bluuebunny/crossref_metadata_2025_split huggingface dataset:
Factorization of the Fourier transform of the pressure‐Poisson equation using finite differences in colocated grids
Authors: Mellado J.P. , Ansorge C. 
Published: February 2012

AbstractThe zero‐divergence constraint on the velocity field in the numerical simulation of incompressible flows can be reduced, in certain cases, to a set of one‐dimensional linear difference equations for the pressure. These equations involve the second‐order derivative δxδxp expressed in terms of twice the first‐order derivative. When implicit finite‐difference schemes are used, those equations lead to full linear systems, which are computationally prohibitive. Hence, it is a common practice to substitute δxδxp by a different discretization δxxp. However, it is well known that this step results in a non‐zero divergence in the velocity field. This paper presents a factorization of the original equation that allows to satisfy the discrete solenoidal constraint exactly while maintaining a linear relation between the number of operations and the grid size. As an example, the method is particularized to compact schemes often found in the literature.
Biocatalytic conversion of aloeresin A to aloesin
Authors: Steenkamp Lucia , Mathiba Kgama , Steenkamp Paul , Phehane Vuyisile , Mitra Robin , Heggie Steven , Brady Dean 
Published: February 2012

Abstract
Leaf exudates from Aloe species, such as the Southern African Aloe ferox, are used in traditional medicines for both humans and livestock. This includes aloesin, a skin bleaching product that inhibits the synthesis of melanin. Aloesin, (a C-glycoside-5-methylchromone) can be released from aloeresin A, an ester of aloesin, through hydrolysis. The objective of the current study was to identify an enzymatic hydrolysis method for converting aloeresin A to aloesin, resulting in increased concentrations of aloesin in the aloe bitters extract. More than 70 commercially available hydrolytic enzymes were screened for the conversion of aloeresin A. An esterase (ESL001-02) from Diversa, a lipase (Novozym 388) and a protease (Aspergillus oryzae) preparation were identified during screening as being capable of providing conversion of pure aloeresin A, with the protease giving the best conversion (~100%). It was found that a contaminating enzyme in Novo 388 was responsible for the conversion of aloeresin A to aloesin. This contaminating enzyme, possibly a protease, was able to give almost complete conversion using crude aloe bitters extract, doubling the concentration of aloesin in aloe bitters extract via the hydrolysis of aloeresin A.
A National Evaluation of Community‐Based Youth Cessation Programs: End of Program and Twelve‐Month Outcomes
Authors: Curry Susan J. , Mermelstein Robin J. , Emery Sherry L. , Sporer Amy K. , Berbaum Michael L. , Campbell Richard T. , Flay Brian , Warnecke Richard B. 
Published: February 2012

AbstractMost youth cessation treatment research consists of efficacy studies in which treatments are evaluated under optimal conditions of delivery. Less is known about the effectiveness of youth cessation treatments delivered in real‐world, community based settings. A national sample of 41 community‐based youth cessation programs participated in a longitudinal evaluation to identify site, program, and participant characteristics associated with successful cessation. Validated quit rates were comparable to those in randomized controlled trials; 7‐day abstinence at the end of program averaged 14% and 30‐day abstinence at 12 months averaged 12%. Multivariate GEE models explored predictors of smoking cessation at the end of the programs and at 12 months. Results showed correlates of both short‐ and long‐term cessation. Findings point to the importance of both individual and community‐level variables, including motivation, opportunities for and encouragement to engage in activities outside of academics, having youth participate in treatment before they become highly dependent smokers, and community norms and ordinances that discourage youth purchase, use and possession of tobacco. Providing evidence‐based treatment to youth in community‐based settings results in successful cessation.
Investment and employment from large-scale photovoltaics up to 2050
Authors: Grossmann Wolf , Steininger Karl W. , Schmid Christoph , Grossmann Iris 
Published: February 2012

