bluuebunny/crossref_metadata_2025 huggingface dataset:
The use of angiogenic‐antimicrobial agents in experimental wounds in animals: problems and solutions
Authors: Suman Paritosh , Ramachandran Harikrishnan , Sahakian Sossy , Gill Kamraan Z. , Horst Basil A. J. , Modak Shanta M. , Hardy Mark A.
Published: October 2012

A topical combination (silvathymosin) of natural proangiogeneic protein thymosin β4 (Tβ4) and antimicrobial silver sulfadiazine was hypothesized to promote the healing of large, full‐thickness, clean or infected wounds in rats. Silvathymosin showed the fastest wound healing (85%) followed by silver sulfadiazine (84%) and Tβ4 (72%). In the infected groups, the healing pattern was different, as Tβ4 and silvathymosin groups did not show similar wound healing. Wound histopathology and VEGF and KI67 immunohistochemical assessment of angiogenesis was consistent and correlated well with the tempo of healing of the acute wounds. These preliminary data demonstrate the more rapid acute wound healing properties of the combination formulation of thymosin β4 and silver sulfadiazine as compared to these agents alone. This novel agent could prove an effective treatment modality for debilitating chronic wounds and decubitus ulcers.
Use of the cardioprotectants thymosin β4 and dexrazoxane during congenital heart surgery: proposal for a randomized, double‐blind, clinical trial
Authors: Stromberg Daniel , Raymond Tia , Samuel David , Crockford David , Stigall William , Leonard Steven , Mendeloff Eric , Gormley Andrew
Published: October 2012

Neonates and infants undergoing heart surgery with cardioplegic arrest experience both inflammation and myocardial ischemia‐reperfusion (IR) injury. These processes provoke myocardial apoptosis and oxygen‐free radical formation that result in cardiac injury and dysfunction. Thymosin β4 (Tβ4) is a naturally occurring peptide that has cardioprotective and antiapoptotic effects. Similarly, dexrazoxane provides cardioprotection by reduction of toxic reactive oxygen species (ROS) and suppression of apoptosis. We propose a pilot pharmacokinetic/safety trial of Tβ4 and dexrazoxane in children less than one year of age, followed by a randomized, double‐blind, clinical trial of Tβ4 or dexrazoxane versus placebo during congenital heart surgery. We will evaluate postoperative time to resolution of organ failure, development of low cardiac output syndrome, length of cardiac ICU and hospital stays, and echocardiographic indices of cardiac dysfunction. Results could establish the clinical utility of Tβ4 and/or dexrazoxane in ameliorating ischemia‐reperfusion injury during congenital heart surgery.
Cutaneous responses to environmental stressors
Authors: Valacchi Giuseppe , Sticozzi Claudia , Pecorelli Alessandra , Cervellati Franco , Cervellati Carlo , Maioli Emanuela
Published: October 2012

Living organisms are continuously exposed to environmental pollutants. Because of its critical location, the skin is a major interface between the body and the environment and provides a biological barrier against an array of chemical and physical environmental pollutants. The skin can be defined as our first defense against the environment because of its constant exposure to oxidants, including ultraviolet (UV) radiation and other environmental pollutants such as diesel fuel exhaust, cigarette smoke (CS), halogenated hydrocarbons, heavy metals, and ozone (O3). The exposure to environmental pro‐oxidant agents leads to the formation of reactive oxygen species (ROS) and the generation of bioactive molecules that can damage skin cells. This short review provides an overview of the effects and mechanisms of action of CS, O3, and UV on cutanous tissues.
The role of biologically active peptides in tissue repair using umbilical cord mesenchymal stem cells
Authors: Cabrera Carlos , Carriquiry Gabriela , Pierinelli Chiara , Reinoso Nancy , Arias‐Stella Javier , Paino Javier
Published: October 2012

The role of bioactive compounds in wound repair is critical. The preliminary work described herein includes the study of the effects of second degree burns in a Rex rabbit model and the action of human umbilical cord cells on the regulation and secretion of bioactive compounds. When applied on blood scaffolds as heterograft matrices, fibroblasts proliferate from these primary cultures and release biologically active peptides under tight control. Our work in progress indicates that mesenchymal stem cell (MSC)–mediated therapy provides better quality and more efficient burn reepithelialization of injured tissues by controlling the release of these peptides. Improvement of wound aesthetics is achieved in less time than without MSC‐mediated therapy. Well‐organized epidermal regeneration and overall better quality of reepithelialization, with no rejection, can be demonstrated consistently with periodic biopsies. Our studies indicate that MSCs have the capacity to produce, regulate, and deliver biologically active peptides that result in superior regeneration, compared with conventional treatments.
Role of PGC‐1α signaling in skeletal muscle health and disease
Authors: Kang Chounghun , Li Ji Li
Published: October 2012

