bluuebunny/crossref_metadata_2025 huggingface dataset:
Endocardium Minimally Contributes to Coronary Endothelium in the Embryonic Ventricular Free Walls
Authors: Zhang Hui , Pu Wenjuan , Li Guang , Huang Xiuzhen , He Lingjuan , Tian Xueying , Liu Qiaozhen , Zhang Libo , Wu Sean M. , Sucov Henry M. , Zhou Bin
Published: April 2016

Rationale:

There is persistent uncertainty regarding the developmental origins of coronary vessels, with 2 principal sources suggested as ventricular endocardium or sinus venosus (SV). These 2 proposed origins implicate fundamentally distinct mechanisms of vessel formation. Resolution of this controversy is critical for deciphering the programs that result in the formation of coronary vessels and has implications for research on therapeutic angiogenesis.

Objective:

To resolve the controversy over the developmental origin of coronary vessels.

Methods and Results:

We first generated
nuclear factor of activated T cells (Nfatc1)-Cre
and
Nfatc1-Dre
lineage tracers for endocardium labeling. We found that Nfatc1 recombinases also label a significant portion of SV endothelial cells in addition to endocardium. Therefore, restricted endocardial lineage tracing requires a specific marker that distinguishes endocardium from SV. By single-cell gene expression analysis, we identified a novel endocardial gene natriuretic peptide receptor 3 (Npr3). Npr3 is expressed in the entirety of the endocardium but not in the SV. Genetic lineage tracing based on
Npr3-CreER
showed that endocardium contributes to a minority of coronary vessels in the free walls of embryonic heart. Intersectional genetic lineage tracing experiments demonstrated that endocardium minimally contributes to coronary endothelium in the embryonic ventricular free walls.

Conclusions:

Our study suggested that SV, but not endocardium, is the major origin for coronary endothelium in the embryonic ventricular free walls. This work thus resolves the recent controversy over the developmental origin of coronary endothelium, providing the basis for studying coronary vessel formation and regeneration after injury.
Cannabis Use and Outcomes in Patients With Aneurysmal Subarachnoid Hemorrhage
Authors: Behrouz Réza , Birnbaum Lee , Grandhi Ramesh , Johnson Jeremiah , Misra Vivek , Palacio Santiago , Seifi Ali , Topel Christopher , Garvin Rachel , Caron Jean-Louis
Published: April 2016

Background and Purpose—

The incidence of cannabis use in patients with aneurysmal subarachnoid hemorrhage (aSAH) and its impact on morbidity, mortality, and outcomes are unknown. Our objective was to evaluate the relationship between cannabis use and outcomes in patients with aSAH.

Methods—

Records of consecutive patients admitted with aSAH between 2010 and 2015 were reviewed. Clinical features and outcomes of aSAH patients with negative urine drug screen and cannabinoids-positive (CB+) were compared. Regression analyses were used to assess for associations.

Results—

The study group consisted of 108 patients; 25.9% with CB+. Delayed cerebral ischemia was diagnosed in 50% of CB+ and 23.8% of urine drug screen negative patients (
P
=0.01). CB+ was independently associated with development of delayed cerebral ischemia (odds ratio, 2.68; 95% confidence interval, 1.03–6.99;
P
=0.01). A significantly higher number of CB+ than urine drug screen negative patients had poor outcome (35.7% versus 13.8%;
P
=0.01). In univariate analysis, CB+ was associated with the composite end point of hospital mortality/severe disability (odds ratio, 2.93; 95% confidence interval, 1.07–8.01;
P
=0.04). However, after adjusting for other predictors, this effect was no longer significant.

Conclusions—

We offer preliminary data that CB+ is independently associated with delayed cerebral ischemia and possibly poor outcome in patients with aSAH. Our findings add to the growing evidence on the association of cannabis with cerebrovascular risk.
Taxonomic review of the Neotropical genus Gephyrocharax Eigenmann, 1912 (Characiformes, Characidae, Stevardiinae)
Authors: VANEGAS-RÍOS JAMES A.
Published: April 2016

Gephyrocharax currently comprises 13 valid species distributed in the Cis- and Trans-Andean basins of the Neotropical region. The genus has not been reviewed in more than 80 years, and thus, the older species descriptions are poorly detailed, based on small samples of specimens, and supported by uninformative diagnoses. The present review is based on external morphology and morphometric, meristic, osteological, and myological data. Counts and measurements were analyzed using bivariate and multivariate statistical procedures implemented in PAST and SigmaPlot. Cases of synonyms and geographic variation were evaluated using sheared principal components analyses (SPCA). Eleven valid species are recognized for the genus: G. atracaudatus, G. caucanus, G. chocoensis, G. intermedius, G. major, G. martae, G. melanocheir, G. sinuensis, G. torresi, G. valencia, and G. venezuelae. Gephyrocharax whaleri is proposed as junior synonym of G. intermedius, and Corynopomops opisthopterus and G. chaparae are proposed as junior synonyms of G. major. A lectotype for G. major and neotypes for G. melanocheir and G. sinuensis are designated. Gephyrocharax atracaudatus is confirmed for the first time in the Palenque River basin of the Pears islands in the Gulf of Panama. New distributional records are reported for G. major in the Amazon River basin. Gephyrocharax major and G. valencia are the most widely distributed members of the genus. Distributional and georeferenced maps are presented for all Gephyrocharax species based on extensive examined material. An identification key of the Gephyrocharax species is provided.
Revision of the subgenus Aleochara Gravenhorst of the parasitoid rove beetle genus Aleochara Gravenhorst of Japan (Coleoptera: Staphylinidae: Aleocharinae)
Authors: YAMAMOTO SHÛHEI , MARUYAMA MUNETOSHI
Published: April 2016

