The pseudogap: friend or foe of high Tc?

Although nineteen years have passed since the discovery of high temperature superconductivity, there is still no consensus on its physical origin. This is in large part because of a lack of understanding of the state of matter out of which the superconductivity arises. In optimally and underdoped materials, this state exhibits a pseudogap at temperatures large compared to the superconducting transition temperature. Although discovered only three years after the pioneering work of Bednorz and Muller, the physical origin of this pseudogap behavior and whether it constitutes a distinct phase of matter is still shrouded in mystery. In the summer of 2004, a band of physicists gathered for five weeks at the Aspen Center for Physics to discuss the pseudogap. In this perspective, we would like to summarize some of the results presented there and discuss its importance in the context of strongly correlated electron systems.Comment: expanded version, 20 pages, 11 figures, to be published, Advances in Physic

Anxiety and self-esteem as mediators of the relation between family communication and indecisiveness in adolescence

Abstract In this study, we explored the unique and common contributions of anxiety, self-esteem, and family communication on indecisiveness among adolescents. Three hundred and fifty pupils from 13 to 16 years of age completed selfreport measures on indecisiveness, quality of family communication, trait anxiety, and self-esteem. The findings in this study showed that students\u2019 indecisiveness is predicted by family communication mediated by anxiety and self-esteem. These results have important implications for practice as it stresses the importance of anxiety and self-esteem. Nevertheless, the counselors could also focus on enhancing relationship-building skills by introducing the adolescents\u2019 career formation as an adolescent\u2013parent joint project.L\u2019anxie\ub4te\ub4 et l\u2019estime de soi comme me\ub4diateurs de la relation entre communication au sein de la famille et indecision chronique a` l\u2019adolescence. Dans cette e\ub4tude, nous avons explore\ub4 les contributions uniques et communes de l\u2019anxiete\ub4, de l\u2019estime de soi et de la communication au sein de la famille sur l\u2019indecision chronique aupres d\u2019adolescents. Trois cent cinquante e\ub4le`ves a\u2c6ge\ub4s de 13 a` 16 ans ont rempli des mesures d\u2019auto-e\ub4valuation de l\u2019inde\ub4cision chronique, de la qualite\ub4 de la communication familiale, de l\u2019anxie\ub4te\ub4-trait et de l\u2019estime de soi. Les re\ub4sultats de cette e\ub4tude ont montre\ub4 que l\u2019inde\ub4cision des e\ub4tudiants est explique\ub4e par la communication au sein de la famille et que ce lien est me\ub4diatise\ub4 par l\u2019anxie\ub4te\ub4 et l\u2019estime de soi. Ces re\ub4sultats ont des implications importantes pour la pratique car ils soulignent l\u2019importance de l\u2019anxie\ub4te\ub4 et l\u2019estime de soi. Ne\ub4anmoins, les conseillers pourraient e\ub4galement se concentrer sur l\u2019ame\ub4lioration des compe\ub4tences de construction relationnelle en introduisant la formation professionnelle des adolescents comme un projet conjoint adolescent-parent.Resumen. Ansiedad y Autoestima como Mediadores de la Relacio\ub4n entre Comunicacio\ub4n Familiar e Indecisio\ub4n en la Adolescencia. En este estudio, exploramos las contribuciones u\ub4nicas y comunes de la ansiedad, la autoestima y la comunicacio\ub4n de familia en la indecisio\ub4n de los adolescentes. Tres y cientos cincuenta alumnos entre los 13 y 16 an\u2dcos completaron auto-evaluaciones sobre la indecisio\ub4n, la calidad de comunicacio\ub4n familiar, los rasgos de ansiedad y la autoestima. Los resultados en este estudio muestran que la indecisio\ub4n en los estudiantes es prevista por la comunicacio\ub4n familiar mediada por la ansiedad y la autoestima. Estos resultados tiene importantes implicaciones para la practica ya que destacan la importancia de la ansiedad y la autoestima. Sin embargo, los consejeros podr\u131\ub4an tambie\ub4n focalizarse en el aumento de sus habilidades para construir relaciones mediante la introduccio\ub4n de la formacio\ub4n profesional para adolescentes como un proyecto conjunto del adolescente-padre.Angst und Selbstwertgefu\ua8 hl als Mediatoren der Beziehung zwischen Kommunikation in der Familie und Unentschlossenheit in der Adoleszenz. In dieser Studie untersuchten wir die spezifischen und gemeinsamen Beitra\ua8ge von Angst, Selbstwertgefu\ua8hl und Kommunikation in der Familie auf Unentschlossenheit unter Jugendlichen. Dreihundertfu\ua8nfzig Schu\ua8ler, zwischen 13 bis 16 Jahre alt, fu\ua8llten Skalen zur Unentschlossenheit, Qualita\ua8t der Kommunikation in der Familie, A\ua8 ngstlichkeit und Selbstwertgefu\ua8hl aus. Die Ergebnisse dieser Studie zeigten, dass Unentschlossenheit der Schu\ua8ler von Kommunikation in der Familie vorhergesagt wird, vermittelt durch Angst und Selbstwertgefu\ua8 hl. Diese Ergebnisse haben wichtige Implikationen fu\ua8r die Praxis, da sie die Bedeutung von Angst und Selbstwertgefu\ua8hl hervorheben. Dennoch ko\ua8nnten sich die Beratungspersonen durch die Einfu\ua8hrung der beruflichen Bildung der Jugendlichen als ein gemeinsames Projekt von Jugendliche-Elternteil auch auf die Verbesserung der Fa\ua8higkeiten zum Aufbau von Beziehungen konzentrieren

