bluuebunny/crossref_metadata_2025 huggingface dataset:
Kant's Justification of the Death Penalty Reconsidered
Authors: Yost Benjamin S.
Published: June 2011

It is hard to know what to think about Kant's ‘passionate sermons’ on capital punishment. Kant clearly feels that it is one of the most important punishments in the state's arsenal. But his vehement insistence on the necessity of execution strikes many readers as philosophically suspect. Critics argue that Kant's embrace of the death penalty is incompatible with, or at least not required by, the fundamental tenets of his moral and legal philosophy (Schwarzschild 1985; Merle 2000; Potter 2002; Hill 2003). These arguments typically employ one of two strategies. The first is to deny that execution is required by retribution in even a prima facie sense; arguments along this line typically question the coherence of Kant's doctrine of the ius talionis (Sarver 1997). The second is to show that there are inviolable moral principles that render the death penalty illegitimate; this criticism typically appeals to the value of human dignity or the right to life (Radin 1980; Pugsley 1981; Schwarzschild 1985; Merle 2000; Potter 2002). There is a third strategy that could be used to criticize Kant, although it is not aimed at him specifcally. This strategy invokes legal principles of fairness or due process. It asserts that, regardless of capital punishment's moral appropriateness or legitimacy, capital punishment is unjust due to the fallibility of legal actors and institutions (Nathanson 2001). Someone adopting the third strategy might claim that, while Kant's justifcation may be acceptable in principle, it fails to justify the death penalty in the world we live in.
Privacy, Respect and the Virtues of Reticence in Kant
Authors: Anderson-Gold Sharon
Published: June 2011

At a time when the public is increasingly exposed to public scandals, moral defences of privacy are hard to come by. Privacy, it is argued, is merely a cloak for deception and vice. Since the virtuous have nothing to hide, full disclosure of ourselves to others must be a moral obligation. Given the rigour with which Kant defends the prohibition on lying, many have inferred that Kantian ethics must be equally strict on the necessity of truth telling. Do we in fact owe others the truth, the whole truth and nothing but the truth?
Team-building with answer set programming in the Gioia-Tauro seaport
Authors: RICCA F. , GRASSO G. , ALVIANO M. , MANNA M. , LIO V. , IIRITANO S. , LEONE N.
Published: June 2011

The seaport of Gioia Tauro is the largest transshipment terminal of the Mediterranean coast. A crucial management task for the companies operating in the seaport is team-building: the problem of properly allocating the available personnel for serving the incoming ships. Teams have to be carefully arranged in order to meet several constraints, such as allocation of employees with appropriate skills, fair distribution of the working load, and turnover of the heavy/dangerous roles. This makes team-building a hard and expensive task requiring several hours of manual preparation per day.

In this paper we present a system based on Answer Set Programming for the automatic generation of the teams of employees in the seaport of Gioia Tauro. The system is currently exploited in the Gioia Tauro seaport by ICO BLG, a company specialized in automobile logistics.
The effect of spacecraft descent engine plumes on spore transfer to planetary surfaces: Phoenix as a test case
Authors: Marshall J.R. , Mancinelli R.L.
Published: June 2011

Laboratory experiments were conducted to determine the effect of descent-engine plumes on the scouring of surface (microbial) contaminants from a spacecraft. A simulated touchdown of a half-scale lander engine and deck configuration was conducted at Mars atmospheric pressure in the NASA Ames Planetary Aeolian Laboratory. Low-density particles were used for the soil simulant to emulate the lower Martian gravity. The underside of the model had small witness plates with controlled microbial surface populations and particle impact detectors. For both steady-state engine thrust (Viking) and pulsed engine thrust (Phoenix), the exhaust plumes from the engines violently excavated the soil and produced particle-laden eddies beneath the lander that sandblasted the lander underside. The result was nearly complete erosion of microbial contaminants from the spacecraft model with their subsequent deposition in the surrounding area. It is concluded that different planetary protection cleanliness levels for different parts of a spacecraft do not necessarily prevent soil contamination because these cleaning strategies evolved without consideration of the effects of the descent engine plumes.
The Social Science of Democracy?
Authors: Locke Jill
Published: June 2011

Alexis de Tocqueville, the First Social Scientist. By Jon Elster. New York: Cambridge University Press, 2009. 212p. $80.00 cloth, $22.99 paper.

Alexis de Tocqueville is surely one of the most widely cited, discussed, and celebrated political theorists in the world. Jon Elster's book, Alexis de Tocqueville: the First Social Scientist proceeds from a provocative premise: that Tocqueville's major works were lacking in “system” and were “hugely incoherent,” and that Tocqeuville himself “was not a major political thinker” (xi). Elster argues that instead Tocqueville ought to be viewed as a penetrating historical sociologist and an exemplary social scientist who might well be considered the first true social scientist. Elster's argument is important for at least two reasons: first, because it offers a striking and challenging reading of Tocqueville; and second, because it expands on Elster's own contributions in the philosophy of social science, and develops interesting understandings of “causal mechanisms,” methodological individualism, and social explanation more generally. As Elster writes in his Introduction, “the main task of this book is to argue for the relevance of Tocqueville for social science in the twenty-first century (p. 5).” The purpose of this Perspectives symposium is to assess Elster's argument in broad terms. What are the strengths and limits of Elster's reading of Tocqueville? How ought we to assess Elster's understanding of Tocqueville's deficiencies as a “political theorist?” What is the relevance of Tocqueville for contemporary social science? And, most importantly, what are the challenges and possible trajectories facing social science in the twenty-first century, and to what extent does Elster's essay point us in the right direction?—Jeffrey C. Isaac, Editor
Our Schools Suck: Students Talk Back to a Segregated Nation on the Failures of Urban Education. By Gaston Alonso, Noel S. Anderson, Celina Su, and Jeanne Theoharis. New York: New York University Press, 2009. 304p. $70.00 cloth, $23.00 paper.
Authors: Dunn Joshua M.
Published: June 2011

