bluuebunny/crossref_metadata_2025 huggingface dataset:
An improved energy envelope stochastic averaging method and its application to a nonlinear oscillator
Authors: Zhao Yaping
Published: March 2015

An improved stochastic averaging method of the energy envelope is proposed, whose application sphere is extensive and whose implementation is convenient. An oscillating system with both nonlinear damping and stiffness is taken into account. Its averaged Fokker-Planck-Kolmogorov (FPK) equation in respect of the transition probability density function of the energy envelope is deduced by virtue of the method mentioned above. Under the initial and boundary conditions, the joint probability density function as to the displacement and velocity of the system is worked out in closed form after solving the averaged FPK equation by right of a technique based on the integral transformation. With the aid of the special functions, the transient solutions of the probabilistic characteristics of the system response are further derived analytically, including the probability density functions and the mean square values. A simple approach to generate the ideal white noise is drastically ameliorated in order to produce the stationary wide-band stochastic external excitation for the Monte Carlo simulating investigation of the nonlinear system. Both the theoretical solution and the numerical solution of the probabilistic properties of the system response are obtained, which are extremely coincident with each other. The numerical simulation and the theoretical computation all show that the time factor has a certain influence on the probability characteristics of the response. For example, the probabilistic distribution of the displacement tends to be scattered and the mean square displacement trends toward its steady-state value as time goes by. Of course the transient process to reach the steady-state value will obviously be shorter if the damping of the system is greater.
Tuned pendulum as nonlinear energy sink for broad energy range
Authors: Farid Maor , Gendelman Oleg V
Published: March 2015

Nonlinear energy sinks (NES) are widely studied as a possible engineering solution for mitigation of steady-state, impulsive and transient broadband excitations. Current work is devoted to the applicability of common pendulum as the NES for mitigation of impulsive excitations. It turns out that the pendulum NES can overcome one of the main shortcomings of more traditional NES designs, since it is able to mitigate excitation of a primary system in a relatively wide range of initial energies. This is because the pendulum can be captured into a resonance with primary oscillator both for rotational and oscillatory responses. If parameters are chosen properly, for small energies the pendulum responds almost as a common tuned mass damper. However, at higher energies, the pendulum acts as rotational NES. Thus, relatively broad diapason of initial energies can be covered. This paper presents numeric evidence for the efficiency of this design of the NES and discusses its optimal tuning. Another important finding is that the NES’s efficiency exhibits rather broad deviations for different realizations of the initial conditions with the same energy. We present a theoretical analysis of the damped targeted energy transfer into the pendulum NES from the primary mass with an account of corrections caused by the effect of gravity.
¿Eres Amigo o Enemigo? Contextual Determinants of Latinos’ Perceived Competition with African-Americans
Authors: Carey Tony E. , Martinez-Ebers Valerie , Matsubayashi Tetsuya , Paolino Philip
Published: March 2015

Prior research has examined how racial and socioeconomic environments influence the racial attitudes of Whites and Blacks. We extend this line of research to explore how local context influences Latinos’ perceived competition with African-Americans. We use the 2006 Latino National Survey and a newly appended contextual data set. We find that having more Black neighbors heightens Latinos’ perceived competition with Blacks, but only when Latinos are economically vulnerable. The presence of African-Americans within Latinos’ neighborhoods is a necessary but insufficient condition for increasing their perceived competition with Blacks; Latinos’ perceived threat is shaped by the combined effect of the neighborhood racial composition and their group’s economic status.
Association Between Altitude and Regional Variation of ADHD in Youth
Authors: Huber Rebekah S. , Kim Tae-Suk , Kim Namkug , Kuykendall M. Danielle , Sherwood Samantha N. , Renshaw Perry F. , Kondo Douglas G.
Published: March 2015

Objective: The purpose of this study was to evaluate the effect of altitude on rates of ADHD. As decreased dopamine (DA) activity has been reported with ADHD and hypoxia has shown to be associated with increased DA, we hypothesized that states at higher altitudes would have lower rates of ADHD. Method: State estimates from the 2007 National Survey of Children’s Health (NSCH) report and 2010 National Survey of Children with Special Health Care Needs (NS-CSHCN) report were used to extract the percentages of youth ages 4 to 17 diagnosed with ADHD. Results: Both the datasets independently revealed that the prevalence of ADHD decreases with increasing altitude ( R2 = .38, p < .001; R2 = .31, p < .001), respectively. This study controlled for potential confounds (e.g., low birth weight, ethnicity, and household size). Conclusion: These findings suggest a need for further investigation into the extent by which altitude may serve as a protective factor for ADHD.
The Collective Impact Model and Its Potential for Health Promotion
Authors: Flood Johnna , Minkler Meredith , Hennessey Lavery Susana , Estrada Jessica , Falbe Jennifer
Published: March 2015

