bluuebunny/crossref_metadata_2025 huggingface dataset:
Parental Presence and Encouragement Do Not Influence Helping in Young Children
Authors: Warneken Felix , Tomasello Michael
Published: March 2012

Young children begin helping others with simple instrumental problems from soon after their first birthdays. In previous observations of this phenomenon, both naturalistic and experimental, children’s parents were in the room and could potentially have influenced their behavior. In the two current studies, we gave 24‐month‐old children the opportunity to help an unfamiliar adult obtain an out‐of‐reach object when the parent (or a friendly female adult) (i) was present but passive, (ii) was present and highlighted the problem for the child, (iii) was present and actively encouraged the child to help, (iv) was present and ordered the child to help, or (v) was absent from the room. The children helped at relatively high levels and equally under all these treatment conditions. There was also no differential effect of treatment condition on children’s helping in a subsequent test phase in which no parent was present, and children had to disengage from a fun activity to help. Young children’s helping behavior is not potentiated or facilitated by parental behavior in the immediate situation, suggesting that it is spontaneous and intrinsically motivated.
Effects of Ownership Rights on Conflicts Between Toddler Peers
Authors: Ross Hildy S.
Published: March 2012

This study examined property conflicts in thirty‐two 20‐ and 30‐month‐old peer dyads during eighteen 40‐min play sessions. Ownership influenced conflicts. Both 20‐ and 30‐month‐old owners claimed ownership (“mine”) and instigated and won property conflicts more often than non‐owners. At 30 months, owners also resisted peers’ instigations more often than non‐owners. Mothers’ interventions supported non‐owners more often than owners, in part because owners initiated conflict more frequently. Children who received mothers’ support tended to win disputes. Finally, mothers’ support of owners and children’s adherence to ownership rights led to decreased conflict as relationships developed, supporting predictions based on theories concerning the social utility of ownership rights.
Evaluation of the tolerability and immunogenicity of ultraviolet C‐irradiated autologous platelets in a dog model
Authors: Pohler Petra , Lehmann Jörg , Veneruso Verena , Tomm Janina , von Bergen Martin , Lambrecht Bernd , Kohn Barbara , Weingart Christiane , Müller Thomas H. , Seltsam Axel
Published: March 2012

BACKGROUND: The THERAFLEX ultraviolet (UV) platelets (PLTs) pathogen reduction system for PLT concentrates (PCs) operates using ultraviolet C (UVC) light at a wavelength of 254 nm. UVC treatment can potentially alter proteins, which may affect drug tolerance in humans and influence the immunogenicity of blood products. This preclinical study in beagle dogs was designed to evaluate the safety pharmacology of UVC‐irradiated PCs after intravenous administration and to determine whether they are capable of eliciting humoral responses to PLTs and plasma proteins.

STUDY DESIGN AND METHODS: Six beagle dogs each were transfused once every other week for 10 weeks with UVC‐irradiated or nonirradiated PCs. All PCs were autologous canine single‐donor products prepared from whole blood. Safety pharmacology variables were regularly assessed. The impact of UVC irradiation on PLT and plasma proteomes was analyzed by one‐ and two‐dimensional gel electrophoresis. Serum samples were tested for UVC‐induced antibodies by Western blot and flow cytometry.

RESULTS: Dogs transfused with UVC‐irradiated PCs showed no signs of local or systemic intolerance. Few but significant changes in PLT protein integrity were observed after UVC irradiation. Even after repeated administration of UVC‐irradiated PCs, no antibodies against UVC‐exposed plasma or PLT proteins were detected.

CONCLUSIONS: Repeated transfusions of autologous UVC‐treated PCs were well tolerated in all dogs studied. UVC irradiation did not cause significant plasma or PLT protein modifications capable of inducing specific antibody responses in the dogs. High‐resolution proteomics combined with antibody analysis introduces a comprehensive and sensitive method for screening of protein modifications and antibodies specific for pathogen reduction treatment.
Switching iron‐deficient whole blood donors to plateletpheresis
Authors: O'Meara Alix , Infanti Laura , Sigle Jörg , Stern Martin , Buser Andreas
Published: March 2012

BACKGROUND: Iron deficiency is a frequent side effect of whole blood (WB) donation. In contrast, less red blood cell loss and therefore less iron loss results from plateletpheresis.

STUDY DESIGN AND METHODS: WB donors presenting a decrease in either hemoglobin (Hb) or ferritin levels were offered to switch to plateletpheresis with or without iron supplementation. We analyzed the effect of this intervention on deferral rates for an insufficient Hb level in 168 donors. Further, we assessed how this intervention affected Hb and ferritin levels, anemia occurrence, and platelet (PLT) concentrate yields in the donors who presented at least four successive times for thrombapheresis.

RESULTS: Switching WB donors to repetitive plateletpheresis procedures resulted in an increase of median Hb (+12 g/L, p < 0.001) and ferritin (+15.5 ng/mL, p = 0.002) values. Anemia and deferral rates were reduced by 23% (p = 0.004) and 13% (p < 0.001). Between high‐ and low‐frequency apheresis donors, no significant differences in Hb and ferritin levels were found. Similarly, discrepancies in Hb and ferritin values between donors that adopted iron supplementation and those who did not were insignificant. The median PLT concentrate yield was 5.43 × 1011 PLTs.

