bluuebunny/crossref_metadata_2025 huggingface dataset:
Time Zero Value Based on S-Wave Reflection Loss Measurement for Early Age Shrinkage Monitoring of Cementitious Specimens Subjected to Sealed and Unsealed Curing Conditions
Authors: Ong K. C. G. , Chandra L. R.
Published: May 2012

Estimating the time at which to start monitoring early age shrinkage, especially of high performance cementitious materials, can be crucial. Despite numerous studies on early age shrinkage monitoring, there is no general agreement on the time at which early age shrinkage measurements should start (i.e., the “time zero” value [TZV]). The present paper proposes the use of the stiffening time measured via S-wave reflection loss as the TZV for early age shrinkage monitoring of high performance cementitious materials subjected to both sealed and unsealed curing conditions. The results imply that in the case of autogenous or sealed specimens, similar stiffening times occur throughout the specimen depths. In the case of unsealed specimens, however, the results show that the stiffening time might vary with depth depending on the water-to-cementitious ratio used. It is postulated that water redistribution within the specimen, as well as the formation of a “skin layer,” might significantly affect the stiffening time measured in the case of unsealed specimens used for early age drying shrinkage monitoring.
Recent Developments in the Swelling Model of Expansive Clays for Pavement-Heave Calculations
Authors: Livneh Moshe
Published: May 2012

The prediction of pavement heave necessitates knowledge of the swelling-pressure characteristic (the swelling model) of the clay stratum under consideration, data that are usually obtained from laboratory tests on undisturbed clay specimens. It is demonstrated that a general swelling model equation should be employed that predicts the percentage of swell under a given vertical pressure exerted on clay characterized by the following parameters: (a) the liquid limit, (b) the ratio between the in situ moisture content and the plasticity limit, and (c) the in situ dry density. The development of this general equation is described by applying the Excel-solver analysis to 352 local test results, yielding preferable results to those stemming from a previous analysis that utilized the multiple linear regression method. Together with employing the general swelling model, an adjustment for any specific given condition is performed by conducting linear regressions (a simple one and a zero-intercept one) with the local test results and the general swelling model. Finally, the paper outlines guidelines for choosing the most relevant of the three calculated models.
Development of a Robust Stereo-PIV System for 3-D Soil Deformation Measurement
Authors: Yuan Bingxiang , Liu Jinyuan , Chen Wenwu , Xia Kaiwen
Published: May 2012

This paper presents a robust stereo-particle image velocimetry (Stereo-PIV) system developed for three-dimensional (3-D) soil deformation measurement in geotechnical engineering. Also known as digital image correlation, PIV is a popular image processing technique to measure two-dimensional (2-D) fluid velocity in fluid dynamics. The Stereo-PIV technique extends 2-D deformation measurement to 3-D based on a binocular vision model, where two cameras with a well posed geometrical setting, are utilized to image the same object. Although commercial Stereo-PIV systems are available in the market, the applications of this technique are still limited by their high cost and special hardware requirements. This study presents a robust Stereo-PIV system, which utilizes two standard complementary metal–oxide–semiconductor (CMOS) cameras and two open software packages to apply this technique to geotechnical engineering testing.

In order to apply this technique, three steps have to be performed: the first step is the calibration for the system to get the parameters of the two cameras with respect to the region of interest (ROI); the second step is to obtain a series of paired images of the ROI during deformation and calculate the corresponding 2-D displacement fields from these images; and the last step is to construct a 3-D displacement field based on the camera parameters calculated in the first step and the corresponding 2-D displacement vector pairs from the second step.

The developed system is applied in a model test to measure 3-D sand deformation around a laterally loaded pile. The results demonstrate that the system can obtain a reasonable result and can be readily adjusted for more advanced 3-D deformation measurement in geotechnical engineering research.
Evaluation of the Long-Distance Conducted Electrical Weapon XREP®
Authors: Kunz Sebastian N. , Graw Matthias , Peschel Oliver , Grove Nico
Published: May 2012

The TASER® eXtended Range Electronic Projectile (XREP®) is a self-contained, wireless conducted electrical weapon (CEW), which is shot from a 12-gauge shotgun. On impact it delivers short high-voltage, low current energy pulses to temporarily paralyze a person by causing electrical interruption of the body’s normal energy pulses. The present study analyzes the specific weapon-projectile interaction and accuracy of the XREP® live and training rounds at different distances in order to draw conclusions on mission effectiveness. To evaluate the ballistic features of the XREP® ammunition, a high speed camera, photoelectric barrier, reference scale, and coordinate calculator were used. Thirty live rounds (LR) and 35 training rounds (TR) were fired from the TASERX12™ with a customized 18.5 in. barrel. The shooting distances were 4.5 m, 12.1 m, 19.7 m, and 27.4 m. The average velocity of the XREP® TR was v0 71.8 m/s (range 57.6–84.0 m/s) and of the LR 67.0 m/s (range 58.2–73.5 m/s). The standard deviation in accuracy varied within the live rounds vertically from 7.6 mm at a distance of 4.5 m up to 152.1 mm at 27.4 m. The training rounds showed a vertical standard deviation between 7.5 mm (shooting distance 4.5 m) and 222.8 mm (shooting distance 27.4 m). The standard horizontal deviation was noted the highest at 109.4 mm with the TR and 57.7 mm with the LR, both at a shooting distance of 27.4 m. The maximal vertical variation was at a firing distance of 27.4 m; for the TR it was −649.2 mm and for the LR it was −866.7 mm. The XREP® ammunition showed a remarkable high variation in velocity and accuracy. This effect increased disproportionately at shooting distances over 12 m. Furthermore, a significant variation between the training and the live ammunition was noted.
Evaluation of Air Void Distributions of Cement Asphalt Emulsion Mixes Using an X-Ray Computed Tomography Scanner
Authors: Wang Zhenjun , Xiao Jingjing
Published: May 2012

