bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of Prescription Drug Costs in the United States and the United Kingdom, Part 1: Statins
Authors: Jick Hershel , Wilson Andrew , Wiggins Peter , Chamberlin Douglas P.
Published: September 2012

Study Objective

To compare the annual cost of statins in the United States and in the United Kingdom.

Design

Matched‐cohort cost analysis.

Data Sources

U.K. General Practice Research Database (GPRD), and MarketScan Commercial Claims and Encounters Database, a large, U.S. self‐insured medical claims database.

Study Population

We initially identified 1.6 million people in the GPRD who were younger than 65 years of age in 2005. These people were then matched by year of birth and sex with 1.6 million people in the U.S. database. From this matched pool, we estimated that 280,000 people aged 55–64 years from each country in 2005 were prescribed at least one drug. Of these, 91,474 (33%) in the U.S. were prescribed a statin compared with 68,217 (24%) in the U.K. After excluding those who did not receive statins continuously or who switched statins during the year, there remained 61,470 in the U.S. and 45,788 in the U.K. who were prescribed a single statin preparation continuously during 2005 (annual statin users). We estimated and compared drug costs (presented in 2005 U.S. dollars) separately in the two countries.

Measurements and Main Results

Estimated drug costs were determined by random sampling. Estimated annual costs/patient in the U.S. ranged from $313 for generic lovastatin to $1428 for nongeneric simvastatin. In the U.K., annual costs/patient ranged from $164 for generic simvastatin to $509 for nongeneric atorvastatin. The total annual cost of the continuous receipt of statins in the U.S. was $64.9 million compared with $15.7 million in the U.K. In June 2006, after our study results were analyzed, the U.S. Food and Drug Administration approved generic simvastatin. We thus derived cost estimates for simvastatin use during 2006 and found that more than 60% of simvastatin users switched to the generic product, which reduced the cost/pill by more than 50%.

Conclusion

The cost paid for statins in the U.S. for people younger than 65 years, who were insured by private companies, was approximately 400% higher than comparable costs paid by the government in the U.K. Available generic statins were substantially less expensive than those that were still under patent in both countries.
Colony‐Stimulating Factor Use and Impact on Febrile Neutropenia Among Patients with Newly Diagnosed Breast, Colorectal, or Non–Small Cell Lung Cancer Who Were Receiving Chemotherapy
Authors: McCune Jeannine S. , Sullivan Sean D. , Blough David K. , Clarke Lauren , McDermott Cara , Malin Jennifer , Ramsey Scott
Published: September 2012

Study Objective

To determine the impact of primary prophylactic colony‐stimulating factor (CSF) use on febrile neutropenia in a large patient population receiving contemporary chemotherapy regimens to treat breast cancer, colorectal cancer, or non–small cell lung cancer (NSCLC).

Design

Retrospective claims analysis.

Data Sources

The Surveillance, Epidemiology, and End Results (SEER)‐Puget Sound cancer registry and insurance claims records.

Patients

A total of 2728 patients aged 25 years or older who received a diagnosis of breast cancer (998 patients), colorectal cancer (688 patients), or NSCLC (1042 patients) between January 1, 2002, and December 31, 2005, and received chemotherapy.

Measurements and Main Results

Initial chemotherapy regimen, CSF use (filgrastim or pegfilgrastim), and febrile neutropenia events were evaluated after the first chemotherapy administration. Subsequently, febrile neutropenia rates in patients receiving primary prophylactic CSF were compared with febrile neutropenia rates in patients receiving CSF in settings other than primary prophylaxis or not at all. The impact of primary prophylactic CSF could not be assessed for patients with colorectal cancer or NSCLC because only 1 and 18 febrile neutropenia events, respectively, occurred in those receiving primary prophylactic CSF. Of the 998 patients with breast cancer, 72 (7.2%) experienced febrile neutropenia, 28 of whom received primary prophylactic CSF. In the patients with breast cancer, we observed that primary prophylactic CSF use was associated with reduced febrile neutropenia rates; however, the analysis may have been confounded by unmeasured factors associated with febrile neutropenia.

Conclusion

The impact of primary prophylactic CSFs on febrile neutropenia rates could not be demonstrated. Given the substantive cost of CSFs to pharmacy budgets, there are numerous opportunities for pharmacists to optimize CSF use. Research studies are needed to evaluate if guideline‐directed prescribing of primary prophylactic CSFs can improve clinical outcomes.
Dapagliflozin: A Novel Sodium‐Glucose Cotransporter Type 2 Inhibitor for the Treatment of Type 2 Diabetes Mellitus
Authors: Shah Niren K. , Deeb Wasim E. , Choksi Rushab , Epstein Benjamin J.
Published: September 2012

