bluuebunny/crossref_metadata_2025 huggingface dataset:
Increasing Trend of Fatal Falls in Older Adults in the United States, 1992 to 2005: Coding Practice or Reporting Quality?
Authors: Kharrazi Rebekah J. , Nash Denis , Mielenz Thelma J.
Published: July 2015

Objectives

To investigate whether changes in death certificate coding and reporting practices explain part or all of the recent increase in the rate of fatal falls in adults aged 65 and older in the United States.

Design

Trends in coding and reporting practices of fatal falls were evaluated under mortality coding schemes for International Classification of Diseases (ICD), Ninth Revision (1992–1998) and Tenth Revision (1999–2005).

Setting

United States, 1992 to 2005.

Participants

Individuals aged 65 and older with falls listed as the underlying cause of death (UCD) on their death certificates.

Measurements

The primary outcome was annual fatal falls rates per 100,000 U.S. residents aged 65 and older. Coding practice was assessed through analysis of trends in rates of specific UCD fall ICD e‐codes over time. Reporting quality was assessed by examining changes in the location on the death certificate where fall e‐codes were reported, in particular, the percentage of fall e‐codes recorded in the proper location on the death certificate.

Results

Fatal falls rates increased over both time periods: 1992 to 1998 and 1999 to 2005. A single falls e‐code was responsible for the increasing trend of fatal falls overall from 1992 to 1998 (E888, other and unspecified fall) and from 1999 to 2005 (W18, other falls on the same level), whereas trends for other falls e‐codes remained stable. Reporting quality improved steadily throughout the study period.

Conclusion

Better reporting quality, not coding practices, contributed to the increasing rate of fatal falls in older adults in the United States from 1992 to 2005.
Public Disclosure to Improve Physical Education in an Urban School District: Results From a 2‐Year Quasi‐Experimental Study
Authors: Thompson Hannah R. , Vittinghoff Eric , Linchey Jennifer K. , Madsen Kristine A.
Published: July 2015

BACKGROUND

Many elementary schools have policies requiring a minimum amount of physical education (PE). However, few schools comply with local/state PE policy and little is known about how to improve adherence. We evaluated changes in PE among fifth‐grade classes, following participatory action research efforts to improve PE quantity and policy compliance that focused on publically disclosing PE data.

METHODS

Data were collected in 20 San Francisco public elementary schools in spring 2011 and 2013. PE schedules were collected and PE classes were directly observed (2011, N = 30 teachers; 2013, N = 33 teachers). Data on the proportion of schools meeting state PE mandates in 2011 were shared within the school district and disclosed to the general public in 2012.

RESULTS

From 2011 to 2013, PE increased by 11 minutes/week based on teachers' schedules (95% CI: 3.0, 19.6) and by 14 minutes/week (95% CI: 1.9, 26.0) based on observations. The proportion of schools meeting the state PE mandate increased from 20% to 30% (p = .27).

CONCLUSIONS

Positive changes in PE were seen over a 2‐year period following the public disclosure of data that highlighted poor PE policy compliance. Public disclosure could be a method for ensuring greater PE policy adherence.
Trends in Cyberbullying and School Bullying Victimization in a Regional Census of High School Students, 2006‐2012
Authors: Kessel Schneider Shari , O'Donnell Lydia , Smith Erin
Published: July 2015

BACKGROUND

Schools are increasingly being called upon to address cyberbullying and its consequences. This study compares cyberbullying and school bullying trends and examines help‐seeking among cyberbullying victims.

METHODS

We analyzed self‐report data over 4 surveys (2006‐2012) from more than 16,000 students in 17 MetroWest Boston high schools. Using generalized estimating equations, we examined school and cyberbullying victimization trends by sex, grade, and sexual orientation.

RESULTS

From 2006 to 2012, cyberbullying increased from 15% to 21% (p < .001). In 2006, school bullying was 1.7 times higher than cyberbullying (26% versus 15%); by 2012, school bullying and cyberbullying were similar (23% versus 21%). Cyberbullying increased more among girls (17% to 27%; p < .001) than boys (12% to 15%; p < .001). There was no net increase in school bullying among girls (26% in 2006 and 2012) and a decrease among boys (25% to 18%; p < .001). Sexual minorities were more likely than heterosexuals to be bullied at school and online at every survey. Only 33% of cyberbullying victims told an adult; more victims told parents/non‐school adults (29%) than school adults (17%).

CONCLUSIONS

Despite decreases in school bullying, cyberbullying rose steadily, particularly among girls. Increased attention to sociodemographic differences in bullying could promote help‐seeking and positive online behavior.
How Food as a Reward Is Detrimental to Children's Health, Learning, and Behavior
Authors: Fedewa Alicia L. , Davis Matthew Cody
Published: July 2015

BACKGROUND

Despite small‐ and wide‐scale prevention efforts to curb obesity, the percentage of children classified as overweight and obese has remained relatively consistent in the last decade. As school personnel are increasingly pressured to enhance student performance, many educators use food as a reward to motivate and reinforce positive behavior and high achievement. Yet, many educators have missed the link between student health and academic achievement.

METHODS

Based on a review of the literature, this article explores the link between childhood obesity and adverse mental and physical health, learning, and behavior outcomes. The role in providing children with food as a reward in the relationship between obesity and detrimental health and performance outcomes are examined.

