bluuebunny/crossref_metadata_2025 huggingface dataset:
Human hypertrophic scar‐like nude mouse model: Characterization of the molecular and cellular biology of the scar process
Authors: Wang JianFei , Ding Jie , Jiao Haiyan , Honardoust Dariush , Momtazi Moein , Shankowsky Heather A. , Tredget Edward E.
Published: March 2011

Hypertrophic scar (HTS) following thermal injury and other forms of trauma is a dermal fibroproliferative disorder that leads to considerable morbidity. Because of the lack of an ideal animal model, research is difficult. We have established an HTS model that involves transplanting human split‐thickness skin graft (STSG) or full‐thickness skin graft (FTSG) onto the backs of nude mice. The animals developed raised, firm, and reddish scars 2 months following transplantation. Histology and micromeasurement indicate raised, thickened engrafted skin with STSG and FTSG. In contrast, thickening was not observed with full‐thickness rat skin grafts used as controls. Masson's trichrome staining demonstrates increased accumulations of collagen fibrils in the dermis in both scars grafted with STSG and FTSG. Staining cells with toludine blue and an antibody for F4/80 showed an increase in the infiltration of mast cells and macrophages. Quantification of fibrocytes reveals increased fibrocytes. Moreover, STSG grafted skin had significantly more macrophages, mast cells, and fibrocytes than FTSG. Real‐time polymerase chain reaction analysis showed significantly elevated mRNA levels for type I collagen, transforming growth factor‐β, connective tissue growth factor and heat shock protein 47 in both types of engrafted skin. These data demonstrate that human skin grafted onto nude mice develops red raised and thickened scars having intrinsic properties that closely resemble HTS formation as seen in humans. Interestingly, STSG developed more scar than FTSG. Furthermore, inflammatory cells and bone marrow‐derived fibrocytes may play a critical role in HTS development in this animal model.
Premature Sebaceous Hyperplasia in an Adolescent Boy
Authors: WANG QIAN , LIU JING‐MU , ZHANG YI‐ZHI
Published: March 2011

Abstract:  Sebaceous hyperplasia is a common, benign condition of the sebaceous glands in adults of middle age or older, occurring primarily on the face and neck. In adolescent or young adult patients, it is a rare entity called premature sebaceous hyperplasia (PSH). Previous reports indicate that the onset of PSH occurs during or shortly after puberty, with an average age‐at‐onset of 19 years. Here we present an extremely rare prepubescent case of PSH that developed on the right side of a boy’s neck when he was 8 years old.
Congenital Vulvar Lipoma within an Accessory Labioscrotal Fold
Authors: Numajiri Toshiaki , Nishino Kenichi , Sowa Yoshihiro , Konishi Keisuke
Published: March 2011

Abstract:  Perineal lipomas are uncommon congenital anomalies. They mainly develop in male patients with an accessory scrotum, posterior to the original scrotum. However, on rare occasions, these lipomas can occur in female patients with an accessory labioscrotal fold. We report on three such cases, where the lipomas were found in the anterior part of the right side of the labia majora. None had other anomalies, with the exception of one who had premature growth of pubic hair on the accessory labioscrotal fold. Skin with a rugated scrotal appearance was present in all cases.
Biotin Deficiency in a Glycogen Storage Disease Type 1b Girl Fed Only with Glycogen Storage Disease‐Related Formula
Authors: IHARA Kenji , ABE KIYOMI , HAYAKAWA KOU , MAKIMURA MIKA , KOJIMA‐ISHII KANAKO , HARA TOSHIRO
Published: March 2011

Abstract:  Glycogen storage disease type I is an autosomal recessive disorder caused by the defect in the glucose‐6‐phosphate enzyme system. Frequent intake of glucose‐containing glycogen storage disease formula, uncooked cornstarch, or both, are usually needed to maintain normal blood glucose level. We report a glycogen storage disease type 1b girl with biotin deficiency caused by an exclusive glucose‐containing glycogen storage disease formula for years, presenting with the appearance of severe skin lesions, and diagnosed by urinary organic acid analysis by gas chromato‐spectrometry, and blood acylcarnitine analysis by tandem mass‐spectrometry.
Traction Alopecia in Two Adolescent Sikh Brothers—An Underrecognized Problem Unmasked by Migration
Authors: KARIMIAN‐TEHERANI DANIELA , El SHABRAWI‐CAELEN LAILA , TANEW ADRIAN
Published: March 2011

Abstract:  Traction alopecia denotes an often permanent hair loss resulting from prolonged physical damage to the hair shaft. We report on two adolescent Sikh brothers who wore a turban since early childhood and developed a band‐like scarring alopecia at the frontal hairline. Awareness of this condition may help in preventing irreversible hair loss by early modification of the daily hair care routine.
Effects of Membrane Molecular Weight Cutoff on Performance of a Novel Bioartificial Liver
Authors: Shi Xiao‐lei , Zhang Yue , Han Bing , Gu Jin‐yang , Chu Xue‐hui , Xiao Jiang‐qiang , Ren Hao‐zhen , Tan Jiao‐jun , Ding Yi‐tao
Published: March 2011