In a March 2006 New York Times editorial, sociologist Orlando Patterson highlighted and tried to explain the “tragedy unfolding in our inner cities,” particularly the “self-destructive” behavior of “young black men.” Provocatively, he identified what sociologists have labeled the “cool-pose culture” as the primary culprit. According to this “culture of failure” thesis, minority youth are partly responsible for this tragedy by choosing a lifestyle that disconnects them from the “socioeconomic mainstream.” It is this thesis that Our Schools Suck is determined to discredit. The authors, four scholars and also, importantly, self-professed activists, criticize scholars, politicians, political analysts, and entertainers, including Patterson, Barack Obama, Juan Williams, and Bill Cosby, for giving “nonwhite youth” a “moral flogging” rather than focusing on the real problem, “socioeconomic and school conditions” (p. 5). Instead of being unconcerned about education, they argue, urban minority youth value education and are acutely aware of their schools' shortcomings.
Enlivening the Concept of Democratization: The Biological Metaphor
Authors: Whitehead Laurence
Published: June 2011

Mechanical metaphors have colonized the social sciences, including the study of democratization processes. But they may provide a misleading framework for monitoring ongoing “self-equilibrating” social processes with no natural “end state” such as democratization. I propose that modern biology can be consulted as an alternative source of analogical reasoning, offering a more flexible and appropriate stock of metaphors that can enliven analogical accounts of processes of democratization. The shift towards modeling democracy as a living practice permanently directed towards self-preservation and propagation provides a clearer rationale for comparative studies, focussing on the relative “quality” of democracy in different contexts. I begin with a brief sketch of the historical instability and current contestability of most democratization processes; I then examine the morphology of complex political concepts and propose alternative biological analogies to replace the currently prevalent physicalist imagery.
Informationsbedarf von Menschen mit Ulcus cruris venosum. Expertenwissen Betroffener als Grundlage für patientenzentrierte Informationen
Authors: Schmitz Astrid
Published: June 2011

Patientenzentrierte Informationen orientieren sich an den Bedürfnissen der Menschen. Alltagsbewältigung und Leben-Lernen mit einer chronischen Erkrankung sind der Hauptfokus solcher Informationen. Für Menschen mit Ulcus cruris venosum (UCV) liegt bisher kein solches Informationsangebot vor. Um die Inhalte hierfür zu generieren, wurden eine Literaturanalyse sowie eine qualitative Sekundäranalyse von 27 Interviews mit Betroffenen durchgeführt. Beide Analysen zeigen die komplexen Auswirkungen der Erkrankung auf das Leben der Menschen. Die Dimensionen Alltagskompetenzen, Wissen, Techniken und Fertigkeiten sowie die Bedeutung der Angehörigen wurden identifiziert. Die Interviewanalyse verdeutlicht, dass Angehörige einerseits Teil des Unterstützungssystems und andererseits ebenfalls betroffen sind. Nach langen Krankheitsverläufen nehmen sich die Menschen als Experten wahr. Sie erlangen besondere Kompetenzen im Umgang mit der Erkrankung und bewerten ihr Wissen aufgrund ihrer Erfahrung höher als das der Mitglieder des Behandlungsteams. Die Teilnehmer besitzen teilweise individuelle Krankheitskonzepte. Medizinisches und pflegerisches Fachwissen ist nur eine von mehreren Wissensquellen. Die Betroffenen kennen und verwenden alternative Heilmethoden. Von Pflegenden und Ärzten fühlen sie sich häufig nicht ernstgenommen. Patientenzentrierte Informationsmaterialien können nicht nur Betroffene und ihre Angehörigen, sondern auch Pflegende und Ärzte, bei der professionellen Begleitung von Menschen mit UCV unterstützen.
The Discriminant Validity of Transformational and Transactional Leadership
Authors: Krüger Claudia , Rowold Jens , Borgmann Lars , Staufenbiel Kathrin , Heinitz Kathrin
Published: June 2011

The well known constructs of transformational and transactional leadership are still facing problems concerning their discriminant validity as substantive correlations have frequently been observed between them. Nine samples, including 178 supervisors and their 834 followers, completed the German version of the Transformational Leadership Inventory (TLI). Self-ratings and aggregated observer ratings were analyzed using a SEM-based multitrait-multimethod (MTMM) approach. First, the factorial structure was confirmed for both rating perspectives and across them. In the MTMM analysis, controlling for the method effects reduced the correlations between leadership constructs from a high to a small resp. medium level and the leadership scales can be discriminated. Facilitating the use of the TLI in practical issues, norms are provided for self and observer ratings.
A Multimedia Situational Test With a Constructed-Response Format
Authors: Oostrom Janneke K. , Born Marise Ph. , Serlie Alec W. , van der Molen Henk T.
Published: June 2011

