bluuebunny/crossref_metadata_2025 huggingface dataset:
A Visual Study of Vortex Instabilities in the Wake of a Rotor in Hover
Authors: Ohanian Christopher V. , McCauley Gregory J. , Savaş Ömer
Published: September 2012

A visual study of the instability characteristics of the helical vortex filaments trailing from the tips of a three-bladed lifting rotor in a water tank is presented. The rotor diameter was 25.4 cm, and its rotation rate ranged from 4 to 12 revolutions per second. Soon after their formation,
the vortex filaments developed long- and short-wave instabilities. In the long-wave instability mode, two of the three vortices coming off the rotor orbited around each other and merged in about 0.4 of the theoretical orbit time of equistrength two-dimensional vortices, after which the third
vortex joined the merger to form a single, apparently turbulent helical vortex filament. The wavelengths of the short-wave instabilities were about 0.4 of the wake radius, about 17 cycles over the circumference. The short waves exhibited a linear growth rate during the first half of their
orbital motion and an exponential growth prior to merging. The linear growth rate was about 0.0034 D/rad. The e-folding time for the exponential growth rate was about 0.52 rad.
Fine-scale features on the sea surface in SAR satellite imagery – Part 1: Simultaneous in-situ measurements
Authors: Soloviev A. , Maingot C. , Matt S. , Dodge R. E. , Lehner S. , Velotto D. , Brusch S. , Perrie W. , Hochberg E.
Published: September 2012

Abstract. This work is aimed at identifying the origin of fine-scale features on the sea surface in synthetic aperture radar (SAR) imagery with the help of in-situ measurements as well as numerical models (presented in a companion paper). We are interested in natural and artificial features starting from the horizontal scale of the upper ocean mixed layer, around 30–50 m. These features are often associated with three-dimensional upper ocean dynamics. We have conducted a number of studies involving in-situ observations in the Straits of Florida during SAR satellite overpass. The data include examples of sharp frontal interfaces, wakes of surface ships, internal wave signatures, as well as slicks of artificial and natural origin. Atmospheric processes, such as squall lines and rain cells, produced prominent signatures on the sea surface. This data has allowed us to test an approach for distinguishing between natural and artificial features and atmospheric influences in SAR images that is based on a co-polarized phase difference filter.
Problems and Solution Proposals for SMEs in Turkey
Authors: Kaya Sarp , Alpkan Lütfihak
Published: September 2012

The purpose of this project is to present the problems the SMEs' encounter during providing management and financial requirements, probe how they can solve mentioned problems with as less help as possible within their own organization and offer the employer solutions in micro dimensions. While the SMEs' definitions will be located in the second part, the third part will include the weighting of their advantages and disadvantages. In addition to that, the fourth part will introduce suggestions to solve the problems in question that the SMEs come across. Rounding off, part five will discuss the selection of financial instruments during the stage of providing financial requirements for the SMEs, the mistakes done during their application and offer further solution offers for mentioned problems.
UBR5 Gene Mutation Is Associated with Familial Adult Myoclonic Epilepsy in a Japanese Family
Authors: Kato Takeo , Tamiya Gen , Koyama Shingo , Nakamura Tomohiro , Makino Satoshi , Arawaka Shigeki , Kawanami Toru , Tooyama Ikuo
Published: September 2012

The causal gene(s) for familial adult myoclonic epilepsy (FAME) remains undetermined. To identify it, an exome analysis was performed for the proband in a Japanese FAME family. Of the 383 missense/nonsense variants examined, only c.5720G>A mutation (p.Arg1907His) in the UBR5 gene was found in all of the affected individuals in the family, but not in the nonaffected members. Such mutation was not found in any of the 85 healthy individuals in the same community nor in any of the 24 individuals of various ethnicities. The present study demonstrated an FAME-associated mutation in the UBR5 gene, which is located close to the reported locus linked to Japanese FAME families.
Inter- and intra-observer reliability of experienced and inexperienced observers for the Qualitative Behaviour Assessment in dairy cattle
Authors: Bokkers EAM , de Vries M , Antonissen ICMA , de Boer IJM
Published: September 2012

Qualitative Behaviour Assessment (QBA) is part of the Welfare Quality® protocol for dairy cattle, although its inter- and intra-observer reliability have not been reported. This study evaluated inter- and intra-observer reliability of the QBA for dairy cattle in experienced and inexperienced observers using videos. Eight experienced observers performed the QBA (20 descriptors) twice for 16 video clips (60 s per clip; series 1) showing 4-17 animals. They assessed another 11 video clips showing herds (4 shots of 30 s per clip; series 2). Ten inexperienced observers performed the QBA on both video series one time. Inter-observer reliability of experienced observers ranged from slight to moderate (both assessments of series 1), and from low to high (series 2) for descriptors, and from slight to moderate for the QBA score. Inter-observer reliability of inexperienced observers ranged from low to moderate (series 1), and from low to high (series 2) for descriptors, and was moderate (both series) for the QBA score. Intra-observer correlations varied largely per descriptor and observer. They were both negative and positive, and ranged from low to very high. High correlations, however, were not necessarily associated with low paired differences. Values of half of the descriptors and the QBA score differed amongst experienced and inexperienced observers. The QBA appears insufficiently reliable as a tool for welfare assessment in dairy cattle.
Applying welfare training in global commercial settings
Authors: Butterworth A , Whittington P , Hammond-Seaman A
Published: September 2012