The Japanese members of the subgenus Aleochara Gravenhorst, 1802 of the genus Aleochara Gravenhorst, 1802 are revised. Six species are recognized: Aleochara (Aleochara) coreana Bernhauer, 1926; A. (A.) curtula (Goeze, 1777); A. (A.) lata Gravenhorst, 1802; A. (A.) parens Sharp, 1874; A. (A.) postica Walker, 1858 [= A. (A.) clavigera Sharp, 1874, n. syn.; A. (A.) nitouensis Bernhauer, 1935, n. syn.; A. (A.) marginicollis Cameron, 1942, n. syn.], and; A. (A.) yaeyamensis n. sp. (Yaeyama Islands, the Ryûkyûs). We recognize A. niponensis Sharp, 1888, sp. rev., currently synonymized under A. clavigera, as a valid species and transfer it to the subgenus Xenochara Mulsant & Rey, 1874. “A. (A.)” kochi Bernhauer, 1941 [=“A. (A.)” globus Pace, 1999, n. syn.] is excluded from Aleochara and re-assigned instead to Paraleochara Cameron, 1920. Paraleochara is new to the Palearctic region, and Paraleochara kochi (Bernhauer, 1941), n. comb. represents the second species of the genus. Lectotypes of A. niponensis, A. parens, and A.discoidea are designated. All species are described, keyed, and figured, with habitus photographs. Line drawings of the adult mouth parts of A. (A.) curtula (Goeze, 1777) are shown. The diversity, distribution, and phylogenetic relationships of the subgenus in Japan are also discussed.
The Australian Monstrilloida (Crustacea: Copepoda) II. Cymbasoma Thompson, 1888
Authors: SUÁREZ-MORALES EDUARDO , MCKINNON A. DAVID
Published: April 2016

Monstrilloid copepods collected during the past two decades from zooplankton surveys in reef and coastal areas of Australia were analyzed. A first contribution included the taxonomic analysis of three genera of the Monstrilloida, Monstrillopsis Sars, 1921, Maemonstrilla Grygier & Ohtsuka, 2008, and the newly described Australomonstrillopsis Suárez-Morales & McKinnon, 2014. In this document a taxonomic analysis of the species belonging to the genus Cymbasoma Thompson, 1888 is provided. A total of 28 species were found, most of them being undescribed. Seventeen species were described based on females only and eight on male specimens while three species were described from both sexes. Males of Australian species of Cymbasoma are distinguished by details of the genital complex, body size and proportions, ornamentation and processes of the cephalic region, number of caudal setae, and the characteristic structure or ornamentation of the genital lappets. Two main groups of males were distinguished on the basis of the number of caudal setae (3 or 4). As for the females, 20 of the 25 new species of Cymbasoma have fifth legs with an unarmed inner lobe and three setae on the outer lobe; one of these species (C. jinigudira sp. nov.) belongs to the C. longispinosum species-group (sensu Üstün et al. 2014). Another group, consisting of five species, has only two setae on the outer (exopodal) lobe. There were no Australian species of Cymbasoma with a single lobe. A species group, named after C. agoense, is proposed to include species sharing a globose body and a female fifth leg with a large endopodal lobe and an outer (exopodal) lobe with two setae. The females of the new species of Cymbasoma from Australia can be distinguished from their known congeners by unique combinations of characters including the type of body ornamentation, body size and shape, antennule armature and proportions, the presence of distinctive features of the legs 1–4, the presence/absence of processes on the genital compound somite, and the presence/absence of a constriction of the anal somite. We report the occurrence of two previously described species, C. agoense Sekiguchi, 1982 from Japan and C. bali Desai & Krishnaswamy, 1962 from India in Australian waters. Considering the addition of the 25 new species here described, the number of nominal species of the genus is now 66. A key to the Australian species of Cymbasoma (males and females) and a map showing their occurrence in Australia are also provided.
Power Analysis for Models of Change in Cluster Randomized Designs
Authors: Li Wei , Konstantopoulos Spyros
Published: April 2016

Field experiments in education frequently assign entire groups such as schools to treatment or control conditions. These experiments incorporate sometimes a longitudinal component where for example students are followed over time to assess differences in the average rate of linear change, or rate of acceleration. In this study, we provide methods for power analysis in three-level polynomial change models for cluster randomized designs (i.e., treatment assigned to units at the third level). Power computations take into account clustering effects at the second and third levels, the number of measurement occasions, the impact of sample sizes at different levels (e.g., number of schools or students), and covariates effects. An illustrative example that shows how power is influenced by the number of measurement occasions, and sample sizes and covariates at the second or third levels is presented.
Virtual laboratory and learning management system in optimal control theory education
Authors: Popović Nataša , Naumović Milica B
Published: April 2016

