bluuebunny/crossref_metadata_2025 huggingface dataset:
Toward a New Predictive Model of Student Retention in Higher Education
Authors: Kerby Molly B.
Published: April 2015

Theoretical models designed to predict whether students will persist or not have been valuable tools for retention efforts relative to the creation of services in academic and student affairs. Some of the early models attempted to explain and measure factors in the college dropout process. For example, in his seminal work, Tinto defined retention as a longitudinal process incorporating both the academic potential of the student and institutional social systems, thus creating a directional model based on continual variance in social commitments that influence academic performance. Others expanded the earlier theoretical models to test the predictive capabilities of these models using logistical regression and structural equation modeling to project college retention rates. As public sectors push for performance-based accountability in federal and state agencies, higher education funding becomes directly linked to academic performance. Critics of performance-based accountability in higher education contend that these funding structures undermine the mission of the university system and negatively impact retention in higher education. As Astin suggested, the structure of the American college system is a great deal more complex than the elementary concept of supply side economics. Additionally, due to globalization and aggressive progress in information technology, a shift from labor-intensive, information-age economies to a knowledge-based economy has created competing forces between academic and social integration in retention efforts. As intensity increases toward developing global knowledge-based economies, latent functions providing the framework for the process of learning (social integration, social control, and social change) give way to the manifest functions that reduce education to a process in which individuals merely collect information for future dissemination. Decades of research indicate that the role of education is not merely transmission of information. Higher education prompts progressive social changes that are augmented not only by dissemination of knowledge but also by the interconnectedness of the college experience, socialization process, and discovery of self in terms of place. A new conceptual model, grounded in classical sociological theory, is necessary to accommodate a knowledge-based economy. Universities must incorporate protective factors that generate a resilient environment for student learning, adaptation, and retention. Expanding the retention models of Spady and Tinto enhances the predictability of conceptual models for a new paradigm that fully recognizes the relationships among external factors (national and educational climate), internal factors (institutional culture and climate), and adaptive factors (sense of place) that effect voluntary dropout decisions in higher education.
Does Imaging Technology Cause Cancer? Debunking the Linear No-Threshold Model of Radiation Carcinogenesis
Authors: Siegel Jeffry A. , Welsh James S.
Published: April 2015

In the past several years, there has been a great deal of attention from the popular media focusing on the alleged carcinogenicity of low-dose radiation exposures received by patients undergoing medical imaging studies such as X-rays, computed tomography scans, and nuclear medicine scintigraphy. The media has based its reporting on the plethora of articles published in the scientific literature that claim that there is “no safe dose” of ionizing radiation, while essentially ignoring all the literature demonstrating the opposite point of view. But this reported “scientific” literature in turn bases its estimates of cancer induction on the linear no-threshold hypothesis of radiation carcinogenesis. The use of the linear no-threshold model has yielded hundreds of articles, all of which predict a definite carcinogenic effect of any dose of radiation, regardless of how small. Therefore, hospitals and professional societies have begun campaigns and policies aiming to reduce the use of certain medical imaging studies based on perceived risk:benefit ratio assumptions. However, as they are essentially all based on the linear no-threshold model of radiation carcinogenesis, the risk:benefit ratio models used to calculate the hazards of radiological imaging studies may be grossly inaccurate if the linear no-threshold hypothesis is wrong. Here, we review the myriad inadequacies of the linear no-threshold model and cast doubt on the various studies based on this overly simplistic model.
Clinical, Electroencephalographic, and Neuroradiological Outcome Predictors in Acute Nonhypoxic Encephalopathy
Authors: Sutter Raoul , Kaplan Peter W.
Published: April 2015

Marked impairment of consciousness, brain lesion on neuroimaging, and nonreactive electroencephalographic (EEG) background activity are established outcome predictors in patients with hypoxic encephalopathy. In this observational cohort study, we aimed to assess the predictive value of clinical, neuroimaging and EEG characteristics for outcome in different types of acute nonhypoxic encephalopathic patients. All adult intensive care unit patients from a tertiary academic medical care center with clinical and EEG evidence of acute nonhypoxic encephalopathy were included from 2004 to 2012. Clinical data, neuroimaging studies, EEG characteristics, and outcome were assessed. In-hospital death was the main outcome. Median age of 262 patients was 65 years (range 18-98 years). Mortality was 12.6%. In Poisson regression analyses, older age ( P = .02), intracranial hemorrhage ( P = .008), coma ( P = .012), and nonreactive EEG background activity ( P < .0001) were independently associated with death with nonreactive EEG being the strongest predictor (relative risk 3.74; 95% confidence interval 2.02-6.91). Subgroup analysis revealed no significant effect modification for the predictive value of nonreactive EEG by the presence or absence of coma and different types of acute brain lesions. In conclusion, this study identifies and quantifies the independent predictive value of older age, intracranial hemorrhage, coma, and nonreactive EEG for death, in patients with different types of acute nonhypoxic encephalopathy. These results add further credence to the limited body of evidence that EEG provides important prognostic information in different types of acute encephalopathy not related to hypoxic brain injury. Further studies are warranted to analyze the robustness of this predictor in larger subpopulations with specific etiologies of acute nonhypoxic encephalopathies.
Review: Quality of life in lower limb peripheral vascular surgery
Authors: Donker JMW , de Vries J , Ho GH , Gonçalves F Bastos , Hoeks SE , Verhagen HJM , van der Laan L
Published: April 2015

Purpose

Vascular intervention studies generally consider patency and limb salvage as primary outcomes. However, quality of life is increasingly considered an important patient-oriented outcome measurement of vascular interventions. Existing literature was analyzed to determine the effect of different treatments on quality of life for patients suffering from either claudication or critical limb ischemia.