Around the world, people who care for animals as stock-keepers, stockmen, farmers, producers are placed in a position where they can greatly influence the quality of life of the animals they manage. A stock-keeper's viewpoint on animal welfare and animal care will be enormously influenced by their cultural frame, how animals are viewed in the society where they live, and how much ‘permission to care’ the individual stockman sees as being granted to them in the place where they work. Sometimes the capacity to care is subsumed by commercial production pressures, lack of time, lack of motivation, perceived lack of resources, perceived lack of ‘value’ for individual animals, lack of perception of animal issues, or sometimes through a lack of knowledge or exposure to concepts of animal care and welfare. The extent and focus of animal welfare training is moulded by the needs of the audience, the company, the retailer or the legislator. For these reasons ‘one size fits all’ training is not usually appropriate, although there may be some general rules which can be applied to nearly all welfare training. These general rules include: do not start by importing values and technology/procedures which those trained cannot use; understand why the people you train do what they do; the initial training should be sympathetic to local knowledge and resources; engage with the industry and its affiliates and if at all possible, obtain government, professional and academic support and involvement; and beware that in the absence of knowledge and training, new technologies and new procedures can create new welfare problems.
Le médecin est-il un guérisseur? Une étude anthropologique auprès de cliniciens hospitaliers à Montréal
Authors: Bourdon Marie-Claude
Published: September 2012

Toutes les sociétés ont leurs façons d’expliquer la souffrance et la guérison. Bien que ces modèles explicatifs et les stratégies thérapeutiques qui y sont reliées varient beaucoup d’une culture et d’une époque à l’autre, on trouve des guérisseurs partout. Dans la société occidentale, ce sont les médecins formés dans le cadre de la biomédecine qui dominent le champ de la guérison. Est-ce à dire que les médecins sont des guérisseurs? Mais d’abord, qu’est-ce que la guérison pour des pédiatres pratiquant dans une grande ville comme Montréal? Cet article est le fruit d’une recherche de maîtrise qui a été menée au Centre hospitalier universitaire mère-enfant Sainte-Justine de Montréal, un hôpital de haut niveau desservant une population multiculturelle. Il s’appuie sur une série d’entrevues en profondeur réalisées avec des médecins de plusieurs spécialités. Les entretiens explorent le concept de la guérison à travers différents thèmes qui apparaissent de façon récurrente dans la littérature anthropologique sur le sujet, tels les thèmes du don, de la transformation et du pouvoir.
Investigation of In Situ and Conventional Post‐Weld Heat Treatments on Dual‐Laser‐Beam‐Welded γ‐TiAl‐Based Alloy
Authors: Liu Jie , Ventzke Volker , Staron Peter , Schell Norbert , Kashaev Nikolai , Huber Norbert
Published: September 2012

This paper describes a way to improve the microstructure and mechanical properties of welding seams by in situ and conventional post‐weld heat treatments for laser beam welding of the Ti–45Al–5Nb–0.2C–0.2B alloy. The seams are crack‐free with reduced longitudinal residual stress and higher elongation to fraction after post‐weld heat treatment. The welding zone consists of α2 after welding, transforms to a massive γ during in situ post‐weld heat treatment, and finally forms a convoluted microstructure after conventional heating. The phase composition across the welding zone is discussed.
Enhanced Omnidirectional Photovoltaic Performance of Solar Cells Using Multiple‐Discrete‐Layer Tailored‐ and Low‐Refractive Index Anti‐Reflection Coatings
Authors: Yan Xing , Poxson David J. , Cho Jaehee , Welser Roger E. , Sood Ashok K. , Kim Jong Kyu , Schubert E. Fred
Published: September 2012

An optimized four‐layer tailored‐ and low‐refractive index anti‐reflection (AR) coating on an inverted metamorphic (IMM) triple‐junction solar cell device is demonstrated. Due to an excellent refractive index matching with the ambient air by using tailored‐ and low‐refractive index nanoporous SiO2 layers and owing to a multiple‐discrete‐layer design of the AR coating optimized by a genetic algorithm, such a four‐layer AR coating shows excellent broadband and omnidirectional AR characteristics and significantly enhances the omnidirectional photovoltaic performance of IMM solar cell devices. Comparing the photovoltaic performance of an IMM solar cell device with the four‐layer AR coating and an IMM solar cell with the conventional SiO2/TiO2 double layer AR coating, the four‐layer AR coating achieves an angle‐of‐incidence (AOI) averaged short‐circuit current density, JSC, enhancement of 34.4%, whereas the conventional double layer AR coating only achieves an AOI‐averaged JSC enhancement of 25.3%. The measured reflectance reduction and omnidirectional photovoltaic performance enhancement of the four‐layer AR coating are to our knowledge, the largest ever reported in the literature of solar cell devices.
Unstable transmission of a familial complex chromosome rearrangement
Authors: van Binsbergen Ellen , Hochstenbach Ron , Giltay Jacques , Swinkels Marielle
Published: September 2012

