bluuebunny/crossref_metadata_2025 huggingface dataset:
How Should We Assess the Fit of Rasch-Type Models? Approximating the Power of Goodness-of-Fit Statistics in Categorical Data Analysis
Authors: Maydeu-Olivares Alberto , Montaño Rosa
Published: October 2012

We investigate the performance of three statistics, R1, R2 (Glas in Psychometrika 53:525–546, 1988), and M2 (Maydeu-Olivares & Joe in J. Am. Stat. Assoc. 100:1009–1020, 2005, Psychometrika 71:713–732, 2006) to assess the overall fit of a one-parameter logistic model (1PL) estimated by (marginal) maximum likelihood (ML). R1 and R2 were specifically designed to target specific assumptions of Rasch models, whereas M2 is a general purpose test statistic. We report asymptotic power rates under some interesting violations of model assumptions (different item discrimination, presence of guessing, and multidimensionality) as well as empirical rejection rates for correctly specified models and some misspecified models. All three statistics were found to be more powerful than Pearson’s X2 against two- and three-parameter logistic alternatives (2PL and 3PL), and against multidimensional 1PL models. The results suggest that there is no clear advantage in using goodness-of-fit statistics specifically designed for Rasch-type models to test these models when marginal ML estimation is used.
Vitamin C Enhances Vitamin E Status and Reduces Oxidative Stress Indicators in Sea Bass Larvae Fed High DHA Microdiets
Authors: Betancor Mónica B. , Caballero Mª. José , Terova Genciana , Corà Samuela , Saleh Reda , Benítez‐Santana Tibiábin , Bell J. Gordon , Hernández‐Cruz Carmen María , Izquierdo Marisol
Published: October 2012

Docosahexaenoic acid (DHA) is an essential fatty acid necessary for many biochemical, cellular and physiological functions in fish. However, high dietary levels of DHA increase free radical injury in sea bass (Dicentrarchus labrax) larvae muscle, even when vitamin E (α‐tocopherol, α‐TOH) is increased. Therefore, the inclusion of other nutrients with complementary antioxidant functions, such as vitamin C (ascorbic acid, vitC), could further contribute to prevent these lesions. The objective of the present study was to determine the effect of vitC inclusion (3,600 mg/kg) in high DHA (5 % DW) and α‐TOH (3,000 mg/kg) microdiets (diets 5/3,000 and 5/3,000 + vitC) in comparison to a control diet (1 % DHA DW and 1,500 mg/kg of α‐TOH; diet 1/1,500) on sea bass larvae growth, survival, whole body biochemical composition and thiobarbituric acid reactive substances (TBARS) content, muscle morphology, skeletal deformities and antioxidant enzymes, insulin‐like growth factors (IGFs) and myosin expression (MyHC). Larvae fed diet 1/1,500 showed the best performance in terms of total length, incidence of muscular lesions and ossification degree. IGFs gene expression was elevated in 5/3,000 diet larvae, suggesting an increased muscle mitogenesis that was confirmed by the increase in the mRNA copies of MyHC. vitC effectively controlled oxidative damages in muscle, increased α‐TOH larval contents and reduced TBARS content and the occurrence of skull deformities. The results of the present study showed the antioxidant synergism between vitamins E and C when high contents of DHA are included in sea bass larvae diets.
Intérêt de la ponction épididymaire et de la biopsie testiculaire systématique dans la prise en charge de l’azoospermie obstructive
Authors: Salama S. , Boitrelle F. , Albert M. , Hammoud I. , Huchon C. , Wainer R. , Selva J. , Bailly M.
Published: October 2012

Introduction

Dans l’azoospermie obstructive (AO), les taux d’extraction chirurgicale de spermatozoïdes sont élevés. Cependant, en ce qui concerne les issues des ICSI (Intra cytoplasmic Sperm Injection) chirurgicales, les données de la littérature divergent. Quels sont, dans notre équipe, les taux d’extraction de spermatozoïdes après aspiration épidydimaire (MESA) et après extraction testiculaire (TESE) dans l’AO ? Les taux de grossesses, les taux de fausses couches spontanées et d’accouchements diffèrent-ils en fonction de l’origine du sperme ?

Matériels et méthodes

L’étude a rétrospectivement inclus 48 couples dont l’homme présente une azoospermie obstructive pure et ayant bénéficié d’un prélèvement chirurgical de spermatozoïdes associant systématiquement MESA et TESE. Les ICSI ont été réalisées de manière asynchrone. À chaque fois que cela était possible, la première ICSI a été réalisée avec des spermatozoïdes épididymaires.

Résultats

Pour les 48 couples, 99 ICSI ont été réalisées. Quinze couples ont réalisé 24 ICSI-TESE car l’aspiration épididymaire était négative. Onze couples ont réalisé 20 ICSI-TESE car la qualité du prélèvement épididymaire n’était pas satisfaisante (vitalité spermatique réduite le plus souvent). Vingt-deux couples ont réalisé 22 ICSI-MESA en première intention puis en cas d’échec, 11 couples ont réalisé 12 ICSI-MESA et dix couples ont réalisé 20 ICSI-TESE. Alors que les nombres d’ovocytes injectés (7,1±4,1 vs 6,9 ±3,6 P: 0,8) et d’embryons obtenus (4,5±3,0 vs 4,7±2,7; P: 0,7) ne sont pas significativement différents dans les deux groupes d’ICSI, les nombres d’embryons de top qualité (2,4±1,9 vs 3,6±2,0 P: 0,005) et d’embryons congelés (0,9±1,8 vs 1,7±1,9 P: 0,04) sont significativement supérieurs dans le groupe TESE. Le nombre de grossesse par ponction est supérieur dans le groupe TESE (58,5 % vs 26,5 %, P: 0,002).

