bluuebunny/crossref_metadata_2025 huggingface dataset:
Import Restrictions and Food‐Safety Regulations: Insight from Brazil
Authors: Tosun Jale , de Moraes Marcondes Maurício
Published: November 2016

Since the 1980s, developing countries have been implementing radical reforms to increase their competitiveness in the global economy. While the increased export orientation has had positive effects on economic growth in many countries, it has also left them susceptible to external attempts to influence domestic regulatory standards. In this article, we explore a specific case that illustrates how domestic actors cope with such external pressures for regulatory reforms. We examine how domestic policymakers received the European Union's import ban on natural honey produced in Brazil and the actions they took in an attempt to have the ban lifted. The import ban triggered the creation of a new institution, the Honey Chamber, which helped to coordinate the interests of different sectoral actors, thereby helping to overcome institutional fragmentation. Once established, the new institution facilitated the revision of the existing regulatory standards and paved the way for the more‐rigorous monitoring of residues in honey.
The Growing Presence of Canadian Mining Companies in Mexico and the Dominance of Mexican Business Groups
Authors: Gutiérrez Haces María Teresa
Published: November 2016

This article examines the changes in the Mexican mining sector over the past 20 years resulting from the implementation of more than 19 economic agreements endorsed by the Mexican government. The analysis highlights how the protection that these instruments have provided to the movement of North American capital has facilitated the positioning of Canadian mining companies through direct investment or co‐investment projects with Mexican and foreign companies. Unlike in other Latin American countries with an important extractive industry and a clear dominance of foreign investment, since 1994, Mexican and Canadian capitals have been relatively complementary, although Mexican mining companies continue to dominate the mining industry. Finally, the article examines the 2013 constitutional energy reform and its effects on the mining activity.
Determinants, Boundaries, and Patterns of Canadian Mining Investments in Latin America (1995–2015)
Authors: Heidrich Pablo
Published: November 2016

As part of the commodities boom that Latin America enjoyed in the first decade of the twenty‐first century, Canadian investments in metal mining expanded there at an extraordinary pace, determined by a larger process of industrial consolidation and long‐term Canadian government policies to support the internationalization of its industry. Their success in Latin America has now induced some observers to believe that Canada is a dominant actor in that region's mining sector, but the specialization of Canadian firms in precious metals, gold and silver, has set up clear boundaries to their regional relevance, rendering Canadian capital necessary but not an essential actor in the Latin American mining boom. In fact, such pattern of specialization has turned the expansion of Canadian mining capital into a significant exposure to Latin American politics that Ottawa's government and diplomacy can affect only marginally.
Risk of empyema in patients with chronic liver disease and cirrhosis: A nationwide, population‐based cohort study
Authors: Shen Te‐Chun , Chen Chia‐Hung , Lai Hsueh‐Chou , Lin Cheng‐Li , Tu Chih‐Yen , Hsia Te‐Chun , Shih Chuen‐Ming , Hsu Wu‐Huei , Sung Fung‐Chang
Published: November 2016

Background

Empyema is an important complication for patients with chronic liver disease and cirrhosis (CLDC). However, no study has investigated this relationship by using a population‐based cohort study.

Methods

We used the National Health Insurance Research Data of Taiwan to identify a cohort of 76 027 CLDC patients newly diagnosed in 2000‐2010 and a comparison cohort without CLDC of same size matched by age, gender and the year of diagnosis. The occurrence of empyema was monitored until the end of 2011. The hazard ratios (HRs) of empyema were estimated using the Cox model.

Results

The overall incidence of empyema was 66% greater in the CLDC group than in the non‐CLDC group (3.85 vs 2.32/10 000 person‐years, P<.001), with an adjusted HR of 1.54 (95% confidence interval [CI]=1.24‐1.90). Compared with those without CLDC, adjusted HRs of empyema were 4.96 (95% CI=3.40‐7.24) for patients with cirrhosis and 4.75 (95% CI=3.11‐7.24) for patients with alcoholic CLDC. Further analyses revealed significant adjusted HRs of empyema among CLDC patients with ascites (5.76, 95% CI=4.13‐8.04) and with gastrointestinal haemorrhage (1.60, 95% CI=1.03‐2.48), compared to those without the respective disorders. Analyses using propensity score matched CLDC and non‐CLDC cohorts revealed similar results.

