bluuebunny/crossref_metadata_2025_split huggingface dataset:
Empirical hardness models
Authors: Leyton-Brown Kevin , Nudelman Eugene , Shoham Yoav 
Published: June 2009

Is it possible to predict how long an algorithm will take to solve a previously-unseen instance of an NP-complete problem? If so, what uses can be found for models that make such predictions? This article provides answers to these questions and evaluates the answers experimentally.
We propose the use of supervised machine learning to build models that predict an algorithm's runtime given a problem instance. We discuss the construction of these models and describe techniques for interpreting them to gain understanding of the characteristics that cause instances to be hard or easy. We also present two applications of our models: building algorithm portfolios that outperform their constituent algorithms, and generating test distributions that emphasize hard problems.
We demonstrate the effectiveness of our techniques in a case study of the combinatorial auction winner determination problem. Our experimental results show that we can build very accurate models of an algorithm's running time, interpret our models, build an algorithm portfolio that strongly outperforms the best single algorithm, and tune a standard benchmark suite to generate much harder problem instances.
Efficient reasoning about a robust XML key fragment
Authors: Hartmann Sven , Link Sebastian 
Published: June 2009

We review key constraints in the context of XML as introduced by Buneman et al. We demonstrate that:
(1) one of the proposed inference rules is not sound in general, and
(2) the inference rules are incomplete for XML key implication, even for nonempty sets of simple key paths.
This shows, in contrast to earlier statements, that the axiomatizability of XML keys is still open, and efficient algorithms for deciding their implication still need to be developed. Solutions to these problems have a wide range of applications including consistency validation, XML schema design, data exchange and integration, consistent query answering, XML query optimization and rewriting, and indexing.
In this article, we investigate the axiomatizability and implication problem for XML keys with nonempty sets of simple key paths. In particular, we propose a set of inference rules that is indeed sound and complete for the implication of such XML keys. We demonstrate that this fragment is robust by showing the duality of XML key implication to the reachability problem of fixed nodes in a suitable digraph. This enables us to develop a quadratic-time algorithm for deciding implication, and shows that reasoning about this XML key fragment is practically efficient. Therefore, XML applications can be unlocked effectively since they benefit not only from those XML keys specified explicitly by the data designer but also from those that are specified implicitly.
Player motivations
Authors: Bostan Barbaros 
Published: June 2009

Although player motivation is one of the main concerns of computer gaming, research so far has been able to identify only a limited set of motives, which are not founded on formal theories of human motivation. Assuming that goal-directed behavior is triggered by the interaction between personal and environmental factors, this article aims to analyze a broader range of gaming motivations derived from basic human needs. The psychological needs investigated in this study are based on the psychogenic needs divided into six categories: materialism, power, affiliation, achievement, information, and sensual needs, defined by Murray [1938] in his extensive research. Since the present work defines motivation as a product of continuous interactions between players and the virtual world, each individual psychological need is briefly described in terms of the actions it provokes. In this context, this article is not concerned with why people play computer games but how they are motivated in the game.
Detailed analysis of the conceptual components of player motivation focuses on matching each psychological need to common gaming situations in computer role-playing games (RPGs). Since this game genre provides interactive virtual environments capable of offering experiences analogous to real life, it is highly relevant to motivational studies. The relationship between motivational factors and gaming situations is discussed with examples from a recently released RPG, which takes place in a fantasy world full of social issues and conflicts, where players usually find themselves in situations that require a choice between the lesser of two evils. It is expected that the variables defined in this study should facilitate the design of computer games that satisfy a broader range of player motivations by providing ways to investigate the relationship between psychological needs and the gaming environment, while bearing in mind the basic components of goal-directed behavior.
Enhancing the educational value of video games
Authors: Bellotti F. , Berta R. , Gloria A. De , Primavera L. 
Published: June 2009

