bluuebunny/crossref_metadata_2025 huggingface dataset:
Unipolar resistive switching effect in YMn1−δO3 thin films
Authors: Yan Z. B. , Li S. Z. , Wang K. F. , Liu J.-M.
Published: January 2010

Steady unipolar resistive switching of Pt/YMn1−δO3/Pt MIM structure is investigated. High resistance ratio (>104) of high resistance state (HRS) over low resistance state (LRS) and long retention (>105 s) are achieved. It is suggested that the Joule heating and Poole–Frenkel effect dominate respectively the conduction of the LRS and HRS in high electric field region. The resistive switching is explained by the rupture and formation of conductive filaments in association with the local Joule-heat-induced redox inside YMn1−δO3.
Time-resolved photoluminescence spectroscopy of an InGaAs/GaAs quantum well-quantum dots tunnel injection structure
Authors: Syperek M. , Leszczyński P. , Misiewicz J. , Pavelescu E. M. , Gilfert C. , Reithmaier J. P.
Published: January 2010

Low temperature carrier dynamics in the InGaAs/GaAs quantum dot-based tunnel injection structure is studied by the time resolved photoluminescence experiment. We observed strongly modified photoluminescence kinetics between tunnel injection and reference quantum dot structures. Slowing down of the photoluminescence rise time in the tunnel injection system under weak and moderate excitation powers, we attributed to a fingerprint of a feeding process of quantum dot states with nonresonant carriers tunneling from the quantum well reservoir. We propose a simple three-level rate equation model to explain qualitatively the observed photoluminescence temporal behavior. Its result shows a good agreement with our experimental data.
Blinking suppression of single quantum dots in agarose gel
Authors: Ko H. C. , Yuan C. T. , Lin S. H. , Tang Jau
Published: January 2010

Fluorescence blinking is commonly observed in single molecule/particle spectroscopy, but it is an undesirable feature in many applications. We demonstrated that single CdSe/ZnS quantum dots in agarose gel exhibited suppressed blinking behavior. In addition, the long-time exponential bending tail of the power-law blinking statistics was found to be influenced by agarose gel concentration. We suggest that electron transfer from the light state to the dark state might be blocked due to electrostatic surrounding of gel with inherent negatively charged fibers.
Multiple levels in intermediate band solar cells
Authors: Luque Antonio , Linares Pablo G. , Antolín Elisa , Cánovas Enrique , Farmer Corrie D. , Stanley Colin R. , Martí Antonio
Published: January 2010

The presence of multiple energy levels in the intermediate band solar cell (IBSC) is studied by detailed balance calculations under ideal conditions. Multiple levels are found experimentally in IBSCs made with quantum dots (QDs) which act to reduce the limiting efficiency determined from detailed balance calculations. JL-VOC measurements up to 1000 suns on IBSCs are presented together with their fitting to modified detailed balance calculations. It is found that the introduction of the QDs degrades the performance of the host cell but the sub-bandgap cell operates close to ideality.
Assembly of gold nanoparticles of different diameters between nanogap electrodes
Authors: Cheon Donguk , Kumar Sanjeev , Kim Gil-Ho
Published: January 2010

Gold nanoparticles (NPs) of different diameters i.e., 5, 10, and 20 nm, were assembled between 20 nm gap electrodes using ac dielectrophoresis (DEP) process. DEP parameters, such as frequency, trapping time, and voltage of value 1 MHz, 1 s, and 2–3 V, respectively, led to the pearl-chain assembly corresponding to each type of NPs between 20 nm gap electrodes. Mutual DEP could be attributed to the NPs chaining in low field regions and subsequently the DEP force directs these chains to the trapping region. Such controlled assembly of individual NPs may find application in fabricating devices for molecular electronics.
Influence of density on NH bond stretch vibration in plasma enhanced chemical vapor deposited SiNx:H
Authors: Dekkers H. F. W. , Srinivasan Nagendra Babu , Pourtois G.
Published: January 2010

The infrared absorption of hydrogenated silicon nitride (SiNx:H) films provides information about the average configuration of covalent bonds in the film. In plasma enhanced chemical vapor deposited SiNx:H, the absorption spectrum of the NH bonds shows both a systematic shift and a tailing toward lower frequency with the increase in the film density. First-principles computations of NH vibrations show an increased degree of anharmonicity when the H site is weakly interacting with a second neighboring N atom. This interaction becomes more pronounced in films with higher density, which consequently shifts the vibrational spectrum down.
Effect of thermal annealing on the blueshift of energy gap and nitrogen rearrangement in GaAsSbN
Authors: Lin Yan-Ting , Ma Ta-Chun , Lin Hao-Hsiung , Wu Jiun-De , Huang Ying-Sheng
Published: January 2010