Immunoisolation using semipermeable membranes has been incorporated into bioartificial liver (BAL) devices to separate cellular components of the recipient's immune system from the cells within the BAL device. This study was designed to explore the influence of membrane molecular weight cutoff on performance of the multilayer radial‐flow BAL using porcine hepatocytes cocultured with mesenchymal stem cells. In this study, healthy beagles underwent 6‐h treatment with a BAL containing membrane with 200 kDa retention rating or 1200 kDa retention rating. Functional markers of BAL performance were monitored before and after treatment, as well as cytotoxic immune response to BAL therapy. The results showed that hepatocyte performance levels such as albumin secretion, urea synthesis, and viability were all significantly higher in 200 kDa retention rating group compared with the 1200 kDa retention rating group after treatment (P <  0.05). Significant levels of canine proteins were detected in BAL medium from the 1200 kDa retention rating group. Fluorescence microscopy further verified that heavy deposition of canine IgG, IgM, and complement (C3) on coculture cells was obtained after BAL treatment in the 1200 kDa retention rating group. However, only trace deposits of canine immunoproteins were observed on coculture cells obtained from BAL in the 200 kDa retention rating group. Small membrane molecular weight cutoff of the BAL could reduce the transfer of xenoreactive antibodies into the BAL medium and improve the performance of the BAL.
Development of an Implantable Myoelectric Sensor for Advanced Prosthesis Control
Authors: Merrill Daniel R. , Lockhart Joseph , Troyk Phil R. , Weir Richard F. , Hankin David L.
Published: March 2011

Modern hand and wrist prostheses afford a high level of mechanical sophistication, but the ability to control them in an intuitive and repeatable manner lags. Commercially available systems using surface electromyographic (EMG) or myoelectric control can supply at best two degrees of freedom (DOF), most often sequentially controlled. This limitation is partially due to the nature of surface‐recorded EMG, for which the signal contains components from multiple muscle sources. We report here on the development of an implantable myoelectric sensor using EMG sensors that can be chronically implanted into an amputee's residual muscles. Because sensing occurs at the source of muscle contraction, a single principal component of EMG is detected by each sensor, corresponding to intent to move a particular effector. This system can potentially provide independent signal sources for control of individual effectors within a limb prosthesis. The use of implanted devices supports inter‐day signal repeatability. We report on efforts in preparation for human clinical trials, including animal testing, and a first‐in‐human proof of principle demonstration where the subject was able to intuitively and simultaneously control two DOF in a hand and wrist prosthesis.
Foucault and Familial Power
Authors: Taylor Chloë
Published: March 2011

This paper provides an overview of Michel Foucault's continually changing observations on familial power, as well as the feminist‐Foucauldian literature on the family. It suggests that these accounts offer fragments of a genealogy of the family that undermine any all‐encompassing or transhistorical account of the institution. Approaching the family genealogically, rather than seeking a single model of power that can explain it, shows that far from this institution being a quasi‐natural formation or a bedrock of unassailable values, it is in fact a continually contested fiction that masks its own histories of becoming.
Two Kinds of Unknowing
Authors: Mason Rebecca
Published: March 2011

Miranda Fricker claims that a “gap” in collective hermeneutical resources with respect to the social experiences of marginalized groups prevents members of those groups from understanding their own experiences (Fricker 2007). I argue that because Fricker misdescribes dominant hermeneutical resources as collective, she fails to locate the ethically bad epistemic practices that maintain gaps in dominant hermeneutical resources even while alternative interpretations are in fact offered by non-dominant discourses. Fricker's analysis of hermeneutical injustice does not account for the possibility that marginalized groups can be silenced relative to dominant discourses without being prevented from understanding or expressing their own social experiences. I suggest that a gap in dominant hermeneutical resources is ambiguous between two kinds of unknowing: hermeneutical injustice suffered by members of marginalized groups, and epistemically and ethically blameworthy ignorance perpetrated by members of dominant groups.
Salmonella Enteritidis Surveillance by Egg Immunology: Impact of the Sampling Scheme on the Release of Contaminated Table Eggs
Authors: Klinkenberg Don , Thomas Ekelijn , Artavia Francisco F. Calvo , Bouma Annemarie
Published: March 2011

Design of surveillance programs to detect infections could benefit from more insight into sampling schemes. We address the effect of sampling schemes for Salmonella Enteritidis surveillance in laying hens. Based on experimental estimates for the transmission rate in flocks, and the characteristics of an egg immunological test, we have simulated outbreaks with various sampling schemes, and with the current boot swab program with a 15‐week sampling interval. Declaring a flock infected based on a single positive egg was not possible because test specificity was too low. Thus, a threshold number of positive eggs was defined to declare a flock infected, and, for small sample sizes, eggs from previous samplings had to be included in a cumulative sample to guarantee a minimum flock level specificity. Effectiveness of surveillance was measured by the proportion of outbreaks detected, and by the number of contaminated table eggs brought on the market. The boot swab program detected 90% of the outbreaks, with 75% fewer contaminated eggs compared to no surveillance, whereas the baseline egg program (30 eggs each 15 weeks) detected 86%, with 73% fewer contaminated eggs. We conclude that a larger sample size results in more detected outbreaks, whereas a smaller sampling interval decreases the number of contaminated eggs. Decreasing sample size and interval simultaneously reduces the number of contaminated eggs, but not indefinitely: the advantage of more frequent sampling is counterbalanced by the cumulative sample including less recently laid eggs. Apparently, optimizing surveillance has its limits when test specificity is taken into account.
The Rise and (Relative) Fall of Earmarks: Congress and Reform, 2006–2010
Authors: DOYLE RICHARD B.
Published: March 2011