Virtual and remote laboratories that are commonly used in engineering education are mainly designed using Java programming language. The most popular and widely used learning management system is Moodle. This paper describes the development of a virtual laboratory using Easy Java Simulations software tool and its integration with e-learning tool Moodle. The virtual laboratory demonstrates how Easy Java Simulations and Moodle are used in optimal control theory education by the example of the well-known brachistochrone problem solution.
Android-based mobile educational platform for speech signal processing
Authors: Zhao Nan , Wu Minghu , Chen Jingjing
Published: April 2016

With the purpose of further mastering and grasping the course of speech signal processing, a novel Android-based, mobile-assisted educational platform (AEPS) is proposed in this paper. The goal of this work was to design AEPS as an educational signal-processing auxiliary system by simulating signal analysis methods commonly used in speech signal processing and bridging the gap for transition from undergraduate study to industry practice or academic research. The educational platform is presented in a highly intuitive, easy-to-interpret and strongly maneuverable graphical user interface. It also has the characteristics of high portability, strong affordability, and easy adoptability for application extension and popularization. Through adequate intuitive user interface, rich visual information, and extensive hands-on experiences, it greatly facilitates students in authentic, interactive, and creative learning. This paper details a subjective evaluation of AEPS’s effectiveness as an educational tool. The result of the experiences shows that the proposed platform not only promotes the students’ learning interest and practical ability but also consolidates their understanding and impression of theoretical concepts.
Understanding political participation in West Africa: the relationship between good governance and local citizen engagement
Authors: Krawczyk Kelly Ann , Sweet-Cushman Jennie
Published: April 2016

Strengthening citizen participation in West Africa is an increasingly important aspect of democratic development – especially in mitigating setbacks arising from poor governance. This article uses Round 4 Afrobarometer data to explore what stimulates local-level participation by examining determinants against the backdrop of eight West African nations: Benin, Burkina Faso, Cape Verde, Ghana, Liberia, Mali, Nigeria, and Senegal. Using a negative binomial regression model, our results are evaluated within the framework of good governance, and show that local context, specifically relative to citizens’ perceptions of and attitudes about the performance of local government, matters when it comes to local political participation.

Points for practitioners

This study provides public administrators with a framework for understanding what drives local-level, non-electoral citizen participation in West Africa, and helps them understand how to increase local citizen engagement and build a more democratic society through the pursuit of good governance principles. In addition, this study highlights the critical importance of local government performance, and the role of citizens’ attitudes and evaluations, in local civic engagement.
Varieties of Varieties
Authors: Streeck Wolfgang
Published: April 2016

The article points out the important contribution made by the concept of “growth models” to comparative political economy (CPE). It emphasizes Baccaro and Pontusson’s critique of the standard model of “varieties of capitalism.”
Reforming the age of criminal responsibility
Authors: Crofts Thomas
Published: April 2016

This article discusses the age at which criminal responsibility should begin and whether there is still a need for the rebuttable presumption of doli incapax. It clarifies the various meanings given to the concept of the age of criminal responsibility and considers its importance. Some common law countries have moved away from the traditional position of a minimum age level of 7 years and a rebuttable presumption of doli incapax from 7 years until 14 years. In doing so, there has been a tendency to raise the minimum age of criminal responsibility to 12 years and abolish the rebuttable presumption of doli incapax. After analysising these changes, the article argues that there is still a place for this presumption unless and until the minimum age of criminal responsibility is raised to the level preferred by the United Nations Committee on the Right of the Child.
Social media and the nation state: of revolution and collaboration
Authors: Bulut Ergin
Published: April 2016

This article examines the legal infrastructure of social media governance in the politically contested context of contemporary Turkey. It looks at how social media companies (specifically, Twitter and Facebook (FB)) and the nation state (Turkey) have negotiated power in the aftermath of Gezi Uprising in Summer 2013. I argue that while today’s concerns regarding online surveillance might echo the calls for a new world information order of the 1970s, the world system model based on the core–periphery distinction has considerably changed. The useful insights of cultural imperialism fall short of explaining the geopolitical context within which Turkey finds itself in the aftermath of the Arab Uprisings and the sub-imperial relations within which she struggles to establish hegemony in the region. Findings suggest that the Turkish state tries hard to establish the legal and material infrastructure for these companies’ operations. FB is more open to cooperation with the nation state, while Twitter has chosen to legally negotiate with the government. There also seems to be major risk for activists given the contradictory articulation of nation state and corporate interests.
The practical side of working with parent–child interaction therapy with preschool children with language impairments
Authors: Klatte Inge S , Roulstone Sue
Published: April 2016