We report on the blueshift of energy gap and the nitrogen rearrangement resulting from the thermal treatment of GaAsSbN samples. The composition ranges of N and Sb are from 2% to 3% and from 7% to 11%, respectively. By comparing the photoluminescence peak energy and absorption energy gap, we found that the thermal annealing leads to compositional homogenization. When the annealing temperature is higher than 750 °C, the local vibration mode (LVM) absorbance of isolated substitutional nitrogen NAs starts to increase with the temperature. This finding supports the argument that nitrogen pairs thermally dissociate to isolated nitrogen. In additions, the increase of LVM absorbance accompanies the blueshift of energy gap, suggesting that the blueshift is the consequence of the nitrogen rearrangement. The decomposition of nitrogen pairs has also been observed by photoreflectance spectroscopy (PR). Multiple peaks were resolved from the PR spectra of as-grown GaAsSbN. They are relevant to transitions from regions with different nitrogen pairings and isolated nitrogen. As the annealing temperature increases, the peaks gradually merge to that of isolated nitrogen, indicating the decomposition of nitrogen pairings.
Polarization and charge transfer in the hydration of chloride ions
Authors: Zhao Zhen , Rogers David M. , Beck Thomas L.
Published: January 2010

A theoretical study of the structural and electronic properties of the chloride ion and water molecules in the first hydration shell is presented. The calculations are performed on an ensemble of configurations obtained from molecular dynamics simulations of a single chloride ion in bulk water. The simulations utilize the polarizable AMOEBA force field for trajectory generation and MP2-level calculations are performed to examine the electronic structure properties of the ions and surrounding waters in the external field of more distant waters. The ChelpG method is employed to explore the effective charges and dipoles on the chloride ions and first-shell waters. The quantum theory of atoms in molecules (QTAIM) is further utilized to examine charge transfer from the anion to surrounding water molecules. The clusters extracted from the AMOEBA simulations exhibit high probabilities of anisotropic solvation for chloride ions in bulk water. From the QTAIM analysis, 0.2 elementary charges are transferred from the ion to the first-shell water molecules. The default AMOEBA model overestimates the average dipole moment magnitude of the ion compared to the quantum mechanical value. The average magnitude of the dipole moment of the water molecules in the first shell treated at the MP2-level, with the more distant waters handled with an AMOEBA effective charge model, is 2.67 D. This value is close to the AMOEBA result for first-shell waters (2.72 D) and is slightly reduced from the bulk AMOEBA value (2.78 D). The magnitude of the dipole moment of the water molecules in the first solvation shell is most strongly affected by the local water-water interactions and hydrogen bonds with the second solvation shell, rather than by interactions with the ion.
Monte Carlo study of carrier-light coupling in terahertz quantum cascade lasers
Authors: Jirauschek Christian
Published: January 2010

We present a method for self-consistently including the optical cavity field into Monte Carlo-based carrier transport simulations. This approach allows for an analysis of the actual lasing operation in quantum cascade lasers, considering effects such as gain, saturation, and longitudinal mode competition. Simulation results for a terahertz quantum cascade laser are found to be consistent with experiment.
The role of La surface chemistry in the passivation of Ge
Authors: Dimoulas A. , Tsoutsou D. , Panayiotatos Y. , Sotiropoulos A. , Mavrou G. , Galata S. F. , Golias E.
Published: January 2010

The oxidation of a Ge surface by molecular oxygen in the presence of ultrathin La, Al, and Hf layers was examined by in situ x-ray photoelectron spectroscopy. Upon exposure to O2, clean bare Ge and Hf-covered or Al-covered Ge surfaces show no Ge–O bond formation. On the contrary, a La-covered Ge surface strongly reacts with O2 forming a stable germanate LaGeOx compound. This has a beneficial side effect for the interface because the formation of volatile GeO is suppressed, resulting in the good passivating properties of LaGeOx. The photoemission results are correlated with the oxygen density differences in the corresponding oxides.
The Impact of Urbanization on Current and Future Coastal Precipitation: A Case Study for Houston
Authors: Shepherd J Marshall , Carter Michael , Manyin Michael , Messen Dmitry , Burian Steve
Published: January 2010

The approach of this study was to determine, theoretically, what impact current and future urban land use in the coastal city of Houston, Texas has on the space and time evolution of precipitation on a ‘typical’ summer day. Regional model simulations of a case study for 25 July 2001 were applied to investigate possible effects of urban land cover on precipitation development. Simulations in which Houston urban land cover was included resolved rain cells associated with the sea breeze front and a possible urban circulation on the northwest fringe of the city. Simulations without urban land cover did not capture the initiation and full intensity of the ‘hypothesized’ urban-induced rain cell. The response is given the terminology the ‘urban rainfall effect’ or URE. An urban growth model (UrbanSim) was used to project the urban land-cover growth of Houston, Texas from 1992 to 2025. A regional atmospheric-land surface model was then run with the 2025 urban land-cover scenario. Though we used a somewhat theoretical treatment, our results show the sensitivity of the atmosphere to urban land cover and illustrate how atmosphere — land interactions can affect cloud and precipitation processes. Two urban-induced features, convergence zones along the inner fringe of the city and an urban low-pressure perturbation, appear to be important factors that lead to enhanced rain clouds independently or in conjunction with the sea breeze. Simulations without the city (NOURBAN) produced less cumulative rainfall in the west-northwest Houston area than simulations with the city represented (URBAN). Future urban land-cover growth projected by UrbanSim (URBAN2025) led to a more expansive area of rainfall, owing to the extended urban boundary and increased secondary outflow activity. This suggests that the future urban land cover might lead to temporal and spatial precipitation variability in coastal urban microclimates. It was beyond the scope of the analysis to conduct an extensive sensitivity analysis of cause — effect relationships, though the experiments provide some clues as to why the rainfall evolution differs. This research demonstrates a novel application of urban planning and weather — climate models. It also raises viable questions concerning future planning strategies in urban environments in consideration of hydroclimate changes.
Sustainable Neighbourhood Development: Missed Opportunities in Southern California
Authors: Garde Ajay , Saphores Jean-Daniel , Matthew Richard , Day Kristen
Published: January 2010