Congressional earmark reform efforts began in 2006. This paper reviews the literature on earmarks and documents the rise and relative fall in earmark spending using four databases. It identifies and critiques earmark reforms, including congressional rules and initiatives taken by the appropriations committees and congressional party organizations. Rules and committee‐initiated reforms were the most effective, producing significant improvements in transparency and expediting availability of information. The number of earmarks and their dollar value first dropped noticeably in 2007 after an earmark moratorium, then stabilized as reforms were implemented. It is premature to conclude that reforms will alter the policy content of earmarks or their distribution.
Utilization of Employment Tax Credits: An Analysis of the Empowerment Zone Wage Tax Credit
Authors: HANSON ANDREW
Published: March 2011

This paper provides estimates of utilization for the Empowerment Zone (EZ) wage tax credit, a subsidy claimed by employers who operate in and hire residents of federally designated areas experiencing economic distress. The EZ credit is currently the largest employer‐based wage tax credit in the federal tax code in terms of dollars claimed, with almost $250 million claimed in 2002. I show that about 6.4 percent (and at least 3.5 percent) of the working age population was claimed under the EZ wage credit in 1999. In addition, I estimate that 24.2 percent (and at least 13.1 percent) of those employed inside of the target area were claimed for the credit. I create these national estimates of use with information on credit dollars claimed from the Internal Revenue Service and population data on the eligible population from the census. These measures of tax credit use are an alternative to the use rate of firms that are presented in the existing literature, and reveal how effective the credit is at reaching residents of the target area.
What Types of School Capital Projects are Voters Willing to Support?
Authors: ZIMMER RON , BUDDIN RICHARD , JONES JOHN , LIU NA
Published: March 2011

In many states, investments in school capital must be approved by bond referenda. Consequently, voter preferences can directly impact the quality of school facilities and their infrastructure. Researchers have often analyzed the causal mechanisms of referendum passage, but they have not examined whether the type of capital project affects the outcome of the referendum itself. In this paper, we use data from the state of Michigan to examine whether voters are willing to provide more or less support for specific types of capital investments. We focus on the relationship between voter support for maintenance versus the construction of a new building or additions to existing buildings. Our analysis suggests there is a higher approval rate for maintenance of existing facilities than the construction of new school buildings or additions.
Students’ engagement with their group in a problem‐based learning curriculum
Authors: McHarg J. , Kay E. J. , Coombes L. R.
Published: March 2011

Introduction:  In a new enquiry‐based learning dental curriculum, problem‐based learning (PBL) was chosen as a central methodology because it promotes a collaborative and constructive approach to learning. However, inevitably, some groups function worse than others. This study explores the relationship between group functionality and individuals’ results on knowledge‐based assessment. It also sought to establish whether using the Belbin team role theory could improve group functionality.

Methods:  Students completed the Belbin team role inventory that assigns individuals to a team role type and were allocated to either an ideal Belbin group or a control group. To evaluate the functionality of the groups, Macgowan’s group engagement measure was completed after 18 and 31 weeks for each student by their group facilitator. The scores were summed and averaged giving a group engagement score for each group. Relationships between group engagement, individual performance in assessment in weeks 18 and 31 and Belbin and non‐Belbin teams were investigated.

Results:  Individual group engagement scores and performance in the knowledge tests had a statistically significant positive relationship despite the small number of students involved (62). However, no correlation was shown between Belbin groups and group engagement scores.

Conclusions:  Those students who engaged most with the PBL process performed markedly better in assessments of knowledge. Using Belbin’s team role theory to place students in PBL groups in an effort to increase group functionality had no effect when compared with non‐Belbin control groups.
Chronic Administration of Udenafil, A Selective Phosphodiesterase Type 5 Inhibitor, Promotes Erectile Function Recovery in an Animal Model of Bilateral Cavernous Nerve Crush Injury
Authors: Lee Chan-Ho , Kim Hae-Sun , Goo Moon-Jung , Kang Kyung-Koo , Ahn Byoung-Ok , Kim Soon Hoe , Yang Dae-Yul
Published: March 2011

Introduction

Preservation of the cavernous nerves (CNs) during radical prostatectomy is crucial for the patient's erectile function. Despite advances in operative technique, the majority of men report compromised erectile function postprostatectomy or complete loss of potency due to CN trauma even with nerve-sparing modifications.

Aim

This study was designed to investigate whether repeated dosing of udenafil, a phosphodiesterase type 5 inhibitor, helps to improve erectile function after CN injury.

Methods

Using the CN crush injury model, 8-week-old male Sprague Dawley rats were divided into the following groups; sham-operated group, bilateral CN crush injury exposed to either no udenafil (vehicle) or udenafil (5, 20 mg/kg) daily for two different durations (4 and 8 weeks, p.o.).