Complex chromosome rearrangements (CCRs) are rare genomic structural aberrations involving three or more breakpoints on two or more chromosomes. About one‐third of all CCRs are familial. Transmittance of such a CCR results either in genomic imbalance due to abnormal segregation at meiosis I or is stably passed on to the next generation. Here we present a phenotypically normal mother with a CCR involving chromosomes 1, 3, and 5 that gave birth to a phenotypically abnormal son. The boy presented with hypotonia, mild facial dysmorphisms, and severe intellectual disability. Conventional karyotyping revealed the same apparently balanced CCR as in the mother. However, by use of array‐comparative genome hybridization (array‐CGH) and fluorescence in situ hybridization (FISH) we discovered that one of the derivative chromosomes in the patient contained a de novo rearrangement. It appears that during transmission of the CCR, an additional de novo deletion and duplication had arisen in one of the derivative chromosomes. We speculate that this was the result of the inverted duplication with a distal deletion mechanism. We also demonstrate the importance of high‐resolution breakpoint analysis in CCRs and stress that genetic counseling of a familial CCR is not straightforward. To our knowledge, this would be the first description of this mechanism operating on a structurally abnormal chromosome. © 2012 Wiley Periodicals, Inc.
Analysis of the WISP3 gene in Indian families with progressive pseudorheumatoid dysplasia
Authors: Dalal Ashwin , Bhavani G Sri Lakshmi , Togarrati Padma Priya , Bierhals Tatjana , Nandineni Madhusudan R. , Danda Sumita , Danda Debashish , Shah Hitesh , Vijayan Sandeep , Gowrishankar Kalpana , Phadke Shubha R , Bidchol Abdul Mueed , Rao Anand Prahalad , Nampoothiri Sheela , Kutsche Kerstin , Girisha K.M.
Published: September 2012

Progressive pseudorheumatoid dysplasia (PPD) is a progressive skeletal syndrome characterized by stiffness, swelling and pain in multiple joints with associated osteoporosis in affected patients. Radiographically, the predominant features resemble a spondyloepiphyseal dysplasia. Mutations in the WISP3 gene are known to cause this autosomal recessive condition. To date, only a limited number of studies have looked into the spectrum of mutations causing PPD. We report on clinical features and WISP3 mutations in a large series of Indian patients with this rare skeletal dysplasia. Families with at least one member showing clinical and radiologic features of PPD were recruited for the study. Symptoms, signs and radiographic findings were documented in 35 patients from 25 unrelated families. Swelling of small joints of hands and contractures are the most common presenting features. Mutation analysis was carried out by bidirectional sequencing of the WISP3 gene in all 35 patients. We summarize the clinical features of 35 patients with PPD and report on 11 different homozygous mutations and one instance of compound heterozygosity. Eight (c.233G>A, c.340T>C, c.348C>A, c.433T>C, c.682T>C, c.802T>G, c.947_951delAATTT, and c.1010G>A) are novel mutations and three (c.156C>A, c.248G>A, and c.739_740delTG) have been reported previously. One missense mutation (c.1010G>A; p.Cys337Tyr) appears to be the most common in our population being seen in 10 unrelated families. This is the largest cohort of patients with PPD in the literature and the first report from India on mutation analysis of WISP3. We also review all the mutations reported in WISP3 till date. © 2012 Wiley Periodicals, Inc.
Spectrofluorimetric method for the determination of sulpiride in pharmaceutical preparations and human plasma through derivatization with 2‐cyanoacetamide
Authors: Shah Jasmin , Jan M. Rasul , Khan M. Naeem , Shah Sultan
Published: September 2012

A sensitive and accurate spectrofluorimetric method has been developed for the determination of sulpiride in pharmaceutical preparations and human plasma. The developed method is based on the derivatization reaction of 2‐cyanoacetamide with sulpiride in 30% ammonical solution. The fluorescent derivatized reaction product exhibited maximum fluorescence intensity at 379 nm after excitation at 330 nm. The optimum conditions for derivatization reactions were studied and the fluorescence intensity versus concentration plot was found to be linear over the concentration range 0.2–20.0 µg/mL with a correlation coefficient of 0.9985. The limit of detection (LOD) and limit of quantification (LOQ) were found to be 0.82 and 2.73 ng/mL, respectively. The proposed method was validated according to ICH guidelines. The effects of common excipients and co‐administered drugs were also studied. The accuracy of the method was checked using the standard addition method and percent recoveries were found to be in the range of 99.00–101.25% for pharmaceutical preparations and 97.00–97.80% for spiked human plasma. The method was successfully applied to commercial formulations and the results obtained for the proposed method were compared with a high‐performance liquid chromatography reference method and statistically evaluated using the Student's t‐test for accuracy and the variance ratio F‐test for precision. A reaction pathway was also proposed. Copyright © 2012 John Wiley & Sons, Ltd.
ATP and ADP actin states
Authors: Kudryashov Dmitri S. , Reisler Emil
Published: September 2012

This minireview is dedicated to the memory of Henryk Eisenberg and honors his major contributions to many areas of biophysics and to the analysis of macromolecular states and interactions in particular. This work reviews the ATP and ADP states of a ubiquitous protein, actins, and considers the present evidence for and against unique, nucleotide‐dependent conformations of this protein. The effects of ATP and ADP on specific structural elements of actins, its loops and clefts, as revealed by mutational, crosslinking, spectroscopic, and EPR methods are discussed. It is concluded that the existing evidence points to dynamic equilibria of these structural elements among various conformational states in both ATP‐ and ADP‐actins, with the nucleotides impacting the equilibria distributions. © 2012 Wiley Periodicals, Inc. Biopolymers 99: 245–256, 2013.
Synthesis and Characterization of Rhenabenzyne Complexes
Authors: Chen Jiangxi , Shi Chuan , Sung Herman H. Y. , Williams Ian D. , Lin Zhenyang , Jia Guochen
Published: September 2012

