bluuebunny/crossref_metadata_2025 huggingface dataset:
A SVECM Analysis of the Relationship between International Tourism Arrivals, GDP and Trade in Italy
Authors: Massidda Carla , Mattana Paolo
Published: September 2012

This article provides an SVECM investigation of long-run, short-run and contemporaneous relationships across per capita international tourism arrivals ( ar), real GDP ( y), and total international commercial transactions ( tr) for the Italian economy. We find that variables span a bidimensional cointegrating space, which we normalize as long-run relationships between y and ar and between ar and tr. Signs and magnitudes of the estimated elasticities are as expected and compare well with the literature. The causation mechanism shows that none of the variables are weakly exogenous. What we find is that, whereas there appears to be unidirectional long-run causality running from y to tr and from tr to ar, bidirectional causality is detected between y and ar. Structural estimation and a study of the Impulse-Response functions of “meaningful” shocks hitting the economy are used to provide valuable insights for policy and business strategy design.
“It Opened My Eyes”
Authors: Picca Leslie H. , Starks Brian , Gunderson Justine
Published: September 2012

Journal writing is pedagogically appropriate for increasing reflexivity and conscious awareness of one’s environment. The journal assignment discussed in this article promotes recognition of the impact of race, gender, and social class on students’ everyday lives. In pre- and posttest surveys of students engaged in this assignment, students report statistically significant increases in awareness after journaling. These increases in awareness are found for students enrolled in introductory courses at two very different universities (one a private Catholic midsized university in the Midwest and the other a large state university in the Southeast). Students’ qualitative responses further substantiate the effectiveness of this assignment in meeting course objectives. To facilitate use of this assignment by others, we identify a set of best practices to help ensure high-quality journals and discuss challenges and benefits of this assignment, including getting to know one’s students.
The influence of talc content on the thermal and mechanical properties of thermoplastic polyurethane/polypropylene blends
Authors: Bajsić Emi Govorčin , Rek Vesna , Pavić Bojana Ormuž
Published: September 2012

The influence of different talc contents on the thermal and mechanical properties of thermoplastic polyurethane/polypropylene (TPU/PP) blends was investigated. The compatibility and crystallinity of TPU/PP and TPU/PP/T blends were determined by differential scanning calorimetry (DSC). The DSC results indicated that the addition of PP in TPU/PP blends increased glass transition temperature ( Tg), melting temperature ( Tm) and crystallinity ( χc). The addition of talc has decreased Tm and χc and increased Tg and crystallization temperature ( Tc). The effect of talc content on Tg, Tm and χc was insignificant, while Tc content increased. The Tg of nonfilled and talc-filled blends increased suggesting that the TPU and PP are partially compatible. Thermogravimetric analysis (TGA) showed improved thermal stability of all investigated nonfilled and talc-filled TPU/PP blends in the nitrogen atmosphere. In the air atmosphere only talc-filled TPU/PP 80/20 blends show a higher thermal stability, while thermal stability decreased for TPU/PP 50/50 and increased insignificantly for TPU/PP 20/80 blends. DSC and TGA results showed improved thermal properties of talc-filled TPU/PP blends when compared with nonfilled blends. The mechanical properties of talc-filled TPU/PP 50/50 and 20/80 blends improved in terms of tensile strength and Young’s modulus, while elongation of break decreased with the addition of talc and as the talc content increased.
Influences of visual feedback indicator scales on human upright postural control
Authors: Pei Lili , Li Hongyi , Fu Yunfa , Yang Yanhua , Li Jiangtao
Published: September 2012

Human upright postural control is highly related to visual information. In order to explore the influence of visual feedback on static upright postural control, postural sway of eight healthy young adults was investigated under visual feedback circumstances. In the investigation, postural feedback information was visualized by an indicator composed of a movable spot and a stationary circle, and in addition to Shannon entropy analysis, time domain and frequency domain analyses were employed to inspect postural control adjustment. The experiment results indicate that even though indicator scale changes do not induce significant postural differences in time domain and random characteristics, reduction of the visual feedback indicator scale inspires a postural power shift to higher frequencies. In addition, this reduction also induces a fall-after-rise pattern of postural energy distribution in the frequency range of 0.5–1 Hz.
Fault detection of networked control systems in stochastic environments
Authors: Yang Junqi , Zhu Fanglai
Published: September 2012

This paper deals with the problem of fault detection for networked control systems in the stochastic environments. The packet dropout, network-induced delay and out-of-order packets due to long delay are assumed to exist stochastically in the sensor-to-controller link and the controller-to-actuator link. By assuming that the stochastic environment could be described as a homogeneous Markovian chain, the networked control system is modelled as a discrete-time, non-uniform sampling stochastic parameter-varying Markov jump system. Based on the model, the residual generator is developed and the problem of fault detection is formatted as a filtering problem. By using the theory of a Markovian jump linear system, a fault detection filter which makes the residual generation system stochastically stable is considered, and a prescribed disturbance attenuation level is satisfied. A sufficient condition to solve this problem is given in terms of the linear matrix inequalities. A numerical example shows that the proposed fault detection filter is sensitive to the fault but robust to exogenous disturbance.
Likelihood-based iteration square-root cubature Kalman filter with applications to state estimation of re-entry ballistic target
Authors: Mu Jing , Cai Yuan-li
Published: September 2012