This paper reviews the current understanding of the molecular basis of the peroxisome proliferator‐activated receptor‐γ coactivator‐1α (PGC‐1α)–mediated pathway and discusses the role of PGC‐1α in skeletal muscle atrophy caused by immobilization. PGC‐1α is the master transcription regulator that stimulates mitochondrial biogenesis, by upregulating nuclear respiratory factors (NRF‐1, 2) and mitochondrial transcription factor A (Tfam), which leads to increased mitochondrial DNA replication and gene transcription. PGC‐1α also regulates cellular oxidant–antioxidant homeostasis by stimulating the gene expression of superoxide dismutase‐2 (SOD2), catalase, glutathione peroxidase 1 (GPx1), and uncoupling protein (UCP). Recent reports from muscle‐specific PGC‐1α overexpression underline the importance of PGC‐1α in atrophied skeletal muscle, demonstrate enhancement of the PGC‐1α mitochondrial biogenic pathway, and reduced oxidative damage. Thus, PGC‐1α appears to play a protective role against atrophy‐linked skeletal muscle deterioration.
Obesity and cancer risk: evidence, mechanisms, and recommendations
Authors: Vucenik Ivana , Stains Joseph P.
Published: October 2012

Obesity, a growing health problem worldwide, has been associated with the metabolic syndrome, diabetes, cardiovascular disease, hypertension, and other chronic diseases. Recently, the obesity–cancer link has received much attention. Epidemiological studies have shown that obesity is also associated with increased risk of several cancer types, including colon, breast, endometrium, liver, kidney, esophagus, gastric, pancreatic, gallbladder, and leukemia, and can also lead to poorer treatment and increased cancer‐related mortality. Biological mechanisms underlying the relationship between obesity and cancer are not well understood. They include modulation of energy balance and calorie restriction, growth factors, multiple signaling pathways, and inflammatory processes. Key among the signaling pathways linking obesity and cancer is the PI3K/Akt/mTOR cascade, which is a target of many of the obesity‐associated factors and regulates cell proliferation and survival. Understanding the molecular and cellular mechanisms of the obesity–cancer connection is important in developing potential therapeutics. The link between obesity and cancer underscores the recommendation to maintain a healthy body weight throughout life as one of the most important ways to protect against cancer.
Mechanism of Hydrolysis of Native and Cooked Starches from Different Botanical Sources in the Presence of Tea Extracts
Authors: Guzar Igor , Ragaee Sanaa , Seetharaman Koushik
Published: October 2012

Abstract:  A series of experiments were conducted to highlight the mechanism of inhibition of hydrolysis and differences in hydrolysis among starches from different sources in the presence of green or black tea extract. The first experiment showed that black tea extract was more effective at reducing final viscosity for all starches. The second experiment showed that black tea was more effective at inhibiting starch hydrolysis compared to green tea when starch, tea extract, and pancreatin were added at the beginning of pasting. The third experiment, when starches were pretreated with tea extracts, showed that both treatments reduced starch hydrolysis. Analysis of supernatant free phenolic content and of soluble dextrins showed that amyloglucosidase activity was affected, with exceptions for potato starch. These observations suggest that starch hydrolysis is affected by interactions and also by the impact on specific enzymes based on starch structure.
Textural Characteristic, Antioxidant Activity, Sugar, Organic Acid, and Phenolic Profiles of 10 Promising Jujube (Ziziphus jujuba Mill.) Selections
Authors: Gao Qing‐Han , Wu Chun‐Sen , Yu Jin‐Gang , Wang Min , Ma Yu‐Jie , Li Cui‐Li
Published: October 2012

Abstract:  Ten promising jujubes were analyzed for textural characteristic (hardness), antioxidant activity, sugar, organic acid, and phenolic profiles. Total phenolic content (TP) measured by Folin–Ciocalteu method ranged from 275.6 to 541.8 mg of gallic acid equivalents per 100 g fresh weight (mg GAE/100 g FW). Four sugars (rhamnose, fructose, sucrose, and glucose), 3 organic acids (malic, citric, and succinic acids), and 11 phenolic compounds (gallic acid, protocatechuic acid, cinnamic acid, chlorogenic acid, caffeic acid, ferulic acid, ellagic acid, catechin, epicatechin, rutin, and quercetin) were identified and quantified by high‐performance liquid chromatography in jujube fruits. The results showed that ascorbic acid and proanthocyanidins contents were positively correlated with hardness, and antioxidant activity was well correlated with TP content. Among 10 jujube cultivars, Zizyphus jujuba cv. Qingjianmuzao is good for direct consumption containing high levels of total soluble solids, total sugars, fructose, and glucose, while Zizyphus jujuba cv. Jiaxianmuzao could be an important dietary source of natural antioxidants.

Practical Application:  Genotype is the main factor influencing the composition of bioactive compounds in jujubes. Zizyphus jujuba cv. Qingjianmuzao is good for direct consumption, while Zizyphus jujuba cv. Jiaxianmuzao could be an important dietary source of natural antioxidants for prevention of diseases caused by oxidative stress.
Comparison of the pharmacokinetics of three concentrations of insulin aspart during continuous subcutaneous insulin infusion (CSII) in a pig model
Authors: Petersen Signe Beck , Nielsen Flemming Seier , Ribel Ulla , Sturis Jeppe , Skyggebjerg Ole
Published: October 2012

Objectives

The aim of the study was to investigate the pharmacokinetic properties of insulin aspart (IAsp) in three different concentrations given as a continuous subcutaneous insulin infusion (CSII).

Methods

A randomized cross-over study was performed in pigs, where IAsp U200, U100 or U20 was given for 8 h with the same total dose. Six pigs were included and blood was sampled during the CSII and 3 h after.