Main Outcome Measures

At both time points, CN electrical stimulation was used to assess erectile function by measuring the intracavernous pressure. The expressions of hypoxia-inducible factor 1-alpha (HIF-1α), transforming growth factor-beta (TGF-β1), nerve growth factor (NGF), endothelin B receptor (ETB), endothelial nitric oxide synthase (eNOS), neuronal nitric oxide synthase (nNOS), and sonic hedgehog homolog (SHH) in penile tissue were examined. Immunohistochemical antibody staining was performed for NGF, eNOS, nNOS, CD31, and alpha-smooth muscle actin (α-SMA). Additionally, terminal deoxynucleotidyl transferase-mediated nick-end labeling assay was performed to quantify apoptosis and the tissue slides were stained for Masson's trichrome to assess the smooth muscle/collagen ratio.

Results

Udenafil improved erectile function in a dose- and time-dependent manner with the maximum erectile function recovery achieved by 20 mg/kg udenafil at an 8-week time point. CN injury increased the expression of HIF-1α, TGF-β1, NGF, and ETB, however, decreased the expression of eNOS, nNOS, and SHH. Udenafil significantly suppressed these alterations. The results from the histological analyses show that udenafil markedly reduces apoptosis induced by CN injury and augments the smooth muscle/collagen ratio.

Conclusions

CN injury induces significantly impaired erectile function and altered gene/protein expression. Chronic administration of udenafil preserves erectile function and has a beneficial role against the pathophysiological consequences of CN injury.
Characterization ofBacillus subtilisHC8, a novel plant‐beneficial endophytic strain from giant hogweed
Authors: Malfanova Natalia , Kamilova Faina , Validov Shamil , Shcherbakov Andrey , Chebotar Vladimir , Tikhonovich Igor , Lugtenberg Ben
Published: March 2011

Thirty endophytic bacteria were isolated from various plant species growing near Saint‐Petersburg, Russia. Based on a screening for various traits, including plant‐beneficial properties and DNA fragment patterns, potential siblings were removed. The remaining isolates were taxonomically identified using 16S rDNA sequences and potential human and plant pathogens were removed. The remaining strains were tested for their ability to promote radish root growth and to protect tomato plants against tomato foot and root rot. One strain,Bacillus subtilisHC8, isolated from the giant hogweedHeracleum sosnowskyiManden, significantly promoted plant growth and protected tomato against tomato foot and root rot. Metabolites possibly responsible for these plant‐beneficial properties were identified as the hormone gibberellin and (lipo)peptide antibiotics respectively. The antibiotic properties of strain HC8 are similar to those of the commercially available plant‐beneficial strainBacillus amyloliquefaciensFZB42. However, thin layer chromatography profiles of the two strains differ. It is speculated that endophytes such asB. subtilisHC8 contribute to the fast growth of giant hogweed.
Challenges and prospects of international marine bunker fuels demand
Authors: Mazraati Mohammad
Published: March 2011

The international marine bunker demand faces many challenges with regard to regulation on fuel quality by the International Maritime Organization (IMO). This paper reviews the most recent challenges and evolutions related to fuel demand and development in international maritime transportation. By developing a simple recursive econometric model, the future demand is forecast under the no‐policy change scenario. In the alternative scenario, the impacts of Annex VI of IMO's marine pollution convention on spread price between the high‐sulphur and low‐sulphur fuel oil are elaborated, and eventually, the impacts on future bunker demand are evaluated. The low price elasticity of bunker demand confirms minimal impacts on demand albeit considerable impacts on running cost of vessels. Bunker demand elasticity with regard to international maritime transportation is estimated at 0.55, showing that inevitable international transportation requirement is the key driver for bunker demand. Implementation of Annex VI would certainly change the mixture of bunker fuel, which mainly depends on the penetration of SO2 scrubbers on‐board of vessels and/or fuel switching. However, due to discrepancy in the level of fuel consumption and uncertain mixture of bunker fuels in the future, the refinery sector and the international maritime transportation sector would face huge uncertainties.
Impact of alternative fuels and advanced technology vehicles on oil demand in the United States up to 2030
Authors: Mazraati Mohammad , Shelbi Haithem
Published: March 2011

The increasingly high oil consumption in US road transportation sector, coupled with its significant contribution to greenhouse gases emission, resulted in the implementation of many policies geared towards addressing both challenges. Aiming to enhance the US energy security, the Energy Policy Act encourages the use of alternative fuels and has set forth the requirements for the acquisition of alternative fuels vehicles (AFVs) by Federal Agencies. This paper applies a hybrid, top‐down, two‐stage model to forecast the share of AFVs in the United States until 2030 and the resulting impact on the US oil demand. In the first stage, a logistic model is being estimated by econometric techniques to forecast the stock of vehicles as a function of socio‐economic variables, i.e. population, gross domestic product and saturation point. The second stage applies an S‐shape function to forecast the annual share of AFVs based on a trend variable that encompasses inherently fuel cost, cost of AFVs, discount rate and consumer's choice and three different AFV saturation level scenarios (2 per cent, 3 per cent, 4 per cent). The impact of AFV and advanced technologies on oil demand was calculated based on average vehicle miles driven and corporate average fuel economy possible trends for both AFVs and total vehicle stock. The paper concludes that under the 4 per cent saturation level scenario for AFVs, the oil saving is forecasted at 196,000 b/d or 1.8 per cent of total transport fuel requirements in 2030. Furthermore, it was determined that marginal increase of 1 per cent in AFVs saturation level in 2030 results in oil saving of around 49,000 b/d which represents 0.5 per cent of total fuel requirement. Overall, it was concluded that unless stringent policy measures are introduced, or a sustainable level of high oil prices is reached, there is a limited impact of AFVs on the US oil demand.
How are proliferation and differentiation of melanocytes regulated?
Authors: Hirobe Tomohisa
Published: March 2011