RESULTS

The use of food as a reward is pervasive in school classrooms. Although there is a paucity of research in this area, the few studies published in this area show detrimental outcomes for children in the areas of physical health, learning, and behavior.

CONCLUSIONS

It is imperative that educators understand the adverse outcomes associated with using food as a reward for good behavior and achievement. This study provides alternatives to using food as a reward and outlines future directions for research.
‘Rachel's not here’: Constructed dialogue in gossip
Authors: Mohammad Abeer , Vásquez Camilla
Published: July 2015

Sociolinguistic research has demonstrated that gossip is a co‐constructed phenomenon, which allows participants to establish solidarity and build alignments with each other, while evaluating an absent party. Gossip can also serve important social functions, such as helping to establish and reconfirm group norms and values. The present study provides a detailed analysis of an extended gossip episode that occurred within an institutional context: a study group interaction at a U.S. university. Our analysis shows how, in gossip, constructed dialogue both prompts and legitimizes pejorative evaluations towards an absent third party, and is actually the pivot around which group members negotiate values and norms in the process of arriving at a shared moral stance. Our analysis also demonstrates that alignment in gossip interactions is tenuous and must be continuously renewed.
Convenience Sampling for Acceptability and CATA Measurements May Provide Inaccurate Results: A Case Study with Fruit‐Flavored Powdered beverages Tested in Argentina, Spain and U.S.A.
Authors: Cardinal Paula , Zamora Maria Clara , Chambers Edgar , Carbonell Barrachina Ángel , Hough Guillermo
Published: July 2015

The objective of this study was to measure the sensory acceptability and obtain check‐all‐that‐apply (CATA) responses for fruit‐flavored powdered juices, with three different consumer segments: children and women who could be considered target populations, and a convenience sample of food‐science‐related consumers (FSRC). The study was conducted with a total of 550 consumers in four cities: Alicante (Spain), Buenos Aires (Argentina), Manhattan (U.S.A.) and 9 de Julio (Argentina). The products were reconstituted powdered juices with the following flavors: apple, cherry, grape, grapefruit, orange and pear. Overall, FSRC consumers had the lowest acceptability scores for these products. Regarding CATA results, multiple correspondence analysis showed cherry and grape juices were associated to artificial‐flavor and artificial‐color, with the FSRC respondents being mainly responsible for the use of these descriptors. Pear and orange were considered to have natural‐flavor and good‐color, mainly by children and women. A generalized linear model was used to analyze the effect of “sample,” “city” and “consumer segment” on the percentage of checks given to each descriptor. The “consumer segment” effect was significant for nearly all descriptors, with FSRC checking samples differently to women and children.

Practical Applications

When convenience samples are assembled for food acceptability or CATA studies, the most convenient consumers to recruit often are food science students, staff or, in the case of companies, food science professionals or technicians. The consequences of using these convenience samples are not always considered. The present research is conclusive in showing the significant differences between FSRC and target populations, both in measuring acceptability and in consumer description using the CATA methodology. Development projects based on acceptability results from convenience samples of food scientists, students or technicians could lead to erroneous development directions.
Melatonin and endoplasmic reticulum stress: relation to autophagy and apoptosis
Authors: Fernández Anna , Ordóñez Raquel , Reiter Russel J. , González‐Gallego Javier , Mauriz José L.
Published: July 2015

Endoplasmic reticulum (ER) is a dynamic organelle that participates in a number of cellular functions by controlling lipid metabolism, calcium stores, and proteostasis. Under stressful situations, the ER environment is compromised, and protein maturation is impaired; this causes misfolded proteins to accumulate and a characteristic stress response named unfolded protein response (UPR). UPR protects cells from stress and contributes to cellular homeostasis re‐establishment; however, during prolonged ER stress, UPR activation promotes cell death. ER stressors can modulate autophagy which in turn, depending of the situation, induces cell survival or death. Interactions of different autophagy‐ and apoptosis‐related proteins and also common signaling pathways have been found, suggesting an interplay between these cellular processes, although their dynamic features are still unknown. A number of pathologies including metabolic, neurodegenerative and cardiovascular diseases, cancer, inflammation, and viral infections are associated with ER stress, leading to a growing interest in targeting components of the UPR as a therapeutic strategy. Melatonin has a variety of antioxidant, anti‐inflammatory, and antitumor effects. As such, it modulates apoptosis and autophagy in cancer cells, neurodegeneration and the development of liver diseases as well as other pathologies. Here, we review the effects of melatonin on the main ER stress mechanisms, focusing on its ability to regulate the autophagic and apoptotic processes. As the number of studies that have analyzed ER stress modulation by this indole remains limited, further research is necessary for a better understanding of the crosstalk between ER stress, autophagy, and apoptosis and to clearly delineate the mechanisms by which melatonin modulates these responses.
Polyamines in macroalgae: advances and future perspectives
Authors: Schweikert Katja , Burritt David J.
Published: July 2015