Reactions of [ReH5(PMe2Ph)3] with alkynols HC≡CC(OH)(R)C≡CSiMe3 (R=tBu, iPr, 1‐adamantyl) in the presence of HCl give the vinylcarbyne complexes [Re{≡CCHC(R)C≡CSiMe3}Cl2(PMe2Ph)3], which react with tBuMgCl to give [Re{≡CCHC(R)C≡CSiMe3}HCl(PMe2Ph)3]. Treatment of [Re{≡CCHC(R)C≡CSiMe3}HCl(PMe2Ph)3] with nBu4NF gives [Re{≡CCHC(R)C≡CH}HCl(PMe2Ph)3], which first isomerizes to the bicyclic complexes [Re{CHCHC(R)CCH}Cl(PMe2Ph)3], and then to the rhenabenzynes [Re{≡CCHC(R)CHCH}Cl(PMe2Ph)3]. The NMR spectroscopic and structural data as well as the aromatic stabilization energy (ASE) and nucleus‐independent chemical‐shift (NICS) values suggest that these rhenabenzynes have aromatic character.
Molecular scaffolds underpinning macroglial polarization: An analysis of retinal Müller cells and brain astrocytes in mouse
Authors: Enger Rune , Gundersen Georg Andreas , Haj‐Yasein Nadia Nabil , Eilert‐Olsen Martine , Thoren Anna Elisabeth , Vindedal Gry Fluge , Petersen Pétur Henry , Skare Øivind , Nedergaard Maiken , Ottersen Ole Petter , Nagelhus Erlend A.
Published: September 2012

Key roles of macroglia are inextricably coupled to specialized membrane domains. The perivascular endfoot membrane has drawn particular attention, as this domain contains a unique complement of aquaporin‐4 (AQP4) and other channel proteins that distinguishes it from perisynaptic membranes. Recent studies indicate that the polarization of macroglia is lost in a number of diseases, including temporal lobe epilepsy and Alzheimer's disease. A better understanding is required of the molecular underpinning of astroglial polarization, particularly when it comes to the significance of the dystrophin associated protein complex (DAPC). Here, we employ immunofluorescence and immunogold cytochemistry to analyze the molecular scaffolding in perivascular endfeet in macroglia of retina and three regions of brain (cortex, dentate gyrus, and cerebellum), using AQP4 as a marker. Compared with brain astrocytes, Müller cells (a class of retinal macroglia) exhibit lower densities of the scaffold proteins dystrophin and α‐syntrophin (a DAPC protein), but higher levels of AQP4. In agreement, depletion of dystrophin or α‐syntrophin—while causing a dramatic loss of AQP4 from endfoot membranes of brain astrocytes—had only modest or insignificant effect, respectively, on the AQP4 pool in endfoot membranes of Müller cells. In addition, while polarization of brain macroglia was less affected by dystrophin depletion than by targeted deletion of α‐syntrophin, the reverse was true for retinal macroglia. These data indicate that the molecular scaffolding in perivascular endfeet is more complex than previously assumed and that macroglia are heterogeneous with respect to the mechanisms that dictate their polarization. © 2012 Wiley Periodicals, Inc.
Chromosome stability in tonsillar squamous cell carcinoma is associated with HPV16 integration and indicates a favorable prognosis
Authors: Mooren Jeroen J. , Kremer Bernd , Claessen Sandra M.H. , Voogd Adri C. , Bot Fredrik J. , Peter Klussmann J. , Huebbers Christian U. , Hopman Anton H.N. , Ramaekers Frans C.S. , Speel Ernst‐Jan M.
Published: September 2012

Tonsillar squamous cell carcinoma (TSCC) is frequently associated with human papillomavirus (HPV) and chromosome instability. Data from cellular model systems are, however, controversial concerning a relation between HPV and chromosome instability development. Here we studied this association in 77 primary TSCC with known clinical outcome and cell cycle protein expression profiles. Thirty‐two tumors (42%) showed HPV16‐integration. All 77 cases were analyzed by fluorescence in situ hybridization using chromosome 1‐ and 7‐specific centromere DNA probes to detect chromosome instability, indicated by the presence of chromosome imbalances and/or polyploidization for these chromosomes. In addition, eight HPV‐positive dysplasias, seven of which were adjacent to a carcinoma, were analyzed. Disomy for chromosome 1 and 7 was present in 29 out of 77 TSCC (38%), of which 19 were HPV16‐positive (p = 0.002). Aneusomy was observed in the remaining 48 TSCC, of which 13 were HPV‐positive. Aneusomies correlated significantly with tobacco‐ and alcohol consumption (p = 0.001 and p = 0.016, respectively) and a higher T‐stage (p = 0.018). Both HPV‐positivity and chromosome disomy were significantly associated with a favorable disease‐free survival (p = 0.001 and p = 0.025, respectively). Particularly in the HPV16‐positive group chromosome instability is a very strong indicator for an unfavorable prognosis (p = 0.032). In the dysplasias an identical HPV and chromosome copy number status was identified as in the adjacent tumors. We conclude that HPV‐positive TSCC and their precursor lesions are more often genetically stable than HPV‐negative lesions and that these tumors are associated with a favorable prognosis. Chromosome instability is an indicator for unfavorable prognosis, particularly in the HPV‐positive patient group.
Variationally determined electronic states for the theoretical analysis of intramolecular interaction. II. Qualitative nature of the PO bond in phosphine oxides
Authors: Yamada Kenta , Koga Nobuaki
Published: September 2012

