bluuebunny/crossref_metadata_2025 huggingface dataset:
Structural and functional diversification of HORMA domain‐containing proteins
Authors: ZHANG Luo‐Yan , ZHU Zhu , YANG Ji
Published: January 2015

HORMA domain‐containing proteins play important roles in cell cycle regulation and DNA repair, acting as adaptors to recruit other proteins. Although containing the conserved HORMA domain in structure, different types of HORMA proteins have diverged significantly in function. The mechanisms underlying the evolution and functional diversification of HORMA proteins remain unclear. Here we conduct an integrative approach, combining sequence, structural, gene coexpression and protein–protein interaction data, to trace the structural and functional evolution of HORMA proteins. Comparative sequence and structure analysis revealed that variations in both amino acid sequence and domain composition contributed to the functional diversification of different HORMA domain‐containing proteins. Multiple amino acid substitutions at the C‐terminal region promoted the functional divergence between MAD2 and REV7 by facilitating interaction with different partners. The emergence of the HOP1CTD domain contributed to the function of HOP1 as a meiosis‐specific structural component of the lateral elements of the synaptonemal complex. Additionally, different types of HORMA proteins were recruited into different functional modules in the genetic network while functioning distinctly.
Transforming Structural Breakdown into Sensory Perception of Texture
Authors: Foegeding E. Allen , Vinyard Christopher J. , Essick Gregory , Guest Steve , Campbell Caroline
Published: January 2015

Food structure research has historically focused on building and stabilizing specific structural elements. Precise execution of unit operations in food processing is required to ensure consistent structure formation, but does not explain why a particular structure is desirable. The pattern by which food structure breaks down during oral processing, generating texture, flavor and taste, determines the acceptability of a food. However, breakdown patterns and textural perception associated with desirable food qualities are not well understood. Food materials are classified based on their physical state (liquids, semisolids or solids) and interactions with surfaces (adhesive or nonadhesive). Physical and chemical processes during oral processing are used to further characterize each food category. Typical processes include particle reduction, dissolution, hydration, removal of food from oral surface and bolus formation. This review presents a framework for classifying food materials and material transformations during oral processing in order to identify their contributions to texture perception.

Practical Applications

There is a constant desire to reformulate or modify foods based on economic, sustainability, health and dietary considerations. One goal of a reformulated food is to change the composition but cause no significant changes in flavor, taste and textural properties associated with desirability. An alternative goal is to modulate a specific textural element to make the food more acceptable to a target population (e.g., those with compromised chewing ability). Both goals require an understanding of the fundamental elements that cause specific textural properties. This manuscript presents an overview of how the breakdown of food structure during oral processing generates the cognition of textural properties. Once textural properties are understood based on specific elements of structural transitions, this will allow for development of textures for specific market segments (e.g., vegan, gluten free or swallowing disorders) as well as the ability to control nutrient bioavailability and flavor release.
Enzymatic Modification to Stabilize the Fermented Milk Drink, Doogh
Authors: Shirkhani Mohammad , Madadlou Ashkan , Khosrowshahi Asghar
Published: January 2015

In this study, the effect of enzyme transglutaminase on physicochemical and sensory characteristics of the fermented milk drink, Doogh, was investigated. Also, the influence of two preparation methods, i.e., water addition to yoghurt as a common method and fermentation of diluted milk as an alternative, was studied. The enzyme was applied into the skim milk either before or after pasteurization followed by thermal inactivation. Doogh prepared by fermentation of diluted milk resulted in more stable products with less phase separation. Enzymatic treatment after pasteurization of milk followed by water addition and fermentation yielded the least phase separation during storage. Doogh stability was associated with improvement of other physicochemical properties of the product such as increase in the apparent viscosity, storage modulus and uniformity of particles accompanied by whiter appearance and finer meshed network and smaller pores in their microscopic structure. Enzymatic treatment resulted in lower sensory scores evaluated by panelists.

Practical Applications

Fermented milk drinks, including the Iranian Doogh, are healthy and refreshing beverages. Serum separation is the main textural defect in these types of products. Transglutaminase, a cross‐linking enzyme, can be used to improve the physicochemical characteristics of Doogh. Application of transglutaminase after pasteurization in water‐added milk as an alteration in industrial processing causes more stable product, less energy consumption especially at the cooling step and faster preparation. In Doogh manufacturing, transglutaminase must be inactive to prevent forming protein clots during storage; therefore, transglutaminase cannot be added simultaneously with starter culture in this case.
Back Extrusion Rheology for Evaluating the Transitional Effects of High Pressure Processing of Egg Components
Authors: Ramaswamy Hosahalli S. , Singh Ajaypal , Sharma Monica
Published: January 2015