The prevalence of diabetes mellitus has grown to staggering numbers, and its incidence is expected to rise in the next 2 decades. The need for novel approaches to treat hyperglycemia cannot be ignored. Current agents have been shown to modestly improve glycemia and in some cases prevent complications of diabetes, but they become less effective over time and are often accompanied by undesirable adverse effects. Dapagliflozin is the lead agent in a new class of oral antidiabetic agents known as sodium‐glucose cotransporter type 2 (SGLT2) inhibitors, which represent a novel approach to the management of type 2 diabetes mellitus. By selectively and reversibly blocking the SGLT2 receptor, dapagliflozin prevents the reabsorption of glucose at the renal proximal tubule. Phase II and III clinical trials have demonstrated that dapagliflozin is a safe and effective method for treating type 2 diabetes. Dapagliflozin produces a sustained, dose‐dependent reduction in plasma glucose levels while simultaneously improving insulin secretion and sensitivity. Over 12–24 weeks, reductions in hemoglobin A1c ranged from 0.54–0.89% when dapagliflozin was administered once/day (either as monotherapy or add‐on therapy to oral antidiabetic drugs with or without insulin) to patients with type 2 diabetes. Therapy with dapagliflozin also results in a mild osmotic‐diuretic effect that may account for decreases in total body weight (~2–3 kg) and blood pressure (systolic 2–5 mm Hg, diastolic 1.5–3 mm Hg), and increases in hematocrit (1–2%). Dapagliflozin has a favorable safety profile, with the rates of hypoglycemia similar to those of placebo. Genital and urinary tract infections were more commonly reported in patients taking dapagliflozin (2–13%) than those taking placebo (0–8%). Dapagliflozin does not appear to cause electrolyte disturbances, hepatotoxicity, or nephrotoxicity. Results from clinical trials have been promising, and well‐designed clinical programs that address the long‐term safety and efficacy of dapagliflozin are under way.
Fanconi's Syndrome and Nephrogenic Diabetes Insipidus in an Adult Treated with Ifosfamide
Authors: Ingemi Amanda I. , Bota Vasile M. , Peguero Anyeri , Charpentier Margaret
Published: September 2012

Fanconi's syndrome is a serious condition characterized by type II proximal renal tubular dysfunction, with urinary loss of glucose, amino acids, phosphate, bicarbonate, and potassium. Ifosfamide‐induced Fanconi's syndrome is reported in about 1.4–5% of children being treated for solid tumors, yet only a few cases have been reported in adults. We describe a 54‐year‐old man who came to the hospital with symptoms of neutropenic fever 4 days after his fourth cycle of ifosfamide and doxorubicin treatment for recurrent sarcoma with metastases to the lung. During admission, he was noted to have severe renal tubular dysfunction; ifosfamide‐induced nephrogenic diabetes insipidus and Fanconi's syndrome were suspected. He received supportive therapy that resulted in incomplete resolution of signs and symptoms. The patient was discharged after a 5‐day hospital stay when his white blood cell count increased from 0.1–2.5 × 103/mm3 and his fever had resolved. Use of the Naranjo adverse drug reaction probability scale indicated a probable relationship (score of 7) between the patient's development of diabetes insipidus and Fanconi's syndrome and his use of ifosfamide. This dual diagnosis of diabetes insipidus and Fanconi's syndrome in an adult makes this case unusual, as well as therapeutically challenging. We conducted a review of the existing literature regarding ifosfamide‐induced Fanconi's syndrome and describe the proposed mechanisms and therapeutic options. This case suggests that patients treated with ifosfamide should be monitored closely for renal function to identify, and perhaps prevent, these rare adverse events. Preliminary animal models show promise for adding N‐acetylcysteine to ifosfamide treatment, but more research is necessary before using this drug as a therapeutic option.
Liraglutide‐Induced Acute Kidney Injury
Authors: Kaakeh Yaman , Kanjee Sanna , Boone Kevin , Sutton James
Published: September 2012

Published case reports have documented the relationship between exenatide use and acute kidney injury. However, to our knowledge, no cases of this adverse effect with liraglutide, another glucagon‐like peptide‐1 receptor agonist approved for the treatment of type 2 diabetes mellitus, have been reported. We describe a 53‐year‐old Caucasian woman who came to a community hospital with severe and progressively worsening gastrointestinal symptoms for several weeks, leading to dehydration and development of acute kidney injury. Laboratory results showed an increase in her serum creatinine concentration to 22.8 mg/dl and blood urea nitrogen to 150 mg/dl; she also had lost 8.9 kg in the previous month. One month earlier, the patient had begun liraglutide 1.8 mg/day subcutaneously for uncontrolled type 2 diabetes. Use of the Naranjo adverse drug reaction probability scale indicated a possible relationship (score of 3) between the patient's development of acute kidney injury and liraglutide. Renal biopsy and laboratory testing were helpful in ruling out other potential causes of renal failure and adverse drug reactions due to other drugs such as ciprofloxacin and quinapril. After the reports of the renal biopsy were obtained, liraglutide was determined to be a likely cause of acute tubular necrosis. The patient was successfully treated with discontinuation of liraglutide, volume repletion, and hemodialysis. To our knowledge, this is the first documented case of liraglutide‐induced acute tubular necrosis. Clinicians should be aware of this possible complication and closely follow liraglutide's dosage titration recommendations in the package insert. Patients should also be educated about the need to report unusual or prolonged gastrointestinal symptoms.
Prasugrel as a Safe Alternative for Clopidogrel‐Induced Polyarthralgias
Authors: Coulter Chad J. , Montandon Shari V.
Published: September 2012