We have developed a space‐restricted wave function (SRW) method for the analysis of various types of intramolecular interactions. In this study, we demonstrate the applicability of our SRW method to the analysis of the nature of the PO bond in phosphine oxide (R3PO), one of the hypervalent molecules. An interesting character of this bond has been extensively studied by focusing on the negative hyperconjugation of the O lone pair (nO) with the R3P group. We reinvestigated the nature of the bond in terms of a change in total energy to produce evidence for the validity of our method. The electronic states without the interaction involving three nO orbitals (R3P+−O−) produced by the method were used as reference states in the assessment of the effects of this nO–R3P interaction. The result confirms that this interaction plays an essential role in the nature of the bond and occurs between the nO orbitals and the PR antibonding orbitals, in agreement with previous studies. A molecular orbital (MO)‐pair analysis technique shows that the nO–R3P interaction is decomposed into the negative hyperconjugation and the Pauli repulsion. Considering a reference state where the PO bond is completely broken (R3P2+···O2−) at an interacting distance, PO bond formation is attributed to one σ bond plus two 0.5 π bonds. This is equivalent to three banana bonds highly polarized to the O atom. Consequently, the SRW method suggested improved explanations of the nature of the PO bond. © 2012 Wiley Periodicals, Inc.
Electrochemical Behaviors of Adenosine‐5′‐triphosphate on Molecular Wire Modified Carbon Paste Electrode and Its Sensitive Detection
Authors: Sun Wei , Xu Li , Li Tongtong , Wang Xiuzhen , Li Guangjiu , Sun Zhenfan
Published: September 2012

A new electrochemical method was proposed for the determination of adenosine‐5′‐triphosphate (ATP) based on the electrooxidation at a molecular wire (MW) modified carbon paste electrode (CPE), which was fabricated with diphenylacetylene (DPA) as the binder. A single well‐defined irreversible oxidation peak of ATP appeared on MW‐CPE with adsorption‐controlled process and enhanced electrochemical response in a pH 3.0 Britton‐Robinson buffer solution, which was due to the presence of high conductive DPA in the electrode. The electrochemical parameters of ATP were calculated with the electron transfer coefficient (α) as 0.54, the electron transfer number (n) as 1.9, the apparent heterogeneous electron transfer rate constant (ks) as 2.67 × 10−5 s−1 and the surface coverage (ΓT) as 4.15 × 10−10 mol cm−2. Under the selected conditions the oxidation peak current was proportional to ATP concentration in the range from 1.0 × 10−7 mol L−1 to 2.0 × 10−3 mol L−1 with the detection limit as 1.28 × 10−8 mol L−1 (3σ) by sensitive differential pulse voltammetry. The proposed method showed good selectivity without the interferences of coexisting substances and was successful applied to the ATP injection samples detection.
DC‐gated high resolution three‐dimensional lung imaging during free‐breathing
Authors: Weick Stefan , Breuer Felix A. , Ehses Philipp , Völker Michael , Hintze Christian , Biederer Jürgen , Jakob Peter M.
Published: September 2012

Purpose:

To use the acquisition of the k‐space center signal (DC signal) implemented into a Cartesian three‐dimensional (3D) FLASH sequence for retrospective respiratory self‐gating and, thus, for the examination of the whole human lung in high spatial resolution during free breathing.

Materials and Methods:

Volunteer as well as patient measurements were performed under free breathing conditions. The DC signal is acquired after the actual image data acquisition within each excitation of a 3D FLASH sequence. The DC signal is then used to track respiratory motion for retrospective respiratory gating.

Results:

It is shown that the acquisition of the DC signal after the imaging module can be used in a 3D FLASH sequence to extract respiratory motion information for retrospective respiratory self‐gating and allows for shorter echo times (TE) and therefore increased lung parenchyma SNR.

Conclusion:

The acquisition of the DC signal after image signal acquisition allows successful retrospective gating, enabling the reconstruction of high resolution images of the whole human lung under free breathing conditions. J. Magn. Reson. Imaging 2013;37:727–732. © 2012 Wiley Periodicals, Inc.
Customer‐related social stressors and service providers' affective reactions
Authors: Dudenhöffer Sarah , Dormann Christian
Published: September 2012

Previous research has shown that customer‐related social stressors (CSS) have negative effects on service providers' long‐term well‐being. Little is known, however, about short‐term and mid‐term affective stress reactions and reciprocal effects between service providers' affect and CSS. The aim of this study was to expand extant research (i) by analyzing service providers' short‐term (across a day) and mid‐term (across 2 weeks) affective reactions to perceived CSS; (ii) by analyzing intraindividual as well as interindividual effects; and (iii) by investigating reciprocal effects of affective reactions and CSS that may eventually lead to psychosocial cycles. Our study employed a diary design with three measurement occasions per day over five consecutive days and a two‐week panel design using a sample of employees from public service organizations (N = 106). Results showed that CSS elicit changes in service providers' short‐term and mid‐term negative affects. We also found support for reversed effects of service providers' affective reactions on experienced CSS indicating psychosocial cycles between customers and service providers. To prevent escalation, we discuss potential resources. Copyright © 2012 John Wiley & Sons, Ltd.
Gelation Behavior of Bioabsorbable Hydrogels Consisting of Enantiomeric Mixtures of A–B–A Tri‐block Copolymers of Polylactides (A) and Poly(ethylene glycol) (B)
Authors: Lee Chan Woo , Manoshiro Tomoyuki , Hsu Yu‐I , Kimura Yoshiharu
Published: September 2012