Conclusion

L’approche de notre centre a la particularité d’associer systématiquement un prélèvement testiculaire au prélèvement épididymaire chez tout homme présentant une azoospermie obstructive alors que la plupart des autres études rapportées se limitent à l’exploration épididymaire si cette dernière est positive lors de l’examen extemporané. Alors que classiquement, on rapporte 100% de positivité lors du prélèvement épididymaire chez l’homme atteint d’une azoospermie obstructive, dans notre étude, plus de la moitié des explorations épididymaires s’est avérée inexploitable. La qualité embryonnaire et les taux de grossesses sont meilleurs avec des spermatozoïdes testiculaires. L’association de ces 2 sites de prélèvement (MESA et TESE) peut être complémentaire et utile pour le couple et l’issue de sa prise en charge en AMP sans pour autant entraîner un sur-risque pour l’homme dans les suites de la chirurgie.
Iodine deficiency among Belgian pregnant women not fully corrected by iodine-containing multivitamins: a national cross-sectional survey
Authors: Vandevijvere Stefanie , Amsalkhir Sihame , Mourri Ahmed Bensouda , Van Oyen Herman , Moreno-Reyes Rodrigo
Published: October 2012

Low iodine intake during pregnancy may cause thyroid dysfunction in pregnant women and their newborn. In the present study, iodine status among a nation-wide representative sample of Belgian pregnant women in the first and third trimester of pregnancy was determined, and determinants of iodine status were assessed 1 year after the introduction of bread fortified with iodised salt. The women were selected according to a multistage proportionate-to-size sampling design. Urine samples were collected and a general questionnaire was completed face to face with the study nurse. The median urinary iodine concentration (UIC) among pregnant women (n1311) was 124·1 μg/l and 122·6 μg/g creatinine when corrected for urinary creatinine. The median UIC in the first trimester (118·3 μg/l) was significantly lower than that in the third trimester (131·0 μg/l) but significantly higher than among non-pregnant women (84·8 μg/l). Iodine-containing supplement intake was reported by 60·8 % of the women and 57·4 % of the women took this supplement daily. The risk of iodine deficiency was significantly higher in younger women, in women not taking iodine-containing supplements, with low consumption of milk and dairy drinks and during autumn. Women with a higher BMI had a higher risk of iodine deficiency but the risk was lower in women who reported alcohol consumption. The median UIC during pregnancy indicates iodine deficiency in Belgium and some women are at a higher risk of deficiency. The current low iodine intake in women of childbearing age precludes the correction of iodine deficiency in pregnant women supplemented with multivitamins containing 150 μg iodine as recommended.
Growth and reproductive cycle of Hypermastus tokunagai (Caenogastropoda: Eulimidae), an ectoparasite of the sand dollar Scaphechinus mirabilis (Clypeasteroida: Scutellidae) in the Seto Inland Sea, Japan
Authors: Matsuda Haruna , Hamano Tatsuo , Nagasawa Kazuya
Published: October 2012

Hypermastus tokunagai is a eulimid gastropod infecting the sand dollar Scaphechinus mirabilis. The eulimid is easily detached from the host and thus regarded as a temporary parasite. In this study, the growth and reproductive cycle of H. tokunagai were investigated using specimens collected from S. mirabilis in the western Seto Inland Sea, Japan. Newly recruited individuals of H. tokunagai appeared in early autumn and grew rapidly, while growth was retarded from mid-autumn to winter months. A second rapid growth occurred the following summer. Based on the growth pattern, the life span of H. tokunagai was estimated to be more than 20 months. This longer life span compared to other eulimids could be due to the accessibility and population stability of its host S. mirabilis. Maturation of H. tokunagai occurred within a short period in the summer, and was synchronized with the second growth phase. Hypermastus tokunagai showed size dimorphism between sexes and an investigation on change in shell shape with growth revealed that this characteristic can be attributed to the female's acquisition of a larger shell within a short time during its maturation period.
Identification and management of prisoners with severe psychiatric illness by specialist mental health services
Authors: Senior J. , Birmingham L. , Harty M. A. , Hassan L. , Hayes A. J. , Kendall K. , King C. , Lathlean J. , Lowthian C. , Mills A. , Webb R. , Thornicroft G. , Shaw J.
Published: October 2012

Background

The prevalence of mental disorders among prisoners is considerably higher than in the general population. This is an important public health issue as the vast majority of prisoners stay in custody for less than 9 months and, when not in prison, offenders' lifestyles are frequently chaotic, characterized by social exclusion, instability and unemployment. Multi-disciplinary mental health inreach services were introduced to target care towards prisoners with severe mental illness (SMI) in a similar way to that provided by Community Mental Health Teams outside prison. The aim was to establish the proportion of prisoners with SMI who were assessed and managed by prison mental health inreach services.

Method

A two-phase prevalence survey in six prisons in England measured SMI upon reception into custody. Case-note review established the proportion of those with SMI subsequently assessed and treated by inreach services.

