bluuebunny/crossref_metadata_2025 huggingface dataset:
Exploring Student Conceptions of Modeling and Modeling Uses in Engineering Design
Authors: Carberry Adam R. , McKenna Ann F.
Published: February 2014

Background

Modeling is a pervasive feature of engineering that is rarely taught explicitly to engineering students. The implicit inclusion of modeling often results in conceptions held by students of models based on the everyday use of the term that neglects important predictive types of models.

Purpose

We studied the effectiveness of an explicit modeling module designed to broaden student understandings of various approaches to and applications of modeling.

Design/Method

A two‐phase analysis of student conceptions was undertaken. Phase I analyzed the conceptions of an experimental group before and after they were taught an explicit modeling module. Phase II added a comparison group at a second institution.

Results

A significant shift was observed for engineering students who were explicitly taught a modeling module. Student‐held conceptions were predominantly descriptive‐centric (e.g., physical models) throughout the investigation with an added focus on predictive (e.g., mathematical) modeling after completing the modeling module. These results were consistent for a comparison group.

Conclusions

Explicit learning experiences about models and the modeling process need to be embedded into the engineering curriculum, specifically in the teaching of engineering design. Teaching modeling will improve student use and understanding of modeling as an important and pervasive engineering tool.
Sustainability as a Route to Broadening Participation in Engineering
Authors: Klotz Leidy , Potvin Geoff , Godwin Allison , Cribbs Jennifer , Hazari Zahra , Barclay Nicole
Published: February 2014

Background

Sustainability is increasingly a vital consideration for engineers. Improved understanding of how attention to sustainability influences student major and career choice could inform efforts to broaden participation in engineering.

Purpose

Two related questions guided our research. How do career outcome expectations related to sustainability predict the choice of an engineering career? Which broader sustainability‐related outcomes do students perceive as related to engineering? To address both questions, we compared effects for engineering and nonengineering students while controlling for various confounding variables.

Design/Method

We conducted a survey to collect responses about sustainability and other variables of interest from a national sample of college students in introductory English classes. Data were analyzed using descriptive statistics and correlational analysis.

Results

Students who hope to address certain sustainability issues such as energy, climate change, environmental degradation, and water supply are more likely to pursue engineering. Those who hope to address other sustainability issues such as opportunities for women and minorities, poverty, and disease are less likely to do so. Students hoping to address sustainability‐related outcome expectations with obvious human relevance are less likely to pursue engineering. Yet those students who perceive “improving quality of life” and “saving lives” as associated with engineering are more likely to pursue the profession.

Conclusions

Our results suggest that showing students the connection between certain sustainability issues and engineering careers could help those striving to increase and diversify participation in engineering. A broader range of engineers would likely bring new ideas and ways of thinking to engineering for sustainability.
Marginalized Identities of Sense‐Makers: Reframing Engineering Student Retention
Authors: Danielak Brian A. , Gupta Ayush , Elby Andrew
Published: February 2014

Background

Students' identities and sense of belonging in a program affect whether they stay in engineering. Research suggests that students' ways of knowing and beliefs about what counts as knowing and learning – their personal epistemologies – can be aspects of their identities, or sense of self as knowers and learners.

Purpose/Hypothesis

Combining personal epistemology and identity theories suggests epistemological aspects of students' identities can influence whether they feel they belong in their engineering program. We have two research questions: Can a high‐achieving engineering student be in danger of leaving a program because of a mismatch between epistemological aspects of his identity and his perceptions of the intellectual climate of their program? How does such a mismatch affect the student's day‐to‐day academic experiences?

Design/Method

For three years, we followed Michael, an electrical engineering student, through interviews and in‐class observations. From more than 12 hours of semistructured clinical interviews, more than 10 hours of videotaped discussion sections, and two in‐class observations in lectures, we produced a case study to characterize epistemological aspects of Michael's identity and how they influenced his perception of his program.

Results

Michael expressed and enacted a sense‐making epistemology that is a fundamental aspect of his identity as a learner. Due to this sense‐making aspect of Michael's identity, he often felt alienated from the intellectual climate of his program, and he considered leaving engineering.

Conclusion

Researchers focused on student retention should attend to epistemological aspects of student identities. Instructors and administrators focused on retention should attend to the epistemological messages students hear from their programs.
Design and Effectiveness of Modeling‐Based Mathematics in a Summer Bridge Program
Authors: Doerr Helen M. , Ärlebäck Jonas B. , Costello Staniec Andria
Published: February 2014

Background

Since students' success in their first‐semester college mathematics course is a key factor in their success in engineering, many summer bridge programs for underrepresented students focus on their preparation in mathematics. However, research on the design and efficacy of such programs is limited. We examine the design and effectiveness of a modeling‐based approach to mathematics for entering freshmen engineering students.

Purpose

The study addresses two questions: Does a modeling‐based mathematics course in a bridge program positively affect students' performance in their first‐semester college mathematics course? To what extent does a sequence of modeling tasks support the development of students' concepts of average rates of change?

Design/Method

This quasi‐experimental study compared two cohorts of bridge program students over six years to examine the effectiveness of a modeling‐based mathematics course on first‐semester mathematics course grades. Pre‐ and post–tests measured changes in students' concepts of average rates of change.

Results

The modeling‐based mathematics course closed the previous letter grade gap between bridge program participants and non‐participants in the first mathematics course. We also found significant course grade gains for students who took the modeling‐based mathematics course compared with a previous cohort who took a traditional summer mathematics course.