Key findings

The half-life (t1/2) was 24.3 (range 17.3–41.3), 28.8 (range 19.6–54.3) and 23.6 (range 17.4–36.8) min for U200, U100 and U20, respectively. The area under the curve per dose (AUC/D) was determined to be 51.2 ± 19.5, 52.3 ± 12.5 and 51.6 ± 6.7 pm × min/kg for U200, U100 and U20, respectively. The steady state plasma concentration (Css) was 57.5 ± 27.1, 54.3 ± 10.3 and 55.1 ± 8.0 pm (mean ± SD) for U200, U100 and U20, respectively. Time to steady state (Tss) was 110 ± 36, 98 ± 48 and 90 ± 27 min for U200, U100 and U20, respectively.

Conclusions

In conclusion, no significant difference was found in t1/2, AUC/D, Css or Tss between the three IAsp concentrations when given at a basal rate in CSII.
Adolescent Depression: Meeting Therapeutic Challenges Through an Integrated Narrative Approach
Authors: Bennett Lorna Ruth
Published: October 2012

Topic

The adolescent period is a time of transition and change often associated with losses and adjustment issues at the family, school, and individual levels. When this normal developmental transition is interrupted and compounded by depressive illness, treatment needs and nursing therapeutic challenges can be daunting.

Purpose

This clinically based article explores the clinical process and progress in work with a 14‐year‐old adolescent boy who was diagnosed with a major depressive episode. Core clinical features, distinguishing characteristics of depression in youth, as well as specific therapeutic issues and challenges are discussed. The value of an integrated clinical approach with special emphasis on narrative methods both for achievement of clinical goals and for establishing a therapeutic alliance is highlighted.

Sources Used

The study used published literature and the author's professional and clinical experiences.

Conclusion

Nursing therapeutics with adolescents experiencing depression must embrace a holistic integrated approach to adolescent recovery with an emphasis on what works with each unique clinical situation. Special attention to the nurse–adolescent therapeutic alliance not only facilitates achievement of therapeutic goals related to the depressive illness, but in addition, supports the shaping of a new self‐narrative, wholeness, and healthy adolescent development and well‐being.
A Pilot Program to Address Healthy Sexual Behaviors Among Girls in Juvenile Detention
Authors: Herrman Judith W. , Waterhouse Julie K.
Published: October 2012

Purpose

This pilot study was designed to determine the effectiveness of an intervention on sexual behavior among girls in juvenile detention.

Methods

The pre/posttest model assessed for changes in knowledge, attitudes, and reported behaviors. This program merged three curricula to create the unique Young Women Get Real Program with nursing student program facilitators.

Findings

Despite high levels of satisfaction with the program, the data related to the final sample (n = 35) failed to reveal significant changes in measured variables.

Conclusions

The results may inform nurses as they pursue interventions to promote responsible sexual behavior in selected populations.
Childhood Predictors of Adolescent Competence and Self‐Worth in Rural Youth
Authors: Rew Lynn , Grady Matthew W. , Spoden Micajah
Published: October 2012

Problem

Urban children who become competent adults despite circumstances that place their development and mental health at risk are considered to be resilient. Less is known about the risk and protective factors that characterize resilience among Hispanic/Latinos living in rural areas.

Methods

Data for regression analyses were collected when children (n = 603; 54% Hispanic/Latino) enrolled in the study in fifth grade (M = 10.4 years of age), and again 5 years later when they were in high school (M = 15 years of age).

Findings

Statistically significant predictors of competence and self‐worth in high schoolers included gender, ethnicity, and mother's education, as well as stress, temperament (task persistence), and competences measured in grade school.

Conclusions

Parents' perception of child's temperament is a significant predictor of future competence and self‐worth among rural adolescents.
Emergence of 13_A2 Blue Lineage of Phytophthora infestans was Responsible for Severe Outbreaks of Late Blight on Tomato in South‐West India
Authors: Chowdappa Pallem , Kumar Nirmal B. J. , Madhura Shivanna , Kumar Mohan S. P. , Myers Kevin L. , Fry William E. , Squires Julie N. , Cooke David E. L.
Published: October 2012

Prior to 2007, late blight was not reported as a serious threat to tomato cultivation in India although the disease has been known on potato since 1953. During the July–December cropping season of 2009 and 2010, severe late blight epidemics were observed in Karnataka state of India, causing crop losses up to 100%. Nineteen Phytophthora isolates, recovered from late blight affected tomato tissues from different localities in Karnataka state between 2009 and 2010, were identified as Phytophthora infestans based on morphology, a similarity search of ITS sequences at GenBank and species‐specific PCR using PINF/ITS5 primer pair. The isolates were further assessed for metalaxyl sensitivity, mating type, mitochondrial DNA (mtDNA) haplotype, DNA fingerprinting patterns based on simple sequence repeats (SSR) and RFLPs using the RG57 probe and aggressiveness on tomato. All isolates were metalaxyl resistant, A2 mating type, mtDNA haplotype Ia and had identical SSR and RG57 fingerprints and highly aggressive on tomato. The phenotypic and genotypic characters of isolates examined in this study were found to be similar to that of 13_A2 genotype of P. infestans population reported in Europe. Thus, appearance of new population similar to 13_A2 genotype was responsible for severe late blight epidemics on tomato in South‐West India.
Methods to quantify components of the excavating sponge Cliona orientalis Thiele, 1900
Authors: Fang James K. H. , Schönberg Christine H. L. , Kline David I. , Hoegh‐Guldberg Ove , Dove Sophie
Published: October 2012