Results

Of 3492 prisoners screened, 23% had SMI. Inreach teams assessed only 25% of these unwell prisoners, and accepted just 13% onto their caseloads.

Conclusions

Inreach teams identified and managed only a small proportion of prisoners with SMI. Prison-based services need to improve screening procedures and develop effective care pathways to ensure access to appropriate services. Improved identification of mental illness is needed in both the community and the Criminal Justice System to better engage with socially transient individuals who have chaotic lifestyles and complex needs.
The Astronomical Interpretation of Catoptrica
Authors: Mota Bernardo Machado
Published: October 2012

Argument

A Catoptrica attributed to Euclid appears in manuscripts amongst treatises dealing with elementary astronomy. Despite this textual background, the treatise has always been read literally as a theory of mirrors, and its astronomical significance has gone unnoticed. However, optics, catoptrics, and astronomy appear strongly intermingled in sources such as, amongst others, Geminus, Theon of Smyrna, Plutarch and Cleomedes. If one compares the optical reasoning put forward in these sources to account for the formation of moonlight with arguments of Catoptrica, one is able to shed new light on several principles and propositions of Catoptrica, some of which had been deemed corrupt, meaningless, and obscure. Moreover, the present analysis offers a glimpse at the context of a specific stage in the evolution of ancient catoptrics: Whether literally or by analogy, several of its results appear to have been set against a wider astronomical background, which explains the inclusion of Catoptrica in the group of texts loosely defined as “little astronomy.”
Impact of the 7-valent pneumococcal conjugate vaccine on the incidence of childhood pneumonia
Authors: ELEMRAID M. A. , RUSHTON S. P. , SHIRLEY M. D. F. , THOMAS M. F. , SPENCER D. A. , EASTHAM K. M. , HAMPTON F. , GORTON R. , POLLARD K. , GENNERY A. R. , CLARK J. E.
Published: October 2012

In September 2006, the 7-valent pneumococcal conjugate vaccine (PCV7) was added to the UK immunization programme. We aimed to evaluate the impact of PCV7 on the incidence of all-cause community-acquired pneumonia (CAP) in children. A prospective survey was undertaken in 2008–2009 at 11 hospitals in North East England of children aged 0–16 years with radiologically confirmed pneumonia. Data were compared to those from a similar survey undertaken in the same hospitals in 2001–2002. A total of 542 children were enrolled, of which 74% were aged <5 years. PCV7 uptake was 90·7%. The incidence of pneumonia was 11·8/10 000 [95% confidence interval (CI) 10·9–12·9], and the hospitalization rate was 9·9/10 000 (95% CI 9·0–10·9). Compared to 2001, there was a 19% (95% CI 8–29) reduction in the rate of CAP in those aged <5 years, and in those <2 years a 33·1% (95% CI 20–45) reduction in the incidence of CAP and 38·1% (95% CI 24–50) reduction in hospitalization rates. However, for those unvaccinated aged ⩾5 years, there was no difference in the incidence of CAP and hospitalization rate between both surveys. Since 2001, the overall reduction in incidence was 17·7% (95% CI 8–26) and for hospitalization 18·5% (95% CI 8–28). For the <5 years age group there was a lower incidence of CAP in PCV7-vaccinated children (25·2/10 000, 95% CI 22·6–28·2) than in those that were not vaccinated (37·4/10 000, 95% CI 29·2–47·1). In conclusion, PCV7 has reduced both incidence and rate of hospitalization of pneumonia in children, particularly in the <2 years age group.
Forced relocation between nursing homes: residents' health outcomes and potential moderators
Authors: Holder Jacquetta M , Jolley David
Published: October 2012

That transfer of older people from one institution to another is detrimental to well-being, health and survival has been reported for 50 years. This has led to fear, anger and legal challenges when closures occur. Previous reviews identified accounts of relocation followed by adverse outcomes and others where problems were avoided or benefits claimed. This paper reviews the last twelve years of literature on health outcomes following involuntary relocation between nursing homes. Reports of post-move mortality, physical or psychological health suggest and confirm that relocation without preparation carries higher risk of poor outcomes than moves that are orderly and include preparation. The literature on the care home closure process, admissions and individual transfers offers insights into practices that might help minimize adverse outcomes. A number of agencies have produced helpful guidelines. How these are implemented needs to be monitored and linked to in-depth studies of sample closures.
A systematic review of the pharmacological management of aortic root dilation in Marfan syndrome
Authors: Thakur Varsha , Rankin Kathryn N. , Hartling Lisa , Mackie Andrew S.
Published: October 2012

Background

Marfan syndrome causes aortic dilation leading to dissection and death. This systematic review examined the use of beta-blockers, angiotensin-converting enzyme inhibitors, and angiotensin II receptor blockers in the management of aortic dilation in this disease.

Methods

We searched four databases – Medline, EMBASE, Web of Science, and The Cochrane Central Register of Controlled Trials – two conference proceedings, references of retrieved articles, and a web-based trial registry. The primary outcome was mortality. The secondary outcomes were aortic dissection, need for elective surgical repair, change in aortic dilation, and adverse events. Two reviewers selected studies, abstracted data, and assessed study quality. Meta-analyses were not performed because of study heterogeneity.