Conclusion

The present study shows that CLDC patients have an increased risk of empyema. These patients need timely monitor for the risk of empyema, particularly for those with comorbid cirrhosis, alcoholic disorder, gastrointestinal haemorrhage and ascites.
Forceful Self-Help and Private Voice: How Schauer and McAdams Exaggerate a State's Ability to Monopolize Violence and Expression
Authors: Ellickson Robert C.
Published: November 2016

Frederick Schauer's The Force of Law (2015) and Richard McAdams's The Expressive Powers of Law (2015) are noteworthy contributions. However, both authors exaggerate the importance of law, as opposed to other means of social control. Schauer largely omits the role that self-help measures, ranging from negative gossip to violent self-defense, play in deterring misconduct. Contrary to Max Weber, the state in practice cannot monopolize the legitimate use of physical force. McAdams valuably analyzes law's potentially expressive effects. He might have devoted more attention, however, to identifying the contexts in which state speech tends to be more salient than private speech, such as a statement by the pope or another esteemed private pundit.
Empowering women to breastfeed: Does the Baby Friendly Initiative make a difference?
Authors: Groleau Danielle , Pizarro Katherine W. , Molino Luisa , Gray‐Donald Katherine , Semenic Sonia
Published: November 2016

The Baby‐Friendly Hospital Initiative (BFI) is currently presented worldwide as the gold standard model of care for promoting and supporting breastfeeding. However, there is a lack of understanding about the ways in which health services, including the BFI, address the cultural change from a disembodied practice (formula feeding) to an embodied one (breastfeeding) in contexts where formula feeding is the norm. We used a qualitative case study methodology to compare the embodied experience of breastfeeding and the maternal experience of breastfeeding promotion and support services between mothers receiving care from institutions with low and high levels of BFI implementation in Québec, Canada. A total of 11 focus groups were conducted with mothers from six institutions–three with high and three with low levels of BFI implementation. We found the flexible approach to breastfeeding duration, characteristic of BFI services in our study, helped to avoid maternal guilt and shame; the shift to focusing on potential barriers and strategies for overcoming them empowered women to negotiate changes in infant feeding with others and self by addressing the embodied experience of a practice that may not feel natural at the beginning. Findings have implications for the concept of habitus and the construction of the breastfeeding body; we suggest that habitus can change if agents are provided with discursive tools to negotiate this embodied change. Implications for BFI services include the need to implement the 10 steps in a flexible, family‐centred way that focuses on empowering women rather than simply reaching outcomes.
Effect of tailored dietary guidance for pregnant women on nutritional status: A double‐cohort study
Authors: Haruna Megumi , Shiraishi Mie , Matsuzaki Masayo , Yatsuki Yuko , Yeo SeonAe
Published: November 2016

This double cohort study aimed to evaluate the effect of tailored dietary guidance for pregnant women on dietary intake, nutritional status, and infant birth weight. Healthy pregnant women were recruited at an antenatal clinic during two phases over 2 years. The historical controls were analyzed a year prior to the intervention group. In both groups, data were collected at 19–26 gestational weeks (baseline) and at 34–37 gestational weeks (outcome measurement). The intervention included the following: (a) assessments of maternal dietary nutritional intake using the brief self‐administered diet history questionnaire, (b) individual feedback based on the assessments of maternal nutritional status, (c) tailored guidance for a healthy diet, (d) original cooking recipes, and (e) goal sharing. Mann–Whitney U test was used to compare the outcome data between the groups. Of the 378 eligible women, 309 women had follow‐up questionnaire data. Blood samples were obtained from 202 women. Despite a lack of improvement in reported dietary intake, plasma eicosapentaenoic acid (p = .002), docosahexaenoic acid (p < .001), arachidonic acid (p < .001), and dihomo‐gamma‐linolenic acid (p < .001) concentrations as well as maternal weight gain (p = .019) were significantly higher in the intervention group. However, serum folate (p = .031) concentration was significantly lower in the intervention group, and there were no significant differences between the groups in 25‐hydroxy vitamin D levels, blood count, average birth weight, and rate of low birth weight infants. Assessment‐based tailored guidance individualized to maternal dietary intake might partially contribute to improved nutrition in pregnant women.
Effect of iron supplementation during lactation on maternal iron status and oxidative stress: A randomized controlled trial
Authors: Jorgensen Josh M. , Yang Zhenyu , Lönnerdal Bo , Chantry Caroline J. , Dewey Kathryn G.
Published: November 2016

We examined the effect of iron‐containing prenatal vitamin–mineral supplements taken postpartum on biomarkers of iron status and oxidative stress. Lactating women (n = 114) were randomly assigned to consume daily one iron‐free prenatal vitamin–mineral supplement plus either 27 mg of iron or placebo for approximately 3.5 months. The placebo group took the tablets between meals, while those given iron took the tablets either with (Fe‐W) or between meals (Fe‐B). Blood and urine samples were collected before and after the supplementation period to analyze hemoglobin (Hb), ferritin, hepcidin, transferrin saturation (TfSat), total plasma iron, and biomarkers of oxidative stress (isoprostane and 8‐hydroxy‐2‐deoxyguanosine (8‐OHdG)) and inflammation (C‐reactive protein (CRP) and alpha‐1‐acid glycoprotein (AGP)). There was a trend toward a greater change in Hb among women in the Fe‐B group compared to placebo (+2.5 vs. −3.7 g/L, respectively, p = 0.063). When the iron groups were combined, there was a greater change in Hb (+1.4 g/L) compared to placebo (p = 0.010). There were trends toward greater changes in TfSat (p = 0.087) and total plasma iron (p = 0.065) in the iron groups compared to placebo, yet no significant differences between the three groups in change in hepcidin (p = 0.291), isoprostane (p = 0.319), or 8‐OHdG (p = 0.659), nor in change in ferritin among those with elevated CRP at baseline (60% of women; p = 0.946); among those without elevated CRP (40% of women), ferritin increased more in the iron groups compared to placebo (p = 0.001). Iron consumption during lactation moderately increased iron status, particularly among women without elevated CRP, and increased Hb, but did not significantly increase oxidative stress.
Promoting global understanding: The rewards and challenges of faculty–student collaborative research
Authors: BROOKS B. B.
Published: November 2016