We examine the diffusion of sustainable planning and design concepts into neighbourhood development projects, based on findings of a survey of planners in all 180 cities of five Southern California counties. Sustainable neighbourhood development has particular significance in Southern California owing to the regions's rapid growth. We compare ‘typical’ and ‘innovative’ neighbourhood developments to determine whether sustainable planning and design concepts are being incorporated in these projects. Although planners agree that ‘innovative’ projects are more likely than ‘typical’ projects to incorporate sustainable planning and design concepts, sustainability is not a high priority even in innovative neighbourhood projects. Our respondents identified significant barriers to and limited opportunities for encouraging sustainable neighbourhood development. These trends in planning and design appear likely to continue unless strong policy and other mechanisms are adopted to encourage sustainable neighbourhood development. The paper concludes with recommendations to promote more sustainable neighbourhood development.
Measuring the Breathing Light Illusion by Means of Induced Simultaneous Contrast
Authors: Gori Simone , Giora Enrico , Agostini Tiziano
Published: January 2010

By blurring the margins of a surface, both its brightness and the perceived contrast against a superimposed figure with sharp boundaries increase. Also, if one approaches a blurred white spot on a grey background, this spot will appear wider and brighter: this phenomenon is known as the Breathing Light Illusion (BLI) (Gori and Stubbs, 2006 Perception35 1573–1577). We studied the increment of the achromatic contrast of a grey sharp-boundary disk when it was superimposed on the BLI. This augmentation of the perceived contrast in the dynamic presentation of the BLI was significantly stronger than the effect that Agostini and Galmonte (2002a Psychonomic Bulletin and Review9 264–269) obtained in static presentation. Our study leads to an indirect quantification of the BLI. Two control experiments showed that the increment of the achromatic contrast depends on the blurred spot and is independent of the dynamic increment in angular size. These results argue for a causal relationship between the increase in brightness due to the BLI and the darkening of the superimposed disk.
Blueprint for antimicrobial hit discovery targeting metabolic networks
Authors: Shen Y. , Liu J. , Estiu G. , Isin B. , Ahn Y-Y. , Lee D-S. , Barabási A-L. , Kapatral V. , Wiest O. , Oltvai Z. N.
Published: January 2010

Advances in genome analysis, network biology, and computational chemistry have the potential to revolutionize drug discovery by combining system-level identification of drug targets with the atomistic modeling of small molecules capable of modulating their activity. To demonstrate the effectiveness of such a discovery pipeline, we deduced common antibiotic targets in
Escherichia coli
and
Staphylococcus aureus
by identifying shared tissue-specific or uniformly essential metabolic reactions in their metabolic networks. We then predicted through virtual screening dozens of potential inhibitors for several enzymes of these reactions and showed experimentally that a subset of these inhibited both enzyme activities in vitro and bacterial cell viability. This blueprint is applicable for any sequenced organism with high-quality metabolic reconstruction and suggests a general strategy for strain-specific antiinfective therapy.
Establishment of a neuroepithelial barrier by Claudin5a is essential for zebrafish brain ventricular lumen expansion
Authors: Zhang Jingjing , Piontek Jörg , Wolburg Hartwig , Piehl Christian , Liss Martin , Otten Cécile , Christ Annabel , Willnow Thomas E. , Blasig Ingolf E. , Abdelilah-Seyfried Salim
Published: January 2010

Lumen expansion driven by hydrostatic pressure occurs during many morphogenetic processes. Although it is well established that members of the Claudin family of transmembrane tight junction proteins determine paracellular tightness within epithelial/endothelial barrier systems, functional evidence for their role in the morphogenesis of lumenized organs has been scarce. Here, we identify Claudin5a as a core component of an early cerebral-ventricular barrier system that is required for ventricular lumen expansion in the zebrafish embryonic brain before the establishment of the embryonic blood–brain barrier. Loss of Claudin5a or expression of a tight junction-opening Claudin5a mutant reduces brain ventricular volume expansion without disrupting the polarized organization of the neuroepithelium. Perfusion experiments with the electron-dense small molecule lanthanum nitrate reveal that paracellular tightness of the cerebral-ventricular barrier decreases upon loss of Claudin5a. Genetic analyses show that the apical neuroepithelial localization of Claudin5a depends on epithelial cell polarity and provide evidence for concerted activities between Claudin5a and Na
+
,K
+
-ATPase during luminal expansion of brain ventricles. These data establish an essential role of a barrier-forming Claudin in ventricular lumen expansion, thereby contributing to brain morphogenesis.
Costly Cell Phones: The Impact of Cell Phone Rings on Academic Performance
Authors: End Christian M. , Worthman Shaye , Mathews Mary Bridget , Wetterau Katharina
Published: January 2010