Results

A total of 18 studies were included – 12 completed and six in progress. Of the completed studies, three before-and-after treatment, one prospective cohort, three retrospective cohorts, and two randomised control trials examined beta-blockers; one randomised and one non-randomised trial examined angiotensin-converting enzyme inhibitors; and one retrospective cohort study examined angiotensin II receptor blockers. Studies in progress are all randomised trials. Mortality was not impacted by drug therapy, although studies were underpowered with respect to this outcome. All drug classes were associated with a decrease in the rate of aortic dilation (angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers >beta-blockers); none had an impact on other secondary outcomes.

Conclusions

On the basis of existing evidence, beta-blockers, angiotensin-converting enzyme inhibitors, and angiotensin II receptor blockers slow the progression of aortic dilation in Marfan syndrome. Angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers may have more effect than beta-blockers; however, more methodologically rigorous studies currently in progress are needed to evaluate the impact of drug therapy on clinical outcomes.
A sibling-controlled, prospective study of outcomes at home and school in children with severe congenital heart disease
Authors: McCusker Christopher G. , Armstrong Mark P. , Mullen Mairead , Doherty Nicola N. , Casey Frank A.
Published: October 2012

Objectives

The objectives of this study were to compare behaviour problems and competencies, at home and school, in 7-year-old children with congenital heart disease with a sibling control group, to examine the prospective determinants of outcome from infancy, and to explore whether any gains were maintained in our sub-group of children who had participated in a previous trial of psychological interventions in infancy.

Methods

A total of 40 children who had undergone surgery to correct or palliate a significant congenital heart defect in infancy were compared (Child Behavior Checklist) with a nearest-age sibling control group (18 participants). Comparisons were made between sub-groups of children and families who had and had not participated in an early intervention trial.

Results

Problems with attention, thought and social problems, and limitations in activity and school competencies, were found in comparison with siblings. Teacher reports were consistent with parents, although problems were of a lower magnitude. Disease, surgical, and neurodevelopmental functioning in infancy were related to competence outcomes but not behaviour problems. The latter were mediated by family and maternal mental health profiles from infancy. Limited, but encouraging, gains were maintained in the sub-group that had participated in the early intervention programme.

Conclusions

The present study is strengthened by its longitudinal design, use of teacher informants, and sibling control group. The patterns of problems and limitations discerned, and differential determinants thereof, have clear implications for interventions. We consider these in the light of our previously reported intervention trial with this sample and current outcomes at the 7-year follow-up.
A common risk classification system for the Actuarial Profession
Authors: Kelliher P. O. J. , Wilmot D. , Vij J. , Klumpes P. J. M.
Published: October 2012

Risk terminology varies from organisation to organisation, and actuaries working in different organisations may use different terms to refer to the same risk, or use the same nomenclature for completely different risks. This paper sets out a classification system developed by the Risk Classification Working Party for the Profession that can be used as a common reference point for discussing risk. Actuaries will not be required to use this system, but it is hoped that common terminology will reduce the possibility of confusion in discussing risks.
Prevalence of elevated mean arterial pressure and how fitness moderates its association with BMI in youth
Authors: Ogunleye Ayodele A , Sandercock Gavin R , Voss Christine , Eisenmann Joey C , Reed Katharine
Published: October 2012

Objective

Cardiorespiratory fitness is known to be cardioprotective and its association with the components of the metabolic syndrome in children is becoming clearer. The aim of the present study was to examine the extent to which cardiorespiratory fitness may offset the weight-related association with mean arterial pressure (MAP) in schoolchildren.

Design

Cross-sectional study.

Settings

Schoolchildren from the East of England, UK.

Subjects

A total of 5983 (48 % females) schoolchildren, 10 to 16 years of age, had height, weight and blood pressure measured by standard procedures and cardiorespiratory fitness assessed by the 20 m shuttle-run test. Participants were classified as fit or unfit using internationally accepted fitness cut-off points; and as normal weight, overweight or obese based on BMI, again using international cut-off points. Age-adjusted ANCOVA was used to determine the main effects and interaction of fitness and BMI on MAP Z-score. Logistic regression models were used to estimate odds ratios of elevated MAP.

Results

Prevalence of elevated MAP in schoolchildren was 14·8 % overall and 35·7 % in those who were obese-unfit. Approximately 21 % of participants were overweight and 5 % obese, while 23 % were classified as unfit. MAP generally increased across BMI categories and was higher in the aerobically unfit participants. Obese-fit males had lower MAP compared with obese-unfit males (P < 0·001); this trend was similar in females (P = 0·05).

Conclusions

Increasing fitness level may have a positive impact on the weight-related elevations of MAP seen in obese and overweight schoolchildren.
Restoring Miranda: gender and the limits of European patriarchy in the early modern Atlantic world
Authors: Amussen Susan D. , Poska Allyson M.
Published: October 2012

Atlantic history has become fashionable as a way of linking the histories of Europe and the Americas. However, much work in Atlantic history does little to challenge the national biases of traditional colonial and imperial history. This article argues that gender provides an important conceptual tool for a trans-imperial and comparative exploration, just as it provided important conceptual structures for all the peoples of the Atlantic world. An examination of the research on two gendered issues – work, and family and sexuality – demonstrates that while Europeans attempted to impose their ideas on the various societies that they encountered in Africa and the Americas, such attempts were rarely successful. Gender not only provides the basis for a trans-imperial analysis of the Atlantic world but also enables us to reorient our scholarly perspective in the Atlantic, highlighting the agency of non-European peoples and exposing the limits of European patriarchy.
Comparing the United States and United Kingdom: contrasts and correspondences
Authors: Klein Rudolf
Published: October 2012