Air void distributions of cement asphalt emulsion mixes are different from those of ordinary asphalt mixes. In order to evaluate a relationship between air voids and aggregate gradations, or binders of the mixes, an x-ray computed tomography (CT) scanner was used to quantify air void ratio, air void area, and air void size in the mixes. A rheometer and scanning electron microscope (SEM) were adopted to analyze viscosity and microstructures of the asphalt emulsion composites. The results indicate that larger air voids are concentrated on the top and the bottom of the mixes. The middle part of the mixes, which constitutes about 60–70 % of its thickness, has a nearly uniform size of air voids. The demarcation of air void ratio between suspended dense structure and framework dense structure is 6.0 %; and that between framework dense structure and framework void structure is 9.0 %. Adoption of ordinary Portland cement and appropriate increase of asphalt emulsion dosages are beneficial to the decrease of the air void ratio. The binders exert little effect on the increase of the air void sizes than the aggregate gradation types do. Benefits of cement addition are to generate hydrates which are helpful to decrease the air void ratios of the mixes.
Estimation of Optimum Compaction Temperature for PMA and WMA Mixtures by Volumetric Property Evaluation
Authors: Lee Moon-Sup , Kim Sungun , Kim Kwang W.
Published: May 2012

The optimum compaction temperature (OCT) is defined as the temperature at which asphalt provides proper viscosity in an asphalt mixture. For normal asphalt, the proper viscosity level has been suggested as 280 ± 30 mm2/s by the American Association of State Highway and Transportation Officials (AASHTO). This suggestion has been effectively utilized in selecting the OCT of normal hot-mix asphalt (HMA). However, because polymer-modified asphalt (PMA) and warm-mix asphalt (WMA) have been used recently, it is difficult to apply this method in general. This study evaluates important volumetric properties (air void ratio and void filled with asphalt) of HMA and WMA mixes. The three binders evaluated included 64-22 and 76-22 for HMA and 70-22 for WMA for dense-graded asphalt mixtures compacted using a Superpave gyratory compactor. The OCT at which the optimum asphalt content could be obtained was determined for the three binders. The OCTs obtained via volumetric property evaluation were 20 °C and 38 °C lower than the values determined via the AASHTO method for PMA and WMA. In mechanical performance comparisons, the mixture compacted at the lower OCT was not inferior to the mixture compacted at a higher OCT. It is therefore concluded that the OCT should be determined based on the volumetric property of mixtures, because compaction is not solely a function of viscosity, especially for PMA and WMA mixtures.
Non-contact and Non-destructive Analysis of the Quality of Phenolic Resin by Near-Infrared Spectroscopy
Authors: Dong Y. , Qu S. Y.
Published: May 2012

The traditional analytical methods used to determine phenolic resin are slow and produce environmentally unfriendly waste. In this work, near-infrared (NIR) spectroscopy has been applied for resin content of phenolic resins. The partial least-squares regression was used to develop the calibration model of the resin content. Eight samples were withdrawn at different time stages for analysis with the proposed quantitative models; the data thus obtained were compared with those provided by reference methods. The maximal predicted error and the standard deviation of the differences were 0.96% and 0.51% for resin content. The results of the paired t test revealed that there was no significant difference between the NIR method and the reference method. NIR spectroscopy is an effective choice for the accurate, expeditious analyzing quality of phenolic resin.
Evaluation of Bentonite-Fly Ash Mix for Its Application in Landfill Liners
Authors: Younus M. M. , Sreedeep S.
Published: May 2012

Compacted landfill liners are required to minimize the migration of harmful contaminants to the surrounding geoenvironment and groundwater. This is mainly achieved by restricting hydraulic conductivity of the compacted liners within a permissible limit of 10−7 cm/s. For geomaterials used in liners, it is important to determine the appropriate range of compaction parameters (water content and dry unit weight) that would ensure hydraulic conductivity and strength characteristics within safe limits. There are not many studies in the literature for specifying such a range for bentonite-fly ash mixes. The addition of cohesionless fly ash would improve the strength and reduce the shrinkage behavior of bentonite but at the same time would increase the hydraulic conductivity. Therefore, it is of utmost importance to determine the ranges of water content and dry unit weight for different bentonite-fly ash mixes that would satisfy the desired ranges of hydraulic conductivity and strength. The objective is to identify the bentonite-fly ash mix that enables maximum use of fly ash, which is advantageous from an environmental perspective. The performance evaluation of different compacted mixes has been done using hydraulic conductivity and unconfined compressive strength as the two reference parameters. The study clearly demonstrates the utility of a bentonite-fly ash mix as a compacted landfill liner. On the basis of the results, it can be noted that up to 70 % by weight of fly ash can be mixed with bentonite for satisfying the requirements of compacted landfill liners.
Constructing an Evaluation Model for Agenting Online Games
Authors: Chueh Hao-En , Chang Che-Wei
Published: May 2012