Abstract
Investments in renewable energy were at US$211 billion in 2010 and developing economies overtook developed ones for the first time in terms of new financial investments in renewable energy. Photovoltaics for generation of electricity from sunlight has the highest growth rate among the competing forms of renewable energy and has now begun to achieve grid parity in some regions. If these trends of investments continue, solar energy will play a major economic role. We analyze these developments and assess the ensuing amounts of investment and employment for a range of sizes of the sector of solar energy. We find that by 2050 electricity from photovoltaics could cover up to 90% of total global energy demand, with a then global capital investment in our main scenario in photovoltaic manufacturing capacity at 500 billion US$2010 by around 2030 and 1,500 billion by 2050. Employment in photovoltaic manufacturing is predicted to rise to 6 million by 2050. Sensitivity analysis with respect to the core parameters of assumptions is supplied.
On the reliability and availability of replicated and rejuvenating systems under stealth attacks and intrusions
Authors: Teixeira d’Aguiar Norton Brandão Luís , Neves Bessani Alysson 
Published: February 2012

Abstract
This paper considers the estimation of reliability and availability of intrusion-tolerant systems subject to non-detectable intrusions caused by stealth attacks. We observe that typical intrusion tolerance techniques may in certain circumstances worsen the dependability properties they were meant to improve. We model intrusions as a probabilistic effect of adversarial efforts and analyze different strategies of attack and rejuvenation. We compare several configurations of intrusion-tolerant replication and proactive rejuvenation, and varying mission times and expected times to node-intrusion. In doing so, we identify thresholds that distinguish between improvement and degradation of dependability, with a focus on security. We highlight the complementarity of replication and rejuvenation, showing improvements of resilience not attainable with any of the techniques alone, but possible when they are combined. We advocate the need for thorougher system models, by showing vulnerabilities arising from incomplete specifications.
Petrogenesis and tectonic significance of the Late Permian–Middle Triassic calc-alkaline granites in the Balong region, eastern Kunlun Orogen, China
Authors: ZHANG JIN-YANG , MA CHANG-QIAN , XIONG FU-HAO , LIU BIN 
Published: February 2012

AbstractNumerous calc-alkaline granitoid intrusions in the eastern Kunlun Orogen provide a valuable opportunity to constrain the evolution of the orogen. The age and genesis of these intrusions, however, remain poorly understood. The granitoid intrusions near the Balong region, eastern Kunlun Orogen, consist of granodiorite, diorite and syenogranite. The granodiorite contains crystallized segregations, abundant mafic microgranular enclaves (MMEs) and small quartz diorite stocks. In situ zircon U–Pb dating reveals that the granodiorites and quartz diorites were emplaced between 263 and 241 Ma, whereas the syenogranite was produced at c. 231 Ma. The granodiorite and quartz diorite have a calc-alkaline affinity and are metaluminous and Na-rich, with slightly enriched Sr–Nd isotope compositions. The granodiorite is characterized by fractionated REE patterns, whereas the quartz diorite displays a relatively flat REE pattern. The MMEs are consistent with the granodiorite in terms of incompatible elements and Sr–Nd isotope composition. Compared to the granodiorite and diorite, the syenogranite has higher SiO2, K, Rb, Th and Sr contents and a lower Rb/Sr ratio. The results presented here, when combined with regional geological data, indicate that the granodiorite and quartz diorite were derived from dehydration melting of mafic lower crustal rocks during the N-directed subduction of the Anyemaqen ocean lithosphere in Late Permian–Middle Triassic times, whereas the syenogranite was produced at a higher crustal level in a syn-collisional setting compared to the granodiorite.
Simulations of efficient laser wakefield accelerators from 1 to 100GeV
Authors: TZOUFRAS M. , HUANG C. , COOLEY J. H. , TSUNG F. S. , VIEIRA J. , MORI W. B. 
Published: February 2012