A common early intervention approach for preschool children with language problems is parent–child interaction therapy (PCIT). PCIT has positive effects for children with expressive language problems. It appears that speech and language therapists (SLTs) conduct this therapy in many different ways. This might be because of the variety of approaches available, the diverse set of families SLTs work with or the different organizational structures. Understanding the critical components of PCIT would enable SLTs to map the variations that are implemented and researchers to evaluate the effects of such variation. This study aimed to identify the potentially critical components of PCIT based on the practical experience of SLTs and to identify SLTs’ rationales for the way they structure PCIT. Both parameters are important for the long term goal, that is, to develop a framework that can be used to support practice. Semi-structured interviews were conducted with 10 SLTs who had at least one year experience in delivering PCIT with preschool children with language impairment. The interviews were transcribed and analysed, using thematic analysis. Analysis of the SLT interview data identified four potentially critical components that underpin the teaching of strategies to parents: parents’ engagement, parents’ understanding, parents’ reflection and therapists’ skills. SLTs suggested that all four components are needed for the successful delivery of PCIT. The reasons that SLTs give for the way in which they structure PCIT are mainly based on organizational constraints, family needs and practicalities. SLTs consider PCIT to be valuable but challenging to implement. A framework that makes explicit these components may be beneficial to support practice.
Autologous adipose-derived stem cells: Basic science, technique, and rationale for application in ulcer and wound healing
Authors: Zollino Ilaria , Zuolo Michele , Gianesini Sergio , Pedriali Massimo , Sibilla Maria Grazia , Tessari Mirko , Carinci Francesco , Occhionorelli Savino , Zamboni Paolo
Published: April 2016

Objectives

The present review represents a translational boundary between basic research and surgery, particularly focusing on the promising application of adipose-derived stem cells harvested intra-operatively during debridement of venous leg ulcers.

Methods

We reviewed 830 out of 5578 articles on MEDLINE starting from 1997 and sorted by the relevance option.

Results

The technique currently used for adipose-derived stem cells intra-operative harvesting is presented, including a safety evaluation on a cohort of 5089 revised patients who underwent plastic surgery and maxillo-facial surgical procedures. Complications were reported in 169 cases (3.3%). One hundred and forty-one (2.77%) patients were classified as having minor complications, specifically: nodularity/induration 93 (1.83%), dysesthesia 14 (0.26%), hematoma 12 (0.23%), superficial infection 11 (0.21%), pain 7 (0.13%), poor cosmesis 3 (0.06%), and abnormal breast secretion 1 (0.02%), while 28 patients (0.55%) were classified as having major complications, specifically: deep infection 22 (0.43%), sepsis 3 (0.06%), abdominal hematoma 2 (0.04%), and pneumothorax 1 (0.02%). Application of cell therapy in venous leg ulcer is currently used only for patients not responding to the standard treatment. The review shows the lack of randomized clinical trials for application of adipose-derived stem cells among treatments for venous leg ulcer. Finally, adipose-derived stem cells implantation at the wound site promotes a new tissue formation rich in vascular structures and remodeling collagen.

Conclusion

Adipose-derived stem cells strategy represents a great opportunity for the treatment of chronic wounds, due to the simplicity of the technique and the application of cell treatment in the operating room immediately following debridement. However, clinical studies and data from randomized trials are currently lacking.
Clinical application of Acoustic Radiation Force Impulse Imaging with Virtual Touch IQ in breast ultrasound: diagnostic performance and reproducibility of a new technique
Authors: Kapetas Panagiotis , Pinker-Domenig Katja , Woitek Ramona , Clauser Paola , Bernathova Maria , Spick Claudio , Helbich Thomas , Baltzer Pascal A
Published: April 2016

Background

Virtual Touch IQ (VTIQ) is a novel technique of quantitative sonoelastography that applies acoustic radiation force impulse (ARFI).

Purpose

To evaluate breast ARFI imaging with VTIQ in the clinical setting, with regard to reproducibility and diagnostic performance, and to specify cutoff limits for the differentiation of benign and malignant lesions.

Material and Methods

This retrospective study included 83 patients with 85 breast lesions (51 benign, 34 malignant) who received ARFI imaging with VTIQ. Two independent ARFI measurements of each lesion were performed and shear wave velocities (SWV) of the lesion and the adjacent tissues were measured. A lesion-to-fat velocity ratio (L/F Ratio) was calculated for each lesion. Diagnostic performance of SWV measurements and L/F Ratios was evaluated with receiver operating curve (ROC) analysis. The intraclass correlation coefficient and Bland–Altman plots were used to evaluate measurement reproducibility.

Results

All measurements showed equal diagnostic performance, as measured by the area under the ROC curve (0.853 for SWV, 0.882 for the L/F Ratio). At a cutoff value of 3.23 m/s, sensitivity and specificity were 82.4% and 80.4%, respectively. An L/F Ratio cutoff value of 2.23 revealed a sensitivity and specificity of 89.7% and 76.5%. The reproducibility of the SWV measurements was moderate (limits of agreement, 40.3–44.4%) and higher than that of the L/F Ratios (54.5–60.2%).

Conclusion

ARFI imaging with VTIQ is a novel, moderately reproducible, quantitative elastography technique, which provides useful information for the differentiation of benign and malignant breast lesions in the clinical setting.
Sixteen Gauge biopsy needles are better and safer than 18 Gauge in native and transplant kidney biopsies
Authors: Peters Björn , Mölne Johan , Hadimeri Henrik , Hadimeri Ursula , Stegmayr Bernd
Published: April 2016

Background

Kidney biopsies are essential for optimal diagnosis and treatment.