The purpose of this research is to construct a software evaluation model for online games. Online games require players to link to a computer game manufacturer server. This study applies the grey situation decision making (GSDM) method to measure player degrees of satisfaction from playing online games by addressing their involved psychological needs. This evaluation model can assist a commercial agent in marketing online games. Finally, a case study demonstrates the high satisfaction degree of massive multiple on-line role play games (MMORPGs).
Computer-Controlled Stable Crack Growth as a Reliable and Fast Method to Determine Subcritical Crack Growth
Authors: Özcoban Hüseyin , Fett Theo , Schneider Gerold A.
Published: May 2012

Subcritical crack growth of synthetic fused silica glass is investigated using the single-edge-V-notched-beam method. The measurement was performed in a very stiff four-point bending device, which is equipped with a computer-aided control system. This technique enables several loading cycles of controlled crack growth with one measurement and sample. The control system is based on an online compliance measurement that enables an automatic measurement routine without much operation of the user and without the necessity of the optical observation of the crack. The crack velocity as a function of the applied stress intensity factor was determined by analysing the measured specimen compliance. The presented method allows determining a large number of v–KI curves under identical conditions by measuring only one sample.
Characterizing Profiled Fibers by Multiscale Shape Representations
Authors: Wang RongWu , Tang LiPing , Zeng PeiFeng , Xu BuGao
Published: May 2012

This paper presents a multiscale shape representation approach for measuring the metrological characteristics of profiled fibers. From closed edge chains of a fiber cross section, three points are selected with evenly spaced indices to form a triangle, and the triangle area representation (TAR) is calculated with the determinant of a coordinate array of the three points. The bend direction of two consecutive lines drawn with the three vertices determines the sign of the TAR. Negative and positive TARs, denoted as TARN and TARP, respectively, are used to detect concave and convex segments on the boundary. The size of objects in a TARN or TARP graph reflects the degree of concaveness or convexness. If the index spacing is changed, a series of TARs with different scales can be obtained. Multiscale TARNs and TARPs can be used to recognize the basic shapes of profiled fibers, assess concavity, and detect fiber conglutinations for precise separation.
A Green Purchasing Model by Using ANP and LP Methods
Authors: Lin Chin-Tsai , Chen Chie-Bein , Ting Ying-Chan
Published: May 2012

Economic growth and development bring not only prosperity but also environmental degradation to the earth. In recent years, people have changed their views on traditional supply chain management (SCM). Green purchasing is a current trend in today’s business process management. Green purchasing is a purchasing behavior for buying goods that emphasizes environmental protection. Due to governments’ environmental regulations, such as WEEE and RoHS, directives have been formed and personal consciousness concerning the environment has been raised; therefore, green purchasing is strongly emphasized in SCM. In some high-tech industries, environmental consciousness may dominate the whole purchasing process, since vendors are asked to use environmentally-friendly materials. Customers thereby influence the component providers toward supplying environmentally-friendly products. For instance, in the PC board industry, the customers influence the suppliers’ product manufacturing process with the aim of reducing the negative environmental impact of the materials used by vendors. This study models a green purchasing system by applying the analytic network process (ANP) and linear programming (LP) methods. The ANP provides the solution for green supplier selection and LP resolves the problem of order allocation for each vendor.
Middle School Science and Items of High School Entrance Examination: Examining the Gap in Turkey
Authors: Cepni Salih , Kara Yilmaz , Cil Emine
Published: May 2012

This study presents findings from an analysis of the Turkish Science and Technology Curriculum Guidelines and their alignment to the university entrance examination. The analysis of the Science and Technology Curriculum focused on various related aspects: content areas and learning outcomes in terms of scientific process skills, science technology society and environment, attitudes and values, and cognitive objectives. The level determination examination (LDE) questions, which would allow for enrollment at elite high schools and would inevitably affect middle school students’ university choices, were analyzed in an alignment study regarding the contents of the science and technology program. In order to investigate the relationship between high school science teaching and high school entrance examination, all relevant documents were analyzed by ten science teachers, who have been teaching science and technology courses at middle schools and are concurrently doctoral students at the science education department. The results indicated that the LDE questions and standards were not fully aligned because the first two alignment criteria have a high consistency while a range of knowledge and balance of representation criteria have a low consistency.
Effects of Additives for Warm Mix Asphalt on Performance Grades of Asphalt Binders
Authors: Wu Chaofan , Zeng Menglan
Published: May 2012

