bluuebunny/crossref_metadata_2025 huggingface dataset:
Structural, electrical, thermal and optical properties of the nonlinear optical crystal L‐Arginine Fluoride
Authors: Mohandoss R. , Dhanuskodi S. , Jayalakshmy M. S. , Philip J. , Bhagavannarayana G.
Published: April 2012

Single crystals of L‐Arginine Fluoride (LAF) have been grown by the slow evaporation technique, and the crystalline perfection was studied by HRXRD. Optical absorption studies reveal the lower cut off wavelength (280 nm) and the band gap (5.1 eV). The dielectric constant and dielectric loss have been measured as a function of frequency (42 Hz–5 MHz) and temperature (307‐368K) and the activation energy is 77 μeV. The thermal transport properties such as thermal conductivity (0.88 ± 0.02 W/mK) and specific heat capacity (482±24 J/kg/K) have been estimated by the photopyroelectric technique. The nonlinear refractive index n2, is found to be of the order of 10−13 cm2/W by the Z‐scan technique.
A myelin gene causative of a catatonia‐depression syndrome upon aging
Authors: Hagemeyer Nora , Goebbels Sandra , Papiol Sergi , Kästner Anne , Hofer Sabine , Begemann Martin , Gerwig Ulrike C. , Boretius Susann , Wieser Georg L. , Ronnenberg Anja , Gurvich Artem , Heckers Stephan H. , Frahm Jens , Nave Klaus‐Armin , Ehrenreich Hannelore
Published: April 2012

Severe mental illnesses have been linked to white matter abnormalities, documented by postmortem studies. However, cause and effect have remained difficult to distinguish. CNP (2′,3′‐cyclic nucleotide 3′‐phosphodiesterase) is among the oligodendrocyte/myelin‐associated genes most robustly reduced on mRNA and protein level in brains of schizophrenic, bipolar or major depressive patients. This suggests that CNP reduction might be critical for a more general disease process and not restricted to a single diagnostic category. We show here that reduced expression of CNP is the primary cause of a distinct behavioural phenotype, seen only upon aging as an additional ‘pro‐inflammatory hit’. This phenotype is strikingly similar in Cnp heterozygous mice and patients with mental disease carrying the AA genotype at CNP SNP rs2070106. The characteristic features in both species with their partial CNP ‘loss‐of‐function’ genotype are best described as ‘catatonia‐depression’ syndrome. As a consequence of perturbed CNP expression, mice show secondary low‐grade inflammation/neurodegeneration. Analogously, in man, diffusion tensor imaging points to axonal loss in the frontal corpus callosum. To conclude, subtle white matter abnormalities inducing neurodegenerative changes can cause/amplify psychiatric diseases.
State of the art of the bioliq® process for synthetic biofuels production
Authors: Dahmen Nicolaus , Dinjus Eckhard , Kolb Thomas , Arnold Ulrich , Leibold Hans , Stahl Ralph
Published: April 2012

Synthetic fuels from biomass (also referred to as BTL, biomass to liquids) may contribute to the future motor fuel consumption to a considerable extent. To overcome the logistical hurdles connected with the industrial use of large quantities of biomass, the de‐central‐centralized bioliq® concept has been developed. It is based on a regional pretreatment of biomass for energy densification by fast pyrolysis. The intermediate referred to as biosyncrude allows for economic long‐range transportation. Collected from a number of those plants, the biosyncrude is converted into synthesis gas, which is cleaned, conditioned, and further converted to fuels or chemicals in an industrial plant complex of reasonable size. Gasification is performed in a high‐pressure entrained flow gasifier at pressures adjusted to those of the subsequently following chemical syntheses. For increased fuel flexibility and conversion of ash rich feed materials, the gasifier is equipped with a cooling screen operated in slagging mode. At Karlsruhe Institute of Technology (KIT), a pilot plant has been erected for process demonstration along the whole process chain. The two MWth fast pyrolysis plant is already in operation since 2009; the five MWth gasifier, the hot gas cleaning section, and a gasoline synthesis via dimethylether are to be finished in 2011. Commissioning of that plant complex will follow in 2012. The technology applied in the bioliq® process chain and on the state of construction of the pilot plant is presented. © 2012 American Institute of Chemical Engineers Environ Prog, 2012
The logistic and construction challenges of an autobahn tunnel with only one accessible portal / Logistische und bautechnische Herausforderungen eines Autobahntunnels mit nur einem zugänglichen Portal
Authors: Balmer Olivier
Published: April 2012

The Graitery Tunnel is about 2.5 km long and lies on the route of the A16 autobahn through the Jura Mountains. It was originally planned to excavate the tunnel from both portals, but geological problems at the south portal have delayed the drive from that end for years. A new logistic plan was required for inner lining and tunnelling. A mobile bridge construction over 60 m long was used in the tunnel, which made it possible to start the lining works while tunnelling was still underway. Due to newly available geological information, the structural calculations for the south drive and the tunnelling scheme were checked. The latter was thoroughly revised with a change to partial‐face excavation in five stages. Although some works will now be completed years later than planned, the tunnel will be handed over to the client for fitting out with not even one and a half years of delay against the original schedule.