Coat colors are determined by melanin (eumelanin and pheomelanin). Melanin is synthesized in melanocytes and accumulates in special organelles, melanosomes, which upon maturation are transferred to keratinocytes. Melanocytes differentiate from undifferentiated precursors, called melanoblasts, which are derived from neural crest cells. Melanoblast/melanocyte proliferation and differentiation are regulated by the tissue environment, especially by keratinocytes, which synthesize endothelins, steel factor, hepatocyte growth factor, leukemia inhibitory factor and granulocyte‐macrophage colony‐stimulating factor. Melanocyte differentiation is also stimulated by alpha‐melanocyte stimulating hormone; in the mouse, however, this hormone is likely carried through the bloodstream and not produced locally in the skin. Melanoblast migration, proliferation and differentiation are also regulated by many coat color genes otherwise known for their ability to regulate melanosome formation and maturation, pigment type switching and melanosome distribution and transfer. Thus, melanocyte proliferation and differentiation are not only regulated by genes encoding typical growth factors and their receptors but also by genes classically known for their role in pigment formation.
Mesenchymal stem cell therapy for knee osteoarthritis. Preliminary report of four patients
Authors: DAVATCHI Fereydoun , ABDOLLAHI Bahar SADEGHI , MOHYEDDIN Mandana , SHAHRAM Farhad , NIKBIN Behrooz
Published: March 2011

Background:  Osteoarthritis (OA) is a cartilage degenerative process, involving the immune system, producing local inflammatory reactions, with production of pro‐inflammatory cytokines and metalloproteinases. No treatment is still available to improve or reverse the process. Stem cell therapy opened new horizons for treatment of many incurable diseases. Mesenchymal stem cells (MSCs) due to their multi‐lineage potential, immunosuppressive activities, limited immunogenicity and relative ease of growth in culture, have attracted attentions for clinical use.

Aim:  The aim of this study was to examine whether MSC transplantation could reverse the OA process in the knee joint. The project was approved by the Tehran University of Medical Sciences Research Committee and Ethical Committee.

Patients and Methods:  Four patients with knee osteoarthritis were selected for the study. They were aged 55, 57, 65 and 54 years, and had moderate to severe knee OA. After their signed written consent, 30 mL of bone marrow were taken and cultured for MSC growth. After having enough MSCs in culture (4–5 weeks) and taking in consideration all safety measures, cells were injected in one knee of each patient.

Results:  The walking time for the pain to appear improved for three patients and remained unchanged for one. The number of stairs they could climb and the pain on visual analog scale improved for all of them. On physical examination, the improvement was mainly for crepitus. It was minor for the improvement of the range of motion.

Conclusion:  Results were encouraging, but not excellent. Improvement of the technique may improve the results.
Can we reduce routine blood ordering in spinal surgery?
Authors: KOURITAS VASILEIOS , GRAHAM STEVE , MARWAH GAUTAM , PAPASTEFANOU SOTIRIS L.
Published: March 2011

Spinal reconstruction can be associated with major blood loss; because of the non existence of ordering guidelines, blood products are ordered preoperatively in excessive quantities. The aim of our study was to investigate the efficiency of our ordering routine.

The records of 205 spinal surgery patients, over a period of 3 years were reviewed. The crossmatched to transfused (C‐T) ratio was calculated for each pathology group and the safe number of units transfused was determined.

A total of 929 units were crossmatched, whereas 84 patients required transfusion. In all, 404 units were not used (C‐T ratio = 1.8). The greatest number of unused but cross matched units was observed in painful back surgery (C‐T ratio = 3.9, P < 0.01 vs. other pathologies). For all the other pathology groups (scoliosis, tumor and fracture) fewer units can be ordered, except in neuromuscular scoliosis group (6 units used on average for each case). For spinal fusion, artificial disc replacement or simple discectomy, a group and save routine is adequate.

In conclusion, less blood can be ordered for spinal surgery, except for cases of neuromuscular scoliosis. The blood units crossmatched for painful back surgery, were more than actually needed. With technological advancement historical blood crossmatching policies may need re‐evaluation.
Training young horses to social separation: Effect of a companion horse on training efficiency
Authors: HARTMANN E. , CHRISTENSEN J. W. , KEELING L. J.
Published: March 2011

Reasons for performing study: The intensity with which a horse responds to separation from its group and subsequently to being alone is relevant for both horse and handler safety. Identification of training methods that may reduce responses to separation would be useful in practice.

Objectives: To investigate whether the initial presence of a familiar companion horse modifies responses to separation from the group, lowers stress levels (as measured by heart rate) and increases training efficiency.