Laboratory tests were carried out on a neat asphalt binder and a styrene-butadiene-styrene (SBS) asphalt binder containing Sasobit and Aspha-min as warm mix asphalt (WMA) additives to quantitatively evaluate the effects of the additives on the continuous grading temperatures and grades of asphalt binders in the framework of the performance grading system. Test results and data analyses indicate that the significances of the effects of WMA additives depend on the asphalt binder type, additive type, additive content, and rolling thin film oven (RTFO) aging temperature. The wax-type additive Sasobit has a stiffening effect on the grading temperatures. At typical 3 % content, the upper temperatures can be increased by up to 13.5 °C, the lower temperatures can be increased by up to 6.9 °C, and the intermediate temperatures can be increased by up to 5.0 °C. In the commonly used content range, the zeolite-type additive Aspha-min has little effects on the upper, lower, and intermediate grading temperatures. Although there is a special case, in which the upper grading temperature increase is canceled out by 3.8 °C, the reduction in RTFO aging temperature from 163 °C to 133 °C does not generally result in notable changes in the grading temperatures.
Characterizations of Bamboo Succus And Alkaline Peroxide Mechanical Pulping (APMP) Brightness of Bambusa Chungii
Authors: Song Xueping , Luo Lianxin , Wang Qing , Wang Shuangfei
Published: May 2012

The effects of pre-extraction and of the main components of bamboo succus on the alkaline peroxide mechanical pulping (APMP) pulp brightness of bambusa chungii are investigated by gas chromatography-mass spectroscopy (GC-MS) and infrared spectroscopy analysis. The results show that the chromophore and auxochrome groups of unsaturated bonds are plentiful in the bamboo succus. The contents of methyl benzene, xylene, and hydroquinone (75.88%, 0.98%, and 0.41%, respectively) are high in bamboo succus, and the three materials have great effect on APMP brightness, especially the hydroquinone. For the APMP with the bamboo chip by 60% ethanol pre-extracting, the brightness of unbleached pulp is higher about 5% ISO, the brightness of bleached pulp is higher about 4.2% ISO, and the p.c value is lower. If methyl benzene, xylene, and hydroquinone are added into the pulp, the CH3, CH2, acetyl, conjugated carbonyl C = O and C-O can be increased. The XPS analysis indicates that on the surface of pulp, the content of non-carbohydrate and the C = O, O - C - O and O = C - O increases, but the content of carbohydrate decreases if such additives are added.
Evaluating the Entry Mode for Taiwan Insurance Companies by Using AHP Sensitivity
Authors: Ho Elaine , Lin Chun Yueh
Published: May 2012

This work presents an evaluation model that adopts several important criteria, enabling the Taiwan insurance industry to enter into the Chinese market in the most appropriate way. Major criteria weights are analyzed using an analytic hierarchy process (AHP) and sensitivity analysis. The results of the analysis indicate that the proposed evaluation model enables the Taiwan insurance industry to enter into the Chinese market more objectively by allowing companies to deploy effectively. Importantly, the proposed model can provide Taiwan’s insurance industry accreditation policy with reference material, making it highly applicable for academic and commercial purposes.
Sam Cooke as Pop Album Artist—A Reinvention in Three Songs
Authors: Burford Mark
Published: May 2012

Though African American singer, songwriter, and entrepreneur Sam Cooke (1931–1964) is commonly celebrated as a pioneering soul singer, the preponderance of Cooke recordings suggesting to many critics a “white” middle-of-the-road pop sound has troubled this reception. From June 1957 until the end of 1959, Cooke recorded for the independent label Keen Records, where he charted a course for realizing his professional and socioeconomic aspirations, including his determination to harness the prestige attached to the long-playing album and the “album artist.” This article explores relationships between the repertory, performances, and production on three Keen album tracks: “Danny Boy,” “My Foolish Heart,” and “I've Got a Right to Sing the Blues.” These recordings reveal Cooke's seldom-noted proximity to contemporaneous figures and concerns: “Irish tenor” Morton Downey, who built a career on the fluidity between ethnic identity and pop's transparent “whiteness”; Billy Eckstine, who struggled to navigate the racial and sexual politics of the pop balladeer; and the black studio musicians whose campaign for employment equity in 1950s Los Angeles found resonance with Cooke's vision. Taking Cooke's endeavor seriously positions us to assess freshly Cooke's skills as a vocalist, the processes through which “pop” becomes racialized as white, and intractable methodological challenges in black music studies.
Predictors of morbidity and mortality in acromegaly: an Italian survey
Authors: Arosio M , Reimondo G , Malchiodi E , Berchialla P , Borraccino A , De Marinis L , Pivonello R , Grottoli S , Losa M , Cannavò S , Minuto F , Montini M , Bondanelli M , De Menis E , Martini C , Angeletti G , Velardo A , Peri A , Faustini-Fustini M , Tita P , Pigliaru F , Borretta G , Scaroni C , Bazzoni N , Bianchi A , Appetecchia M , Cavagnini F , Lombardi G , Ghigo E , Beck-Peccoz P , Colao A , Terzolo M , _ _
Published: May 2012

Objective

To describe demographic and hormonal characteristics, comorbidities (diabetes mellitus and hypertension), therapeutic procedures and their effectiveness, as well as predictors of morbidity and mortality in a nationwide survey of Italian acromegalic patients.