Polyamines (PA) are ubiquitous, small, aliphatic cations found in all living cells. In recent years the importance of these molecules for macroalgae has become evident and a substantial body of knowledge has been accumulated over the last three decades. This review summarizes research on the PAs found in macroalgae, their transport and metabolism, and their biological significance in processes such as cell division, chloroplast development, and reproduction. The involvement of PAs in environmental stress responses in macroalgae is also addressed. The discussion of PAs in this review not only demonstrates that PAs play an important role in physiological processes in macroalgae, but also clearly demonstrates the similarities and differences between PA metabolism in macroalgae and higher plants. Key areas for future research are also discussed.
Sex dimorphism in periodontitis in animal models
Authors: Duan X. , Gleason R. C. , Li F. , Hosur K. B. , Duan X. , Huang D. , Wang H. , Hajishengallis G. , Liang S.
Published: July 2015

Background and Objective

Although surveys in the USA have shown that male subjects are more prone to develop periodontitis, sex as a risk factor in periodontitis, and its mechanism, remain controversial. Animal models are ideal for investigating immunological mechanisms of sex dimorphism in periodontitis because in these models it is possible to exclude the interference of gender‐related risk factors, such as smoking and oral hygiene habits. Based on surveys in humans and reports on sex dimorphism in other diseases, our hypothesis is that sex is a risk factor in periodontitis.

Material and Methods

Different murine models (oral gavage model and ligature model) for periodontitis have been utilized to determine susceptibility to periodontitis in female and male mice. Periodontal bone levels were measured as the distance from the cemento–enamel junction to the alveolar bone crest (CEJ‐ABC) in young female or male mice (8–10 wk of age). Differential expression of inflammatory mediators in the gingivae of female and male mice was determined by quantitative real‐time PCR.

Results

In comparison with male mice, female mice displayed significantly (p < 0.05) increased periodontal bone loss, accompanied by elevated expression of proinflammatory cytokines (interleukin‐1β, interleukin‐6 and interleukin‐17A) and higher numbers of oral bacteria.

Conclusion

In contrast to the results in humans, in which periodontitis susceptibility is also influenced by confounding gender‐related behaviors, in the murine oral gavage model and ligature model, female mice appear to be more susceptible to periodontal bone loss than male mice. In the ligature model, we observed significantly (p < 0.05) higher CEJ‐ABC distance, gingival proinflammatory cytokine production and number of oral bacteria in female mice. Furthermore, our results imply that female mice develop periodontitis with a higher progression rate. Our study has therefore established that animal models can be used to dissect the mechanisms underlying genuine gender‐based differences in periodontal disease susceptibility and/or progression.
Effect of Voided Volume on Voiding Patterns and Reliability of Uroflowmetry‐Electromyography Results in Children with Lower Urinary Tract Dysfunction
Authors: DAYANC M. Murat , KIBAR Yusuf , IRKILATA H. Cem , SANCAKTUTAR Ahmet A. , EBILOGLU Turgay , GUR Ahmet , ERGIN Giray , ALP Bilal F. , GOK Faysal
Published: July 2015

Objective

To examine whether voided volume (VV) could change the uroflow patterns and result in children with lower urinary tract dysfunction (LUTD).

Methods

Between January 2009 and May 2010, the children with LUTD were enrolled in this study. Uroflowmetry (UF) combined with electromyography (EMG) was performed two times and was reviewed independently by two urologists. UF‐EMG curves were classified as bell, staccato, intermittent, plateau, and tower. Patients' expected bladder capacity (EBC) and VV were recorded. Patients were divided into four groups according to their VV and EBC. Group 1, VV <50% of EBC; group 2, VV between 50 and 100% of EBC; group 3, VV between 100 and 125% of EBC; group 4, VV >125% of EBC.

Results

A total of 143 patients underwent UF‐EMG at least two times and 382 results were obtained. Groups 1, 2, 3 and 4 consisted of 27, 60, 27 and 29 children, respectively. The percentages of normal, intermittent, plateau voiding patterns were 58.5, 12.8, 7.1% in group 1; 79.8, 5.4, 1.8% in group 2; 59.2, 8.5, 2.8% in group 3; and 37.2, 5.1, 2.6% in group 4, respectively. The percentages of staccato and tower pattern were 1.4, 20% in group 1; 9.1, 3.6% in group 2; 30, 0% in group 3; and 55.1, 0% in group 4, respectively. The rate of tower shape curve decreased as voided volume increased, but the rate of staccato curve increased as voided volume increased.

Conclusions

In case of exceeding the EBC, the test should be repeated with normal VV when UF results are being evaluated.
Survival of refractory presolar grain analogs during Stardust‐like impact into Al foils: Implications for Wild 2 presolar grain abundances and study of the cometary fine fraction
Authors: Croat T. K. , Floss C. , Haas B. A. , Burchell M. J. , Kearsley A. T.
Published: July 2015