Conclusions

These results suggest that the modeling‐based mathematics course, with its focus on the development of engineering students' abilities to model changing phenomena, was effective in improving students' concepts of average rate of change and their first‐semester mathematics course grade.
Effect of biofuel‐derived contaminants on coated industrial gas turbines blade materials
Authors: Encinas‐Oropesa A. , Simms N. J. , Nicholls J. R. , Oakey J. E. , Heikinheimo L. , Tuurna S.
Published: February 2014

Combined cycle power systems offer increased efficiency of electricity generation and lower environmental emissions of CO2, SOx and NO2, as well as being adaptable to most fossil/biofuels. Industrial gas turbines are at the heart of such power stations and are being developed to perform at higher firing temperatures and pressures to achieve even greater efficiencies, with lower emissions. Fuel gases derived from renewable fuels, such as biogases from digestors or syngases from solid fuel gasification, may contain contaminants that are extremely corrosive to the gas turbine components (e.g. blades and vanes) located in the hot combusted gas path. Such damage can result in a gradual loss of turbine efficiency and reliability. Therefore, it is of paramount importance that the materials used for gas turbine components that operate in these environments provide acceptable and predictable in‐service life times. Single crystal superalloys (e.g. CMSX‐4) were developed to have improved mechanical properties (creep and fatigue) at increasing component operating temperatures, especially in relatively clean aero‐engine operating environments. This paper describes work carried out to investigate the development of hot corrosion processes on CMSX‐4 (uncoated and Pt‐Al coated) in a range of potential environments for blade materials in industrial gas turbines fired on biomass derived fuel gases. A series of laboratory tests has been carried out using the ‘deposit recoat’ technique, with exposure conditions covering: deposits of 80/20 and 50/50 (Na/K)2SO4, with additions of lead, a gas composition of 100 vpm SOx, 100 vpm HCl in simulated combustion gases, deposition flux of 15 µg/cm2/h, temperature of 700 °C, for periods up to 1000 h. During their exposure the materials were monitored using traditional mass change methods. However, quantitative damage data in terms of metal loss was obtained using dimensional metrology, pre‐exposure contact measurements combined with post‐exposure measurements of damage observed by optical microscopy on polished cross‐sections. These measurement methods allowed the distribution of damage to be determined and the material sensitivity to such hot corrosion processes to be quantified.
Cyclic long‐term testing of gas turbine burner materials in reducing environments at 700 °C
Authors: Viklund P. , Norling R.
Published: February 2014

Gas turbines operating under fuel‐rich conditions may suffer from material degradation and metal dusting. To evaluate this cyclic exposures have been done at 700 °C during 5000 h in two synthetic environments having a carbon activity of 0.26 and above unity. It was found that the common stainless steel 304L is incapable of withstanding either of the environments, while the stainless steel 253MA performs well because a protective silica layer is formed. The ferritic alumina formers Kanthal APM and Kanthal APMT perform well, together with several commercial chromia forming Ni‐base alloys. As a general trend the material degradation is slower in the environment with the higher carbon activity, but pre‐oxidised samples of chromia forming alloys did experience sudden and rapid carburisation after scale failure. Also a TBC system failed earlier in this environment, because graphite formation at the top coat/bond coat interface caused spalling of the top coat. Further the MCrAlY bond coat cracked and caused carburisation of the underlying Ni‐based substrate. A silicon modified aluminide coating showed good degradation resistance, but stimulated excessive carbon deposition in the environment of high carbon activity.
Effect of oxy‐firing on corrosion rates at 600–650 °C
Authors: Pint B. A. , Thomson J. K.
Published: February 2014

Because of higher CO2, and possibly H2O and SO2, levels in the boiler, there are concerns about increased corrosion rates after retrofitting current coal fired boilers from air‐firing to oxy‐firing to assist in CO2 capture. The oxidation behavior of a combination of commercial and model alloys were investigated both with and without the presence of synthetic coal ash at 600 and 650 °C. At 600 °C, a CO2–H2O environment showed the most rapid oxidation rate for Fe‐based alloys with <20% Cr and varying the CO2 content or adding a 0.15% O2 buffer had little effect on the mass change. However, at 650 °C, the O2‐buffered CO2–H2O environment showed a similar rate of oxidation as 100% H2O, again requiring more than 20% Cr for a thin protective Cr‐rich oxide to form. With synthetic coal ash, increasing the CO2, H2O, and/or SO2 levels in the gas phase tended to show a lower oxide thickness after a 500 h exposure at 600 °C, compared to the base line air‐firing condition. At 650 °C, no systematic increase in the reaction rate was observed when switching from the air firing to the oxy‐firing gas. These simulations suggest that higher CO2 contents with oxy‐firing do not increase the rate of oxidation.
Involvement of Urokinase‐Type Plasminogen Activator System in Cancer: An Overview
Authors: Mekkawy Ahmed H. , Pourgholami Mohammad H. , Morris David L.
Published: February 2014

Currently, there are several studies supporting the role of urokinase‐type plasminogen activator (uPA) system in cancer. The association of uPA to its receptor triggers the conversion of plasminogen into plasmin. This process is regulated by the uPA inhibitors (PAI‐1 and PAI‐2). Plasmin promotes degradation of basement membrane and extracellular matrix (ECM) components as well as activation of ECM latent matrix metalloproteases. Degradation and remodeling of the surrounding tissues is crucial in the early steps of tumor progression by facilitating expansion of the tumor mass, release of tumor growth factors, activation of cytokines as well as induction of tumor cell proliferation, migration, and invasion. Hence, many tumors showed a correlation between uPA system component levels and tumor aggressiveness and survival. Therefore, this review summarizes the structure of the uPA system, its contribution to cancer progression, and the clinical relevance of uPA family members in cancer diagnosis. In addition, the review evaluates the significance of uPA system in the development of cancer‐targeted therapies.
Solution‐processed high‐performance orange phosphorescent and white PLEDs with a high color‐rendering index from an unprecedented π‐stacked and π‐conjugated host material
Authors: Ye Shang‐Hui , Yin Cheng‐Rong , Zhou Zhou , Hu Tian‐Qing , Li Yong‐Hua , Li Lu , Xie Ling‐Hai , Huang Wei
Published: February 2014