Advances in computer technology have created opportunities for the development of a multimedia situational test in which responses are filmed with a webcam. This paper examined the relationship of a so-called webcam test with personality, cognitive ability, job experience, and academic performance. Data were collected among 153 psychology students. In line with our expectations, scores on the webcam test, intended to measure interpersonally oriented leadership, were related to extraversion, conscientiousness, emotional stability, and job experience. Furthermore, the webcam tests significantly predicted students’ learning activities during group meetings over and above a cognitive ability test and a personality questionnaire. Overall, this study demonstrates that webcam tests can be a valid complement to traditional predictors in selection contexts.
RNA steady‐state defects in myotonic dystrophy are linked to nuclear exclusion of SHARP
Authors: Dansithong Warunee , Jog Sonali P , Paul Sharan , Mohammadzadeh Robabeh , Tring Stephanie , Kwok Yukwah , Fry Rebecca C , Marjoram Paul , Comai Lucio , Reddy Sita
Published: June 2011

We describe a new mechanism by which CTG tract expansion affects myotonic dystrophy (DM1). Changes to the levels of a panel of RNAs involved in muscle development and function that are downregulated in DM1 are due to aberrant localization of the transcription factor SHARP (SMART/HDAC1‐associated repressor protein). Mislocalization of SHARP in DM1 is consistent with increased CRM1‐mediated export of SHARP to the cytoplasm. A direct link between CTG repeat expression and SHARP mislocalization is demonstrated as expression of expanded CTG repeats in normal cells recapitulates cytoplasmic SHARP localization. These results demonstrate a role for the inactivation of SHARP transcription in DM1 biology.
p53 downregulates Down syndrome‐associated DYRK1A through miR‐1246
Authors: Zhang Yu , Liao Jun‐Ming , Zeng Shelya X , Lu Hua
Published: June 2011

Several microRNAs mediate the functions of p53 family members. Here we characterize miR‐1246 as a new target of this family. In response to DNA damage, p53 induces the expression of miR‐1246 which, in turn, reduces the level of DYRK1A, a Down syndrome‐associated protein kinase. Knockdown of p53 has the opposite effect. Overexpression of miR‐1246 reduces DYRK1A levels and leads to the nuclear retention of NFATc1, a protein substrate of DYRK1A, and the induction of apoptosis, whereas a miR‐1246‐specific inhibitor prevented the nuclear import of NFATc1. Together, these results indicate that p53 inhibits DYRK1A expression through the induction of miR‐1246.
Altered Default Network Activity in Obesity
Authors: Tregellas Jason R. , Wylie Korey P. , Rojas Donald C. , Tanabe Jody , Martin Jesse , Kronberg Eugene , Cordes Dietmar , Cornier Marc‐Andre
Published: June 2011

The regulation of energy intake is a complex process involving the integration of homeostatic signals and both internal and external sensory inputs. To better understand the neurobiology of this process and how it may be dysfunctional in obesity, this study examined activity of the brain's “default network” in reduced‐obese (RO) as compared to lean individuals. The default network is a group of functionally connected brain regions thought to play an important role in internally directed cognitive activity and the interplay between external and internal sensory processing. Functional magnetic resonance imaging was performed in 24 lean and 18 RO individuals in the fasted state after 2 days of eucaloric energy intake and after 2 days of 30% overfeeding in a counterbalanced design. Scanning was performed while subjects passively viewed images of food and nonfood objects. Independent component analysis was used to identify the default network component. In the eucaloric state, greater default network activity was observed in RO compared to lean individuals in the lateral inferior parietal and posterior cingulate cortices. Activity was positively correlated with appetite. Overfeeding resulted in increased default network activity in lean but not RO individuals. These findings suggest that the function of the default network, a major contributor to intrinsic neuronal activity, is altered in obesity and/or obese‐prone individuals. Future studies of the network's function and its relationship to other brain networks may improve our understanding of the mechanisms and treatment of obesity.
Variants at the Endocannabinoid Receptor CB1 Gene (CNR1) and Insulin Sensitivity, Type 2 Diabetes, and Coronary Heart Disease
Authors: de Miguel‐Yanes Jose M. , Manning Alisa K. , Shrader Peter , McAteer Jarred B. , Goel Anuj , Hamsten Anders ,   On Behalf of PROCARDIS, Fox Caroline S. , Florez Jose C. , Dupuis Josée , Meigs James B.
Published: June 2011

Inhibition of the endocannabinoid receptor CB1 improves insulin sensitivity, lowers glycemia, and slows atherosclerosis. We analyzed whether common variants in the gene encoding CB1, CNR1, are associated with insulin resistance, risk of type 2 diabetes (T2D) or coronary heart disease (CHD). We studied 2,411 participants of the Framingham Offspring Study (mean age 60 years, 52% women) for quantitative traits and CHD, and the Framingham SHARe database for T2D risk. We genotyped 19 single‐nucleotide polymorphisms (SNPs) that tagged 85% (at r2 = 0.8) of common (>5%) CNR1 SNPs. Fasting blood glucose and insulin at the 7th (1999–2001) exam were collected. We used age‐, sex‐, BMI‐adjusted models to test additive associations of genotype with homeostasis model assessment of insulin resistance (HOMAIR) (linear mixed‐effect models), T2D, or CHD. To account for multiple tests of SNPs, we generated empirical P values. The C allele at SNP rs806365 (frequency, 57.4%), ∼4.1 kb 3′ from CNR1, was associated with increased HOMAIR (n = 2,261, β = 0.05 per C, empirical P = 0.01), risk of T2D (674 cases, odds ratio = 1.19 per C, nominal P = 0.01) and CHD (237 cases, hazard ratio = 1.23 per C, nominal P = 0.04). The association of rs806365 with HOMAIR was replicated in a meta‐analysis of two independent cohorts (National Health and Nutrition Examination Survey III genetic cohort (NHANES‐III) plus Partners Case‐Control Diabetes Study; 2,540 white individuals, β = 0.037, nominal P = 0.007), but not in the large Meta‐Analyses of Glucose and Insulin‐related traits Consortium (MAGIC) Consortium (n = 29,248, nominal P = 0.74). The association of rs806365 was not replicated either with T2D in Diabetes Genetics Replication and Meta‐analysis (DIAGRAM) (n = 10,128, nominal P = 0.31), or with CHD in PROCARDIS (n = 13,614, nominal P = 0.37). Although supported by initial results, we found no reproducible statistical association of common variation at CNR1 with insulin resistance, T2D, or CHD.
(−)−Epigallocatechin‐3‐gallate Inhibits Pancreatic Lipase and Reduces Body Weight Gain in High Fat‐Fed Obese Mice
Authors: Grove Kimberly A. , Sae‐Tan Sudathip , Kennett Mary J. , Lambert Joshua D.
Published: June 2011