This study applied the loss after combustion (LAC) method and the acid decalcification (ADC) method to quantify different components of an excavating sponge. Samples of dried coral skeleton of Favia sp. invaded by the Indo‐Pacific excavating sponge Cliona orientalis Thiele, 1900 were used. The sponge tissue penetrated the 12‐mm‐thick samples to approximately 10 mm. The average proportional weight of organic matter, siliceous spicules, calcareous substrate and salts in the entire samples was found to be respectively 2.5%, 4.4%, 90.5% and 2.5% of dry weight applying the LAC method, and 2.9%, 5.9%, 89.0% and 2.3% of dry weight applying the ADC method. Respective volumetric proportions of the organic matter, spicules, substrate and salts were then calculated to be 6.4%, 5.5%, 85.2% and 3.0% of volume with the LAC method, and 7.4%, 7.2%, 82.7% and 2.7% of volume with the ADC method. The LAC method showed low variability of data and is simple and fast and therefore is recommended. The ADC method generated very similar results to the LAC method. However, due to the handling involved in the ADC method, more than half of the spicules may be lost and the method is therefore not recommended unless careful data corrections are considered. In addition, the buoyant weight method was used to quantify actual substrate weight in the fresh sponge‐substrate samples. This method was found to be at least 97% effective, revealing that buoyant weights can potentially be used to quantify bioerosion rates of excavating sponges. To our knowledge, this is the first study to systemically quantify organic and inorganic components of an excavating sponge and its calcareous substrate, providing improved standard methods for future studies.
Incorporating latitudinal and central–marginal trends in assessing genetic variation across species ranges
Authors: Guo Qinfeng
Published: October 2012

The genetic variation across a species’ range is an important factor in speciation and conservation, yet searching for general patterns and underlying causes remains challenging. While the majority of comparisons between central and marginal populations have revealed a general central–marginal (C–M) decline in genetic diversity, others show no clear pattern. Similarly, most latitudinal studies (although much fewer, especially those conducted rangewide) also showed latitudinal trends in genetic variation. To date, theC–Mand latitudinal patterns have often been examined independently and have rarely been considered together when accounting for the observed genetic variation across species ranges. Here, in the light of the most recent findings, I show how latitude might be responsible for some of the deviations from the generalC–Mtrends in genetic diversity, and vice versa. In the future, integrating latitude and range geometry with climate‐induced species migration would offer important insights into conservation prioritization across species ranges.
The ecological and genetic basis of convergent thick‐lipped phenotypes in cichlid fishes
Authors: Colombo Marco , Diepeveen Eveline T. , Muschick Moritz , Santos M. EMILIA , Indermaur Adrian , Boileau Nicolas , Barluenga Marta , Salzburger Walter
Published: October 2012

The evolution of convergent phenotypes is one of the most interesting outcomes of replicate adaptive radiations. Remarkable cases of convergence involve the thick‐lipped phenotype found across cichlid species flocks in theEastAfricanGreatLakes. Unlike most other convergent forms in cichlids, which are restricted toEastAfrica, the thick‐lipped phenotype also occurs elsewhere, for example in theCentralAmericanMidasCichlid assemblage. Here, we use an ecological genomic approach to study the function, the evolution and the genetic basis of this phenotype in two independent cichlid adaptive radiations on two continents. We applied phylogenetic, demographic, geometric morphometric and stomach content analyses to anAfrican (Lobochilotes labiatus) and aCentralAmerican (Amphilophus labiatus) thick‐lipped species. We found that similar morphological adaptations occur in both thick‐lipped species and that the ‘fleshy’ lips are associated with hard‐shelled prey in the form of molluscs and invertebrates. We then used comparativeIlluminaRNAsequencing of thick vs. normal lip tissue inEastAfrican cichlids and identified a set of 141 candidate genes that appear to be involved in the morphogenesis of this trait. A more detailed analysis of six of these genes led to three strong candidates:Actb,Cldn7andCopb. The function of these genes can be linked to the loose connective tissue constituting the fleshy lips. Similar trends in gene expression betweenAfrican andCentralAmerican thick‐lipped species appear to indicate that an overlapping set of genes was independently recruited to build this particular phenotype in both lineages.
Germ banks affect the inference of past demographic events
Authors: Živković Daniel , Tellier Aurélien
Published: October 2012

Continuous progress in empirical population genetics based on the whole‐genome polymorphism data requires the theoretical analysis of refined models in order to interpret the evolutionary history of populations with adequate accuracy. Recent studies focus prevalently on the aspects of demography and adaptation, whereas age structure (for example, in plants via the maintenance of seed banks) has attracted less attention. Germ banking, that is, seed or egg dormancy, is a prevalent and important life‐history trait in plants and invertebrates, which buffers against environmental variability and modulates species extinction in fragmented habitats. Within this study, we investigate the combined effect of germ banking and time‐varying population size on the neutral coalescent and particularly derive the allele frequency spectrum under some simplifying assumptions. We then perform anABCanalysis using two simple demographic scenarios—a population expansion and an instantaneous decline. We demonstrate the appreciable influence of seed banks on the estimation of demographic parameters depending on the germination rate with biases scaled by the square of the germination rate. In the more complex case of a population bottleneck, which comprises an instantaneous decline and an expansion phase, ignoring information on the germination rate denies reliable estimates of the bottleneck parameters via the allelic spectrum. In particular, when seeds remain in the bank over several generations, recent expansions may remain invisible in the frequency spectrum, whereas ancient declines leave signatures much longer than in the absence of seed bank.
High prevalence of food sensitisation in young children with liver disease: a clue to food allergy pathogenesis?
Authors: Brown Chrysothemis , Haringman Natasha , Davies Charlotte , Gore Claudia , Hussain Munther , Mieli‐Vergani Giorgina , Vergani Diego , Warner John O. , Marks Stephen D. , Boyle Robert J.
Published: October 2012