As resources for health promotion become more constricted, it is increasingly important to collaborate across sectors, including the private sector. Although many excellent models for cross-sector collaboration have shown promise in the health field, collective impact (CI), an emerging model for creating larger scale change, has yet to receive much study. Complementing earlier collaboration approaches, CI has five core tenets: a shared agenda, shared measurement systems, mutually reinforcing activities, continuous communication, and a central infrastructure. In this article, we describe the CI model and its key dimensions and constructs. We briefly compare CI to community coalition action theory and discuss our use of the latter to provide needed detail as we apply CI in a critical case study analysis of the Tenderloin Healthy Corner Store Coalition in San Francisco, California. Using Yin’s multimethod approach, we illustrate how CI strategies, augmented by the community coalition action theory, are being used, and with what successes or challenges, to help affect community- and policy-level change to reduce tobacco and alcohol advertising and sales, while improving healthy, affordable, and sustainable food access. We discuss the strengths and weaknesses of CI as a framework for health promotion, as well as the benefits, challenges, and initial outcomes of the healthy retail project and its opportunities for scale-up. Implications for health promotion practice and research also are discussed.
Effects of Air Pollution-Related Heavy Metals on the Viability and Inflammatory Responses of Human Airway Epithelial Cells
Authors: Honda Akiko , Tsuji Kenshi , Matsuda Yugo , Hayashi Tomohiro , Fukushima Wataru , Sawahara Takahiro , Kudo Hitomi , Murayama Rumiko , Takano Hirohisa
Published: March 2015

Various metals produced from human activity are ubiquitously detected in ambient air. The metals may lead to induction and/or exacerbation of respiratory diseases, but the significant metals and factors contributing to such diseases have not been identified. To compare the effects of each metal and different oxidation states of metals on human airway, we examined the viability and production of interleukin (IL)-6 and IL-8 using BEAS-2B cell line, derived from human airway epithelial cells. Airway epithelial cells were exposed to Mn2+, V4+, V5+, Cr3+, Cr6+, Zn2+, Ni2+, and Pb2+ at a concentration of 0.5, 5, 50, or 500 μmol/L for 24 hours. Mn and V decreased the cell viability in a concentration-dependent manner, and V5+ tended to have a greater effect than V4+. The Cr decreased the cell viability, and (Cr+6) at concentrations of 50 and 500 μmol/L was more toxic than (Cr+3). Zn at a concentration of 500 μmol/L greatly decreased the cell viability, whereas Ni at the same concentration increased it. Pb produced fewer changes. Mn and Ni at a concentration of 500 μmol/L induced the significant production of IL-6 and IL-8. However, most of the metals including (V+4, V+5), (Cr+3, Cr+6), Zn, and Pb inhibited the production of both IL-6 and IL-8. The present results indicate that various heavy metals have different effects on toxicity and the proinflammatory responses of airway epithelial cells, and those influences also depend on the oxidation states of the metals.
Scaling soft matter physics to thousands of graphics processing units in parallel
Authors: Gray Alan , Hart Alistair , Henrich Oliver , Stratford Kevin
Published: March 2015

We describe a multi-graphics processing unit (GPU) implementation of the Ludwig application, which specialises in simulating a variety of complex fluids via lattice Boltzmann fluid dynamics coupled to additional physics describing complex fluid constituents. We describe our methodology in augmenting the original central processing unit (CPU) version with GPU functionality in a maintainable fashion. We present several optimisations that maximise performance on the GPU architecture through tuning for the GPU memory hierarchy. We describe how we implement particles within the fluid in such a way to avoid a major diversion of the CPU and GPU codebases, whilst minimising data transfer at each time step. We detail our halo-exchange communication phase for the code, which exploits overlapping to allow efficient parallel scaling to many GPUs. We present results showing that the application demonstrates excellent scaling to at least 8192 GPUs in parallel, the largest system tested at the time of writing. The GPU version (on NVIDIA K20X GPUs) is around 3.5–5 times faster that the CPU version (on fully utilised AMD Opteron 6274 16-core CPUs), comparing equal numbers of CPUs and GPUs.
Data decomposition in Monte Carlo neutron transport simulations using global view arrays
Authors: Dun Nan , Fujita Hajime , Tramm John R. , Chien Andrew A. , Siegel Andrew R.
Published: March 2015

Accommodating large tally data can be a challenging problem for Monte Carlo neutron transport simulations. Current approaches include either simple data replication, or are based on application-controlled decomposition such as domain partitioning or client/server models, which are limited by either memory cost or performance loss. We propose and analyze an alternative solution based on global view arrays. By using global view arrays, tallies are naturally partitioned into small globally addressable blocks that fit in the limited on-node memory of compute nodes, achieving both highly scalable memory and performance efficiency. This approach also greatly simplifies the programmability compared with application-controlled approaches. Our implementation is based on integrating a global view library built on MPI one-sided communication, global view resilience (GVR), into the OpenMC Monte Carlo transport code. The remote memory access (RMA)-based global view array implementation is able to achieve 85% efficiency at 16,384 processes compared with 1,000 processes with 2.39 TB mesh tally across 1,366 nodes on a Cray XC30 supercomputer. Our results improve scalability significantly compared with the tally server approach and are better than any other published results, indicating that global view array is a promising alternative to enable full-core light water reactor analysis on current and future computer systems.
An asymptotic meshless method for sandwich functionally graded circular hollow cylinders with various boundary conditions
Authors: Wu Chih-Ping , Jiang Ruei-Yong
Published: March 2015