Clopidogrel is an oral thienopyridine that has been shown to reduce the risk of vascular death in patients with acute coronary syndrome, ischemic stroke, and peripheral vascular disease. The drug is associated with rare adverse effects such as thrombotic thrombocytopenia purpura, acute hepatotoxicity, and neutropenia. Only six cases have been reported that link acute arthritis with the use of clopidogrel. We describe a 64‐year‐old Caucasian man with sudden onset of severe arthritis, erythema, and swelling after starting clopidogrel therapy; he had no history of arthralgias while taking prasugrel during the previous 8 months. The patient was hospitalized for 3 days, and after cessation of clopidogrel therapy and conservative management, he improved dramatically, showing resolution of his joint erythema and swelling. The patient started prasugrel therapy at discharge, and no arthritic development was noted 8 weeks later. Although clopidogrel is commonly well tolerated, this case report demonstrates that clinicians should be aware that acute arthritis may be a possible adverse effect of clopidogrel. Additionally, polyarthralgias may not be a class effect of thienopyridines; patients who experience acute arthralgias during clopidogrel therapy may not experience similar adverse effects with prasugrel.
Boceprevir: A Novel NS3/4 Protease Inhibitor for the Treatment of Hepatitis C
Authors: Klibanov Olga M. , Vickery Stephen B. , Olin Jacqueline L. , Smith Lisa S. , Williams Shannon H.
Published: September 2012

Hepatitis C virus (HCV) infection affects over 170 million people worldwide and is the most common blood‐borne infection in the United States. Standard treatment with peginterferon alfa–ribavirin results in low sustained virologic response (SVR) rates in many patients, especially those who are African‐American, are coinfected with human immunodeficiency virus (HIV), or have liver cirrhosis. Because of suboptimal SVR rates, new direct‐acting antiviral agents that target HCV viral replication steps are in development. Boceprevir is one of the novel NS3/4A protease inhibitors that was recently approved by the U.S. Food and Drug Administration. We evaluated the literature regarding boceprevir by performing a MEDLINE search (January 1996–July 2011) to identify relevant clinical trials. Abstracts and poster and oral presentations from hepatology and HIV conferences were also reviewed. Potent anti‐HCV activity was seen in clinical trials with boceprevir when it was studied in HCV genotype 1‐infected patients who were naïve to or had experience with HCV therapy. Data with boceprevir in HIV–HCV‐coinfected patients are currently lacking; however, initial data on drug–drug interactions between boceprevir and antiretrovirals have become available. Resistance to boceprevir has been evaluated in trials as well, although more data are needed in this area. The most common adverse events with boceprevir included anemia and dysgeusia. Based on available data, boceprevir is one of the promising novel direct‐acting antiviral agents that will likely reshape the treatment of patients with HCV infection.
Dynamic GSCA (Generalized Structured Component Analysis) with Applications to the Analysis of Effective Connectivity in Functional Neuroimaging Data
Authors: Jung Kwanghee , Takane Yoshio , Hwang Heungsun , Woodward Todd S.
Published: September 2012

We propose a new method of structural equation modeling (SEM) for longitudinal and time series data, named Dynamic GSCA (Generalized Structured Component Analysis). The proposed method extends the original GSCA by incorporating a multivariate autoregressive model to account for the dynamic nature of data taken over time. Dynamic GSCA also incorporates direct and modulating effects of input variables on specific latent variables and on connections between latent variables, respectively. An alternating least square (ALS) algorithm is developed for parameter estimation. An improved bootstrap method called a modified moving block bootstrap method is used to assess reliability of parameter estimates, which deals with time dependence between consecutive observations effectively. We analyze synthetic and real data to illustrate the feasibility of the proposed method.
Moving Across Boundaries: Migration in South Africa, 1950–2000
Authors: Reed Holly E.
Published: September 2012

Existing knowledge about historical patterns of black internal migration in South Africa is incomplete, primarily because of the lack of good life course studies as well as the apartheid government’s suppression and censoring of data. This article provides a comprehensive picture of historical internal migration patterns with an analysis of a unique individual retrospective life history data set. This sample of the black population, collected in 2000, is the only known nationally representative life history data for South Africa; it includes all residential moves for each individual during his/her lifetime. Various mobility outcomes are analyzed: moves within/across provinces, moves within/across rural and urban areas, forced moves, moves with a nuclear family, and individual moves. The results indicate that migration significantly increased among black South Africans during the last half of the twentieth century, and that this increase began before the Pass Laws were repealed in 1986 and well before the official end of apartheid in 1991 or the first free election in 1994. The timing of this increase in migration rates suggests that migration in defiance of the Pass Laws (albeit a dangerous and desperate proposition) was a way of life for many black South Africans.
Butyrylcholinesterase as a prognostic marker: a review of the literature
Authors: Santarpia Lidia , Grandone Ilenia , Contaldo Franco , Pasanisi Fabrizio
Published: September 2012

Background

Butyrylcholinesterase (BChE) is an α‐glycoprotein synthesized in the liver. Its serum level decreases in many clinical conditions such as acute and chronic liver damage, inflammation, injury and infections, and malnutrition.

Methods and results

This review collects the main evidence on the emerging role of butyrylcholinesterase as a prognostic marker of liver and nonliver diseases as well as a marker of protein‐energy malnutrition and obesity. In fact, serum concentrations and BChE activity seem to accurately reflect the availability of amino acidic substrates and/or derangement in protein synthesis due to hepatocellular damage. In cancer, with or without liver impairment, serum BChE levels serve as an accurate functional and prognostic indicator, useful for monitoring clinical and therapeutic interventions according to patients’ prognosis. In the absence of inflammation, BChE could also serve as an index of the effectiveness of nutritional support.