A–B–A tri‐block copolymers of poly(L‐lactide) (PLLA: A) and poly(ethylene glycol) (PEG: B) and those of poly(D‐lactide) (PDLA: A) and PEG (B) were prepared and suspended in saline. Mixing suspensions consisting of the enantiomeric copolymers with identical block compositions induced a temperature‐dependent sol‐to‐gel transition. It was found that the composition window of the copolymers that allowed the spontaneous sol–gel transition around body temperature was considerably narrow, being affected by how easily the PLLA and PDLA blocks of the copolymers can form the stereocomplex in the mixed suspensions. The gelation rate and gel strength also depended on the copolymer composition and concentration at a constant gelation temperature of 37 °C.
Polylactide/transition metal ion modified montmorillonite nanocomposite—a critical evaluation of mechanical performance and thermal stability
Authors: K. Prakalathan , Mohanty Smita , Nayak Sanjay K.
Published: September 2012

Polylactide (PLA) nanocomposite was prepared by melt blending of PLA and transition metal ion (TMI) adsorbed montmorillonite (MMT). PLA nanocomposite was characterized for mechanical performance, and the results revealed that the tensile modulus, flexural modulus, and impact strength were increased marginally. The nanocomposite was optimized at 5 wt% of TMI‐modified MMT (TMI‐MMT) loading. Thermogravimetric analysis displayed increase in onset of degradation temperature, and differential scanning calorimetry showed marginal increase in glass transition temperature (Tg) and melting temperature (Tm) in case of PLA nanocomposites, when compared with virgin PLA. The flammability testing of nanocomposites indicated good fire retardance characters. X‐ray diffraction patterns of TMI‐MMT and the corresponding nanocomposites indicated an intercalation of the metal ions into the clay interlayer. Fourier transform infrared spectroscopy analysis indicate formation of [Zn(EDA)2]2+ and [Cu(EDA)2]2+ complexes in the MMT interlayer. Dynamic mechanical analysis shows increase in glass transition temperature (Tg) and storage modulus (E′) in case of PLA nanocomposites reinforced with 5 wt% modified MMT. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers
Preparation and properties of polyester nanocomposites: Effects of mixing
Authors: Rajabian Mahmoud , Piroozfar Hamid , Beheshty Mohammad Hosain
Published: September 2012

A multistep mixing technique to manufacture highly intercalated/exfoliated nanocomposites of layered silicates in thermosetting resins was developed and successfully tested up to 9% nanoparticle content. We investigated the influences of mixing conditions on linear and nonlinear viscoelastic properties of processed clays and polyester suspensions. The effects of shear and mechanical mixing on the state of dispersion and microstructure of the cured nanocomposites were examined by the XRD and TEM techniques. Transient viscosities and linear viscoelastic data for the nanocomposites demonstrated significant enhancement by increasing speed and time of mechanical mixing. The solid state characterization techniques confirm mixed to highly exfoliated and delaminated microstructures were attained by the proposed method. Our observations indicate that the multistage mechanical mixing following a stationary step can be used to produce thermosetting and thermoplastic nanoparticles with the improved properties. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers
Investigation of mechanical and thermodynamic properties of pH‐sensitive poly(N,N‐dimethylaminoethyl methacrylate) hydrogels prepared with different crosslinking agents
Authors: Orakdogen Nermin
Published: September 2012

pH‐sensitive poly(N,N‐dimethylaminoethyl methacrylate) hydrogels were synthesized by free‐radical crosslinking polymerization using two different crosslinking agents; tetraethylene glycol dimethacrylate (TEGMA) and N,N′‐methylenebis(acrylamide) (BAAm). The influence of the polymerization factors such as the type of the crosslinking agent and the gel preparation concentration on the swelling behavior, the gel strength, the effective crosslinking density and the average chain length between the crosslink points for the resulting hydrogels was investigated. The results of the equilibrium swelling measurements in water showed that the linear swelling ratio of the resulting hydrogels increases with increasing gel preparation concentration. The swelling ratio of PDMAEMA hydrogels crosslinked with BAAm is larger than those for hydrogels crosslinked with TEGMA over the entire range of the polymer network concentration. The hydrogels exhibit very sharp pH‐sensitive phase transition in a very narrow range of pH between 7.7 and 8.0. From the mechanical measurements, it was also found that the linear swelling ratio of resulting hydrogels depends on the crosslinking density and also the type of the crosslinker used in the preparation. The resulting hydrogels are thought to be good candidates for pH‐sensitive drug delivery systems. POLYM. ENG. SCI. 2013. © 2012 Society of Plastics Engineers
Simulations and measurements of in‐mold melt flow during the injection molding of polystyrene
Authors: Bress Thomas J. , Dowling David R.
Published: September 2012