An asymptotic meshless method using the differential reproducing kernel interpolation and perturbation method is formulated for the three-dimensional bending analysis of sandwich functionally graded circular hollow cylinders and laminated composite ones with clamped and simply-supported edge conditions, in which the effective material properties of the functionally graded layer are evaluated using the Mori–Tanaka scheme. In the formulation, we perform the mathematical processes of nondimensionalization, asymptotic expansion and successive integration to obtain recurrent sets of governing equations for various order problems. Classical shell theory is derived as a first-order approximation of the three-dimensional theory of elasticity, and the governing equations for higher order problems retain the same differential operators as those of classical shell theory, although with different nonhomogeneous terms. Expanding the primary field variables of each order as the Fourier series functions in the circumferential direction, and interpolating these in the axial direction using the differential reproducing kernel interpolation, we can obtain the leading-order solutions of this analysis, and the higher order modifications can then be determined in a systematic manner. Some benchmark solutions for the bending analysis of sandwich functionally graded circular hollow cylinders and laminated composite ones subjected to mechanical loads are given to demonstrate the performance of the asymptotic meshless method.
Treatment effect with anti-RAGE F(ab′)2 antibody improves hind limb angiogenesis and blood flow in Type 1 diabetic mice with left femoral artery ligation
Authors: Tekabe Yared , Anthony Tamykah , Li Qing , Ray Rashmi , Rai Vivek , Zhang Geping , Schmidt Ann Marie , Johnson Lynne L
Published: March 2015

We investigated treatment with a receptor for advanced glycation endproduct (RAGE) blocking antibody on angiogenic response to hind limb ischemia in diabetic mice. Streptozotocin treated C57BL/6 mice received either murine monoclonal anti-RAGE F(ab′)2 intraperitoneally ( n=10) or saline ( n=9) for 9 weeks. Diabetic plus 10 non-diabetic C57BL/6 mice underwent left femoral artery ligation and 5 days later angiogenesis imaging with 99mTc-Arg–Gly–Asp (RGD) nanoSPECT/CT. Twenty-four days later, hind limb blood flow was measured with ultrasound, the mice were euthanized, and tissue was taken for immunohistochemistry. The angiogenic imaging signal in ischemic limbs was higher in RAGE-ab treated versus saline treated mice at day 5 (3.1±1.4 vs 1.68±0.35, p=0.02) and blood flow was higher at day 24 (1.49±0.5 vs 0.61±0.39, p=0.04). Immunohistochemistry of ischemic muscles showed greater capillary density in the RAGE-ab treated group versus the vehicle-treated group ( p<0.001) (NS from non-diabetic mice). In conclusion, treatment with anti-RAGE F(ab′)2 in diabetic mice improves neovascularization in the ischemic leg.
A critical review of adolescent mindfulness-based programmes
Authors: Tan Lucy BG
Published: March 2015

Objectives:

Previous research has demonstrated that mindfulness-based programmes improve psychological functioning in a myriad of adult domains. These include health care, marketing and sports industries. The efficacy of mindfulness-based programmes in the adult population is well established. Indeed, compared to adult empirical literature, mindfulness programmes for adolescents are relatively developmental and less articulated until now. It may be argued that mindfulness-based programmes could and should begin early and be applicable to young people at a time that is critical in their development. Hence, this article analyses the characteristics, objectives and outcomes of mindfulness interventions for adolescents, focusing on the mindfulness programme adjustments and adaptations made to the content for this target group.

Method:

A critique of the literature that included published articles of mindfulness-based interventions (both clinical and universal programmes) for adolescents were sourced and reviewed. Conference papers and unpublished dissertations were excluded.

Results:

The review indicated that a majority of these were longitudinal and feasibility studies, with only one clinical randomised controlled trial study.

Conclusion:

Preliminary evidence for the use of mindfulness-based with adolescents continues to be nascent, with many of the studies using inappropriate or no mindfulness process measures at all. In addition, a majority of the studies did not provide specific details of the mindfulness programmes for adolescents, nor discuss what modifications were undertaken – all of which makes comparison difficult. However, with the availability of recent and age-appropriate mindfulness measures for adolescents, more rigorous and robust research looks promising.
Horses for courses? A qualitative exploration of goals formulated in mental health settings by young people, parents, and clinicians
Authors: Jacob Jenna , Edbrooke-Childs Julian , Holley Simone , Law Duncan , Wolpert Miranda
Published: March 2015

Introduction:

This research sought to explore and categorise goals set by children and young people, parents/caregivers and jointly by a combination of children/young people, parents/caregivers and/or clinicians within mental health settings across the United Kingdom.