College students participated in a study on the “psychology of note taking” during which they took notes on video content and later completed a multiple-choice test on the material. Researchers assigned 71 participants to either the ringing condition (the video was disrupted by a ringing cell phone) or the control condition (no cell phone rings disrupted the video). The hypothesis that the cell phone rings would impair performance was confirmed. Compared to the control group, participants in the ringing condition performed significantly worse on the disrupted test items and were less likely to include the disrupted information in their notes. Citing empirical evidence of academic impairment in course syllabi may improve regulation of cell phone use in the classroom.
Teaching with Purpose: An Interview with Thomas E. Ludwig
Authors: Ludwig Timothy D. , Ludwig David J.
Published: January 2010

Thomas E. Ludwig is the John Dirk Werkman Professor of Psychology at Hope College, where he joined the faculty in 1977 after receiving his PhD in development and aging from Washington University in St. Louis. His research focuses on developmental issues in cognitive neuropsychology. He is also the author or coauthor of more than a dozen sets of instructional computer activities, including PsychSim, PsychQuest, PsychOnline, PsychInquiry, Exploring Human Development, ActivePsych, and Concepts in Action. In 2003, Hope College presented him with its Provost's Award for Excellence in Teaching, and in 2005, the American Psychological Foundation honored him with the Charles L. Brewer Distinguished Teaching of Psychology Award.

Timothy D. Ludwig received an MA from Wake Forest University and a PhD in industrial/organizational psychology from Virginia Tech. Since 1994, he has been on faculty at Appalachian State University where he has received the University Deans Distinguished Graduate Faculty Award and the UNC Board of Governors Award for Excellence in Teaching. He is currently the editor of the Journal of Organizational Behavior Management and serves on the board of the Organizational Behavior Management National Network. He is the author of dozens of scholarly articles and one book that empirically document the successes of behavioral methods to improve safety and quality in industry.

David J. Ludwig is emeritus professor of psychology at Lenoir-Rhyne University. He received an MDiv from Concordia Seminary, in St. Louis, and a PhD in personality from Washington University in St. Louis. His creative blending of psychology and religion has spanned more than 40 years as a university professor, a licensed psychologist, and a Lutheran minister. During this time, he has authored seven books, several DVD series, and numerous professional articles, while speaking internationally on practical ways to develop healthier personal and family relationships.
A Video Introduction to Psychology: Enhancing Research Interest and Participation
Authors: Sacco Donald F. , Bernstein Michael J.
Published: January 2010

To assess the extent to which a video about psychological research would heighten introductory psychology students' interest and participation in research studies, we created a video about ongoing research at our university, the value of research participation, and course requirements for the research experience. Instructors in 4 courses (N = 471 students) verbally explained the research requirement and distributed a document detailing alternatives for completing it. In 2 of these courses, students also saw the video. Results indicated that students who viewed the video reported greater interest in research and completed more research participation hours than did students who did not view the video. We discuss the potential advantages of standardized, noncoercive procedures to encourage student participation in research.
Differentiating Psychology Students' Perceptions of Teachers Using the Teacher Behavior Checklist
Authors: Keeley Jared , Furr R. Michael , Buskist William
Published: January 2010

Keeley, Smith, and Buskist (2006) investigated the psychometric properties of the Teacher Behavior Checklist (TBC), but did not provide evidence that the measure could differentiate among teachers. This study required students at 2 schools to rate their best professor, worst professor, and most recent professor on the TBC. We found highly similar results across these schools. Differences among teachers accounted for more variability in TBC ratings than other possible sources. TBC ratings evidenced significant differences across good versus bad teachers.
Limited Access: The Status of Disability in Introductory Psychology Textbooks
Authors: Goldstein Susan B. , Siegel Dustin , Seaman Jessica
Published: January 2010

We content analyzed 24 best-selling introductory psychology textbooks to assess the presence and nature of material addressing issues of disability. Content analyses assessed the frequency with which specific impairments are presented, the chapters and topics most likely to contain disability-related material, the context in which people with disabilities are portrayed, and the type of language used to discuss disability. Results indicated that material on disability in introductory textbooks continues to be limited and portrays people with disabilities in a stereotypical manner. Recommendations are presented for improving the integration of disability into introductory psychology textbooks.
Cross-mapping and the identification of editing sites in mature microRNAs in high-throughput sequencing libraries
Authors: de Hoon Michiel J.L. , Taft Ryan J. , Hashimoto Takehiro , Kanamori-Katayama Mutsumi , Kawaji Hideya , Kawano Mitsuoki , Kishima Mami , Lassmann Timo , Faulkner Geoffrey J. , Mattick John S. , Daub Carsten O. , Carninci Piero , Kawai Jun , Suzuki Harukazu , Hayashizaki Yoshihide
Published: January 2010

MicroRNAs (miRNAs) are short (20–23 nt) RNAs that are sequence-specific mediators of transcriptional and post-transcriptional regulation of gene expression. Modern high-throughput technologies enable deep sequencing of such RNA species on an unprecedented scale. We find that the analysis of small RNA deep-sequencing libraries can be affected by cross-mapping, in which RNA sequences originating from one locus are inadvertently mapped to another. Similar to cross-hybridization on microarrays, cross-mapping is prevalent among miRNAs, as they tend to occur in families, are similar or derived from repeat or structural RNAs, or are post-transcriptionally modified. Here, we develop a strategy to correct for cross-mapping, and apply it to the analysis of RNA editing in mature miRNAs. In contrast to previous reports, our analysis suggests that RNA editing in mature miRNAs is rare in animals.
Manchester’s John Rylands Library
Authors: Glasgow Eric
Published: January 2010