Conclusions

Serum BChE assessment should be included in routine clinical diagnostic procedures to evaluate patient clinical conditions, in particular in cases of inflammation and/or protein‐energy malnutrition.
Adapting maize crop to climate change
Authors: Tokatlidis Ioannis S.
Published: September 2012

Global weather changes compel agriculture to be adequately productive under diverse and marginal conditions. In maize, modern hybrids fail to meet this requirement. Although breeding has achieved spectacular progress in grain yield per area through improved tolerance to stresses, including intense crowding, yields at low plant population densities remain almost unchanged. Stagnated plant yield potential renders hybrids unable to take advantage of resource abundance at lower populations, designating them population dependent. Consequently, the optimum population varies greatly across environments. Generally, the due population increases as the environmental yield potential gets higher. As a remedy, relatively low populations are recommended for low-input conditions leading to inappropriate population in occasional adequacy of resources and considerable yield loss. For example, for a rain-fed hybrid tested at one location across 11 seasons, crop yield potential and optimum population on the basis of the quadratic yield-plateau model varied from 1,890 to 8,980 kg/ha and 4.56 to 10.2 plants/m2, respectively, while 100 % yield loss is computed in the driest season if the optimum population for the most favorable season is used. The article reviews the consequences in terms of crop sustainability under widely diverse environments imposed by climatic changes and proposes crop management strategies to address the situation. The major points are: (1) variable-yielding environments require variable optimum populations, (2) population dependence is an insurmountable barrier in making a decision on plant population, (3) farmers suffer from considerable yield and income loss, (4) estimating the less population-dependent hybrids among the currently cultivated ones is a major challenge for agronomists, and (5) the development of population-neutral hybrids is a fundamental challenge for maize breeding. Honeycomb breeding is a valuable tool to pursue this goal since it places particular emphasis on the so-far stagnated plant yield potential that is essential for population-neutral hybrid development.
Markov Chains and Stochastic Stability
Authors: Meyn Sean , Tweedie Richard L. , Glynn Peter W.
Published: September 2012

Meyn and Tweedie is back! The bible on Markov chains in general state spaces has been brought up to date to reflect developments in the field since 1996 - many of them sparked by publication of the first edition. The pursuit of more efficient simulation algorithms for complex Markovian models, or algorithms for computation of optimal policies for controlled Markov models, has opened new directions for research on Markov chains. As a result, new applications have emerged across a wide range of topics including optimisation, statistics, and economics. New commentary and an epilogue by Sean Meyn summarise recent developments and references have been fully updated. This second edition reflects the same discipline and style that marked out the original and helped it to become a classic: proofs are rigorous and concise, the range of applications is broad and knowledgeable, and key ideas are accessible to practitioners with limited mathematical background.
Microsatellite loci over a thirty-three year period for a malaria parasite (Plasmodium mexicanum): bottleneck in effective population size and effect on allele frequencies
Authors: SCHALL J. J. , ST. DENIS K. M.
Published: September 2012

Changes in population allele frequencies may be driven by several forces, including selection and drift, and are revealed only by sampling over many generations. Such studies, however, are rare for protist parasites. Microsatellite allele frequencies for 4 loci were followed in a population ofPlasmodium mexicanum, a malaria parasite of lizards in California USA at 1 site from 1978 to 2010. Rapid turnover of the lizards indicates the parasite was studied for a minimum of 33 transmission cycles and possibly twice that number. Sample sizes ranged from 841 to 956 scored parasite clones per locus. DNA was extracted from frozen dried blood and blood removed from stained blood smears from the earliest years, and a verification study demonstrated DNA from the blood smears provided valid genetic data. Parasite prevalence and effective population size (Ne) dropped after 2000, remaining lower for the next decade. For 2 loci, allele frequencies appeared stable for the first 2 decades of the study, but changed more rapidly after the decline in prevalence. Allele frequencies changed more gradually for the other 2 loci. Genetic drift could account for changes in allele frequencies, especially after the drop in prevalence and Ne, but the force of selection could also have driven the observed patterns.
Epidemiological perspectives on West Nile virus surveillance in wild birds in Great Britain
Authors: BRUGMAN V. A. , HORTON D. L. , PHIPPS L. P. , JOHNSON N. , COOK A. J. C. , FOOKS A. R. , BREED A. C.
Published: September 2012

West Nile virus (WNV) is a zoonotic arthropod-borne pathogen with continued geographical expansion in Europe. We present and evaluate data on the temporal, spatial and bird species focus of the WNV surveillance programme in dead wild birds in Great Britain (2002–2009). During this period all bird samples tested negative for WNV. Eighty-two per cent of the 2072 submissions occurred during the peak period of vector activity with 53% tested during April–July before human and equine infection would be expected. Samples were received from every county, but there was significant geographical clustering (nearest neighbour index=0·23,P<0·001). Over 240 species were represented, with surveillance more likely to detect WNV in resident bird species (92% of submissions) than migrants (8%). Evidence indicates that widespread avian mortality is not generally a reported feature of WNV in Europe and hence additional activities other than dead bird surveillance may maximize the ability to detect WNV circulation before the onset of human and equine infections.
Annotating answer-set programs in Lana
Authors: DE VOS MARINA , KISA DOĞA GIZEM , OETSCH JOHANNES , PÜHRER JÖRG , TOMPITS HANS
Published: September 2012