The conventionally antithetical stereotypes of the United Kingdom and United States health care systems needs to be modified in the case of the elderly. Relative to the rest of the population, the over-65s in the United States are more satisfied with their medical care than their UK counterparts. There is also much common ground: shared worries about the quality of elderly care and similar attitudes towards assisted death. Comparison is further complicated by within country variations: comparative studies should take account of the fact that even seemingly polar models may have pools of similarity.
Valuing end-of-life care in the United States: the case of new cancer drugs
Authors: Sorenson Corinna
Published: October 2012

New cancer therapies offer the hope of improved diagnosis to patients with life-threatening disease. Over the past 5–10 years, a number of specialty drugs have entered clinical practice to provide better systemic therapy for advanced cancers that respond to few therapeutic alternatives. To date, however, such advances have been only modestly effective in extending life and come with a high price tag, raising questions about their value for money, patient access and implications for health care costs. This article explores some of the key issues present in valuing end-of-life care in the United States in the case of advanced cancer drugs, from the difficult trade-offs between their limited health benefits and high costs to the technical, political and social challenges in assessing their value and applying such evidence to inform policy and practice. A number of initial steps are discussed that could be pursued to improve the value of advanced cancer care.
End-of-life care for patients with dementia in the United States: institutional realities
Authors: Gusmano Michael
Published: October 2012

Few are satisfied with end-of-life care in the United States. For families and friends of people with dementia, end-of-life care is particularly frustrating. Providing better end-of-life care to people with dementia is urgent because the prevalence of the disease is increasing rapidly. Dementia is currently the seventh leading cause of death in the United States and fifth leading cause of death among people aged 65 years and older. By 2050, there will be around 19 million people with Alzheimer's disease. This article reviews ethical and policy challenges associated with providing end-of-life care for people with dementia in the United States. I explain how disagreements about the meaning of futility lead to poor care for people with dementia. Most people agree that we should not provide care that is futile, but there is little agreement about how futility should be defined. US policies and politics clearly tip the balance in the direction of treatment, even in the face of strong evidence that such care does more harm than good. Although we may never reach a consensus, it is important to address these questions and think about how to develop policies that respect the different values.
The TRIPS Patent Protection Provisions and Their Effects on Transferring Climate Change Technologies to LDCs and Poor Developing Countries: A Critical Appraisal
Authors: ZAMAN Khorsed
Published: October 2012

Despite the existence of almost eighty international agreements and legal instruments, there has not been a marked development in the transfer of climate change technologies to poor and the least developing countries. This article investigates the role of intellectual property rights (IPDs) and scrutinizes the effects of the WTO Agreement on Trade-Related Aspects of Intellectual Property Rights (TRIPS) on the transfer of these technologies. It explores the TRIPS patent protection provisions and examines the associated flexibilities like compulsory licensing and parallel import options in the context of the transfer of climate change technologies. It finally concludes that the TRIPS patent protection rules, including the existing flexibilities, are one of the biggest impediments to the transfer of these technologies to poor and least developed countries. New agreements or promises on the transfer of green technologies would be fruitless if these TRIPS rules are not amended.
The Twin Research Registry at SRI International
Authors: Krasnow Ruth E. , Jack Lisa M. , Lessov-Schlaggar Christina N. , Bergen Andrew W. , Swan Gary E.
Published: October 2012

The Twin Research Registry (TRR) at SRI International is a community-based registry of twins established in 1995 by advertising in local media, mainly on radio stations and in newspapers. As of August 2012, there are 3,120 same- and opposite-sex twins enrolled; 86% are 18 years of age or older (mean age 44.9 years, SD 16.9 years) and 14% less than 18 years of age (mean age 8.9 years, SD 4.5); 67% are female, and 62% are self-reported monozygotic (MZ). More than 1,375 twins have participated in studies over the last 15 years in collaboration with the University of California Medical Center in San Francisco, the University of Texas MD Anderson Cancer Center, and the Stanford University School of Medicine. Each twin completes a registration form with basic demographic information either online at the TRR Web site or during a telephone interview. Contact is maintained with members by means of annual newsletters and birthday cards. The managers of the TRR protect the confidentiality of twin data with established policies; no information is given to other researchers without prior permission from the twins; and all methods and procedures are reviewed by an Institutional Review Board. Phenotypes studied thus far include those related to nicotine metabolism, mutagen sensitivity, pain response before and after administration of an opioid, and a variety of immunological responses to environmental exposures, including second-hand smoke and vaccination for seasonal influenza virus and Varicella zoster virus. Twins in the TRR have participated in studies of complex, clinically relevant phenotypes that would not be feasible to measure in larger samples.
Diagnostische Kompetenz von Englischlehrkräften
Authors: Leucht Michael , Tiffin-Richards Simon , Vock Miriam , Pant Hans Anand , Köller Olaf
Published: October 2012