A blue fluorescent polymer based on poly(vinyl carbazole) (PVK) and terfluorene, combined to make a chemical hybrid at the carbazole unit (PVK‐TF), is fully characterized in this study. PVK‐TF shows useful emission features, such as peaks at 400, 420, 437, 460, and 496 nm, depending on the processing conditions. It possesses a relatively high triplet energy level (2.23 eV), electrochemical stability, good film‐forming ability, and morphological stability. Based on this blue fluorescent material, highly efficient orange phosphorescent polymer light‐emitting diodes (PLEDs) were fabricated with a maximum efficiency of 21.99 cd A−1, and a maximum luminance of 19552.3 cd m−2. Single‐layer hybrid white PLEDs were developed, with a high color rendering index of 81.9 that emitted across the whole visible spectrum from 380 to 780 nm, corresponding to the Commission International de L'Eclairage coordinates x, y values of around (0.38, 0.40) and CCT = 3774, with a maximum current efficiency of 10.69 cd A−1, and a maximum brightness of 15723.3 cd m−2. © 2014 Wiley Periodicals, Inc. J. Polym. Sci. Part B: Polym. Phys. 2014, 52, 587–595
Prediction of Sensitivity of Energetic Compounds with a New Computer Code
Authors: Keshavarz Mohammad Hossein , Motamedoshariati Hadi , Moghayadnia Reza , Ghanbarzadeh Majid , Azarniamehraban Jamshid
Published: February 2014

Impact, electrostatic, and shock sensitivities of energetic compounds are three important parameters for the assessment of hazardous energetic materials. A novel easy to handle and user‐friendly computer code, written in Visual Basic, is introduced to predict these parameters, by solely using the molecular structure of an energetic molecule. It is able to predict impact sensitivity for different types of energetic compounds including nitropyridines, nitroimidazoles, nitropyrazoles, nitrofurazanes, nitrotriazoles, nitropyrimidines, polynitro arenes, benzofuroxans, polynitro arenes with α‐CH, nitramines, nitroaliphatics, nitroaliphatic containing other functional groups, and nitrate energetic compounds. It can also provide reliable results for electrostatic and shock sensitivities of some classes of high explosives including nitroaromatic and nitramine compounds. The prediction of this code give good values for some newly reported energetic compounds, where experimental data are available.
Approximate dynamic programming via iterated Bellman inequalities
Authors: Wang Yang , O'Donoghue Brendan , Boyd Stephen
Published: February 2014

In this paper, we introduce new methods for finding functions that lower bound the value function of a stochastic control problem, using an iterated form of the Bellman inequality. Our method is based on solving linear or semidefinite programs, and produces both a bound on the optimal objective, as well as a suboptimal policy that appears to works very well. These results extend and improve bounds obtained in a previous paper using a single Bellman inequality condition. We describe the methods in a general setting and show how they can be applied in specific cases including the finite state case, constrained linear quadratic control, switched affine control, and multi‐period portfolio investment. Copyright © 2014 John Wiley & Sons, Ltd.
Solvothermal‐Induced Self‐Assembly of Fe2O3/GS Aerogels for High Li‐Storage and Excellent Stability
Authors: Wang Ronghua , Xu Chaohe , Du Meng , Sun Jing , Gao Lian , Zhang Peng , Yao Heliang , Lin Chucheng
Published: February 2014

A novel solvothermal‐induced self‐assembly approach, using colloid sol as precursor, is developed to construct monolithic 3D metal oxide/GS (graphene sheets) aerogels. During the solvothermal process, graphene oxide (GO) is highly reduced to GS and self‐assembles into 3D macroscopic hydrogels, accompanying with in situ transformation of colloid sol to metal oxides. As a proof of concept, Fe2O3/GS aerogels are synthesized based on Fe(OH)3 sol, in which GS self‐assemble into an interconnected macroporous framework and Fe2O3 nanocrystals (20–50 nm) uniformly deposit on GS. Benefitting from the integration of macroporous structures, large surface area, high electrical conductivity, and good electrode homogeneity, the hybrid electrode manifests a superior rate capability (930, 660 and 520 mAh g−1 at 500, 2000 and 4000 mA g−1, respectively) and excellent prolonged cycling stability at high rates (733 mAh g−1 during 1000 charge/discharge cycles at 2000 mA g−1), demonstrating its great potential for application in high performance lithium ion batteries. The work described here provides a versatile pathway to construct various graphene‐based hybrid aerogels.
Preparation and Properties of a Graphene Oxide Intercalation Compound Utilizing Hydrocalumite Layered Double Hydroxide as Host Structure
Authors: Plank Johann , Zou Nan , Zhao Zongbin , Dekany Imre
Published: February 2014