AbstractOptimization of laser wakefield acceleration involves understanding and control of the laser evolution in tenuous plasmas, the response of the plasma medium, and its effect on the accelerating particles. We explore these phenomena in the weakly nonlinear regime, in which the laser power is similar to the critical power for self-focusing. Using Particle-In-Cell simulations with the code QuickPIC, we demonstrate that a laser pulse can remain focused in a plasma channel for hundreds of Rayleigh lengths and efficiently accelerate a high-quality electron beam to 100GeV (25GeV) in a single stage with average gradient 3.6GV/m (7.2GV/m).
The British Imperial Antarctic Expedition 1920–1922: Paradise Harbour, Antarctic Peninsula
Authors: Harrowfield David L. 
Published: February 2012

ABSTRACTOn 12 January 1921 the British Imperial Antarctic Expedition 1920–1922 led by 27 year old Cambridge graduate John Lachlan Cope, arrived at Paradise Harbour situated west of Andvord Bay on the Danco Coast, Graham Land. The four-man party was landed by Norwegian whalers, on a small island with a promontory they named ‘Water-boat Point’ now Waterboat Point (64°49’S, 62°52’E), because of an abandoned water-boat there. Fortunately ready accommodation was available in the boat and to this were attached cases of provisions to form an improvised hut with an extension added before winter. Cope and Wilkins his deputy leader stayed just six weeks and after helping to build the hut, in effect abandoned the other two members of the expedition, Bagshawe and Lester. The two men voluntarily remained and in the belief that they would be paid, vigorously pursued a varied scientific programme. Although lacking essential items including certain scientific instruments, they were comparatively well off until relieved by Norwegian whalers in January 1922. The expedition that lasted one year and a day and was supported logistically by Norwegian whalers, became the smallest British expedition to overwinter in Antarctica and was the only expedition at that time. Bagshawe and Lester produced an impressive record of observations in meteorology, biology, oceanography, glaciology, botany and geology. In 1951 when Chile established Presidente González Videla Station, remains of the water-boat and hut were present, but today little evidence remains of the site destroyed by natural processes, human intervention and buried by guano. With exception of a few papers and chapters in books,Two men in the Antarctic(Bagshawe 1939) remains the definitive work on this generally forgotten expedition. For this paper primary resources have focused on original manuscripts. Although much material including financial records if indeed they existed, has been lost, surviving documents provide insights into the expedition. Reasons for the eventual loss of Bagshawe and Lester's field station are discussed.
Unequal Social Engagement for Older Adults: Constraints on Choice
Authors: Rozanova Julia , Keating Norah , Eales Jacquie 
Published: February 2012

RÉSUMÉBien que les associations positives entre l’engagement et le bien-être social dans la vie ultérieure ont été confirmées par certaines études, cette étude visait à comprendre pourquoi certaines personnes ainées ne peuvent pas être impliquées. Les auteurs ont analysé des expériences vécues de 89 ainés demeurant dans trois communautés rurales au Canada, raconté dans les entrevues demi-structuré, utilisant la méthode de comparaison constante. Cinq facteurs font des choix pour l’engagement social dans la vie ultérieure inégale parmi les personnes ainées qui diffèrent par le sexe, la classe, l’âge, et le statut de santé. L’engagement profond dans le travail de soin, l’altruisme obligatoire, les ressources personnelles, les occasions d’implication perçues objectivement et subjectivement disponibles, et les barrières ageistes autour des activités désirées comme le travail contraignent des choix pour les aînés qui manquent le privilège dans l’économie du marché, notamment pour les vieilles femmes à faibles revenus. Pour éviter nuire et stigmatiser les plus vieilles personnes vulnérables, les barrières sociales aux activités significatives doivent être abordées – par exemple, par la provision de sécurité de revenu ou renversant la discrimination en raison de l’âge dans l’accès au marché du travail.
A compiled implementation of normalisation by evaluation
Authors: AEHLIG KLAUS , HAFTMANN FLORIAN , NIPKOW TOBIAS 
Published: February 2012

AbstractWe present a novel compiled approach to Normalisation by Evaluation (NBE) for ML-like languages. It supports efficient normalisation of open λ-terms with respect to β-reduction and rewrite rules. We have implemented NBE and show both a detailed formal model of our implementation and its verification in Isabelle. Finally we discuss how NBE is turned into a proof rule in Isabelle.
Disgust in Bioethics
Authors: SALLES ARLEEN , DE MELO-MARTIN INMACULADA 
Published: February 2012