A new algorithm named the likelihood-based iteration square-root cubature Kalman filter (LISRCKF) is provided in this study. The LISRCKF inherits the virtues of the square-root cubature Kalman filter (SRCKF), which uses the cubature rule-based numerical integration method to calculate the mean and square root of covariance for the non-linear random function. The LISRCKF involves the use of the iterative measurement update and the use of the latest measurement, and the iteration termination criterion based on maximum likelihood is introduced in the measurement update. The LISRCKF algorithm is applied to the state estimation for re-entry ballistic target with unknown ballistic coefficient. Its performance is compared against that of the unscented Kalman filter and SRCKF. Moreover, the suitable choice of iteration number is studied; iteration number 5 is the most appropriate for the LISRCKF algorithm. Simulation results indicate that the LISRCKF algorithm has the features of short run time and fast convergence rate; the advantage in robustness is also demonstrated through the numerical simulation, and it is an effective state estimation method.
Perceived Impact of Cancer Treatment on Diabetes Self-Management
Authors: Hershey Denise Soltow , Tipton Janelle , Given Barbara , Davis Ellen
Published: September 2012

Purpose

The purpose of this study was to identify the impact that cancer and its treatment had on diabetes self-management and to identify common issues that individuals with diabetes encounter while undergoing chemotherapy.

Methods

This exploratory study utilized a baseline self-administered written survey and an 8-week telephone follow-up survey that included 2 open-ended questions. Forty-three adults aged 50 or older with diabetes and a solid tumor cancer receiving chemotherapy were recruited from 8 community outpatient cancer centers in Michigan and Ohio. Descriptives, t tests, and correlations were utilized to analyze the data. Content analysis was used to analyze the data from the open-ended questions.

Results

After a minimum of 8 weeks of chemotherapy, patients performed significantly fewer diabetes self-management behaviors. The majority of individuals experienced a moderate to high impact on their ability to perform diabetes self-management activities while receiving chemotherapy. Exercise, ability to eat and drink, and monitoring blood sugars were most affected. Three themes identifying patient issues were noted: self-management issues, health issues, and prioritization.

Conclusions

Cancer treatment and cancer-related symptoms can have a negative impact on diabetes self-management behaviors in adults with diabetes who are undergoing chemotherapy. Diabetes self-management education is targeted to improve health outcomes in patients with diabetes and cancer and addresses the “cause” not just the “source” of the problem needs to be developed. Further research needs to be done to address issues related to glycemic control and health-related outcomes in this population.
Changing Racial and Poverty Segregation in Large US Metropolitan Areas, 1970–2009
Authors: Madden Janice Fanning
Published: September 2012

As African Americans are poorer than non-African Americans, increasing racial integration might lead to increasing poverty integration. Alternatively, if racial segregation pushed higher- and lower-income African Americans to reside together, increasing racial integration may lead higher-income African Americans to sort into higher-income non-African American neighborhoods, decreasing poverty integration. Using consistently bounded census tract data for thirty-six large metropolitan areas (MAs) from 1970 to 2009, a fixed effect model measures the relationship of a census tract’s end of the decade proportions of the metropolitan population by race and poverty status group between 1980 and 2009 to the proportions of each race and poverty group resident in a census tract at the start of the decade. The article finds that racial integration occurs mostly within own poverty groups and poverty integration occurs mostly within own racial groups, making these integration processes largely independent. Poverty and racial segregation were slightly decreased, however, because the nonpoor racially integrated with the poor in a manner consistent with gentrification and status caste exchange theory.
Parenting Style, Perfectionism, and Creativity in High-Ability and High-Achieving Young Adults
Authors: Miller Angie L. , Lambert Amber D. , Speirs Neumeister Kristie L.
Published: September 2012

The current study explores the potential relationships among perceived parenting style, perfectionism, and creativity in a high-ability and high-achieving young adult population. Using data from 323 honors college students at a Midwestern university, bivariate correlations suggested positive relationships between (a) permissive parenting style and creativity and (b) authoritarian parenting style and socially prescribed perfectionism. Furthermore, negative relationships were also found between authoritarian parenting style and creativity. These relationships were further investigated using a path model that included control variables for gender and parent education level. Findings suggest statistically significant relationships between creativity and gender, authoritarian parenting and socially prescribed perfectionism, authoritarian parenting and creativity, and permissive parenting and creativity.
Health Care Professionals as Second Victims after Adverse Events
Authors: Seys Deborah , Wu Albert W. , Gerven Eva Van , Vleugels Arthur , Euwema Martin , Panella Massimiliano , Scott Susan D. , Conway James , Sermeus Walter , Vanhaecht Kris
Published: September 2012