Lowering the barrier between education and real entertainment is an important challenge in order to better exploit the potential of computers and reach a demographic that is traditionally averse to learning. To this end, it is important to investigate how to exploit the appeal of video games (VGs) to also favor and induce learning via playing video games. Achieving this goal is not only a matter of content, since simply “superimposed” educational content risks being perceived as boring. Hence we believe that the game should feature mechanisms for acquiring knowledge and skill that are smoothly embedded in a meaningful, homogeneous, and compelling whole.
Thus, there is a need to compartmentalize components of a game engine so that it becomes easy and efficient to integrate the graphics/interface—which has already been done very well by state-of-the-art successful video games and the educational aspect which is typically poor in those same games. Hence we have defined a general set of mechanisms and modules that can be inserted in state-of-the-art VG environments and are aimed at promoting various kinds of knowledge and procedural skill acquisition.

In order to investigate and validate this concept, we have built an educational game,
SeaGame
, using a state-of-the-art commercial game development approach, and enriched the environment with instances of developed educational modules.

Analyzing user test results, we conclude that
SeaGame
is perceived quite similarly to commercial VGs, which suggests that the proposed mechanisms do not compromise the overall enjoyability of the game, which is key to attracting a wide demographic that is not currently involved in educational activities during their leisure time.

The results of this research can be generalized, since the standards of commercial games and the proposed educational enhancements can be instantiated in a variety of educational contexts and applied to different types of content.
Fixed Point Theorems for Contractive Mappings in Complete "Equation missing" -Metric Spaces
Authors: Mustafa Zead , Sims Brailey 
Published: June 2009

AbstractWe prove some fixed point results for mappings satisfying various contractive conditions on Complete "Equation missing"-metric Spaces. Also the Uniqueness of such fixed point are proved, as well as we showed these mappings are "Equation missing"-continuous on such fixed points.
Revising social work's international policy statement on health
Authors: Bywaters Paul , Napier Lindsey 
Published: June 2009

English This article presents the new IFSW policy statement on health. In addition to describing the consultation process undertaken, it identifies the core content and background analysis informing it. Issues raised include the relationship between local practices of social work and processes of globalization. Implications for future social work policy development are discussed. French Cet article présente la nouvelle déclaration de politique de santé de la FITS. En plus de décrire le processus de consultation entrepris, il identifie le coeur de son contenu et les analyses de fond qui la renseignent. Les questions posées incluent la relation entre les pratiques locales de travail social et les processus de mondialisation. Les implications pour le développement de la politique de travail social future sont discutées. Spanish Este artículo presenta el nuevo manifiesto de la Federación Internacional de Trabajo Social (IFSW) sobre la salud. Además de describir el proceso de consulta llevado a cabo, identifica el contenido básico y el análisis que lo soporta. Las cuestiones que emergen incluyen la relación entre las prácticas locales de trabajo social y los procesos de globalización. Se examinan las implicaciones para el futuro de la política de desarrollo del trabajo social.
Embodying social class
Authors: Rose Stephen M. , Hatzenbuehler Stephanie 
Published: June 2009

English Poverty, income inequality and the inequitable distribution of health invariably co-occur. The strength of the relationship between wealth and health holds even in countries with universal health care. A systematic literature review describes pathways from inequality of wealth to embodied diseases. The significance for social policy and social work practice is developed. French La pauvreté, l’inégalité de revenus et la distribution inégalitaire de la santé se co-produisent invariablement. Le pouvoir de la relation entre richesse et santé s’exerce même dans des pays pourvus d’une couverture santé universelle. Une revue systématique de la littérature décrit les chemins de l’inégalité de la répartition des richesses dans la prise en charge des maladies. La signification pour la politique sociale et la pratique du travail social sera développée. Spanish Hay una concurrencia invariable entre la pobreza, desigualdad de ingresos, y la distribución desigual de la salud. El fuerte vínculo entre riqueza y salud se mantiene incluso en países donde el cuidado de la salud es universal. Una revisión sistemática de la literatura indica las conexiones entre la desigualdad de riqueza y las enfermedades corporales. Se desarrolla lo significativo de la política social y el trabajo social.
Vulnerability
Authors: Fawcett Barbara 
Published: June 2009