We present results of FIB–TEM studies of 12 Stardust analog Al foil craters which were created by firing refractory Si and Ti carbide and nitride grains into Al foils at 6.05 km s−1 with a light‐gas gun to simulate capture of cometary grains by the Stardust mission. These foils were prepared primarily to understand the low presolar grain abundances (both SiC and silicates) measured by SIMS in Stardust Al foil samples. Our results demonstrate the intact survival of submicron SiC, TiC, TiN, and less‐refractory Si3N4 grains. In small (<2 μm) craters that are formed by single grain impacts, the entire impacting crystalline grain is often preserved intact with minimal modification. While they also survive in crystalline form, grains at the bottom of larger craters (>5 μm) are typically fragmented and are somewhat flattened in the direction of impact due to partial melting and/or plastic deformation. The low presolar grain abundance estimates derived from SIMS measurements of large craters (mostly >50 μm) likely result from greater modification of these impactors (i.e., melting and isotopic dilution), due to higher peak temperatures/pressures in these crater impacts. The better survivability of grains in smaller craters suggests that more accurate presolar grain estimates may be achievable through measurement of such craters. It also suggests small craters can provide a complementary method of study of the Wild 2 fine fraction, especially for refractory CAI‐like minerals.
Experiences regarding maternal age‐specific risks and prenatal testing of women of advanced maternal age in Japan
Authors: Murakami Kyoko , Turale Sue , Skirton Heather , Doris Faye , Tsujino Kumiko , Ito Misae , Kutsunugi Saeko
Published: July 2015

The number of pregnant women of advanced maternal age has increased worldwide. Women in this group have an increased chance of fetal abnormality. To explore Japanese women's experiences regarding maternal age‐specific risks and prenatal testing, we conducted a descriptive qualitative study. Semi‐structured interviews were conducted with 16 women aged 35 years or over who had given birth within the previous three months to a healthy, term infant. Thematic analysis of transcribed interview data was performed and three major themes were identified: inadequate understanding of genetic risks; insufficiently informed choice regarding prenatal testing; and need for more information from health professionals. Some participants were not aware of maternal age‐specific risks to the fetus. Many took their cues from health professionals and did not raise the topic themselves, but would have considered prenatal testing if made aware of the risks. Nurses, midwives and other health professionals need to adequately inform pregnant women about the genetic risks to the fetus and offer testing at an appropriate stage early in the pregnancy.
How does biomass distribution change with size and differ among species? An analysis for 1200 plant species from five continents
Authors: Poorter Hendrik , Jagodzinski Andrzej M. , Ruiz‐Peinado Ricardo , Kuyah Shem , Luo Yunjian , Oleksyn Jacek , Usoltsev Vladimir A. , Buckley Thomas N. , Reich Peter B. , Sack Lawren
Published: July 2015

We compiled a global database for leaf, stem and root biomass representing c. 11 000 records for c. 1200 herbaceous and woody species grown under either controlled or field conditions. We used this data set to analyse allometric relationships and fractional biomass distribution to leaves, stems and roots.

We tested whether allometric scaling exponents are generally constant across plant sizes as predicted by metabolic scaling theory, or whether instead they change dynamically with plant size. We also quantified interspecific variation in biomass distribution among plant families and functional groups.

Across all species combined, leaf vs stem and leaf vs root scaling exponents decreased from c. 1.00 for small plants to c. 0.60 for the largest trees considered. Evergreens had substantially higher leaf mass fractions (LMFs) than deciduous species, whereas graminoids maintained higher root mass fractions (RMFs) than eudicotyledonous herbs.

These patterns do not support the hypothesis of fixed allometric exponents. Rather, continuous shifts in allometric exponents with plant size during ontogeny and evolution are the norm. Across seed plants, variation in biomass distribution among species is related more to function than phylogeny. We propose that the higher LMF of evergreens at least partly compensates for their relatively low leaf area : leaf mass ratio.
Therapeutic potential of resveratrol in heart failure
Authors: Sung Miranda M. , Dyck Jason R.B.
Published: July 2015

Despite existing therapies, patients with heart failure have a very poor quality of life and a high 1‐year mortality rate. Given the impact of this syndrome on health outcomes, research is being directed toward identifying novel strategies to treat heart failure symptoms as well as to prolong survival. One molecule that has been tested in animal models for this purpose is resveratrol. Resveratrol is a naturally occurring polyphenol found in several plants, and administration of resveratrol has been shown to prevent and/or slow the progression of heart failure in animal models of heart failure induced by myocardial infarction, pressure overload, myocarditis, and chemotherapy‐induced cardiotoxicity. In addition, some animal studies have shown that resveratrol improves cardiac function and survival when administered as a treatment for established heart failure. Furthermore, as heart failure induces alterations in skeletal muscle and vasculature that also contribute to certain heart failure symptoms, such as fatigue and exercise intolerance, it has also been shown that resveratrol acts on these peripheral tissues to improve skeletal muscle and endothelial/vascular function. Therefore, if these animal studies translate to humans, resveratrol may prove to be a novel therapy for the treatment of heart failure.
Aggregatibacter actinomycetemcomitans, a potent immunoregulator of the periodontal host defense system and alveolar bone homeostasis
Authors: Herbert B.A. , Novince C.M. , Kirkwood K.L.
Published: July 2015