Adverse events within health care settings can lead to two victims. The first victim is the patient and family and the second victim is the involved health care professional. The latter is the focus of this review. The objectives are to determine definitions of this concept, research the prevalence and the impact of the adverse event on the second victim, and the used coping strategies. Therefore a literature research was performed by using a three-step search procedure. A total of 32 research articles and 9 nonresearch articles were identified. The second victim phenomenon was first described by Wu in 2000. In 2009, Scott et al. introduced a detailed definition of second victims. The prevalence of second victims after an adverse event varied from 10.4% up to 43.3%. Common reactions can be emotional, cognitive, and behavioral. The coping strategies used by second victims have an impact on their patients, colleagues, and themselves. After the adverse event, defensive as well as constructive changes have been reported in practice. The second victim phenomenon has a significant impact on clinicians, colleagues, and subsequent patients. Because of this broad impact it is important to offer support for second victims. When an adverse event occurs, it is critical that support networks are in place to protect both the patient and involved health care providers.
Transformative Sporting Visions
Authors: Travers Ann
Published: September 2012

In this introduction to this special issue on Transformative Visions of Sport I draw attention to the tension critical sport studies scholars are likely to experience between the attention they draw to the role of sport in perpetuating and normalizing various injustices and their own passion for particular sports. It is no accident that most critical sport studies scholars are also huge fans of various competitions/games, and, indeed, I would argue, this may be a requirement for gaining sport literacy. Each of the five articles included in this special issue aims to showcase their author(s) integration of passion for sport with a vision for social change and social justice.
A successful septal ablation of the first septal perforator artery arising from the circumflex artery
Authors: Kilicgedik A , Karabay CY , Aung SM , Guler A , Kalayci A , Izgi A , Kirma C
Published: September 2012

Congenital coronary anomalies are usually incidental, uncommon and asymptomatic. We present a case of a successful septal ablation of the first septal perforator artery arising from the circumflex artery in a patient with symptomatic hypertrophic cardiomyopathy.
UK policy and the low carbon vehicle sector
Authors: Begley Jason , Berkeley Nigel
Published: September 2012

This article analyses and critiques attempts by UK policymakers, driven by environmental and economic concerns, to promote the low carbon vehicle sector. In particular the efforts of government departments such as Business, Innovation and Skills; Transport; Energy and Climate Change; and the Office of Low Emission Vehicles are considered. Key schemes to promote the design, development and purchase of low carbon vehicles and alternatively fuelled vehicles amongst consumers are analysed, most notably from the perspective of sales. The impact of the sector on automotive producers operating in the UK is also assessed. The analysis finds that despite considerable policy attention, consumer demand for low carbon vehicles remains sluggish at best and that policy focus needs to be reconsidered with greater emphasis placed on demand stimulus measures.
Slippery: Field notes in empirical ontology
Authors: Law John , Lien Marianne Elisabeth
Published: September 2012

This paper explores empirical ontology by arguing that realities are enacted in practices. Using the case of Atlantic salmon, it describes a series of scientific and fish-farming practices. Since these practices differ, the paper also argues that different salmon are being enacted within those different practices. The paper explores the precarious choreographies of those practices, considers the ways in which they enact agency and also work to generate Otherness. Finally it emphasises the productivity of practices and notes that they generate not simply particular realities (for instance particular salmon), but also enact a penumbra of not quite realised realities: animals that were almost but not quite created.
Mind your plate! The ontonorms of Dutch dieting
Authors: Mol Annemarie
Published: September 2012

In the Netherlands as elsewhere, the overriding message of most dieting advice is that a person who wants to lose weight needs to overrule the desires of her craving body. Her mind has to put itself in a sovereign position and make ‘good choices’ about what to eat. But there are many ways of doing so. Linking up with different traditions within nutrition science, different dieting techniques enact different versions of food and concern themselves with different bodies. The ideals they strive after and the dangers they warn against are different, too. In short, they incorporate different ontonorms. At the same time, in all the ‘mind your plate’ advice, however varied, bodies figure as endowed with a nature that is problematic under the present cultural circumstances. This is in contrast with advice to ‘enjoy your food’, that targets a body that is not naturally given, but deserves to be cultivated. As I bring out the details of the discrepancies between the ontonorms embedded in different kinds of dieting advice, the term ‘ontonorms’ serves as a methodological tool. It helps to focus the analysis. But this article does not provide a ‘theory of ontonorms’, instead it argues for theoretical fluidity and specificity.
Remplissage Repair—New Frontiers in the Prevention of Recurrent Shoulder Instability
Authors: Franceschi Francesco , Papalia Rocco , Rizzello Giacomo , Franceschetti Edoardo , Del Buono Angelo , Panascì Manlio , Maffulli Nicola , Denaro Vincenzo
Published: September 2012

Background:

An engaging Hill-Sachs lesion is a defect of the humeral head, large enough to cause locking of the humeral head against the anterior corner of the glenoid rim when the arm is at 90° of abduction and more than 30° of external rotation.