Hypothesis: Habituation to separation proceeds more quickly if the horse is first trained with a companion, and heart rate is lower when the horse is subsequently trained alone, compared to control horses trained individually from the start.

Methods: Young mares (n = 32), kept in groups of 4 were exposed to social separation: 2 horses of the group were trained singly (S1, n = 16) and the remaining 2 horses (n = 16) were trained first with a companion (P2) and then alone (P1). The training comprised 3 steps whereby distance from the group was gradually increased. The final learning criterion was met when a horse fed calmly alone inside a test arena (Step 3). Horses that were trained in a pair had to succeed in Step 3 together before they repeated the steps alone. Feeding behaviour and heart rate were recorded.

Results: There were no significant differences between S1 and P1 horses, indicating that the initial pair‐training did not reduce responses in P1 horses. However, heart rate was significantly lower when horses were trained in pairs (P2) compared to when the same horses were subsequently trained alone (P1).

Conclusions and potential relevance: It may not be efficient to habituate naïve young horses to social separation initially with a partner as these horses appear to have to relearn being in the test situation alone when switching to the individual training.
Writing social psychology: Fictional things and unpopulated texts
Authors: Billig Michael
Published: March 2011

This paper presents the author's position on the question how to write social psychology. It reflects the author's long‐term interest in rhetoric and his more recent concerns about the writing of social scientists. The author argues that social psychologists tend to produce unpopulated texts, writing about ‘fictional things’ rather than people. Social psychologists assume that their technical terms are more precise than ordinary language terms. The author contests this assumption. He suggests that when it comes to describing human actions, ordinary language on the whole tends to be more precise. The paper analyses why this should be the case, drawing on ideas from linguistics and Vaihinger's notion of fictions. The author presents examples to show how psychological writers, by using passives and nominals, can omit information about the agents of action and the nature of the actions that they are performing. Although their texts may appear impressively technical, they can, in fact, be highly imprecise. Moreover, social psychologists, by using this nominal style of writing, tend to write about processes as if they were things and then attribute actions to these things. In so doing, they create ‘fictional things’, which they treat as if they were real things. The author offers six recommendations for writing in simpler, clearer ways.
Use of a Continuum Damage Model Based on Energy Equivalence to Predict the Response of a Single-Crystal Superalloy
Authors: Grammenoudis P. , Reckwerth D. , Tsakmakis Ch.
Published: March 2011

Anisotropic viscoplasticity coupled with anisotropic damage has been modeled in previous works by using the energy equivalence principle appropriately adjusted. Isotropic and kinematic hardenings are present in the viscoplastic part of the model and the evolution equations for the hardening variables incorporate both static and dynamic recovery terms. The main difference to other approaches consists in the formulation of the energy equivalence principle for the plastic stress power and the rate of hardening energy stored in the material. As a practical consequence, a yield function has been established, which depends, besides effective stress variables, on specific functions of damage. The present paper addresses the capabilities of the model in predicting responses of deformation processes with complex specimen geometry. In particular, multiple notched circular specimens and plates with multiple holes under cyclic loading conditions are considered. Comparison of predicted responses with experimental results confirms the convenience of the proposed theory for describing anisotropic damage effects.
Dynamic Responses of Pile Groups Embedded in a Layered Poroelastic Half-Space to Harmonic Axial Loads
Authors: Xu Bin , Lu Jian-Fei , Wang Jian-Hua
Published: March 2011

The dynamic responses of a pile group embedded in a layered poroelastic half-space subjected to axial harmonic loads is investigated in this study. Based on Biot’s theory, the frequency domain fundamental solution for a vertical circular patch load applied in the layered poroelastic half-space is derived via the transmission and reflection matrix (TRM) method. Utilizing Muki’s method, the second kind of Fredholm integral equations describing the dynamic interaction between the layered half-space and the pile group is constructed. The proposed methodology was validated by comparing the results of this paper with a known result. Numerical results show that in a two-layered half-space, for the closely populated pile group with a rigid cap, the upper softer layer thickness has different influences on the central pile and the corner piles, while for the sparse pile group, it has almost the same influence on all the piles. For a three-layer half-space, the presence of a stiffer middle layer in the layered half-space will enhance the impedance of the pile group significantly, while a softer middle layer will reduce the impedance of the pile group.
A Study on the Relationship of Embedded Sensitivity With Measuring Grid and Mode Shapes
Authors: Kawamoto Marcos Satoshi , Nicoletti Rodrigo
Published: March 2011

Embedded sensitivity analysis has proven to be a useful tool in finding optimum positions of structure reinforcements. However, it was not clear how sensitivities obtained from the embedded sensitivity method were related to the normal mode, or operational mode, associated to the frequency of interest. In this work, this relationship is studied based on a finite element of a slender sheet metal piece, with preponderant bending modes. It is shown that higher sensitivities always occur at nodes or antinodes of the vibrating system.
Identifying Cable Tension Loss and Deck Damage in a Cable-Stayed Bridge Using a Moving Vehicle
Authors: Yin Shih-Hsun , Tang Chung-Yu
Published: March 2011