Collaborative research is an integral part of interdisciplinary anthropological inquiry. Applied anthropological perspectives and collaborative research are instrumental in gaining greater understanding of cultural beliefs. Students from East Carolina University in the Global Understanding program obtain a broad educational background that emphasizes cultural diversity by completing a collaborative project with a student from a partner university. Collaborative projects on cross‐cultural definitions of success are discussed to demonstrate the strengths and challenges of faculty–student collaborative research. Another program offered at East Carolina that is an example of faculty–student collaborative research is the Peru Study Abroad. Students engage with local community members to gather cultural data on various topics that yielded fascinating results that helped students to understand the Andean worldview. The rewards and the challenges of faculty–student collaborative work will be discussed in terms of student learning outcomes and cultural beliefs. [higher education, collaborative research, cultural beliefs]
Creating a better tomorrow: Teaching applied cultural anthropological research by reimagining service learning and community engagement
Authors: COPELAND TONI , PLOESSL DONNA , MCNEECE AVERY , KENNETT CURTIS , LEE VICTORIA , KARGES DYLAN , LYLES HEATHER
Published: November 2016

Service learning combines classroom instruction with meaningful community service. This article presents a project grounded in this concept that developed in a graduate‐level Applied Cultural Anthropology class to provide students the opportunity to learn by applying textbook information and anthropological methods to real world issues. Anthropology students researched elementary school children's concept of the future of their community. This article documents those perspectives. Graduate students visited local elementary schools and interviewed fourth graders, asking them to reflect on their city, design an ideal future community, and portray these in artwork. The project focuses on initiated change and encourages community engagement and partnerships between schools, higher education, and various community members. Outcomes include a coloring book, an illustrated report, and an instruction manual for conducting similar projects. Anthropology students benefitted in numerous ways, including a better understanding of applied anthropology and methodology as well as knowledge and experience.
Anthropology is elemental: Anthropological perspective through multilevel teaching
Authors: FUNKHOUSER J. Lynn , FRIEL JULIANN , CARR MELINDA , LIKOS KELLY , LYNN CHRISTOPHER D.
Published: November 2016

Modern academia is a concomitant venture involving research, teaching, and service. This article outlines a reimagined service‐learning project that provides research and teaching experience to undergraduate and graduate anthropology students. We teach graduate students to teach undergraduates to teach anthropology to elementary school children. We outline benefits of teaching anthropology to children who are considerably younger than the traditional undergraduate student—benefits to the children and to the undergraduate and graduate instructors. We examine student outcomes at the primary and university level and demonstrate how teaching can help university students more deeply integrate research experiences. While not without impediments, we propose this approach as an educational partnership model that can be adapted to suit any elementary school. Teaching anthropological research in elementary schools exposes a more diverse demographic of students to concepts including evolution, race as a cultural construct, and the impact of culture on humans. [applied anthropology, primary education, service learning]
A web app for population viability and harvesting analyses
Authors: GETZ WAYNE M. , MUELLERKLEIN OLIVER C. , SALTER RICHARD M. , CARLSON COLIN J. , LYONS ANDREW J. , SEIDEL DANA P.
Published: November 2016

Population viability analysis (PVA) is used to assess the probability that a biological population will persist for a specified period of time. Such models are typically cast as Markov processes that may include age, stage, sex and metapopulation structures, density‐dependence and ecological interaction processes. They may also include harvesting, stocking, and thresholds that trigger interventions. Here we present a PVA web app that includes extensible user‐selected options. Specifically, this PVA web app allows for the specification of one to ten age classes, one or two sexes, single population or metapopulation configurations with 2 or 3 subpopulations, as well as density‐dependent settings for inducing region‐specific carrying capacities. Movement among subpopulations can be influenced by age, metapopulation connectivity, and attractivity of regions based on the relative fitness of the youngest age classes in each region. Simulations can be carried out deterministically or stochastically, with a user‐specified combination of demographic and environmental processes. This PVA web app is freely available athttp://www.numerusinc.com/webapps/pvafor running directly on any browser and device. It is easily modified by users familiar with the NovaModeler Software Platform.
On the pathogenesis of mTOR inhibitor‐associated stomatitis (mIAS)—studies using an organotypic model of the oral mucosa
Authors: Sonis S , Andreotta PW , Lyng G
Published: November 2016

Objective

mTOR inhibitor treatment of solid cancers is associated with mTOR inhibitor‐associated stomatitis (mIAS) a common, significant, dose‐limiting toxicity, with aphthous‐like lesions. Our objective was to assess the utility of a new organotypic model in defining mIAS’ pathogenesis.