CONCLUSION: Switching iron‐deficient WB donors to plateletpheresis was an effective intervention that permitted us to correct low Hb and ferritin levels while retaining donors in our pool.
The Determinants of the Structure of Rainy Day Funds
Authors: Rodríguez‐Tejedo Isabel
Published: March 2012

This article investigates the factors that determine the configuration of budget stabilization funds, also known as rainy day funds, along their two most important dimensions: deposit and withdrawal requirements. These funds are created to accumulate savings in order to reduce the impact of adverse fiscal conditions during downturns. The effectiveness of such funds depends greatly on their institutional structure, and yet most states choose configurations that compromise their efficacy. Using multinomial discrete techniques, and introducing the ordered nature of the requirements in the analysis, the results of this study indicate that political and institutional factors such as the size of the house of the legislature and some strict institutions are associated with weak budget stabilization funds, while economic factors such as the volatility of state tax revenues are associated with stricter funds.
Anomalous Chord of the Left Atrium without Involvement of the Mitral Valve
Authors: Arya Bhawna , Challenger Margaret , Lai Wyman W.
Published: March 2012

An anomalous chord from the left side of the atrial septum to the left atrial free wall was incidentally noted on transthoracic echocardiography in a 14‐year‐old boy with vasovagal syncope. Previously reported cases of anomalous chords in the left atrium were associated with the mitral valve leaflets in all but two cases. This is the first reported case of an echocardiographic diagnosis of anomalous left atrial chord without insertion of the chord into the mitral valve.
A Reversal of Political Fortune: The Transitional Dynamics of Conservative Rule in the Brazilian Northeast
Authors: Montero Alfred P.
Published: March 2012

This study explains the erosion of conservative rule and the rise of leftist opposition at the subnational level in the Northeast of Brazil in recent electoral cycles. Compared with explanations based on economic modernization, social spending, and fiscal reform, the data best support the hypothesis that the organizational and spatial dimensions of leftist mobilization in these states have shifted to the detriment of conservative machines. Specifically, urban mobilization of leftist supporters has determined the electoral success of these oppositions. The study also explains where conservatives maintain a floor of support based on the continuation of clientele networks.
The Ecuadorian Army: Neglecting a Porous Border While Policing the Interior
Authors: Jaskoski Maiah
Published: March 2012

This article challenges two prominent explanations for military behavior: militaries, like other bureaucracies, will seek to maximize their budgets; and in the interest of maintaining professionalism, militaries will perform sovereignty missions—external defense and counterinsurgency—more intensively than policing functions. Running counter to these expectations, since 2000, Ecuador’s army has neglected its professional, lucrative mission of northern border defense, instead focusing on police work. The analysis applies organization theory to argue that the army’s minimal border defense efforts have been a way to maintain predictability for patrols on the ground, the part of the army that most directly performs the army’s core function of security. Specifically, the article traces how a contradiction has emerged in the army’s border mission. The contradiction has meant anything but predictability for the work of troops patrolling the border, compromising the mission.
Concordance of genetic and phenotypic characters across a sapsucker hybrid zone
Authors: Seneviratne Sampath S. , Toews David P. L. , Brelsford Alan , Irwin Darren E.
Published: March 2012

Hybridization has presented a challenge for taxonomists and conservation biologists, since hybridizing forms could be stable evolutionary entities or ephemeral forms that are blending together. However, hybrid zones also provide a unique opportunity for evolutionary biologists who study the interaction between gene flow and reproductive isolation in speciation. Three forms of woodpeckers (sapsuckers; genusSphyrapicus) in North America that are mostly geographically separated but hybridize with each other where they come into contact present a remarkable system for the study of hybridization. We provide the first comprehensive analysis of phenotypic and genetic variation across a hybrid zone between two of these forms, the red‐breastedSphyrapicus ruberand yellow‐belliedS. variussapsuckers. The objective was to infer whether selection maintains the differences between forms. Our analysis of eight morphometric and 20 plumage traits, and two molecular markers showed clear differences between the forms and roughly concordant clinal variation across a narrow hybrid zone. Thirty percent of sampled birds in the hybrid zone had mixed west/east genotypes at the genetic markers examined. The center of the genetic cline was located 20 km west of the crest of the Rocky Mountains. The width of the zone was 122 km, narrower than would be expected under neutral blending given reasonable estimates of the age of the zone and individual dispersal distances. Heterozygote deficit and cytonuclear disequilibrium at the centre of the hybrid zone suggested nonrandom mating or limited hybridization. Given these patterns and lack of evidence for habitat segregation we conclude that this hybrid zone is maintained by selection, most likely in the form of hybrid inferiority. This study provides an illustrative example of extensive hybridization between stable entities, providing additional evidence against the historical practice of treating hybridizing forms as members of the same species.
The combination of bortezomib and dexamethasone is an efficient therapy for relapsed/refractory scleromyxedema: a rare disease with new clinical insights
Authors: Cañueto Javier , Labrador Jorge , Román Concepción , Santos‐Briz Ángel , Contreras Teresa , Gutiérrez Norma Carmen , García‐Sanz Ramón
Published: March 2012