Der Tunnel Graitery ist ein rund 2,5 km langer Autobahntunnel der Transjuranne A16. Geplant war, den Tunnel von beiden Portalen her auszubrechen. Geologische Probleme im Bereich des Südportals haben den Gegenvortrieb um Jahre verzögert. Ein neues Logistikkonzept für Innenausbau und Vortrieb war erforderlich. Im Tunnel wurde eine über 60 m lange selbst fahrende Brückenkonstruktion installiert, welche es erlaubte, während des Vortriebs mit dem Innenausbau zu beginnen. Aufgrund neuer geotechnischer Kenntnisse wurden die statischen Berechnungen des Südvortriebs und das Vortriebkonzept überprüft. Letzteres wurde komplett überarbeitet und zu Gunsten eines Teilausbruchs in fünf Etappen geändert. Obwohl einzelne Arbeiten Jahre später als geplant fertig gestellt wurden, wird der Tunnel mit nicht einmal eineinhalb Jahren Verzögerung gegenüber dem ursprünglichen Bauprogramm dem Bauherrn für die Ausrüstungsarbeiten übergeben.
Development and Testing of a New Computerized Link Analysis System
Authors: Zhao Y. , Hignett S. , Mansfield N. J.
Published: April 2012

Link analysis (LA) is a popular ergonomic tool for studying and improving the layout of workspaces. It uses a data (event) recording method to input interactions of human behavior with their environment. The traditional “pen and paper'' method of LA is cumbersome, time consuming, and gives limited outputs. To address these limitations, the computerized link analysis (CLA) system was developed and tested in laboratory and real‐world environments. CLA offers an integrated task analysis tool, including traditional LA functions (layout, event recording) with more detail for operator activities, time‐motion functions, and multioperator data recording. As well as the conventional LA results (link diagrams and link tables), there are additional outputs for time‐event lists (start/end time, duration, chronology, additional notes, importance, and operator ID), and processed link diagrams with the link direction and frequency. © 2012 Wiley Periodicals, Inc.
Continuous measurement of nitrate concentration in a highly event‐responsive agricultural catchment in south‐west of France: is the gain of information useful?
Authors: Ferrant S. , Laplanche C. , Durbe G. , Probst A. , Dugast P. , Durand P. , Sanchez‐Perez J. M. , Probst J. L.
Published: April 2012

A nitrate sensor has been set up to measure every 10 min the nitrate signal in a stream draining a small agricultural catchment dominated by fertilized crops during a 2‐year study period (2006–2008) in the south‐west of France. An in situ sampling protocol using automatic sampler to monitor flood events have been used to assume a point‐to‐point calibration of the sensor values. The nitrate concentration exhibits nonsystematic concentration and dilution effects during flood events. We demonstrate that the calibrated nitrate sensor signal gathered from the outlet is considered to be a continuous signal using the Nyquist–Shannon sampling theorem. The objectives of this study are to quantify the errors generated by a typical infrequent sampling protocol and to design appropriate sampling strategy according to the sampling objectives. Nitrate concentration signal and flow data are numerically sampled to simulate common sampling frequencies. The total fluxes calculated from the simulated samples are compared with the reference value computed on the continuous signal. Uncertainties are increasing as sampling intervals increase; the method that is not using continuous discharge to compute nitrate fluxes bring larger uncertainty. The dispersion and bias computed for each sampling interval are used to evaluate the uncertainty during each hydrological period. High underestimation is made during flood periods when high‐concentration period is overlooked. On the contrary, high sampling frequencies (from 3 h to 1 day) lead to a systematic overestimation (bias around 3%): highest concentrations are overweighted by the interpolation of the concentration in such case. The in situ sampling protocol generates less than 1% of load estimation error and sample highest concentration peaks. We consider useful such newly emerging field technologies to assess short‐term variations of water quality parameters, to minimize the number of samples to be analysed and to assess the quality state of the stream at any time. Copyright © 2012 John Wiley & Sons, Ltd.
Possible involvement of brain‐derived neurotrophic factor in eating disorders
Authors: Nakazato Michiko , Hashimoto Kenji , Shimizu Eiji , Niitsu Tomihisa , Iyo Masaomi
Published: April 2012

Eating disorders (EDs) manifest as abnormal patterns of eating behavior and weight regulation driven by low self‐esteem due to weight preoccupation and perceptions toward body weight and shape. Two major groups of such disorders are anorexia nervosa (AN) and bulimia nervosa (BN). The etiology of EDs is complex and evidence indicates that both biological/genetic and psychosocial factors are involved. Several lines of evidence indicate that brain‐derived neurotrophic factor (BDNF) plays a critical role in regulating eating behaviors and cognitive impairments in the EDs. BDNF is involved in neuronal proliferation, differentiation, and survival during development. BDNF and its tyrosine kinase receptor (TrkB) are expressed in hypothalamic nuclei associated with eating behaviors. A series of studies using BDNF knockout mice and the human BDNF gene indicate an association of BDNF and EDs with predisposition and vulnerability. In the previous studies, serum BDNF levels in subjects with EDs are reduced significantly compared with healthy controls, hence, we proposed that levels of serum BDNF would be a useful diagnostic indicator for EDs. © 2012 IUBMB IUBMB Life, 2012
Contribution of genetic variants to pain susceptibility inParkinson disease
Authors: Greenbaum L. , Tegeder I. , Barhum Y. , Melamed E. , Roditi Y. , Djaldetti R.
Published: April 2012

Background

Pain is a one of the most disturbing non‐motor symptoms ofParkinson disease (PD). The susceptibility to pain varies substantially among patients withPD. The aim of this study was to assess a potential association of genetic variants toPD‐related pain.