The circumstances surrounding the foundation of the John Rylands Library, and the commercial and cultural context within which it was established are discussed. The background of John Rylands himself, and of his book collecting, is considered. The general nature of the collections at the Library’s opening is outlined. The relevance of the Library in modern times, and its secured future as part of the University of Manchester, is discussed.
Opinion paper: Is national planning for acquisitions and document supply still valid?
Authors: Line Maurice B.
Published: January 2010

The time when every country needed to plan its own acquisitions and document supply system may be over. For purposes of consultation, it is most convenient for users to have wanted items that are not available locally in one large collection, though this runs into political and other difficulties. Co‐operative acquisition systems rarely work. Remote consultation of digitised material would change this situation. It is now usually as fast to obtain “copiable” items from foreign countries as from one’s own, even when they have to be supplied by paper copies; and more and more items are accessible on the Internet. For books, the time taken to supply and the cost still vary considerably between domestic and other sources; there is no easy solution unless and until large amounts of material are digitised, and then remote supply and remote consultation begin to merge. As a result of the various factors, there is now no need for national acquisition and supply policies.
The influence of procedure on rent determination in the commercial property market of England and Wales
Authors: Crosby Neil , Murdoch Sandi
Published: January 2010

This paper examines the effect which the rent assessment process has on the level of rents and rental values in the commercial property market in England and Wales, by asking: is there an accepted definition of open market rental value which is consistently adhered to, irrespective of the context in which the rent is assessed? How, in theory, do the procedures by which an assessment of open market rental value is arrived at differ as between a new letting, a lease renewal, and a rent review? Is there any evidence to suggest that any theoretical differences in the operation of the various rent assessment procedures are borne out in practice? In particular, is there any evidence that in new lettings and lease renewals lease terms are changed after the rent has been finalised? Is there any evidence to demonstrate that there are different levels of rent which are sufficiently consistent to be referable to the context in which the rent was assessed? If so, does this produce difficulties in the valuation process which may not be presently fully appreciated? In addition to a review of the relevant literature, the primary research undertaken for the study was a survey of surveyors and solicitors involved in commercial lettings and rent reviews and the compilation of a database of rental valuations and transactions.
Decision making in small property companies
Authors: Gallimore Paul , Hansz J. Andrew , Gray Adelaide
Published: January 2010

The literature on investor decision‐making behaviour in property investment is sparse, loosely integrated and focused principally upon large, institutional investors. It reflects rational, normative models that treat investor behaviour as highly structured and formalised. By contrast, behavioural psychology suggests that individuals frequently act sub‐optimally. These ideas have been explored in financial decision making and have been found in the actions of property valuers and property lenders. This paper addresses this neglected area of property investment decision‐making. Semi‐structured interviews were conducted with a sample of property investment directors of smaller property companies. The interviews investigate the decision‐making structures in these companies, the process by which investment strategy is formulated, the investment “screening” process and the determinants of purchase/sell decisions. The findings are discussed and related to the literature on decision making under uncertainty.
Exploring spirituality among youth in foster care: findings from the Casey Field Office Mental Health Study
Authors: Jackson Lovie J. , White Catherine Roller , O'Brien Kirk , DiLorenzo Paul , Cathcart Ernie , Wolf Mary , Bruskas Delilah , Pecora Peter J. , Nix‐Early Vivian , Cabrera Jorge
Published: January 2010

This study examined spiritual coping mechanisms, beliefs about spirituality and participation in spiritual activities and in other positive activities among adolescents in foster care. A multidimensional measure of spirituality was developed for face‐to‐face interviews with 188 youth (ages 14–17) from diverse racial/ethnic backgrounds in the United States. Findings revealed 95% of youth believe in God, over 70% believe God is ‘creator’ and God is ‘love’, and 79% considered prayer a spiritual practice. Most youth said love and forgiveness help them heal. Two‐thirds (67%) reported responding to ‘bad or tragic things happening’ by spending time alone, and over half responded by praying (59%) or sharing the problem with someone else (56%). Youth's top three spiritual goals were to follow God's plan for them, become a better person, and know their purpose in life. Based on the value youth ascribed to spiritual coping mechanisms, recommendations for policy and practice focus on the integration of spirituality into practice and caregiving for youth in foster care.
Young people leaving care in Sweden
Authors: Höjer Ingrid , Sjöblom Yvonne
Published: January 2010

The transition from a placement in care to an independent life can be a problematic phase for young people. In Sweden, special care‐leaving services are almost non‐existent. What then happens to young people when they leave a placement in out‐of‐home care? This paper draws on the results of a study in which 16 young care leavers between the ages of 18 and 22 years were interviewed. Telephone interviews were also performed with the young care leavers' parents, social workers, foster carers and institutional staff. The aim of the study was to investigate how young care leavers perceive the transition from care to an independent life. The Swedish welfare model, the prolonged transition to adulthood and the family‐oriented welfare discourse have been used as analytical perspectives. The results show that young care leavers have a pronounced need for social, emotional, practical and financial support. Whilst such support is occasionally provided by foster carers and residential staff, it is seldom given by social services or biological parents. This group is at risk of facing severe problems in the transitional phase from care to independent life, a fact that is not acknowledged by the Swedish welfare system.
Caffeic acid phenethyl ester inhibits nuclear factor-κB and protein kinase B signalling pathways and induces caspase-3 expression in primary human CD4+ T cells
Authors: Wang L-C , Chu K-H , Liang Y-C , Lin Y-L , Chiang B-L
Published: January 2010