Tea (Camellia sinensis, Theaceae) has been shown to have obesity preventive effects in laboratory studies. We hypothesized that dietary epigallocatechin‐3‐gallate (EGCG) could reverse metabolic syndrome in high fat‐fed obese C57bl/6J mice, and that these effects were related to inhibition of pancreatic lipase (PL). Following treatment with 0.32% EGCG for 6 weeks, a 44% decrease in body weight (BW) gain in high fat‐fed, obese mice (P < 0.01) was observed compared to controls. EGCG treatment increased fecal lipid content by 29.4% (P < 0.05) compared to high fat‐fed control, whereas in vitro, EGCG dose‐dependently inhibited PL (IC50 = 7.5 µmol/l) in a noncompetitive manner with respect to substrate concentration. (−)−Epicatechin‐3‐gallate exhibited similar inhibitory activity, whereas the nonester‐containing (−)−epigallocatechin did not. In conclusion, EGCG supplementation reduced final BW and BW gain in obese mice, and some of these effects may be due to inhibition of PL by EGCG.
Male Inclusion in Randomized Controlled Trials of Lifestyle Weight Loss Interventions
Authors: Pagoto Sherry L. , Schneider Kristin L. , Oleski Jessica L. , Luciani Juliana M. , Bodenlos Jamie S. , Whited Matt C.
Published: June 2011

The prevalence of obesity is similar for men (32.2%) and women (35.5%). It has been assumed that lifestyle weight loss interventions have been developed and tested in predominately female samples, but this has not been systematically investigated. The aim of this review was to investigate total and ethnic male inclusion in randomized controlled trials of lifestyle interventions. PUBMED, MEDLINE, and PSYCHINFO were searched for randomized controlled trials of lifestyle weight loss interventions (N = 244 studies with a total of 95,207 participants) published in the last 10 years (1999–2009). A trial must be in English, included weight loss as an outcome, and tested a dietary, exercise, and/or other behavioral intervention for weight loss. Results revealed samples were on average 27% male vs. 73% female (P < 0.001). Trials recruiting a diseased sample included a larger proportion of males than those not targeting a disease (35% vs. 21%; P < 0.001). About 32% of trials used exclusively female samples, whereas only 5% used exclusively male samples (P < 0.001). No studies in the past 10 years specifically targeted minority males. Ethnic males identified composed 1.8% of total participants in US studies. Only 24% of studies that underrepresented males provided a reason. Males, especially ethnic males, are underrepresented in lifestyle weight loss trials.
Metabolic Syndrome and Acute Hyperglycemia Are Associated With Endoplasmic Reticulum Stress in Human Mononuclear Cells
Authors: Sage Andrew T. , Holtby‐Ottenhof Sarah , Shi Yuanyuan , Damjanovic Suzana , Sharma Arya M. , Werstuck Geoff H.
Published: June 2011

Endoplasmic reticulum (ER) stress and the activation of the unfolded protein response (UPR) have been implicated in a number of complications associated with diabetes mellitus including micro‐ and macrovascular dysfunction. In this study we examine ER stress levels in blood cells isolated from human subjects with metabolic syndrome and in healthy controls. Total RNA and protein were isolated from leukocytes and the levels of specific ER stress markers were quantified by real‐time‐PCR and immunoblot analysis. Our results indicate that, compared to healthy controls, individuals with metabolic syndrome have elevated mRNA levels of genes indicative of ER stress; including spliced XBP‐1 (sXBP‐1), Grp78, and CHOP. Induced ER stress levels correlate with blood glucose but not plasma lipid concentration. Furthermore, in healthy individuals, a standard 75 g oral glucose challenge produced a significant elevation in spliced XBP‐1 (1.3 fold), Grp78 (2.0 fold), and calreticulin (3.5 fold) mRNA 60 min post challenge and a significant increase in Grp78 (2.0 fold), calreticulin (2.7 fold) protein levels 2 h postchallenge, relative to fasting levels. The UPR was also activated ex vivo, in human leukocytes cultured in the presence of 15 mmol/l glucose, supporting a specific role for glucose. The oral glucose challenge was associated with a significant increase in the expression of inflammatory cytokines, including interleukin (IL)‐1α/β, IL‐6, and IL‐8, that may result from ER stress. These findings suggest that there is an association between both acute and chronic dysglycemia and ER stress in humans.
Obesity and Injury‐Related Absenteeism in a Population‐Based Firefighter Cohort
Authors: Poston Walker S.C. , Jitnarin Nattinee , Haddock C. Keith , Jahnke Sara A. , Tuley Brianne C.
Published: June 2011