In this study, a back extrusion concept was used to evaluate the rheological properties of egg components treated by high pressure processing. Rheological properties, such as viscosity index (ɳ) and apparent elasticity (Ea) of egg components, were evaluated using a central composite design with three independent variables included at five levels. The variables used were high pressure (350−550 MPa), treatment time (10–20 min) and temperature (15−35C). Apparent viscosity was also evaluated using a conventional rheology, using a parallel plate rotational viscometer. Viscosity index and apparent elasticity of various egg components were found to increase significantly (P < 0.05) with an increase in treatment intensity. A relationship between apparent viscosity (rheological) and viscosity index (textural properties) was established. It revealed positive correlations for all egg components (egg white, egg yolk and whole liquid egg) with R2 values higher than 0.95.

Practical Applications

Textural/rheological characteristics play a significant role in determining the functional properties of whole liquid egg, egg white or egg yolk. Liquid foods are usually characterized by conventional viscometry and solid foods by their texture. The transition between liquid and solid covering the semi‐solid consistency poses measurement problems for both techniques. Back extrusion rheology can be used to bridge the gap between the two. High pressure processing allows the liquid egg components to be transformed from liquid to a gel‐like to a solid consistency, depending on the applied pressure level, temperature and time. Hence, back extrusion rheology is ideally suitable for studying texture formation in egg products during high pressure processing.
Lathyrus hirsutus (Caley Pea) Intoxication in a Herd of Horses
Authors: Holbrook T.C. , Gilliam L.L. , Stein F.P. , Morgan S.E. , Avery A.L. , Confer A.W. , Panciera R.J.
Published: January 2015

Background

Caley Pea (Lathyrus hirsutus) is potentially toxic to horses, but large case series are not reported.

Objectives

To describe the clinical signs of horses intoxicated with Lathyrus hirsutus and speculate on the neuroanatomical lesion localization and pathogenesis based upon the observed clinical signs.

Animals

Twenty‐two of 25 horses ranging in age from 6 to 34 months were affected. Five affected horses were presented to the OSUCHVS for evaluation and treatment after having been attended at the ranch by a local veterinarian (ALA). An additional horse that had been euthanized was also presented for necropsy.

Methods

A case series is presented. Diagnostic evaluation included: physical examination, complete blood count, serum biochemistry, CSF analysis, EMG, ERG, upper airway endoscopy, muscle biopsy, and serum vitamin E analysis. The grain ration consumed by the affected horses was analyzed for ionophores and cultured for fungi: the hay was examined for toxic plants.

Results

Bermuda grass hay consumed by the horses contained large quantities of mature Lathyrus hirsutus. Acute clinical signs conform to earlier descriptions of Lathyrus hirsutus intoxication in cattle. Residual neurologic signs were characterized by incoordination in the rhythmicity of multiple gaits. Evidence of mild neurogenic muscle atrophy was recognized in 1 of 5 horses biopsied.

Conclusions and Clinical Importance

Caley Pea intoxication may occur within days of seed pod consumption. The neurologic signs are unique and suggest involvement of the upper motor neuron system and regions of the spinal cord influencing voluntary motor movement. Drought conditions during plant growth may increase the risk of toxicosis.
Echocardiographic Evaluation of Myocardial Changes Observed After Closure of Patent Ductus Arteriosus in Dogs
Authors: Hamabe L. , Kim S. , Yoshiyuki R. , Fukayama T. , Nakata T.M. , Fukushima R. , Tanaka R.
Published: January 2015

Background

Closure of PDA can be associated with echocardiographic changes including deterioration of LV systolic function. Although PDA is commonly encountered in dogs, few comprehensive reports of echocardiographic changes in dogs with PDA closure are available.

Objectives

To evaluate the short‐term echocardiographic changes observed after PDA closure in dogs using strain analysis.

Animals

Seventeen client‐owned dogs with left‐to‐right PDA.

Methods

Echocardiographic evaluations, including standard echocardiography and two‐dimensional tissue tracking (2DTT), were performed before and within 3 days of PDA closure.

Results

Preclosure examination showed LV and left atrial dilatation indicating volume overload as a result of PDA. Closure of PDA resulted in significant reduction of LVIDd (<.0001) and LA/Ao (0.01) without change in LVIDs, suggestive of decreased preload. Postclosure LV systolic dysfunction was observed with significant decreased in FS (<.0001) and strain values (P = .0039 for radial strains, P = .0005 for circumferential strains). Additionally, significant LV dyssynchrony (P = .0162) was observed after closure of PDA.