While past research in answer-set programming (ASP) mainly focused on theory, ASP solver technology, and applications, the present work situates itself in the context of a quite recent research trend: development support for ASP. In particular, we propose to augment answer-set programs with additional meta-information formulated in a dedicated annotation language, called Lana. This language allows the grouping of rules into coherent blocks and to specify language signatures, types, pre- and postconditions, as well as unit tests for such blocks. While these annotations are invisible to an ASP solver, as they take the form of program comments, they can be interpreted by tools for documentation, testing, and verification purposes, as well as to eliminate sources of common programming errors by realising syntax checking or code completion features. To demonstrate its versatility, we introduce two such tools, viz. (i) ASPDoc, for generating an HTML documentation for a program based on the annotated information, and (ii) ASPUnit, for running and monitoring unit tests on program blocks. Lana is also exploited in the SeaLion system, an integrated development environment for ASP based on Eclipse.
Module theorem for the general theory of stable models
Authors: BABB JOSEPH , LEE JOOHYUNG
Published: September 2012

The module theorem by Janhunen et al. demonstrates how to provide a modular structure in answer set programming, where each module has a well-defined input/output interface which can be used to establish the compositionality of answer sets. The theorem is useful in the analysis of answer set programs, and is a basis of incremental grounding and reactive answer set programming. We extend the module theorem to the general theory of stable models by Ferraris et al. The generalization applies to non-ground logic programs allowing useful constructs in answer set programming, such as choice rules, the count aggregate, and nested expressions. Our extension is based on relating the module theorem to the symmetric splitting theorem by Ferraris et al. Based on this result, we reformulate and extend the theory of incremental answer set computation to a more general class of programs.
Diagrammatic confluence for Constraint Handling Rules
Authors: HAEMMERLÉ RÉMY
Published: September 2012

Confluence is a fundamental property of Constraint Handling Rules (CHR) since, as in other rewriting formalisms, it guarantees that the computations are not dependent on rule application order, and also because it implies the logical consistency of the program declarative view. In this paper we are concerned with proving the confluence of non-terminating CHR programs. For this purpose, we derive from van Oostrom's decreasing diagrams method a novel criterion on CHR critical pairs that generalizes all preexisting criteria. We subsequently improve on a result on the modularity of CHR confluence, which permits modular combinations of possibly non-terminating confluent programs, without loss of confluence.
Assessing BAILII in 2012
Authors: Fellows Cynthia S. , Leith Philip , Ury Joe
Published: September 2012

Cynthia Fellows, Philip Leith and Joe Ury report on the survey responses to a usage and attitudinal project carried out in early 2012 by the British and Irish Legal Information Institute (BAILII). There were 3,274 survey participants and their responses demonstrate substantial support for BAILII as an open access mechanism, a technically competent dissemination tool and a useful resource for lawyers and non-lawyers alike. Such positive response, we suggest, indicates that BAILII's resources are now threaded through the fabric of UK digital legal information, strengthening the ability of all citizens to access and become better informed about the laws of the land.
LawSync: Navigating the ‘Blue Oceans’ Within the ‘Emerging’ Legal Services Markets
Authors: Smith Pete , Whittle Richard , Griffith Peter
Published: September 2012

Change, it is said, is the only constant. Whilst it cannot be avoided, the worlds of legal education and legal services have arguably enjoyed an extended period where the impact of change has been comparatively minimal. Today, these worlds face significant changes due to a combination of market and regulatory forces. True, such changes are likely to be accompanied by challenges but with these challenges come opportunities. There is no reason why Law Schools and Law students cannot help to shape these changes and benefit from them. Peter Smith, Richard Whittle and Peter Griffith discuss LawSync™, a project that seeks to enable such influence and attract such benefits at Sheffield Hallam University. See http://www.lawsync.com and http://twitter.com/lawsync for more details.
E-learning and the Legal Foundations Course: It's (a bit of) a Revolution!
Authors: Fishleigh Jackie
Published: September 2012

In this article, Jackie Fishleigh reflects on her first taste of e-learning whilst undertaking the revamped Legal Foundations Course. She explains how the course now works and compares it to the original version she took 20 years ago. She also looks at the views on e-learning expressed by Professor Richard Susskind and educationalist, Alan Clarke. The advantages and disadvantages are explored, together with the characteristics of a successful e-learner. The article aims to be informative and entertaining.
Atom-Probe-Tomographic Studies on Silicon-Based Semiconductor Devices
Authors: Inoue Koji , Kambham Ajay Kumar , Mangelinck Dominique , Lawrence Dan , Larson David J.
Published: September 2012

The development of laser-assisted atom probe tomography (APT) and specimen preparation techniques using a focused ion beam equipped with high-resolution scanning electron microscopy (SEM) has significantly advanced the characterization of semiconductor devices by APT. The capability of APT to map out elements in devices at the atomic scale with high sensitivity meets the characterization requirements of semiconductor devices such as the determination of elemental distributions for each device region.
Mass loss and fate of the most massive stars
Authors: Vink Jorick S.
Published: September 2012

The fate of massive stars up to 300M⊙ is highly uncertain. Do these objects produce pair-instability explosions, or normal Type Ic supernovae? In order to address these questions, we need to know their mass-loss rates during their lives. Here we present mass-loss predictions for very massive stars (VMS) in the range of 60-300M⊙. We use a novel method that simultaneously predicts the wind terminal velocities v∞ and mass-loss rate Ṁ as a function of the stellar parameters: (i) luminosity/mass Γ, (ii) metallicity Z, and (iii) effective temperature Teff. Using our results, we evaluate the likely outcomes for the most massive stars.
Ultra High Energy Cosmic Rays from Engine-driven Relativistic Supernovae
Authors: Chakraborti Sayan
Published: September 2012