Basic methods

A review of the literature was undertaken in the Medline library. A search was performed on quality of life in peripheral arterial disease. Results were stratified according to treatment groups.

Principal findings

Twenty-one articles described quality of life in approximately 4600 patients suffering from peripheral arterial disease. Invasive treatment generally results in better quality of life scores (at a maximum of 2 years of follow-up), compared with non-invasive treatment. In patients with critical limb ischemia, successful revascularization improves quality of life scores. Only one study reported long-term results.

Conclusions

Increase in quality of life scores can be found for any intervention performed for peripheral arterial disease. However, there is scarce information on long-term quality of life after vascular intervention.
Should the governments of ‘developed’ countries be held responsible for equalizing the indigenous health gap?
Authors: Abdolhosseini Parirash , Bonner Chantel , Montano Alexandra , Young Yves-Yvette , Wadsworth Daniel , Williams Michelle , Stoner Lee
Published: April 2015

Across the globe there is significant variation between and within indigenous populations in terms of world view, culture, and socio-political forces. However, many indigenous groups do share a striking commonality: greater rates of non-communicable diseases and shorter life expectancies than non-indigenous compatriots. Notably, this health gap persists for ‘developed’ countries, including Australia, Canada, New Zealand and the United States. The question of who is responsible for equalizing the gap is complicated. Using Australia as an exemplar context, this commentary will present arguments ‘for’ and ‘against’ the governments of developed nations being held liable for closing the indigenous health gap. We will discuss the history and nature of the health gap, actions needed to ‘close the gap’, and which party has the necessary resources to do so.
Comparison of 22G reverse‐beveled versus standard needle for endoscopic ultrasound‐guided sampling of solid pancreatic lesions
Authors: Alatawi Abdullah , Beuvon Frédéric , Grabar Sophie , Leblanc Sarah , Chaussade Stanislas , Terris Benoit , Barret Maximilien , Prat Frédéric
Published: April 2015

Objectives

Endoscopic ultrasound‐guided fine‐needle aspiration (EUS‐FNA) using standard needles has a high diagnostic value in the evaluation of solid pancreatic masses. Fenestrated needles have been developed to improve the quality of EUS‐guided tissue sampling by providing core biopsies (FNB).

Methods

Patients with solid pancreatic masses of >2 cm were prospectively included in our study and randomized to receive EUS sampling, using either a standard 22G FNA or a 22G Procore® FNB needle. The main study endpoint was the number of needle passes required to obtain a diagnosis in more than 90% of cases.

Results

We included 100 patients (male = 63, female = 37; mean age = 68.4 years) in our study. We found that 88% of the lesions were malignant, with a mean size of 32 mm. A sample adequate for diagnosis was obtained in more than 90% of cases after the second needle pass in the FNB group, versus the third needle pass in the FNA group. Slide cellularity and presence of tissue microfragments were significantly higher in the FNB group. Sensitivity for the diagnosis of malignancy was 88.4% versus 97.8% for the EUS‐FNA and EUS‐FNB group, respectively, while specificity for both techniques was 100%. No complications were recorded.

Conclusions

Although the accuracy of both needle types for proving malignancy was similar, a lower number of passes was required with the FNB needles to achieve the same contributive sample rate as with the FNA needles. FNB also improved the histopathological quality of specimens, suggesting an overall superiority of FNB sampling.
Are the definitions for chronic diarrhoea adequate? Evaluation of two different definitions in patients with chronic diarrhoea
Authors: Stotzer Per-Ove , Abrahamsson Hasse , Bajor Antal , Kilander Anders , Sadik Riadh , Sjövall Henrik , Simrén Magnus
Published: April 2015

Background

The classical definition of chronic diarrhoea is ≥3 defecations/day, with a stool weight of more than 200 g and duration of ≥4 weeks. However, with this definition many patients with substantial symptoms and pathology will be excluded from further investigations. As a consequence other definitions have been proposed, mainly based on evaluation of the stool form.

Objective

To evaluate the accuracy of the classic criteria for diarrhoea in comparison with a definition based on stool consistency, using the Bristol Stool Form Scale.

Methods

All patients were investigated with laboratory tests, upper and lower gastrointestinal endoscopy with biopsies, and SeHCAT test. They were asked to complete a diary recording stool frequency and consistency during a week, as well as other gastrointestinal symptoms (pain, bloating and gas).