Methods

We analysed 20 candidateSNPsfrom 12 genes previously reported to be associated with various pain phenotypes in a homogeneous group of 229IsraeliJewishPDpatients, with and without pain (n = 165 and 64, respectively).

Results

The statistical analysis accounted for the potential influence of demographic and clinical factors. The non‐synonymousrs6746030 single nucleotide polymorphism (SNP) of theSCN9Agene, which alters the coding sequence of the sodium channelNav1.7 (arginine to tryptophan), was nominally associated withPD‐related pain susceptibility (p = 0.037), as well as with central and musculoskeletal pain subtypes independently. The synonymous rs324419SNPof theFAAHgene which encodes fatty acid amide hydrolase, a cannabinoid metabolizing enzyme, was associated withPD‐related pain (p = 0.006) and specifically with the musculoskeletal subtype. TheFAAHhaplotype ofrs324419 andrs2295633SNPs, which was previously associated with the variability in pain response in humans, was also associated withPD‐related pain (p = 0.012) and specifically withPD‐related musculoskeletal pain.

Conclusions

Variants within in theSCN9AandFAAHgenes were associated with the risk of pain inPDpatients. These findings may contribute to our understanding of pain mechanisms ofPDand to direct future therapies.
Concordance of qualitative bone scintigraphy results with presence of clinical complex regional pain syndrome 1: Meta‐analysis of test accuracy studies
Authors: Ringer R. , Wertli M. , Bachmann L.M. , Buck F.M. , Brunner F.
Published: April 2012

Background

To date, no attempt has been made to investigate the agreement between qualitative bone scintigraphy (BS) and the presence of complex regional pain syndrome 1 (CRPS 1) and the agreement between a negative BS in the absence of CRPS 1.

Aims

To summarize the existing evidence quantifying the concordance of qualitative BS in the presence or absence of clinical CRPS 1.

Data Sources

We searched Medline, Embase, Dare and the Cochrane Library and screened bibliographies of all included studies.

Study Eligibility Criteria

We selected diagnostic studies investigating the association between qualitative BS results and the clinical diagnosis of CRPS 1. The minimum requirement for inclusion was enough information to fill the two‐by‐two tables.

Results

Twelve studies met our inclusion criteria and were included in the meta‐analysis. The pooled mean sensitivity of 12 two‐by‐two tables was 0.87 (95% CI, 0.68–0.97) and specificity was 0.69 (95% CI, 0.47–0.85). The pooled mean sensitivity for the subgroup with clearly defined diagnostic criteria (seven two‐by‐two tables) was 0.80 (95% CI, 0.44–0.95) and specificity was 0.73 (95% CI, 0.40–0.91).

Conclusions

Based on this study, clinicians must be advised that a positive BS is not necessarily concordant with presence of absence or CRPS 1. Given the moderate level of concordance between a positive BS in the absence of clinical CRPS 1, discordant results potentially impede the diagnosis of CRPS 1.
PRACTICES AND PROBLEMS IN RESIDENCE HALL PLANNING
Authors: CRANE WILLIAM J.
Published: April 2012

The construction of residence halls should be planned to suit the population, land usage, and financial structure of the college or university. One step in planning for additional residence halls is to assess current practice on similar campuses. Because there are a great many ways in which one institution can vary from another, this step will supply only general information to the planners. Adaptations must be made to fit the local situation.

In an attempt to assess current practices relating to housing for men in moderate‐sized public institutions, questionnaires were sent to 43 colleges and universities of about 2,000 to 8,000 students. Of this group, 39 institutions responded. The operation of residence halls was assessed as to capacity, the reasons for the capacity limits, location, recreation areas, parking areas, food services, types of rooms, lounge areas, equipment, and facilities. The report will be made in terms of percentages of total numbers or actual figures when the percentages are small.
Pupil Opinions of High School Guidance Programs
Authors: GIBSON ROBERT L.
Published: April 2012

The current controversies over educational practices, past and present, European and American, have produced many heated debates and discussions. While many of the issues brought up have not been resolved, there appear to be two important, consistently stated, and agreed upon beliefs which were significant in developing this study: (1) the desirability of a careful examination and evaluation of all phases of our public school program, and (2) the need for trained guidance counselors and organized guidance programs in the public secondary schools.

These would seem to suggest further that the study of current guidance programs would be in order and a number and variety of these have been and are continuing to be undertaken at the local, state, and national levels. However, these studies and evaluations have, for the most part, been undertaken from the adult, staff, guidance specialist, and occasionally parent, viewpoint. This survey represents an attempt to study this phase of the school program from the viewpoint of the group most directly affected—the students, with the belief that an understanding of pupil information about, attitudes toward, and utilization of their school guidance programs would be significant to guidance counselors in secondary school programs and, also, could present implications for counselor trainers directing college training programs in counselor preparation.
Changes of Majors by University Students
Authors: PIERSON ROWLAND R.
Published: April 2012

The study summarized in this paper was motivated by concern as to why Michigan State University students change their academic majors and how they feel about having done so. It was believed that such information would be helpful in suggesting ways in which this University and its constituent high schools could be more effective in aiding entering students with their educational‐vocational planning. The findings of this questionnaire study may be useful to other colleges and universities.
A Summer Program Combining Freshman Orientation, Counseling, and Counselor Preparation
Authors: SEYMOUR JOHN C. , GUTHRIE FAIN A.
Published: April 2012

In recent years the University of Alabama has been faced with the problem of providing adequate counseling and orientation for an ever‐increasing number of new students. Also, increased enrollment in courses taught in the Department of Counseling and Guidance has created a need for expansion of offerings in this area and has required the broadening of practicum experiences.