Hypothesis:

When Bankart lesions are associated with engaging Hill-Sachs defects, simultaneous Bankart repair and remplissage provide lower recurrence rates than does Bankart repair alone.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Fifty patients (36 men, 14 women) with combined engaging Hill-Sachs and Bankart lesions were evaluated, before and after arthroscopic management, at a minimum follow-up of 2 years. After imaging and arthroscopic assessment, 25 patients underwent remplissage and Bankart repair, and 25 patients received Bankart repair alone. Patients were evaluated using the UCLA, Constant, and Rowe scores, and range of motion was measured using a goniometer. Postoperatively, all patients underwent magnetic resonance imaging to assess the status of healing of the anterior labrum and whether the tenodesis of the infraspinatus covered the Hill-Sachs defect.

Results:

At the last appointment, active forward elevation, external rotation beside the body, internal rotation, and all administered scores were significantly improved compared with baseline assessment, with no statistically significant intergroup differences. A new posttraumatic dislocation occurred in 5 patients, all from the Bankart-only group (20%).

Conclusion:

Remplissage is a safe, relatively short procedure that allows the surgeon to address large humeral defects with a low postoperative recurrence rate. Humeral head large defects predispose to recurrent instability of the shoulder and deserve surgical management.
Chemical healthcare waste management in small Brazilian municipalities
Authors: Ferreira João A , Bila Danielle M , Ritter Elisabeth , Braga Ana CS
Published: September 2012

The disposal of healthcare waste (HCW) seems to have been solved in developed countries, while in most developing countries the problem persists because the disposal methods are expensive and larger than the budget of small- and medium-sized municipalities. The current study evaluates the encapsulation process for the disposal of medical chemical waste. The experiment was developed in the Piraí municipality (Rio de Janeiro State, Brazil) and the chemical wastes were produced in the local public hospital, as well as the 12 units of primary care health services. Chemical waste generated at health services units may include the liquid waste from cleaning materials and disinfectants, expired and unused pharmaceutical products, and cytotoxins. These are all considered hazardous waste products and they must be disposed of via an authorised system at approved sites (e.g. industrial landfills). The process of encapsulating chemical medical waste in concrete (cement, crushed stones and sand) followed by their disposal at sanitary landfills is a procedure that is not considered in Brazilian Legislation. Despite the oversight, this method of disposal was used in the municipality of Piraí, with the approval of the Rio de Janeiro State Agency for Environmental Control. The safety aspects of this method and the limits of its applicability, particularly in small municipalities, were evaluated in this study. The results indicate that, within certain parameters, this method may provide a viable solution for the disposal of HCW in small municipalities.
Does Organizational Justice Matter in the Federal Workplace?
Authors: Cho Yoon Jik , Sai Na
Published: September 2012

The theory of organizational justice has been supported by numerous empirical studies in the private sector. Although public administration scholars have investigated the fairness issue in pay and promotions, the main focus was confined to specific groups such as females and racial minorities. This research seeks to fill the gap by providing some generalizable findings. We investigate the justice issue by considering both individual- and organizational-level factors. By employing hierarchical linear modeling (HLM), the research examines whether the three dimensions of organizational justice—distributive, procedural, and informational justice—and several organizational-level factors affect four outcomes, including expectancy for career development, employee satisfaction, loyalty to senior leadership, and cooperation. The analysis confirms that the three dimensions of organizational justice are substantially associated with those employee attitudes, although organizational-level factors have little impact on them.
The Telework Divide
Authors: Mahler Julianne
Published: September 2012

Telework is an increasingly common feature of government agencies. Long a practice in the private sector, telework is credited with a range of advantages from increased productivity to reduced environmental costs to society. These advantages may not accrue to all employees, however. Large-sample federal government surveys of employees reveal support for many of the claimed advantages of telework, but taken together they also raise significant questions about the seldom-discussed costs of telework: The impact on those barred from telework. In particular, the results reveal what may be disaffection among those whose jobs may be eligible for teleworking under new Office of Personnel Management guidelines, but whose managers have not allowed them to telework. The findings also raise questions about the consequences of expanding telework to larger populations of government workers and suggest the need for further research on the possibility of an emerging telework divide.
A new bench-scale methodology for evaluating the flammability of live forest fuels
Authors: Madrigal Javier , Hernando Carmen , Guijarro Mercedes
Published: September 2012