Materials and methods

The effect of everolimus on organotypic human oral mucosa was studied. Sterile specimens were assessed 24 and 48 h after exposure to varying concentrations of everolimus. Morphologic changes and measures of apoptosis, proliferation, and levels of six Th1 and Th2 cytokines were studied.

Results

Following a 24‐h incubation, concentrations of 500 ng ml−1 of everolimus resulted in histological changes consistent with epithelial injury, disorganization and pre‐ or early apoptosis, increased TUNEL‐positive staining (P < 0.05) and reduced PCNA‐positive staining cells (P < 0.001) and increased levels of IL‐6 (P < 0.0001), IL‐8 (P < 0.01), and IFN‐γ (P < 0.09).

Conclusions

Everolimus elicited epithelial damage manifest by morphologic changes, increased apoptosis, and decreased proliferation with concurrent release of keratinocyte‐derived pro‐inflammatory cytokines in the absence of bacteria. The extent of the effect was concentration and time dependent. These results suggest that mIAS is likely initiated by direct epithelial injury, independent of the microbiome. Keratinocyte cytokine release could likely play a role in accelerating an inflammatory infiltrate.
Functional flower traits and their diversity drive pollinator visitation
Authors: Fornoff Felix , Klein Alexandra‐Maria , Hartig Florian , Benadi Gita , Venjakob Christine , Schaefer H. Martin , Ebeling Anne
Published: November 2016

Recent studies have shown that the diversity of flowering plants can enhance pollinator richness and visitation frequency and thereby increase the resilience of pollination. It is assumed that flower traits explain these effects, but it is still unclear which flower traits are responsible, and knowing that, if pollinator richness and visitation frequency are more driven by mass‐ratio effects (mean trait values) or by trait diversity.

Here, we analyse a three‐year data set of pollinator observations collected in a European grassland plant diversity experiment (The Jena experiment). The data entail comprehensive flower trait measurements, including reward traits (nectar and pollen amount), morphological traits (height, symmetry, area, colour spectra) and chemical traits (nectar‐amino acid and nectar‐sugar concentration). We test if pollinator species richness and visitation frequency of flower communities depend on overall functional diversity combining all flower traits within a community, single trait diversities (within trait variation) and community‐weighted means of the single traits, using Bayesian inference.

Overall functional diversity did not affect pollinator species richness, but reduced visitation frequency. When looking at individual flower traits separately, we found that single trait diversity of flower reflectance and flower morphology were important predictors of pollinator visitation frequency. Moreover, independent of total flower abundance, community‐weighted means of flower height, area, reflectance, nectar‐sugar concentration and nectar‐amino acid concentration strongly affected both pollinator species richness and visitation frequency.

Our results, challenge the idea that functional diversity always positively affects ecosystem functions. Nonetheless, we demonstrate that both single trait diversity and mass‐ratio effects of flower traits play an important role for diverse and frequent flower visits, which underlines the functionality of flower traits for pollination services.
Spread of exotic grass in grazed native grass pastures and responses of insect communities
Authors: Monroe Adrian P. , Hill JoVonn G. , Martin James A.
Published: November 2016

Exotic grasses are widely established across the Southeastern United States for livestock forage, resulting in the structural and compositional simplification of grasslands. Replacing exotic forages with native warm‐season grasses (NWSG) could benefit insects due to increased complexity of plant structure and composition, but livestock grazing also may facilitate spread of remnant exotic grasses such as bermudagrass (Cynodon dactylon) by reducing height and coverage of NWSG. We investigated these relationships among 12 operational‐scale pastures (6.4–10.5 ha) in Mississippi, U.S.A., during May–July (2011–2012). We quantified changes in bermudagrass coverage from one treatment of grazed exotic forages and three treatments of recently established NWSG, including a grazed mixed NWSG polyculture, a grazed Indian grass (Sorghastrum nutans) monoculture to evaluate the effects of stand‐type richness among NWSG pastures, and a non‐grazed NWSG polyculture to evaluate the effects of grazing. We also assessed responses of two insect orders, Orthoptera and Hemiptera, to treatment and bermudagrass coverage. We estimated a 101–190% average increase in coverage of bermudagrass in grazed native grass pastures (NWSG polyculture and Indian grass monoculture), but not in non‐grazed NWSG, suggesting that grazing facilitated the spread of this grass. Composition of Orthopteran and Hemipteran communities was correlated with bermudagrass coverage, and inter‐year differences in composition for both communities in grazed mixed NWSG, and for Hemiptera in grazed Indian grass, corresponded with increasing bermudagrass coverage in those treatments. Our results suggest that incomplete eradication of exotic forages prior to establishment of NWSG may be exacerbated by grazing, which could then impact stand condition and insect communities.
Authoritarianism as a Research Constraint: Political Scientists in China*
Authors: Reny Marie‐Eve
Published: November 2016

Objective

This article examines the ways the authoritarian nature of the regime in the People's Republic of China constrains the conduct of political science research. It further seeks to identify ways in which researchers have circumvented authoritarian controls.