Simulations are often used to model polymer flow during injection molding to design molds and select processing parameters. It is difficult to determine the accuracy of these simulations due to a lack of experimentally measured in‐mold velocimetry and melt‐front progression data. This article compares the results from commercial mold‐filling simulation software to experimental data obtained via particle image velocimetry (PIV) in a special optical‐access mold with a rectangular cavity. Moldflow was used to simulate the mold filling by a polystyrene melt in the experimental configuration, and these simulated results are compared to the appropriately averaged time‐varying velocity field measurements. Simulated results for melt‐front progression are also compared with experimentally observed flow fronts. The ratio of the experimentally measured average velocity magnitudes to the simulation magnitudes was found on average to be 0.99 with a standard deviation of 0.25, and the difference in velocity orientations was found to be 0.9° with a standard deviation of 3.2°. The corner area opposite the gate was most problematic for the simulation. The region behind the front also had a relatively high simulation error, though not as severe as that in the corner. POLYM. ENG. SCI. 2013. © 2012 Society of Plastics Engineers
Barriers and facilitators to BRCA genetic counseling among at‐risk Latinas in New York City
Authors: Sussner Katarina M. , Jandorf Lina , Thompson Hayley S. , Valdimarsdottir Heiddis B.
Published: September 2012

Background

Despite underuse of genetic services for hereditary breast and/or ovarian cancer risk among Latinas (including counseling and testing for BRCA mutations), there is little known about the barriers and facilitators to BRCA genetic counseling among this group. It is imperative to first understand factors that may impede Latinas seeking BRCA genetic counseling, as it is considered a prerequisite to testing.

Methods

Quantitative telephone interviews (N = 120) were conducted with at‐risk Latinas in New York City to investigate interest, barriers, and beliefs about BRCA genetic counseling. Statistical analyses examined predictors of intention to undergo BRCA genetic counseling.

Results

Despite moderate levels of awareness, Latinas held largely positive beliefs, attitudes, and knowledge about BRCA genetic counseling. Perceived barriers included logistic concerns (e.g., where to go, cost/health insurance coverage), emotional concerns (e.g., fear, distress), and competing life concerns (e.g., too many other things to worry about, too busy taking care of children or family members). Multivariate results showed that the strongest predictor of intention to undergo BRCA genetic counseling was competing life concerns; Latinas with more competing life concerns were less likely to intend to undergo BRCA genetic counseling (p = 0.0002). Other significant predictors of intention included perceived risk of carrying a BRCA mutation (p = 0.01) and referral by their physician (p = 0.02).

Conclusion

Educational efforts to promote BRCA genetic counseling among at‐risk Latinas and increase referrals by their physicians should incorporate discussion of perceived barriers to counseling, such as competing life concerns that Latinas may need to overcome in order to seek genetic counseling. Copyright © 2012 John Wiley & Sons, Ltd.
Suppressing Hydrogen Evolution by Aqueous Silicon Powder Dispersions by Controlled Silicon Surface Oxidation
Authors: Tichapondwa Shepherd M. , Focke Walter W. , Del Fabbro Olinto , Muller Elmar
Published: September 2012

Aqueous silicon dispersions are used to produce pyrotechnic time delay compositions. The propensity of silicon to react with water and to produce hazardous hydrogen gas must be suppressed. To this end, the effect of air heat treatment temperature on the rate of corrosion of silicon was investigated. It was found that four hour heat treatments at temperatures below 350 °C provided significant passivation. This is attributed to the removal of the hydroxyl groups present on the SiO2 surface scale layer. It was found that thickening the silica layer, by heat treatment at higher temperatures, causes a further reduction in the amount of hydrogen released. However, differential thermal analysis (DTA) studies showed that excessive silicon surface oxidation increased the ignition temperature and reduced the heat release of a near‐stoichiometric silicon‐lead chromate pyrotechnic composition.
Ballistic Modification of Nitramine Propellants with Special Reference to NG‐PE‐PCP‐Based High Energy Propellants
Authors: Pande Shrikant M. , Sadavarte Vaibhav S. , Bhowmik Debdas , Gaikwad Dashrath D. , Singh Haridwar
Published: September 2012

The burning rate pressure relationship is one of the important criteria in the selection of the propellant for particular applications. The pressure exponent (η) plays a significant role in the internal ballistics of rocket motors. Nitramines are known to produce lower burning rates and higher pressure exponent (η) values. Studies on the burning rate and combustion behavior of advanced high‐energy NG/PE‐PCP/AP/Al‐ and NG/PE‐PCP/HMX/AP/Al‐based solid rocket propellants processed by a conventional slurry cast route were carried out. The objective of present study was to understand the effectiveness of various ballistic modifiers viz. iron oxide, copper chromite, lead/copper oxides, and lead salts in combination with carbon black as a catalyst on the burning rate and pressure exponent of these high‐energy propellants. A 7–9 % increase in the burning rates and almost no effect in pressure exponent values of propellant compositions without nitramine were observed. However, in case of nitramine‐based propellants as compared to propellant compositions without nitramines, slight increases of the burning rates were observed. By incorporation of ballistic modifiers, the pressure exponents can be lowered. The changes in the calorimetric values of the formulations by addition of the catalysts were also studied.
Modification of W/O Emulsions by Demilitarized Composition B
Authors: Němec Ondřej , Jungová Marcela , Zeman Svatopluk
Published: September 2012