The present study proposes a new method in order to evaluate the flammability of live plant parts at bench-scale. Flammability parameters were estimated by the use of a mass loss calorimeter, and fuel moisture content was evaluated by the use of moisture analyser. Forest fuels ( Pinus pinaster, Cistus laurifolius, Lavandula stoechas and Daphne gnidium) were monitored under field conditions to detect the changes in the fuel moisture contents during the fire risk season. The combination of two different bench-scale devices (moisture analyser and mass loss calorimeter) guarantees fixed conditions for carrying out laboratory tests (constant bulk density and constant sample dry mass), thus resolving problems detected with other devices and methodologies.
Characterization of hexane pool fires using infrared thermography
Authors: Sudheer S. , Prabhu S. V.
Published: September 2012

This study is an experimental investigation of the influence of shape and diameter on the radiative properties of open pool fires. Circular and square shapes of equivalent surface area are considered. The circular pool diameters are 0.3, 0.5, 0.7, and 1.0 m, and the lengths of the square pools are 0.26, 0.44, 0.62, and 0.89 m. Hexane is used as the fuel in this study. Radiative properties such as flame emissivity, optical thickness, temperature distribution, and emissive power distribution are studied. Mass burning rate of each pool is measured. Flame emissivity values are inferred from the mass burning rate measurements. Using these emissivity values, the temperature and emissive power distributions are computed using infrared thermography. Irradiance values at a distance from pool fires are computed.
Migration Decision-Making Among Mexican Youth
Authors: Tucker Christine M. , Torres-Pereda Pilar , Minnis Alexandra M. , Bautista-Arredondo Sergio A.
Published: September 2012

We explored migration decisions using in-depth, semistructured interviews with male and female youth ages 14 to 24 ( n = 47) from two Mexican communities, one with high and one with low U.S. migration density. Half were return migrants and half were nonmigrants with relatives in the United States. Migrant and nonmigrant youth expressed different preferences, especially in terms of education and their ability to wait for financial gain. Reasons for migration were mostly similar across the two communities; however, the perceived risk of the migration journey was higher in the low-density migration community whereas perceived opportunities in Mexico were higher in the high-density migration community. Reasons for return were related to youths’ initial social and economic motivations for migration. A greater understanding of factors influencing migration decisions may provide insight into the vulnerability of immigrant youth along the journey, their adaptation process in the United States, and their reintegration in Mexico.
Anxiety Disorders and Latinos
Authors: Priest Jacob B. , Denton Wayne
Published: September 2012

Family cohesion has shown to be associated with lower psychological distress and other risk behaviors for Latinos, but little is known about the relationship of family cohesion, family discord, and anxiety disorders. Using data from the National Latino and Asian American Study ( n = 2,554), this study examines the relationship between family functioning and anxiety disorders for an aggregate Latino sample and for Latino subgroups (Mexican, Cuban, Puerto Rican, and Other Hispanic). Results for the aggregate sample suggest that family discord is associated with 12-month prevalence of almost all anxiety disorders for Latinos. On the other hand, strong family cohesion is only associated with generalized anxiety disorder and panic disorder. For the subgroups, different patterns of association were found, suggesting the importance of understanding the heterogeneity of Latino culture when studying and treating anxiety disorders.
Self-assembled photosensitizer-conjugated nanoparticles for targeted photodynamic therapy
Authors: Zhao Linlin , Kim Tae-Hyun , Huh Kang Moo , Kim Hae-Won , Kim So Yeon
Published: September 2012

An effective tumor-targeted drug delivery system for photodynamic therapy was developed by designing ligand-mediated nanoparticles with stable formulations of a hydrophobic photosensitizer. Novel folic acid (FA)-conjugated amphiphilic block copolymers of polyethylene glycol (PEG) and poly-β-benzyl-L-aspartate (PBLA) with the potential to act as pH-responsive drug release reservoirs were synthesized. The photosensitizer, 2,4-diacetyl deuteroporphyrin IX dimethyl ether (DD-PpIX), was conjugated to the copolymers through pH-sensitive hydrazone linkage. The syntheses and compositions of all copolymers were confirmed by 1H NMR measurement. Photosensitizer-conjugated amphiphilic copolymeric nanoparticles (FA-PEG-P(Asp-Hyd)-DD-PpIX) were prepared by micelle formation in aqueous solution. The particle sizes of the FA-PEG-PBLA and FA-PEG-P(Asp-Hyd)-DD-PpIX nanoparticles were determined by light-scattering measurements. The range was 105–298 nm, depending on copolymer molecular weight and composition. Field emission scanning electron microscopy showed that the FA-PEG-P(Asp-Hyd)-DD-PpIX copolymeric nanoparticles were submicron in size and spherical in shape. The results of in vitro release tests showed that the release profiles of DD-PpIX from the nanoparticles were strongly pH-dependent and influenced by the amount of photosensitizer that was conjugated. In vitro tests using HeLa cells indicated that the FA-PEG-P(Asp-Hyd)-DD-PpIX nanoparticles had low dark-toxicity and showed more than 97% of cellular uptake. Based on our results, the FA-PEG-P(Asp-Hyd)-DD-PpIX nanoparticle system could be a promising approach for developing novel photosensitizer delivery carriers for photodynamic therapy.
Rapid hydrothermal flow synthesis and characterisation of carbonate- and silicate-substituted calcium phosphates
Authors: Chaudhry Aqif A , Knowles Jonathan C , Rehman Ihtesham , Darr Jawwad A
Published: September 2012