Method:

Using a dataset of 441 goals formed at the outset of 180 treatment episodes (2007–2010) from UK child mental health services using the Goal-Based Outcomes tool, a grounded theory approach was taken, which built on previous research into child-rated goals to develop frameworks for parent and joint goal data which were then compared with the child goal data.

Results:

A total of 19 subthemes and four overarching themes were identified for parent goals. A total of 19 subthemes in five overarching themes were identified for joint goals. These were compared with 25 subthemes and three overarching themes for child goals. A comparison of subthemes between parent, child and joint goals demonstrated many consistencies, but also differences. Most commonly rated goals from children focused on coping with specific difficulties, personal growth and independence. Parent goals focused mainly on managing specific difficulties, parent-specific goals and improving self or life. Jointly negotiated goals focused on parent-specific goals, self-confidence and understanding, hopes for the future and managing specific problems.

Conclusion:

The results suggest that goals may capture areas not captured by other normed outcome measures. In particular, goals may capture higher order, underlying factors, such as confidence, resilience, coping, and parenting factors that may not be explored by other measures. The differences across perspectives also link to existing literature suggesting a different focus on treatment based on perspectives and highlights the potential importance when jointly agreeing goals of ensuring the voice of the child/young person is heard and included in goal setting.
Cuéntame cómo pasó/Tell me how it was: Narratives of memory and television drama in contemporary Spain
Authors: Loxham Abigail
Published: March 2015

This article examines the role of audio-visual media in the negotiation and representation of cultural memory in contemporary Spain. The political silencing of one version of history during the Francoist dictatorship and the Transition to democracy sees the country battling with over 70 years of ideological manipulation of history and silencing of personal recollections. This article looks at the way in which the media are playing a significant role in sustaining, renegotiating and remediating memory in the light of the silence that precedes it. It argues that testimony, television and other popular media forms deserve sustained critical attention with regard to the creation of memory in Spain and should not be dismissed as simply vehicles for nostalgia or as spurious recreation of a brutal past but that, in line with work on the dynamics of cultural memory, should be seriously considered as part of attempts to redress the legacy of silence and mobilise a discourse of memory.
Power, politics and the street-level bureaucrat in Indigenous Australian health
Authors: O’Sullivan Dominic
Published: March 2015

Street-level professional workers’ influence over Indigenous health policy implementation is an important variable in a contested policy environment distinguished by an Indigenous median age of death approximately 20 years less than for non-Indigenous citizens. Street-level workers are guided by personal political values in the ways that they prioritise their work and make decisions about the care that will be available to particular patients. The possibility that street-level workers may make decisions with reference to stereotypical or prejudiced judgements about Indigenous peoples makes their bureaucratic discretion a point of particular significance. Alternatively, their capacity to work on the assumption that they have the professional agency and a moral duty to make a substantive contribution to improving Indigenous health outcomes positions their work in the context of social justice. The street-level worker is, then, drawn into the politics of public policy and policy activism, where ideology sits alongside professional knowledge and skills as determinants of Indigenous health outcomes, and where public policy’s intellectual and practical inconsistencies simultaneously constrain opportunities for bureaucratic discretion in some respects and provide new opportunities in others, such that the street-level worker is a central participant in the politics of Indigenous health.
‘Everyone knew everyone’s business’: Being a parent with housing issues in rural areas
Authors: Reupert Andrea , Jones Rebecca , Sutton Keith , Maybery Darryl
Published: March 2015

This research explored the intersection between participants’ parenting role and housing difficulties, in rural communities. Thirteen parents were recruited from drug and alcohol and mental health agencies in rural Australia. Transcripts were analysed using content analysis, along with inter-rater reliability. The quandary of gaining access to their children while living in inadequate housing was indicated. Participants also described the ‘spiral’ nature of problems, highlighting the interrelated nature of mental illness, substance use, housing difficulties and losing access to children. The impacts of housing problems on parenting roles and children were described as well as those supports considered to be useful in obtaining appropriate housing. Living in rural areas where ‘everyone knew everyone’ made it difficult for some to obtain housing. The need to address housing, parenting, mental illness and substance abuse as interrelated, rather than as singular issues is highlighted.
Defining and measuring youth digital citizenship
Authors: Jones Lisa M , Mitchell Kimberly J
Published: March 2015