Aggregatibacter actinomycetemcomitans is a perio‐pathogenic bacteria that has long been associated with localized aggressive periodontitis. The mechanisms of its pathogenicity have been studied in humans and preclinical experimental models. Although different serotypes of A. actinomycetemcomitans have differential virulence factor expression, A. actinomycetemcomitans cytolethal distending toxin (CDT), leukotoxin, and lipopolysaccharide (LPS) have been most extensively studied in the context of modulating the host immune response. Following colonization and attachment in the oral cavity, A. actinomycetemcomitans employs CDT, leukotoxin, and LPS to evade host innate defense mechanisms and drive a pathophysiologic inflammatory response. This supra‐physiologic immune response state perturbs normal periodontal tissue remodeling/turnover and ultimately has catabolic effects on periodontal tissue homeostasis. In this review, we have divided the host response into two systems: non‐hematopoietic and hematopoietic. Non‐hematopoietic barriers include epithelium and fibroblasts that initiate the innate immune host response. The hematopoietic system contains lymphoid and myeloid‐derived cell lineages that are responsible for expanding the immune response and driving the pathophysiologic inflammatory state in the local periodontal microenvironment. Effector systems and signaling transduction pathways activated and utilized in response to A. actinomycetemcomitans will be discussed to further delineate immune cell mechanisms during A. actinomycetemcomitans infection. Finally, we will discuss the osteo‐immunomodulatory effects induced by A. actinomycetemcomitans and dissect the catabolic disruption of balanced osteoclast–osteoblast‐mediated bone remodeling, which subsequently leads to net alveolar bone loss.
Screening for resistance to black rot in a Spanish collection of Brassica rapa
Authors: Lema Margarita , Cartea María Elena , Francisco Marta , Velasco Pablo , Soengas Pilar
Published: July 2015

Productivity and quality of crops of Brassica rapa L. in north‐western of Spain are highly affected by black rot, caused by the bacterium Xanthomonas campestris pv. campestris (Pammel) Dowson (Xcc). Several races of Xcc have been described in this area, being the race 6 the most frequent in B. rapa crops and races 1 and 4 the most frequent in B. oleracea crops. The control of the disease can be aided by the employment of resistant varieties. The aim of this work was to find sources of resistance to Xcc in a collection of open‐pollinated varieties of B. rapa from north‐western Spain. Resistance was evaluated in 191 landraces. Partial resistance to races 6, 1 and 4 and complete resistance to race 4 were identified in several landraces. Several accessions exhibited partial resistance to the three races. Sources of resistance were identified in landraces of different crops of the species (turnips, turnip greens and turnip tops). These landraces could be grown after selection for resistance or they can be donors of resistance genes in breeding programmes.
Racial/Ethnic Differences in Gestational Diabetes Prevalence and Contribution of Common Risk Factors
Authors: Pu Jia , Zhao Beinan , Wang Elsie J. , Nimbal Vani , Osmundson Sarah , Kunz Liza , Popat Rita A. , Chung Sukyung , Palaniappan Latha P.
Published: July 2015

Background

The White House, the American Heart Association, the Agency for Healthcare Research and Quality, and the National Heart, Lung and Blood Institute have all recently acknowledged the need to disaggregate Asian American subgroups to better understand this heterogeneous racial group. This study aims to assess racial/ethnic differences in relative contribution of risk factors of gestational diabetes mellitus (GDM) among Asian subgroups (Asian Indian, Chinese, Filipino, Japanese, Korean, and Vietnamese), Hispanics, non‐Hispanic blacks, and non‐Hispanic whites.

Methods

Pregnant women in 2007–2012 were identified through California state birth certificate records and linked to the electronic health records in a large mixed‐payer ambulatory care organisation in Northern California (n = 24 195). Relative risk and population attributable fraction (PAF) for specific racial/ethnic groups were calculated to assess the contributions of advanced maternal age, overweight/obesity (Centers for Disease Control and Prevention (CDC) standards and World Health Organization (WHO)/American Diabetes Association (ADA) body mass index cut‐offs for Asians), family history of type 2 diabetes, and foreign‐born status.

Results

GDM was most prevalent among Asian Indians (19.3%). Relative risks were similar across all race/ethnic groups. Advanced maternal age had higher PAFs in non‐Hispanic whites (22.5%) and Hispanics (22.7%). Meanwhile family history (Asian Indians 22.6%, Chinese 22.9%) and foreign‐borne status (Chinese 40.2%, Filipinos 30.2%) had higher PAFs in Asian subgroups. Overweight/obesity was the most important GDM risk factor for non‐Hispanic whites, Hispanics, Asian Indians, and Filipinos when the WHO/ADA cut‐off points were applied. Advanced maternal age was the only risk factor studied that was modified by race/ethnicity, with non‐Hispanic white and Hispanic women being more adversely affected than other racial/ethnic groups.

Conclusions

Overweight/obesity, advanced maternal age, family history of type 2 diabetes, and foreign‐borne status are important risk factors for GDM. The relative contributions of these risk factors differ by race/ethnicity, mainly due to differences in population prevalence of these risk factors.
Creating Tactile Space during a University Extension Field Day Event: The Case of a Sustainable Agriculture Innovation
Authors: Cowan Jeremy S. , Goldberger Jessica R. , Miles Carol A. , Inglis Debra A.
Published: July 2015