Caffeic acid phenethyl ester (CAPE), an active component in propolis, is known to have anti-tumour, anti-inflammatory and anti-oxidant properties. In this study, the effects of CAPE on the functions of primary human CD4+ T cells were evaluated in vitro. CAPE significantly suppressed interferon (IFN)-γ and interleukin (IL)-5 production and proliferation of CD4+ T cells stimulated by soluble anti-CD3 and anti-CD28 monoclonal antibodies in both healthy subjects and asthmatic patients. CAPE inhibited nuclear factor (NF)-κB activation and protein kinase B (Akt) phosphorylation, but not p38 mitogen-activated protein kinase (MAPK) phosphorylation in T cells. CAPE also induced active caspase-3 expression in CD4+ T cells; CCR4+CD4+ T cells were more sensitive to CAPE induction than CXCR3+CD4+ T cells. Together, these results indicate that CAPE inhibits cytokine production and proliferation of T cells, which might be related to the NF-κB and Akt signalling pathways, and that CCR4+CD4+ T cells are more sensitive to CAPE inhibition. This study provides a new insight into the mechanisms of CAPE for immune regulation and a rationale for the use of propolis for the treatment of allergic disorders.
High-density lipoprotein affects antigen presentation by interfering with lipid raft: a promising anti-atherogenic strategy
Authors: Wang S-H , Yuan S-G , Peng D-Q , Zhao S-P
Published: January 2010

Atherosclerosis is a chronic inflammatory disease. Immunomodulation of atherosclerosis emerges as a promising approach to prevention and treatment of this widely prevalent disease. The function of high-density lipoprotein (HDL) to promote reverse cholesterol transport may explain the ability of its protection against atherosclerosis. Findings that HDL and apolipoprotein A-I (apoA-I) inhibited the ability of antigen presenting cells (APCs) to stimulate T cells might be attributed to lipid raft, a cholesterol-rich microdomain exhibiting functional properties depending largely upon its lipid composition. Thus, modulating cholesterol in lipid raft may provide a promising anti-atherogenic strategy.
Prevention and treatment of experimental autoimmune encephalomyelitis with clonotypic CDR3 peptides: CD4+ FoxP3+ T‐regulatory cells suppress interleukin‐2‐dependent expansion of myelin basic protein‐specific T cells
Authors: Buenafe Abigail C. , Andrew Shayne , Afentoulis Michael , Offner Halina , Vandenbark Arthur A.
Published: January 2010

T‐cell receptor (TCR)‐derived peptides are recognized by the immune system and are capable of modulating autoimmune responses. Using the myelin basic protein (MBP) TCR 1501 transgenic mouse model, we demonstrated that TCR CDR3 peptides from the transgenic TCR can provide a protective effect when therapy is initiated before the induction of experimental autoimmune encephalomyelitis (EAE). More importantly, TCR CDR3 peptide therapy can ameliorate the disease when administered after EAE onset. Concurrent with the therapeutic effects, we observed reduced T‐cell proliferation and reduced interleukin‐2 (IL‐2) levels in response to stimulation with MBP‐85‐99 peptide in splenocyte cultures from mice receiving TCR CDR3 peptides compared with that of control mice. Moreover, we found that Foxp3+ CD4 T cells from mice protected with TCR CDR3 peptide are preferentially expanded in the presence of IL‐2. This is supportive of a proposed mechanism where Foxp3+ T‐regulatory cells induced by therapy with MBP‐85‐99 TCR CDR3 peptides limit expansion and the encephalitogenic activity of MBP‐85‐99‐specific T cells by regulating the levels of secreted IL‐2.
Analysis of channel shapes in track membranes by scanning electron microscopy
Authors: ORELOVICH O.L. , SARTOWSKA B.A. , PRESZ A. , APEL P. YU.
Published: January 2010

Control over pore geometry opens the way to a number of new applications of track‐etch membranes (TMs). A special method of etching was developed to produce TMs with non‐cylindrical pore profile. The direct observation of channel shape on fractures of track membranes was performed with a scanning electron microscope (SEM). The SEM images of the surface and cross‐section of TMs with different pore morphology are shown. The channel diameter as a function of the depth below surface was measured and quantitative analysis was realized.
Asymmetry of the two‐beam geometry in EMCD experiments
Authors: RUSZ J. , OPPENEER P.M. , LIDBAUM H. , RUBINO S. , LEIFER K.
Published: January 2010

We analyse theoretically the influence of the asymmetry of the two‐beam geometry on quantitative measurements of the energy‐loss magnetic chiral dichroism. Our simulations indicate that this asymmetry is not very strong inside or close to the Thales circle, but in other regions of the diffraction plane it can hinder an accurate extraction of the orbital to spin moment ratio.
Mechanical alloying and high pressure processing of a TiAl‐V intermetallic alloy
Authors: DYMEK S. , WRÓBEL M. , WITCZAK Z. , BLICHARSKI M.
Published: January 2010