Der vorliegende Beitrag thematisiert die diagnostische Kompetenz von Englischlehrkräften am Ende der Sekundarstufe I. Die 56 untersuchten Lehrkräfte wurden gebeten, für jeden der von ihnen unterrichteten 1 363 Schülerinnen und Schüler ein Niveau der Fremdsprachverwendung anzugeben, wie sie der Gemeinsame Europäische Referenzrahmen für Sprachen (GER) beschreibt. Den Lehrkrafturteilen wurden per Leistungstest ermittelte GER-Niveaus für das Leseverstehen in der ersten Fremdsprache Englisch gegenübergestellt, ihre Übereinstimmung anhand der Niveau-, Differenzierungs- und Rangkomponente quantifiziert. Jenseits einer Deskription diagnostischer Kompetenz adressiert der vorliegende Beitrag die Überlagerung der GER-Urteile durch die klasseninterne Norm der Notengebung, die über einen Abgleich von Lehrkrafturteilen und Zeugnisnoten im Fach Englisch empirisch geprüft wird. Zudem wird eine mehrebenenanalytische Modellierung diagnostischer Kompetenz vorgestellt. Sie prüft, inwieweit die Höhe der klassischen Rangkomponente sowie einer mehrebenenanalytischen Entsprechung der Niveaukomponente durch die Vertrautheit von Lehrkräften mit dem GER und seiner früheren Nutzung bei der Beurteilung der unterrichteten Schülerinnen und Schüler beeinflusst werden.
Visible and thermal infrared observations of the Martian surface during three Phobos shadow transits
Authors: Piqueux Sylvain , Christensen Philip R.
Published: October 2012

We present visible and thermal infrared observations of the Martian surface acquired during three Phobos transits. Observations show a decrease of up to ∼20% of the reflected solar energy, consistent with the fraction of the Sun disk eclipsed by Phobos, and no measurable surface cooling. Thermal modeling indicates that the top millimeter of the regolith has a thermal inertia larger than 100 J m−2 K−1 s−1/2 regardless of the surface morphology, and is consistent with TES regional thermal inertia values derived from diurnal cycles (e.g. ∼200 J m−2 K−1 s−1/2). The thermophysical properties of the top millimeter of the regolith exclude the presence of widespread thermally‐thick dust layers, are consistent with those of the diurnal skin depths at TES and THEMIS spatial resolutions, are in accordance with high‐resolution images of the surface showing no surface mantling, with General Circulation Model results, thermally derived rock abundance values, albedo, and spectroscopic data.
Temporal evolution and electric potential structure of the auroral acceleration region from multispacecraft measurements
Authors: Forsyth C. , Fazakerley A. N. , Walsh A. P. , Watt C. E. J. , Garza K. J. , Owen C. J. , Constantinescu D. , Dandouras I. , Fornaçon K.‐H. , Lucek E. , Marklund G. T. , Sadeghi S. S. , Khotyaintsev Y. , Masson A. , Doss N.
Published: October 2012

Bright aurorae can be excited by the acceleration of electrons into the atmosphere in violation of ideal magnetohydrodynamics. Modeling studies predict that the accelerating electric potential consists of electric double layers at the boundaries of an acceleration region but observations suggest that particle acceleration occurs throughout this region. Using multispacecraft observations from Cluster, we have examined two upward current regions on 14 December 2009. Our observations show that the potential difference below C4 and C3 changed by up to 1.7 kV between their respective crossings, which were separated by 150 s. The field‐aligned current density observed by C3 was also larger than that observed by C4. The potential drop above C3 and C4 was approximately the same in both crossings. Using a novel technique of quantitively comparing the electron spectra measured by Cluster 1 and 3, which were separated in altitude, we determine when these spacecraft made effectively magnetically conjugate observations, and we use these conjugate observations to determine the instantaneous distribution of the potential drop in the AAR. Our observations show that an average of 15% of the potential drop in the AAR was located between C1 at 6235 km and C3 at 4685 km altitude, with a maximum potential drop between the spacecraft of 500 V, and that the majority of the potential drop was below C3. Assuming a spatial invariance along the length of the upward current region, we discuss these observations in terms of temporal changes and the vertical structure of the electrostatic potential drop and in the context of existing models and previous single‐ and multispacecraft observations.
Dynamic capillary effects in a small‐volume unsaturated porous medium: Implications of sensor response and gas pressure gradients for understanding system dependencies
Authors: Hou Lili , Chen Lixia , Kibbey Tohren C. G.
Published: October 2012

Rate dependencies in system properties observed during nonsteady state unsaturated and multiphase flow are often referred to as dynamic capillary effects. One widely studied dynamic capillary effect is the apparent dependence of measured capillary pressure on the rate of saturation change. While this phenomenon has been observed for over four decades, a clear picture of the source of the phenomenon and its true magnitude remains elusive. Furthermore, reported dependencies on system properties and state variables have been contradictory. The focus of this work was on quantifying the relationship between measured capillary pressure and rate of saturation change using a small volume system with highly characterized fluid‐selective microsensors. Experimental measurements in three systems were used to calculate the dynamic capillary coefficientτas a function of saturation during drainage. Corrections for sensor response and flow‐induced gas pressure gradients were applied to explore how these potential artifacts would impact measuredτvalues. Significant differences inτvalues were observed in uncorrected measurement between the three systems, but corrected values were very similar in all cases. Correctedτvalues were found to be on the order of 103Pa s or less—one to two orders of magnitude lower than the uncorrected values, and two or more orders of magnitude lower than most published values for similar porous medium/fluid combinations. Because of the small size of the experimental system used, results suggest that at the representative elementary volume (REV) scale, the dependence of measured capillary pressure on the rate of saturation change may not be as significant as previously thought for unsaturated systems. It is hypothesized that the larger magnitude of some previously reportedτvalues may result at least in part from porous medium packing microheterogeneities that influence flow and pressure gradients in larger systems.
What Does a Doctoral Degree in Rehabilitation Counseling Bring to Speech-Language Pathology Programs?
Authors: Agan Joseph P.
Published: October 2012