Drawing on the concept of “tactile space,” we evaluate the experiential learning environment of a university extension field day event focused on a sustainable agriculture innovation: biodegradable plastic mulch. Introduced by sociologist Michael Carolan, “tactile spaces” are sensuously rich learning environments where participants interact with each other and the environment in an “embodied” and “embedded” manner leading to long‐lasting attitudinal and behavioral change. In our study, farmers, extension professionals, crop consultants, and mulch manufacturers participated in a field day event designed to provide both embodied and embedded experiences in an effort to stimulate interest in biodegradable plastic mulch, an economically and environmentally sustainable alternative to polyethylene mulch. Field day participants engaged in hands‐on demonstrations preceded and followed by focus group sessions. Enhancing the learning environment in these ways improved the success of the field day event by encouraging practice‐based forms of learning, which supplemented and reinforced the claims made about biodegradable plastic mulch. However, the tactile space could have been enriched by providing more opportunities for participants to become embedded within the environment, and by adding elements to overcome the temporal limitations of the field day event. This research contributes to the broader literature on participatory research and extension.
Stock Returns and Exchange Rate Nexus in Ghana: A Bayesian Quantile Regression Approach
Authors: Boako Gideon , Omane‐Adjepong Maurice , Frimpong Joseph Magnus
Published: July 2015

This paper presents analysis of the relationship and dependence structure between stock returns and exchange rates in Ghana using data of daily periodicity from January 4, 2011 to July 31, 2014. Analyses are conducted by means of Bayesian quantile regression (QR) technique and multiple causality tests. Our findings suggest high dependence of the equity market on the foreign exchange market in Ghana, and that the link between the two markets follows the international trade‐oriented model more than the portfolio balance theory. We report that among the six exchange rates used, only the cedi–dollar registers instantaneous effect on the equity market.
The Economic Value of Time: Evidence from Africa
Authors: Wondemu Kifle
Published: July 2015

When excessive and inefficiently implemented, government interventions can result in significant economic losses for citizens. These include the often‐significant cost of lost time. This paper thus aims to estimate the potential economic welfare benefit of reducing public office waiting times. Based on data from Johannesburg, Lagos and Addis Ababa, we show that a one‐hour reduction in waiting time improves welfare by 66‐74% of the average local wage. High‐income earners, college graduates and private‐sector employees enjoy higher gains. Moreover, we note that the proxies currently used to quantify time‐saving benefits diverge significantly from the rate at which individuals substitute time for money. Our analysis also indicated a substantial delay‐induced citywide efficiency loss. Introducing public–private partnership and charging premium fees for faster service delivery are justifiable both on grounds of equity and efficiency.
Trajectories of Breadth of Participation in Organized Activity During Childhood
Authors: Aumètre Florence , Poulin François
Published: July 2015

This study aimed to identify the trajectories of breadth of participation in organized activities during childhood and to examine the predictors of membership in these trajectories (child's individual and family characteristics measured in Kindergarten). A sample of 1038 children, recruited in Kindergarten, was assessed yearly between Kindergarten and grade 4. Semiparametric group‐based modeling brought out four trajectories: the no participation group (13.5 percent), the increasing group (26.4 percent), the decreasing group (14.1 percent), and the high group (46.1 percent). Prosociality predicted membership in the no participation group, as compared with the increasing group. Social withdrawal predicted membership in the no participation group, as compared with the high group. High family income and higher maternal education predicted membership in the increasing, decreasing, and high trajectory groups, as compared with the no participation group. Higher paternal education predicted membership in the high group, as compared with the increasing group. Overall, family variables had a greater impact than individual variables on the probability that the child would participate in a broader range of organized activities.
Chinese Trust in the Police: The Impact of Political Efficacy and Participation
Authors: Hu Rong , Sun Ivan Y. , Wu Yuning
Published: July 2015

Objective

We assessed the influences of political efficacy and political participation on public perceptions of police trustworthiness in China.

Methods

Drawing upon approximately 10,000 cases collected by the Chinese General Social Survey (CGSS), we used multivariate regression to assess the impact of two types of political efficacy, internal efficacy and external efficacy, and three forms of political participation, engaging in community affairs, grassroots election, and rightful resistance, on public trust in the police, controlling for demographics and social trust and justice.

Results

We found that external efficacy and grassroots election are positively related to trust in the police, whereas internal efficacy and rightful resistance are negatively associated with such trust. Background characteristics, such as gender, ethnicity, age, education, and household registration, and social trust and justice variables are also predictive of Chinese perceptions of police trustworthiness.

Conclusion

Political efficacy and participation mattered in influencing trust in the police. The Chinese government should continue its political reforms by allowing greater public participation in the selection of political representatives and the decision‐making process of public policy.
Bronchiolitis obliterans syndrome due to donor‐specific HLA‐antibodies
Authors: Kauke T. , Kneidinger N. , Martin B. , Dick A. , Schneider C. , Schramm R. , Meimarakis G. , Preissler G. , Eickelberg O. , von Dossow V. , Behr J. , Hatz R. , Neurohr C. , Winter H.
Published: July 2015

