bluuebunny/crossref_metadata_2025 huggingface dataset:
Allelic loss of the loci containing the androgen synthesis gene, StAR, is prognostic for relapse in intermediate‐risk prostate cancer
Authors: Locke Jennifer A. , Zafarana Gaetano , Malloff Chad A. , Lam Wan L. , Sykes Jenna , Pintilie Melania , Ramnarine Varune Rohan , Meng Alice , Ahmed Omer , Jurisica Igor , Guns Emma Tomlinson , van der Kwast Theo , Milosevic Michael , Bristow Robert G.
Published: December 2011

BACKGROUND

Androgen deprivation therapy (ADT) and novel agents targeting the androgen synthesis axis (e.g., abiraterone acetate) are adjuvant therapies that are currently, or may in the future be, combined with radiotherapy to reduce the chance of disease relapse. Little is known about allelic loss or gain pertaining to genes associated with the androgen synthesis axis and whether this is prognostic in patients who receive localized radiotherapy. In this hypothesis generating study, we conducted an array comparative genomic hybridization (aCGH) analysis of 33 androgen synthesis genes to identify potential prognostic factors for radiotherapy outcome.

METHODS

aCGH analysis of tumor DNA prospectively derived from frozen needle biopsies of 126 men with intermediate‐risk disease who underwent image‐guided radiotherapy (IGRT) to a mean dose of 76.4 Gy was conducted. Statistical analyses were conducted for allelic loss or gain in genes as potential prognostic factors relative to prostate specific antigen, Gleason‐score, and T‐category.

RESULTS

We observed that allelic losses of loci containing the genes StAR and HSD17B2 were associated with increased genetic instability (as determined by percentage genome alteration). On multivariate analyses these loci were prognostic for biochemical disease‐free relapse (StAR: HR = 2.84, 95% CI: 1.44–5.61, P = 0.00269; HSD17B2: HR = 1.97, 95% CI: 1.06–3.64, P = 0.031). The results were validated in a surgical cohort of 131 intermediate‐risk patients.

CONCLUSIONS

Allelic losses of the loci containing StAR and HSD17B2 have significant prognostic value for intermediate‐risk prostate cancer. With this hypothesis generating information future studies should test StAR and HSD17B2 losses as biomarkers of androgen response in combined modality protocols. Prostate 72:1295–1305, 2012. © 2011 Wiley Periodicals, Inc.
Extensions of DFTB to investigate molecular complexes and clusters
Authors: Rapacioli Mathias , Simon Aude , Dontot Léo , Spiegelman Fernand
Published: December 2011

Molecular complexes and clusters provide bridges between molecular and solid states physics. Containing tens to few thousands of atoms, such systems can hardly be approached via traditionalab initiowavefunction based methods at the moment. Density functional theory (DFT) and density functional based tight binding methods (DFTB) have strongly developed with respect to computational efficiency to cover this size range. However both DFT and currently implemented DFTB face difficulties to describe realistically and accurately the typical interactions met in molecular clusters, in particular long range interactions such as Coulomb interactions between distant charge fluctuations, charge resonance in ionic clusters, and van der Waals interactions. The present article aims at providing an overview of how extensions of DFTB can circumvent some of the above deficiencies and turn out to be realistic and efficient tools to investigate the properties of molecular clusters and complexes, focusing on structural, electronic, energetic, and spectroscopic properties.
Excited state properties of Si quantum dots
Authors: Zhang Rui‐Qin , De Sarkar Abir , Niehaus Thomas A. , Frauenheim Thomas
Published: December 2011

Silicon is the cornerstone of the semiconductor industry. In the nanoscale, the surface gains considerable significance due to the large surface to volume ratio. Recent theoretical advances in the investigation of the excited state properties of silicon quantum dots (QDs) are reviewed in this article. The origin of optical properties in silicon QDs is attributed to the tetrahedral crystalline structure in the Si nanostructures. Consequently, passivating the surfaces of these Si nanostructures by a suitable species turns out to be the most effective avenue for the retention of their tetrahedral structural symmetry and in turn their photoluminescence (PL) properties. The passivating agent and the extent of surface passivation need to be chosen very judiciously for the purpose of realizing the practical applications of the dots. Structural relaxation in the excited state induces Stokes shift, which varies with the particle size, the degree of surface passivation, and the nature of the passivating species. Stokes shift needs to be minimized for maximizing the PL efficiency of the QDs. All these intermingled issues are briefly addressed in the article.
A‐site magnetism in A‐site‐ordered perovskite‐structure oxides
Authors: Shimakawa Yuichi , Saito Takashi
Published: December 2011

A‐site‐ordered perovskite‐structure oxides AA′3B4O12 with Cu2+ ions at the A′ site are highlighted. Some new compounds were synthesized under high‐pressure and high‐temperature conditions. With nonmagnetic ions at the B site, only the Cu2+ spins at the A′ site contribute to the magnetic properties, providing an intriguing magnetism system that has a cubic S = 1/2 spin sublattice. When the A‐site ion is nonmagnetic, either ferromagnetism (CaCu3Ge4O12 and CaCu3Sn4O12) or antiferromagnetism (CaCu3Ti4O12) of Cu2+ spins arises. The ferromagnetic Cu–Cu direct‐exchange interaction and the antiferromagnetic Cu–O–Ti–O–Cu superexchange interaction are mutually competitive, and a perfect balance of the interactions in a solid‐solution sample causes unusual instability resulting in a magnetic tri‐critical point. Introducing magnetic lanthanide (Ln) ions into the A site was expected to produce A–A′ magnetic interaction, and in both the antiferromagnetic (Ln2/3Cu3Ti4O12) and ferromagnetic [LnCu3(Ge3/4Ga1/4)4O12] compounds the A′‐site Cu2+ spins are ordered but the magnetic interactions between the A‐ and A′‐site magnetic sublattices are very weak.