Particularly small graphene oxide (GO) nano sheets were synthesized and intercalated into a hydrocalumite type layered double hydroxide (Ca2Al‐LDH) host structure. Synthesis of the GO intercalation compound was performed via controlled rehydration of tricalcium aluminate (Ca3Al2O6) in the presence of GO. Formation of Ca2Al‐GO‐LDH was evidenced from elemental, thermogravimetric, IR spectroscopy, XRD, and SAXS analysis. From the latter, an interlayer distance of 1.05 nm (d value) was found, indicating that one GO sheet is sandwiched by [Ca2Al(OH)6]+ main sheets. SAXS analysis revealed a length of the lamellar structure of 109 nm and presence of agglomerates of randomly stacked nanosized LDH fragments. The carbon content of the Ca2Al‐GO‐LDH particles (thickness ca. 30 nm) was significantly higher than that found for Ca2Al‐OH‐LDH holding surface adsorbed GO only (14 wt % vs. < 2 wt %). GO can be released easily from the inorganic host structure by anion exchange, e.g. with sulfate. The novel compound could present an interesting precursor for electronic applications after chemical reduction of GO to graphene.
Comparison of the Rancimat and the ACL Instrument for Measuring the Oxidative Stability of Corn Oil
Authors: Bell Charlotte , Käser Fabian , Martin Elaine , Scott Gordon
Published: February 2014

A comparison was undertaken between two machines that utilise accelerated methods to measure oxidative stability: the Rancimat (Metrohm, Switzerland) and the single channel chemiluminescence instrument (ACL Instruments, Switzerland). The results from the machines showed good correlation for the measurement of the oxidation induction time of corn oil. For the ACL Instrument, the effect of the sample holder material (aluminium or borosilicate glass) was also investigated and clear differences were noted. Finally, a stability study was carried out over a period of 6 months, with corn oil, stored in the dark at three temperatures: ~4, ~27, ~40 °C and it was observed that it was possible to track subtle changes in oxidative stability using chemiluminescence.
Similarities and differences in the biochemical and enzymological properties of the four isomaltases from Saccharomyces cerevisiae
Authors: Deng Xu , Petitjean Marjorie , Teste Marie-Ange , Kooli Wafa , Tranier Samuel , François Jean Marie , Parrou Jean-Luc
Published: February 2014

The yeast Saccharomyces cerevisiae IMA multigene family encodes four isomaltases sharing high sequence identity from 65% to 99%. Here, we explore their functional diversity, with exhaustive in‐vitro characterization of their enzymological and biochemical properties. The four isoenzymes exhibited a preference for the α‐(1,6) disaccharides isomaltose and palatinose, with Michaëlis–Menten kinetics and inhibition at high substrates concentration. They were also able to hydrolyze trisaccharides bearing an α‐(1,6) linkage, but also α‐(1,2), α‐(1,3) and α‐(1,5) disaccharides including sucrose, highlighting their substrate ambiguity. While Ima1p and Ima2p presented almost identical characteristics, our results nevertheless showed many singularities within this protein family. In particular, Ima3p presented lower activities and thermostability than Ima2p despite only three different amino acids between the sequences of these two isoforms. The Ima3p_R279Q variant recovered activity levels of Ima2p, while the Leu‐to‐Pro substitution at position 240 significantly increased the stability of Ima3p and supported the role of prolines in thermostability. The most distant protein, Ima5p, presented the lowest optimal temperature and was also extremely sensitive to temperature. Isomaltose hydrolysis by Ima5p challenged previous conclusions about the requirement of specific amino acids for determining the specificity for α‐(1,6) substrates. We finally found a mixed inhibition by maltose for Ima5p while, contrary to a previous work, Ima1p inhibition by maltose was competitive at very low isomaltose concentrations and uncompetitive as the substrate concentration increased. Altogether, this work illustrates that a gene family encoding proteins with strong sequence similarities can lead to enzyme with notable differences in biochemical and enzymological properties.
The DNA intercalators ethidium bromide and propidium iodide also bind to core histones
Authors: Banerjee Amrita , Majumder Parijat , Sanyal Sulagna , Singh Jasdeep , Jana Kuladip , Das Chandrima , Dasgupta Dipak
Published: February 2014

Eukaryotic DNA is compacted in the form of chromatin, in a complex with histones and other non‐histone proteins. The intimate association of DNA and histones in chromatin raises the possibility that DNA‐interactive small molecules may bind to chromatin‐associated proteins such as histones. Employing biophysical and biochemical techniques we have characterized the interaction of a classical intercalator, ethidium bromide (EB) and its structural analogue propidium iodide (PI) with hierarchical genomic components: long chromatin, chromatosome, core octamer and chromosomal DNA. Our studies show that EB and PI affect both chromatin structure and function, inducing chromatin compaction and disruption of the integrity of the chromatosome. Calorimetric studies and fluorescence measurements of the ligands demonstrated and characterized the association of these ligands with core histones and the intact octamer in absence of DNA. The ligands affect acetylation of histone H3 at lysine 9 and acetylation of histone H4 at lysine 5 and lysine 8 ex vivo. PI alters the post‐translational modifications to a greater extent than EB. This is the first report showing the dual binding (chromosomal DNA and core histones) property of a classical intercalator, EB, and its longer analogue, PI, in the context of chromatin.
Audit of cesarean delivery in Burkina Faso
Authors: Kouanda Seni , Coulibaly Abou , Ouedraogo Ali , Millogo Tieba , Meda Bertrand I. , Dumont Alexandre
Published: February 2014

Objective

To assess the level and determinants of unnecessary cesarean delivery.