Scleromyxedema (SM) is a rare primary cutaneous inflammatory mucinosis characterised by papular mucinosis, monoclonal gammopathy and extracutaneous involvement. Most therapeutic options have failed in SM but high‐dose therapy followed by autologous peripheral blood stem cell transplantation (APBSCT) appears to be highly effective, although SM normally relapses. We report the case of a 29‐yr‐old patient with severe SM who achieved stringent complete response with Bortezomib plus Dexamethasone after an early relapse subsequent to a high‐dose melphalan regimen followed APBSCT. It is of particular note that dermatological lesions responded to both therapies before M‐component modifications, suggesting that SM is independent of M‐component characteristics. However, treatment should be directed towards the underlying plasma cell malignancy with typical anti‐myeloma agents.
Microbial immobilization drives nitrogen cycling differences among plant species
Authors: Laungani Ramesh , Knops Johannes M. H.
Published: March 2012

In many terrestrial ecosystems nitrogen (N) limits productivity and plant community composition is influenced by N availability. However, vegetation is not only controlled by N; plant species may influence ecosystem N dynamics through positive or negative effects on N cycling. We examined four potential mechanisms of plant species effects on nitrogen (N) cycling. We found no species differences in gross ammonification suggesting there are no changes in the ecosystem N cycling rate between the soil organic matter pool (SOM) and the plant/microbial pool. We also found weak differences among plant species in gross nitrification, thus plant species only marginally change the relative sizes of the NH4+ and NO3− pools. Next, more than 90% of mineralized N was microbially immobilized, and microbial N immobilization was positively correlated with root biomass. Finally, while species differed in extractable soil NO3− concentration, these differences were not related to root biomass suggesting that microbial immobilization drives net N mineralization and soil NO3− levels. Our results indicate that plant species do not cause feedbacks on the N cycling rate among the three major ecosystem N pools over nine years. However, plant carbon (C) inputs to the soil control microbial N immobilization and thereby change N partitioning between the plant and microbial N pools. Furthermore our results suggest that the SOM pool can act as a strong bottleneck for N cycling in these systems.
Identification of feeding risk factors for impaired nutrition status in paediatric patients with cerebral palsy
Authors: Karagiozoglou‐Lampoudi Thomais , Daskalou Efstratia , Vargiami Euthymia , Zafeiriou Dimitrios
Published: March 2012

Aim:  To assess the nutrition status of children with CP, applying WHO growth standards, to indentify feeding risk factors and to evaluate their impact on the growth of children with CP.

Methods:  In 42 paediatric patients (mean age 8.00 ± 4.00 years), anthropometry and food intake records were assessed. z‐scores were calculated using WHO Anthro software. Intake to requirements ratio (I/R) was calculated, and patients were classified according to their feeding ability (PFA). Overall diet quality was assessed using the Diet Quality Index International (DQI‐I).

Results:  Based on WAz, 15 patients (38.1%) were undernourished. No association was found between I/R ratio and BMI z‐score, while PFA and DQI‐I displayed a significant correlation to both (p < 0.05). Diet Quality Index International was also correlated with macronutrient distribution (p < 0.05). Patients with CP were undernourished in a considerable proportion. Malnutrition in patients with CP is not associated with the intake of estimated energy requirements. Among the other feeding risk factors studied, PFA and DQI‐I represented important parameters associated with malnutrition.

Conclusion:  WHO z‐scores represent accurate parameters for the assessment of malnutrition in patients with CP. Together with anthropometry and PFA evaluation, the use of the DQI‐I would add prognostic value to both the initial growth assessment and the patients’ growth monitoring.
Paediatric drug use with focus on off‐label prescriptions at Swedish hospitals – a nationwide study
Authors: Kimland E , Nydert P , Odlind V , Böttiger Y , Lindemalm S
Published: March 2012

Aim:  To perform a nationwide investigation of paediatric drug use at Swedish hospitals, including an analysis of off‐label drug use.

Methods:  All paediatric hospitals in Sweden were invited to register all prescriptions to children, aged between 0 and 18, during two separate 2‐day‐periods in 2008. Data were reported and analysed with respect to licence status and proportion of and reasons for off‐label drug use.

Results:  Data on 11 294 prescriptions to 2947 paediatric patients were received. Drugs associated with pain relief, infection, prematurity, nutrition and surgery or anaesthesia were most commonly used. Paracetamol was the most frequently used drug on‐label and also among the most commonly used off‐label drugs. Nearly half (49%) of all administered prescriptions concerned unlicensed drugs, off‐label drugs or extemporaneously prepared drugs. The corresponding rate among neonates was 69%. Lack of paediatric information in the Summary of Product Characteristics was the main reason for off‐label classification.

Conclusions:  Paediatric off‐label drug use is common at Swedish hospitals, and nearly half of all prescriptions were not documented for use in children. The findings emphasize a need for paediatric clinical studies as well as compilation of existing clinical experience and scattered evidence, particularly for drug treatment in infants and neonates.
Prepubertal follow‐up after hypospadias repair with autologous in vitro cultured urothelial cells
Authors: Fossum Magdalena , Skikuniene Jurate , Orrego Abiel , Nordenskjöld Agneta
Published: March 2012

Aim:  To evaluate the long‐term effects on hypospadias repair with cultured autologous urothelial cells.

Methods:  From 2000 to 2002, six patients with scrotal or perineal hypospadias and pronounced chordee were treated surgically with cultured autologous urothelial cell transplants. All patients were evaluated at 6–8 years postoperatively, that is, in the prepubertal period. The outcome was assessed with respect to cosmetic appearance, voiding function, urinary flow, artificial erection, urethroscopy and biopsies.