magnified image

Ferromagnetic (left) and antiferromagnetic (right) spin structures of A‐site‐ordered perovskite‐structure oxides, AA′3B4O12.
Zeche Nordstern: Aufstockung Schacht II
Authors: Dietz Markus , Bott Markus
Published: December 2011

Die Zeche Nordstern in Gelsenkirchen‐Heßler wurde 1868 als erste Zeche nördlich der Emscher errichtet. In den Jahren 1926/27 und 1930 erweiterten die Architekten Kremmer und Schupp die Zeche in der ihnen eigenen funktionalen Architektur, welche schon das Bild der benachbarten Zeche Zollverein prägt. Der Förderturm Schacht II wurde 1951 nach der Planung von Fritz Schupp als Stahlfachwerkkonstruktion mit einer vorgeblendeten Mauerwerksfassade gebaut. Die historische Aufnahme (Bild 1) zeigt den Förderturm Schacht II während der Bauphase. Der gesamte Stahlbau wurde nicht gegen Korrosion geschützt, man ging davon aus, dass nach Ende der Kohleförderung der Schacht abgebaut wird. Aus diesem Schacht wurde bis zum Jahre 1993 Steinkohle aus bis zu 1000 m Tiefe gefördert.

Der Beitrag beschreibt die Aufstockung von fünf Etagen auf den bestehenden 62 m hohen Schacht II und die Errichtung des zugehörigen Erschließungsbauwerkes. Die Aufstockung gliedert sich wie folgt: Die Ebene auf 64,78 m ist als Konferenzbereich geplant, die oberen drei Ebenen werden zu Büroetagen ausgebaut. In der bisherigen Dachebene des Schachtes II, am Übergang von Bestand zur Aufstockung, wurde ein Splitlevel als Verteiler‐ und Technikebene angeordnet. Dieses ist wie folgt aufgebaut: Die Ebene auf 61,61 m ist eine Technikebene mit Lamellenfassade; der tiefer liegende Bereich auf 57,94 m ist ein Auditorium, welches als Kubus in den ehemalige 10 m hohen Maschinenraum eingehängt ist. Ein für dieses Hochhaus notwendiges Erschließungsbauwerk aus Stahlbeton wurde vor der Ostwand des Bestandsturmes errichtet. Nach der Aufstockung hat das Bauwerk eine Höhe von 84 m. Auf dem Dach, in einer Höhe von 80,38 m, befindet sich eine öffentlich zugängliche Terrasse.
Untersuchungen zum Korrosionsschutz von Kanten an Stahlkonstruktionen – Ergebnisse der Laborprüfungen (Teil 2)
Authors: Momber Andreas W. , Buchbach Sascha , Plagemann Peter
Published: December 2011

Im Rahmen von Laborprüfungen wurde die Korrosionsschutzwirkung organischer Beschichtungssysteme an Kanten von Stahlkonstruktionen untersucht. Die Kanten waren mit verschiedenen mechanischen und thermischen Verfahren vor dem Beschichten gerundet worden. Es kamen drei verschiedene Beschichtungssysteme zum Einsatz, darunter ein sogenanntes kantenfreundliches System. Für die Beurteilung der Korrosionsschutzwirkung wurden drei Kennwerte herangezogen: Kantenüberdeckungsgrad, Barrierewiderstand der Beschichtung und Antikorrosiv‐Effekt. Die Prüfungen umfassten Messungen der Trockenschichtdicken an Kanten und Flächen, Untersuchungen mittels elektrochemischer Impedanzspektroskopie (EIS) und beschleunigte Alterungsprüfungen in einer Wellentank‐Simulationskammer. Im Teil 1 des Beitrags [34] waren Konzeption und Durchführung der Prüfungen sowie die verwendeten Prüfkörper und Korrosionsschutzsysteme beschrieben worden. Über die Ergebnisse der Laborprüfungen wird im vorliegenden Teil 2 berichtet.

Investigations into the corrosion protection on edges of steel constructions – Results of laboratory investigations (Part 2). Based on laboratory tests, the corrosion protection capability of organic coating systems on edges of steel constructions was investigated. The edges were rounded with different mechanical and thermal tools. Three different coating systems were considered, whereby one of the systems was a so‐called edge retentive system. Three criteria were utilized in order to assess the corrosion protection capability: edge coverage degree, barrier resistance of the coating systems, and an anticorrosive effect. The tests included DFT measurements on edges and areas, electrochemical impedance spectroscopy (EIS) measurements and accelerated ageing tests in a wave tank simulation chamber. Part 1 of the paper covered the general experimental design and details of the experimental procedure, whereas the present Part 2 reports about results of the test programme.
Sind Vorbehalte gegenüber einer Verwendung verzinkter Bauteile in Hallenbädern gerechtfertigt?
Authors: Nürnberger Ulf
Published: December 2011

In der DIN EN ISO 12944, Teil 2, wird die Korrosionsbelastung in Hallenbädern einer Korrosivitätskategorie C4 (starke Korrosionsbelastung) zugeordnet. Folgt man den Angaben dieser Norm, dann sollte bei verzinkten Bauteilen der jährliche Zinkabtrag in einer Hallenschwimmbadatmosphäre mehrere Mikrometer betragen. Ein solches Korrosionsverhalten stimmt jedoch nicht mit den baupraktischen Erfahrungen überein.