Methods

In a retrospective study, the medical charts were reviewed for 300 low‐risk women who underwent intrapartum cesarean delivery at 10 referral hospitals in Burkina Faso between May 2009 and April 2010. In this context, cesarean deliveries were delegated to clinical officers who have less training than doctors.

Results

Among the 300 study patients, 223 women (74.3%) were referred from primary healthcare facilities. The reason for referral was not medically justified for 35 women. Cesarean was performed by a gynecologist–obstetrician (46.0%), a trained doctor (35.0%), or a clinical officer (19.0%). Acute fetal distress and fetopelvic disproportion were the main indications recorded for intrapartum cesarean delivery. These diagnoses were not confirmed by an obstetrician–gynecologist in 12.0% of cases. Clinical officers were associated with a higher risk of unnecessary cesarean delivery compared with gynecologist–obstetricians by multivariate analysis (odds ratio, 4.46; 95% confidence interval, 1.44–13.77; P = 0.009).

Conclusion

Verification of cesarean indications by highly qualified personnel (i.e. second opinion), in‐service training, and supervision of health workers in primary healthcare facilities might improve the performance of the referral system and help to reduce unnecessary cesarean deliveries in Burkina Faso.
Decreased Physical Activity Attributable to Higher Body Mass Index Influences Fibromyalgia Symptoms
Authors: Vincent Ann , Clauw Daniel , Oh Terry H. , Whipple Mary O. , Toussaint Loren L.
Published: February 2014

Background

Although previous studies report associations between increased body mass index (BMI) and fibromyalgia symptoms, there is uncertainty as to whether this relationship is driven by physical factors, psychological factors, or both.

Objective

To assess these relationships in a clinical sample of patients with fibromyalgia.

Design

Cross‐sectional study.

Setting

Tertiary care facility.

Patients

A total of 686 patients from an existing national fibromyalgia registry.

Methods

Patients completed a demographic form and self‐report questionnaires including the Fibromyalgia Impact Questionnaire–Revised (FIQ‐R), the Medical Outcomes Study Short Form–36 (SF‐36), the Brief Pain Inventory (BPI), and the 30‐item Profile of Mood States (30‐item POMS).

Main Outcome Measurements

FIQ‐R overall impact subscale.

Results

BMI was significantly correlated with fibromyalgia impact (P < .001). The relationship between BMI and fibromyalgia impact was almost fully accounted for by physical factors and not by psychological factors.

Conclusions

Despite patient report that pain hinders physical activity, clinicians who encounter patients with fibromyalgia, particularly patients with increased BMI, should be cognizant of the need to invest time and resources to counsel patients on physical factors (ie, physical activity) that could improve the patients' symptom experience.
Environmental interpretation of fossil insect assemblages from MIS 5 at Ziegler Reservoir, Snowmass Village, Colorado
Authors: Elias Scott A.
Published: February 2014

Organic-rich lake sediments from a trench exposed at the Ziegler Reservoir fossil site near Snowmass Village, Colorado yielded a sequence of 27 insect fossil assemblages, spanning the time interval from about 125 to 77 ka. The assemblages appear to represent MIS 5e, 5c, 5b, and 5a. A total of 99 taxa were identified, mostly beetles. The fossils represent the oldest known Pleistocene insect faunas from high elevation in the Rocky Mountains, and document a series of climatic oscillations from full interglacial to stadial and interstadial environments, accompanied by changes in regional biological communities. The MIS 5e fauna indicates summer temperatures similar to modern values, with winter temperatures 5–7 °C cooler than today. Regional climates cooled somewhat by MIS 5c, and during MIS 5b summer temperatures were 5–6 °C colder than modern values. Summer temperatures recovered to near-modern levels during early MIS 5a, and cooled by 1–2 °C at its end, although winter temperatures were apparently above modern levels. The indication of milder but wetter winters, strengthened by the inclusion of species found today only in the Pacific Northwest region, suggests conditions that may have led to increased snowpack at high elevations in this part of the Rocky Mountains, linked with the onset of MIS 4 glaciation.
Rights Mobilization and the Campaign to Decriminalize Homosexuality in Singapore
Authors: Chua Lynette J.
Published: February 2014

This paper analyzes how activists used a parliamentary petition to overcome legal and political barriers and mobilize openly for gay rights for the first time in Singapore. Unlike societies where rights mobilization has political legitimacy, exercising and claiming rights in thede factoone-party state are non-conformist behaviours and face greater limitations. Gay rights activists in Singapore not only struggle with the state and their opponents over the right to equality; compared to their counterparts in liberal democracies, they also have to overcome stronger restrictions on political access and civil-political liberties that enable or protect rights mobilization. This paper therefore describes and analyzes a politics of rights under authoritarian conditions and the complicated consequences of legal resistance and rights mobilization. Although the petition campaign transformed collective grievances, expanded activists’ support base, and opened up new tactical possibilities, it also provoked intense, third-party opposition and foreclosed other avenues of mobilization.
Primary melanoma of the cochlea with cerebellopontine extension and leptomeningeal spread
Authors: Koshy A N , Briggs R J , Dally M
Published: February 2014

Background:

Less than 1 per cent of tumours occurring in the region encompassing the internal auditory canal and the cerebellopontine angle are malignant. Primary central nervous system melanomas arising from this region are exceptionally rare and are often initially misdiagnosed as acoustic neuromas.

Methods:

We present a 71-year-old man with acute vestibular disturbance and unilateral hearing loss. Magnetic resonance imaging demonstrated a mass, thought to be a cochlear nerve schwannoma, involving the cochlea and the internal auditory canal. At surgery, a pigmented mass adherent to the facial nerve was visualised, and the observed histopathology was consistent with a malignant melanoma. No extracranial site for the primary tumour was found, suggestive of a primary central nervous system melanoma.