Results:  Median follow‐up time was 7.25 years. Up to date, all patients present with a good cosmetic appearance. One of the boys prefers a sitting voiding position. Urinary flow curves are bell‐shaped in all but one. All have straight erections, urethroscopy reveals an even, non‐hair‐bearing surface on the transplanted side and 2/6 present with urothelial cells in biopsies. Limitations of this follow‐up study include a small group of patients and lack of controls. However, patients with severe hypospadias have high complication rates, and our results are equal or better than expected for the phenotype.

Conclusion:  Tissue engineering for severe hypospadias repair can be performed in a safe manner. The method is feasible for treatment of a selected group of hypospadias, where pronounced chordee and shortage of preputial and penile skin complicates the creation of a neourethra.
Genetic basis of apnoea of prematurity and caffeine treatment response: role of adenosine receptor polymorphisms
Authors: Kumral Abdullah , Tuzun Funda , Yesilirmak Didem Cemile , Duman Nuray , Ozkan Hasan
Published: March 2012

Aim:  Caffeine treatment reduces the frequency of apnoea of prematurity (AOP) and eliminates the need for mechanical ventilation by acting as a nonspecific inhibitor of adenosine A1 and adenosine 2A receptors. Patients with AOP have demonstrated variant responses to caffeine therapy. We proposed to investigate the role of A1 and 2A polymorphisms in the development of AOP and individual differences in caffeine response. Secondly, we aimed to determine whether these polymorphisms have any effect on bronchopulmonary dysplasia (BPD) development.

Methods:  Cord blood samples were collected from infants born with gestational ages between 24 and 34 weeks. Two groups were defined: patients without apnoea (n = 60) and patients with apnoea (n = 55). Patients with apnoea were divided into two subgroups: a caffeine‐responsive group (n = 30) and an unresponsive group (n = 25). Six single‐nucleotide polymorphisms were chosen for genotyping.

Results:  Patients with apnoea over 28 weeks of gestational age who responded to the caffeine treatment were found to carry the rs16851030 C/C genotype rather than the C/T or T/T genotype. Logistic regression analysis showed a significant correlation between rs35320474‐C/T and T/T genotypes and apnoea and BPD development.

Conclusion:  Our results indicate a role for adenosine receptor gene polymorphisms in susceptibility to AOP and BPD and in interindividual variability to caffeine response.
Decisionmaking Regarding Unwanted Pregnancy among Adolescents in Mexico City: A Qualitative Study
Authors: Tatum Carrie , Rueda Marcela , Bain Jennifer , Clyde Jessie , Carino Giselle
Published: March 2012

Adolescents in Latin America and the Caribbean confront difficult decisions when faced with unwanted pregnancies, especially given the region's legal restrictions on and widespread cultural opposition to abortion. Little research has been conducted on pregnancy decisionmaking among young people in this region. This study examines the role of peers, partners, family members, and health‐care providers in adolescents' decisionmaking regarding pregnancy continuation or termination in Mexico City shortly after abortion was legalized in 2007. Qualitative in‐depth interviews and focus group discussions were conducted in 2009 with participants aged 13–17 who experienced an unwanted pregnancy. Although participants were able to formulate preferences regarding pregnancy resolution, parents' wishes usually prevailed when their wishes conflicted. Peers were generally found to be supportive, whereas the role of partners varied. Results indicate the need for comprehensive sexuality education to promote adolescents’ autonomy, mechanisms other than legal mandates to encourage constructive parental involvement, and confidential counseling from health professionals offering options and supporting adolescents' ability to act on their decisions.
The visualisation and speed of kill of wound isolates on a silver alginate dressing
Authors: Hooper Samuel J , Percival Steven L , Hill Katja E , Thomas David W , Hayes A J , Williams David W
Published: March 2012

In chronic wound management, alginate dressings are used to absorb exudate and reduce the microbial burden. Silver alginate offers the added benefit of an additional antimicrobial pressure on contaminating microorganisms. This present study compares the antimicrobial activity of a RESTORE silver alginate dressing with a silver‐free control dressing using a combination of in vitro culture and imaging techniques. The wound pathogens examined included Candida albicans, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, β‐haemolytic Streptococcus, and strictly anaerobic bacteria. The antimicrobial efficacy of the dressings was assessed using log10 reduction and 13‐day corrected zone of inhibition (CZOI) time‐course assays. Confocal laser scanning microscopy (CLSM) was used to visualise the relative proportions of live/dead microorganisms sequestered into the dressings over 24 hours and estimate the comparative speed of kill. The RESTORE silver alginate dressing showed significantly greater log10 reductions and CZOIs for all microorganisms compared with the control, indicating the antimicrobial effect of ionic silver. Antimicrobial activity was evident against all test organisms for up to 5 days and, in some cases, up to 12 days following an on‐going microbial challenge. Imaging bacteria sequestered in the silver‐free dressing showed that each microbial species aggregated in the dressing and remained viable for more than 20 hours. Growth was not observed inside of the dressing, indicating a possible microbiostatic effect of the alginate fibres. In comparison, organisms in the RESTORE silver alginate dressing were seen to lose viability at a considerably greater rate. After 16 hours of contact with the RESTORE silver alginate dressing, >90% of cells of all bacteria and yeast were no longer viable. In conclusion, collectively, the data highlights the rapid speed of kill and antimicrobial suitability of this RESTORE silver alginate dressing on wound isolates and highlights its overwhelming ability to manage a microbial wound bioburden in the management of infected wounds.
CONTEMPORARY LABOR AND CULTURAL EXCHANGE
Authors: Kroik Polina
Published: March 2012