There is an increasing interest in improving youth digital citizenship through education. However, the term ‘digital citizenship’ currently covers a broad range of goals. To improve education, the current article argues for a narrower focus on (1) respectful behavior online and (2) online civic engagement. Using this definition, a digital citizenship scale was developed and assessed with a sample of 979 youth, aged 11–17 years, and confirmatory factor analyses (CFAs) supported measurement of both constructs: online respect (7 items, Cronbach’s α = .92) and online civic engagement (4 items, Cronbach’s α = .70). Online respect scores decreased with youth age, and scores on both subscales were higher among girls than boys. Both online respect and civic engagement were negatively related to online harassment perpetration and positively related to helpful bystander behaviors, after controlling for other variables. Implications of the study findings for developing and evaluating digital citizenship educational programs are discussed.
An experimental investigation and optimization of friction stir welding process for AA6082 T6 (cryogenic treated and untreated) using an integrated approach of Taguchi, grey relational analysis and entropy method
Authors: Jangra Kamal K , Sharma Neeraj , Khanna Rajesh , Matta Deepak
Published: March 2015

Friction stir welding is a solid state welding in which two metal parts are joined without melting with the help of frictional heat generated between the work material and non-consumable tool. Because of the poor microstructure, cracks, porosity and residual stresses in fusion welding of aircraft aluminium alloys, friction stir welding is highly attractive for joints in aircraft structures. In the present work, using Taguchi’s design of experiment method, combined effect of process parameters namely tool rotation speed, welding speed (or traverse speed of tool), tool pin profile and tool shoulder diameter have been investigated for the ultimate tensile strength and percentage elongation of friction stir welded joints of AA6082 alloy. Two similar sets of experiments were performed to prepare the friction stir welded joints; first samples of AA 6082-T6 (solution heat treated and artificially aged) were friction stir welded and second cryogenic treated AA6082 alloy were friction stir welded . A comparison in the optimal conditions of two sets of experiments has also been presented. In tempered aluminium alloy, three process parameters namely tool rotation, weld speed and tool shoulder diameter are significantly affecting ultimate tensile strength, while all four parameters are significant for percentage elongation. The influence of cryogenic treatment has also been noticed on two response characteristics. An integrated approach of Taguchi method, grey relational analysis and entropy measurement method have been utilized to obtain an optimal single setting of process parameters for two response characteristics. For the friction stir welded joint of AA6082-T6 (without cryogenic treatment), a single optimal setting of process parameters was obtained corresponding to tool rotation: 1200 r/min, weld speed: 35 mm/min, tool pin profile, threaded cylindrical and tool shoulder diameter: 16 mm. Similarly, the single optimal setting for cryogenic treated aluminium alloy (AA6082) was obtained corresponding to tool rotation: 1200 r/.min, weld speed: 35 mm/min, tool pin profile, cylindrical and tool shoulder diameter: 14 mm.
Optimal material tailoring of 2D heterogeneous cylinder for a prescribed temperature field in transient heat conduction
Authors: Asgari Masoud
Published: March 2015

In this paper, optimization of volume fraction distribution in a finite length thick hollow cylinder made of heterogeneous material is considered. The cylinder has two-directional functionally graded constituent and subjected to transient thermal loading. Two-dimensional heat conduction in the cylinder is considered and variation of temperature with time as well as temperature distribution through the cylinder is investigated. A graded finite element method combined with direct time integration method is used to model the structure and solve time-dependent equations. Volume fractions of constituent materials on a finite number of design points are taken as design variables and the volume fractions at any arbitrary point in the cylinder are obtained via cubic spline interpolation functions. The objective is to minimize the difference between the actual distribution of the temperature through the structure and a desired target distribution after a prescribed time while the total mass of the structure is also minimized. Multi-objective Genetic Algorithm jointed with interior penalty-function method for implementing constraints is effectively employed to find the global solution of the optimization problem. Obtained results indicate that by using the uniform distribution of temperature and minimum mass as objective functions, considerably more effective usage of materials can be achieved compared with the common power law volume fraction distribution. The proposed methodology provides a framework for designing functionally graded structures with optimum material tailoring for a prescribed field variable problem.
Journey’s end? From residual service to newer forms of pathology, risk aversion and abandonment in social work with older people
Authors: Carey Malcolm
Published: March 2015

This article details how social work with older people is disappearing whilst also being supplanted by seemingly more cost-effective forms of intervention in the UK. This has included the use of higher numbers of unqualified staff in roles once completed by qualified social workers, alongside highly rationed interventions that utilise fewer staff or associate welfare professionals, including those drawn from health care.

Findings

Such reforms represent important changes embedded within neo-liberal inspired professional discursive practices. These include the biomedicalisation of ageing and associate narrow gaze interpretations of social care needs that privilege pathology and risk. For social work there has also been an ongoing retreat from older adults within communities: from care-managed and personalised support to the extension of ‘risk averse’ safeguarding and promotion of personal autonomy for users and informal care. Rather than represent a break with the past, such socially constructed and politically motivated reforms remain part of longer held societal and ideological trends. Importantly, these include assumptions that older users remain a peripheral concern in contrast to other social groups or needs.