Im vorliegenden Beitrag wird die Badatmosphäre aus korrosionschemischer Sicht betrachtet. Weiterhin werden Untersuchungen an verzinkten Bauteilen in bis zu 40 Jahre alten Hallenschwimmbädern dargestellt, und es werden Ergebnisse zur langzeitigen Zinkkorrosion in einem im Hinblick auf die Korrosionsbeanspruchung eher kritischen Bad dargelegt. Danach ist die Zinkkorrosion in den mit Leitungswasser betriebenen normalen Hallenschwimmbädern erheblich geringer als in der DIN EN ISO 12944 ausgewiesen. Es wird ein Vorschlag unterbreitet, diesem Sachverhalt im Regelwerk Rechnung zu tragen.

Are reservations against the usage of galvanized building elements for indoor pools justified? According to DIN EN ISO 12944, part 2, the corrosion exposure in indoor pools falls under corrosion category C4 (severe corrosion exposure). Consequently, the zinc corrosion of the galvanized building elements exposed to an indoor pool atmosphere would amount to several micrometers. However, this kind of corrosion behaviour does not correspond with the practical building experiences.

This paper pertains to chemical corrosion in a pool atmosphere. Furthermore, the investigations of galvanized building elements in up to 40‐year‐old indoor swimming pools are summarized and the results of long‐time zinc corrosion in a rather critical pool atmosphere are presented. Accordingly, the zinc corrosion in a normal indoor pool using tap water is substantially lower than stated in DIN EN ISO 12944. It is proposed that account should be taken pertaining to this issue.
Adaptation to climate change by organizations
Authors: Berkhout Frans
Published: December 2011

Organizations will be central actors in societal adaptation to climate variability and change. But highly simplified assumptions are often made about the response of organizations to the stimulus of perceived or experienced climate change. This paper reviews recent literature, arguing that three approaches are applied in studies of organizational adaptation: utility‐maximizing, behavioral, and institutional approaches. The paper argues that adaptive responses by organizations are conditioned by the processes of perception, evaluation, enactment, and learning by organizations. Organizational adaptation involves adjustments in each of these processes. The extent to which adaptive measures are taken by organizations will be influenced both by endogenous factors, such as the capability to innovate and attitudes to risk, as well as by the external economic and institutional context. Willingness to exercise available adaptation options will vary between organizations. Evidence of organizational adaptation from case studies and meta‐analyses is reviewed. WIREs Clim Change 2012, 3:91–106. doi: 10.1002/wcc.154

This article is categorized under:

Vulnerability and Adaptation to Climate Change > Institutions for Adaptation
The maternal muscle determinant in the ascidian egg
Authors: Nishida Hiroki
Published: December 2011

Muscle formation in ascidian embryos has been investigated for more than a century as a representative example of cell fate specification by localized maternal factors within the egg cytoplasm. Observations of colored cytoplasm in combination with micromanipulation techniques have suggested the presence of a muscle‐forming factor. The molecular basis has been elucidated with the discovery of macho‐1. macho‐1 mRNA is already present in the unfertilized egg, and translocates to the posterior region of the egg during ooplasmic movements. It encodes a zinc‐finger transcription factor that positively regulates the expression of target genes. macho‐1‐binding cis‐elements have been identified in muscle‐specific zygotic genes. Maternally localized macho‐1 appears to have originated in the ascidian lineage, but it activates a muscle‐forming developmental program that is shared by the vertebrates. macho‐1 is also involved in establishment of the anterior–posterior axis as a competence factor in mesenchyme induction in the posterior region. It is suggested that translation of the macho‐1 protein is initiated at the eight‐cell stage, and that the protein is inherited by all descendant blastomeres of the posterior‐vegetal region. The macho‐1 activities in nonmuscle descendants are suppressed or modified by cell interactions during the cleavage stages. In addition to the primary muscle specified by maternal macho‐1, ascidian embryos develop secondary muscle, whose fate is determined by cell interactions. Dozens of maternal mRNAs show similar localization to macho‐1, and these are known as postplasmic/PEM RNAs, being also involved in various posterior‐specific developmental events. Evolutionary aspects relevant to macho‐1 and tail muscle formation are also discussed in this article. WIREs Dev Biol 2012, 1:425–433. doi: 10.1002/wdev.22

This article is categorized under:

Establishment of Spatial and Temporal Patterns > Cytoplasmic Localization

Early Embryonic Development > Fertilization to Gastrulation

Comparative Development and Evolution > Body Plan Evolution
Anterior–posterior patterning in early development: three strategies
Authors: Kimelman David , Martin Benjamin L.
Published: December 2011

The anterior–posterior (AP) axis is the most ancient of the embryonic axes and exists in most metazoans. Different animals use a wide variety of mechanisms to create this axis in the early embryo. In this study, we focus on three animals, including two insects (Drosophila and Tribolium) and a vertebrate (zebrafish) to examine different strategies used to form the AP axis. While Drosophila forms the entire axis within a syncytial blastoderm using transcription factors as morphogens, zebrafish uses signaling factors in a cellularized embryo, progressively forming the AP axis over the course of a day. Tribolium uses an intermediate strategy that has commonalities with both Drosophila and zebrafish. We discuss the specific molecular mechanisms used to create the AP axis and identify conserved features. WIREs Dev Biol 2012, 1:253–266. doi: 10.1002/wdev.25

This article is categorized under:

Signaling Pathways > Global Signaling Mechanisms

Early Embryonic Development > Gastrulation and Neurulation

Early Embryonic Development > Development to the Basic Body Plan

Comparative Development and Evolution > Body Plan Evolution
A niche for Drosophila neuroblasts?
Authors: Chai Phing Chian , Chia William , Cai Yu
Published: December 2011

Stem cells, which can self‐renew and give rise to differentiated daughters, are responsible for the generation of diverse cell types during development and the maintenance of tissue/organ homeostasis in adulthood. Thus, the precise regulation of stem‐cell self‐renewal and proliferative potential is a key aspect of development. The stem‐cell niche confers such control by concentrating localized factors including signaling molecules which favor stem‐cell self‐renew and regulate stem‐cell proliferation in line with developmental programs. In contrast, Drosophila neuroblasts (NBs), often referred to as neural stem cells/progenitors, can undergo asymmetric cell division to self‐renew and produce differentiated daughters even in isolation (or in culture). Furthermore, these isolated NBs can also progress through an intrinsically regulated temporal series (of transcription factor expression) to generate diverse cell types in vitro. These data argue that NBs may depend only to a limited extent, if at all, on local environment (a niche) for their maintenance. On the other hand, there is increasing evidence which indicate that the interaction between NBs and their surrounding glia is critical for the control of NB proliferative potential and these glia, in conjunction with systemic regulation, perform the niche function to regulate NB behavior. Thus, these observations emphasize the importance of coordinated local microenvironment (niche activity) and systemic environment (global activity) on the regulation of NB behavior in vivo, and suggest NBs may conform to an alternative stem‐cell/progenitor maintenance model. WIREs Dev Biol 2012, 1:307–314. doi: 10.1002/wdev.27

This article is categorized under:

Nervous System Development > Flies

Adult Stem Cells, Tissue Renewal, and Regeneration > Tissue Stem Cells and Niches

Adult Stem Cells, Tissue Renewal, and Regeneration > Environmental Control of Stem Cells
Identification of RNA–protein interaction networks using PAR‐CLIP
Authors: Ascano Manuel , Hafner Markus , Cekan Pavol , Gerstberger Stefanie , Tuschl Thomas
Published: December 2011

All mRNA molecules are subject to some degree of post‐transcriptional gene regulation (PTGR) involving sequence‐dependent modulation of splicing, cleavage and polyadenylation, editing, transport, stability, and translation. The recent introduction of deep‐sequencing technologies enabled the development of new methods for broadly mapping interaction sites between RNA‐binding proteins (RBPs) and their RNA target sites. In this article, we review crosslinking and immunoprecipitation (CLIP) methods adapted for large‐scale identification of target RNA‐binding sites and the respective RNA recognition elements. CLIP methods have the potential to detect hundreds of thousands of binding sites in single experiments although the separation of signal from noise can be challenging. As a consequence, each CLIP method has developed different strategies to distinguish true targets from background. We focus on photoactivatable ribonucleoside‐enhanced CLIP, which relies on the intracellular incorporation of photoactivatable ribonucleoside analogs into nascent transcripts, and yields characteristic sequence changes upon crosslinking that facilitate the separation of signal from noise. The precise knowledge of the position and distribution of binding sites across mature and primary mRNA transcripts allows critical insights into cellular localization and regulatory function of the examined RBP. When coupled with other systems‐wide approaches measuring transcript and protein abundance, the generation of high‐resolution RBP‐binding site maps across the transcriptome will broaden our understanding of PTGR and thereby lead to new strategies for therapeutic treatment of genetic diseases perturbing these processes. WIREs RNA 2012, 3:159–177. doi: 10.1002/wrna.1103

This article is categorized under:

RNA Evolution and Genomics > Computational Analyses of RNA

RNA Interactions with Proteins and Other Molecules > Protein–RNA Recognition

RNA Interactions with Proteins and Other Molecules > RNA–Protein Complexes

RNA Methods > RNA Analyses in Cells
Effects of antiviral therapy on long‐term outcome after liver resection for hepatitis B virus‐related hepatocellular carcinoma
Authors: Urata Yorihisa , Kubo Shoji , Takemura Shigekazu , Uenishi Takahiro , Kodai Shintaro , Shinkawa Hiroji , Sakae Masayuki , Kaneda Kazuhisa , Ohata Kazunori , Nozawa Akinori , Suehiro Shigefumi
Published: December 2011

Background/purpose

We investigated the effects of nucleos(t)ide analogues (NAs) on long‐term outcome in patients following curative treatment for hepatitis B virus (HBV)‐related hepatocellular carcinoma (HCC).

Methods

This study involved 70 of the 76 patients who had undergone liver resection for HBV‐related HCC in our department; 6 patients were excluded due to non‐curative resection or advanced cancer. The 70 patients were divided into three groups, as follows: 13 patients with high serum concentration of HBV DNA (⩾4 log10 copies/mL) and no antiviral therapy (high viral group); 46 patients who received antiviral therapy during the serial follow up (antiviral therapy group) because of high viral concentration (⩾4 log10 copies/mL); and 11 patients with low serum concentration of HBV DNA (<4 log10 copies/mL) and no antiviral therapy (low viral group).