A consistent relationship has been demonstrated between obesity and absenteeism in the workplace. However, most studies have focused on primarily sedentary occupational groups. Firefighting is a physically demanding profession that involves significant potential for exposure to dangerous situations and strenuous work. No studies to date have evaluated the impact of obesity on risk for absenteeism among firefighters. We examined the cross‐sectional association between BMI and obesity and injury‐related absenteeism. BMI, body fat percentage (BF%), waist circumference (WC), injury, and injury‐related absenteeism were assessed in 478 career male firefighters. One hundred and fifteen firefighters reported an injury in the previous year and the number of days absent from work due to their injury. BMI was an independent predictor of absenteeism due to injury even after adjustment for confounding variables. Firefighters meeting the definition of class II and III obesity had nearly five times (odds ratio (OR) = 4.89; 95% confidence interval (CI) = 3.63–6.58) the number missed work days due to injury when compared to their normal weight counterparts and their elevated risk was greater than firefighters with class I obesity (OR = 2.71; 95% CI = 2.01–3.65) or those who were overweight (OR = 2.55; 95% CI = 1.90–3.41). The attributable per capita costs of class II and III obesity‐related absenteeism over the last year were $1,682.90 per firefighter, $254.00 per firefighter for class I obesity, and $74.41 per firefighter for overweight. Our findings suggest that class II and III obesity were associated with substantial attributable costs to employers and our cost estimates probably underestimate the actual financial burden.
Facilitating Critical Reflections About Disability Among Students in Speech-Language Pathology
Authors: Yu Betty , Epstein Laura
Published: June 2011

Disability scholars argue that it is crucial for clinical professionals to critically examine the dominant and alternative discourses about disability, reflect on their own assumptions about disability, and contemplate the different roles they might take in relation to their patients. To date there are few studies examining how disability is conceptualized by speech-language pathologists (SLPs), or how those ideas affect their approach to working with persons with disabilities. The purpose of this study is to investigate whether shifts in the teaching approaches along medical, social, and experiential continua had an impact on how students in a Communicative Disorders course conceptualized the nature of developmental communicative disorders and the roles of the SLP in working with children with developmental communicative disorders. Reflective essays were collected and analyzed for 22 graduate and 38 undergraduate students in an introductory course on developmental communication disorders where different ways of thinking about disability were introduced over the course of a semester. The findings showed that most students at the start of the class held beliefs that were strongly aligned with the medical model of disability. It also showed that being introduced to different disability frameworks led them to reconceptualize both the notion of developmental communication disorders and SLP roles vis-à-vis children with communication disorders. Finally, the findings highlighted complexities and tensions involved in issues of disability in the clinical context. These results support the need for a systematic infusion and critical examination of disability perspectives in Communicative Disorders curricula.
Comprehensive experimental study of heartbeat oscillations observed under microgravity conditions in the PK-3 Plus laboratory on board the International Space Station
Authors: Heidemann Ralf J. , Couëdel Lénaïc , Zhdanov Sergey K. , Sütterlin K. Robert , Schwabe Mierk , Thomas Hubertus M. , Ivlev Alexey V. , Hagl Tanja , Morfill Gregor E. , Fortov Vladimir E. , Molotkov Vladimir I. , Petrov Oleg F. , Lipaev Andrey I. , Tokarev Valery , Reiter Thomas , Vinogradov Pavel
Published: June 2011

Heartbeat oscillations in complex plasmas with a broad range of fundamental frequencies are observed and studied. The experiments are performed with monodisperse microparticles of different diameters in argon as well as in neon plasmas. The oscillation frequency increases with increasing rf power and neutral gas pressure. At the lower frequencies, oscillations are strongly nonlinear. The microparticle pulsations, the variation of the electrical discharge parameters and the spatially resolved changes in the plasma glow are proven to be strongly correlated. Heartbeat oscillation dynamics is associated with global confinement modes.
The potential role of electric fields and plasma barodiffusion on the inertial confinement fusion database
Authors: Amendt Peter , Wilks S. C. , Bellei C. , Li C. K. , Petrasso R. D.
Published: June 2011

The generation of strong, self-generated electric fields (GV/m) in direct-drive, inertial-confinement-fusion (ICF) capsules has been reported [Rygg et al., Science 319, 1223 (2008); Li et al., Phys. Rev. Lett. 100, 225001 (2008)]. A candidate explanation for the origin of these fields based on charge separation across a plasma shock front was recently proposed [Amendt et al., Plasma Phys. Controlled Fusion 51 124048 (2009)]. The question arises whether such electric fields in imploding capsules can have observable consequences on target performance. Two well-known anomalies come to mind: (1) an observed ≈2× greater-than-expected deficit of neutrons in an equimolar D3He fuel mixture compared with hydrodynamically equivalent D [Rygg et al., Phys. Plasmas 13, 052702 (2006)] and DT [Herrmann et al., Phys. Plasmas 16, 056312 (2009)] fuels, and (2) a similar shortfall of neutrons when trace amounts of argon are mixed with D in indirect-drive implosions [Lindl et al., Phys. Plasmas 11, 339 (2004)]. A new mechanism based on barodiffusion (or pressure gradient-driven diffusion) in a plasma is proposed that incorporates the presence of shock-generated electric fields to explain the reported anomalies. For implosions performed at the Omega laser facility [Boehly et al., Opt. Commun. 133, 495 (1997)], the (low Mach number) return shock has an appreciable scale length over which the lighter D ions can diffuse away from fuel center. The depletion of D fuel is estimated and found to lead to a corresponding reduction in neutrons, consistent with the anomalies observed in experiments for both argon-doped D fuels and D3He equimolar mixtures. The reverse diffusional flux of the heavier ions toward fuel center also increases the pressure from a concomitant increase in electron number density, resulting in lower stagnation pressures and larger imploded cores in agreement with gated, self-emission, x-ray imaging data.
Direct laser acceleration of electron by an ultra intense and short-pulsed laser in under-dense plasma
Authors: Li Y. Y. , Gu Y. J. , Zhu Z. , Li X. F. , Ban H. Y. , Kong Q. , Kawata S.
Published: June 2011