During the summer of 1959 the University carried out a pilot program in counseling and orientation of new students which promised to satisfy increasing needs in both the areas of service and professional counselor education. The program, which consisted basically of a series of intensive, three‐day sessions of orientation, testing, and counseling of prospective freshmen, was expanded in the summer of 1960 and 1961. The results thus far suggest that this type of program provides an excellent opportunity for contributing to the preparation of counselors and a sound orientation for new students.
GROUP GUIDANCE: Content and Process
Authors: GOLDMAN LEO
Published: April 2012

Group methods of guidance and counseling have been at once a great hope and a great disappointment. Counselors have hoped that group methods would make it possible to use their time more efficiently for transmitting commonly‐needed information and interpretations. This would be especially valuable in schools, where case loads almost universally are too large. But economy of time was only one of the hoped‐for advantages. It seemed logical to expect that boys and girls, and adults too, could benefit from sharing experiences with others and exchanging ideas about the handling of their problems. For some it should be helpful just to know that their problems are not unique. From the counselor's point of view, enriched understanding of his counselees should result from the opportunity to see how each of them functions in the group setting. For these and other anticipated values, counselors in many settings, but especially in schools, looked to group methods for valuable contributions to a total guidance and counseling program.
In vivo antigenotoxic activity of watercress juice (Nasturtium officinale) against induced DNA damage
Authors: Casanova Natalia A. , Ariagno Julia I. , López Nigro Marcela M. , Mendeluk Gabriela R. , Gette María de los A. , Petenatti Elisa , Palaoro Luis A. , Carballo Marta A.
Published: April 2012

The present study was carried out to investigate the genotoxicity as well as possible protective activity against damage induced by cyclophosphamide (CP) of the aqueous juice of watercress (Nasturtium officinale, W.T. Aiton) in vivo. Male and female Swiss mice 7–8 weeks old (N = 48) were treated by gavage with 1 g kg−1 body weight and 0.5 g kg−1 body weight of watercress juice during 15 consecutive days. Genotoxicity and its possible protective effect were tested by the comet assay in peripheral blood cells and the micronucleus test in bone marrow. In addition, biopsies of the bladder, epididymis and testicles of mice were performed to extend the experimental design. Watercress juice per se did not induce genetic damage according to the comet assay and micronucleus study, exhibiting a protective activity against CP (P < 0.05 and P < 0.001, respectively). The comparative analysis of bladder histological changes obtained in the watercress plus CP group against those treated with CP alone suggests a probable protective effect. Further studies are needed in order to establish the protective role of watercress juice against DNA damage. Copyright © 2012 John Wiley & Sons, Ltd.
Design of donors with broad absorption regions and suitable frontier molecular orbitals to match typical acceptors via substitution on oligo(thienylenevinylene) toward solar cells
Authors: Tang Shanshan , Zhang Jingping
Published: April 2012

A series of oligo(thienylenevinylene) derivatives with or without thieno[3,2‐b]thiophene analogs as cores and three types substituent has been investigated at the PBE0/6‐31G(d) and the TD‐PBE0/6‐31+G(d,p) levels to design materials with high performance such as suitable frontier molecular orbital (FMO) energies to match those of [6,6]‐phenyl‐C61‐butyric acid methyl ester (PCBM) and its derivatives, broad absorption spectra, higher and balance transfer property, and better stability. The results reveal that fused cores have slight effects on photophysical properties of investigated derivatives. The electron‐withdrawing or push–pull substituents result in red shifts of absorption spectra and better stabilities for investigated derivatives. The calculated reorganization energies of designed derivatives suggest them to be good potential ambipolar transport materials under the proper operating conditions. The promising donors for PCBM, bisPCBM, PC70BM, and indene‐C60 bisadduct (ICBA) as acceptors are recommended theoretically for solar cells based on the proper match for FMOs between donors and acceptors. Moreover, we have also predicted the mobility of designed molecule with better performance. © 2012 Wiley Periodicals, Inc.
HolT Hunter: Software for identifying and characterizing low‐strain DNA holliday triangles
Authors: Sherman William B.
Published: April 2012

Synthetic DNA nanostructures are most commonly held together via Holliday junctions. These junctions allow for a wide variety of different angles between the double helices they connect. Nevertheless, only constructs with a very limited selection of angles have been built, to date, because of the computational complexity of identifying structures that fit together with low strain at odd angles. I have developed an algorithm that finds over 95% of the possible solutions by breaking the problem down into two portions. First, there is a problem of how smooth rods can form triangles by lying across one another. This problem is easily handled by numerical computation. Second, there is the question of how distorted DNA double helices would need to be to fit onto the rod structure. This strain is calculated directly. The algorithm has been implemented in a Mathematica 8 notebook called Holliday Triangle Hunter. A large database of solutions has been identified. Additional interface software is available to facilitate drawing and viewing models. © 2012 Wiley Periodicals, Inc.
The statistical significance of selected sense–antisense peptide interactions
Authors: Illingworth Christopher J. R. , Chintipalli Sree V. , Serapian Stefano A. , Miller Andrew D. , Veverka Vaclav , Carr Mark D. , Reynolds Christopher A.
Published: April 2012