Performance of the CMS Cathode Strip Chambers with Cosmic Rays

The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns

The effects of buoyancy on sonoluminescing bubbles

Sonoluminescence from a single bubble was studied under microgravity and hypergravity environments to determine how buoyancy affects the light emission. The long-term objective of these experiments is to determine if buoyancy-related instabilities play a role in limiting the parameter space of single-bubble sonoluminescence. Understanding the parameter space limitations may ultimately lead to novel approaches for enhancing the extreme conditions within the bubble. Our results reveal several buoyancy-related effects, which should be further investigated in an extended microgravity environment

Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO

Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO

Multigrid algorithms for hp-version interior penalty discontinuous Galerkin methods on polygonal and polyhedral meshes

In this paper we analyze the convergence properties of two-level and W-cycle multigrid solvers for the numerical solution of the linear system of equations arising from hp-version symmetric interior penalty discontinuous Galerkin discretizations of second-order elliptic partial differential equations on polygonal/polyhedral meshes. We prove that the two-level method converges uniformly with respect to the granularity of the grid and the polynomial approximation degree p, provided that the number of smoothing steps, which depends on p, is chosen sufficiently large. An analogous result is obtained for the W-cycle multigrid algorithm, which is proved to be uniformly convergent with respect to the mesh size, the polynomial approximation degree, and the number of levels, provided the latter remains bounded and the number of smoothing steps is chosen sufficiently large. Numerical experiments are presented which underpin the theoretical predictions; moreover, the proposed multilevel solvers are shown to be convergent in practice, even when some of the theoretical assumptions are not fully satisfied

A nationwide study on reproductive function, ovarian reserve, and risk of premature menopause in female survivors of childhood cancer: design and methodological challenges

<p>Abstract</p> <p>Background</p> <p>Advances in childhood cancer treatment over the past decades have significantly improved survival, resulting in a rapidly growing group of survivors. However, both chemo- and radiotherapy may adversely affect reproductive function. This paper describes the design and encountered methodological challenges of a nationwide study in the Netherlands investigating the effects of treatment on reproductive function, ovarian reserve, premature menopause and pregnancy outcomes in female childhood cancer survivors (CCS), the DCOG LATER-VEVO study.</p> <p>Methods</p> <p>The study is a retrospective cohort study consisting of two parts: a questionnaire assessing medical, menstrual, and obstetric history, and a clinical assessment evaluating ovarian and uterine function by hormonal analyses and transvaginal ultrasound measurements. The eligible study population consists of adult female 5-year survivors of childhood cancer treated in the Netherlands, whereas the control group consists of age-matched sisters of the participating CCS. To date, study invitations have been sent to 1611 CCS and 429 sister controls, of which 1215 (75%) and 333 (78%) have responded so far. Of these responders, the majority consented to participate in both parts of the study (53% vs. 65% for CCS and sister controls respectively). Several challenges were encountered involving the study population: dealing with bias due to the differences in characteristics of several types of (non-) participants and finding an adequately sized and well-matched control group. Moreover, the challenges related to the data collection process included: differences in response rates between web-based and paper-based questionnaires, validity of self-reported outcomes, interpretation of clinical measurements of women using hormonal contraceptives, and inter- and intra-observer variation of the ultrasound measurements.</p> <p>Discussion</p> <p>The DCOG LATER-VEVO study will provide valuable information about the reproductive potential of paediatric cancer patients as well as long-term survivors of childhood cancer. Other investigators planning to conduct large cohort studies on late effects may encounter similar challenges as those encountered during this study. The solutions to these challenges described in this paper may be useful to these investigators.</p> <p>Trial registration</p> <p>NTR2922; <url>http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=2922</url></p

Sleep-Disordered Breathing in Alcoholics

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66229/1/j.1530-0277.1999.tb04034.x.pd