Direct laser acceleration (DLA) of electron by an ultra intense and short-pulsed laser interacting with under-dense plasma is investigated based on 2.5-dimensional particle-in-cell simulation. A high-density electron beam is generated by the laser longitudinal ponderomotive force. Although the total number of DLA electrons is significantly smaller than the number of electrons trapped in the bubble, the total charge of high-energy DLA electrons (E>800MeV) reaches 67 pC/μm. It is found that the electron beam occurs in a two-stage acceleration, i.e., accelerated in vacuum by the laser directly soon after a DLA process in plasma. The beam is accelerated violently with effective acceleration gradient in 100 GeV/cm. The energy spectrum of electrons presents a Maxwellian distribution with the highest energy of about 3.1 GeV. The dependence of maximum electron energy and electric quantity with laser intensity, laser width, pulse duration, and initial plasma density are also studied.
Excitations in doped quantum dot driven by periodically fluctuating impurity domain
Authors: Chatterjee Kashinath , Kr Datta Nirmal , Ghosh Manas
Published: June 2011

We explore the excitation profile of a repulsive impurity doped quantum dot induced by a periodically fluctuating impurity domain. We have considered Gaussian impurity centers. The investigation reveals the effects of the dopant coordinate and dopant strength in conjunction with the oscillating impurity domain to modulate the excitation pattern. The investigation also reveals the maximization in the excitation rate for some typical range of values of dopant location and dopant strength.
Solar to electrical conversion via liquid crystal elastomers
Authors: Hiscock T. , Warner M. , Palffy-Muhoray P.
Published: June 2011

We have constructed a hypothetical charge pump which converts solar energy into DC electricity. The output is generated by cyclic changes in the capacitance of a circuit, which transfers charge from a low to a high voltage. The electric field across the capacitor must be of the order of 108Vm-1 to compete with efficiencies of photovoltaics. We have modeled the output using a liquid crystal elastomer as the working substance. Efficiencies of 1-4% are obtained, and are enhanced by careful choices in the capacitor geometries and the operating voltages of the charge pump.
Temperature and frequency characteristics of low-loss MnZn ferrite in a wide temperature range
Authors: Sun Ke , Lan Zhongwen , Yu Zhong , Xu Zhiyong , Jiang Xiaona , Wang Zihui , Liu Zhi , Luo Ming
Published: June 2011

A low-loss Mn0.7Zn0.24Fe2.06O4 ferrite has been prepared by a solid-state reaction method. The MnZn ferrite has a high initial permeability, μi (3097), a high saturation induction, Bs (526 mT), a high Curie temperature, Tc (220 °C), and a low core loss, PL (≤ 415 kW/m3) in a wide temperature (25–120 °C) and frequency (10–100 kHz) range. As the temperature increases, an initial decrease followed by a subsequent increase of hysteresis loss, Ph, and eddy current loss, Pe is observed. Both Ph and Pe increase with increasing frequency. When f ≥ 300 kHz, a residual loss, Pr, appears. Pe increases with increasing temperature and frequency. The temperature and frequency dependence of Ph can be explained by irreversible domain wall movements, Pe by the skin effect, and Pr by domain wall resonance, respectively.
Anomalous Hall effect behavior in (100) and (110) CrO2 thin films
Authors: Sato H. , Pathak M. , Mazumdar D. , Zhang X. , Mankey G. J. , LeClair P. , Gupta A.
Published: June 2011

First and second order magnetic anisotropy constants have been determined in (110) and (100) CrO2 films using magnetometry and anomalous Hall effect measurements. Higher in-plane anisotropy is observed in strain-free (110) CrO2 films as compared to strained (100) CrO2 films, while out-of-plane magnetic anisotropy (OPMA) is stronger in (100) films. Temperature-dependent OPMA is particularly striking for (110) films with a sharp drop below 200 K, whereas for (100) films the anisotropy increases as the temperature decreases. These results are consistent with changes in the magnetization orientation with decreasing temperature, possibly caused by differences in the thermal expansion coefficient between the substrate and film.
Cu and Co codoping effects on room-temperature ferromagnetism of (Co,Cu):ZnO dilute magnetic semiconductors
Authors: Hu Fengchun , Liu Qinghua , Sun Zhihu , Yao Tao , Pan Zhiyun , Li Yuanyuan , He Jingfu , He Bo , Xie Zhi , Yan Wensheng , Wei Shiqiang
Published: June 2011

Homogeneous distribution of magnetic dopants in semiconductor hosts is highly desired for practical applications in spintronics. Herein, we show that codoping 2 at. % Cu with Zn0.98Co0.02O could change the magnetic behavior from paramagnetism to room temperature ferromagnetism. For Zn0.96Cu0.02Co0.02O nanocrystals prepared by a modified solid-state reaction method, the combination of x-ray absorption fine structure spectra at Co, Cu, and O K-edge reveals that the Cu and Co ions are substitutionally incorporated into the ZnO matrix and distribute randomly in the host. First-principles calculations further indicate strong hybridization between Co 3d states and Cu-induced donor impurity bands at the Fermi level, which effectively enhances the indirect ferromagnetic superexchange of Co ions and is responsible for the occurrence of ferromagnetism in (Co,Cu)-codoped ZnO.
Modeling of solvent evaporation from polymer jets in electrospinning
Authors: Wu Xiang-Fa , Salkovskiy Yury , Dzenis Yuris A.
Published: June 2011