Results

One hundred and thirty‐nine subjects were eligible for analysis. Ninety‐one had an organic cause of diarrhoea. Fifty‐three patients had ≥3 loose stools/day, whereas 86 reported <3 stools/day. Ninety had a median stool consistency that was mushy or loose and 49 had harder stools. A higher proportion of subjects with an organic cause of their diarrhoea compared with subjects with a functional bowel disorder had ≥3 loose stools/day, 43/91 (47%) vs. 10/48 (21%) (p  < 0.01). Similarly, more subjects with an organic cause of their diarrhoea versus patients with a functional bowel disorder had a median stool consistency that was mushy or watery, 73/91 (80%) vs. 17/48 (35%), p  < 0.0001. When diarrhoea was defined according to stool form, more patients were classified correctly as having a functional disorder or organic disorder, compared with the classical definition (p  < 0.05).

Conclusion

Loose stools defined according to the Bristol Stool Form scale seem to be the best predictor of having an organic cause of the diarrhoea.
Translating Ἀσθενέω in James 5 in Light of the Prophetic LXX
Authors: Bowden Andrew
Published: April 2015

This article argues that the LXX prophetic material should be considered when translating ἀσθενέω in James 5.14. This context implies that James, like the prophets, is offering restoration to those who have fallen into sin. In order to understand the role of the LXX prophetic material in James, a recent essay by Karen Jobes is highlighted, followed by further analysis of James’s allusion to the LXX and of the context and thought flow of 5.13-18. Although it is increasingly recognized that the prophetic material was an important source for James, its possible influence on the meaning of ἀσθενέω in 5.14 has been overlooked. After arguing that James addresses the spiritually fallen, the article examines several details of the paragraph in order to see how this conclusion relates to the immediate context.
Translation as Performance and Engagement: Performing Philemon from a Modern Caribbean Perspective
Authors: Winedt Marlon
Published: April 2015

This introductory article addresses the use of performance criticism in the translation of Philemon as a means of critically engaging a modern Caribbean audience. The aim is to elicit a hermeneutical appropriation, which faces, in one way or the other, the polemic of condoned New Testament slavery, the reality of the Atlantic slave trade, and the liberating message of the gospel, which in the concrete case of Philemon is expressed rather subtly. The point of departure is that oral performance played a key role in the composition and dissemination of the original Scripture texts. This, combined with the salient fact that orality plays a key role in Creole language cultures, provides a fecund terrain for the translator. As an illustration, an integral translation for performance in Papiamentu, a Caribbean Creole, is juxtaposed with a provocative fictional response by the historical character of Tula, the Curaçaoan revolt leader of 1795.
Do (weak) upper houses matter for cabinet formation? A replication and correction
Authors: Eppner Sebastian , Ganghof Steffen
Published: April 2015

Do upper houses matter for cabinet formation? If so, does it make a difference how powerful they are? The most sophisticated study to give clear answers to these questions is still that of Druckman, Martin and Thies (2005), which argues that upper houses influence cabinet formation, regardless of their formal powers. We dispute these answers theoretically and empirically. Since adjusting cabinet formation to second chamber composition is not necessary and can be costly, we should expect that if upper houses matter at all, their formal powers should matter too. Replication shows that the empirical results are driven exclusively by two countries with weak upper houses, one of which (Ireland) is miscoded. If this case is recoded there is no statistically or substantially significant effect of upper houses, regardless of their power. We conclude that the two questions cannot yet be answered: we need more research based on broader samples in order to assess whether upper houses matter for cabinet formation and whether their formal powers make a difference.
Circulating cell membrane microparticles transfer heme to endothelial cells and trigger vasoocclusions in sickle cell disease
Authors: Camus Stéphane M. , De Moraes João A. , Bonnin Philippe , Abbyad Paul , Le Jeune Sylvain , Lionnet François , Loufrani Laurent , Grimaud Linda , Lambry Jean-Christophe , Charue Dominique , Kiger Laurent , Renard Jean-Marie , Larroque Claire , Le Clésiau Hervé , Tedgui Alain , Bruneval Patrick , Barja-Fidalgo Christina , Alexandrou Antigoni , Tharaux Pierre-Louis , Boulanger Chantal M. , Blanc-Brude Olivier P.
Published: April 2015

Key Points

A significant fraction of cell-free heme in plasma is contained in circulating erythrocyte MPs, particularly during hemolysis. Heme-laden MPs can transfer heme to vascular endothelium and mediate oxidative stress, vascular dysfunction, and vasoocclusions.
The tumor virus landscape of AIDS-related lymphomas
Authors: Arvey Aaron , Ojesina Akinyemi I. , Pedamallu Chandra Sekhar , Ballon Gianna , Jung Joonil , Duke Fujiko , Leoncini Lorenzo , De Falco Giulia , Bressman Eric , Tam Wayne , Chadburn Amy , Meyerson Matthew , Cesarman Ethel
Published: April 2015