This introduction to the special issue on “Contemporary Labor and Cultural Exchange” argues for the importance of the category of labor to the study of contemporary transnational literatures and cultures. Responding to dominant discourses on globalization as well as the debate about “world literature” within literary studies, the introduction suggests that increased attention to the routes of labor migration and cultural representations of exploited migrant labor offers a new, productive approach to the study of contemporary literature and culture. In contrast to the celebratory rhetoric of globalization which represents a “flat” and democratically interconnected world, the focus on labor migration brings to light the persistence of uneven development and exploitation, and the frequent isolation of migrant workers, even as the surplus value they generate plays a major role in the global economy. Written at a time when many U.S.‐based universities are adopting the neoliberal practices of global corporations, the attention to labor in literary and cultural studies also places an emphasis on the material conditions of academic production and scholars' embeddedness in economic processes. An approach to transnational literature which follows the cartography of labor migration and uneven development could become a vital alternative to the “world literature” curriculum which tends to disregard economic inequality.
COSMOPOLITANISM, ETHNIC BELONGING, AND AFFECTIVE LABOR: HAN ONG'S FIXER CHAO AND THE DISINHERITED
Authors: Patterson Christopher B.
Published: March 2012

Asian American literature has often depicted the Filipino service laborer as a figure desiring global belonging, forgetting that figure's opposite: the cosmopolitan, Asian American client who desires “ethnic belonging” by consuming Filipino service labor. Drawing on Pheng Cheah's notions of cosmopolitanism, Patterson investigates a dual concept of cosmopolitanism that sees elite migrants as “high cosmopolitans,” and services workers as “low cosmopolitans.” Through two novels by the Filipino migrant writer Han Ong, Patterson compares Ong's “low‐cosmopolitan” service laborers, who are motivated by a desire for high cosmopolitanism, with their “high‐cosmopolitan” clients, who seek an ethnic authenticity that can only be provided through the affective laborer. As Patterson argues, the contradiction between the commodification of Asian cultures and the vulnerability of the worker raises questions about diasporic subjectivity and contemporary multicultural ideals as they intersect with mobility, class, and service labor.
Dielectric and Mechanical Properties of Hot‐Pressed Sintered Csf/Al2O3 Ceramic Composites
Authors: Huang Zhibin , Zhou Wancheng , Ma Rufei , Tang Xiufeng , Luo Fa , Zhu Jiankun
Published: March 2012

High densified Csf/Al2O3 ceramic composites were prepared by hot‐pressed sintering using α‐Al2O3 powders and short carbon fibers as starting materials. Dielectric and mechanical properties of these composites were evaluated. The results show that the addition of short carbon fiber (Csf) conducting fillers renders the composites radar absorbing ability, while the hardness around 90 HRF and strength around 300 MPa are also obtained in these composites. Both the fiber content and the length can be used to optimize the dielectric property at the frequency range 8.2–12.4 GHz. The results indicate that Csf/Al2O3 composite is a promising radar absorbing material with load‐bearing ability.
SiC Ceramic‐Bonded Carbon Fabricated With Si3N4 and Carbon Powders
Authors: Chen Weiwu , Tojo Tetsuro , Miyamoto Yoshinari
Published: March 2012

New composites called ceramic‐bonded carbon (CBCs), consisting of a three‐dimensional structure of carbon particles bonded with thin ceramic boundaries, were developed. To fabricate light and tough CBCs and to understand their reinforcing mechanism, Si3N4 and carbon powders (25:75 in volume ratio) were gelcasted and then sintered by spark plasma sintering at temperatures of 1700–1900°C. The ceramic boundary of SiC was formed in situ at above 1700°C by the reaction of Si3N4 and C. The sintered CBCs showed a unique microstructure consisting of carbon particles and ceramic boundaries of 15 μm in size and 0.5–3 μm in thickness, respectively. With an increase in sintering temperature, physical bonding of ceramic grains to the carbon particles was enhanced as the grain growth of SiC increased. The SiC/CBCs sintered at 1900°C were highly dense (97% theoretical density), lightweight (2.36 mg/m3), and had both relatively high bending strength and thermal conductivity (135 MPa and 140 W/mK, respectively).
Phase Evolution of Ti3SiC2 Annealing in Vacuum at Elevated Temperatures
Authors: Zeng Junling , Ren Shufang , Lu Jinjun
Published: March 2012

The thermal decomposition of Ti3SiC2 in vacuum furnace up to 1500°C has been investigated. The results show that the mild decomposition of Ti3SiC2 commences at 1300°C and the higher the holding temperature, the larger the volatilization of Si atoms. The Ti3SiC2 decomposition occurs simultaneously on the surface and in the bulk. Four phases coexist at 1400°C and 1450°C and the Ti5Si3Cx phase appears in the bulk and/or surface. Diffusion distance, rate, and volatilization of Si contribute to the porous structure and the presence of Ti5Si3Cx. The evolution of furnace pressure reflects the decomposition kinetics of Ti3SiC2.
Synthesis and Biological Evaluation of N‐aryl‐4‐aryl‐1,3‐Thiazole‐2‐Amine Derivatives as Direct 5‐Lipoxygenase Inhibitors
Authors: Suh Jeehee , Yum Eul Kgun , Cheon Hyae Gyeong , Cho Young Sik
Published: March 2012