Solvent evaporation plays a critical role in nanofiber formation in electrospinning. Here, we present a nonlinear mass diffusion-transfer model describing the drying process in dilute polymer solution jets. The model is used to predict transient solvent concentration profiles in polyacrylonitrile/N,N-dimethylformamide (PAN/DMF) jets with the initial radii ranging from 50 μm down to 100 nm. Numerical simulations demonstrate high transient inhomogeneity of solvent concentration over the jet cross-section in microscopic jets. The degree of inhomogeneity decreases for finer, submicron jets. The simulated jet drying time decreases rapidly with the decreasing initial jet radius, from seconds for microjets to single milliseconds for nanojets. The results demonstrate the need for further improved coupled multiphysics models of electrospinning jets.
Epitaxial growth of Bi2Se3 topological insulator thin films on Si (111)
Authors: He Liang , Xiu Faxian , Wang Yong , Fedorov Alexei V. , Huang Guan , Kou Xufeng , Lang Murong , Beyermann Ward P. , Zou Jin , Wang Kang L.
Published: June 2011

In this paper, we report the epitaxial growth of Bi2Se3 thin films on Si (111) substrate, using molecular beam epitaxy (MBE). We show that the as-grown samples have good crystalline quality, and their surfaces exhibit terracelike quintuple layers. Angel-resolved photoemission experiments demonstrate single-Dirac-conelike surface states. These results combined with the temperature- and thickness-dependent magneto-transport measurements, suggest the presence of a shallow impurity band. Below a critical temperature of ∼100K, the surface states of a 7 nm thick film contribute up to 50% of the total conduction.
Inter-ion coulomb interactions in a magneto-optical trap ion source
Authors: Steele A. V. , Knuffman B. , McClelland J. J.
Published: June 2011

We have investigated the role played by inter-ion Coulomb interactions in a magneto-optical trap ion source (MOTIS). Using a Monte Carlo simulation accounting for all pair-wise ion-ion Coulomb interactions in the source, we have calculated the broadening of the transverse spatial and velocity distributions as well as the increase in emittance over a range of beam currents and extraction electric fields. Using a 7Li MOTIS, we have experimentally studied the broadening of the spatial distribution as a function of total beam current and extraction electric field by measuring the fraction of the beam current that passes through a 20 μm diameter aperture. The Monte Carlo simulations agree well with the experimental results, indicating that such simulations capture the essential physics of the source. Our results show that while Coulomb interactions can cause a significant increase in emittance in some situations, it is possible to keep the effects to an acceptable level by suitable choice of extraction field and beam current. These considerations are essential to the process of optimizing MOTIS geometry and operating conditions for use in high-resolution focused ion beam applications.
Two-dimensional synthetic-aperture focusing technique in photoacoustic microscopy
Authors: Deng Zilin , Yang Xiaoquan , Gong Hui , Luo Qingming
Published: June 2011

Angiogenesis plays an important role in tumor growth and expansion, which makes it one of the most critical subjects in oncologic research. Angiogenesis can be imaged with photoacoustic microscopy (PAM), however the lateral resolution deteriorates significantly out of focus. Virtual-point-detector-based synthetic aperture focusing technique (SAFT) combined with the coherence weighting factor (CF) can alleviate the blurring, at a cost of anisotropy of resolution. In this study, a two-dimensional SAFT with CF was investigated to improve resolution and yield lateral resolution isotropy simultaneously. In a phantom study, two carbon fibers with a diameter of 6 μm fixed perpendicularly to each other were imaged with PAM developed in our laboratory. In the depth range of 0.6 mm near the focal spot, the best resolution processed with one-dimensional (1D) SAFT is 40 μm better than that processed with two-dimensional (2D) SAFT. However, the maximum difference in lateral resolution between the z-x and z-y planes is about 15 μm processed with 2D SAFT, while it is 145 μm processed with 1D SAFT. Furthermore, the 2D SAFT increased the signal-to-noise ratio (SNR) by up to 8 dB higher than 1D SAFT at an imaging depth of 700 μm below the focal spot. Finally, in vivo imaging of the dorsal subcutaneous microvasculature of a mouse was used to validate the improved performance of 2D SAFT.
Electrodynamic force of dielectric barrier discharge
Authors: Shang J. S. , Roveda F. , Huang P. G.
Published: June 2011

The periodic electrostatic force of dielectric barrier discharge (DBD) in nitrogen for flow control is investigated by a system of physics-based, two-dimensional model equations. The plasma generation process of DBD is mainly the avalanche growth of electrons through the secondary emission from cathode. Therefore, the charged particle motion of a succession of random micro discharges can be approximated by the drift-diffusion model. The force of DBD generated by charge separation and accumulation over the dielectrics is obtained by solving the model equations with the rigorous media interface boundary condition of Maxwell equations in the time domain. The discharge structure and force components by different electrical permittivity and amplitudes of externally applied electrical potential are delineated and quantified.
Effect of annealing on the structural and luminescent properties of ZnO nanorod arrays grown at low temperature
Authors: Shi Shaobo , Xu Jianping , Zhang Xiaosong , Li Lan
Published: June 2011