Background

The pathogenesis of food allergy is not completely understood – animal models suggest hepatic mechanisms may be important for immune tolerance to orally ingested antigens, but there is little direct evidence for this in humans.

Objectives

We investigated whether there is an association between liver dysfunction or transplantation in young children and IgE sensitisation to food.

Methods

We evaluated paired pre‐ and post‐ liver transplant sera from children aged 0–36 months treated at a single centre during 2001–2008. Sera were assayed for total IgE and cow's milk, egg and peanut‐specific IgE. We quantified hepatic dysfunction pre‐transplant using the Paediatric End‐stage Liver Disease (PELD) score. We also assessed 70 children after renal transplant to establish whether any association between liver transplant and food sensitisation was organ specific.

Results

Paired sera were available from 50 of 94 children who had a liver transplant during the study period. 35 of 50 (70%) had IgE sensitisation (≥0.35 kUa/l) to ≥1 food pre‐transplant and 18 (36%) post‐transplant (p = 0.001). Ten (20%) children had food‐specific IgE levels that carry high probability of challenge‐confirmed food allergy pre‐transplant. Food sensitisation pre‐transplant was associated with severity of liver dysfunction [mean (s.d.) pre‐transplant PELD score 1.52 (0.13) in food sensitised, 0.77 (0.22) in non‐sensitised children p = 0.004]. Total IgE level was raised in 34/42 (81%) pre‐transplant and fell significantly post‐transplant. Interview assessment of the parents of 40 children revealed that 13 (33%) had a history consistent with food allergy. These findings were not replicated in the renal transplant group.

Conclusions

Young children with severe liver dysfunction appear to have a high prevalence of food sensitisation. Hepatic mechanisms may therefore be important for establishing immune tolerance to dietary antigens in humans.
Leaf responses to drought stress in Mediterranean accessions of Solanum lycopersicum: anatomical adaptations in relation to gas exchange parameters
Authors: GALMÉS JERONI , OCHOGAVÍA JOAN MANUEL , GAGO JORGE , ROLDÁN EMILIO JOSÉ , CIFRE JOSEP , CONESA MIQUEL ÀNGEL
Published: October 2012

In a previous study, important acclimation to water stress was observed in the Ramellet tomato cultivar (TR) from the Balearic Islands, related to an increase in the water‐use efficiency through modifications in both stomatal (gs) and mesophyll conductances (gm). In the present work, the comparison of physiological and morphological traits between TR accessions grown with and without water stress confirmed that variability in the photosynthetic capacity was mostly explained by differences in the diffusion of CO2 through stomata and leaf mesophyll. Maximization of gm under both treatments was mainly achieved through adjustments in the mesophyll thickness and porosity and the surface area of chloroplasts exposed to intercellular airspace (Sc). In addition, the lower gm/Sc ratio for a given porosity in drought‐acclimated plants suggests that the decrease in gm was due to an increased cell wall thickness. Stomatal conductance was also affected by drought‐associated changes in the morphological properties of stomata, in an accession and treatment‐dependent manner. The results confirm the presence of advantageous physiological traits in the response to drought stress in Mediterranean accessions of tomato, and relate them to particular changes in the leaf anatomical properties, suggesting specific adaptive processes operating at the leaf anatomical level.
Concept of “awake venovenous extracorporeal membrane oxygenation” in pediatric patients awaiting lung transplantation
Authors: Schmidt F. , Sasse M. , Boehne M. , Mueller C. , Bertram H. , Kuehn C. , Warnecke G. , Ono M. , Seidemann K. , Jack T. , Koeditz H.
Published: October 2012

In patients awaiting LuTx, MV and ECMO are often the last ways to create a bridge to LuTx. Both interventions are associated with a poor posttransplant outcome and survival rate. To improve the results of these patients, new “bridging‐strategies” are necessary. Recent reports demonstrate promising results for the concept of “awake ECMO” in adult patients. To date, no data on this approach in pediatric patients have been available. We therefore describe the use of VV‐ECMO as a treatment strategy for RF in awake pediatric patients. It presents our experiences with the first three children treated using this new concept. Mean amount of time on ECMO was 44 days (range, 11.5–109 days). Two patients were successfully bridged to their LuTx. Both are still alive without any recurrences (24 and three months following LuTx). One patient died before a further LuTx after 109 days on ECMO due to adenoviral infection. Although reintubation was necessary in two patients, and total time being awake while on ECMO was <50%, we conclude that the concept of “awake VV‐ECMO” is feasible for the treatment of RF and can be used as a “bridging therapy” to LuTx.
Impact of Demographic Change, Socioeconomics, and Health Care Resources on Life Expectancy in Cambodia, Laos, and Myanmar
Authors: Chan Moon Fai , Taylor Beverly Joan
Published: October 2012

Objectives

Demographic and socioeconomic changes and the availability of health care resources were collected to examine the impacts on life expectancy in Cambodia, Laos, and Myanmar.