Chronic lung allograft dysfunction (CLAD) is a limiting factor for long‐term survival in lung transplant recipients. Donor‐specific human leukocyte antigen (HLA)‐antibodies (DSA) have been suggested as potential risk factors for CLAD. However, their impact on clinical outcome following lung transplantation remains controversial. We performed a single‐center study of 120 lung transplant recipients transplanted between 2006 and 2011. Patient sera were investigated before and after transplantation. The sera were screened by means of Luminex® technology (Luminex Inc., Austin, TX, USA) for IgG‐HLA‐class I and class II antibodies (ab). Using single antigen beads, DSA were identified and correlated retrospectively with clinical parameters. After transplantation 39 out of 120 patients (32.5%) were positive for HLA‐ab. The incidence of de novo DSA formation was 27 of 120 patients (22.5%). Eleven of 27 (41%) of de novo DSA‐positive patients developed BOS compared to 13 of 93 (14%) DSA‐negative patients (p = 0.002). Furthermore, the generation of de novo DSA was independently associated with the development of BOS in multivariable analysis [hazard ration (HR) 2.5, 95% confidence interval (CI) 1.0–6.08; p = 0.046). Our results indicate that de novo DSA are associated with the development of BOS after lung transplantation. Monitoring of HLA‐ab after transplantation is useful for identifying high‐risk patients and offers an opportunity for early therapeutic intervention.
A novel HLA‐DQ allele, HLA‐DQB1*05:48, found in the Saudi Stem Cells Donor Registry
Authors: Fakhoury H. A. , Alaskar A. S. , Hajeer A. H.
Published: July 2015

The allele HLA‐DQB1*05:48 differs from HLA‐DQB1*05:01:01 by a non‐synonymous T to C substitution at nucleotide position 1693 in exon 2.
Predicting storage‐dependent damage to red blood cells using nitrite oxidation kinetics, peroxiredoxin‐2 oxidation, and hemoglobin and free heme measurements
Authors: Oh Joo‐Yeun , Stapley Ryan , Harper Victoria , Marques Marisa B. , Patel Rakesh P.
Published: July 2015

BACKGROUND

Storage‐dependent damage to red blood cells (RBCs) varies significantly. Identifying RBC units that will undergo higher levels of hemolysis during storage may allow for more efficient inventory management decision‐making. Oxidative‐stress mediates storage‐dependent damage to RBCs and will depend on the oxidant:antioxidant balance. We reasoned that this balance or redox tone will serve as a determinant of how a given RBC unit stores and that its assessment in “young” RBCs will predict storage‐dependent hemolysis.

STUDY DESIGN AND METHODS

RBCs were sampled from bags and segments stored for 7 to 42 days. Redox tone was assessed by nitrite oxidation kinetics and peroxiredoxin‐2 (Prx‐2) oxidation. In parallel, hemolysis was assessed by measuring cell‐free hemoglobin (Hb) and free heme (hemin). Correlation analyses were performed to determine if Day 7 measurements predicted either the level of hemolysis at Day 35 or the increase in hemolysis during storage.

RESULTS

Higher Day 7 Prx‐2 oxidation was associated with higher Day 35 Prx‐2 oxidation, suggesting that early assessment of this variable may identify RBCs that will incur the most oxidative damage during storage. RBCs that oxidized nitrite faster on Day 7 were associated with the greatest levels of storage‐dependent hemolysis and increases in Prx‐2 oxidation. An inverse relationship between storage‐dependent changes in oxyhemoglobin and free heme was observed underscoring an unappreciated reciprocity between these molecular species. Moreover, free heme was higher in the bag compared to paired segments, with opposite trends observed for free Hb.

CONCLUSION

Measurement of Prx‐2 oxidation and nitrite oxidation kinetics early during RBC storage may predict storage‐dependent damage to RBC including hemolysis‐dependent formation of free Hb and heme.
Modeling Gravity and Turbidity Currents: Computational Approaches and Challenges
Authors: Meiburg Eckart , Radhakrishnan Senthil , Nasr-Azadani Mohamad
Published: July 2015

In this review article, we discuss recent progress with regard to modeling gravity-driven, high Reynolds number currents, with the emphasis on depth-resolving, high-resolution simulations. The initial sections describe new developments in the conceptual modeling of such currents for the purpose of identifying the Froude number–current height relationship, in the spirit of the pioneering work by von Kármán and Benjamin. A brief introduction to depth-averaged approaches follows, including box models and shallow water equations. Subsequently, we provide a detailed review of depth-resolving modeling strategies, including direct numerical simulations (DNS), large-eddy simulations (LES), and Reynolds-averaged Navier–Stokes (RANS) simulations. The strengths and challenges associated with these respective approaches are discussed by highlighting representative computational results obtained in recent years.
Experimental Measurement of Direct Thermal Radiation Through Single-Layer Square-Cell Plain Woven Screens
Authors: Hashempour Javad , Sharifian Ahmad , Billingsley John
Published: July 2015

Australian bushfires have repeatedly killed many people and caused severe damage. Previous studies have identified direct flame contact and radiant heat as the main cause of fatalities. The role of screens to limit the radiation exposure of an object by a fire on the opposite side of the screen is well-known, but still it has not been experimentally quantified. A screen between a radiation source and an object divides the radiant heat flux (RHF) into two parts. The first part is the direct RHF (DRHF) that passes directly through the screen without any interaction. The second part is indirect RHF (IRHF), which includes both emitted and reflected RHFs by the heated screen. This experimental study deals with the DRHF, which is dependent on the screen porosity and is independent of the material composition or the surface quality of the screen. The experimental results of four square-cell, plain woven screens, with porosities ranging from 41% to 66%, show that the passing ratios (PRs) of DRHF through screens are less than those suggested by their porosity. Four empirical equations have been developed to determine the PR of the direct radiation through screen and the tunnel vision angles of the screens.
Prior Distributions of Material Parameters for Bayesian Calibration of Growth and Remodeling Computational Model of Abdominal Aortic Wall
Authors: Seyedsalehi Sajjad , Zhang Liangliang , Choi Jongeun , Baek Seungik
Published: July 2015