Results:

Despite surgical resection and adjuvant radiotherapy, the patient re-presented with extensive leptomeningeal disease 16 months later.

Conclusion:

Malignant tumours in the internal auditory canal and cerebellopontine angle region are rare. Early diagnosis and management are aided by recognition of characteristic factors such as a history of prior malignancy, atypical magnetic resonance imaging findings and accelerated audiovestibular symptoms. Despite the presented patient's outcome, total surgical resection with post-operative radiotherapy remains the recommended treatment.
Sociodemographic and career history predictors of suicide mortality in the United States Army 2004–2009
Authors: Gilman S. E. , Bromet E. J. , Cox K. L. , Colpe L. J. , Fullerton C. S. , Gruber M. J. , Heeringa S. G. , Lewandowski-Romps L. , Millikan-Bell A. M. , Naifeh J. A. , Nock M. K. , Petukhova M. V. , Sampson N. A. , Schoenbaum M. , Stein M. B. , Ursano R. J. , Wessely S. , Zaslavsky A. M. , Kessler R. C.
Published: February 2014

Background

The US Army suicide rate has increased sharply in recent years. Identifying significant predictors of Army suicides in Army and Department of Defense (DoD) administrative records might help focus prevention efforts and guide intervention content. Previous studies of administrative data, although documenting significant predictors, were based on limited samples and models. A career history perspective is used here to develop more textured models.

Method

The analysis was carried out as part of the Historical Administrative Data Study (HADS) of the Army Study to Assess Risk and Resilience in Servicemembers (Army STARRS). De-identified data were combined across numerous Army and DoD administrative data systems for all Regular Army soldiers on active duty in 2004–2009. Multivariate associations of sociodemographics and Army career variables with suicide were examined in subgroups defined by time in service, rank and deployment history.

Results

Several novel results were found that could have intervention implications. The most notable of these were significantly elevated suicide rates (69.6–80.0 suicides per 100 000 person-years compared with 18.5 suicides per 100 000 person-years in the total Army) among enlisted soldiers deployed either during their first year of service or with less than expected (based on time in service) junior enlisted rank; a substantially greater rise in suicide among women than men during deployment; and a protective effect of marriage against suicide only during deployment.

Conclusions

A career history approach produces several actionable insights missed in less textured analyses of administrative data predictors. Expansion of analyses to a richer set of predictors might help refine understanding of intervention implications.
Green hydrothermal synthesis of CeO2 NWs–reduced graphene oxide hybrid with enhanced photocatalytic activity
Authors: Huang K. , Lei M. , Wang Y.J. , Liang C. , Ye C.X. , Zhao X.S. , Li Y.F. , Zhang R. , Fan D.Y. , Wang Y.G.
Published: February 2014

In this study, CeO2 nanowires–reduced graphene oxide hybrids (CeO2 NWs–RGO) were synthesized by a green hydrothermal method using CeO2 NWs and graphene oxide (GO) as raw materials. During the process of reduction of GO, hydrothermal condition with supercritical water provides thermal and chemical factors to synthesize RGO. The photocatalytic experimental results show that the CeO2 NWs–RGO hybrids exhibit enhanced photocatalytic activity for degradation of Rhodamine B (RhB) under UV-light irradiation. It is found that the degree of photocatalytic activity enhancement strongly depends on the mass ratio of RGO in the hybrids, and the remarkable photocatalytic activity is 20 times that of pristine CeO2 NWs when the loading amount of RGO is 8.0 wt%. The enhancement of photocatalytic activity can be attributed to the excellently elevated absorption ability for the dye through π–π conjugation as well as the effective inhibition of the recombination of photogenerated electrons because of the electronic interaction between CeO2 NWs and RGO sheets.
Facing Digital Realities: Where Media Do Not Mix
Authors: Trippett David
Published: February 2014

Wagner’s vaunted model of artistic synthesis persists in scholarly assessments of his work. But at its centre, the composer argued that the media of voice and orchestra do not mix: they retain their identities as separate channels of sound that can neither duplicate nor substitute for one another. Taking as a starting point Wagner’s claims for the non-adaptability of media, this article addresses the adaptation of Wagner’s music to the modern digital technologies of HD cinema and video game. Drawing on a wide circle of writers, from Schiller and Žižek to Bakhtin, Augé, Baudrillard and second-generation media theorists, it interrogates the concept of ‘reality’ within live acoustic performance, both historically, as a discursive concept, and technologically, via the sensory realism of digital simulcasting and telepresence. The philosophical opposition of appearance and reality fails when reality is defined by the intimate simulation of a sensory event as it is registered on the body. And by contrasting the traditions of high fidelity in (classical) sound recording with that of rendering sound in cinema, I suggest ways in which unmixable media appear to have an afterlife in modern technologies. This raises questions – in a post-Benjamin, post-McLuhan context – about our definition of ‘liveness’, the concept of authenticity within mediatised and acoustic sounds, and our vulnerability to the technological effects of media.
Platelet-rich plasma for patent ductus arteriosus: an orthopaedic surgeon’s perspective
Authors: Ali Engür Mehmet , Engür Defne
Published: February 2014

Although closure of ductus arteriosus requires multiple intriguing cell signalling pathways, current treatment options merely act through cyclooxygenase inhibition. Expectedly, medical management of ductus arteriosus is quite far away from optimum and there is an ongoing debate on its efficiency and safety. The ideal therapeutic agent for patent ductus arteriosus should target vascular remodelling and support the arrested molecular steps that should completely eventuate during anatomical closure.