Methods

The article examines existing scholarly literature and curricula pertaining to Chinese politics to identify methodological and technical tendencies in the research field. It then conducts a deeper, theoretical investigation to show how researchers exploit loopholes and blindspots in the authoritarian system to generate novel research.

Results

The study finds a marked propensity in the study of Chinese politics toward qualitative research. Research on local politics is considered less sensitive and thus is more prevalent than studies of the central government. Government restrictions have forced scholars to imperfect data for empirical support.

Conclusion

Although it is easier to generate new findings in politically open settings, the authoritarian nature of the Chinese regime does not necessarily hinder advancement in social science. Quantitative research that relies on government‐issued data is useful, but remains liable to government restriction. Qualitative and ethnographic research gives the researcher opportunities to bypass restrictions imposed by the regime. These opportunities depend upon the researcher's ability to immerse herself in the relevant communities, find reliable and context‐aware collaborators, and develop creative ways of collecting information about state behavior.
Regimes and Randomization: Authoritarianism and Field Research in Contemporary Kenya*
Authors: Sheely Ryan
Published: November 2016

Objectives

Little is known about how the legacy of authoritarian politics shapes research in countries that have recently transitioned to democracy. How do previous periods of authoritarian rule shape field research that takes place after a regime transition? To what extent are authoritarian tendencies present in the practice of quantitative field research in a democracy?

Methods

I engage in a reflexive and historical analysis of a number of episodes of field research in Kenya. I describe and categorize the two authoritarian political regimes that have governed Kenya: the colonial regime that governed the country from the early 20th century to independence in 1963 and the bureaucratic executive authoritarian regime that governed the country from 1963 until the 2002 election. I then analyze how the historical legacy of each of these regimes shapes the practice of research in contemporary Kenya, using both my own experiences and historical examples.

Results

My results indicate that although the liberalization of the Kenyan regime over the past 20 years has permitted the expansion of social science research in the country, authoritarian institutions and practices continue to shape field research in the country in two ways. First, the institutional legacies of Kenya's previous authoritarian regimes continue to shape field research by informally shaping the behavior of both public officials and ordinary citizens. Second, the practice of randomized field research can lead to the reinforcement of authoritarian cultural practices and social norms by emphasizing centralization, control, and compliance rather than democratic norms of deliberation, participation, and collective ownership.

Conclusions

Both types of authoritarian influences on field research pose both methodological and ethical problems for field researchers in Kenya and other countries that have recently experienced regime change. I summarize the methodological and normative implications of these findings and provide a set of recommendations for field researchers.
Archivists and Adventurers: Research Strategies for Authoritarian Regimes of the Past and Present*
Authors: Art David
Published: November 2016

Objective

To analyze the theoretical and political stakes involved in researching authoritarian regimes.

Method

A meta‐analysis of recent books and articles on authoritarianism, including the articles in this special volume.

Results

The prevailing research methods set unrealistic standards for analyses of authoritarianism, with serious consequences for theory building and American foreign policy.

Conclusion

The old rules of fieldwork still apply, and scholars are well advised to develop tactics and “work‐arounds” to meet the inherent challenge of discovering useful knowledge about authoritarian regimes. Historical cases of authoritarianism also provide an underused resource for theory development and testing.
On the Outside Looking In: Secrecy and the Study of Authoritarian Regimes*
Authors: Barros Robert
Published: November 2016

Objective

This study seeks to show how authoritarian secrecy complicates the reliable identification of the inner power configuration in dictatorships. This topic is relevant to recent research on autocratic regime subtypes and institutions.

Methods

The study pursues a theoretical and conceptual analysis of the implications of heteronomous structures of authoritarian power for: the opportunity and motive of autocrats to employ secrecy; the reliability of indirect types of evidence, such as the observable presence of institutions, legislation, or the regime's self‐presentation through media, speeches, and interviews; and the production and preservation of direct sources.

Results

I find that autocratic secrecy presents considerable obstacles for studying the highest levels of authoritarian power; that indirect forms of evidence are equivocal sources; and that, ultimately, we need to know how dictatorships actually operate to reliably classify regimes.