Results

Tumor‐free survival rate was significantly higher in the low viral group than in the high viral group (P = 0.0058). Multivariate analysis revealed that a high serum concentration of HBV DNA (⩾4 log10 copies/mL) (risk ratio 6.717, 95% confidence interval 1.435–31.434, P = 0.0156) was an independent risk factor for a short tumor‐free survival time. Tumor‐free survival rate was significantly higher in the antiviral therapy group than in the high viral group (P = 0.0478). Multivariate analysis revealed that presence of multiple tumors (risk ratio 2.857, 95% confidence interval 1.403–5.816, P = 0.0038) was an independent risk factor for a short tumor‐free survival time. The cumulative survival rate was significantly higher in the antiviral therapy group than in the high viral group (P = 0.0025). Multivariate analysis revealed that not undergoing antiviral therapy (risk ratio 0.121, 95% confidence interval 0.024–0.608, P = 0.0104) was an independent risk factor for a short survival time.

Conclusions

A high serum concentration of HBV DNA (⩾4 log10 copies/mL) was a strong risk factor for HCC recurrence after resection of HBV‐related HCC. Antiviral therapy with NAs improved the long‐term outcome after resection of HBV‐related HCC in patients with high serum concentrations of HBV DNA.
Proposed indications for limited resection of early ampulla of Vater carcinoma: clinico‐histopathological criteria to confirm cure
Authors: Aiura Koichi , Hibi Taizo , Fujisaki Hiroto , Kitago Minoru , Tanabe Minoru , Kawachi Shigeyuki , Itano Osamu , Shinoda Masahiro , Yagi Hiroshi , Masugi Yohei , Sakamoto Michiie , Kitagawa Yuko
Published: December 2011

Background

Limited resection is reserved for patients with high operative risk or benign adenomas. We aimed to define indications for limited resection of early ampulla of Vater carcinoma with curative intent through detailed preoperative examinations and histopathological evaluations.

Methods

We performed a retrospective cohort study of all consecutive Japanese patients who underwent resection for ampulla of Vater neoplasms at our hospital from 1986 to 2010.

Results

A total of 75 patients were identified. Moderately/poorly differentiated histology, lympho‐vascular/perineural invasion, and duodenal/pancreatic invasion were significant risk factors for lymph node metastases. Macroscopically, non‐exposed protruded‐ or ulcerative‐type disease did not correlate directly with lymph node metastases; however, these tumor types were associated with other invasive features. In a subset of early carcinomas fulfilling the conditions of exposed protruded adenoma or papillary/well‐differentiated adenocarcinoma determined by endoscopic biopsy, negative duodenal invasion determined by endoscopic ultrasonography, no tumor infiltration into the pancreatic duct determined by intraductal ultrasound, and diameter of the pancreatic duct ⩽3 mm determined by endoscopic retrograde cholangiopancreatography (N = 11), the incidence of lymph node metastasis and tumor infiltration into the pancreatic duct was 0%.

Conclusion

Strictly selected patients with early ampulla of Vater carcinomas may benefit from limited resection if the resected specimen is evaluated to confirm all histopathological criteria.
The Impact of Housing Stressors on the Mental Health of a Low-Income African-American Population
Authors: Green Rodney D. , Kouassi Marie , Venkatachalam Padma , Daniel Johnnie
Published: December 2011

Health and disease reflect broad social conditions including economic, environmental, and cultural components. The impact of challenging housing conditions experienced by low-income African American households on their mental health is an example of this principle. Do physical housing conditions, the presence of roaches and rodents, plumbing defects, and heating/cooling problems contribute to mental health dysfunction such as being depressed, feeling worried, feeling sad, feeling helpless, and feeling emotionally upset? To address this research question, a sample of 128 households that originally lived in public housing in Washington, D.C. were surveyed. These households had been relocated to other low-income housing during the demolition and reconstruction phase of a HOPE VI project, some to alternative public housing developments and others to private units based on vouchers. The survey included self-reports by heads of household on their housing conditions and mental health status using Likert scales. The survey also asked participants for demographic, socio-economic, and physical health data and for information on neighborhood characteristics. Correlation and regression analyses were used to estimate the impact of building structure, building systems, neighborhood characteristics, physical health, and socio-economic/demographic variables on mental health stresses. Specific housing issues included the number of bedrooms, plumbing, heating, cooling, rodents, roaches, and building security (the independent variables). Mental health stresses (the dependent variables) included feeling depressed, nervous, anxious, sad, helpless, and having trouble concentrating. Several alternative specifications and models were used and estimated. They generally demonstrated strong overall explanatory value. The findings from these models suggested that challenging housing conditions significantly contributed to many mental health disorders. For example, in the 2SLS model of “problem being depressed”, the condition of the apartment (β =0.278, t=2.022) and plumbing (β = 0.182, t=2.145) were significant and the model's explanatory power was reasonable with an adjusted R2=0.221. Many non-housing control variables were also significantly associated with mental health challenges.
The Impact of Mass Incarceration on the Lives of African American Women
Authors: Cox Robynn J. A.
Published: December 2011

This paper examines the consequences of mass incarceration on various aspects of the lives of African-American women. In particular, it seeks to determine how the historically high growth rate in the prison population over the past 30 years has affected employment outcomes, family relationships, and the physical and mental health of Black women who have been incarcerated.
The Quality of Male Fertility Data in Major U.S. Surveys
Authors: Joyner Kara , Peters H. Elizabeth , Hynes Kathryn , Sikora Asia , Taber Jamie Rubenstein , Rendall Michael S.
Published: December 2011