Design

Retrospective multicenter epidemiological study endorsed by the Italian Society of Endocrinology and performed in 24 tertiary referral Italian centers. The mean follow-up time was 120 months.

Results

A total of 1512 patients, 41% male, mean age: 45±13 years, mean GH: 31±37 μg/l, IGF1: 744±318 ng/ml, were included. Diabetes mellitus was reported in 16% of cases and hypertension in 33%. Older age and higher IGF1 levels at diagnosis were significant predictors of diabetes and hypertension. At the last follow-up, 65% of patients had a controlled disease, of whom 55% were off medical therapy. Observed deaths were 61, with a standardized mortality ratio of 1.13 95% (confidence interval (CI): 0.87–1.46). Mortality was significantly higher in the patients with persistently active disease (1.93; 95% CI: 1.34–2.70). Main causes of death were vascular diseases and malignancies with similar prevalence. A multivariate analysis showed that older age, higher GH at the last follow-up, higher IGF1 levels at diagnosis, malignancy, and radiotherapy were independent predictors of mortality.

Conclusions

Pretreatment IGF1 levels are important predictors of morbidity and mortality in acromegaly. The full hormonal control of the disease, nowadays reached in the majority of patients with modern management, reduces greatly the disease-related mortality.
A Coalescent Model for Genotype Imputation
Authors: Jewett Ethan M , Zawistowski Matthew , Rosenberg Noah A , Zöllner Sebastian
Published: May 2012

The potential for imputed genotypes to enhance an analysis of genetic data depends largely on the accuracy of imputation, which in turn depends on properties of the reference panel of template haplotypes used to perform the imputation. To provide a basis for exploring how properties of the reference panel affect imputation accuracy theoretically rather than with computationally intensive imputation experiments, we introduce a coalescent model that considers imputation accuracy in terms of population-genetic parameters. Our model allows us to investigate sampling designs in the frequently occurring scenario in which imputation targets and templates are sampled from different populations. In particular, we derive expressions for expected imputation accuracy as a function of reference panel size and divergence time between the reference and target populations. We find that a modestly sized “internal” reference panel from the same population as a target haplotype yields, on average, greater imputation accuracy than a larger “external” panel from a different population, even if the divergence time between the two populations is small. The improvement in accuracy for the internal panel increases with increasing divergence time between the target and reference populations. Thus, in humans, our model predicts that imputation accuracy can be improved by generating small population-specific custom reference panels to augment existing collections such as those of the HapMap or 1000 Genomes Projects. Our approach can be extended to understand additional factors that affect imputation accuracy in complex population-genetic settings, and the results can ultimately facilitate improvements in imputation study designs.
The Paf1 Complex Subunit Rtf1 Buffers Cells Against the Toxic Effects of [PSI+] and Defects in Rkr1-Dependent Protein Quality Control in Saccharomyces cerevisiae
Authors: Klucevsek Kristin M , Braun Mary A , Arndt Karen M
Published: May 2012

The Rtf1 subunit of the Paf1 complex is required for specific histone modifications, including histone H2B lysine 123 monoubiquitylation. In Saccharomyces cerevisiae, deletion of RTF1 is lethal in the absence of Rkr1, a ubiquitin-protein ligase involved in the destruction of nonstop proteins, which arise from mRNAs lacking stop codons or translational readthrough into the poly(A) tail. We performed a transposon-based mutagenesis screen to identify suppressors of rtf1Δ rkr1Δ lethality and found that a mutation in the gene encoding the protein chaperone Hsp104 rescued viability. Hsp104 plays a role in prion propagation, including the maintenance of [PSI+], which contributes to the synthesis of nonstop proteins. We demonstrate that rtf1Δ and rkr1Δ are synthetically lethal only in the presence of [PSI+]. The deletion, inactivation, and overexpression of HSP104 or the overexpression of prion-encoding genes URE2 and LSM4 clear [PSI+] and rescue rtf1Δ rkr1Δ lethality. In addition, the presence of [PSI+] decreases the fitness of rkr1Δ strains. We investigated whether the loss of RTF1 exacerbates an overload in nonstop proteins in rkr1Δ [PSI+] strains but, using reporter plasmids, found that rtf1Δ decreases nonstop protein levels, indicating that excess nonstop proteins may not be the cause of synthetic lethality. Instead, our data suggest that the loss of Rtf1-dependent histone modifications increases the burden on quality control pathways in cells lacking Rkr1 and containing [PSI+].
Quantified Comparison of Ordering in Self-Assembled Block Copolymer Films of Different Molecular Weights by Image Analysis Method
Authors: Kehoe Timothy , Kehagias Nikolaos , Khunsin Worawut , Borah Dipu , Morris Michael , Sotomayor Torres Clivia M.
Published: May 2012