Key Points

We evaluated a cohort of ARL samples for known and novel tumor viruses, revealing the oncogenic herpesvirus EBV as the sole detected infectious agent. Heterogeneous viral gene expression suggests that variable host immunosurveillance of EBV latency may influence lymphomagenesis.
How I treat Langerhans cell histiocytosis
Authors: Allen Carl E. , Ladisch Stephan , McClain Kenneth L.
Published: April 2015

“Langerhans cell histiocytosis” (LCH) describes a spectrum of clinical presentations ranging from a single bone lesion or trivial skin rash to an explosive disseminated disease. Regardless of clinical severity, LCH lesions share the common histology of CD1a+/CD207+ dendritic cells with characteristic morphology among an inflammatory infiltrate. Despite historical uncertainty defining LCH as inflammatory vs neoplastic and incomplete understanding of mechanisms of pathogenesis, clinical outcomes have improved markedly over the past decades through cooperative randomized clinical trials based on empiric therapeutic strategies. Significant advances include recognition of high- and low-risk clinical groups defined by hematopoietic and/or hepatic involvement, and of the importance of optimal intensity and of duration of chemotherapy. Nevertheless, mortality of high-risk patients, disease recurrence, lack of robustly tested salvage strategies, and significant disease morbidity of both high- and low-risk patients remain challenges. Recent discovery of recurrent somatic mutations in mitogen-activated protein kinase pathway genes at critical stages of myeloid hematopoietic differentiation in LCH patients supports redefinition of the disease as a myeloproliferative disorder and provides opportunities to develop novel approaches to diagnosis and therapy.
Protein-bound drugs are prone to sequestration in the extracorporeal membrane oxygenation circuit: results from an ex vivo study
Authors: Shekar Kiran , Roberts Jason A , Mcdonald Charles I , Ghassabian Sussan , Anstey Chris , Wallis Steven C , Mullany Daniel V , Fung Yoke L , Fraser John F
Published: April 2015

Introduction

Vital drugs may be degraded or sequestered in extracorporeal membrane oxygenation (ECMO) circuits, with lipophilic drugs considered to be particularly vulnerable. However, the circuit effects on protein-bound drugs have not been fully elucidated. The aim of this experimental study was to investigate the influence of plasma protein binding on drug disposition inex vivoECMO circuits.

Methods

Four identical ECMO circuits comprising centrifugal pumps and polymethylpentene oxygenators and were used. The circuits were primed with crystalloid, albumin and fresh human whole blood and maintained at a physiological pH and temperature for 24 hours. After baseline sampling, known quantities of study drugs (ceftriaxone, ciprofloxacin, linezolid, fluconazole, caspofungin and thiopentone) were injected into the circuit to achieve therapeutic concentrations. Equivalent doses of these drugs were also injected into four polypropylene jars containing fresh human whole blood for drug stability testing. Serial blood samples were collected from the controls and the ECMO circuits over 24 hours, and the concentrations of the study drugs were quantified using validated chromatographic assays. A regression model was constructed to examine the relationship between circuit drug recovery as the dependent variable and protein binding and partition coefficient (a measure of lipophilicity) as explanatory variables.

Results

Four hundred eighty samples were analysed. There was no significant loss of any study drugs in the controls over 24 hours. The average drug recoveries from the ECMO circuits at 24 hours were as follows: ciprofloxacin 96%, linezolid 91%, fluconazole 91%, ceftriaxone 80%, caspofungin 56% and thiopentone 12%. There was a significant reduction of ceftriaxone (P= 0.01), caspofungin (P= 0.01) and thiopentone (P= 0.008) concentrations in the ECMO circuit at 24 hours. Both protein binding and partition coefficient were highly significant, with the model possessing a high coefficient of determination (R2 = 0.88,P<0.001).

Conclusions

Recovery of the highly protein-bound drugs ceftriaxone, caspofungin and thiopentone was significantly lower in the ECMO circuits at 24 hours. For drugs with similar lipophilicity, the extent of protein binding may determine circuit drug loss. Future clinical population pharmacokinetic studies should initially be focused on drugs with greater lipophilicity and protein binding, and therapeutic drug monitoring should be strongly considered with the use of such drugs.
Methotrexate: should it still be considered for chronic calcium pyrophosphate crystal disease?
Authors: Pascual Eliseo , Andrés Mariano , Sivera Francisca
Published: April 2015

Chronic calcium pyrophosphate crystal arthritis is a clinical consequence of the formation and deposition of these crystals in joints and can result in persistent arthritis. Curative treatment would require the removal of crystals from joints and tissues, but to date all agents tested have proven ineffective. Management of the inflammatory manifestations of chronic calcium pyrophosphate disease includes glucocorticoids, non-steroidal anti-inflammatory drugs, or colchicine, and responses are usually satisfactory. However, in some patients, the response to these agents is poor or they are contraindicated. Methotrexate had been reported as a promising option in small case series; however, in a recent issue of Arthritis Research & Therapy, a clinical trial failed to confirm the anticipated benefits. Here, we discuss some issues that might have influenced the results of the study, before deciding to abandon methotrexate as a therapeutic option for patients with chronic calcium pyrophosphate arthritis.
Effect of long-term supplementation with folic acid and B
vitamins on risk of depression in older women
Authors: Okereke Olivia I. , Cook Nancy R. , Albert Christine M. , Van Denburgh Martin , Buring Julie E. , Manson JoAnn E.
Published: April 2015

Background

Homocysteine-lowering nutrients may have preventive/ameliorative roles in
depression.