A range of crystalline and nano-sized carbonate- and silicate-substituted hydroxyapatite has been successfully produced by using continuous hydrothermal flow synthesis technology. Ion-substituted calcium phosphates are better candidates for bone replacement applications (due to improved bioactivity) as compared to phase-pure hydroxyapatite. Urea was used as a carbonate source for synthesising phase pure carbonated hydroxyapatite (CO3-HA) with ≈5 wt% substituted carbonate content (sample 7.5CO3-HA) and it was found that a further increase in urea concentration in solution resulted in biphasic mixtures of carbonate-substituted hydroxyapatite and calcium carbonate. Transmission electron microscopy images revealed that the particle size of hydroxyapatite decreased with increasing urea concentration. Energy-dispersive X-ray spectroscopy result revealed a calcium deficient apatite with Ca:P molar ratio of 1.45 (±0.04) in sample 7.5CO3-HA. For silicate-substituted hydroxyapatite (SiO4-HA) silicon acetate was used as a silicate ion source. It was observed that a substitution threshold of ∼1.1 wt% exists for synthesis of SiO4-HA in the continuous hydrothermal flow synthesis system, which could be due to the decreasing yields with progressive increase in silicon acetate concentration. All the as-precipitated powders (without any additional heat treatments) were analysed using techniques including Transmission electron microscopy, X-ray powder diffraction, Differential scanning calorimetry, Thermogravimetric analysis, Raman spectroscopy and Fourier transform infrared spectroscopy.
Correlates of Reasons for Not Reporting Rape to Police
Authors: Cohn Amy M. , Zinzow Heidi M. , Resnick Heidi S. , Kilpatrick Dean G.
Published: September 2012

Rape tactics, rape incident characteristics, and mental health problems (lifetime depression, PTSD, and substance abuse) were investigated as correlates of eight different reasons for not reporting a rape to police among women who had experienced but did not report a rape to police ( n = 441) within a national telephone household probability sample. Rape tactics (nonmutually exclusive) included drug or alcohol-facilitated or incapacitated rape (DAFR/IR; n = 119) and forcible rape (FR; n = 376). Principal Components Analysis (PCA) was conducted to extract a dominant set of patterns among the eight reasons for not reporting, and to reduce the set of dependent variables. PCA results indicated three unique factors: Not Wanting Others to Know, Nonacknowledgment of Rape, and Criminal Justice Concerns. Hierarchical regression analyses showed DAFR/IR and FR were both positively and significantly associated with Criminal Justice Concerns, whereas DAFR/IR, but not FR, was associated with Nonacknowledgment as a reason for not reporting to police. Neither DAFR/IR nor FR emerged as significant predictors of Others Knowing after controlling for fear of death or injury at the time of the incident. Correlations among variables showed that the Criminal Justice Concerns factor was positively related to lifetime depression and PTSD and the Nonacknowledgement factor was negatively related to lifetime PTSD. Findings suggest prevention programs should educate women about the definition of rape, which may include incapacitation due to alcohol or drugs, to increase acknowledgement and decrease barriers to police reporting.
Zero Benefit
Authors: Hoffman Stephen
Published: September 2012

This study estimates the effect of zero tolerance disciplinary policies on racial disparities in school discipline in an urban district. Capitalizing on a natural experiment, the abrupt expansion of zero tolerance discipline policies in a mid-sized urban school district, the study demonstrates that Black students in the district were disproportionately affected, with an additional 70 Black students per year recommended for expulsion following the policy change. Furthermore, the study uses negative binomial regression discontinuity analysis to explore the effect of expanding zero tolerance on the proportion of days students are suspended. Following the policy change, the already sizeable difference in the proportion of days suspended between Black students and White students increased.
Early stages in the evolution of covert action governance in the United States, 1951–1961
Authors: Gustafson Kristian
Published: September 2012

The U.S. government started to establish a formalised covert action capability only in the late 1940s and early 1950s, in response to the perceived Soviet threat. The difficult process of establishing the first inter-agency management organisation for this new activity, the Psychological Strategy Board, and its successor, the Operational Coordination Board, serves to highlight the peculiar characteristics of covert action and its management. Very little current scholarship deals with inter-agency bodies in the U.S. context, and this article aims to fill this void. The article concludes that while covert action itself remains in the shadows, policy coordination for it must be well-managed at the very centre of government to account for strong policy interests in this activity from other agencies, particularly the Departments of State and Defense. This task is complicated by the nature of U.S. national security architecture and U.S. government culture overall, which poses high structural obstacles to inter-agency cooperation.
Optimization of process parameters for friction stir welding of joining A6061 and A6082 alloys by Taguchi method
Authors: Kumar Sanjay , Kumar Sudhir , Kumar Ajay
Published: September 2012