The order in self-assembled block copolymer films with hexagonal structure is compared using an image analysis method and images taken by scanning electron microscopy and atomic force microscopy. The coordinates of the centres of cylindrical elements in the assembled array are assigned using image analysis software. The method is then used to calculate the amount of elements that symmetrically overlap with another element when mapped through an origin point. Order is compared based on a single numerical value which is dependent on radial distance from the origin and the overlap tolerance value that is assigned. Samples of PS-b-PEO diblock copolymer with a range of molecular weights are compared, and it is found that the degree of ordering achieved is not related to the size of the molecule.
Fabrication of Titanium Oxide Film with high crystallinity by the New Electrochemical Techniques
Authors: Ishizaki Hiroki , Ito Seishiro
Published: May 2012

TiO2 films with poly crystal were electrodeposited on conductive substrate (NESA glass, approximately 10Ω/□, Asahi glass Co. Ltd.) from the titanium potassium oxalate dehydrate aqueous solution containing hydroxylamine adjusted pH 9 with KOH aq. at 333k. The peak corresponded to Ti3+ion into these TiO2 film was not observed by using X-ray photoelectron spectroscopy (XPS). The photocatalysis of TiO2 film increased with a decrease of cathodic potential. In particular, TiO2 film obtained at cathodic potential of -1.3V, had the higher photocatalysis than that of other potential.
Correlation between Filament Distribution and Resistive Switching Property in Binary-Transition-Metal-Oxide Based Resistive Random Access Memory.
Authors: Tanaka H. , Kinoshita K. , Yoshihara M. , Kishida S.
Published: May 2012

Large variation in basic memory properties is a serious issue that hinders the practical use of ReRAM. This study revealed that one of the main factors causing variation is the presence of multiple filaments which have distinct set voltages in each memory cell. An operating filament switches to another filament having the smallest set voltage at each instant of switching. We propose a resistive switching model that takes the presence of multiple filaments into consideration. A Monte Carlo simulation based on the resistive switching model reproduces the set voltage distribution. Improvement of accuracy of the simulation can be also expected considering the fact that Vset increases at a certain probability at each instant of set switching.
Gold-Doped Oxide Nanocomposites Prepared by Two Solution Methods and Their Gas-Sensing Response
Authors: Wang Chien-Tsung , Chen Huan-Yu , Chen Yu-Chung
Published: May 2012

Gold species on an oxide support possess variable electronic structures via charge transition so as to increase their chemical redox activity. They are also viably promising for use to enhance gas-sensing response when being exploited in a solid state gas sensor. The synthesis method of the gold-loaded materials plays a crucial role in the functionality. In this paper, we report two types of gold/tin oxide based nanopowders prepared by co-precipitation method and by deposition-precipitation method, respectively. They were evaluated as sensing elements in a semiconductor carbon monoxide (CO) gas sensor. Effects of the material type and CO concentration on sensor response were investigated. Their structural characterizations were done by X-ray photoelectron spectroscopy, X-ray diffraction and transmission electron microscopy. Results demonstrate the surface gold species effective to facilitate CO oxidation in gas atmosphere and promote low-temperature sensor performance.
Palliative Care in Advanced Cancer Patients: How and When? And Where?
Authors: Porzio Giampiero , Mercadante Sebastiano , Aielli Federica , Verna Lucilla , Ficorella Corrado
Published: May 2012

A study by Bruera et al. published in a recent issue of The Oncologist is discussed.
Thermal elongation of sandwich panels
Authors: Davies J. Michael
Published: May 2012

Sandwich cladding panels with two thin metal faces separated by a lightweight core are well-established cladding products. There have been several instances recently in which the thermal elongation or contraction of sandwich panels has been cited as a possible cause of leakage or local damage in a roof. Historically, the industry has always designed sandwich panels for proper combinations of conventional loading together with a temperature gradient across the panel. This temperature gradient gives rise to ‘thermal bow' which can cause stresses of the same order of magnitude as those from wind or snow load. As a result of this, designers have generally dismissed longitudinal thermal movements from consideration because it is argued that they are taken out by ‘thermal bow' rather than by linear expansion or contraction. Conversely, it is not unusual for roofing and cladding ‘experts' to argue either that thermal bow has little influence on longitudinal thermal movements or that, although it may help in the summer case, it can be of no benefit when the panels try to contract in winter. Surprisingly, there does not appear to have been any previous attempt to determine the actual thermal expansion or contraction of multi-span sandwich panels and appropriate calculation procedures are described for the first time in this study. Perhaps unsurprisingly, it transpires that neither side is correct. Thermal bow results in a significant reduction of longitudinal temperature movements, but it does not eliminate them completely. The formal calculations are not trivial, but it is possible to make a relatively simple estimate of the movements arising in a long panel which has several approximately equal spans.
Shear strength model for fibre reinforced polymer shear reinforced concrete beams
Authors: Kang Su-Min , Choi Kyoung-Kyu
Published: May 2012

In the present study, an integrated shear design method was developed to evaluate the shear strength of concrete beams with and without fibre reinforced polymer shear reinforcement. The contributions of fibre reinforced polymer steel re-bars, and concrete to shear strength were defined separately. The shear strength contribution of a concrete cross-section was defined by the strain-based shear strength model developed in the previous study. In the model, the shear strength of the concrete cross-section was evaluated based on the material failure criteria of the concrete subjected to the compressive normal stress and shear stress. In this study, the ratio of FRP effective strain to ultimate strain needed to evaluate the fibre reinforced polymer shear strength contribution was defined based on the existing test results. The proposed strength model was verified by comparing its prediction to prior test results. In the comparison, it was found that the proposed method accurately predicted the shear strengths of the test specimens for both FRP shear reinforced and unreinforced concrete beams.
Making a stand: five centuries of population growth in colonizing populations ofPinus ponderosa
Authors: Lesser Mark R. , Jackson Stephen T.
Published: May 2012