English Vulnerability is a policy and practice concept which is often ascribed a fixed meaning with universal connotations. In this article, different conceptualizations of vulnerability are examined. It is argued that this exploration militates against the erosion of self-determination and autonomy and revitalizes working relationships between service users and professionals. French Vulnérabilité est un concept de politique et de pratique auquel est souvent attribuée une signification fixe aux connotations universelles. Dans cet article, les conceptualisations différentes de la vulnérabilité sont examinées. Il y est discuté que cette exploration milite contre l’érosion de l’autodétermination et de l’autonomie et revitalise des rapports de travail entre les usagers des services et les professionnels. Spanish La vulnerabilidad es un concepto de política y práctica social al que se adscribe un significado fijo, con connotaciones universales. Se examinan diferentes conceptualizaciones de vulnerabilidad. Se arguye que este examen milita en contra de la erosión de la autodeterminación y la autonomía, y revitaliza las relaciones de trabajo entre los usuarios de servicios y los profesionales.
Food security and women's health
Authors: Phillips Ruth 
Published: June 2009

English Food security is increasingly affected by global economic and environmental phenomena. Food price increases and food scarcity cause social and political instability, and can escalate to humanitarian crises. As women are particularly likely to be affected by threats to food security, this paper argues for feminist analyses in social work responses and research. French La sécurité alimentaire est de plus en plus affectée par l’économie mondiale et par les phénomènes environnementaux. Les prix des aliments augmentent et la raréfaction de la nourriture est cause d’instabilité sociale et politique, et peut dégénérer en crises humanitaires. Dans la mesure où les femmes sont susceptibles d’être particulièrement affectées par les menaces sur la sécurité alimentaire, cet article argumente en faveur des analyses féministes dans la recherche et les réponses apportées par le travail social. Spanish Los fenómenos del medioambiente y la globalización afectan cada vez más a la seguridad alimenticia. El precio de los alimentos y su escasez causan inestabilidad social y política que pueden abocar a crisis humanitarias. Ya que la seguridad alimenticia tiende a afectar a las mujeres de una forma particular, este artículo arguye a favor de un análisis feminista por parte del trabajo social y la investigación.
Inequalities in health and community-oriented social work
Authors: Backwith Dave , Mantle Greg 
Published: June 2009

English This article argues that, in tackling health inequalities, lessons can be learned from the community-oriented social work which has helped Cuba maintain population health comparable with much wealthier countries, in contrast to the UK where efforts to reduce the health gap between rich and poor have enjoyed limited success. French Cet article soutient que, lorsqu’on aborde les inégalités de santé, des leçons peuvent être tirées du travail social communautaire qui a aidé Cuba à maintenir la santé de sa population à un niveau comparable à celui de pays beaucoup plus riches, par contraste avec le Royaume-Uni où les efforts pour réduire le fossé dans l’accès aux soins entre les riches et les pauvres ont rencontré un succès limité. Spanish Se arguye que, en la lucha contra desigualdades en la salud, se puede aprender de la experiencia del trabajo social comunitario en Cuba. Este trabajo ayudó a que Cuba mantuviera un nivel de salud comparable a la de países mucho más ricos. Todo ello contrasta con el limitado éxito de los esfuerzos en el Reino Unido por reducir distancias en cuanto a salud entre ricos y pobres.
Propofol requirement titrated to bispectral index: a comparison between hypothermic and normothermic cardiopulmonary bypass
Authors: Mathew PJ , Puri GD , Dhaliwal RS 
Published: June 2009