The friction stir welding is a pioneering solid-state metal joining technique for producing high-quality joints in materials. In this article, Taguchi approach is applied to analyze the optimal process parameters for optimum tensile strength and hardness of welded dissimilar A6061 and A6082 alloys. An orthogonal array of L9 is implemented and the analysis of variance is employed to investigate the importance of parameters on responses. The experimental tests, conducted according to combination of rotational speed, tool tilt and types of tool pin profile parameters. The results indicate that the rotational speed is most significant process parameter that has the highest influence on tensile strength and hardness, followed by tool pin profile and tool tilt. The optimum results verified by conducting confirmation experiments. The predicted optimal value of tensile strength and hardness of dissimilar joints produced by friction stir welding are 267.74 MPa and 80.55 HRB, respectively.
Investigation of the cutting performance of the natural stone block production in quarries with armed-chain cutting machine
Authors: Sariisik Ali , Sariisik Gencay
Published: September 2012

This study examined the block production and cutting performance of a new, domestically produced arm-type quarry chain saw (Demmak ZK-6800). A pilot study was conducted with an armed-chain cutting machine, as an alternative to the diamond wire cutting method, to increase efficiency of block production in natural stone. In order to increase cutting speed performance, the study determined the most appropriately shaped cutting tips of the chain (4 and 8 edges) and their rates of wear. Production rate and mean cutter end consumption were identified in different natural stone quarries. Accordingly, production rate was calculated as 18.75 m2/h in travertine, 9 m2/h in natural stone and 12 m2/h in marble. Mean cutter end consumption was calculated as 0.264 p/m2. It was observed that use of the machine, particularly in natural stone quarries, resulted in production of a larger number of blocks at a lower cost per unit time. It was calculated that block efficiency in natural stone quarries increased to 60–80% values with the use of the armed-chained cutting machine.
Identification of a wheel–rail adhesion coefficient from experimental data during braking tests
Authors: Malvezzi Monica , Pugi Luca , Papini Susanna , Rindi Andrea , Toni Paolo
Published: September 2012

The forces that occur in the wheel–rail interface significantly affect vehicle dynamics, especially in the longitudinal direction. Conventionally, the tangential component of the force exchanged between the rail and the wheel is expressed as the product of the normal component of the force, and the so-called adhesion coefficient. This ratio depends on several parameters that are usually summarized in the term ‘adhesion conditions’. When the adhesion conditions are degraded (for example, in cases of rain, fog, ice, dead leaves, etc.), and the vehicle is accelerating or braking, pure rolling conditions between the wheels and the rails do not hold any more, and macroscopic sliding occurs on one or more of the wheels. The aim of this work is to identify a relationship between adhesion coefficient and some parameters, namely wheel sliding and train speed, starting from a set of experimental measurements, obtained from test runs conducted with artificially degraded adhesion conditions.
A laboratory study of rail–wheel interaction monitoring using acoustic emission: Effect of rolling conditions with and without lateral rattling
Authors: Thakkar Nirav A , Steel John A , Reuben Robert L
Published: September 2012

This paper presents part of an extended laboratory study on the potential to apply the acoustic emission (AE) technique for in-situ rail–wheel interaction monitoring using rail-mounted sensors. The essential monitoring principle is that the intensity of the rail–wheel contact will affect the intensity of the AE that is generated during rolling. The current paper is confined to situations of ‘normal’ rolling, investigating the effects of wheel load, speed and lateral rattling of the generated AE, although the wider study includes the effects of rail and wheel irregularities on the AE generated. Rail–wheel contact was simulated on a scaled test rig consisting of a single wheel rolled round a circular track using a motor mounted at the centre of the track attached to a driving arm. AE was recorded at a fixed point on the track while the wheel was rolled around the track at a range of speeds with varying axle load. Wheel slip was found to be insignificant and tests using a simulated source confirmed that the energy recorded with a source at a given position on the track was repeatable. In one set of experiments, measures were taken to eliminate lateral rattling of the wheel and eccentricity of the wheel arc relative to the track arc. In a second set of experiments, some lateral float of the wheel along the axle was allowed and a limited amount of eccentricity was built into the track. The energy per wheel rotation for normal rolling was found to increase in a linear fashion with increasing axle load and centrifugal force, as would be expected due to the increasing rolling resistance with axle load and increasing lateral force with angular speed. The frictional instability associated with the lateral rattling was clearly detectible at low axle loads and lower speeds, and both natural and eccentricity (flange rubbing) rail abnormalities were detectible in the AE record. It is concluded that, with appropriate calibration, contact stresses between wheel and rail on straight or curved track can be monitored using track-mounted sensors so that cumulative contact stress can potentially be monitored.
Representation of mechanic hysteresis in a railway track using the Preisach model
Authors: Koc Wladyslaw , Wilk Andrzej , Chrostowski Piotr , Grulkowski Slawomir
Published: September 2012