“Dissecting Bioethics,” edited by Tuija Takala and Matti Häyry, welcomes contributions on the conceptual and theoretical dimensions of bioethics.The section is dedicated to the idea that words defined by bioethicists and others should not be allowed to imprison people’s actual concerns, emotions, and thoughts. Papers that expose the many meanings of a concept, describe the different readings of a moral doctrine, or provide an alternative angle to seemingly self-evident issues are therefore particularly appreciated.The themes covered in the section so far include dignity, naturalness, public interest, community, disability, autonomy, parity of reasoning, symbolic appeals, and toleration.All submitted papers are peer reviewed. To submit a paper or to discuss a suitable topic, contact Tuija Takala attuija.takala@helsinki.fi.
The Density Turán Problem
Authors: CSIKVÁRI PÉTER , NAGY ZOLTÁN LÓRÁNT 
Published: February 2012

LetHbe a graph onnvertices and let the blow-up graphG[H] be defined as follows. We replace each vertexviofHby a clusterAiand connect some pairs of vertices ofAiandAjif (vi,vj) is an edge of the graphH. As usual, we define the edge density betweenAiandAjasWe study the following problem. Given densities γijfor each edge (i,j) ∈E(H), one has to decide whether there exists a blow-up graphG[H], with edge densities at least γij, such that one cannot choose a vertex from each cluster, so that the obtained graph is isomorphic toH,i.e., noHappears as a transversal inG[H]. We calldcrit(H) the maximal value for which there exists a blow-up graphG[H] with edge densitiesd(Ai,Aj)=dcrit(H) ((vi,vj) ∈E(H)) not containingHin the above sense. Our main goal is to determine the critical edge density and to characterize the extremal graphs.First, in the case of treeTwe give an efficient algorithm to decide whether a given set of edge densities ensures the existence of a transversalTin the blow-up graph. Then we give general bounds ondcrit(H) in terms of the maximal degree. In connection with the extremal structure, the so-called star decomposition is proved to give the best construction forH-transversal-free blow-up graphs for several graph classes. Our approach applies algebraic graph-theoretical, combinatorial and probabilistic tools.
Associations of home food availability, dietary intake, screen time and physical activity with BMI in young American-Indian children
Authors: Arcan Chrisa , Hannan Peter J , Fulkerson Jayne A , Himes John H , Rock Bonnie Holy , Smyth Mary , Story Mary 
Published: February 2012

AbstractObjectiveTo evaluate associations between home environmental factors and BMI of young American-Indian children.DesignCross-sectional and prospective study.SettingSchool-based obesity prevention trial (Bright Start) on a Northern Plains Indian reservation in South Dakota. Mixed model multivariable analysis was used to examine associations between child BMI categories (normal, overweight and obese) and home food availability, children's dietary intake and physical activity. Analyses were adjusted for age, gender, socio-economic status, parent BMI and school; prospective analyses also adjusted for study condition and baseline predictor and outcome variables.SubjectsKindergarten children (n 424, 51 % male; mean age = 5·8 years, 30 % overweight/obese) and parents/caregivers (89 % female; 86 % overweight/obese) had their height and weight measured and parents/caregivers completed surveys on home environmental factors (baseline and 2 years later).ResultsHigher fast-food intake and parent-perceived barriers to physical activity were marginally associated with higher probabilities of a child being overweight and obese. Vegetable availability was marginally associated with lower probabilities of being overweight and obese. The associations between home environmental factors and child weight status at follow-up were not significant.ConclusionsFindings indicate that selected aspects of the home environment are associated with weight status of American-Indian children. Obesity interventions with this population should consider helping parents to engage and model healthful behaviours and to increase availability of healthful foods at home.
Radio Aurora Explorer: Mission science and radar system
Authors: Bahcivan H. , Cutler J. W. 
Published: February 2012