The processes underlying the development of new populations are important for understanding how species colonize new territory and form viable long‐term populations. Life‐history‐mediated processes such as Allee effects and dispersal capability may interact with climate variability and site‐specific factors to govern population success and failure over extended time frames. We studied four disjunct populations of ponderosa pine in the Bighorn Basin of north‐central Wyoming to examine population growth spanning more than five centuries. The study populations are separated from continuous ponderosa pine forest by distances ranging from 15 to >100 km. Strong evidence indicates that the initial colonizing individuals are still present, yielding a nearly complete record of population history. All trees in each population were aged using dendroecological techniques. The populations were all founded between 1530 and 1655 cal yr CE. All show logistic growth patterns, with initial exponential growth followed by a slowing during the mid to late 20th century. Initial population growth was slower than expectations from a logistic regression model at all four populations, but increased during the mid‐18th century. Initial lags in population growth may have been due to strong Allee effects. A combination of overcoming Allee effects and a transition to favorable climate conditions may have facilitated a mid‐18th century pulse in population growth rate.
The age of island‐like habitats impacts habitat specialist species richness
Authors: Horsák Michal , Hájek Michal , Spitale Daniel , Hájková Petra , Dítě Daniel , Nekola Jeffrey C.
Published: May 2012

While the effects of contemporaneous local environment on species richness have been repeatedly documented, much less is known about historical effects, especially over large temporal scales. Using fen sites in the Western Carpathian Mountains with known radiocarbon‐dated ages spanning Late Glacial to modern times (16 975–270 cal years before 2008), we have compiled richness data from the same plots for three groups of taxa with contrasting dispersal modes: (1) vascular plants, which have macroscopic propagules possessing variable, but rather low, dispersal abilities; (2) bryophytes, which have microscopic propagules that are readily transported long distances by air; and (3) terrestrial and freshwater mollusks, which have macroscopic individuals with slow active migration rates, but which also often possess high passive dispersal abilities. Using path analysis we tested the relationships between species richness and habitat age, area, isolation, and altitude for these groups. When only matrix‐derived taxa were considered, no significant positive relation was noted between species richness and habitat size or age. When only calcareous‐fen specialists were considered, however, habitat age was found to significantly affect vascular plant richness and, marginally, also bryophyte richness, whereas mollusk richness was significantly affected by habitat area. These results suggest that in inland insular systems only habitat specialist (i.e., interpatch disperser and/or relict species) richness is influenced by habitat age and/or area, with habitat age becoming more important as species dispersal ability decreases.
The influence of host diversity and composition on epidemiological patterns at multiple spatial scales
Authors: Moore Sean M. , Borer Elizabeth T.
Published: May 2012

Spatial patterns of pathogen prevalence are determined by ecological processes acting across multiple spatial scales. Host–pathogen interactions are influenced by community composition, landscape structure, and environmental factors. Explaining prevalence patterns requires an understanding of how local determinants of infection, such as community composition, are mediated by landscape characteristics and regional‐scale environmental drivers. Here we investigate the role of local community interactions and the effects of landscape structure on the dynamics of barley and cereal yellow dwarf viruses (B/CYDV) in the open meadows of the Cascade Mountains of Oregon. B/CYDV is an aphid‐transmitted, generalist pathogen of over 100 wild and cultivated grass species. We used variance components analysis and model selection techniques to partition the sources of variation in B/CYDV prevalence and to determine which abiotic and biotic factors influence host–pathogen interactions in a Cascades meadow system. B/CYDV prevalence in Cascades meadows varied by host species identity, with a significantly higher proportion of infectedFestuca idahoensisindividuals thanElymus glaucusorBromus carinatus. Although there was significant variation in prevalence among host species and among meadows in the same meadow complex, there was no evidence of any significant variation in prevalence among different meadow complexes at a larger spatial scale. Variation in prevalence among meadows was primarily associated with the local community context (host identity, the relative abundance of different host species, and host species richness) and the physical landscape attributes of the meadow. These results highlight the importance of local host community composition, mediated by landscape characteristics such as meadow aspect, as a determinant of the spatial pattern of infection of a multi‐host pathogen.
Habitat patch shape, not corridors, determines herbivory and fruit production of an annual plant
Authors: Evans Daniel M. , Turley Nash E. , Levey Douglas J. , Tewksbury Joshua J.
Published: May 2012