In this paper, I will describe the potential contributions of interdisciplinary studies combining speech-language pathology and rehabilitation counseling in the preparation of future speech-language pathologists (SLPs). I will provide a brief introduction to the field of rehabilitation counseling and consider it from an SLP’s perspective. Next, I will describe some of my own personal experiences as they pertain to the intersecting cultures of work and disability and how these experiences influenced my practice as a master’s level SLP eventually leading to my decision to pursue a doctoral degree in rehabilitation counseling. I will describe the impact of this line of interdisciplinary study on my research and teaching. Finally, I will present some arguments about why concepts relevant to rehabilitation counseling are important to the mindset of SLPs.
IBM tries for a semiconductor superlattice
Authors: Lubkin Gloria B.
Published: October 2012

Leo Esaki, Raphael Tsu, Leroy Chang and their collaborators at IBM Research Center are trying to build a manmade superlattice, which consists of alternating layers of monocrystalline semiconductors; the arrangement results in a one-dimensional periodic potential function for the conduction electrons with a period much greater than the natural period. With such a superlattice, Esaki says, it should be possible to build amplifiers and oscillators that operate at 1 terahertz, a much higher frequency than presently available.
Managing radioactive wastes
Authors: Blomeke John O. , Nichols Jere P. , McClain William C.
Published: October 2012

Nuclear fission can provide a major share of our energy needs over the next several decades. But to fulfill this promise, we must learn to manage the radioactive wastes that arise in a multiplicity of chemical and physical forms at every stage of the nuclear fuel cycle, and to manage them by technically, politically and socially acceptable means. The problem of containing the so-called “high-level” wastes from fuel reprocessing is particularly difficult, for they remain biologically hazardous for thousands of centuries.
Experimental observation of frequency up-conversion by flash ionization
Authors: Nishida A. , Yugami N. , Higashiguchi T. , Otsuka T. , Suzuki F. , Nakata M. , Sentoku Y. , Kodama R.
Published: October 2012

We have demonstrated frequency up-conversion in the terahertz (THz) region by flash ionization, which occurs due a terahertz wave interacting with a plasma created by an ultrashort laser pulse. The upshift frequency is controlled by the plasma density. We performed a proof-of-principle experiment with a plasma creation time scale much shorter than the period of the electromagnetic wave and a plasma length longer than its wavelength. We upshifted the frequency from 0.35 to 3.5 THz by irradiating a ZnSe crystal with a Ti:sapphire laser pulse.
Quantitative measurement on optical attenuation coefficient of cell lines 5-8F and 6-10B using optical coherence tomography
Authors: Li Jianghua , Shen Zhiyuan , He Yonghong , Tu Ziwei , Xia Yunfei , Chen Changshui , Liu Songhao
Published: October 2012

Oncogenesis and metastasis of tumor are difficult to detect during the clinic therapy. To explore the optical properties of tumorigenesis and metastasis in nasopharyngeal carcinoma (NPC), we assessed the NPC cell lines 5-8F and 6-10B by optical coherence tomography (OCT): first, the OCT images of the two different types of cell pellets were captured. Second, by fitting Beer’s law to the averaged A-scans in these OCT datasets, the attenuation coefficients (μt) of the cells were extracted. The median attenuation coefficients (interquartile range (IQR)) of 5-8F and 6-10B were 6.79 mm−1 (IQR 6.52 to 7.23 mm−1) versus 8.06 mm−1 (IQR 7.65 to 8.40 mm−1), respectively (p < 0.01, df = 39). Subsequently, the results were compared with those obtained by polarization sensitive OCT, which further confirmed that the quantitative OCT analysis (by μt) could differentiate the oncogenesis and metastasis NPC cell lines in real time non-invasively.
Generating functions for generalized binomial distributions
Authors: Bergeron H. , Curado E. M. F. , Gazeau J. P. , Rodrigues Ligia M. C. S.
Published: October 2012

In a recent article generalization of the binomial distribution associated with a sequence of positive numbers was examined. The analysis of the nonnegativeness of the formal probability distributions was a key point to allow to give them a statistical interpretation in terms of probabilities. In this article we present an approach based on generating functions that solves the previous difficulties. Our main theorem makes explicit the conditions under which those formal probability distributions are always non-negative. Therefore, the constraints of non-negativeness are automatically fulfilled giving a complete characterization in terms of generating functions. A large number of analytical examples becomes available.
Effect of spin-orbit coupling on the actinide dioxides AnO2 (An=Th, Pa, U, Np, Pu, and Am): A screened hybrid density functional study
Authors: Wen Xiao-Dong , Martin Richard L. , Roy Lindsay E. , Scuseria Gustavo E. , Rudin Sven P. , Batista Enrique R. , McCleskey Thomas M. , Scott Brian L. , Bauer Eve , Joyce John J. , Durakiewicz Tomasz
Published: October 2012