Aims

To test whether long-term B-vitamin/folate supplementation reduces
depression risk.

Method

Participants were 4331 women (mean age 63.6 years), without prior
depression, from the Women's Antioxidant and Folic Acid Cardiovascular
Study – a randomised controlled trial of cardiovascular disease
prevention among 5442 women. Participants were randomly assigned to
receive a combination of folic acid (2.5mg/d), vitamin B6
(50mg/d) and vitamin B12 (1 mg/d) or a matching placebo.
Average treatment duration was 7 years. The outcome was incident
depression, defined as self-reported physician/clinician-diagnosed
depression or clinically significant depressive symptoms.

Results

There were 524 incident cases. There was no difference between active
v. placebo groups in depression risk (adjusted
relative risk 1.02, 95% CI 0.86–1.21, P = 0.81), despite
significant homocysteine level reduction.

Conclusions

Long-term, high-dose, daily supplementation with folic acid and vitamins
B6 and B12 did not reduce overall depression
risk in mid-life and older women.
Severn School of Psychiatry education fellowships: a new way to promote educational practice and research
Authors: Macpherson Rob , Arulanandam Sherlie , Undrill Guy , Atkinson Simon , Arnott Steve , Hughes Sian , Toogood Hannah , Scheeres Karl , Matone Luciana
Published: April 2015

This paper describes a model of training in leadership and project management skills for advanced trainees, using educational projects within the Severn School of Psychiatry. Fellowships lasting 1 year have been developed to enable trainees, working with a senior consultant trainer associated with the School of Psychiatry, to support important new educational initiatives. Linkage with the local university training and learning for health professionals research module has provided academic support for the trainees and the projects. Four examples for the first year of the programme are described and feedback from structured interviews with participants is presented. The development of the fellowships appears to have had wider benefits, in developing educational faculty in the School of Psychiatry and the trainees involved have had opportunities to extend their project management and leadership skills. The fellowship programme is continuing to develop, based on feedback from its first successful year.
Recognition of the neurobiological insults imposed by complex trauma and the implications for psychotherapeutic interventions
Authors: Corrigan Frank M. , Hull Alastair M.
Published: April 2015

Considerable research has been conducted on particular approaches to the psychotherapy of post-traumatic stress disorder (PTSD). However, the evidence indicates that modalities tested in randomised controlled trials (RCTs) are far from 100% applicable and effective and the RCT model itself is inadequate for evaluating treatments of conditions with complex presentations and frequently multiple comorbidities. Evidence at levels 2 and 3 cannot be ignored. Expert-led interventions consistent with the emerging understanding of affective neuroscience are needed and not the unthinking application of a dominant therapeutic paradigm with evidence for PTSD but not complex PTSD. The over-optimistic claims for the effectiveness of cognitive–behavioural therapy (CBT) and misrepresentation of other approaches do not best serve a group of patients greatly in need of help; excluding individuals with such disorders as untreatable or treatment-resistant when viable alternatives exist is not acceptable.
Bisphenol-A Treatment During Pregnancy in Mice: A New Window of Susceptibility for the Development of Diabetes in Mothers Later in Life
Authors: Alonso-Magdalena Paloma , García-Arévalo Marta , Quesada Iván , Nadal Ángel
Published: April 2015

Evidence now exists supporting the hypothesis that endocrine-disrupting chemicals (EDCs) can harmfully impact glucose metabolism. Thus, EDCs are beginning to be considered important contributors to the increased incidence of diabetes, obesity, or both. The possible effect of exposure to EDCs during pregnancy on glucose homeostasis in mothers later in life is presently unknown. Here we show that several months after delivery, mothers treated with the widespread EDC bisphenol-A (BPA) during gestation, at environmentally relevant doses, exhibit profound glucose intolerance and altered insulin sensitivity as well as increased body weight. These mice presented a decreased insulin secretion both in vivo and in vitro together with reduced pancreatic β-cell mass. The proliferation capacity was decreased in association with a diminished expression of the cell cycle activators: cyclin D2 and cyclin-dependent kinase-4. In addition, the rate of β-cells apoptosis was increased as well as the expression of the cell cycle inhibitors p16 and p53. Conversely, no effects on glucose metabolism or insulin sensitivity were observed when female nonpregnant mice were treated with BPA at the same doses. Taken together, these findings reveal that BPA exposure during gestation has harmful long-term implications in glucose metabolism for the mother. This finding highlights a new window of susceptibility for EDC exposure that may be important for the development of type 2 diabetes.
Money, Debt, and the Business of “Free Stuff”
Authors: Allon Fiona
Published: April 2015