Though propofol requirement is expected to decrease during cardiopulmonary bypass (CPB), a few studies have failed to demonstrate this. The factors affecting pharmacokinetics of propofol and, therefore, the requirement, are different during hypothermic and normothermic CPB. We evaluated and compared the requirement of propofol during hypothermic and normothermic CPB. Fifty adult patients scheduled for elective cardiac surgery on CPB were recruited and randomly allocated into hypothermic CPB (28–300 C) (Group H) and normothermic CPB (35–370 C) (Group N) groups. Patients were induced and maintained with propofol titrated to maintain a target bispectral index (BIS) of 50 ± 10. Propofol requirement (mean ± SD) was similar in normothermic and hypothermic groups, both before CPB (4.9 ± 1.5 mg.kg−1hr−1 in Group N, 4.6 ± 1.5 mg.kg−1hr−1 in Group H) and after cessation of bypass (p > 0.05) (4.6 ± 1.8 mg.kg−1hr−1 in Group N and 4.3 ± 1.7 mg.kg−1hr−1 in Group H). CPB significantly reduced (p < 0.001) propofol requirements in both arms of the study (Group N: 2.9 ± 1.4 mg.kg−1hr−1and Group H: 1.3 ± 0.7 mg.kg−1hr−1). This reduction was more pronounced in the hypothermic group (p < 0.001). The BIS (median ± inter quartile range) remained constant during normothermic CPB (50 ± 8.8), but declined significantly during hypothermic CPB (41 ± 5.6) despite decreased usage of propofol during hypothermia. No patient had recall of intra-operative events. CPB decreases the magnitude of propofol requirements and the effect of hypothermic CPB is significantly more than that of normothermic CPB.
Beneficial effects of modern perfusion concepts in aortic valve and aortic root surgery
Authors: Kutschka I , Skorpil J , El Essawi A , Hajek T , Harringer W 
Published: June 2009

Minimized perfusion circuits (MPC) were found to reduce side effects of standard extracorporeal circulation (ECC). We evaluated the safety and efficacy of the ROCsafe™ MPC for aortic valve and aortic root surgery. One hundred and seventy patients were randomized for surgery using either MPC [n = 85, 30 female/55 male, mean age: 69.8 ± 11.8 years; aortic valve replacement (AVR): n = 40; AVR + coronary artery bypass graft (CABG): n = 31; David operation: n = 3; aortic root replacement (ARR): n = 11] or ECC [n = 85, 29 female/56 male, mean age: 67.7 ± 9.5 years; AVR: n = 39; AVR+CABG: n = 35, David operation: n = 2; ARR: n = 9]. Neurological status, length of ICU stay, C-reactive protein (CRP), blood count, transfusion requirements and bleeding volume were analyzed. The MPC system provided ultrasound-controlled de-airing. A small roller pump and a flexible reservoir were used for left ventricular venting. As a control, we used a standard ECC with cardiotomy suction and hard-shell reservoir. Cross-clamp time (MPC: 76.5 ± 29.5; ECC: 79.0 ± 34.0 min) and bypass time (MPC: 103.0 ± 37.9; ECC: 106.9 ± 44.9 min) were comparable between groups. Transfusion requirements (red blood cells: MPC: 1.5 ± 1.5 vs. ECC: 2.2 ± 2.1 units [p = 0.05], frozen plasma: MPC: 1.2 ± 1.8 vs. ECC: 1.9 ± 2.4 units [p = 0.03]), postoperative bleeding (MPC: 521 ± 283 vs. ECC: 615 ± 326 ml/24 h, p = 0.09) were lower using MPC. ICU stay was shorter with MPC (1.6 ± 1.6 days) compared to ECC (2.4 ± 2.8 days, p = 0.001). One stroke occurred in each group. The ROCsafe™ MPC provides safe circulatory support for a wide range of aortic valve surgeries. Transfusion requirements, postoperative bleeding and length of ICU stay were markedly reduced compared to standard extracorporeal perfusion.
Clinical experience with a novel endotoxin adsorbtion device in patients undergoing cardiac surgery
Authors: Blomquist S , Gustafsson V , Manolopoulos T , Pierre L 
Published: June 2009

