investigation of different materials with corrugated sandwich structure.