Applications

The article concludes that the social work profession needs to articulate its distinct role with regard to its capability to provide substantive support to an ageing population, alongside its capacity to look beyond a narrow and unsustainable focus on rationing or the endorsement of self-support, treating illness and controlling risk.
Diverging dividends, diverging futures: Nativity, citizenship status, legal status, and the non-housing asset accumulation of Latinos
Authors: McConnell Eileen Díaz
Published: March 2015

Holding assets other than a primary residence are important for surviving economic downturns and providing opportunities for wealth creation. However, prior research shows that US Latinos are unlikely to own assets aside from a home; when they do, they have relatively little non-housing wealth. This study uses Los Angeles Family and Neighborhood Survey data to examine variation in ownership of bank accounts, retirement accounts, and the value of non-housing assets among four Latino groups: the US-born, naturalized citizens, authorized non-citizens, and unauthorized non-citizens. All four groups display relatively low levels of asset ownership and value. However, multivariate results reveal that only unauthorized immigrants are persistently disadvantaged in non-asset ownership and value, net of socio-demographic and migration-related characteristics. These results have implications for prominent theoretical perspectives of immigrant mobility and contribute to scholarship identifying legal status as a significant form of stratification in the United States.
Intra-Latina/Latino encounters: Salvadoran and Mexican struggles and Salvadoran–Mexican subjectivities in Los Angeles
Authors: Osuna Steven
Published: March 2015

In the last 30 years, the mass transnational migration of Salvadorans and Mexicans to the U.S. from their countries due to changes in the world capitalist system, and its specific effects on their homelands, has made Los Angeles the most Mexican and Salvadoran-populated city in the United States. Within the everyday struggles of the working class in Los Angeles, an internal antagonism between these two Latina/Latino communities has developed that has divided them yet, dialectically, a sense of solidarity between them vis-à-vis the dominant racialized regime of the U.S. has also emerged. This paper investigates this dialectical interplay of tension and solidarity between Salvadoran and Mexican communities in Los Angeles through qualitative interviews with 20 young adults who are children of mixed Salvadoran–Mexican migrant families. This paper will contextualize their families’ experiences within a larger theoretical, analytical, and historical framework of the global capitalist system and recent transnational processes, including neoliberalism, migration, and the racialization of Latina/Latinos in the U.S. The exploration of the participants’ families and their relationships to a series of structural and cultural factors that ground both communities, such as racialized labor market competition, migration, and national belonging, may assist in explaining this dialectical interplay of tension and solidarity.
The urban question and identity formation: The case of second-generation Mexican males in Los Angeles
Authors: Rendón Maria G.
Published: March 2015

The concept of downward assimilation warns that second-generation Mexican-origin youth in the inner city are at great risk of developing a “reactive” identity and acculturating into chronic poverty through socialization with third-plus generation racial minorities. I test this proposition by examining and comparing ethnic boundary formation for 42 second-generation Latinos from two disadvantaged neighborhoods in Los Angeles: one predominantly Mexican immigrant and the other with a sizeable representation of a racial minority group, African Americans. I find that urban conditions influence ethnic identity but not as proposed by downward assimilation. Social isolation from white Americans in urban neighborhoods means that the Mexican second-generation rarely embraces a “reactive” identity but instead adopts and expresses various and competing ethnic labels, holding strongly to an immigrant identity. Latino young men experience the Black/Latino urban neighborhood as a contested space and urban violence as racially charged. These urban conditions strain race relations and “brighten” rather than “blur” ethnic and racial boundaries and identities between the Mexican second-generation and Blacks. This study suggests that to understand identity formation and acculturation processes in central cities, it is essential to consider how structural conditions impact social interaction in urban space.
Latina/o identities, the racialization of work, and the global reserve army of labor: Becoming Latino in Postville, Iowa
Authors: Olivos Edward M. , Sandoval Gerardo F.
Published: March 2015

This article argues that the experiences and group formation of the Latino population in the United States can best be understood by employing a framework which examines global economic and political forces—forces which draw upon Latin America’s global reserve army of labor to meet and exceed U.S. national labor demands in order to increase capital accumulation. While cautioning against viewing Latinos as a homogenous “culture,” the authors’ framework acknowledges shared racialized historical experiences and examines how a large segment of the Latino population fits into distinct spheres of the U.S. labor and economic system. The authors ground their theoretical framing using a case study of Guatemalan immigrants in a small U.S. Midwestern town. The authors conclude that Latinos in U.S. labor markets are used to perpetuate power dynamics, disrupt worker consciousness, and racialize Latinos around jobs.
Arizona: National Tea Party Headquarters—A comparative review of three books
Authors: Gonzalez Gilbert G.
Published: March 2015

This essay reviews three books that examine Arizona’s political actions contextualized within an ongoing national debate over the how to deal with the mass migration, particularly undocumented migration, from Mexico, Central America and other regions of Latin America. The book titles tell much of Arizona’s political culture and actions propelled by the measures: Biggers (2012) State out of the Union: Arizona and the Final Showdown Over the American Dream; Magana and Lee eds. (2013) Latino Politics and Arizona’s Immigration Law SB 1970; and Santa Ana and Gonzalez de Bustamante eds. (2012) Alto Arizona! Veto SB 1070: Arizona Firestorm. Global Immigration Realities, National Media and Provincial Politics.
Open-book, open-web online examinations: Developing examination practices to support university students’ learning and self-efficacy
Authors: Myyry Liisa , Joutsenvirta Taina
Published: March 2015