Conclusions

Secrecy creates methodological problems for the study of autocracies that are largely absent in the study of democracies.
Standing in the Shadows of Obesity: The Local Food Environment and Obesity in Detroit
Authors: Ledoux Timothy F. , Vojnovic Igor , Manning Thomas June , Pothukuchi Kameshwari
Published: November 2016

Much of the literature examining associations between local food environments and obesity fail to consider whether or not respondents actually utilise the food stores around them. Drawing on survey data, this study examines the relationships between the neighbourhood food environment, mobility and obesity among residents from the lower eastside neighbourhoods of Detroit, Michigan. Certain dimensions of the local food environment are found to contribute to obesity, but these dimensions occur at different scales. Residents who rely on their immediate neighbourhood food environment have a higher likelihood of being obese than residents who do not utilise the stores around them. At a broader level, lower eastside Detroit residents with a greater concentration of fast food establishments around them have a higher possibility of being obese than residents with fewer fast food restaurants around them. The salience of the fast food environment warrants additional attention in terms of public health interventions.
Characterization of a novel form of progressive retinal atrophy in Whippet dogs: a clinical, electroretinographic, and breeding study
Authors: Somma André Tavares , Moreno Juan Carlos Duque , Sato Mario Teruo , Rodrigues Blanche Dreher , Bacellar‐Galdino Marianna , Occelli Laurence Mireille , Petersen‐Jones Simon Michael , Montiani‐Ferreira Fabiano
Published: November 2016

Objective

To describe a form of progressive retinal atrophy (PRA) in Whippets including clinical, electroretinographic, optical coherence tomographic changes and pedigree analysis.

Animals studied

Client‐owned Whippet dogs (n = 51) living in Brazil.

Procedures

All animals were submitted for routine ophthalmic screening for presumed inherited ocular disease, which included the following: visual tests, such as obstacle course tests, in scotopic and photopic conditions, cotton ball test, dazzle reflex, ocular fundus evaluation by indirect ophthalmoscopy followed by fundus photography. Additionally, electroretinography (ERG) and optical coherence tomography (OCT) were performed in 24 and four dogs, respectively.

Results

Sixteen dogs were diagnosed with PRA. Vision deficits in dim light were detected in dogs examined at a young age associated with nystagmus. Funduscopic changes included the development of multifocal retinal bullae from 6 months of age. Retinal thinning became apparent later, at which time the bullae were no longer detected. OCT examination of selected young dogs revealed that the retinal bullae were due to separation between photoreceptors and the retinal pigment epithelium, and of dogs with more advanced disease confirmed the development of retinal thinning. Electroretinography in young dogs revealed a negative ERG due to a lack of b‐wave in both scotopic and photopic recordings. With progression, the ERG became unrecordable. Pedigree analysis suggested an autosomal recessive mode of inheritance.

Conclusion

The retinal dystrophy reported here in Whippet dogs has a unique phenotype of an initial lack of ERG b‐wave, development of retinal bullae then a progressive generalized retinal degeneration.
The effects of LT-SN on energy dissipation and lifetime in wireless sensor networks
Authors: Pala Zeydin
Published: November 2016

Wireless sensor networks (WSNs) still attract the attention of researchers, users and the private sector despite their low power and low range tendency for malfunction. This attraction towards WSNs results from their low cost structure and the solutions they offer for many prevalent problems. Many conditions, which remain unforeseen or unexpected during the design of the system, may arise after the initialization of the system. Similarly, many situations where security vulnerabilities take place may emerge in time in WSNs operating normally. In this study, we called nodes which enter sleeping mode without any further waking up and causing a sparser number of nodes in the network without any function in data transmission as Long-Term Sleep Nodes (LT-SN); and considered energy spaces caused by such nodes as a problem; and established two Linear Programming (LP) models based on the efficiency of the present nodes. We offered two different models which present the effect of sensor nodes, which were initially operating in wireless sensor network environment and did not wake up following sleep mode, on network lifetime. The results of the present study report that as the number of LT-SN increases, the lifetime of the network decreases.
Estimation of Elastic Parameters of Sandwich Composite Plates Using a Gradient Based Finite Element Model Updating Approach
Authors: Mondal Subhajit , Chakraborty Sushanta , Mitra Nilanjan
Published: November 2016

The dynamic behavior of sandwich composite structures needs to be predicted as accurately as possible for ensuring safety and serviceability. A properly converged finite element model can accurately predict such behavior, if the current material properties are determined within very close ranges to their actual values. The initial nominal values of material properties are guessed from established standards or from manufacturer’s data, followed by verification through quasi-static characterization tests of extracted samples. Such structures can be modal tested to determine the dynamic responses very accurately, as and when required. A mathematically well posed inverse problem can thus be formulated to inversely update the material parameters accurately from initial guesses through finite element model updating procedures. Such exercise can be conveniently used for condition assessment and health monitoring of sandwich composite structures. The method is capable of determining the degradation of material properties, hence suitable for damage detection. The in-plane as well as out-of-plane elastic moduli can be determined to predict the actual responses which can be verified by physical measurement. In the present investigation, the in-plane and out-of-plane elastic parameters of the face sheets made of glass fiber reinforced plastics, i.e. E1, E2, G12, G13, G23 of the face sheet and the Young’s modulus (E) of the core of a sandwich composite plate has been determined inversely from available modal responses. The method is based on the correlation between the dynamic responses as predicted using finite element model and those measured from modal testing to form the objective function, sensitive enough to the in-plane and out-of-plane material constants. A gradient based Inverse Eigensensivity Method (IEM) has been implemented to identify these material parameters of a rectangular sandwich composite plate from natural frequencies. It may be noted that the initial characterization test data may not be useful in predicting accurate dynamic responses of existing degraded sandwich structures, if the material constants have changed substantially. Destructive characterization test on existing structure is mostly not permitted as samples need to be extracted which may damage the otherwise intact structure.
Interface Waves in Hybrid Metal-Composite Structures
Authors: Jahanbin Mohammadreza , Santhanam Sridhar , Ihn Jeong-Beom
Published: November 2016