Design and Sample

An ecological design collecting 29 years (1980–2008) data for three Southeast Asian countries.

Measures

Life expectancy, demographics, socioeconomic status, and health care resources were collected.

Results

The structural equation model indicates that more available health care resources and socioeconomic advantages were more likely to increase life expectancy. By contrast, demographic change was more likely to increase life expectancy by way of health care resources.

Conclusions

Results show that factors that had direct impacts on life expectancy in all three countries were socioeconomic status and health care resources. Demographic changes had an indirect influence on life expectancy via health care resources. These findings suggest that policymakers should be focusing on how to remove the barriers that impede access to health care services during economic downturns. In addition, how to increase preventive care for the populations that have less access to health care in communities.
The linkage principle for restricted critical level representations of affine Kac–Moody algebras
Authors: Arakawa Tomoyuki , Fiebig Peter
Published: October 2012

We study the restricted category 𝒪 for an affine Kac–Moody algebra at the critical level. In particular, we prove the first part of the Feigin–Frenkel conjecture: the linkage principle for restricted Verma modules. Moreover, we prove a version of the Bernstein–Gelfand–Gelfand-reciprocity principle and we determine the block decomposition of the restricted category 𝒪. For the proofs, we need a deformed version of the classical structures, so we mostly work in a relative setting.
Computational Fluid Dynamics of a Radial Compressor Operating With Supercritical CO2
Authors: Pecnik Rene , Rinaldi Enrico , Colonna Piero
Published: October 2012

The merit of using supercritical CO2(scCO2) as the working fluid of a closed Brayton cycle gas turbine is now widely recognized, and the development of this technology is now actively pursued. scCO2 gas turbine power plants are an attractive option for solar, geothermal, and nuclear energy conversion. Among the challenges that must be overcome in order to successfully bring the technology to the market is that the efficiency of the compressor and turbine operating with the supercritical fluid should be increased as much as possible. High efficiency can be reached by means of sophisticated aerodynamic design, which, compared to other overall efficiency improvements, like cycle maximum pressure and temperature increase, or increase of recuperator effectiveness, does not require an increase in equipment cost, but only an additional effort in research and development. This paper reports a three-dimensional computational fluid dynamics (CFD) study of a high-speed centrifugal compressor operating with CO2 in the thermodynamic region slightly above the vapor–liquid critical point. The investigated geometry is the compressor impeller tested in the Sandia scCO2 compression loop facility. The fluid dynamic simulations are performed with a fully implicit parallel Reynolds-averaged Navier–Stokes code based on a finite volume formulation on arbitrary polyhedral mesh elements. In order to account for the strongly nonlinear variation of the thermophysical properties of supercritical CO2, the CFD code is coupled with an extensive library for the computation of properties of fluids and mixtures. A specialized look-up table approach and a meshing technique suited for turbomachinery geometries are also among the novelties introduced in the developed methodology. A detailed evaluation of the CFD results highlights the challenges of numerical studies aimed at the simulation of technically relevant compressible flows occurring close to the liquid–vapor critical point. The data of the obtained flow field are used for a comparison with experiments performed at the Sandia scCO2 compression-loop facility.
Understanding the Acoustic Oscillations Observed in the Injection Rate of a Common-Rail Direct Injection Diesel Injector
Authors: Manin Julien , Kastengren Alan , Payri Raul
Published: October 2012

Measuring the rate of injection of a common-rail injector is one of the first steps for diesel engine development. The injected quantity as a function of time is of prime interest for engine research and modeling activities, as it drives spray development and mixing, which, in current diesel engines, control combustion. On the other hand, the widely used long-tube method provides results that are neither straightforward nor fully understood. This study, performed on a 0.09-mm axially drilled single-hole nozzle, is part of the Engine Combustion Network (ECN) and aims at analyzing the acoustic oscillations observed in the rate of injection signal and measuring their impact on the real injection process and on the results recorded by the experimental devices. Several tests have been carried out for this study, including rate of injection and momentum, X-ray phase-contrast of the injector, and needle motion or injector displacement. The acoustic analysis revealed that these fluctuations found their origin in the sac of the injector and that they were the results of an interaction between the fluid in the chamber (generally gases) or in the nozzle sac and the liquid fuel to be injected. It has been observed that the relatively high oscillations recorded by the long-tube method were mainly caused by a displacement of the injector itself while injecting. In addition, the results showed that these acoustic features are also present in the spray, which means that the oscillations make it out of the injector, and that this temporal variation must be reflected in the actual rate of injection.
Life Prediction for Turbopropulsion Systems Under Dwell Fatigue Conditions
Authors: Chan Kwai S. , Enright Michael P. , Moody Jonathan P. , Hocking Benjamin , Fitch Simeon H. K.
Published: October 2012