The sources of the highest energy cosmic rays remain an enigma half a century after their discovery. Understanding their origin is a crucial step in probing new physics at energies unattainable by terrestrial accelerators. They must be accelerated in the local universe as otherwise interaction with cosmic background radiations would severely deplete the flux of protons and nuclei at energies above the Greisen-Zatsepin-Kuzmin (GZK) limit. Hypernovae, nearby GRBs, AGNs and their flares have all been suggested and debated in the literature as possible sources. Type Ibc supernovae have a local sub-population with mildly relativistic ejecta which are known to be sub-energetic GRBs or X-Ray Flashes for sometime and more recently as those with radio afterglows but without detected GRB counterparts, such as SN 2009bb. In this talk we present the size-magnetic field evolution, baryon loading and energetics of SN 2009bb using its radio spectra obtained with VLA and GMRT. We show that the engine-driven SNe lie above the Hillas line and they can explain the characteristics of post-GZK UHECRs.
Constraining gamma-ray burst progenitors
Authors: Levan Andrew
Published: September 2012

The past decade has seen great progress towards the unmasking of the progenitors of gamma-ray bursts, starting with the unambiguous detection of a supernova in the light of the long-GRB 030329 almost ten years ago, and the discovery of the first afterglows to short-GRBs in 2005. Here I review progress towards unveiling the progenitors of both long and short-duration GRBs. Furthermore, I examine the diverse broader population of GRBs and high energy transients, and suggest that a full consideration of this parameter space leads to the conclusion that additional progenitor models are likely to be needed, if we are to understand the complete view of GRBs and the transient high-energy sky.
Identifying Supernova Progenitors and Constraining the Explosion Channels
Authors: Van Dyk Schuyler D.
Published: September 2012

Connecting the endpoints of massive star evolution with the various types of core-collapse supernovae (SNe) is ultimately the fundamental puzzle to be explored and solved. We can assemble clues indirectly, e.g., from information about the environments in which stars explode and establish constraints on the evolutionary phases of these stars. However, this is best accomplished through direct identification of the actual star that has exploded in pre-supernova imaging, preferably in more than one photometric band, where color and luminosity for the star can be precisely measured. We can then interpret the star's properties in light of expectations from the latest massive stellar evolutionary models, to attempt to assign an initial mass to the progenitor. So far, this has been done most successfully for SNe II-P, for which we now know that red supergiants in a relatively limited initial mass range are responsible. More recently, we have limited examples of the progenitors of SNe II-L, IIn, and IIb. The progenitors of SNe Ib and Ic, however, have been elusive so far; I will discuss the current status of our knowledge of this particular channel.
Spectropolarimetry of Type Ibc Supernovae
Authors: Tanaka Masaomi , Kawabata Koji S. , Hattori Takashi , Mazzali Paolo A. , Aoki Kentaro , Iye Masanori , Maeda Keiichi , Nomoto Ken'ichi , Pian Elena , Sasaki Toshiyuki , Yamanaka Masayuki
Published: September 2012

Studying a multi-dimensional structure of supernovae (SNe) gives important constraints on the mechanism of the SN explosion. Polarization measurement is one of the most powerful methods to study the explosion geometry of extragalactic SNe. Especially, Type Ib/c SNe are the ideal targets because the core of the explosion is bare. We have performed spectropolarimetric observations of Type Ib/c SNe with the Subaru telescope. We detect a rotation of the polarization angle across the line, which is seen as a loop in the Q - U plane. This indicates that axisymmetry is broken in the SN ejecta. Adding our new data to the sample of stripped-envelope SNe with high-quality spectropolarimetric data, five SNe out of six show a loop in the Q - U plane. This implies that the SN explosion commonly has a non-axisymmetric, three-dimensional geometry.
Gravitational waves and gamma-ray bursts
Authors: Corsi Alessandra ,   for the LIGO Scientific Collaboration and Virgo collaboration
Published: September 2012

Gamma-Ray Bursts are likely associated with a catastrophic energy release in stellar mass objects. Electromagnetic observations provide important, but indirect information on the progenitor. On the other hand, gravitational waves emitted from the central source, carry direct information on its nature. In this context, I give an overview of the multi-messenger study of gamma-ray bursts that can be carried out by using electromagnetic and gravitational wave observations. I also underline the importance of joint electromagnetic and gravitational wave searches, in the absence of a gamma-ray trigger. Finally, I discuss how multi-messenger observations may probe alternative gamma-ray burst progenitor models, such as the magnetar scenario.
Host Galaxies of Gamma-Ray Bursts
Authors: Levesque Emily M.
Published: September 2012

Host galaxies are an excellent means of probing the natal environments that generate gamma-ray bursts (GRBs). Recent work on the host galaxies of short-duration GRBs has offered new insights into the parent stellar populations and ages of their enigmatic progenitors. Similarly, surveys of long-duration GRB (LGRB) host environments and their ISM properties have produced intriguing new results with important implications for long GRB progenitor models. These host studies are also critical in evaluating the utility of LGRBs as potential tracers of star formation and metallicity at high redshifts. I will summarize the latest research on LGRB host galaxies, and discuss the resulting impact on our understanding of these events' progenitors, energetics, and cosmological applications.
Type Ib/c Supernovae with and without Gamma-Ray Bursts
Authors: Modjaz Maryam
Published: September 2012