Purpose

To examine if quality and safety aspects differ between types and sizes of biopsy needles in native and transplant kidneys.

Material and Methods

A total of 1299 consecutive biopsies (1039 native and 260 transplant kidneys) were included. Diagnostic quality, needle size and type, clinical data and complications were registered. Eight-three percent of the data were prospective.

Results

In native kidney biopsies, 16 Gauge (G) needles compared to 18 G showed more glomeruli per pass (11 vs. 8, P <  0.001) with less complications. Sub-analysis in native kidney biopsies revealed that 18 G 19-mm side-notch needles resulted in more major (11.3% vs. 3%; odds ratio [OR], 4.1; 95% confidence interval [CI], 1.4–12.3) and overall complications (12.4% vs. 4.8%; OR, 2.8; 95% CI, 1.1–7.1) in women than in men. If the physician had performed less compared to more than four native kidney biopsies per year, minor (3.5% vs. 1.4%; OR, 2.6; 95% CI, 1.1–6.2) and overall complications (11.5% vs. 7.4%; OR, 1.6; 95% CI, 1.1–2.5) were more common. In transplant kidney biopsies, 16 G needles compared to 18 G resulted in more glomeruli per pass (12 vs. 8, P <  0.001). No differences existed in frequency of biopsy complications. The localization of performing biopsies was not a risk factor to develop complications.

Conclusion

Kidney biopsies taken by 16 G needles result in better histological quality and lower frequency of complications compared to 18 G. For native kidney biopsies the performer of the biopsy should do at least four biopsies per year.
Does the Kuleshov Effect Really Exist? Revisiting a Classic Film Experiment on Facial Expressions and Emotional Contexts
Authors: Barratt Daniel , Rédei Anna Cabak , Innes-Ker Åse , van de Weijer Joost
Published: April 2016

According to film mythology, the Soviet filmmaker Lev Kuleshov conducted an experiment in which he combined a close-up of an actor’s neutral face with three different emotional contexts: happiness, sadness, and hunger. The viewers of the three film sequences reportedly perceived the actor’s face as expressing an emotion congruent with the given context. It is not clear, however, whether or not the so-called “Kuleshov effect” really exists. The original film footage is lost and recent attempts at replication have produced either conflicting or unreliable results. The current paper describes an attempt to replicate Kuleshov’s original experiment using an improved experimental design. In a behavioral and eye tracking study, 36 participants were each presented with 24 film sequences of neutral faces across six emotional conditions. For each film sequence, the participants were asked to evaluate the emotion of the target person in terms of valence, arousal, and category. The participants’ eye movements were recorded throughout. The results suggest that some sort of Kuleshov effect does in fact exist. For each emotional condition, the participants tended to choose the appropriate category more frequently than the alternative options, while the answers to the valence and arousal questions also went in the expected directions. The eye tracking data showed how the participants attended to different regions of the target person’s face (in light of the intermediate context), but did not reveal the expected differences between the emotional conditions.
Planet Politics: A Manifesto from the End of IR
Authors: Burke Anthony , Fishel Stefanie , Mitchell Audra , Dalby Simon , Levine Daniel J.
Published: April 2016

Planet Politics is about rewriting and rethinking International Relations as a set of practices, both intellectual and organisational. We use the polemical and rhetorical format of the political manifesto to open a space for inter-disciplinary growth and debate, and for thinking about legal and institutional reform. We hope to begin a dialogue about both the limits of IR, and of its possibilities for forming alliances and fostering interdisciplinarity that can draw upon climate science, the environmental humanities, and progressive international law to respond to changes wrought by the Anthropocene and a changing climate.
Cities and Global Governance: State Failure or a New Global Order?
Authors: Curtis Simon
Published: April 2016

International society, so long the resolution to problems of collective political order, now appears to be failing in its capacity to deal with transnational challenges such as climate change, global security and financial instability. Indeed, the structure of international society itself has become a significant obstacle to such pressing issues of global governance. One striking response has been the reemergence of cities as important actors on the international stage. This article will show how these two issues are intrinsically linked. Cities have taken on new governance roles in the gaps left by hamstrung nation-states, and their contribution to an emerging global governance architecture will be a significant feature of the international relations of the 21st century. But do the new governance activities of cities represent a failure on the part of states, as some scholars have argued? Or are they a part of an emerging form of global order, in which the relationship between states, cities and other actors is being recalibrated? This article argues that the remarkable renaissance of cities in recent decades has been a result of a shift in the structure of international society, and assesses the causal drivers of this shift. It goes on to draw out some of the implications of the recalibration of the relationship between the city and the state for how we understand the emerging form of global order.
Progress in satellite remote sensing for studying physical processes at the ocean surface and its borders with the atmosphere and sea ice
Authors: Shutler Jamie D. , Quartly Graham D. , Donlon Craig J. , Sathyendranath Shubha , Platt Trevor , Chapron Bertrand , Johannessen Johnny A. , Girard-Ardhuin Fanny , Nightingale Philip D. , Woolf David K. , Høyer Jacob L.
Published: April 2016