The overexposed, overindebted neoliberal consumer has become one of the most representative figures of financial capitalism. But both the commonsense claim that all money is essentially debt and its converse, that all debt is now money that can beget more money, foreclose analytical investigation of contemporary shifts in monetization and the specificity of creditor-debtor relations. This essay focuses on the dialectical relationship between the abstract and particular, between the calculus of capital and concrete materialities, between formal equality and substantive difference, between wealthfare and debtfare, between the free and unfree, and between specific understandings of obligation and opportunity in the politics of consumer credit and debt. New money forms not only challenge the familiar taxonomies within which money has been understood but also blur the boundaries between money, commodity, labor, and capital. Current financial developments, including different business models centered on the “free culture” associated with the Internet (free content, free labor, etc.) are caught up in this process, reworking wider social experiences of time and the future and challenging the idea that the value captured in the money form can be fixed in time and place. This article argues that money as the designator of value is always contested, and that the indeterminacy of money as a means of exchange and as a measure of value that cannot be assured is a process that engages the simultaneous transformation of economic orders, subjective investments, and social relations.
Labor-Community Alliances in South Africa: Reclaiming (Some Of) the Past, Inventing the Future?
Authors: McKinley Dale T.
Published: April 2015

The decision by the National Union of Metalworkers (NUMSA) in late 2013 to break its long-standing alliance with the ruling African National Congress (ANC) and its political partner, the South African Communist Party (SACP), represents a watershed moment for left and progressive forces in South Africa. For the first time since the democratic breakthrough in 1994, there is a very real possibility of forging a mass-based and sustained, united front of action for labor and community struggles. Translating possibility into practice will be difficult. Even if there is much in the rich history of labor-community alliances that can be reclaimed, there are many obstacles. What contemporary labor-community alliances that do exist are extremely weak, and there are a variety of disconnections between unionized workers and the “other” (community-based) working class. Regardless, the combination of the “NUMSA moment,” the ongoing fracturing of the ANC’s political and ideological hegemony and a renewed militancy among the broad working class in conditions of consistent socioeconomic crisis have opened the doors not just for new labor-community alliances but also for a broad working class–led movement to mount a serious political challenge to the ANC and the state it controls.
Error Bounds for Augmented Truncations of Discrete-Time Block-Monotone Markov Chains under Geometric Drift Conditions
Authors: Masuyama Hiroyuki
Published: April 2015

In this paper we study the augmented truncation of discrete-time block-monotone Markov chains under geometric drift conditions. We first present a bound for the total variation distance between the stationary distributions of an original Markov chain and its augmented truncation. We also obtain such error bounds for more general cases, where an original Markov chain itself is not necessarily block monotone but is blockwise dominated by a block-monotone Markov chain. Finally, we discuss the application of our results to GI/G/1-type Markov chains.
Variance Optimal Stopping for Geometric Lévy Processes
Authors: Gad Kamille Sofie Tågholt , Pedersen Jesper Lund
Published: April 2015

The main result of this paper is the solution to the optimal stopping problem of maximizing the variance of a geometric Lévy process. We call this problem the variance problem. We show that, for some geometric Lévy processes, we achieve higher variances by allowing randomized stopping. Furthermore, for some geometric Lévy processes, the problem has a solution only if randomized stopping is allowed. When randomized stopping is allowed, we give a solution to the variance problem. We identify the Lévy processes for which the allowance of randomized stopping times increases the maximum variance. When it does, we also solve the variance problem without randomized stopping.
Persistence Probability for a Class of Gaussian Processes Related to Random Interface Models
Authors: Sakagawa Hironobu
Published: April 2015

We consider a class of Gaussian processes which are obtained as height processes of some (d+ 1)-dimensional dynamic random interface model on ℤd. We give an estimate of persistence probability, namely, largeTasymptotics of the probability that the process does not exceed a fixed level up to timeT. The interaction of the model affects the persistence probability and its asymptotics changes depending on the dimensiond.
Occupation Times, Drawdowns, and Drawups for One-Dimensional Regular Diffusions
Authors: Zhang Hongzhong
Published: April 2015

The drawdown process of a one-dimensional regular diffusion process X is given by X reflected at its running maximum. The drawup process is given by X reflected at its running minimum. We calculate the probability that a drawdown precedes a drawup in an exponential time-horizon. We then study the law of the occupation times of the drawdown process and the drawup process. These results are applied to address problems in risk analysis and for option pricing of the drawdown process. Finally, we present examples of Brownian motion with drift and three-dimensional Bessel processes, where we prove an identity in law.
BRAVO for Many-Server QED Systems with Finite Buffers
Authors: Daley D. J. , Van Leeuwaarden Johan S. H. , Nazarathy Yoni
Published: April 2015