We present a systematic comparison of the lattice structures, electronic density of states, and band gaps of actinide dioxides, AnO2 (An=Th, Pa, U, Np, Pu, and Am) predicted by the Heyd-Scuseria-Ernzerhof screened hybrid density functional (HSE) with the self-consistent inclusion of spin-orbit coupling (SOC). The computed HSE lattice constants and band gaps of AnO2 are in consistently good agreement with the available experimental data across the series, and differ little from earlier HSE results without SOC. ThO2 is a simple band insulator (f 0), while PaO2, UO2, and NpO2 are predicted to be Mott insulators. The remainders (PuO2 and AmO2) show considerable O2p/An5f mixing and are classified as charge-transfer insulators. We also compare our results for UO2, NpO2, and PuO2 with the PBE+U, self interaction correction (SIC), and dynamic mean-field theory (DMFT) many-body approximations.
Response behavior of diblock copolymer brushes in explicit solvent
Authors: Gong Kai , Marshall Bennett D. , Chapman Walter G.
Published: October 2012

The understanding of phase behavior of copolymer brushes is of fundamental importance for the design of smart materials. In this paper, we have performed classical density functional theory calculations to study diblock copolymer brushes (A-B) in an explicit solvent which prefers the A block to B block. With increasing B-block length (NB), we find a structural transition of the copolymer brush from mixed to collapsed, partial-exposed, and exposed structure, which is qualitatively consistent with experiments. The phase transitions are attributed to the interplay between entropic cost of folding copolymer brushes and enthalpic effect of contact between unlike components. In addition, we examine the effect of different parameters, such as grafting density (ρg), the bottom block length (NA), and the chain length of solvent (NS) on the solvent response of copolymer brushes. The transition chain length (NB) increases with decreasing ρg and NA, and a smaller solvent molecule makes the collapsed structure less stable due to its lower penetration cost. Our results provide the insight to phase behavior of copolymer brushes in selective solvents from a molecular view.
Low contact resistivity of metals on nitrogen-doped cuprous oxide (Cu2O) thin-films
Authors: Cheng Siah Sin , Seog Lee Yun , Segal Yaron , Buonassisi Tonio
Published: October 2012

Forming low-resistivity contacts on cuprous oxide (Cu2O) is an essential step toward demonstrating its suitability as a candidate solar cell material. We measure the contact resistivity of three noble metals (Au, Ag, and Pd) on sputtered Cu2O thin-films with a range of nitrogen doping levels. Using the circular transmission line model, specific contact resistivity as low as 1.1 × 10−4 Ω · cm2 is measured for Pd contacts on heavily doped Cu2O films. Temperature-dependent current-voltage measurements and X-ray photoemission spectroscopy are used to determine the barrier heights formed at metal/Cu2O interfaces. Thermionic emission is observed to dominate for undoped films, whilst field emission dominates for heavily doped films, highlighting the importance of carrier concentration on contact resistivity. Finally, we demonstrate that low contact resistivity can be achieved on heavily doped Cu2O films using Earth-abundant metals, such as Cu and Ni.
Properties of low indium content Al incorporated IZO (indium zinc oxide) deposited at room temperature
Authors: Sun Jian , Yang Weifeng , Huang Yanhua , Soon Lai Weng , Lee Alex Y. S. , Fu Wang Chiou , Gong Hao
Published: October 2012

A very low indium content (35 cation % In) a-IZO film, denoted as IZO35/65 or a-ZIO, was fabricated at room temperature. The effect of aluminum (Al) incorporation in IZO35/65 was studied systematically, and reasonably high electrical conductivity and optical transmittance were obtained. After Al doping to an optimum extent, the conductivity was interestingly increased 3 times higher than that of a-ZIO, and this effect could not be attributed to the formation of Al clusters as a further increase in Al led to a significant drop in conductivity. Nonlinear and U-shape resistivity-temperature relationship was observed for some Al doped samples. In addition, an obvious conductivity increase accompanying by the Al2O3 nano-crystallites formation was observed, which provided new evidence to the insulator-metal transition model reported by Nagarajan et al. [Nature Mater. 7, 391 (2008)] recently.
Long range coupling between defect centres in inorganic nanostructures: Valence alternation pairs in nanoscale silica
Authors: Zwijnenburg M. A. , Illas F. , Bromley S. T.
Published: October 2012

Valence alternation pair (VAP) states are formed by a closed-shell combination of two space- and charge-separated topological defect centres. These pairs of defects, although historically invoked to explain the electronic properties of bulk inorganic glassy materials (e.g., amorphous silicon dioxide) via the concept of negative-U defects, have more recently been found in a number of theoretical studies of silica surfaces and nanoscale silica clusters. Using density functional theory we systematically probe the structure and internal stability of VAPs in a number of silica nanoclusters with respect to the separation of the two constituent defect centres. We find that VAP states in nanosilica are strongly stabilised by the attractive electrostatic interaction between their separated oppositely charged component defects such that VAPs can persist up to an internal separation of a least 1.5 nanometres. Beyond this distance VAPs become unstable with respect to an open-shell combination of topological defects, virtually indistinguishable from two isolated open-shell defect centres. Finally, we theoretically analyse the possibility of experimental observation of VAP states through their infra-red vibrational spectra.