Biological evaluation of N‐aryl‐4‐aryl‐1,3‐thiazole‐2‐amine derivatives was examined for anti‐inflammatory activity in in vitro and in vivo assays. The thiazole compounds showed direct inhibition of 5‐lipoxygenase (LOX) that is a key enzyme of leukotrienes synthesis and involved in the inflammation‐related diseases, including asthma and rheumatoid arthritis. To optimize biological activity, we synthesized 1,3‐thiazole‐2‐amine derivatives and investigated for structure and activity relationship. Especially, N‐(3,5‐dimethylphenyl)‐4‐(4‐chlorophenyl)‐1,3‐thiazole‐2‐amine was shown to have a potent anti‐inflammatory activity as a 5‐LOX inhibitor.
Understanding the Relationship Between Photolysis Efficiency and Metal Binding Using ArgenCast Photocages
Authors: Mbatia Hannah W. , Kennedy Daniel P. , Burdette Shawn C.
Published: March 2012

ArgenCast‐1 (1), a photocage for silver utilizing acyclic polythioether 3,6,12,15‐tetrathia‐9‐azaheptadecane receptor and 4,5‐dimethoxy‐2‐nitrobenzyl (DMNB) chromophore has been prepared using trimethylsilyl trifluoromethanesulfonate‐assisted electrophilic aromatic substitution. Metal binding studies with ArgenCast‐1 reveal interactions with Ag+, Hg2+ and Cu+, but only Ag+ coordinates in both aqueous and organic solvents. The uncaging mechanism of ArgenCast‐1 metal complex involves a photoreaction that converts the nitrobenzydrol into the electron withdrawing nitrosobenzophenone that participates in a resonance interaction with a metal‐bound aniline nitrogen atom. The structural change following photolysis decreases availability of the nitrogen lone pair for Ag+ coordination, but strong interactions between Ag+ and the thioether ligands mitigates metal ion release. A resonance interaction with a key aci‐nitro intermediate reduces the photolysis quantum yield of ArgenCast‐1, so several naphthyl‐based nitrobenzyl groups were screened as alternatives to DMNB. The naphthyl Ag+ photocages, ArgenCast‐2 and ‐3, exhibit nearly identical quantum yield to ArgenCast‐1 owing to the dominance of resonance between aci‐nitro intermediate and the aniline nitrogen atom.
Enantioselective drug–protein interaction between mexiletine and plasma protein
Authors: Yu Lushan , Hong Yanjun , Li Li , Jin Yingxiu , Zheng Mingyue , Jiang Hualiang , Zeng Su
Published: March 2012

Objectives

This study examined the interaction of mexiletine enantiomers with human plasma, human serum albumin (HSA), and human α1-acid glycoprotein (hAGP), and characterized the binding modes of mexiletine enantiomers with hAGP in the molecular level.

Methods

Enantiomer separation of mexiletine was performed using precolumn derivatization chiral HPLC. The ultrafiltration technique was used to separate the free mexiletine in plasma matrix. Molecular dynamics simulations and free energy calculations were assessed using molecular mechanics and the generalized Born surface area method.

Key findings

Significant differences in enantioselective binding to human plasma were observed (R > S). The hAGP–mexiletine binding profile exhibited similar enantioselectivity (R > S) to that in human plasma, whereas HSA–mexiletine interaction was S > R at pH 7.4. Moreover, the results of comparative studies indicated that mexiletine had the highest binding affinity for F1-S, a variant of hAGP. Based on the computational studies, residues such as Arg90, Leu79, Ser89 and Phe89 showed an energy difference of more than −0.35 kcal/mol between the enantiomers.

Conclusions

hAGP may be one of the key proteins leading to the enantioselective protein bindings of mexiletine in human plasma (R > S). The residues Arg90, Leu79, Ser89 and Phe89 of hAGP may have important roles in the observed enantioselectivity.
Implementation of Wireless Temperature Sensors for Continuous Condition Monitoring of Railroad Bearings
Authors: Kypuros Javier A. , Tarawneh Constantine M. , Zagouris Andoni , Woods Sean , Wilson Brent M. , Martin Andrew
Published: March 2012

At present there are no existing bearing health monitoring systems capable of continuous monitoring and tracking of railroad bearings on freight cars. Current wayside equipment is used to garner intermittent bearing cup temperatures, which at times could be every 65 km (∼40 mi) or more. Such devices are not designed to provide continuous condition monitoring which would enable users to assess the rate of bearing health degradation and predict when a bearing will require service. To this end, IONX, LLC, a subsidiary of Amsted Rail, Inc., has developed low power Wireless Sensor Nodes (WSNs) which can be retrofitted to existing bearing adapters. The WSNs provide continuous monitoring of bearing temperatures as well as the current ambient temperature. Since the nodes are affixed to the bearing adapter surface, a correlation is necessary to estimate the bearing cup temperature using the measured adapter surface temperature. This paper describes research conducted at The University of Texas-Pan American (UTPA) to devise a reliable mathematical model to correlate both temperatures. Additionally, these wireless nodes are currently in use on ten railroad cars that are part of an Australian fleet. The nodes have been collecting data since March 2010. The acquired data was used to devise and test a series of metrics that can automatically detect distressed bearings and predict time to maintenance. The development of bearing health monitoring metrics and their use to assess bearings in the Australian fleet is also discussed in this paper.
Energy Harvesting Systems to Power Onboard Railroad Equipment
Authors: Nagode C. , Ahmadian M. , Taheri S.
Published: March 2012