This paper demonstrates the occurrence of the feature called BRAVO (balancing reduces asymptotic variance of output) for the departure process of a finite-buffer Markovian many-server system in the QED (quality and efficiency-driven) heavy-traffic regime. The results are based on evaluating the limit of an equation for the asymptotic variance of death counts in finite birth-death processes.
Permutation Monotone Functions of Random Vectors with Applications in Financial and Actuarial Risk Management
Authors: Li Xiaohu , You Yinping
Published: April 2015

In this paper we develop two permutation theorems on argument increasing functions of a multivariate random vector and a real parameter vector. We use the unified approach of our two theorems to provide some important theoretical results on the capital allocation in actuarial science, the deductible and upper limit allocations in insurance policy, and portfolio allocation in financial engineering. Our results successfully improve or extend the corresponding works in the literature.
The potential effects of climate change-associated temperature increases on the metabolic rate of a small Afrotropical bird
Authors: Thompson Lindy J. , Brown Mark , Downs Colleen T.
Published: April 2015

Studies have only recently begun to underline the importance of including data on species’ physiological flexibility when modelling their vulnerability to extinction from climate change. We investigated the effects of a 4°C increase in ambient temperature (Ta), similar to that predicted for southern Africa by the year 2080, on certain physiological variables of a 10-12g passerine bird endemic to southern Africa, the Cape white-eye Zosterops virens. There was no significant difference in resting metabolism, body mass and intraperitoneal body temperature between birds housed indoors at 4°C above outside ambient temperature and those housed indoors at outside ambient temperature. We conclude that Cape white-eyes’ physiological flexibility will aid them in coping with the 4°C increase predicted for their range by 2080.
Warm acclimation and oxygen depletion induce species-specific responses in salmonids
Authors: Anttila Katja , Lewis Mario , Prokkola Jenni M. , Kanerva Mirella , Seppänen Eila , Kolari Irma , Nikinmaa Mikko
Published: April 2015

Anthropogenic activities are greatly altering the habitats of animals, whereby fish are already encountering several stressors simultaneously. The purpose of the current study was to investigate the capacity of fish to respond to two different environmental stressors (high temperature and overnight hypoxia) separately and together. We found that acclimation to increased temperature (from 7.7±0.02°C to 14.9±0.05°C) and overnight hypoxia (daily changes from normoxia to 63-67% oxygen saturation), simulating climate change and eutrophication, had both antagonistic and synergistic effects on the capacity of fish to tolerate these stressors. Thermal tolerance of Arctic char (Salvelinus alpinus) and landlocked salmon (Salmo salar m. Sebago) increased with warm acclimation by 1.3°C and 2.2°C, respectively, but decreased when warm temperature was combined with overnight hypoxia (by 0.2°C and 0.4°C, respectively). In contrast, the combination of the stressors more than doubled hypoxia tolerance in salmon and also increased the tolerance in char by 22%. Salmon had 1.2°C higher thermal tolerance than char, but char tolerated much lower oxygen levels than salmon at a given temperature. The changes in hypoxia tolerance were connected to the responses of the oxygen supply and delivery system. The relative ventricle mass was higher in cold than warm acclimated salmon but the thickness of compact layer of ventricle increased with combination of warm and hypoxia acclimation in both species. Char had also significantly larger hearts and thicker compact layers than salmon. The results illustrate that while fish can have protective responses when encountering single environmental stressor, the combination of stressors can have unexpected species-specific effects which will influence their survival capacity.
Influence of Metal Oxides Impregnated on Silica—Alumina in the Removal of Sulphur and Nitrogen Compounds from a Hydrotreated Diesel Fuel Stream
Authors: Silveira E.B. , Veloso C.O. , Costa A.L.H. , Henriques C.A. , Zotin F.M.Z. , Paredes M.L.L. , Reis R.A. , Chiaro S.S.X.
Published: April 2015

The environmental legislation of many countries imposes severe restrictions on the emissions of gaseous pollutants, including NOx and SOx. Efficient alternatives for the removal of nitrogen and sulphur contaminants are required to obtain increasingly cleaner fuels. In this regard, adsorption is economically promising, because it requires less energy than the traditional hydrotreating processes due to mild conditions of temperature and pressure required. The objective of this study was to evaluate the influence of nickel, cerium, molybdenum and cobalt oxides impregnated on silica–alumina in removing nitrogen and sulphur compounds from a hydrotreated diesel. The incorporation of metal oxides increased the density of acid sites and promoted the removal of nitrogen and sulphur compounds, especially the one impregnated with molybdenum oxide. The influence of molybdenum oxide loading was also studied. It was observed that this synthesis parameter affected acid sites density and contaminant removal.
Purification of Peroxidase from Rice Bran Using Expanded-Bed Ion-Exchange Chromatography
Authors: Gautério G.V. , Fernandes S.S. , Molon F.O. , Figueira F.S. , Buffon J.G. , Kalil S.J.
Published: April 2015