The aim of this study was to investigate university students’ experiences of open-book, open-web online examinations compared to traditional class examinations concerning preparing, responding, and learning. The data (N = 110) were collected by an online survey from the university students who took an online examination. The students used approximately the same time to study for an online examination as for faculty examination, but over half of them reported using more time for responding and learning more from an online examination compared to a faculty examination. The study supports the earlier findings that assessment methods are essential for students’ learning experiences and that self-efficacy beliefs are essential in positive learning experiences. It also indicates that self-efficacy is affected differently for different students by the online context and that the individual differences in experiencing the learning environment should be taken into account in assessment procedures.
Inflammatory Response and Renal Function Following Endovascular Repair of the Descending Thoracic Aorta
Authors: Moulakakis Konstantinos G. , Sfyroeras George S. , Papapetrou Anastasios , Antonopoulos Constantine N. , Mantas George , Kakisis John , Alepaki Maria , Mylonas Spyridon N. , Karakitsos Petros , Liapis Christos D.
Published: March 2015

Purpose: To evaluate inflammatory response and renal function after thoracic endovascular aortic repair (TEVAR) of lesions in the descending thoracic aorta. Methods: Thirty-two consecutive patients treated with TEVAR from January 2010 to August 2013 were enrolled in this prospective study. Two were excluded owing to dissecting thoracic aortic aneurysm (TAA) extending into the renal arteries with renal failure in one and a saccular TAA in which a multilayer flow-modulating stent was implanted in the other. This left 30 patients (28 men; mean age 68.8±5.9 years) with 28 TAAs, an aortic dissection, and an aortic ulcer for the analysis. Temperature and serum levels of white blood cells (WBCs), C-reactive protein (CRP), interleukin-10 (IL-10), IL-6, IL-8, tumor necrosis factor-alpha (TNF-α), creatinine, urea, and cystatin C were measured preoperatively and at 24 and 48 hours postoperatively. Results: Statistically significant increases in temperature and serum levels of WBCs, CRP, IL-10, and IL-6 were observed 24 and 48 hours postoperatively compared to baseline (all p<0.05). The number of endografts and the coverage of the celiac or subclavian artery did not affect the magnitude of the inflammatory response. No significant differences were observed concerning serum levels of IL-8, TNF-α, creatinine, or cystatin C from baseline to 24 or 48 hours postoperatively. Conclusion: Endograft implantation in the thoracic aorta may propagate an inflammatory response during the early postoperative period. No clinical adverse events related to the increased inflammatory response were observed. Renal function does not seem to be deteriorated after TEVAR in the descending thoracic aorta.
Feasibility and Safety of Renal and Visceral Target Vessel Cannulation Using Robotically Steerable Catheters During Complex Endovascular Aortic Procedures
Authors: Cochennec Frédéric , Kobeiter Hicham , Gohel Manj , Marzelle Jean , Desgranges Pascal , Allaire Eric , Becquemin Jean Pierre
Published: March 2015

Purpose: To evaluate the safety and success of target vessel cannulation in the visceral aortic segment using the Magellan robotic catheter system (RCS) during complex endovascular aortic procedures. Methods: Robotic navigation was attempted for access to 37 target vessels in 15 patients (14 men; mean age 75±10 years) during 16 fenestrated and/or branched stent-grafting procedures and 1 endovascular repair requiring the chimney technique. For each target vessel, robotic navigation was attempted for a maximum of 15 minutes; if cannulation was unsuccessful in that time, manual catheters were employed. Safety was evaluated by recording intraoperative adverse events, intraoperative complications related to robotic navigation, and postoperative complications. Technical success of robotic cannulation, wire cannulation times, and times for inserting the leader over the wire in the target vessels were recorded to assess RCS performance. Results: Successful robotic cannulation was achieved for 30 (81%) of the 37 target vessels, with a median wire cannulation time of 263 seconds (range 40–780) and a median 15 seconds (range 5–450) for inserting the leader over the wire. No intraoperative complications related to robotic navigation were observed. Seven of 27 arteries accessed via 7 fenestrations could not be cannulated within 15 minute s; all were cannulated successfully using conventional catheters (mean cannulation time 31±7 minutes). All 10 target vessels accessed via branches and chimney stents were successfully cannulated with the RCS. Conclusion: Cannulation of target vessels with the RCS during complex endovascular aortic procedures is feasible and safe. The robotic system was particularly effective for branched and chimney stents.
Active Proximal Sealing in the Endovascular Repair of Abdominal Aortic Aneurysms
Authors: Melas Nikolaos , Stavridis Kyriakos , Saratzis Athanasios , Lazarides John , Gitas Christos , Saratzis Nikolaos
Published: March 2015