Platelet-rich plasma injection, which has been used as a treatment alternative for many musculoskeletal conditions, can be a promising solution in this context by compensating the relative platelet dysfunction in preterms and providing a convenient microenvironment for proper cellular communication for ductal closure.

First, by inducing hyaluronan synthase, platelet-rich plasma can induce mount formation in the intima, which is the significant defective milestone in preterms. Second, by providing platelet-derived growth factor, it can further stimulate platelet agregation and occlusion of the lumen. Finally, it can provide an increment in local vascular endothelial growth factor and transforming growth factor-β levels, which cannot be achieved because of insufficient intramural hypoxia. Migration of the vascular smooth muscles would further be triggered by transforming growth factor-β and vascular endothelial growth factor, aiding a major contribution to ductal closure.

Above and beyond all other considerations, opportunity of local application would render maximum effectiveness and minimum side effects.
ANIMATING HOUSEHOLD GODS: VALUE, TOTEMS, AND KINSHIP IN VICTORIAN ANTHROPOLOGY AND DICKENS'SDOMBEY AND SON
Authors: Rajan Supritha
Published: February 2014

At the heart of Dickens'sDombey and Son(1846–48) is a woman who is both the central problem that the narrative seeks to manage and its solution to that problem. Florence's position as heiress to Dombey and Son enables her entry into the marketplace as an independently wealthy woman who disrupts the patriarchal transmission of property and money.Dombey and Sondiverts attention from Florence's position as heiress by providing a sentimental lesson on the economic importance of the domestic woman, who grounds intrinsic value and is essential to the reproduction of the patriarchal family and economy. Dombey's domestic and financial failures, the novel would have us believe, stem from his initial devaluation of Florence and overvaluation of Paul. Hence, at the novel's close, Dombey learns that the foundation of the family and firm is not a son but “a Daughter after all.” Dickens thus presents Florence's intrinsic value and inalienability as the resolution to the very problem of alienability and unstable values that her position as heiress encodes. Yet this lesson regarding Florence's value conceals the novel's central anxiety, what Robert Clark refers to as “the arbitrary taboo on women's participation in the economic order” (73). If the novel accords insubstitutable value to the domestic woman as the keystone of the family and economy, it does so to dramatize the threat posed to patriarchal structures of kinship, property, and capitalist expansion if all women were to enter the marketplace and become, in a sense, heiresses.
Supplementary private pensions and saving: evidence from Spain
Authors: ANTÓN JOSÉ-IGNACIO , DE BUSTILLO RAFAEL MUÑOZ , FERNÁNDEZ-MACÍAS ENRIQUE
Published: February 2014

This paper analyzes the effect of private supplementary pensions (and the tax reliefs that aim to stimulate such plans) on national saving in Spain. It tries to test the alleged positive effects of private pension plans on savings. Using a longitudinal dataset and fixed-effects methods, we find that tax-favored contributions to a pension fund are not associated with a lower consumption level, which implies that this policy does not increase national saving. The empirical results on the impact of contributions on private household wealth are less clear.
Was ist Achtsamkeit? Herkunft, Praxis und Konzeption
Authors: Schmidt Stefan
Published: February 2014

Inhaltsübersicht: Ausgehend von der momentanen Popularität wird versucht den Begriff der Achtsamkeit sowohl in seinen historischen Wurzeln als auch in seiner aktuellen Verwendung zu fassen. Es zeigt sich zunächst, dass der Erfahrungsbezug einer Praxis der Achtsamkeit im Widerspruch zu einer statischen wissenschaftlichen Definition eines Konzeptes der Achtsamkeit steht. Somit zeigt sich die Achtsamkeit auch je nach Kontext in unterschiedlichen Spielarten. Bestimmend ist dabei die Motivation mit der die Achtsamkeit praktiziert wird. Im frühen Buddhismus, in dem die Achtsamkeit das erste Mal explizit auftaucht, ist die Motivation auf spirituelles Wachstum und Selbsttransformation gerichtet. In unserer modernen westlichen Gesellschaft finden sich neben den spirituellen auch säkulare Motive. Achtsamkeit wird in den unterschiedlichsten Feldern mit den unterschiedlichsten Ausgangsmotivationen praktiziert. Neben dem Wunsch nach Entspannung, Wohlbefinden und Selbstexploration finden sich auch Anwendungsfelder in klinischen und auch pädagogischen Bereichen. Spezifisch in der Suchttherapie bietet sich ein strukturiertes achtsamkeitsbasiertes Programm zur Rückfallprophylaxe an. Schlussfolgerung: Die Popularität des Achtsamkeitskonzeptes lässt sich als eine kollektive Selbstregulation unserer Kultur auf eine zunehmende Funktionalisierung und Beschleunigung interpretieren.
Die neuronale Basis von Meditation und Achtsamkeit
Authors: Esch Tobias
Published: February 2014