While the connection between Long Gamma-Ray Bursts (GRBs) and Type Ib/c Supernovae (SNe Ib/c) from stripped stars has been well-established, one key outstanding question is what conditions and factors lead to each kind of explosion in massive stripped stars. One promising line of attack is to investigate what sets apart SNe Ib/c with GRBs from those without GRBs. Here, I briefly present two observational studies that probe the SN properties and the environmental metallicities of SNe Ib/c (specifically broad-lined SNe Ic) with and without GRBs. I present an analysis of expansion velocities based on published spectra and on the homogeneous spectroscopic CfA data set of over 70 SNe of Types IIb, Ib, Ic and Ic-bl, which triples the world supply of well-observed Stripped SNe. Moreover, I demonstrate that a meta-analysis of the three published SN 1b/c metallicity data sets when including only values at the SN positions to probe natal oxygen abundances, indicates at very high significance that indeed SNe Ic erupt from more metal-rich environments than SNe Ib, while SNe Ic-bl with GRBs still prefer, on average, more metal-poor sites than those without GRBs.
Magnetars and Gamma Ray Bursts
Authors: Bucciantini Niccolò
Published: September 2012

In the last few years, evidences for a long-lived and sustained engine in Gamma Ray Bursts (GRBs) have increased the attention to the so called millisecond-magnetar model, as a competitive alternative to the standard collapsar scenario. I will review here the key aspects of the millisecond magnetar model for Long Duration Gamma Ray Bursts (LGRBs). I will briefly describe what constraints present observations put on any engine model, both in terms of energetics, outflow properties, and the relation with the associated Supernova (SN). For each of these I will show how the millisecond magnetar model satisfies the requirements, what are the limits of the model, how can it be further tested, and what observations might be used to discriminate against it. I will also discuss numerical results that show the importance of the confinement by the progenitor star in explaining the formation of a collimated outflow, how a detailed model for the evolution of the central engine can be built, and show that a wide variety of explosive events can be explained by different magnetar parameters. I will conclude with a suggestion that magnetars might be at the origin of the Extended Emission (EE) observed in a significant fraction of Short GRBs.
Super iron-rich gas towards GRB 080310: SN yields or dust destruction?
Authors: De Cia A. , Ledoux C. , Vreeswijk P. , Fox A. , Smette A. , Petitjean P. , Björnsson G. , Fynbo J. , Hjorth J. , Jakobsson P.
Published: September 2012

We performed Rapid-Response Mode (RRM) VLT/UVES high-resolution UV/ optical spectroscopy of the GRB 080310 afterglow, starting 13 min after the burst trigger, in order to investigate the ISM in the GRB host galaxy. The four spectra show remarkable features at zGRB, including a low log N(H i) = 18.7 and time-variable absorption from ground-state and excited levels of Fe ii and Fe iii, the latter being observed for the first time in a GRB afterglow. These observations indicate i) ongoing photo-ionization of the surrounding gas due to the GRB radiation and ii) Fe and Cr overabundances in the host galaxy ISM. We derive ionic column densities through a four-component Voigt-profile fit of the absorption lines and investigate the pre-burst ionization level of the gas with CLOUDY photo-ionization modelling. The resulting intrinsic [Si/Fe] = −1.4 ([C/H] = −1.3, [O/H] < −0.8, [Si/H] = −1.2, [Cr/H] = +0.7 and [Fe/H] = +0.2) for the whole line profile - and even more extreme for one of the absorption components - cannot be explained with current models of SN yields. Dust destruction may contribute to the marked iron overabundance, possibly induced by the burst. The overall high iron enhancement along the line-of-sight also suggests little recent star formation in the host galaxy.
The Luminous Type Ibc Supernova 2010as
Authors: Folatelli Gastón
Published: September 2012

We present photometric and spectroscopic follow-up observations of SN 2010as carried out by the MCSS and CSP. The SN appears to be of the transitional type Ibc (SN Ibc) and is spectroscopically similar to the peculiar SN 2005bf. Based on distance and extinction estimates, a bolometric luminosity light curve is constructed showing that this was a relatively luminous SN Ibc. He i line expansion velocities are remarkably low and remain nearly constant with time, similarly to SN~2005bf. A preliminary model is presented with a progenitor ZAMS mass of 15 M⊙ and a large yield of 0.35 M⊙ of 56Ni.
The Ultra-Fast Flash Observatory's space GRB mission and science
Authors: Lim H. , Ahmad S. , Barrillon P. , Blin-Bondil S. , Brandt S. , Budtz-Jørgensen C. , Castro-Tirado A. J. , Chen P. , Choi H. S. , Choi Y. J. , Connell P. , Dagoret-Campagne S. , De La Taille C. , Eyles C. , Grossan B. , Hermann I. , Huang M.-H. A. , Jeong S. , Jung A. , Kim J. E. , Kim S.-W. , Kim Y. W. , Lee J. , Linder E. V. , Liu T.-C. , Lund N. , Min K. W. , Na G. W. , Nam J. W. , Nam K. H. , Panasyuk M. I. , Park I. H. , Reglero V. , Řípa J. , Rodrigo J. M. , Smoot G. F. , Svetilov S. , Vedenkin N. , Yashin I.
Published: September 2012