This paper presents a computational study on a new method of detecting multiple simultaneous damages in a cable-stayed bridge by use of the analysis of the vertical dynamic response of a vehicle passing the bridge. First, the study uses a finite-element method to simulate the vehicle cable-stayed bridge system. Then, the vertical vibration interaction between the bridge and the vehicle is solved by a time-step integration scheme. In this research, we consider that two kinds of damage including cable tension loss and deck damage may occur simultaneously at different locations. The differences between the vertical displacement responses of a vehicle passing the damaged bridge and the healthy bridge are sampled and called the relative displacement response vector of the vehicle. The proper orthogonal decomposition (POD) is utilized to decompose the relative displacement response vector of the vehicle passing the bridge with unknown multiple damages into an optimal set of basis vectors formed from the ones of the vehicle moving over the known damaged bridges. The associated system parameters variation with the unknown multiple damages can be reconstructed further. Discussions are given concerning the feasibility and limitation of the proposed detection technique as well as directions for future research.
Boiling Heat Transfer and Flow Regimes in Microchannels—A Comprehensive Understanding
Authors: Harirchian Tannaz , Garimella Suresh V.
Published: March 2011

Flow boiling in microchannels has been investigated extensively over the past decade for electronics cooling applications; however, the implementation of microchannel heat sinks operating in the two-phase regime in practical applications has lagged due to the complexity of boiling phenomena at the microscale. This has led to difficulties in predicting the heat transfer rates that can be achieved as a function of the governing parameters. From extensive experimental work and analysis performed in recent years, a clear picture has emerged that promises to enable prediction of flow boiling heat transfer over a wide parameter space. Experiments have been conducted to determine the effects of important geometric parameters such as channel width, depth, and cross-sectional area, operating conditions such as mass flux, heat flux, and vapor quality, as well as fluid properties, on flow regimes, heat transfer coefficients, and pressure drops in microchannels. A detailed mapping of flow regimes occurring under different conditions has been facilitated with high-speed flow visualizations. In addition, quantitative criteria for the transition between macro- and microscale boiling behaviors have been identified. In this paper, these recent advances toward a comprehensive understanding of flow boiling in microchannels are summarized.
Fractional Control With a Smith Predictor
Authors: Jesus Isabel S. , Machado J. Tenreiro
Published: March 2011

The advantageous use of fractional calculus (FC) in the modeling and control of many dynamical systems has been recognized. In this paper, we study the control of a heat diffusion system based on the application of the FC concepts. Several algorithms are investigated and compared, when integrated within a Smith predictor control structure. Simulations are presented assessing the performance of the proposed fractional algorithms.
Transient Performance of Micro-Tubular Solid Oxide Fuel Cells
Authors: Howe Katie S. , Kendall Kevin
Published: March 2011

The transient performance of microtubular solid oxide fuel cells was investigated, with promising results. It was found that a single cell can take less than half a second to adjust to load changes, even when the change steps across the majority of the cell’s range. In addition, no undershooting of the voltage step was seen in these tests. When steps of equal size were ranged across the current-voltage spectrum, more distortion was seen at the higher voltages. Cells with cathodes applied by dip-coating (instead of brush-painting) were then dynamically tested in a similar way. Their transient performance was significantly weaker, with visible undershooting and longer re-adjustment times of 10–15 s. This is thought to be due to the difference in the microstructure of the cathode layers made by the different coating methods.
Study on Machinabilty of Al2O3 Ceramic Composite in EDM Using Response Surface Methodology
Authors: Patel K. M. , Pandey Pulak M. , Rao P. Venkateswara
Published: March 2011

Electric discharge machining (EDM) has been proven as an alternate process for machining complex and intricate shapes from the conductive ceramic composites. Al2O3 based electrodischarge machinable Al2O3–SiCw–TiC ceramic composite is a potential substitute for traditional materials due to their high hardness, excellent chemical, and mechanical stability under a broad range of temperature, and high specific stiffness. The right selection of the machining condition is the most important aspect to take into consideration in the EDM. The present work correlates the inter-relationships of various EDM machining parameters, namely, discharge current, pulse-on time, duty cycle, and gap voltage on the metal removal rate (MRR), electrode wear ratio (EWR), and surface roughness using the response surface methodology (RSM) while EDM of Al2O3–SiCw–TiC ceramic composite. Analysis of variance is used to study the significance of process variables on MRR, EWR, and surface roughness. The experimental results reveal that discharge current, pulse-on time, and duty cycle significantly affected MRR and EWR, while discharge current and pulse-on time affected the surface roughness. The validation of developed models shows that the MRR EWR and surface roughness of EDM of Al2O3–SiCw–TiC ceramic can be estimated with reasonable accuracy using the second-order models. Finally, trust-region method for nonlinear minimization is used to find the optimum levels of the parameters. The surface and subsurface damage have also been assessed and characterized using scanning electron microscopy. This study reveals that EDMed material unevenness increases with discharge current and pulse-on time.
Microstructure and Properties of the Composites: Hydroxyapatite With Addition of Zirconia Phase
Authors: Dudek Agata
Published: March 2011