Habitat corridors confer many conservation benefits by increasing movement of organisms between habitat patches, but the benefits for some species may exact costs for others. For example, corridors may increase the abundance of consumers in a habitat to the detriment of the species they consume. In this study we assessed the impact of corridors on insect herbivory of a native plant,Solanum americanum, in large‐scale, experimentally fragmented landscapes. We quantified leaf herbivory and assessed fruit production as a proxy for plant fitness. We also conducted field surveys of grasshoppers (Orthoptera), a group of abundant, generalist herbivores that feed onS. americanum, and we used exclosure cages to explicitly link grasshopper herbivory to fruit production of individualS. americanum. The presence of corridors did not increase herbivory or decrease plant fruit production. Likewise, corridors did not increase grasshopper abundance. Instead, patches in our landscapes with the least amount of edge habitat and the greatest amount of warmer “core” area had the highest levels of herbivory, the largest cost to plant fruit production as a result of herbivory, and the most grasshoppers. Thus habitat quality, governed by patch shape, can be more important than connectivity for determining levels of herbivory and the impact of herbivory on plant fitness in fragmented landscapes.
Genetic diversity increases population productivity in a sessile marine invertebrate
Authors: Aguirre J. David , Marshall Dustin J.
Published: May 2012

Reductions in genetic diversity can have widespread ecological consequences: populations with higher genetic diversity are more stable, productive and resistant to disturbance or disease than populations with lower genetic diversity. These ecological effects of genetic diversity differ from the more familiar evolutionary consequences of depleting genetic diversity, because ecological effects manifest within a single generation. If common, genetic diversity effects have the potential to change the way we view and manage populations, but our understanding of these effects is far from complete, and the role of genetic diversity in sexually reproducing animals remains unclear. Here, we examined the effects of genetic diversity in a sexually reproducing marine invertebrate in the field. We manipulated the genetic diversity of experimental populations and then measured individual survival, growth, and fecundity, as well as the size of offspring produced by individuals in high and low genetic diversity populations. Overall, we found greater genetic diversity increased performance across all metrics, and that complementarity effects drove the increased productivity of our high‐diversity populations. Our results show that differences in genetic diversity among populations can have pervasive effects on population productivity within remarkably short periods of time.
Vitamin D Deficiency: A Cause of Periradicular Bone Loss
Authors: Sharma Praveen , Weston Paul , Chapple Iain
Published: May 2012

Introduction: The classic manifestations of vitamin D deficiency include rickets and osteomalacia. Here we demonstrate a case of vitamin D deficiency presenting as radiologic bone loss around the apical and marginal periodontal tissues, consistent with periapical cemental dysplasia. Potential mechanisms for this are explored and the importance of dentists in managing such cases is discussed.

Case Presentation: An 18‐year‐old female patient was referred with marginal periodontal bone loss. Radiology revealed marginal bone loss and multiple asymptomatic periapical radiolucencies associated with teeth that responded positively to pulp testing. The patient was of Southern Asian descent, wore a headscarf and occlusive clothing for cultural reasons, and was visibly malnourished, reporting a poor diet. A diagnosis of severe vitamin D deficiency was confirmed by serum biochemistry. The patient underwent vitamin D supplementation, after which the radiolucent areas resolved.

Conclusions: The prevalence of vitamin D deficiency in patients in the northern hemisphere is under‐recognized, especially in certain ethnic populations. Vitamin D deficiency may contribute (directly or indirectly) to periodontal bone loss either marginally or apically, in susceptible patients. Dental health professionals are well placed to diagnose vitamin deficiencies, including vitamin D, and advise patients on the benefits of a healthy diet and appropriate sun exposure.
The Use of Preoperative Epoetin-α in Revision Hip Arthroplasty
Authors: Delasotta Lawrence A , Rangavajjula Ashwin , Frank Michael L , Blair Jamie , Orozco Fabio , Ong Alvin
Published: May 2012

Purpose:

To evaluate the efficacy of preoperative epoetin-α on the revision hip arthroplasty patient. We hypothesized that epoetin-α will reduce blood transfusion. A pertinent review of the literature is provided.

Methods:

Forty-six patients were retrospectively reviewed. Sixteen patients received epoetin-α. Patients were case matched by age, preoperative hemoglobin, surgery, gender, and BMI. The clinical triggers for blood transfusion during or after the procedure were determined based on peri- and postoperative hemoglobin levels, ASA score, and/or clinical symptoms consistent with anemia. Blood salvage was not used.

Results:

Blood transfusion and length of stay were decreased in the epoetin-α group. Hemoglobin in the intervention group increased from 12.0 to 14.5, preoperatively. Patients who received epoetin-α were 0.78 (RR=0.225) times as likely to receive a transfusion. Number Needed to Treat (NNT) to avoid one allogeneic transfusion was 1.84. Age, Gender, BMI, ASA, total and hidden blood loss, preoperative Iron supplements, preop Hct, preop PLT, PT, PTT, and INR were similar. One (6.0%) patient developed an uncomplicated deep venous thrombosis in the intervention group.

Conclusions:

The mildly anemic revision hip arthroplasty patient is at increased risk for transfusion. Epoetin-α increased preoperative hemoglobin counts and reduced transfusions in this study; it also decreased patient length of hospital stay likely allowing for an earlier readiness to resume normal activities and/or meet short-term milestones. A randomized study to evaluate the direct and indirect costs of such a treatment methodology in the mildly anemic revision patient may be warranted.