Sense and antisense peptides, encoded by sense and corresponding antisense DNA strands, are capable of specific interactions that could be a driving force to mediate protein–protein or protein–peptide binding associations. The complementary residue hypothesis suggests that these interactions are founded upon the sum of pairwise interactions between amino acids encoded by corresponding sense and antisense codons. Despite many successful experimental results obtained with the hypothesis, however, the physicochemical basis for these interactions is poorly understood. We examined the potential of the hypothesis for general identification of protein–protein interaction sites, and the possible role of the hypothesis in determining folding in a broad set of protein structures. In addition, we performed a structural study to investigate the binding of a complementary peptide to IL‐1F2. Our results suggest that complementary residue pairs are no more frequent or conserved than average in protein–protein interfaces, and are statistically under‐represented amongst contacting residue pairs in folded protein structures. Although our structural results matched experimental observations of binding between the peptide and IL‐1F2, complementary residue interactions do not appear to be dominant in the bound structure. Overall, our data do not allow us to conclude that the complementary residue hypothesis accounts for specific sense–antisense peptide interactions. © 2012 Wiley Periodicals, Inc.
Attenuation of PTEN perturbs genomic stability via activation of Akt and down‐regulation of Rad51 in human embryonic kidney cells
Authors: Mukherjee Ananda , Karmakar Parimal
Published: April 2012

To address the involvement of PTEN/Akt signaling in DNA repair and genomic stability, we developed a shRNA‐mediated PTEN knockdown cell line from HEK293T cells and evaluated its response to etoposide by analyzing γH2AX and Rad51 foci formation, cell cycle analysis, and chromosome damage. HEK PTEN knockdown cells were impaired in DNA repair associated with loss of G2/M checkpoint and reduced Rad51 foci formation. Furthermore, inhibition of Akt did not restore etoposide‐induced G2/M arrest in PTEN knockdown cells, suggesting that loss of G2/M checkpoint in PTEN knockdown cells is Akt‐independent. On the other hand, these cells become sensitive to etoposide when Akt was inhibited. Thus, loss of G2/M checkpoint and reduction of Rad51‐mediated homologous recombination is responsible for the genomic instability of PTEN knockdown cells where activated Akt additionally contribute to strong survival signal. © 2012 Wiley Periodicals, Inc.
Thermal, mechanical, and rheological characterization of polypropylene/layered double hydroxide nanocomposites
Authors: Lonkar Sunil P. , Therias Sandrine , Leroux Fabrice , Gardette Jean‐Luc , Singh Raj Pal
Published: April 2012

Polypropylene (PP)/organomodified layered double hydroxide (LDH) nanocomposites were prepared in order to examine the influence of LDH content on thermal, mechanical, and rheological properties. The nanostructure examinations by X‐ray diffraction (XRD) and transmission electron microscopy (TEM) confirmed the exfoliated/intercalated dispersion of LDH. Incorporation of the LDH resulted in a noteworthy improvement in the thermal stability of PP. It was shown that the addition of LDH contributed to the reinforcement effect by increasing the elastic modulus. The mechanical performance, as evaluated by stress–strain curves, reveal that PP/LDH hybrid materials showed significant contribution toward increment in elastic modulus, tensile strength but at the expense of impact strength. The rheological response showed a strong influence of LDH particles on the flow behavior of the PP/LDH melt which resulted in enhancement of storage, loss of moduli, and complex viscosity of nanocomposites. Therefore, the nanocomposites have higher moduli but better processibility compared with pure PP. Overall, the results indicated that the LDH particles in nanometer size might act as potential reinforcing agent for polypropylene. POLYM. ENG. SCI., 52:2006–2014, 2012. © 2012 Society of Plastics Engineers
Global optimization of solar thermophotovoltaic systems
Authors: Datas A. , Algora C.
Published: April 2012

In this paper, we present a theoretical model based on the detailed balance theory of solar thermophotovoltaic systems comprising multijunction photovoltaic cells, a sunlight concentrator and spectrally selective surfaces. The full system has been defined by means of 2n + 8 variables (being n the number of sub‐cells of the multijunction cell). These variables are as follows: the sunlight concentration factor, the absorber cut‐off energy, the emitter‐to‐absorber area ratio, the emitter cut‐off energy, the band‐gap energy(ies) and voltage(s) of the sub‐cells, the reflectivity of the cells' back‐side reflector, the emitter‐to‐cell and cell‐to‐cell view factors and the emitter‐to‐cell area ratio. We have used this model for carrying out a multi‐variable system optimization by means of a multidimensional direct‐search algorithm. This analysis allows to find the set of system variables whose combined effects results in the maximum overall system efficiency. From this analysis, we have seen that multijunction cells are excellent candidates to enhance the system efficiency and the electrical power density. Particularly, multijunction cells report great benefits for systems with a notable presence of optical losses, which are unavoidable in practical systems. Also, we have seen that the use of spectrally selective absorbers, rather than black‐body absorbers, allows to achieve higher system efficiencies for both lower concentration and lower emitter‐to‐absorber area ratio. Finally, we have seen that sun‐to‐electricity conversion efficiencies above 30% and electrical power densities above 50 W/cm2 are achievable for this kind of systems. Copyright © 2012 John Wiley & Sons, Ltd.
Growth and spectral properties of Er3+/Yb3+ and Ce3+/Er3+/Yb3+‐doped NaGd(MoO4)2 crystals
Authors: Zhao Yunxia , Huang Yisheng , Lin Zhoubin , Zhang Lizhen , Wang Guofu
Published: April 2012