A series of W/O emulsion explosives containing 30–50 wt‐% of the demilitarized mixture RDX/TNT (Composition B 50/50) was prepared. Detonation velocities and relative explosive strengths of these mixtures were determined and their detonation characteristics were calculated according to the EU standard methods for commercial explosives. Thermal reactivities of the most reactive components of these W/O mixtures were examined by means of differential thermal analysis and outputs were analyzed according to the Kissinger method. The reactivities, expressed as the Ea ⋅ R−1 slopes of the Kissinger relationship, correlate with the squares of the detonation velocities of the corresponding explosive mixtures. It was found that fortification of the W/O emulsions by the demilitarized mixture RDX/TNT allows modification of detonation velocities of the resulting emulsion explosives within relatively broad limits. However, the effect of this admixture on the relative explosive strength is not well defined. Nevertheless, fortification in this sense can give rock‐blasting explosives with a performance on the level of industrial powdered amatols.
Influence of group III and group V partial pressures on the size and density of InGaN quantum dots in MOVPE
Authors: Kadir Abdul , Bellmann Konrad , Simoneit Tino , Pristovsek Markus , Kneissl Michael
Published: September 2012

InGaN quantum dots (QDs) were grown on GaN templates in the Stranski–Krastanov growth mode at 675 °C via metalorganic vapor phase epitaxy (MOVPE). Typically, QDs with overall density of 109 cm−2, an average diameter 50 nm and average height of 7 nm were obtained. A systemic investigation on the influence of group III and group V partial pressure on the size and distribution of the InGaN QDs is reported. A higher growth rate and/or higher V/III ratio increases the mean height and the density of QDs. The distribution of the dots is found to scale with growth rate and the V/III ratio. This is attributed to a reduction in the surface diffusion of adatoms as the results of increase in partial pressure of the precursor in the reactor.
Multivariate probabilistic forecasting using ensemble Bayesian model averaging and copulas
Authors: Möller Annette , Lenkoski Alex , Thorarinsdottir Thordis L.
Published: September 2012

We propose a method for post‐processing an ensemble of multivariate forecasts in order to obtain a joint predictive distribution of weather. Our method utilizes existing univariate post‐processing techniques, in this case ensemble Bayesian model averaging (BMA), to obtain estimated marginal distributions. However, implementing these methods individually offers no information regarding the joint distribution. To correct this, we propose the use of a Gaussian copula, which offers a simple procedure for recovering the dependence that is lost in the estimation of the ensemble BMA marginals. Our method is applied to 48 h forecasts of a set of five weather quantities using the eight‐member University of Washington mesoscale ensemble. We show that our method recovers many well‐understood dependencies between weather quantities and subsequently improves calibration and sharpness over both the raw ensemble and a method which does not incorporate joint distributional information. Copyright © 2012 Royal Meteorological Society
The Slenderness Ratio of the Filter Used in the Process of Liquid Steel Filtration as the Additional Parameter of the Filter Form
Authors: Janiszewski Krystian
Published: September 2012

We propose in this publication the introduction of new, additional definition describing the multiple orifice ceramic filters used in research works on the liquid steel filtrations, calling this the filter slenderness ratio. In order to confirm the theoretical assumptions we have performed a series of the laboratory scale experiments (for the filter slenderness ratio SF1 λ = 1.67 and SF2 λ = 3.34). The influence of the filter slenderness on the filtration process efficiency has been determined through variations in quantities and surface shares of the non‐metallic inclusions in the filtrated steel in relation to the non‐filtered steel. We present also the results of researches on the separating surfaces between the liquid steel and the ceramic filter material, which in form of photos and scanning microscope microanalyses are put together in the publication.
A Procedure for Dimensionality Analyses of Response Data from Various Test Designs
Authors: Zhang Jinming
Published: September 2012

In some popular test designs (including computerized adaptive testing and multistage testing), many item pairs are not administered to any test takers, which may result in some complications during dimensionality analyses. In this paper, a modified DETECT index is proposed in order to perform dimensionality analyses for response data from such designs. It is proven in this paper that under certain conditions, the modified DETECT can successfully find the dimensionality-based partition of items. Furthermore, the modified DETECT index is decomposed into two parts, which can serve as indices of the reliability of results from the DETECT procedure when response data are judged to be multidimensional. A simulation study shows that the modified DETECT can successfully recover the dimensional structure of response data under reasonable specifications. Finally, the modified DETECT procedure is applied to real response data from two-stage tests to demonstrate how to utilize these indices and interpret their values in dimensionality analyses.
Absolute geomagnetic intensity determinations on Formative potsherds (1400–700 BC) from the Oaxaca Valley, Southwestern Mexico
Authors: Pétronille Marie , Goguitchaichvili Avto , Morales Juan , Carvallo Claire , Hueda-Tanabe Yuki
Published: September 2012

New Thellier-Coe archeointensity determinations have been measured on 15 potsherds from the Oaxaca Valley belonging to three of the four Formative Periods (Pre-Classical) of Mesoamerica, spanning 1400–700 BC. Seven of these are considered to be reliable and indicate a geomagnetic field strength of about 30 μT. This value is some 75% of the present geomagnetic field strength but is in agreement with the absolute intensities predicted from global models for this time and location, and consistent with coeval published determinations. These data thus provide significant evidence for the geomagnetic field strength in an area and for a time that was previously poorly constrained, thus providing an important contribution towards establishing a local master curve for the last 3500 yr. When established, such a curve would be a useful dating tool and also enable establishing for field strength correlations with climatic events and civilization evolutions in a region that is particularly strong in archeological and geological features. Such potential is examined for aridity events, although such observations can only be considered tentative at this stage.