The Ultra-Fast Flash Observatory (UFFO) is a space mission to detect the early moments of an explosion from Gamma-ray bursts (GRBs), thus enhancing our understanding of the GRB mechanism. It consists of the UFFO Burst & Trigger telescope (UBAT) for the recognition of GRB positions using hard X-ray from GRBs. It also contains the Slewing Mirror Telescope (SMT) for the fast detection of UV-optical photons from GRBs. It is designed to begin the UV-optical observations in less than a few seconds after the trigger. The UBAT is based on a coded-mask X-ray camera with a wide field of view (FOV) and is composed of the coded mask, a hopper and a detector module. The SMT has a fast rotatable mirror which allows a fast UV-optical detection after the trigger. The telescope is a modified Ritchey-Chrétien telescope with the aperture size of 10 cm diameter, and an image intensifier readout by CCD. The UFFO pathfinder is scheduled to launch into orbit on 2012 June by the Lomonosov spacecraft. It is a scaled-down version of UFFO in order to make the first systematic study of early UV/optical light curves, including the rise phase of GRBs. We expect UBAT to trigger ~44 GRBs/yr and expect SMT to detect ~10 GRBs/yr.
Exploding SNe with jets: time-scales
Authors: Papish Oded , Soker Noam
Published: September 2012

We perform hydrodynamical simulations of core collapse supernovae (CCSNe) with a cylindrically-symmetrical numerical code (FLASH) to study the inflation of bubbles and the initiation of the explosion within the frame of the jittering-jets model. We study the typical time-scale of the model and compare it to the typical time-scale of the delayed neutrino mechanism. Our analysis shows that the explosion energy of the delayed neutrino mechanism is an order of magnitude less than the required 1051 erg.
Observations of GRBs in the mm/submm range at the dawn of the ALMA era
Authors: de Ugarte Postigo A. , Lundgren A. , Martín S. , García-Appadoo D. , de Gregorio Monsalvo I. , Thöne C.C. , Gorosabel J. , Castro-Tirado A. J. , Sánchez-Ramírez R. , Tello J. C.
Published: September 2012

Gamma-ray bursts (GRBs) generate an afterglow with an emission peaking in the millimetre and submillimeter (mm/submm) range during the first hours to days, making the study in these wavelengths of great importance. Here we give an overview of the data that has been collected for GRB observations in this wavelengths until September 2011. The total sample includes 102 GRBs, of which 88 have afterglow observations, and the rest are only host galaxy searches. The 22 detections cover the redshift range between 0.168 and 8.2 and have peak luminosities that span 2.5 orders of magnitude. With the start of the operations at ALMA, the sensitivity with respect to previous facilities has already improved by over an order of magnitude. We estimate that, once completed, ALMA will be able to detect ~98 % of the afterglows.

This proceeding is based on the work published by de Ugarte Postigo et al. (2012).
Spectral Evolutions Study of Gamma-Ray Burst Exponential Decays with Suzaku-WAM
Authors: Tashiro Makoto S. , Onda Kaori , Yamaoka Kazutaka , Ohno Masahiro , Sugita Satoshi , Uehara Takeshi , Seta Hiromi
Published: September 2012

An observational study is presented of the spectral evolution of gamma-ray burst (GRB) prompt emissions with the Suzaku Wide-band All-sky Monitor (WAM). We selected 6 bright GRBs exhibiting 7 well-separated fast-rise-exponential-decay (FRED) shaped light curves to investigate spectral changes by evaluating exponential decay time constants of the energy-resolved light curves. In addition, we carried out time-resolved spectroscopy of two of them which were located with accuracy sufficient to evaluate the time-resolved spectra with precise energy response matrices. The two imply different emission mechanisms; the one is well reproduced with a cooling blackbody radiation model with a power-law component, while the other prefers non-thermal emission model with a decaying turn over energy.
SVOM Visible Telescope: Performance and Data Process Scheme
Authors: Wu C. , Qiu Y. L. , Cai H. B.
Published: September 2012

VT (Visible Telescope) is an instrument onboard SVOM (Space-based multi-band astronomical Variable Objects Monitor) satellite working in the visible band, which will play an important role in follow-up of two categories of GRBs: very distant events at higher redshift and faint/soft nearby events in SVOM mission. To fulfill these primary science requirements, decent sensitivity and wavelength coverage are fundamental for VT design. VT performance and data process strategy were successfully studied on its feasibility in Phase A, which is presented in this poster. Additionally, preliminary VT image simulator is also introduced here.
Development of a micro-satellite TSUBAME for X-ray polarimetry of GRBs
Authors: Yatsu Yoichi , Hayashi Mayumi , Kawakami Kousuke , Tokoyoda Kazuki , Enomoto Takahiro , Toizumi Takahiro , Kawai Nobuyuki , Ishizaka Kazuya , Muta Azusa , Morishita Hiroyuki , Matsunaga Saburo , Nakamori Takeshi , Kataoka Jun , Kubo Shin
Published: September 2012

Hard X-ray polarization is believed to be one of the most promising methods to investigate the physical processes just around the central engines by constraining the magnetic environment. For this purpose we are now developing a compact and highly sensitive hard X-ray polarimeter aboard a university class micro-satellite “TSUBAME”. We are now developing the flight model of the satellite aiming for the launch in late 2012 from Russia.