The objective of this investigation was to develop an innovative methodology for life and reliability prediction of hot-section components in advanced turbopropulsion systems. A set of three generic time-dependent crack growth models was implemented and integrated into the Darwin® probabilistic life-prediction code. Using the enhanced risk analysis tool and material constants calibrated to IN 718 data, the effect of time-dependent crack growth on the risk of fracture in a turboengine component was demonstrated for a generic rotor design and a realistic mission profile. The results of this investigation confirmed that time-dependent crack growth and cycle-dependent crack growth in IN 718 can be treated by a simple summation of the crack increments over a mission. For the temperatures considered, time-dependent crack growth in IN 718 can be considered as a K-controlled environmentally-induced degradation process. Software implementation of the generic time-dependent crack growth models in Darwin provides a pathway for potential evaluation of the effects of multiple damage modes on the risk of component fracture at high service temperatures.
Impact of Swirl Flow on the Cooling Performance of an Effusion Cooled Combustor Liner
Authors: Wurm B. , Schulz A. , Bauer H.-J. , Gerendas M.
Published: October 2012

An experimental study on combustor liner cooling of modern direct lean injection combustion chambers using coolant ejection from both effusion cooling holes and a starter film has been conducted. The experimental setup consists of a generic scaled three sector planar rig in an open loop hot gas wind tunnel, which has been described earlier in Wurm et al. (2009, “A New Test Facility for Investigating the Interactions Between Swirl Flow and Wall Cooling Films in Combustors, Investigating the Interactions Between Swirl Flow and Wall Cooling Films in Combustors,” ASME Paper No. GT2009-59961). Experiments are performed without combustion. Realistic engine conditions are achieved by applying engine-realistic Reynolds numbers, Mach numbers, and density ratios. A particle image velocimetry (PIV) measurement technique is employed, which has been adjusted to allow for high resolution near wall velocity measurements with and without coolant ejection. As the main focus of the present study is a deeper understanding of the interaction of swirl flows and near wall cooling flows, wall pressure measurements are performed for the definition of local blowing ratios and to identify the impact on the local cooling performance. For thermal investigations an infrared thermography measurement technique is employed that allows high resolution thermal studies on the effusion cooled liner surface. The effects of different heat shield geometry on the flow field and performance of the cooling films are investigated in terms of near wall velocity distributions and film cooling effectiveness. Two different heat shield configurations are investigated which differ in shape and inclination angle of the so called heat shield lip. Operating conditions for the hot gas main flow are kept constant. The pressure drop across the effusion cooled liner is varied between 1% and 3% of the total pressure. Results show the impact of the swirled main flow on the stability of the starter film and on the effusion cooling performance. Stagnation areas which could be identified by wall pressure measurements are confirmed by PIV measurements. Thermal investigations reveal reduced cooling performance in the respective stagnation areas.
Large Eddy Simulations of Supersonic Impinging Jets
Authors: Erwin James P. , Sinha Neeraj , Rodebaugh Gregory P.
Published: October 2012

Supersonic impinging jet flow fields contain self-sustaining acoustic feedback features that create high levels of tonal noise. These types of flow fields are typically found with short takeoff and landing military aircraft as well as jet blast deflector operations on aircraft carrier decks. The United States Navy has a goal to reduce the noise generated by these impinging jet configurations and is investing in computational aeroacoustics to aid in the development of noise reduction concepts. In this paper, implicit large eddy simulation (LES) of impinging jet flow fields are coupled with a far-field acoustic transformation using the Ffowcs Williams and Hawkings (FW-H) equation method. The LES solves the noise generating regions of the flow and the FW-H transformation is used to predict the far-field noise. The noise prediction methodology is applied to a Mach 1.5 vertically impinging jet at a stand-off distance of five nozzle throat diameters. Both the LES and FW-H acoustic predictions compare favorably with experimental measurements. Time averaged and instantaneous flow fields are shown. A calculation performed previously at a stand-off distance of four nozzle throat diameters is revisited with adjustments to the methodology including a new grid, time integrator, and longer simulation runtime. The calculation exhibited various feedback loops which were not present before and can be attributed to an explicit time marching scheme. In addition, an instability analysis of the heated jets at both stand-off distances is performed. Tonal frequencies and instability modes are identified for the sample problems.
Design and Control of a Pneumatically Actuated Lower-Extremity Orthosis
Authors: Wu Sai-Kit , Driver Tad , Shen Xiangrong
Published: October 2012

Lower-extremity orthosis is a type of wearable mechanical device that serves a wide variety of important biomedical purposes, such as gait assistance and rehabilitative training. Due primarily to the constraints associated with actuation technology, the majority of current lower-extremity orthoses are either passive or tethered to external power sources, limiting the functionality of such devices. In this paper, the authors present the research results towards a fully mobile (i.e., untethered) powered lower-limb orthosis, leveraging the high power density of pneumatic actuators for the joint power generation. The design of the orthosis is presented, with the objectives of providing full locomotive assistance in multiple common locomotive modes and generating a minimum level of restriction to the wearer's daily activities. For the control of the orthosis, a finite-state impedance-based controller is developed, which simulates an artificial impedance in order to enable the natural interaction with the wearer. Preliminary testing on a healthy subject demonstrated that the orthosis was able to provide a natural gait and a comfortable user experience in the treadmill walking experiments.
Yield Characteristics of a Twill Dutch Woven Wire Mesh Via Experiments and Numerical Modeling
Authors: Kraft Steven M. , Gordon Ali P.
Published: October 2012