For the accurate prediction of the vascular disease progression, there is a crucial need for developing a systematic tool aimed toward patient-specific modeling. Considering the interpatient variations, a prior distribution of model parameters has a strong influence on computational results for arterial mechanics. One crucial step toward patient-specific computational modeling is to identify parameters of prior distributions that reflect existing knowledge. In this paper, we present a new systematic method to estimate the prior distribution for the parameters of a constrained mixture model using previous biaxial tests of healthy abdominal aortas (AAs). We investigate the correlation between the estimated parameters for each constituent and the patient's age and gender; however, the results indicate that the parameters are correlated with age only. The parameters are classified into two groups: Group-I in which the parameters ce, ck1, ck2, cm2,Ghc, and ϕe are correlated with age, and Group-II in which the parameters cm1, Ghm, G1e, G2e, and α are not correlated with age. For the parameters in Group-I, we used regression associated with age via linear or inverse relations, in which their prior distributions provide conditional distributions with confidence intervals. For Group-II, the parameter estimated values were subjected to multiple transformations and chosen if the transformed data had a better fit to the normal distribution than the original. This information improves the prior distribution of a subject-specific model by specifying parameters that are correlated with age and their transformed distributions. Therefore, this study is a necessary first step in our group's approach toward a Bayesian calibration of an aortic model. The results from this study will be used as the prior information necessary for the initialization of Bayesian calibration of a computational model for future applications.
Graphene Oxide Colloidal Suspensions as Cutting Fluids for Micromachining—Part I: Fabrication and Performance Evaluation
Authors: Chu Bryan , Singh Eklavya , Samuel Johnson , Koratkar Nikhil
Published: July 2015

This paper is aimed at investigating the effects of graphene oxide platelet (GOP) geometry (i.e., lateral size and thickness) and oxygen functionalization on the cooling and lubrication performance of GOP colloidal suspensions. The techniques of thermal reduction and ultrasonic exfoliation were used to manufacture three different types of GOPs. For each of these three types of GOPs, colloidal solutions with GOP concentrations varying between 0.1 and 1 wt.% were evaluated for their dynamic viscosity, thermal conductivity, and micromachining performance. The ultrasonically exfoliated GOPs (with 2–3 graphene layers and lowest in-solution characteristic lateral length of 120 nm) appear to be the most favorable for micromachining applications. Even at the lowest concentration of 0.1 wt.%, they are capable of providing a 51% reduction in the cutting temperature and a 25% reduction in the surface roughness value over that of the baseline semisynthetic cutting fluid. For the thermally reduced GOPs (TR GOPs) (with 4–8 graphene layers and in-solution characteristic lateral length of 562–2780 nm), a concentration of 0.2 wt.% appears to be optimal. The findings suggest that the differences seen between the colloidal suspensions in terms of their droplet spreading, evaporation, and the subsequent GOP film-formation characteristics may be better indicators of their machining performance, as opposed to their bulk fluid properties.
A New Singularity Treatment Approach for Journal-Bearing Mixed Lubrication Modeled by the Finite Difference Method With a Herringbone Mesh
Authors: Han Yanfeng , Xiong Shangwu , Wang Jiaxu , Jane Wang Q.
Published: July 2015

Steady-state mixed hydrodynamic lubrication of rigid journal bearing is investigated by using a finite difference form of the Patir–Cheng average Reynolds equation under the Reynolds boundary condition. Two sets of discretization meshes, i.e., the rectangular and nonorthogonal herringbone meshes, are considered. A virtual-mesh approach is suggested to resolve the problem due to the singularities of pressure derivatives at the turning point of the herringbone mesh. The effectiveness of the new approach is examined by comparing the predicted load with that found in the literature for a smooth-surface case solved in the conventional rectangular mesh. The effects of the skewness angles of symmetric and asymmetric herringbone meshes on the predicted parameters, such as load, friction coefficient, attitude angle, and maximum pressure, are investigated for smooth, rough, and herringbone-grooved bearing surfaces. It is found that the new approach helps to improve the computational accuracy significantly, as demonstrated by comparing the results with and without the treatment of the pressure derivative discontinuity although the latter costs slightly less computational time.
Effect of Low-Frequency Modulation on Deformation and Material Flow in Cutting of Metals
Authors: Yeung Ho , Guo Yang , Mann James B. , Dale Compton W. , Chandrasekar Srinivasan
Published: July 2015

The deformation field, material flow, and mechanics of chip separation in cutting of metals with superimposed low-frequency modulation (<1000 Hz) are characterized at the mesoscale using high-speed imaging and particle image velocimetry (PIV). The two-dimensional (2D) system studied involves a sharp-wedge sliding against the workpiece to remove material, also reminiscent of asperity contacts in sliding. A unique feature of the study is in situ mapping of material flow at high resolution using strain fields and streaklines and simultaneous measurements of tool motions and forces, such that instantaneous forces and kinematics can be overlaid onto the chip formation process. The significant reductions in specific energy obtained when cutting with modulation are shown to be a consequence of discrete chip formation with reduced strain levels. This strain reduction is established by direct measurements of deformation fields. The results have implications for enhancing sustainability of machining processes and understanding surface deformation and material removal in wear processes.