This paper presents an implementation of the classic scalar Preisach model to describe the hysteresis phenomenon created in a railway track subjected to lateral (in the horizontal plane) displacements. The principles of the Preisach theory and the scalar mathematical model of the mechanical hysteresis that is based on statistically distributed modified hysteresis operators are briefly presented. This article presents the characteristic states of the track displacements under lateral forces and their interpretation using the Preisach phase diagram. Formulas are presented that allow the calculation of the trajectory of the track displacements using the Preisach distribution function (PDF) and the Everett function (EF). Identification methods for the PDF and EF presented in the literature are discussed. A mathematical formula for the calculation of the EF on the basis of the major hysteresis loop is presented. The implemented hysteresis model is validated by comparing simulation results with experimental data. A good level of agreement between the two sets of results is observed which confirms the validity of the proposed model. The shape of the hysteresis loop created in the rail track depends on the stress state in the rails. It is suggested that this observation could be used to create an effective method to assess axial forces in continuous welded rail track.
Quantification of the effect of cross-shear and applied nominal contact pressure on the wear of moderately cross-linked polyethylene
Authors: Abdelgaied Abdellatif , Brockett Claire L , Liu Feng , Jennings Louise M , Fisher John , Jin Zhongmin
Published: September 2012

Polyethylene wear is a great concern in total joint replacement. It is now considered a major limiting factor to the long life of such prostheses. Cross-linking has been introduced to reduce the wear of ultra-high-molecular-weight polyethylene (UHMWPE). Computational models have been used extensively for wear prediction and optimization of artificial knee designs. However, in order to be independent and have general applicability and predictability, computational wear models should be based on inputs from independent experimentally determined wear parameters (wear factors or wear coefficients). The objective of this study was to investigate moderately cross-linked UHMWPE, using a multidirectional pin-on-plate wear test machine, under a wide range of applied nominal contact pressure (from 1 to 11 MPa) and under five different kinematic inputs, varying from a purely linear track to a maximum rotation of ±55°. A computational model, based on a direct simulation of the multidirectional pin-on-plate wear tester, was developed to quantify the degree of cross-shear (CS) of the polyethylene pins articulating against the metallic plates. The moderately cross-linked UHMWPE showed wear factors less than half of that reported in the literature for the conventional UHMWPE, under the same loading and kinematic inputs. In addition, under high applied nominal contact stress, the moderately cross-linked UHMWPE wear showed lower dependence on the degree of CS compared to that under low applied nominal contact stress. The calculated wear coefficients were found to be independent of the applied nominal contact stress, in contrast to the wear factors that were shown to be highly pressure dependent. This study provided independent wear data for inputs into computational models for moderately cross-linked polyethylene and supported the application of wear coefficient–based computational wear models.
From Karen to Katie
Authors: Berger Jonah , Bradlow Eric T. , Braunstein Alex , Zhang Yao
Published: September 2012

How do psychological processes shape how culture evolves? We investigated how a cultural item's popularity is shaped by the recent popularity of other items with features in common. Specifically, using more than 100 years of first-names data, we examined how a name’s popularity is influenced by the popularity of that name’s component phonemes in other names in the previous year. Building on mere-exposure research, we found that names are more likely to become popular when similar names have been popular recently. These effects are nonlinear, however, and overpopularity hurts adoption. In addition, these effects vary with phoneme position. We demonstrate the causal impact of similarity on cultural success in a natural experiment using hurricane names. An exogenous shock to a phoneme’s frequency, due to the presence of the phoneme in the names of prominent hurricanes, boosts the popularity of names that share that phoneme. Taken together, our results suggest how the similarity between cultural items affects how popular they become and how culture evolves more broadly.
Annual chronology and climate response in Abies guatemalensis Rehder (Pinaceae) in Central America
Authors: Anchukaitis Kevin J , Taylor Matthew J , Martin-Fernandez Javier , Pons Diego , Dell Malcolm , Chopp Christopher , Castellanos Edwin J
Published: September 2012

The continued expansion of dendroclimatology into Mesoamerica requires the identification and evaluation of species whose rings can be precisely dated and then statistically compared with precipitation and temperature variability in order to make inferences about past climate. Here, we establish the basis for using Abies guatemalensis Rehder (Pinaceae) for climate reconstruction in Central America. Annual crossdating in this montane species is demonstrated at high-elevation sites in the Sierra de los Cuchumatanes in western Guatemala. We find that ring width is most strongly influenced by early growing season moisture conditions, controlled by late dry season rainfall, and negatively correlated with growing season temperature. Our chronology is also significantly negatively correlated with eastern tropical Pacific sea surface temperature anomalies. Our confirmation of annual chronology and the identification of a climatic signal in this species now allow its use in local and regional paleoclimate reconstructions, as well as ecological studies.