The Radio Aurora Explorer (RAX) satellite is the first of several satellites funded under the NSF CubeSat‐based Space Weather and Atmospheric Research Program. RAX is a ground‐to‐space bi‐static radar remote sensing experiment designed to measure and understand the causes of meter‐scale ionospheric irregularities. Also known as field‐aligned irregularities (FAI), such non‐thermal, coherent fluctuations of electron density occur in response to strong ionospheric flows or plasma density gradients during geomagnetic disturbances and are considered a space weather concern due to disruption to communication and navigation signals. The RAX CubeSat was launched in November 2010 and conducted a single experiment in coordination with the Poker Flat Incoherent Scatter Radar. Due to geophysical inactivity, e.g., lack of strong ionospheric electric fields and low ionospheric densities, no FAI were expected or observed. However, the radar receiver payload operation was successfully demonstrated, including the capability to sense signals as low as −110 dBm, the capability of transmitter–receiver synchronization and accurate ranging, processing of 1.2 GB of raw radar data on board in less than 1 hour, and the downlink of the science results within three–four passes. Analysis of the payload data shows that the noise level is sufficiently low. Although the interference level is a concern, it does not appear to significantly limit the measurements. Toward the end of December 2010, the solar power system gradually degraded and the mission terminated in early February 2011 after prolonged loss of contact with the satellite. Meanwhile, RAX II was launched in October 2011 to a polar orbit. This paper describes the RAX science and radar system and presents the results from the first experiment conducted.
Contrasting Maturation and Growth of Northern Rock Sole in the Eastern Bering Sea and Gulf of Alaska for the Purpose of Stock Management
Authors: Stark James W. 
Published: February 2012

Abstract
The primary purpose of this study was to provide commercial fishery managers with the age- and length-at-maturity information about northern rock sole Lepidopsetta polyxystra needed for them to set a sustainable overfishing limit and evaluate the precision of the two predictors of maturity. The estimated length at which 50% of eastern Bering Sea female northern rock sole matured (L 50) was 309 mm, which was significantly smaller than that for Gulf of Alaska females. We determined that the differences in L 50 between populations were probably the result of differences in the rate of female growth. Growth was significantly faster in the Gulf of Alaska than in the eastern Bering Sea during 1996 and 1999. However, by 2007 the growth rates were similar between these areas. The variability in growth was correlated with seawater temperature. There were also differences in the age at which 50% of the females matured (A 50) between the populations in the eastern Bering Sea (9 years) and the Gulf of Alaska (7 years). In contrast, within the eastern Bering Sea, females maintained a similar A 50 over several years, which indicates that age is the most reliable predictor of maturity for northern rock sole.
Received April 8, 2011; accepted August 11, 2011
A Method to Train Groups of Predator-Naive Fish to Recognize and Respond to Predators When Released into the Natural Environment
Authors: Olson Justin A. , Olson Jenae M. , Walsh Rachel E. , Wisenden Brian D. 
Published: February 2012

Abstract
Hatcheries are effective at producing large numbers of fish for augmenting fisheries or conserving endangered populations, but the fish they produce are often predator-naive, resulting in high levels of predation mortality when the fish are first released into natural water bodies. Fish normally acquire recognition of novel stimuli as indicators of danger when injury-released chemical cues from conspecifics (a known indicator of an actively foraging predator) are presented simultaneously with a novel stimulus (e.g., predator odor, image). Thus, fish in wild populations quickly learn the sight and smell of their predators. Past research has demonstrated that predator-naive, hatchery-reared fish can be trained to recognize predators and that fish trained by this method have a significantly greater probability of surviving an encounter with a predator. To implement predator training in fishery management, predator recognition training must be feasible on a large scale in a way that does not place an undue financial or logistical burden on fisheries managers. Here, we demonstrate that groups of fish can be quickly and easily conditioned to recognize the odor of a novel predator and react to it with antipredator behavior. This simple method could improve the cost effectiveness of any stocking program, result in greater densities of managed stocks, and enhance the direct and indirect economic benefits of a fishery.
Received April 21, 2011; accepted October 11, 2011