This paper reports on the growth and spectroscopic properties of Er3+/Yb3+:NaGd(MoO4)2 and Ce3+/Er3+/Yb3+:NaGd(MoO4)2 crystals. Er3+/Yb3+:NaGd(MoO4)2 and Ce3+/Er3+/Yb3+:NaGd(MoO4)2 crystals were grown by the Czochralski method. The investigated polarized spectroscopic properties of both crystals revealed that when the Ce3+ ion was introduced into Ce3+/Er3+/Yb3+:NaGd(MoO4)2 crystal, it could enhance the 1.5 µm fluorescence intensity and decrease the fluorescence lifetime of Ce3+/Er3+/Yb3+:NaGd(MoO4)2 crystal. To sum up the spectral properties of Ce3+/Er3+/Yb3+:NaGd(MoO4)2 crystal, it may be regarded as a potential 1.5 µm Er3+ laser crystal material.
Auxetic warp knit textile structures
Authors: Alderson Kim , Alderson Andrew , Anand Subhash , Simkins Virginia , Nazare Shonali , Ravirala Naveen
Published: April 2012

The design, manufacturing and characterization of warp knit textile structures with enhanced drapeability and energy absorption is reported in this paper. Four textile structures were produced, all based on a triangular or double arrowhead structure, which is known to lead to a negative Poisson's ratio ν. Mechanical testing has confirmed that textile structures can be produced which are auxetic at ± 45° to the warp direction, with ν of up to −0.22 ± 0.03.
Excitonic nonlinearities in single‐wall carbon nanotubes
Authors: Nguyen D. T. , Voisin C. , Roussignol Ph. , Roquelet C. , Lauret J. S. , Cassabois G.
Published: April 2012

Excitons are composite bosons that allow a fair description of the optical properties in solid state systems. The quantum confinement in nanostructures enhances the excitonic effects and impacts the exciton–exciton interactions, which tailor the performances of classical and quantum optoelectronic devices, such as lasers or single‐photon emitters. The excitonic nonlinearities exhibit significant differences between organic and inorganic compounds. Tightly bound Frenkel excitons in molecular crystals are for instance affected by an efficient exciton–exciton annihilation (EEA). This Auger process also governs the population relaxation dynamics in carbon nanotubes that share many physical properties with organic materials. Here, we show that this similarity breaks down for the excitonic decoherence in carbon nanotubes. Original nonlinear spectral‐hole burning experiments bring evidence of pure dephasing induced by exciton–exciton scattering (EES) in the k‐space. This mechanism controls the exciton collision‐induced broadening, as for Wannier excitons in inorganic semiconductors. We demonstrate that this singular behavior originates from the intrinsic one‐dimensionality of excitons in carbon nanotubes, which display unique hybrid features of organic and inorganic systems.
Naphthoquinone Components from Alkanna tinctoria (L.) Tausch Show Significant Antiproliferative Effects on Human Colorectal Cancer Cells
Authors: Huu Tung Nguyen , Du Guang‐Jian , Wang Chong‐Zhi , Yuan Chun‐Su , Shoyama Yukihiro
Published: April 2012

Our research to seek active compounds against human colorectal cancer from the root of Alkanna tinctoria (L.) Tausch led to the isolation of two naphthoquinones, alkannin (1) and angelylalkannin (2). The antiproliferative effects of the two compounds on human colon cancer cells HCT‐116 and SW‐480 were determined by the 3,4‐(5‐dimethylthiazol‐2‐yl)‐5‐(3‐carboxymethoxyphenyl)‐2‐(4‐sulfophenyl)‐2H‐tetrazolium salt (MTS) method. Cell cycle profile and cell apoptosis were determined using flow cytometry. Both of the two compounds showed significant inhibitory effects on the cancer cells. For alkannin (1) and angelylalkannin (2), the median inhibitory concentration (IC50) values were 2.38 and 4.76 µ m for HCT‐116 cells, while for SW‐480 cells they were 4.53 and 7.03 µ m, respectively. The potential antiproliferative mechanisms were also explored. At concentrations between 1–10 µ m, both compounds arrested the cell cycle at the G1 phase and induced cell apoptosis. Copyright © 2012 John Wiley & Sons, Ltd.
Antithrombin Effect of Polyphenol‐Rich Extracts from Black Chokeberry and Grape Seeds
Authors: Bijak Michał , Saluk Joanna , Ponczek Michał Błażej , Nowak Paweł
Published: April 2012

Thrombin is a serine protease that cleaves the peptide bonds in proteins located on the carboxyl side of arginine. Thrombin plays a central role in thromboembolic diseases, which are the major cause of mortality. The aim of the study was to estimate the effects of plant extracts on proteolytic properties of thrombin. Thrombin was incubated with polyphenol‐rich extracts from berries of Aronia melanocarpa or seeds of Vitis vinifera (0.5, 5, 50 µg/mL) and with polyphenols ((+)‐catechin, (−)‐epicatechin, gallic acid, chlorogenic acid, procyanidin B1, cyanidin, cyanidin 3‐glucoside, quercetin). The in vitro experiments showed that both extracts in all used concentrations inhibited proteolytic activity of thrombin observed as inhibition of thrombin‐induced fibrinogen polymerization, stabilized fibrin formation, and platelet aggregation. Moreover, thrombin amidolytic activity was inhibited by polyphenols belonging to the flavonoid class. Results presented in this study indicate that polyphenol‐rich extracts from berries of A. melanocarpa and seeds of V. vinifera may become promising dietary supplements in the prevention of thrombotic states. Copyright © 2012 John Wiley & Sons, Ltd.
Antiproliferative Activity of Polygonaceae Species from the Carpathian Basin against Human Cancer Cell Lines
Authors: Lajter Ildikó , Zupkó István , Molnár Judit , Jakab Gusztáv , Balogh Lajos , Vasas Andrea , Hohmann Judit
Published: April 2012