Physical oceanography is the study of physical conditions, processes and variables within the ocean, including temperature–salinity distributions, mixing of the water column, waves, tides, currents and air–sea interaction processes. Here we provide a critical review of how satellite sensors are being used to study physical oceanography processes at the ocean surface and its borders with the atmosphere and sea ice. The paper begins by describing the main sensor types that are used to observe the oceans (visible, thermal infrared and microwave) and the specific observations that each of these sensor types can provide. We then present a critical review of how these sensors and observations are being used to study: (i) ocean surface currents, (ii) storm surges, (iii) sea ice, (iv) atmosphere–ocean gas exchange and (v) surface heat fluxes via phytoplankton. Exciting advances include the use of multiple sensors in synergy to observe temporally varying Arctic sea ice volume, atmosphere–ocean gas fluxes, and the potential for four-dimensional water circulation observations. For each of these applications we explain their relevance to society, review recent advances and capability, and provide a forward look at future prospects and opportunities. We then more generally discuss future opportunities for oceanography-focused remote sensing, which includes the unique European Union Copernicus programme, the potential of the International Space Station and commercial miniature satellites. The increasing availability of global satellite remote-sensing observations means that we are now entering an exciting period for oceanography. The easy access to these high quality data and the continued development of novel platforms is likely to drive further advances in remote sensing of the ocean and atmospheric systems.
Deliberate Rumination and Positive Reappraisal as Serial Mediators Between Life Impact and Posttraumatic Growth in Victims of State Terrorism in Chile (1973-1990)
Authors: Cárdenas Castro Manuel , Arnoso Martínez Maitane , Faúndez Abarca Ximena
Published: April 2016

This study examines the role of coping strategies related to positive reappraisal versus other cognitive strategies (deliberate rumination) as mediators between life impact and posttraumatic growth in survivors of the military dictatorship in Chile between 1973 and 1990 (tortured political prisoners and family members of political prisoners executed and missing). Survey data from 251 political violence survivors were analyzed using the SPSS PROCESS macro for bootstrapping indirect effects (Hayes, 2013). Results indicated that positive reappraisal (or reframing) coping mediated the relationship between life impact and posttraumatic growth. A serial multiple mediation model indicates that in the life impact to growth moderation process, rumination must be followed by positive reappraisal to drive this growth. These findings suggest that positive reappraisal of the traumatic experience is essential to achieve growth reports. Implications of these more complex relations are discussed for both counseling interventions and further research.
Reducing Inpatient Hospital and Emergency Room Utilization Among Nursing Home Residents
Authors: Haber Susan G. , Wensky Suzanne G. , McCall Nancy T.
Published: April 2016

Objective: To examine the association among nursing home residents between strength of relationship with a primary care provider (PCP) and inpatient hospital and emergency room (ER) utilization. Method: Medicare administrative data for beneficiaries residing in a nursing home between July 2007 and June 2009 were used in multivariate analyses controlling for beneficiary, nursing home, and market characteristics to assess the association between two measures—percentage of months with a PCP visit and whether the patient maintained the same usual source of care after nursing home admission—and hospital admissions and ER visits for all causes and for ambulatory care sensitive conditions (ACSCs). Results: Both measures of strength of patient–provider relationships were associated with fewer inpatient admissions and ER visits, except regularity of PCP visits and ACSC ER visits. Discussion: Policy makers should consider increasing the strength of nursing home resident and PCP relationships as one strategy for reducing inpatient and ER utilization.
Translating Osteoporosis Prevention Guidelines
Authors: Brennan-Olsen Sharon L. , Hosking Sarah M. , Dobbins Amelia G. , Pasco Julie A.
Published: April 2016

Objective: In Australia, the social gradient of chronic disease has never been as prominent as in current times, and the uptake of preventive health messages appears to be lower in discrete population groups. In efforts to re-frame health promotion from addressing behavior change to empowerment, we engaged community groups in disadvantaged neighborhoods to translate published preventive guidelines into easy-to-understand messages for the general population. Method: Our research team established partnerships with older aged community groups located in disadvantaged neighborhoods, determined by cross-referencing addresses with the Australian Bureau of Statistics, to translate guidelines regarding osteoporosis prevention. Results: We developed an oversized jigsaw puzzle that we used to translate recommended osteoporosis prevention guidelines. Discussion: Successful participatory partnerships between researchers, health promotion professionals, and community groups in disadvantaged neighborhoods build capacity in researchers to undertake future participatory processes; they also make the best use of expert knowledge held by specific communities.
Progressive tool condition monitoring of end milling from machined surface images
Authors: Dutta Samik , Pal Surjya K , Sen Ranjan
Published: April 2016