Fragestellung: Beschreibung neurobiologischer Effekte und Wirkmechanismen der Achtsamkeit bzw. Achtsamkeitsmeditation (current state). Methodik: Umfassende, selektive Literaturrecherche in internationalen und nationalen Datenbanken. Ergebnisse: Neurobiologische Effekte von Meditation und Achtsamkeit lassen sich im Gehirn im Bereich funktioneller, aber auch struktureller Veränderungen von grauer und weißer Substanz nachweisen, insbesondere in Arealen, die mit Aufmerksamkeit und Gedächtnis, Interozeption und sensorischer Verarbeitung sowie mit der Selbst- und Autoregulation (inkl. der Kontrolle von Stress und Emotionen) zusammenhängen. Die neuronalen Wirkmechanismen der Achtsamkeit lassen sich systematisch daher in vier Bereiche einteilen: Aufmerksamkeitsregulation, Körpergewahrsein, Emotionsregulation und Selbstwahrnehmung. Auf neuroendokriner Ebene ist eine Beteiligung von Dopamin und Melatonin (Erhöhung), Serotonin (Modulation) sowie von Cortisol und Norepinephrin (Erniedrigung) nachgewiesen. Schlussfolgerungen: Die Befunde sind für die Medizin und das Gesundheitswesen interessant, auch vor dem Hintergrund von therapeutischen Verhaltens- und Lebensstilmodifikationen, im Stressmanagement und insbesondere in der Suchtbehandlung.
Praktische Anwendung von Achtsamkeit in der Suchttherapie am Beispiel des MBRP Programms und der DBT-Sucht
Authors: Mundle Götz , Bowen Sarah , Heinz Andreas , Kienast Thorsten
Published: February 2014

Hintergrund: „Achtsamkeitsbasierte Rückfallprävention bei Substanzabhängigkeit (MBRP) und das suchtspezifische Modul „Umgang mit Sucht“ der Dialektisch Behavioralen Therapie (DBT-S) integrieren Achtsamkeit als zentrale Fertigkeit und Grundhaltung in ihr Konzept der Behandlung von Abhängigkeitserkrankten. Innere und äußere Achtsamkeit beschreiben hier das konzentrierte, nicht bewertende Wahrnehmen oder Beschreiben des Umfeldes oder inneren Befindens einer Person. Sie ermöglicht dem Anwender durch ihre Bewertungsneutralität neue Wege aus der Sucht zu finden, Frühwarnzeichen zu erkennen und neue Lösungen für alte Probleme zu entdecken. Während Substanzkonsum Erleben reduziert, erhöht die Anwendung von Achtsamkeit den Erlebnishorizont und bietet eine Chance auf einen erweiterten Blick auf das eigene Leben. Achtsamkeit ermöglicht somit einen neuen Umgang mit Suchtmittelverlangen. Fragestellung: In diesem Artikel werden MBSR und DBT-S vorgestellt.
Der Verlauf der Diamorphinbehandlung unter den Bedingungen der gesundheitlichen Regelversorgung – eine 12-Monats-Analyse
Authors: Verthein Uwe , Kuhn Silke , Schäfer Ingo
Published: February 2014

Hintergrund: Nachdem das bundesdeutsche Modellprojekt zur heroingestützten Behandlung 2007 auslief, wurde vom Zentrum für Interdisziplinäre Suchtforschung der Universität Hamburg (ZIS) ein Qualitätssicherungsprojekt aufgelegt, durch das die regelmäßige Dokumentation von Behandlungsstandards und Effekten weiterhin sicher gestellt werden konnte. Fragestellung: Im Mittelpunkt der Auswertung steht die Beschreibung von aktuellem Status und 1-Jahres-Behandlungsverlauf der nach der Studie neu in die Diamorphinbehandlung aufgenommenen Patienten. Der Behandlungsverlauf kann denen der Studienpatienten gegenüber gestellt werden. Methodik: Von den behandelnden Ärzten wurde zu Beginn und im 6-Monats-Abstand pro Patient anhand eines standardisierten Erhebungsbogens der Aufnahmestatus sowie der Behandlungsverlauf dokumentiert. Für die Beschreibung des aktuellen Zustands wurde die letzte Dokumentation in 2011 herangezogen, der Verlauf wurde anhand eines Vergleichs von Aufnahme- und 1-Jahres-Dokumentation analysiert. Ergebnisse: Über 341 Diamorphinpatienten liegen in 2011 Informationen zum aktuellen Zustand vor, davon sind 205 (60,1 %) nach dem Modellprojekt aufgenommen worden. Die Mehrheit kommt für 2 Vergaben am Tag. Die mittlere Tagesdosis Diamorphin der seit durchschnittlich mehr als 8 Jahre behandelten Modellprojektpatienten beträgt 358 mg, die der seit durchschnittlich eineinhalb Jahren behandelten Neuaufnahmen 432 mg. 3,6 % sind HIV-positiv, 75,0 % mit Hepatitis C infiziert. Bei einem Viertel wurden depressive Störungen diagnostiziert. Die Mehrheit lebt in stabilen Wohnverhältnissen, ein Viertel hat eine regelmäßige Arbeit oder Jobs. Justitielle Delikte werden von 6,7 % der Diamorphinpatienten berichtet. 5,1 % konsumierten innerhalb der letzten 30 Tage noch Straßenheroin, 22,4 % Kokain. Hinsichtlich der Veränderungen innerhalb des ersten Behandlungsjahres zeigen sich in den Bereichen Gesundheit, soziale Situation und Drogenkonsum deutliche und statistisch signifikante Verbesserungen. Schlussfolgerung: Die Diamorphinbehandlung in Deutschland wird auch unter den Bedingungen der Regelversorgung erfolgreich durchgeführt. Die aktuelle Situation der sich seit vielen Jahren in Behandlung befindlichen Modellprojektpatienten stellt sich stabiler dar, was darauf hindeutet, dass weitreichende Veränderungen viel Zeit benötigen. Die positiven Wirkungen nach einem Jahr Diamorphinbehandlung sind denen aus dem Bundesmodellprojekt vergleichbar.