An alloy with a chemical composition of Ti‐45Al‐5V (at.%) was synthesized by mechanical alloying in a Szegvari‐type attritor from elemental powders of high purity. Before compaction, the powders were characterized by X‐ray diffraction and scanning as well as transmission electron microscopy. The compaction of powders was carried out by hot isostatic pressing and hot isostatic extrusion. The resulting material was subjected to microstructural and mechanical characterization. The microstructure investigated by transmission and scanning electron microscopy supplemented by X‐ray diffraction revealed that the bulk material was composed of a mixture of TiAl‐ and Ti3Al‐based phases, however, the typical lamellar microstructure for such alloys was not observed. The materials exhibited exceptionally high yield strength together with satisfactory ductility and fracture toughness. The high strength was unequivocally due to grain refinement and the presence of oxide dispersoid.
Transmission electron microscopy study of Ar‐filled bubbles in steel
Authors: KLIMENKOV M. , LINDAU R. , MÖSLANG A.
Published: January 2010

Ar‐filled bubbles in an oxide‐dispersion‐strengthened (ODS) alloy were characterized by analytical transmission electron microscopy. Energy dispersive X‐ray analysis combined with nanoscale imaging was employed for quantitative analysis of Ar gas locked in a bubble 6 nm in size. As the Ar bubbles are formed at the ODS particles – matrix interface, the known Ti2Y2O7 composition and size of ODS particles served as a reference in quantification of the Ar signal and for the calculation of the bubble size and the Ar density inside. The Ar pressure was also calculated by modified Van der Waals equation.
Quantitative analysis and modelling of hepatic iron stores using stereology and spatial statistics
Authors: GHUGRE N.R. , GONZALEZ‐GOMEZ I. , SHIMADA H. , COATES T.D. , WOOD J.C.
Published: January 2010

Hepatic iron overload is a common clinical problem resulting from hyperabsorption syndromes and from chronic transfusion therapy. Not only does iron loading vary between reticuloendothelial stores and hepatocytes, but iron is heterogeneously distributed within hepatocytes as well. Since the accessibility of iron particles to chelation may depend, in part, on their distribution, we sought to characterize the shape and scale of iron deposition in humans with transfusional iron overload. Toward this end, we performed a histological analysis of iron stores in liver biopsy specimens of 20 patients (1.3–57.8 mg iron/g dry tissue weight) with aid of electron and light microscopy. We estimated distributions related to variability in siderosomal size, proximity of iron centres and inter‐cellular iron loading. These distributions could be well modelled by Gamma distribution functions over most of the pathologic range of iron concentrations. Thus, for a given liver iron burden, a virtual iron‐overloaded liver could be created that served as a model for the true histologic appearance. Such a model may be helpful for understanding the mechanics of iron loading or in predicting response to iron removal therapy.
Evaluation of different methods for the characterization of carrot resistance to the alternaria leaf blight pathogen (Alternaria dauci) revealed two qualitatively different resistances
Authors: Boedo C. , Berruyer R. , Lecomte M. , Bersihand S. , Briard M. , Le Clerc V. , Simoneau P. , Poupard P.
Published: January 2010

Alternaria leaf blight (ALB), caused by Alternaria dauci, is one of the most damaging foliar diseases of carrot worldwide. The aim of this study was to compare different methods for evaluating levels of carrot resistance to ALB. Three techniques were investigated by comparison with a visual disease assessment control: in vivo conidial germination, a bioassay based on a drop‐inoculation method, and in planta quantification of fungal biomass by quantitative PCR (Q‐PCR). Three carrot cultivars showing different degrees of resistance to A. dauci were used, i.e. a susceptible cultivar (Presto) and two partially resistant genotypes (Texto and Bolero), challenged with an aggressive or a very aggressive isolate of A. dauci. Both partially resistant genotypes produced a higher mean number of germ tubes per conidium (up to 3·42±0·35) than the susceptible one (1·26±0·18). The drop‐inoculation results allowed one of the partially resistant genotypes (Bolero, log10(S+1) = 1·34±0·13) to be distinguished from the susceptible one (1·90±0·13). By contrast, fungal growth measured by Q‐PCR clearly differentiated the two partially resistant genotypes with log10(I) values of 2·77±0·13 compared to the susceptible cultivar (3·65±0·13) at 15 days post‐inoculation. This result was strongly correlated (r2 = 0·91) with the disease severity index scored at the same date. Data obtained with the different assessment methods strongly suggest that the Texto and Bolero genotypes have different genetic resistance sources.
Risk‐reducing mastectomy and salpingo‐oophorectomy in unaffected BRCA mutation carriers: uptake and timing*
Authors: Skytte A‐B , Gerdes A‐M , Andersen MK , Sunde L , Brøndum‐Nielsen K , Waldstrøm M , Kølvraa S , Crüger D
Published: January 2010

Skytte A‐B, Gerdes A‐M, Andersen MK, Sunde L, Brøndum‐Nielsen K, Waldstrøm M, Kølvraa S, Crüger D. Risk‐reducing mastectomy and salpingo‐oophorectomy in unaffected BRCA mutation carriers: uptake and timing.