Indirect tool condition monitoring in end milling is inevitable to produce high-quality finished products due to the complexity of end-milling process. Among the various indirect tool condition monitoring techniques, monitoring based on image processing by analyzing the surface images of final product is gaining high importance due to its non-tactile and flexible nature. The advances in computing facilities, texture analysis techniques and learning machines make these techniques feasible for progressive tool flank wear monitoring. In this article, captured end-milled surface images are analyzed using gray level co-occurrence matrix–based and discrete wavelet transform–based texture analyses to extract features which have a good correlation with progressive tool flank wear. Contrast and second diagonal moment are extracted from gray level co-occurrence matrix and root mean square and energy are extracted from discrete wavelet decomposition of end-milled surface images as features. Finally, these four features are utilized to build support vector machine–based regression models for predicting progressive tool flank wear with 94.8% average correlation between predicted and measured tool flank wear values.
Hydrogen embrittlement characteristics of two tempered martensitic steel alloys for high-strength bolting
Authors: Brahimi SV , Sriraman KR , Yue S
Published: April 2016

Hydrogen embrittlement threshold curves were derived for two quenched and tempered steel grades, AISI 4135 and AISI 4340, at varying hardness ranging from 33 to 54 HRC. For each material, hydrogen was introduced (i) by zinc electroplating as a worst case condition for internal hydrogen embrittlement and (ii) by imposing cathodic potential of −1.2 V as a worst case condition for environmental hydrogen embrittlement. Overall, AISI 4135 exhibited lower thresholds than AISI 4340, making it the more susceptible of the two alloys. The findings demonstrate although hardness and/or strength have a first-order effect on hydrogen embrittlement susceptibility, difference in chemistry leading to differences microstructural characteristics must also be considered. Below hardness of 39 HRC, both alloys were not susceptible to internal hydrogen embrittlement, a finding that is consistent with common industry practice and fastener electroplating standards that do not mandate baking of electroplated fasteners with specified hardness below 39 HRC.
Adaptive neuron for moment of inertia and torque control based on state observer
Authors: Wang Lei , Zhang Yongde , Hao Shuanghui , Hao Minghui , Song Baoyu
Published: April 2016

In this article, a simple self-adaptive neuron based on a position state observer has been proposed to inhibit the influence of load disturbances and accomplish a self-adaptive correction of the moment of inertia. In the process of inertial correction, the error of the position state observer is gradually reduced that facilitates the simultaneous optimisation of the position observer and moment of inertia. Furthermore, it allows accurate prediction of the position value by the position state observer in the subsequent control cycle. Simulations and experiments indicate that the designed controller performs with better adaptive response and robustness compared to the controller that does not implement the proposed method, and that the position state observer estimates the position accurately, a response associated with numerous advantages for practical applications.
Kinematics analysis of a redundantly actuated 4-RUU translational parallel manipulator and its nonredundant 3-RUU counterpart
Authors: Qu Haibo , Guo Sheng , Zhang Ying
Published: April 2016

This paper presents a comparative study of the kinematics and torque distribution performance of a nonredundant 3-RUU and a redundantly actuated 4-RUU (R: revolute joint, U: universal joint) translational parallel manipulators. First, the reason for unexpected rotations is analyzed based on screw theory and a redundantly actuated 4-RUU translational parallel manipulator is presented to eliminate the unexpected rotations. Then, the degrees of freedom, inverse kinematics, Jacobian matrices, and workspace of 3-RUU and 4-RUU parallel manipulators are analyzed. Finally, a comparative study of torque distribution is performed. The results show that the redundantly actuated 4-RUU parallel manipulator can overcome the unexpected rotations and possesses an improved torque distribution, compared with the nonredundant 3-RUU parallel manipulator.
Design and development of a new large-stroke XY compliant micropositioning stage
Authors: Wan Sicong , Zhang Yulong , Xu Qingsong
Published: April 2016

This paper presents the design and development of a new flexure-based compliant XY micropositioning stage with large stroke. The parallel-kinematic XY compliant stage is designed based on the Roberts mechanisms. Pseudo-rigid-body model is developed to establish the quantitative models of the whole compliant mechanism. Finite element analysis is carried out to validate the performance of the XY stage. A prototype of the XY stage is developed for experimental investigations. Experimental results show that the stage can deliver a working range larger than 12 mm in each of the two working axes. Moreover, a feedback control using the proportional–integral–derivative control algorithm is implemented to demonstrate the positioning performance of the developed XY stage. The reported ideas can also be extended to the design and control of other micro-/nanopositioning systems.
Experimental study of passive vibration suppression using absorber with spherical ball impact damper
Authors: Chaari Riadh , Djemal Fathi , Chaari Fakher , Abbes Mohamed Slim , Haddar Mohamed
Published: April 2016

Impact dampers are efficient in many industrial applications with a wide range of frequencies. An experimental analysis of the impact damping of spherical balls is investigated to simplify the particle impact damping design and improve the vibration suppression. The objective of the study is to analyze some of the design parameters of impact damper using spherical balls. The experimental investigation consists to test the effect of the ball size for each mass level, the number of balls for each size level and different exciting force levels on vibrations of the main structure. The parametric study provided useful information to understand and optimize Particle Impact Damping design.
An analytical approach to determine motions/constraints of serial kinematic chains based on Clifford algebra
Authors: Huo Xinming , Sun Tao , Song Yimin , Qi Yang , Wang Panfeng
Published: April 2016