Endotoxaemia is thought to occur in cardiac surgery using extracorporeal circulation (ECC) and a positive correlation has been proposed between the magnitude of endotoxaemia and risk for postoperative complications. We studied the effects of a new endotoxin adsorber device (Alteco® LPS adsorber) in patients undergoing cardiac surgery with ECC, with special reference to safety and ease of use. Fifteen patients undergoing coronary artery bypass and/or valvular surgery were studied. In 9 patients, the LPS Adsorber was included in the bypass circuit between the arterial filter and the venous reservoir. Flow through the adsorber was started when the aorta was clamped and stopped at the end of perfusion. Flow rate was kept at 150 ml/min. Six patients served as controls with no adsorber in the circuit. Samples were taken for analysis of endotoxin, TNFα, IL-1ß and IL-6 as well as complement factors C3, C4 and C1q. Whole blood coagulation status was evaluated using thromboelastograpy (TEG) and platelet count. No adverse events were encountered when the adsorber was used in the circuit. Blood flow through the device was easily monitored and kept at the desired level. Platelet count decreased in both groups during surgery. TEG data revealed a decrease in whole blood clot strength in the control group while it was preserved in the adsorber group. Endotoxin was detected in only 2 patients and IL-1ß in 4 patients. IL-6 decreased in both groups whereas no change in TNF concentrations was found. C3 fell in both groups, but no changes wer found in C4 and C1q. The Alteco® LPS adsorber can be used safely and is easy to handle in the bypass circuit. No complications related to the use of the adsorber were noted. The intended effects of the adsorber, i.e. removal of endotoxin from the blood stream could not be evaluated in this study, presumably due to the small number of patients and the relatively short perfusion times.
A Soccer-Specific Balance Training Program for Hamstring Muscle and Patellar and Achilles Tendon Injuries
Authors: Kraemer Robert , Knobloch Karsten 
Published: June 2009

Background A soccer-specific balance training has been shown to decrease injury incidence of the anterior cruciate ligament and ankle sprains in randomized controlled trials. However, hamstring injuries and tendinopathy remain significant issues in soccer. Hypothesis Proprioceptive training can reduce the incidence of hamstring muscle injuries and tendinopathy in elite soccer. There is a dose-effect relationship between balance training duration and injury incidence. Study Design Cohort study; Level of evidence, 3. Methods Twenty-four elite female soccer players (body mass index, 21.7 ± 1.2; age, 21 ± 4 years) of a German premier league soccer team were prospectively included. Starting in January 2004, an additional soccer-specific proprioceptive multistation training was initiated over 3 years. Injury data/1000 hours of exposure with documentation of all occurred injuries, detailed training, and match exposure data as well as time loss data were 100% complete. Results At the end of the 3-year proprioceptive balance training intervention, noncontact hamstring injury rates were reduced from 22.4 to 8.2/1000 hours (P = .021), patellar tendinopathy from 3.0 to 1.0/1000 hours (P = .022), and Achilles tendinopathy from 1.5 to 0.0/1000 hours (P = .035). There was no effect of balance training on contact injuries. Mean time loss of all assessed injuries significantly decreased from 14.4 days during the control period to 1.5 days during intervention periods (P = .003). The more minutes of balance training performed, the lower the rate of overall injuries (r = −0.185, P = .001), hamstring injuries (r = −0.267, P = .003), patellar tendinopathy (r = −0.398, P = .02), and gastrocnemius strains (r = −0.342, P = .002). Conclusion Soccer-specific balance training (protective balancing) can reduce noncontact hamstring injuries and patellar and Achilles tendinopathy. A dose-effect relationship between duration of balance training and injury incidence is evident. A proprioceptive training program reduced the rehabilitation time in noncontact injuries, which warrants further investigation.