Aqueous and organic extracts of 27 selected species from five genera (Fallopia, Oxyria, Persicaria, Polygonum and Rumex) of the family Polygonaceae occurring in the Carpathian Basin were screened in vitro for antiproliferative activity against HeLa (cervix epithelial adenocarcinoma), A431 (skin epidermoid carcinoma) and MCF7 (breast epithelial adenocarcinoma) cells, using the 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assay. A total of 196 n‐hexane, chloroform, 50% methanol or water extracts of different plant parts were investigated. It was found that extracts of Polygonum hydropiper, Rumex acetosa, Rumex alpinus, Rumex aquaticus, Rumex scutatus and Rumex thyrsiflorus at 10 or 30 µg/mL demonstrated substantial cell growth inhibitory activity (at least 50% inhibition of cell proliferation) against one or more cell lines. R. acetosa and R. thyrsiflorus proved to be the most active and are considered worthy of activity‐guided phytochemical investigations. Copyright © 2012 John Wiley & Sons, Ltd.
Superhydrophobic polymer‐particle composite films produced using various particle sizes
Authors: Karapanagiotis Ioannis , Manoudis Panagiotis N. , Savva Achilleas , Panayiotou Costas
Published: April 2012

Hydrophilic alumina (Al2O3) nanoparticles (25, 35, and 150 nm) are dispersed in different concentrations in solutions of a commercial hydrophobic poly(alkyl siloxane) (Silres BS‐290), and the suspensions are sprayed on glass surfaces. Static contact angles (θS), measured on surfaces of siloxane‐nanoparticle composite films that were prepared from dilute dispersions, increase rapidly with particle concentration. Composite films prepared from concentrated dispersions exhibit a maximum, constant θS (at saturation θS is 160°), which is not affected by the size of the particles. These films exhibit also very small contact angle hysteresis (5°), which is also independent of the particle size. Consequently, the same superhydrophobic character can be induced in siloxane films using nanoparticles, which can range from a few up to several tenths of nanometers. However, the particle size and more precisely the particle specific surface area affects dramatically the minimum critical particle concentration, which must be used in the dispersions to induce superhydrophobicity on the surface of the composite films, that is, to achieve θS = 150°. It is shown that critical particle concentration decreases exponentially with specific surface area. This result can be important for manufacturers of superhydrophobic surfaces who are interested in having a good control on the wettability of the composite films. Copyright © 2012 John Wiley & Sons, Ltd.
The architecture of collaboration
Authors: Fjeldstad Øystein D. , Snow Charles C. , Miles Raymond E. , Lettl Christopher
Published: April 2012

Firms increasingly face competitive pressures related to rapid and continuous adaptation to a complex, dynamic, and highly interconnected global environment. Pressing challenges include keeping pace with shorter product life cycles, incorporating multiple technologies into the design of new products, cocreating products and services with customers and partners, and leveraging the growth of scientific and technical knowledge in many sectors. In response, we observe experimentation with new organization designs that are fundamentally different from existing forms of organizing. We propose that these new designs are based on an actor‐oriented architectural scheme composed of three main elements: (1) actors who have the capabilities and values to self‐organize; (2) commons where the actors accumulate and share resources; and (3) protocols, processes, and infrastructures that enable multi‐actor collaboration. We demonstrate the usefulness of the actor‐oriented scheme by applying it to organizations drawn from four different sectors: global professional services, open source software development, computer equipment, and national defense. We discuss the implications of the actor‐oriented architectural scheme for future research on organizational forms as well as for managers who are involved in designing organizations. Copyright © 2012 John Wiley & Sons, Ltd.
Nanotoxicity: How the Body Develops A Way to Reduce the Toxicity of Carbon Nanotubes
Authors: Riehemann Kristina
Published: April 2012

The interaction of nanoparticles with cells and organisms are often the focus of biomedical, material, and environmental research. This article highlights a paper by Yuliang Zhao, Chunying Chen, Ruhong Zhou, and co‐workers (Proc. Natl. Acad. Sci. USA 2011, 108, 16968), which brings a new aspect to the discussion about purpose and mechanisms underlying the reaction of an organism with nanoparticles. The interactions of carbon nanotubes with cells were investigated with regard to the defense mechanisms of the body against foreign materials developed during evolution. Such mechanisms are not only important for nanotoxicity research, but also for targeting nanoparticles in medical applications. The cited article thus gives a new focus to an important aspect of nanotechnology, which will determine the application aspects of this technology in future: the approach of biological systems to nanosized particles.
Toxicity thresholds for juvenile freshwater musselsEchyridella menziesiiand crayfishParanephrops planifrons, after acute or chronic exposure toMicrocystissp
Authors: Clearwater S. J. , Wood S.A. , Phillips N.R. , Parkyn S.M. , Van Ginkel R. , Thompson K.J.
Published: April 2012