Woven structures are steadily emerging as excellent reinforcing components in composite materials. Metallic woven meshes, unlike most woven fabrics, show high potential for strengthening via classical methods such as heat treatment. Development of strengthening processes for metallic woven materials, however, must account not only for behavior of the constituent wires, but also for the interactions between contacting wires. Yield behavior of a 325 × 2300 stainless steel 316L (SS316L) twill dutch woven wire mesh is analyzed via experimental data and 3D numerical modeling. The effects of short dwell-time heat treatment on the mechanical properties of this class of materials is investigated via uniaxial tensile tests in the main weave orientations. Scanning electron microscopy (SEM) is employed to investigate the effects of heat treatment on contacting wire interaction, prompted by observations of reduced ductility in the macrostructure of the mesh. Finally, the finite element method (FEM) is used to simulate the accumulation of plastic deformation in the mesostructure of the mesh, investigating how this wire level plasticity ultimately affects global material yielding.
Hooke's Law and the Stiffness of a Plastic Spoon
Authors: Pestka Kenneth A. , Warren Cori
Published: October 2012

The study of elastic properties of solids is essential to both physics and engineering. Finding simple, easy-to-visualize examples to demonstrate these concepts is often difficult. In a previous article written by one of us (KAPII), a simple method for determining Youngs modulus using marshmallows was given.1 In this article we will illustrate another method to explore elastic properties of everyday materials. This experiment uses a common plastic spoon exposed to a transverse force in order to determine the stiffness constant, yield point, and rupture point of the plastic spoon. In addition, much like the “Youngs Modulus of a Marshmallow” activity, this experiment visually demonstrates Hooke's law, is fun and easy to perform, and leaves a lasting impression on the students.
Selective attention in an overcrowded auditory scene: Implications for auditory-based brain-computer interface design
Authors: Maddox Ross K. , Cheung Willy , Lee Adrian K. C.
Published: October 2012

Listeners are good at attending to one auditory stream in a crowded environment. However, is there an upper limit of streams present in an auditory scene at which this selective attention breaks down? Here, participants were asked to attend one stream of spoken letters amidst other letter streams. In half of the trials, an initial primer was played, cueing subjects to the sound configuration. Results indicate that performance increases with token repetitions. Priming provided a performance benefit, suggesting that stream selection, not formation, is the bottleneck associated with attention in an overcrowded scene. Results' implications for brain-computer interfaces are discussed.
Real time automatic detection of bearing fault in induction machine using kurtogram analysis
Authors: Tafinine Farid , Mokrani Karim
Published: October 2012

A proposed signal processing technique for incipient real time bearing fault detection based on kurtogram analysis is presented in this paper. The kurtogram is a fourth-order spectral analysis tool introduced for detecting and characterizing non-stationarities in a signal. This technique starts from investigating the resonance signatures over selected frequency bands to extract the representative features. The traditional spectral analysis is not appropriate for non-stationary vibration signal and for real time diagnosis. The performance of the proposed technique is examined by a series of experimental tests corresponding to different bearing conditions. Test results show that this signal processing technique is an effective bearing fault automatic detection method and gives a good basis for an integrated induction machine condition monitor.
Quantifying the Impact of Human Mobility on Malaria
Authors: Wesolowski Amy , Eagle Nathan , Tatem Andrew J. , Smith David L. , Noor Abdisalan M. , Snow Robert W. , Buckee Caroline O.
Published: October 2012

Mobile Phone “Hot Spots”

An obstacle to developing effective national malaria control programs is a lack of understanding of human movements, which are an important component of disease transmission. As mobile phones have become increasingly ubiquitous, it is now possible to collect individual-level, longitudinal data on human movements on a massive scale.

Wesolowski
et al.

(p.
267
) analyzed mobile phone call data records representing the travel patterns of 15 million mobile phone owners in Kenya over the course of a year. This was combined with a detailed malaria risk map, to estimate malaria parasite movements across the country that could be caused by human movement. This information enabled detailed analysis of parasite sources and sinks between hundreds of local settlements. Estimates were compared with hospital data from Nairobi to show that local pockets of transmission likely occur around the periphery of Nairobi, accounting for locally acquired cases, contrary to the accepted idea that there is no transmission in the capital.
Forces Driving Epithelial Spreading in Zebrafish Gastrulation
Authors: Behrndt Martin , Salbreux Guillaume , Campinho Pedro , Hauschild Robert , Oswald Felix , Roensch Julia , Grill Stephan W. , Heisenberg Carl-Philipp
Published: October 2012

Embryonic Cell Sorting and Movement

Differential cell adhesion has long been thought to drive cell sorting.

Maître
et al.

(p.
253
, published online 23 August) show that cell sorting in zebrafish gastrulation is triggered by differences in the ability of cells to modulate cortex tension at cell-cell contacts, thereby controlling contact expansion. Cell adhesion functions in this process by mechanically coupling the cortices of adhering cells at their contacts, allowing cortex tension to control contact expansion. In zebrafish epiboly the enveloping cell layer (EVL)—a surface epithelium formed at the animal pole of the gastrula—gradually spreads over the entire yolk cell to engulf it at the end of gastrulation.

Behrndt
et al.

(p.
257
) show that an actomyosin ring connected to the epithelial margin triggers EVL spreading both by contracting around its circumference and by generating a pulling force through resistance against retrograde actomyosin flow.