Peroxidase catalyzes the oxidation of various substrates at the expense of hydrogen peroxide. Among the various techniques used for the purification of enzymes, expanded-bed adsorption chromatography is particularly popular because it offers several advantages, such as greater interactions between adsorbents and target molecules, increased overall yield, potential for a scale-up and shorter process times. It relies on the interaction between charged molecules in the mobile phase (i.e. buffer and sample) and oppositely charged groups coupled to the resin in the expanded-bed form. Other chromatographic techniques are also commonly used for peroxidase purification and characterization; however, there are no reports in the literature about the use of expanded-bed adsorption chromatography for this purpose. In this paper, the purification of peroxidase from rice bran using ion-exchange chromatography (expanded-bed column) was investigated. Chromatographic assays were carried out using STREAMLINE SP cationic resin with different buffer solutions and pH values in the equilibrium, washing and elution steps. The use of 0.025 mol/l sodium acetate buffer at pH 4.5 (during equilibration and washing) and 4.7 (during elution) allowed for the purification of peroxidase from rice bran, resulting in a purification factor and enzyme recovery of 2.4-fold and 41%, respectively.
Decarbonization of the Electrical Power Sector in Europe: An Asset, An Opportunity or a Problem?
Authors: Clerici Alessandro , Cova Bruno , Callegari Gabriele
Published: April 2015

Climate change has become a priority issue since the beginning of the '90s, but binding agreements on GHG (Greenhouse Gas) emission reduction valid worldwide have not been reached yet. The European Union has been a forerunner on regional binding targets with its “20-20-20” Climate and Energy Package approved in 2009, followed in Dec. 2011 by more ambitious targets implying a dramatic reduction by 2050 of GHG emissions to 80–95% below 1990 levels.

After a review of the present world situation with respect to primary energy resources, electricity production and CO2 emissions, the paper addresses the present and foreseen penetration of the power generation from RES (Renewable Energy Sources) in the EU (European Union), underlining also the economic impact on final clients caused by generous feed in tariffs.

The impact of a substantial increase of RES generation both in power and energy on the power market operation and system reliability and security are presented with practical examples from the Italian situations; e.g.: distortion of the day-ahead power market prices, critical load following requirements for conventional plants, need for additional reserve and risk of excess of non-programmable generation (“overgeneration”) in some hours, risk of dynamic stability and worsening of power quality.

The main solutions to overcome the above problems are reviewed and a methodology developed by CESI is described explaining how to attain the maximum share of RES generation in a specific power system, in compliance with reliability and security standards.

In authors'opinion, the technical and economic aspects must be treated together and it is mandatory to arrive quickly at agreed costs for the environmental impact of electrical infrastructures, particularly CO2 and other GHG emissions. Coherently, new RES generation and related network assets must be planned in an appropriate way to be a real asset and not a problem.
Wind Power Integration to the Transmission Grid: The Egyptian Perspective
Authors: Shalaby Fathalla M. L. , Helmi Abdelraheem , Helmi Dalai , Georgy Laila , El-Khayat Mohamed , Ibrahiem Mohamed
Published: April 2015

The Government of Egypt has recognized that the availability of reliable power supply is essential for economic and social prosperity and human development as well as for attracting private sector investments in the country. Egyptian Economic reform and growth have triggered a rapid increase in electricity demand. Peak load growth rate averaged 7 % p.a. in 2005–2008 and reached as high as 12% in 2008/09. In response to the rapid growth in demand, the supply capacity has expanded through an ambitious power sector investment program that has been under implementation since 2002. The Government's new energy strategy is aiming to increase the share of renewable energy to 20 % by the year 2020. 12% of this value, i.e 7200 MW, is from wind resources.

The complexity of the interconnection of wind farms to the power grid stems from the fact that wind energy is rather unstable and available only during certain hours of the day. By its nature the wind power generation may drop suddenly. To keep the grid operation stable, there is a need to ensure that other power generation sources are available to compensate for the drop. Another common characteristic of the wind farms is that they are located somewhat remote from the power grid. Therefore, the utility has to ensure the sufficiency of power transmission capacity. A rather unique feature of wind power in Egypt is that most of the wind resources are concentrated in the Gulf of Suez and Eastern and Western bank of Nile River areas. This raises the additional issue of the impact on the system when large amount of wind power are interconnected at certain points of the network and not distributed over along the country. The effects of having 3000 MW in Gulf of Suez and 4200 MW at Western Nile River areas depend very much on the local wind climate and the typical hour-to-hour load curve (electricity demand).

Some important issues needed to be considered are therefore: how should wind farms be expected to behave and perform, and which requirements should be imposed in order to expect wind farms to support the system? Is it realistic to expect wind turbines and wind farms to behave as any other power plant? What is the Impact on thermal loading of lines/transformers? What are the Power Quality Aspects should be mitigated? What is the behaviour during grid faults/Fault ride through? Reactive power compensation and voltage control…..etc. Grid codes are set up to specify the relevant requirements which have to be met in order to integrate wind turbines into the grid.

This paper will focus on The Egyptian approach to integrate wind power to the Egyptian Power System and the important issues related to system operation, stability, protection and the associated technical issues. Grid code requirements for large scale integration of wind power will also be illustrated.