Survival of juvenile freshwater mussels (Echyridella menziesii(Gray, 1843) formerly known asHyridella menziesi) and crayfish (Paranephrops planifrons, White, 1842) decreased after four days exposure to microcystin‐containing cell‐free extracts (MCFE) ofMicrocystissp. at concentrations typical of severe cyanobacterial blooms. Crayfish survival was 100, 80, and 50% in microcystin concentrations of 1339, 2426, and 11146 μg L−1respectively, and shade‐ and shelter‐seeking behavior was negatively affected when concentrations were ≥2426 μg L−1. Mussel survival decreased to 92% and reburial rates decreased to 16% after exposure for 96 h to MCFE containing microcystins at concentrations of 5300 μg L−1. Crayfish survival was 100% when fed freeze‐driedMicrocystissp. incorporated into an artificial diet (6–100 μg microcystin kg−1ww) at dietary doses from 0.03 to 0.55 μg g−1body weight d−1for 27 days. Specific growth rate was significantly lower in crayfish fed ≥0.15 μg g−1body weight day−1compared with controls, but not compared with a diet incorporating nontoxic cyanobacteria. Microcystins accumulated preferentially in crayfish hepatopancreas and mussel digesta as MCFE or dietary concentrations increased. These laboratory data indicate that, assuming dissolved oxygen concentrations remain adequate, and no simultaneous exposure to liveMicrocystissp. cells, cell‐free microcystins will only be a significant stressor to juvenile crayfish and mussels in severeMicrocystissp. blooms. In contrast, crayfish were negatively affected by relatively low concentrations of microcystins in artificial diets compared with those measured locally in benthic cyanobacterial mats. © 2012 Wiley Periodicals, Inc. Environ Toxicol 29: 487–502, 2014.
Prenatal di‐n‐butyl phthalate exposure alters reproductive functions at adulthood in male rats
Authors: Giribabu Nelli , Sainath Sri Bhashyam , Sreenivasula Reddy Pamanji
Published: April 2012

This study was aimed to investigate the reproductive health in adult male rats exposed to di‐n‐butyl phthalate (DBP) during embryonic development. Pregnant rats were injected with DBP and F1 male rats were weaned and on postnatal day 100, used for mating with normal cycling females to assess reproductive performance. After completion of cohabitation period, rats were analyzed for other reproductive end points. Transplacental exposure to DBP significantly decreased fertility in adult male rats. Prenatal exposure to DBP significantly decreased sperm density, number of motile sperms, viable sperms, and hypoosmotic swelling tail coiled sperms with an increase in morphological abnormalities in sperms. Testicular steroidogenic enzyme activity levels and serum testosterone levels were significantly decreased in rats exposed to DBP during embryonic development. In conclusion, transplacental exposure to DBP impairs male reproductive performance by decreasing steroidogenesis and spermatogenesis. © 2012 Wiley Periodicals, Inc. Environ Toxicol 29: 534–544, 2014.
Response to Intervention and the Changing Roles of Schoolwide Personnel
Authors: Bean Rita , Lillenstein Jennifer
Published: April 2012

Interviews and observations were conducted in five schools using a Response to Instruction and Invention framework to investigate (a) changes in role‐ expectations and functions for educators, (b) perceptions about their changing roles, and (c) skills needed to be effective in this systemic effort to improve literacy instruction for all students. Findings included: changes in role‐expectations are essential and inevitable. Essential skill sets included: in‐depth understanding of literacy assessment and instruction and of how to differentiate instruction, ability to use data for instructional decision making, increased collaboration and reflective dialogue, and a commitment to life‐long learning. Shared leadership was evident in all schools, with all personnel involved in efforts to improve literacy learning.
An analytic initial-state parton shower
Authors: Kilian Wolfgang , Reuter Jürgen , Schmidt Sebastian , Wiesler Daniel
Published: April 2012

Abstract

We present a new algorithm for an analytic parton shower. While the algorithm for the final-state shower has been known in the literature, the construction of an initialstate shower along these lines is new. The aim is to have a parton shower algorithm for which the full analytic form of the probability distribution for all branchings is known. For these parton shower algorithms it is therefore possible to calculate the probability for a given event to be generated, providing the potential to reweight the event after the simulation. We develop the algorithm for this shower including scale choices and angular ordering. Merging to matrix elements is used to describe high-energy tails of distributions correctly. Finally, we compare our results with those of other parton showers and with experimental data from LEP, Tevatron and LHC.
Epigenetic regulation of 5‐lipoxygenase in the phenotypic plasticity of valvular interstitial cells associated with aortic valve stenosis
Authors: Nagy Edit , Bäck Magnus
Published: April 2012

Valvular interstitial cells (VICs) are of mesenchymal origin and may differentiate into immune‐like cells. This phenotypic plasticity is a key feature of aortic valve stenosis, but the role of epigenetic mechanisms has not previously been explored. Here we compared normal and calcified human aortic valve tissue. Calcified tissue exhibited decreased DNA‐methylation in the promoter of the gene encoding the proinflammatory enzyme 5‐lipoxygenase (5‐LO), accompanied by increased 5‐LO mRNA levels. Treatment of cultured VICs with the DNA methyltransferase inhibitor: 5‐Aza‐2’‐deoxycytidine increased 5‐LO mRNA levels and leukotriene production. These findings provide a first piece of evidence for epigenetic modifications of VICs in valvular heart disease.