Researchers continue to question fathers’ willingness to report their biological children in surveys and the ability of surveys to adequately represent fathers. To address these concerns, this study evaluates the quality of men’s fertility data in the 1979 and 1997 cohorts of the National Longitudinal Survey of Youth (NLSY79 and NLSY97) and in the 2002 National Survey of Family Growth (NSFG). Comparing fertility rates in each survey with population rates based on data from Vital Statistics and the U.S. Census Bureau, we document how the incomplete reporting of births in different surveys varies according to men’s characteristics, including their age, race, marital status, and birth cohort. In addition, we use Monte Carlo simulations based on the NSFG data to demonstrate how birth underreporting biases associations between early parenthood and its antecedents. We find that in the NSFG, roughly four out of five early births were reported; but in the NLSY79 and NLSY97, almost nine-tenths of early births were reported. In all three surveys, incomplete reporting was especially pronounced for nonmarital births. Our results suggest that the quality of male fertility data is strongly linked to survey design and that it has implications for models of early male fertility.
IGF‐1 receptor is down‐regulated by sunitinib induces MDM2‐dependent ubiquitination
Authors: Shen Hongchang , Fang Yan , Dong Wei , Mu Xueru , Liu Qi , Du Jiajun
Published: December 2011

The insulin like growth factor receptor subtype 1(IGF‐1R) plays an important role in cancers transformation and progression. The aim is to investigate the effects of sunitinib on IGF‐1R cell signaling transduction, especially on receptor phosphorylation and ubiquitination. In HEK293 cells, IGF‐1R signaling pathways are activated in response to IGF‐1, which induces obvious phosphorylations of receptor tyrosine and Akt, ERK. However, the phosphorylations of receptor tyrosine, Akt and ERK were significant inhibited by sunitinib. We found that both IGF‐1 and sunitinib obviously down regulated the IGF‐1R expression. For analysis the ubiquitination, HEK293 cells were simulated with 100 ng/ml IGF‐1 or 10 nM sunitinib for 10 min after serum starvation for 24 h. Both IGF‐1 and sunitinib could obviously induce the IGF‐1R ubiquitination at 10 min compared with control (only serum free, no stimulation), indicating IGF‐1 and sunitinib down‐regulate the IGF‐1R by increasing the receptor degradation through ubiquitination dependent proteasome pathway. We also found that MDM2 combined to IGF‐1R in response to sunitinib stimulation. To confirm it, HEK293 cells were transfected with human HA‐MDM2 (+MDM2) or siRNA to MDM2 (−MDM2). Following 24 h serum starvation, cells were stimulated with 10 nM sunitinib for 10 min. In over‐expressed MDM2 cells, IGF‐1R was more ubiquitinated than that in mock‐transfected cells (control), and no ubiquitination in −MDM2 cells. These results mean that sunitinib mediates ubiquitination of IGF‐1R dependent on MDM2. In summary, sunitinib could block signaling transduction and mediate degradation of IGF‐1R.
HNO3−NHx, H2SO4−NHx, CH(O)OH−NHx, and CH3C(O)OH−NHx complexes and their role in the formation of condensation nuclei
Authors: Clark Jared , Kumbhani Sambhav , Hansen Jaron C. , Francisco Joseph S.
Published: December 2011

The formation of sulfuric acid (H2SO4), nitric acid (HNO3), acetic acid (CH3C(O)OH), and formic acid (HC(O))H) complexes with ammonia (NH3), amidogen radical (NH2), and imidogen radical (NH) was studied using natural bond orbital calculations. The equilibrium structures, binding energies, and harmonic frequencies were calculated for each acid-NHx complex using hybrid density functional (B3LYP) and second-order Møller-Plesset perturbation approximation methods with the 6-311++G(3df,3pd) basis set. The results presented here suggest that the effect of NH2 on the formation of new condensation nuclei will be similar to that of NH3, but to a lesser degree and confined primarily to complexes with H2SO4 and HNO3. The NH radical is not expected to play a significant role in the formation of new atmospheric condensation nuclei.
Computing the energy of a water molecule using multideterminants: A simple, efficient algorithm
Authors: Clark Bryan K. , Morales Miguel A. , McMinis Jeremy , Kim Jeongnim , Scuseria Gustavo E.
Published: December 2011

Quantum Monte Carlo (QMC) methods such as variational Monte Carlo and fixed node diffusion Monte Carlo depend heavily on the quality of the trial wave function. Although Slater-Jastrow wave functions are the most commonly used variational ansatz in electronic structure, more sophisticated wave functions are critical to ascertaining new physics. One such wave function is the multi-Slater-Jastrow wave function which consists of a Jastrow function multiplied by the sum of Slater determinants. In this paper we describe a method for working with these wave functions in QMC codes that is easy to implement, efficient both in computational speed as well as memory, and easily parallelized. The computational cost scales quadratically with particle number making this scaling no worse than the single determinant case and linear with the total number of excitations. Additionally, we implement this method and use it to compute the ground state energy of a water molecule.
A novel scaling law relating the geometrical dimensions of a photocathode radio frequency gun to its radio frequency properties
Authors: Lal Shankar , Pant K. K. , Krishnagopal S.
Published: December 2011