The group of bioceramics includes hydroxyapatites, which, due to their specific properties, are widely used in biotechnology. These compounds exist in skeletons of human and animal bodies. A range of advantages of implants, which contain, among other things, hydroxyapatites, results also from the level of their porosity. Recent trends that focus on the improvement in poor strength properties of HA coatings include the introduction of solid solution of Y2O3 in ZrO2 (Khalil et al., 2007, “Consolidation and Mechanical Properties of Nanostructured Hydroxyapatite Bioceramics by High Frequency Induction Heat Sintering,” Mater. Sci. Eng., 456, pp. 368–372; Chevalier et al., 2004, “Critical Effect of Cubic Phase on Aging in 3 mol % Yttria-Stabilized Zirconia Ceramics for Hip Replacement Prothesis,” Biomaterials, 25, pp. 5539–5545; Inuzuka et al., 2004, “Hydroxyapatite-Deped Zirconia for Preparation of Biomedical Composites Ceramics,” Solid State Ionics, 172, pp. 509–513; Sung, Y. M., and Kim, D. H., 2003, “Crystallization Characteristics of Yttria-Stabilized Zirconia/Hydroxyapatite Composite Nanopowder,” J. Cryst. Growth, 254, pp. 411–417; Marciniak, J., 2002, Biomateriały, Wydawnictwo Politechniki Śląskiej, Gliwice, Poland; Park J., and Bronzino J. D., 2000, Biomaterials, CRC, Boca Raton, FL; Yoshida et al., 2006, “Fabrication of Structure-Controlled Hydroxyapatite/Zirconia Composite,” J. Eur. Ceram. Soc., 26, pp. 515–518). It seems essential to determine the resulting structural and strength properties in the aspect of further application of composites based on hydroxyapatite with the addition of the zirconia phase. The investigations involved ceramic composites based on HA with different amounts of the phase modified with ZrO2 yttrium dioxide.
Study of Machining-Induced Microstructure Variations of Nanostructured/Ultrafine-Grained Copper Using XRD
Authors: Huang Yong , Morehead Mason
Published: March 2011

Various methods for the production of bulk nanostructured (NS)/ultrafine-grained (UFG) materials have been developed, including equal channel angular extrusion (ECAE), a form of severe plastic deformation. Using an ECAE NS/UFG copper bar as an example, this study has investigated machining-induced workpiece microstructure variation using X-ray diffraction. It has been found that (1) under gentle cutting conditions, there was a 10% increase in the median grain size compared with unmachined ECAE NS/UFG copper bars. Increases in the arithmetic-, area-, and volume-weighted grain sizes were found to be 10%, 8%, and 8%, respectively, and (2) an average 27% drop in the dislocation density was observed between the machined and unmachined ECAE copper bars. The dislocation density was shown to have the most reduction (−39%) at the outer radius of the machined ECAE bar where more heat and/or higher pressure were experienced.
Diurnal Temperature and Pressure Effects on Axial Turbomachinery Stability in Solid Oxide Fuel Cell-Gas Turbine Hybrid Systems
Authors: Maclay James D. , Brouwer Jacob , Samuelsen G. Scott
Published: March 2011

A dynamic model of a 100 MW solid oxide fuel cell-gas turbine hybrid system has been developed and subjected to perturbations in diurnal ambient temperature and pressure as well as load sheds. The dynamic system responses monitored were the fuel cell electrolyte temperature, gas turbine shaft speed, turbine inlet temperature, and compressor surge. Using a control strategy that primarily focuses on holding fuel cell electrolyte temperature constant and secondarily on maintaining gas turbine shaft speed, safe operation was found to occur for expected ambient pressure variation ranges and for ambient temperature variations up to 28 K when tested nonsimultaneously. When ambient temperature and pressure were varied simultaneously, stable operation was found to occur when the two are in phase but not when the two are out of phase. The latter case leads to shaft overspeed. Compressor surge was found to be more likely when the system is subjected to a load shed initiated at minimum ambient temperature rather than at maximum ambient temperature. Fuel cell electrolyte temperature was found to be well-controlled except in the case of shaft overspeeds. Turbine inlet temperature remained in safe bounds for all cases.
Development of Delphi-Type Compact Thermal Models for Opto-Electronic Packages
Authors: Raghupathy Arun Prakash , Janssen John , Aranyosi Attila , Ghia Urmila , Ghia Karman , Maltz William
Published: March 2011

In the current study, a network-based resistor model has been developed for thermal analysis of a complex opto-electronic package called small form-factor pluggable device (SFP). This is done using the DEvelopment of Libraries of PHysical models for an Integrated design (DELPHI) methodology. The SFP is an optical transceiver widely used in telecommunication equipments such as switches and routers. The package has a detailed construction and typically has four fixed heat generating sources. The detailed model for the SFP is constructed and calibrated using a natural convection experiment. The calibrated detailed model is used for generating the limited boundary-condition-independent compact thermal model (CTM). Limited boundary-condition-independence, in this case, refers only to a small subset of all “thinkable” boundary conditions that are experienced by the SFP device in practical situations. The commercial optimization tool developed by the DELPHI team, DOTCOMP, is used for generating the compact thermal model. A detailed validation of the CTM of the SFP in real-time applications using FLOTHERM 7.2, a computational fluid dynamics-based thermal analysis software package, is performed. The results show excellent agreement between the results predicted by the SFP CTM with the data from the detailed model. The SFP CTM predicts the junction temperature of the four power-dissipating components and the heat flows through the sides with relative error less than 10%.