A practical and innovative solution to answer the need for power in freight cars is presented. The lack of available electric power in the vast majority of freight cars limits the use of electronic devices such as measuring (sensor) systems, GPS tracking devices or active RFID tags. An energy harvesting system has been developed to keep a battery charged and electric equipment running. The basic idea is to generate power using the relative motion of the car suspension as an input, scavenging energy that is normally wasted as heat in the damping system. Based on a promising first generation unit used as a proof of concept, the current prototype is designed to fit inside a typical suspension spring (D5) and so, can easily be implemented in virtually any rail car. During laboratory tests, the system is capable of efficiently generating up to 80W of power, on quasi-continuous basis, with a sinusoidal input of 3/8 inch at 2Hz. Durability tests have also been conducted to ensure that the system can withstand the harsh railroad environment. Additionally, actual suspension displacement measurements have been used to replicate real conditions and forge a more precise idea of the behavior that can be expected once implemented in a rail car. With encouraging laboratory tests, the next steps are to further validate the system and to confirm the obtained results with field testing.
Seattle Center Monorail Train Refurbishment Program
Authors: Donohue Brian P.
Published: March 2012

Long the iconic transportation symbol of Seattle, the monorail system was constructed for the 1962 World’s Fair. Seattle’s monorail vehicles were the last and most technically advanced vehicles designed and built by the firm of Alweg-Forschung, GmbH (Alweg) of Cologne, Germany. The primary train operating systems and components were supplied by major US transit system equipment vendors of that era, including G.E., WABCO, and Rockwell. The two, 4-car train’s original layout and function generally conformed to US transit rail equipment standards and design practices of the early 1960s. However, during 45-years of near-continuous, revenue operation that included upgrades, piecemeal refurbishment projects and accident/incident repairs, many changes were made to the original design with varying levels of success and documentation. In 2007, a small team of Seattle Monorail staff and consultants identified the vehicle systems and components that were most urgently in need of replacement or overhaul given the limited funding and time available for completion of design work, preparation of contractor bid documentation and construction. Project funding was primarily via a grant from the Federal Transit Administration (FTA), supplemented by the City of Seattle. The historical significance of the Seattle Monorail was at the center of the refurbishment program, with great care in functional design, aesthetics and construction being exercised throughout the program until completion in 2010. The modernization included the installation and integration of: communications-based train control; programmable logic controllers (PLC’s) for auxiliary systems; redundancy and interlocking of key safety-related components; streamlined controls that lead to significant weight savings and increased reliability; modern components to address ADA compliance; and ergonomic Driver Cabs. This report discusses the Seattle Center Monorail Refurbishment Program given the unique opportunity to modernize two historic pieces of transportation rolling stock that is anticipated to run in revenue service for the next 45 years.
The Process of Spalling in Railroad Wheels
Authors: Dedmon Steven L.
Published: March 2012

Although the term “Spalling” means different things to different disciplines and product types, for railroad wheels the term is used for the process by which tread cracks form as a result of a sliding event. The process includes rapid heating and austenitizing of the tread surface during a slide followed by rapid cooling and transformation to untempered martensite. Preexisting cracks in the area of a slide can grow from shallow and harmless cracks into cracks of greater significance due to high thermal and transformation stresses. Case crushing of the tread caused by high loads can also develop into spalls. Lastly, rolling contacts can cause fatigue cracks to form at the edges of a martensite patch in the heat affected zone. A complex combination of lower material strength and higher residual and applied stresses and the limiting hardenability of carbon steel produce conditions ideal for the formation of fatigue cracks. This investigation uses finite element analyses and laboratory tests to characterize the process of spalling.
Freight Car Electrically Driven Set and Release Hand Brake (EDHB)
Authors: Brabb David C. , Martin Kenneth L. , Vithani Anand R. , Stewart Monique F. , Punwani S. K.
Published: March 2012

For years, American freight railroads have attempted to eliminate freight train crew injuries when applying and releasing freight car hand brakes. Currently, a person has to crank a handle or turn a wheel while in ergonomically awkward positions to apply a hand brake. If the operator slips or the brake’s mechanisms slip, injuries occur. Also, there are inherent safety issues with the climbing of ladders or steps to operate the brake and the need for going in-between cars to access the brakes. Additionally, today’s hand brakes are applied manually to varying degrees because there is no indicator to tell the crew that the hand brake is fully applied. Many times the hand brake is over applied and becomes damaged. Moreover, a hand brake that is not released upon train movement leads to wheel flats that damage the car, lading, and the track. Wheel set replacement is one of the most costly remediation activities on the railroad and damaged track adversely affects equipment and operations. With the objective of reducing or completely eliminating the issues mentioned above, the Federal Railroad Administration (FRA) has sponsored the development of an ‘Electrically Driven Set & Release Hand Brake’ (EDHB). Under this effort, Sharma & Associates, Inc. (SA) has conducted research into related concepts/products conceptualized and evaluated different arrangements selected a promising concept and developed a prototype. Functional laboratory demonstration tests have been conducted on the prototype. Future plans include working with the industry in developing and implementing performance and testing specifications for the EDHB, and validating the design through lab and field-testing.
Experimenting with Politics
Authors: Druckman James N. , Lupia Arthur
Published: March 2012