Developing a photocathode RF gun with the desired RF properties of the π-mode, such as field balance (eb) ∼1, resonant frequency fπ = 2856 MHz, and waveguide-to-cavity coupling coefficient βπ ∼1, requires precise tuning of the resonant frequencies of the independent full- and half-cells (ff and fh), and of the waveguide-to-full-cell coupling coefficient (βf). While contemporary electromagnetic codes and precision machining capability have made it possible to design and tune independent cells of a photocathode RF gun for desired RF properties, thereby eliminating the need for tuning, access to such computational resources and quality of machining is not very widespread. Therefore, many such structures require tuning after machining by employing conventional tuning techniques that are iterative in nature. Any procedure that improves understanding of the tuning process and consequently reduces the number of iterations and the associated risks in tuning a photocathode gun would, therefore, be useful. In this paper, we discuss a method devised by us to tune a photocathode RF gun for desired RF properties under operating conditions. We develop and employ a simple scaling law that accounts for inter-dependence between frequency of independent cells and waveguide-to-cavity coupling coefficient, and the effect of brazing clearance for joining of the two cells. The method has been employed to successfully develop multiple 1.6 cell BNL/SLAC/UCLA type S-band photocathode RF guns with the desired RF properties, without the need to tune them by a tiresome cut-and-measure process. Our analysis also provides a physical insight into how the geometrical dimensions affect the RF properties of the photo-cathode RF gun.
Effect of built-in electric field on the temperature dependence of transition energy for InP/GaAs type-II superlattices
Authors: Singh S. D. , Porwal S. , Srivastava A. K. , Sharma T. K. , Oak S. M.
Published: December 2011

Built-in electric field in InP/GaAs type-II superlattice structures considerably modifies the temperature dependence of the ground state (GS) transition energy in photoreflectance measurements. For moderate electric fields, the temperature dependence of the GS transition energy follows the bandgap of the GaAs barrier layer, and it decreases at a faster rate than that of the GaAs material in the case of larger values of built-in electric field. The GS excitonic feature red shifts with quantum well thickness, confirming that it originates from the superlattice structure. Further, the variation of the broadening parameter with temperature is governed by the scattering of electrons with longitudinal optical phonons.
Direct measurement of plasmon propagation lengths on lithographically defined metallic waveguides on GaAs
Authors: Bracher G. , Schraml K. , Jakubeit C. , Kaniber M. , Finley J. J.
Published: December 2011

We present optical investigations of rectangular surface plasmon polariton (SPP) waveguides (WGs) lithographically defined on GaAs substrates. The plasmon propagation length is directly determined using a confocal microscope, with independent polarization control in both excitation and detection channels. Surface plasmon polaritons are launched along the waveguide using a lithographically defined defect at one end. At the remote end of the waveguide, they scatter into the far-field, where they are imaged using a CCD camera. By monitoring the length dependence of the intensity of scattered light from the waveguide end, we directly extract the propagation length, obtaining values ranging from LSPP = 10 to 40 μm depending on the waveguide width (ωWG = 2–5 μm) and excitation wavelength (760–920 nm). Results are in good accord with theoretical expectations demonstrating the high quality of the lithographically defined structures. The results obtained are of strong relevance for the development of future semiconductor based integrated plasmonic technologies.
Ballistic phonon thermal transport in a cylindrical semiconductor nanowire modulated with nanocavity
Authors: Xie Zhong-Xiang , Chen Ke-Qiu , Tang Li-Ming
Published: December 2011

By developing the mode matching numerical technique, we investigate the ballistic phonon thermal transport through a cylindrical semiconductor nanowire modulated with a coupling nanocavity. It is found that the phonon transmission exhibits the periodical transmission properties in low frequency region. The resonant transmission and reflection behaviors of acoustic phonon modes at particular energy can be observed. In the limit T → 0, the thermal conductance approaches the universal quantum value π2kB2T/3h, and such a quantum is robust against all geometrical parameters. However, the thermal conductance exhibits nonmonotonic behaviors with increasing temperature and can be modulated by adjusting geometrical parameters of the nanocavity.
Determination of miscibility in MgO-ZnO nanocrystal alloys by x-ray absorption spectroscopy
Authors: Limpijumnong Sukit , Jutimoosik Jaru , Palakawong Nirawith , Klysubun Wantana , Nukeaw Jiti , Du Mao-Hua , Rujirawat Saroj
Published: December 2011

The local structure of MgxZn1−xO nanocrystals is studied using synchrotron x-ray absorption near edge structures (XANES) over the full range of composition, from x = 0 to 1. Mg and Zn K-edges XANES measurements allow us to selectively study the local environments around Mg and Zn atoms in these nanocrystalline samples. Our results indicate that, for MgO-ZnO alloys, Zn is highly miscible in the rocksalt domain (i.e., up to ∼50 at. %) while the miscibility of Mg in the wurtzite domain is much less but is still substantial (i.e., up to ∼20 at. %). The simulated XANES spectra, based on first principles methods, are consistent with the observed spectra, confirming our finding. Because it is short-ranged and element-specific, the technique is useful for local structure and crystal phase determination of nanostructures, quantum dots, and mixed-phase alloys in general.
Revealing low-temperature atomic ordering in bulk Co-Pt with the high-throughput ab-initio method
Authors: Chepulskii Roman V. , Curtarolo Stefano
Published: December 2011

The low-temperature phase diagram of bulk Co-Pt is studied with a high-throughput ab-initio method. Global, hcp-, and fcc-restricted convex hulls are constructed to evaluate stable and metastable phases. It is found that fcc-L10 is energetically degenerate with hcp-B19. Both structures are unstable with respect to phase decomposition into hcp-D019↔fcc-β2 at low temperature. Furthermore, L10 is an adaptive structure on the fcc-restricted convex hull which relates to the low energies of antiphase boundaries. Fcc-L12 is energetically degenerate with fcc-D023 for both Co3Pt and CoPt3. L12-Co3Pt and L10-CoPt belong to the fcc-restricted convex hull. They might stabilize above the Co hcp/fcc transition and remain kinetically frozen below. L12-CoPt3 is energetically well above the convex hull. Its experimental observation may result from yet unexplained finite-temperature effects.
Nonlinear lower hybrid oscillations in a cold viscous plasma
Authors: Maity Chandan , Chakrabarti Nikhil
Published: December 2011