Once female carriers of a BRCA mutation are identified they have to make decisions on risk management. The aim of this study is to outline the uptake of risk‐reducing surgery in the Danish population of BRCA mutation positive women and to search for factors affecting this decision. We analysed data from 306 healthy BRCA carriers with no personal history of ovarian or breast cancer. We found a 10‐year uptake of 75% for risk‐reducing salpingo‐oophorectomy and 50% for risk‐reducing mastectomy by time to event analysis. Age and childbirth influenced this decision. The uptake rate has not changed significantly over the last decade. Risk‐reducing surgeries are widely acceptable among Danish BRCA mutation positive women and the uptake of prophylactic mastectomy is higher than in most other countries.
Clinical and molecular aspects of aniridia
Authors: Kokotas H , Petersen MB
Published: January 2010

Kokotas H, Petersen MB. Clinical and molecular aspects of aniridia.

Aniridia is a severe, congenital ocular malformation inherited in an autosomal‐dominant fashion with high penetrance and variable expression. Eye morphogenesis in humans involves a molecular genetic cascade in which a number of developmental genes interact in a highly organized process during the embryonic period to produce functional ocular structures. Among these genes, paired box gene 6 (PAX6) has an essential role as it encodes a phylogenetically conserved transcription factor almost universally employed for eye formation in animals with bilateral symmetry, despite widely different embryological origins. To direct eye development, PAX6 regulates the tissue‐specific expression of diverse molecules, hormones, and structural proteins. In humans, PAX6 is located in chromosome 11p13, and its mutations lead to a variety of hereditary ocular malformations of the anterior and posterior segment, among which aniridia and most probably foveal hypoplasia are the major signs. Aniridia occurs due to decreased dosage of the PAX6 gene and exists in both sporadic and familial forms. The mutations are scattered throughout the gene and the vast majority of those reported so far are nonsense mutations, frameshift mutations, or splicing errors that are predicted to cause pre‐mature truncation of the PAX6 protein, causing haploinsufficiency. Here we review the data regarding the mechanisms and the mutations that relate to aniridia.
Suspected allergy to local anaesthetics: follow‐up in 135 cases
Authors: HARBOE T. , GUTTORMSEN A. B. , AAREBROT S. , DYBENDAL T. , IRGENS Å. , FLORVAAG E.
Published: January 2010

Background: Local anaesthetics (LA) are generally considered safe with respect to allergy. However, various clinical reactions steadily occur. Even though most reactions are manifestations of reflexes to perceptive stimuli, uncertainty often remains regarding a possible allergic mechanism. This uncertainty later leads to an avoidance of local anaesthesia and unnecessarily painful interventions, resource‐consuming general anaesthesia or even the risk of re‐exposure to other yet unidentified allergens. In the present study, follow‐up procedures at an allergy clinic were analysed to examine the frequency of identified causative agents and pathogenetic mechanisms and evaluate the strength of the diagnostic conclusions.

Method: The medical records of 135 cases with alleged allergic reactions to LA were reviewed. Diagnoses were based on case histories, skin tests, subcutaneous challenge tests and in vitro IgE analyses.

Results: Two events (1.5%) were diagnosed as hypersensitivity to LA, articaine–adrenaline and tetracaine–adrenaline, respectively. Ten reactions (7%) were diagnosed as IgE‐mediated allergy to other substances including chlorhexidine, latex, triamcinolone and possibly hexaminolevulinate. As challenge testing was not consistently performed with the culprit LA compound, follow‐ups were short of definitely refuting hypersensitivity in 61% of the cases. The reported clinical manifestations were in general diagnostically unspecific, but itch and generalised urticaria were most frequent in test‐positive cases.

Conclusion: Reactions during local anaesthesia are rarely found to be an IgE‐mediated LA allergy. Whenever the clinical picture is compatible with allergy, other allergens should also be tested.
Effect of Population Density and Female Body Size on Number and Size of Offspring in a Species with Size‐Dependent Contests over Resources
Authors: Rauter Claudia M. , Mcguire Michael J. , Gwartney Melissa M. , Space Jason E.
Published: January 2010

When size‐dependent contests over resources influence reproductive success, the trade‐off between number and size of offspring depends on the frequency of contests. Under these circumstances, clutch size should decrease and offspring size should increase as contests become more frequent. We tested these predictions with the burying beetleNicrophorus pustulatusthrough manipulation of rearing densities. Burying beetles reproduce on small vertebrate carcasses, a rare but high quality food source for the larvae. Large beetles are more likely to win contests over carcasses and gain exclusive access to a carcass. The winner of a contest kills eggs and larvae already present on a carcass. As a result of the rarity of carcasses, burying beetles are unlikely to breed more than once. As predicted, brood size ofN. pustulatusdecreased with increasing rearing density. Despite a negative correlation between brood size and larval mass, larval mass did not increase with increasing rearing density. This may be due to the special biology ofN. pustulatuswhich can use snake eggs for reproduction. Potentially larger supply of resources and generally small population densities ofN. pustulatusmay weaken selection on body size and thus the correlation between brood size and larval mass. As size‐dependent constraints can limit reproductive phenotypes, we examined whether female size influenced reproductive phenotype. Small females produced larger broods with smaller, but more variable, offspring than large females. Mechanical constraints of egg size seem an unlikely explanation for the differences because burying beetles can compensate for small egg size through parental care. Energetic constraints may impact small females because body mass and brood size of small females decreased with increasing density. Yet, at all density levels small females produced larger, not smaller, broods than large females. The larger and more variable broods of small females seem to be in agreement with a bet‐hedging strategy.