Vertically well-aligned ZnO nanorod arrays were synthesized on glass substrates by a two-step chemical bath deposition method. The structural and luminescent properties of as-grown and air annealed samples were investigated. Scanning electron microscopy, x-ray diffraction and Raman spectra demonstrate that ZnO nanorods are well oriented with c-axis perpendicular to the substrates. Photoluminescence spectra show a weak ultraviolet emission and an intense broad visible emission band for as-grown and air annealed samples. These visible emission bands exhibit dependences of post annealing temperatures and excitation energies: (1) as the annealing temperature increases, the visible emission band gradually red-shifts from yellow to orange-red; (2) the optimal excitation energy for yellow and orange-red emission band is near the band-gap energy; (3) green emission band can be excited only by the energies lower than the band-gap energy and this emission becomes weak after high temperature annealing. A depletion region model is presented to explain the origins and red-shift of the visible emission bands. The recombination of a delocalized electron in the interstitial zinc close to the conduction band with a deeply trapped hole in the single negatively charged interstitial oxygen center in the deletion region (in the bulk) is responsible for the yellow (orange-red) emission.
Self-suppression of double tearing modes via Alfvén resonance in rotating tokamak plasmas
Authors: Wang Zheng-Xiong , Wei Lai , Wang Xiaogang , Liu Yue
Published: June 2011

Reversed magnetic shear configuration, a key method for improving plasma confinement in advanced tokamaks, is prone to exciting double tearing modes (DTMs) that can severely degrade the plasma confinement. In this letter, we reveal a new mechanism of suppressing the DTM instability due to the self-induced Alfvén resonance in rotating tokamak plasmas. The linear growth rate is reduced from ~SHp-1/3 of the fast DTM regime to ~SHp-3/5 of the slow single tearing mode regime, where SHp is magnetic Reynolds number. Instead of generating magnetic islands at the inner rational surface that can greatly enhance plasma transport in the core region, the formation of current sheets at resonance layers not only prevents the fast nonlinear DTM reconnection phase but also contributes to plasma heating.
ITG sideband coupling models for zonal flows
Authors: Stransky M.
Published: June 2011

Four-wave interaction model between ITG mode and zonal flow was derived using fluid equations. In this model, the zonal flow is excited non-linearly by ITG turbulence via Reynolds stress. Numerical simulations show that the system allows for a small range above the ITG threshold where the zonal flow can stabilize an unstable ITG mode, effectively increasing ηi threshold, an effect which has been called the Dimits shift. However, the shift is smaller than in known cases such that in the Cyclone base.
Electronic and optical switching of solution-phase deposited SnSe2 phase change memory material
Authors: Wang Robert Y. , Caldwell Marissa A. , Jeyasingh Rakesh Gnana David , Aloni Shaul , Shelby Robert M. , Wong H.-S. Philip , Milliron Delia J.
Published: June 2011

We report the use of chalcogenidometallate clusters as a solution-processable precursor to SnSe2 for phase change memory applications. This precursor is spin-coated onto substrates and then thermally decomposed into a crystalline SnSe2 film. Laser testing of our SnSe2 films indicate very fast recrystallization times of 20 ns. We also fabricate simple planar SnSe2 electronic switching devices that demonstrate switching between ON and OFF resistance states with resistance ratios varying from 7−76. The simple cell design resulted in poor cycling endurance. To demonstrate the precursor’s applicability to advanced via-geometry memory devices, we use the precursor to create void-free SnSe2 structures inside nanowells of ∼25 nm in diameter and ∼40 nm in depth.
Tailored magnetic anisotropy in an amorphous trilayer
Authors: Fu Yu , Barsukov I. , Raanaei H. , Spasova M. , Lindner J. , Meckenstock R. , Farle M. , Hjörvarsson B.
Published: June 2011

An amorphous Co68Fe24Zr8(3 nm)/Al70Zr30(3 nm)/Co68Fe24Zr8(3 nm) trilayer system has been investigated using in-plane and out-of-plane angular dependent ferromagnetic resonance at different frequencies. The in-plane magnetic anisotropy is uniaxial, retaining its value of (2.9 ± 0.1) × 103 J/m3 for each magnetic layer, whereas its direction was tailored independently in an arbitrary manner by applying an external magnetic field during the film deposition. The perpendicular anisotropy constant, supposed to reflect the interface quality, is nearly identical for both layers. Furthermore, the magnetic layers act independently upon each other due to the absence of interlayer coupling.
Raman spectroscopic study of Na1/2Bi1/2TiO3-x%BaTiO3 single crystals as a function of temperature and composition
Authors: Luo Liang , Ge Wenwei , Li Jiefang , Viehland D. , Farley Charles , Bodnar Robert , Zhang Qinhui , Luo Haosu
Published: June 2011

A Raman spectroscopic study of Na1/2Bi1/2TiO3-x%BaTiO3 (NBT-x%BT) single crystals with x = 0 and 5.6 has been performed as a function of temperature from 25 to 600 °C. The general features of the Raman spectra for the various compositions were similar over the region of the phase diagram investigated, with only subtle changes between rhombohedral (R), tetragonal (T) and cubic phases. The peaks were broad, with no significant narrowing on cooling through a phase transition. We find evidence of an oxygen octahedral rotational mode in the paraelectric state. On cooling near and below the ferroelectric Curie temperature, a gradual change in intensity of the A-O and B-O peaks occurred with decreasing temperature. Evidence of a ferroelectric → antiferroelectric transition was found near 200–250 °C, consistent with the onset of dispersion in the dielectric constant. The phase transition mechanism was discussed. The findings indicate the presence of a broad distribution of quasistatic local structural distortions, which only have subtle differences in the various average structures.