Determining the motions and constraints of serial kinematic chains in a concise and visual way is an inevitable step in the analysis and design of both serial and parallel mechanisms. The now most used method is the numerical approach which resorts to solving linear equations. By introducing Clifford algebra, this paper intends to propose an analytical approach to determine the unknown 6- n ( n < 6) constraints (motions) from the known n motions (constraints) of serial kinematic chains in different configurations only by drawing some auxiliary points, lines, and planes. The axes and action lines of motions and constraints are characterized by the lines that would be described by Clifford algebra. These lines can be determined analytically according to the relations among points, lines, and planes, which have been expressed by using the operation rules of Clifford algebra Cl(0, 3, 1) such as inner, outer, dual, and shuffle products. Based upon the mechanics principle that the constraint does not work on the motion, the unknown 6- n constraints (motions) of serial kinematic chains from known n motions (constraints) are determined both in an analytical algebraic form and in a visual manner. Finally, four examples are given to demonstrate how to use this approach and test its validity. The merit of this approach is beneficial to the digital analysis and design of both the serial and parallel mechanisms by means of computer and programming languages.
Strength check of a three-row roller slewing bearing based on a mixed finite element model
Authors: Li Yunfeng , Jiang Di
Published: April 2016

For the two failure modes of a three-row roller slewing bearing, ring fracture and raceway spalling, a method for checking the strength of a slewing bearing through finite element analysis is proposed. This method calculates the internal stress distribution of the bearing rings by using the mixed finite element model with both solid elements and spring elements of the slewing bearing assembly and checks the bearing structural strength by using the maximum internal stress of the bearing rings. The method also calculates the contact stress between the roller and raceways by using the entity contact model between the roller and the raceways; the obtained maximum contact stress is used to check the contact strength of the slewing bearing. The proposed mixed finite element model considers the structural deformation of the bearing rings, and the calculated results can reflect the real situation more accurately than the traditional analytical model with the hypothesis of rigid ring. The proposed method also avoids the solution problem, which has large-scale calculation and difficulty of convergence of the entity finite element model of a slewing bearing, and the calculation efficiency is improved effectively. The calculated results by mixed finite element model are consistent with the failure mode of this type of slewing bearing in engineering practice.
Effect of combined fatigue and hygrothermal loading on structural properties of E-glass/polymers
Authors: Saini Abhineet , Chhibber Rahul , Chattopadhyay A
Published: April 2016

The paper discusses the potential ingress and combined effect of moisture and temperature on pre-fatigued glass fibre-reinforced polymers standard test specimens. An experimental investigation was conducted to analyse the behaviour of glass fibre-reinforced polymers’ in environmental conditions similar to that of tropical environments. The standard pre-fatigued glass fibre-reinforced polymers specimens were subjected to varying hygrothermal conditions: three different temperatures, i.e. natural bath, 45 ℃ and 55 ℃ to study the degradation in strength and related properties. Several macro-structural and micro-structural tests were conducted to determine the damage. The effect of these conditions on characteristics such as diffusivity, weight gain, resin volume fraction, conductivity and deterioration of ultimate tensile strength was determined. The maximum reduction in strength is found to be approximately 39% for the specimen exposed to 55 ℃ water bath for 60 days. This study shall be helpful in estimating the characteristics of glass fibre-reinforced polymers composites subjected to cyclic fatigue loads in the tropical conditions.
Research on wheel hollow wear and dynamic performance of freight radial bogies
Authors: Li Hengli , Li Fu , Huang Yunhua
Published: April 2016

The wheel wear properties of heavy haul bogies running on the Da-Qin railway line were measured. The hollow and asymmetric wear are indicated. The wheel/rail contact geometry relationship was calculated on the basis of the measured wheel profiles. The dynamic simulation model using SIMPACK software for C80BF Gondola with ZK7 radial bogie and C80B gondola with ZK6 cross brace bogie was established. The hollow depth effect on wheelset attack angle and lateral force was quantified. According to the actual conditions of Da-Qin railway line, the hollow wear was predicted using a numerical method. Based on these results, the hollow wear maintenance standard was recommended. Finally, a field test for asymmetric hollow wear was described.
Structural reliability assessment based on low-discrepancy adaptive importance sampling and artificial neural network
Authors: Zhao Hailong , Yue Zhufeng , Liu Yongshou , Liu Wei , Gao Zongzhan
Published: April 2016

In the field of structural reliability, the estimation of failure probability often requires large numbers of time-consuming performance function calls. It is a great challenge to keep the number of function calls to a minimum extent. The aim of this paper is to propose an approach to assess the structural reliability in an efficient way. The proposed method could be viewed as a hybrid reliability method which combines the advantages of adaptive importance sampling, low-discrepancy sampling and artificial neural network. In the proposed method, artificial neural network is introduced to alleviate the computational burden of deterministic and boring engineering analysis, and its introduction guarantees the computational efficiency of the proposed method. While the Markov chain process is adopted to generate the experimental samples which are used to construct the artificial neural network, the introduction of Markov chain process guarantees the adaptivity of the proposed method and makes the proposed method applicable for various reliability problems. The proposed method is shown to be very efficient as the estimated failure probability is very accurate and only a small number of calls to the actual performance function are needed. The effectiveness and engineering applicability of the proposed method are demonstrated by several test examples.