An analytical description of nonlinear lower hybrid oscillations in a cold quasi-neutral plasma in the presence of viscosity is presented in one spatial dimension by using Lagrangian variables. By treating viscosity coefficients of the electron and ion fluids as inversely proportional to their respective densities, an exact solution is obtained. It is found that the damping rate of such oscillations is directly proportional to the effective viscosity coefficients of electron and ion fluids. A possible implication of such solutions is briefly outlined.
Control of selective adsorption behavior of Ti-binding ferritin on a SiO2 substrate by atomic-scale modulation of local surface charges
Authors: Hashimoto Tatsuya , Gamo Kentaro , Fukuta Megumi , Zheng Bin , Zettsu Nobuyuki , Yamashita Ichiro , Uraoka Yukiharu , Watanabe Heiji
Published: December 2011

We have systematically investigated the influence of local surface potential distribution on selective adsorption of Ti-binding ferritin (TBF) on SiO2 substrates. We found that the TBF exhibits the adsorption ability onto Ti-decorated SiO2 surface of less than one atomic layer coverage. This experimental finding enabled us to propose a model in which the positively charged sites and their nanometer-scale interval are the dominant factors that determine bond strength between TBF and SiO2 surfaces. Furthermore, on the basis of this model, the adsorption behavior of TBF onto bare SiO2 surfaces was controlled by generation and/or recovery of electrical defects in SiO2.
Ultraviolet/orange bicolor electroluminescence from an n-ZnO/n-GaN isotype heterojunction light emitting diode
Authors: Huang Huihui , Fang Guojia , Li Songzhan , Long Hao , Mo Xiaoming , Wang Haoning , Li Yuan , Jiang Qike , Carroll David L. , Wang Jianbo , Wang Mingjun , Zhao Xingzhong
Published: December 2011

We fabricate an ultraviolet (UV)/orange bicolor light emitting diode (LED) based on an n-ZnO/n-GaN isotype heterojunction, which presents a sharp ultraviolet emission centered at 367 nm and a broad orange emission centered at 640 nm under forward and reverse biases, respectively. Time dependence electroluminescence (EL) measurements reveal that this device shows good stability. The electroluminescence mechanism of the bicolor light emitting diode is discussed in terms of the material properties of the interfacial layer and the luminescence properties of the device in this work.
Measurement of valence band structure in boron-zinc-oxide films by making use of ion beams
Authors: Uhm Han S. , Kwon Gi C. , Choi Eun H.
Published: December 2011

Measurement of valence band structure in the boron-zinc oxide (BZO) films was developed using the secondary electron emission due to the Auger neutralization of ions. The energy distribution profile of the electrons emitted from boron-zinc-oxide films was measured and rescaled so that Auger self-convolution arose; thus, revealing the detailed structure of the valence band and suggesting that a high concentration of boron impurity in BZO films may enhance the transition of electrons and holes through the band gap from the valence to the conduction band in zinc oxide crystals; thereby improving the conductivity of the film.
Communication: Manipulating the singlet-triplet equilibrium in organic biradical materials
Authors: Günaydın-Şen Ö. , Fosso-Tande J. , Chen P. , White J. L. , Allen T. L. , Cherian J. , Tokumoto T. , Lahti P. M. , McGill S. , Harrison R. J. , Musfeldt J. L.
Published: December 2011

We investigated the tunability of the singlet-triplet equilibrium population in the organic biradical 1,4-phenylenedinitrene via magneto-optical spectroscopy. A rich magnetochromic response occurs because applied field increases the concentration of the triplet state species, which has a unique optical signature by comparison with the singlet biradical and the precursor molecule. A Curie-like analysis of the magneto-optical properties allows us to extract the spin gap, which is smaller than previously supposed. These measurements establish the value of local-probe photophysical techniques for magnetic property determination in open-shell systems such as biradicals where a traditional electron paramagnetic resonance Curie law analysis has intrinsic limitations.
Free energy of alternating two-component polymer brushes on cylindrical templates
Authors: Miller William L. , Bozorgui Behnaz , Klymko Katherine , Cacciuto Angelo
Published: December 2011

We use computer simulations to investigate the stability of a two-component polymer brush de-mixing on a curved template into phases of different morphological properties. It has been previously shown via molecular dynamics simulations that immiscible chains having different length and anchored to a cylindrical template will phase separate into stripes of different widths oriented perpendicularly to the cylindrical axis. We calculate free energy differences for a variety of stripe widths, and extract simple relationships between the sizes of the two polymers, N1 and N2, and the free energy dependence on the stripe width. We explain these relationships using simple physical arguments based upon previous theoretical work on the free energy of polymer brushes.
Unique properties of CuZrAl bulk metallic glasses induced by microalloying
Authors: Huang B. , Bai H. Y. , Wang W. H.
Published: December 2011

We studied the glass forming abilities (GFA), mechanical, and physical properties of (CuZr)92.5Al7X0.5 (X = La, Sm, Ce, Gd, Ho, Y, and Co) bulk metallic glasses (BMGs). We find that the GFA, mechanical, and physical properties can be markedly changed and modulated by the minor rare earth addition. The Kondo screening effect is found to exist in (CuZr)92.5Al7Ce0.5 BMG at low temperatures and the Schottky effect exists in all the rare earth element doped BMGs. Our results indicate that the minor addition is an effective way for modulating and getting desirable properties of the BMGs. The mechanisms of the effects of the addition are discussed. The results have implications for the exploration of metallic glasses and for improving the mechanical and low temperature physical properties of BMGs.