Damage nucleation and growth can be complex in hybrid structures composed of layers of metal and laminated composites. Presently there are limited reliable damage growth analytical and empirical methods to evaluate the bond integrity of such structures and to quantify the state of bonding in such joints. Depending on the geometry and accessibility of hybrid joints, ultrasonic nondestructive testing (NDT) techniques are available for inspection of these structures. However there are some limitations for the usage of typical bulk or guided waves to quantify the integrity of bondline in hybrid structures. This work suggests the use of specific forms of ultrasonic guided waves that propagate along the bondline of these hybrid structures. This study is dedicated to modeling of interface guided waves for the purpose of disbond crack damage assessment. The nature of interface waves is discussed and the numerical simulation based on the material properties and geometries of hybrid interfaces as well as composite stacking sequence is verified. A finite element model of a hybrid structure with isotropic and anisotropic multilayer composites is constructed. The behavior of interface guided waves influenced by disbond cracks at free edges of hybrid bonded joints is numerically studied. The propagation characteristics of interface waves is shown to be sensitive to the size of disbond cracks. The velocity of interface waves is shown to have an inverse relation to the disbond damage size. Results show the speed is also a function of the interfacing ply orientation at the bondline. These results suggest that interface waves can be used to monitor the condition of bonded joints in hybrid structures.
Analysis and Design of a Shape Memory Alloy Actuated Arm to Replicate Human Biomechanics
Authors: Wright Cody , Bilgen Onur
Published: November 2016

Shape memory alloy actuators paired in an antagonistic arrangement can be used to produce mechanisms that replicate human biomechanics. To investigate this proposal, the biomechanical articulation of the elbow by means of the biceps brachii muscle are compared with that of a shape memory alloy actuated arm. Initially, the movement of the human arm is modeled as a single degree of freedom rocker-slider mechanism. Using this model, a purely kinematical analysis is performed on the rigid body rocker-slider. Force analysis follows by modeling the muscle as a simple linear spring. Torque, rocking angle, and energy are calculated for a range of rocker-slider geometries. Actuator characterization of the SMA wire is conducted by experimentally determining the stress-strain curves for the martensite detwinned and full austenite states. Using the experimentally obtained stress-strain curves, nonlinear and linear theoretical actuator characteristic curves are produced for the isolated SMA wire. Using the theoretical actuator characteristic curve on the rocker-slider mechanism, kinematic and force analyses are performed for both the nonlinear and linear actuated mechanisms. To compare to biomechanics, a literature survey is performed on human musculotendon and skeletal lengths and introduced to the kinematic analysis. Examination of biological and mechanical results are then discussed.
Nanocomposite Fabric Sensors for Monitoring Inflatable and Deployable Space Structures
Authors: Wang Long , Gupta Sumit , Loh Kenneth J. , Koo Helen S.
Published: November 2016

Inflatable deployable structures are practical and promising candidates for serving various aerospace missions, for instance, as solar sails, antennas, space suits, and especially Lunar and Mars habitats. These structures feature flexible composites folded at high packing efficiency, which can drastically reduce launch costs. However, they can also be damaged due to the harsh extraterrestrial operating conditions, which can propagate to cause catastrophic mission failure and endanger crew safety. Therefore, it is imperative to integrate a robust structural health monitoring (SHM) system, so that damage and faults can be detected for ensuring their safe and reliable operations. While a variety of SHM technologies have been developed for monitoring conventional, rigid, structural systems, they are faced with challenges when used for these unconventional flexible and inflatable systems. Therefore, a flexible carbon nanotube-fabric nanocomposite sensor is proposed in this study for monitoring the integrity of inflatable space structures. In particular, CNT-based thin films were fabricated by spraying and then integrated with flexible fabric to form the lightweight sensor. By coupling fabric sensors with an electrical impedance tomography (EIT) algorithm, the fabric’s distribution of spatial resistivity can be mapped using only electrical measurements obtained along the material’s boundaries. The severity and location of localized pressure and impact damage can be captured by observing changes in the EIT-calculated resistivity maps. They can be embedded in inflatable habitat structures to detect and locate abnormally high pressure regions and impact damage.
Characterization and Localization of Sub-Surface Structural Features Using Non-Contact Tomography
Authors: Gupta Sumit , Loh Kenneth J.
Published: November 2016