Social scientists are turning increasingly to experiments to explain important political behaviors.
Coking- and Sintering-Resistant Palladium Catalysts Achieved Through Atomic Layer Deposition
Authors: Lu Junling , Fu Baosong , Kung Mayfair C. , Xiao Guomin , Elam Jeffrey W. , Kung Harold H. , Stair Peter C.
Published: March 2012

A Useful Cover-Up

Many industrial catalysts that consist of metal nanoparticles adsorbed on metal oxide supports undergo deactivation after prolonged use. Organic reactants can decompose and cover the metal with carbon (“coking”), and other processes can push the size distribution to fewer but larger particles that have less overall surface area available for reaction (“sintering”).

Lu
et al.

(p.
1205
) used atomic-layer deposition to apply a uniform overlayer of alumina onto supported palladium nanoparticles. This coating greatly increased the resistance of the nanoparticles to coking and sintering during the oxidative dehydration of ethane to ethylene.
Isolated Metal Atom Geometries as a Strategy for Selective Heterogeneous Hydrogenations
Authors: Kyriakou Georgios , Boucher Matthew B. , Jewell April D. , Lewis Emily A. , Lawton Timothy J. , Baber Ashleigh E. , Tierney Heather L. , Flytzani-Stephanopoulos Maria , Sykes E. Charles H.
Published: March 2012

Tuning Hydrogen Adsorption

Heterogeneous metal catalysts for hydrogenating unsaturated organic compounds need to bind molecular hydrogen strongly enough that it dissociates and forms adsorbed hydrogen atoms, but must not bind these atoms too strongly, or the transfer to the organic molecule will be impeded.

Kyriakou
et al.

(p.
1209
) examined surface alloy catalysts created when palladium (Pd) atoms are adsorbed on a copper (Cu) surface using scanning tunneling microscopy and desorption techniques under ultrahigh vacuum conditions. The Pd atoms could bind hydrogen dissociatively—which, under these conditions, the Cu surfaces could not—allowing the Cu surface to take up adsorbed hydrogen atoms. These weakly bound hydrogen atoms were able to selectively hydrogenate styrene and acetylene.
Worldwide Lessons from 11 March
Authors: Omi Koji
Published: March 2012

It has been 1 year since a devastating earthquake and tsunami struck the northeast coast of Japan, a disaster that continues to be analyzed by many people around the world, from different perspectives. There are important lessons to be learned as Japan faces critical decisions not only about rebuilding but also in planning for the nation's future energy needs—lessons that are also relevant to many other countries.
Light in the Deep
Authors: Pennisi Elizabeth
Published: March 2012

From fish to squid, marine creatures have evolved sophisticated ways to make, use, and perceive light, inspiring researchers interested in optics and animal ecology and behavior.
One Year After the Devastation, Tohoku Designs Its Renewal
Authors: Normile Dennis
Published: March 2012

Taking stock of the 11 March 2011 earthquake and tsunami, experts are planning communities that should be more resilient the next time disaster strikes.
Influenza Viruses Expressing Chimeric Hemagglutinins: Globular Head and Stalk Domains Derived from Different Subtypes
Authors: Hai Rong , Krammer Florian , Tan Gene S. , Pica Natalie , Eggink Dirk , Maamary Jad , Margine Irina , Albrecht Randy A. , Palese Peter
Published: March 2012

The influenza virus hemagglutinin molecule possesses a globular head domain that mediates receptor binding and a stalk domain at the membrane-proximal region. We generated functional influenza viruses expressing chimeric hemagglutinins encompassing a variety of globular head and stalk combinations, not only from different hemagglutinin subtypes but also from different hemagglutinin phylogenetic groups. These chimeric recombinant viruses possess growth properties similar to those of wild-type influenza viruses and can be used as reagents to measure domain-specific antibodies in virological and immunological assays.
Superinfection Exclusion Is an Active Virus-Controlled Function That Requires a Specific Viral Protein
Authors: Folimonova Svetlana Y.
Published: March 2012

Superinfection exclusion, a phenomenon in which a preexisting viral infection prevents a secondary infection with the same or a closely related virus, has been described for various viruses, including important pathogens of humans, animals, and plants. The phenomenon was initially used to test the relatedness of plant viruses. Subsequently, purposeful infection with a mild isolate has been implemented as a protective measure against virus isolates that cause severe disease. In the medical and veterinary fields, superinfection exclusion was found to interfere with repeated applications of virus-based vaccines to individuals with persistent infections and with the introduction of multicomponent vaccines. In spite of its significance, our understanding of this phenomenon is surprisingly incomplete. Recently, it was demonstrated that superinfection exclusion of
Citrus tristeza virus
(CTV), a positive-sense RNA closterovirus, occurs only between isolates of the same strain, but not between isolates of different strains of the virus. In this study, I show that superinfection exclusion by CTV requires production of a specific viral protein, the p33 protein. Lack of the functional p33 protein completely eliminated the ability of the virus to exclude superinfection by the same or a closely related virus. Remarkably, the protein appeared to function only in a homology-dependent manner. A cognate protein from a heterologous strain failed to confer the exclusion, suggesting the existence of precise interactions of the p33 protein with other factors involved in this complex phenomenon.