Purpose: To investigate the performance of a new device that uses the STRATA polytetrafluoroethylene graft material and a mechanism that provides active proximal sealing in order to prevent type Ia endoleak during endovascular aneurysm repair (EVAR). Methods: Between April 2013 and July 2014, 21 consecutive patients (all men; median age 71 years, range 60–84 years) with abdominal aortic aneurysm (median diameter 5.9 cm, range 4.9–7.8 cm) and suitable anatomy were offered elective EVAR using the AFX endograft. These patients had an irregular, conical, tapered, or bulging proximal neck, for which this specific device was considered appropriate. Aneurysm exclusion and incidence of type Ia endoleak were the primary outcomes; secondary outcomes included mortality, morbidity, migration, and other graft-related complications. Results: Primary technical success was 90%; 2 intraoperative type Ia endoleaks due to low endograft deployment were treated with additional proximal cuffs. During a median follow-up of 10 months (range 2–15 months), no type I endoleak was observed. One type II endoleak was encountered, with no associated sac enlargement. There was no stent-graft migration or any other device-related complication. One patient had a nonfatal myocardial infarction and another developed renal failure requiring transient dialysis. No deaths occurred. Conclusion: In this early experience, this newly available device appears to be safe and efficient in providing seal along irregularly shaped necks over the short term.
Midterm Outcome of EndoAnchors for the Prevention of Endoleak and Stent-Graft Migration in Patients With Challenging Proximal Aortic Neck Anatomy
Authors: Jordan William D. , de Vries Jean-Paul P. M. , Ouriel Kenneth , Mehta Manish , Varnagy David , Moore William M. , Arko Frank R. , Joye James , Henretta John
Published: March 2015

Purpose: To explore the use of EndoAnchors as an adjunct to endovascular abdominal aortic aneurysm repair for prevention of proximal neck complications in patients with challenging neck anatomy. Methods: Over a 28-month period, 208 patients (159 men; mean age 72±8 years) were enrolled in the ANCHOR prospective, multicenter registry ( ClinicalTrials.gov; identifier NCT01534819) for prophylaxis against proximal neck complications. Patients were eligible when, in the opinion of the investigators, they were at increased risk for type Ia endoleak or migration owing to a hostile neck (length <10 mm, diameter >28 mm, angulation >60°, mural thrombus or calcium >2 mm in thickness or >180° in circumference, or conical shape). Overall, 123/157 (78.3%) patients met the criteria for a hostile neck according to core laboratory assessment of 157 adequate preoperative computed tomographic (CT) images. Results: Implantation of EndoAnchors was technically successful in 204/208 (98.1%) patients. The frequency of fracture was 0.3% (3/1118); there were no clinical sequelae associated with the fractures. Over the mean 14-month follow-up, 95.2% of patients were alive, and no deaths were attributable to EndoAnchors. There were no ruptures, migrations, or open surgical conversions. Aneurysm-related reinterventions were performed in 8 (3.8%) patients. Among 130 patients with postprocedure contrast CT studies, core laboratory analysis identified 2 (1.5%) patients with type Ia endoleaks. Aneurysm sac diameter decreased >5 mm in 42.9% of patients with CT scans at or beyond 1 year; 1.6% of patients developed sac enlargement >5 mm. Conclusion: Prophylactic EndoAnchor use for challenging aortic neck anatomy was associated with satisfactory midterm results.
Initial Experience With the Absorb Bioresorbable Vascular Scaffold Below the Knee
Authors: Varcoe Ramon L. , Schouten Olaf , Thomas Shannon D. , Lennox Andrew F.
Published: March 2015

Purpose: To investigate a new bioresorbable vascular scaffold for the treatment of focal tibial and distal popliteal lesions. Methods: Tibial and distal popliteal angioplasty was performed in 15 limbs of 14 patients (9 men; median age 82 years) with critical limb ischemia (CLI, n=7) or severe claudication. The 18 lesions (mean length 22.2±14.0 mm) were implanted with 22 everolimus-eluting bioresorbable scaffolds (Absorb). Clinical and ultrasound follow-up was performed at 1, 3, 6, and 12 months to detect restenosis and evaluate safety, midterm restenosis rate, and clinical improvement. Results: Immediate technical success was 100%, although a single limb suffered 2 scaffold thromboses on the first day; it was salvaged with repeat endovascular intervention. All patients were available for surveillance examinations during a follow-up of 6.1±3.9 months; no patient died. Of the 15 limbs in the analysis, clinical improvement was present in 12 (4 of 7 CLI patients); there was no amputation, bypass surgery, or evidence of binary restenosis on follow-up sonographic examination. Conclusion: Midterm follow-up for this small pilot sample demonstrates acceptable safety and patency results, together with freedom from all major adverse limb events, using the Absorb bioresorbable vascular scaffold below the knee.