The main objective of this work is to develop a non-contact, non-invasive, structural health monitoring technique for surface and sub-surface damage detection in structures such as composite helicopter rotor blades. In many cases, composite structures are prone to damage in the form of cracks, delamination, and manufacturing defects, which can propagate beneath structural surfaces and cause severe component or catastrophic structural failure. The damage detection technique in this study works on the principle of electrical capacitance tomography. Different patterns of electrical field are propagated in a pre-defined sensing area. Using measurements of electrical response along boundaries of the sensing area, the permittivity distribution within that space can be reconstructed. First, a series of numerical simulations was performed by altering the electrical permittivity at different locations to simulate damage. The shapes and locations of permittivity changes were captured by the proposed technique. Second, to demonstrate its validity, an experimental test setup was built with a set of boundary electrodes. The system was connected to a function generator that supplied an electrical signal and induced electrical fields between electrodes. Capacitance between pairs of electrodes were then measured, which were used as inputs for solving the inverse permittivity reconstruction problem. Various test cases with different objects placed in the sensing area were conducted for validating this technique. The preliminary results show that the system was able to reconstruct spatial permittivity distributions and detect the presence, shapes, and locations of objects, thereby suggesting potential for damage detection.
Mechanoluminescence Based Structural Health Monitoring Technique for Elastomeric Components
Authors: Krishnan Srivatsava , Sundaresan Vishnubaba
Published: November 2016

Light emission induced by mechanical input, termed mechanoluminescence (ML), has been gaining widespread attention recently. Various theories have been put forth over the years identifying sources and mechanisms behind ML. Several applications utilizing ML such as stress sensing, stress visualization, surface crack propagation detection and environmental friendly light source have been put forth. Despite promising results, large scale implementation of ML based sensing and visualization technologies for industrial applications is yet to be achieved. In this conference paper, we demonstrate a structural health monitoring technique utilizing mechanoluminescence emission that is low power, in-situ and easily scalable for industrial applications. Flexible elastomeric composite coupons impregnated with ML crystals subjected to constant cyclical loading up to millions of cycles. ML emission from the coupons is used to track the strain in the coupon over time. Variations in strain are then correlated to variations in stiffness of the coupon over time thereby monitoring its structural health. We also predict the failure of the coupons based on ML intensity. A pseudo-algorithm that tracks ML intensity and predicts failure ahead in time is also put forth facilitating convenient scale-up for industrial applications.
Feasibility Study for Vision-Based Cable Force Measurement Using Smartphone
Authors: Zhao Xuefeng , Ri Kwang , Yu Yan , Kang Chunil , Li Mingchu , Ou Jinping
Published: November 2016

An accurate cable force measurement is one of very important practical problems during construction period as well as during service period of cable stayed bridge. In the recent years, with the advances in smartphone technologies, it is possible to rapidly evaluate structural health status and postevent damage using ubiquitous smartphones.

In this paper, a novel vision-based cable force measurement method using smartphone camera is proposed for the first time, which enable to estimate cable force by recognizing cable vibration using smartphone camera, and then cable model test is carried out to verify the feasibility of the proposed method. The comparison test between the smartphone application Orion-CC measuring cable force from smartphone built-in accelerometer and the proposed method is conducted on a laboratory scale cable model with different sampling rates.

In the proposed method, the vibration responses of cable are obtained by monitoring displacements of a preprinted black circular target attached on the cable model using smartphone camera. The test results showed satisfactory agreements between two methods in both frequency domain and cable force value, demonstrating the feasibility of the proposed cable force measurement method and its advantages such as convenience, ease of operation, and speediness.
Bridge Inspection and Management System Based on Smart Phone
Authors: Ding Yanbing , Han Ruicong , Liu Hao , Li Shengyuan , Zhao Xuefeng , Yu Yan
Published: November 2016

For the traditional inspection methods, the visual inspection data is firstly recorded on the inspection forms and then input manually into computer, which is inefficient and creates errors frequently. This research aims at establishing a smartphone-based bridge inspection and management system that can avoid such inputting errors and facilitate the bridge inspection process. The system enables the inspector to complete the inspection information collection in a portable smart phone. The site photos that related to the investigated structures can be easily added and edited during the inspection work with the help of the smart phone. After the investigation, the inspection report and the technical condition rating of the inspected bridge can be automatically generated. The collected data and the GPS information can be uploaded to the terminal server directly via the mobile network. The interface of the mobile software is user-friendly and easy operation, which provides an opportunity for the public to take part in the bridge inspection work, especially for the bridges in rural and mountainous areas. Then, this paper puts forward the relevant ideas on public participation in bridges’ emergency assessment and disposal after the disaster, which can provide data support for the decision-making and disaster relief work.