Conclusions and Clinical Importance

Closure of PDA resulted in decreased preload as a result of alleviation of LV volume overload, which in turn caused transient deterioration of LV systolic function. Additionally, this study demonstrated that strain analysis is load dependent. Therefore, care should be taken when interpreting strain measurements as an indicator of LV systolic function.
Lethal and sub‐lethal effects of faecal deltamethrin residues on dung‐feeding insects
Authors: MANN C. M. , BARNES S. , OFFER B. , WALL R.
Published: January 2015

Endectocides administered to livestock to facilitate pest and parasite control may be excreted in the faeces at concentrations that are toxic to coprophagous insects, including species of ecological importance. Although much research has focused on the effects of macrocyclic lactones, relatively less attention has been given to any similar impacts of the widely used pyrethroid insecticides. Here, the effects of faecal residues of the pyrethroid deltamethrin after application to Holstein–Friesian cattle in a proprietary pour‐on formulation are examined. Freshly dropped dung was collected 1, 3, 5 and 7 days after treatment and from an untreated control group. In laboratory bioasssays, female Lucilia sericata (Diptera: Calliphoridae) blow flies matured significantly smaller egg batches and had a lower percentage of eggs hatch after feeding on dung collected for up to 5 days after treatment, compared with flies feeding on dung from untreated cattle. In the field, artificial dung pats were constructed from the collected dung and left on pastureland for 7 days before being retrieved and searched for insects. Significantly more adult Diptera emerged from the faeces of untreated cattle than from the dung of treated cattle collected on days 1 and 3 after treatment. Adult Coleoptera were found in lower numbers in the dung of treated animals compared with control dung, suggesting a repellent effect. The results indicate that deltamethrin residues in cattle faeces have a range of lethal and sub‐lethal effects on dung‐feeding insects for up to a week after treatment, but that the precise duration and nature of toxicity varies depending on the sensitivity of the insect in question.
“Vasovagal” Response during Ventricular Fibrillation: Incidence and Implications
Authors: WALL T. SCOTT , WASMUND STEPHEN L. , FREEDMAN ROGER A. , AKOUM NAZEM W. , PAGE RICHARD L. , HAMDAN MOHAMED H.
Published: January 2015

Background

The purpose of this study was to assess the relationship between changes in sinus node cycle length (SNCL) during ventricular fibrillation (VF) and the peripheral changes in blood pressure (BP) and sympathetic nerve activity (SNA) in human subjects. We hypothesized that patients with no SNCL shortening during VF have a vasovagal‐like response with a greater decrease in BP and SNA when compared to patients with SNCL shortening.

Methods

SNCL, BP, and SNA recordings were attempted in 24 patients undergoing the implantation of a dual‐chamber implantable defibrillator. Changes were measured during the first 5 seconds of VF and compared with the 5 seconds prior to VF induction.

Results

SNCL shortened during VF in nine patients (mean%∆SNCL = –12 ± 8%) and remained unchanged or lengthened in seven patients (mean%∆SNCL = 7 ± 7%). Eight patients had ventriculoatrial (VA) conduction prohibiting assessment of SNCL changes. In patients with SNCL shortening, the %∆MBP (mean BP) was –47 ± 6% compared to –58 ± 8% in patients with no SNCL shortening (P < 0.01). In patients with VA conduction, the %∆MBP was –54 ± 3%. SNA recordings were successfully obtained in four patients. When compared to baseline, SNA increased by 34 ± 30% in two patients with SNCL shortening, decreased by 25% in one patient with SNCL lengthening, and by 90% in the fourth patient with VA conduction.

Conclusions

We have shown that patients with no SNCL shortening have a significantly greater decrease in MBP during VF when compared to patients with SNCL shortening. The underlying mechanism appears to be reflex mediated with a vasovagal‐like response in patients with no SNCL shortening.
Marker‐assisted backcross breeding to combine multiple rust resistance in wheat
Authors: Mallick Niharika , Vinod  , Sharma J. B. , Tomar R.S. , Sivasamy M. , Prabhu K.V.
Published: January 2015

A widely grown but rust susceptible Indian wheat variety HD2932 was improved for multiple rust resistance by marker‐assisted transfer of genes Lr19, Sr26 and Yr10. Foreground and background selection processes were practised to transfer targeted genes with the recovery of the genome of HD2932. The near‐isogenic lines (NILs) of HD2932 carrying Lr19, Sr26 and Yr10 were individually produced from two backcrosses with recurrent parent HD2932. Marker‐assisted background selection of NILs with 94.38–98.46% of the HD2932 genome facilitated rapid recovery of NILs carrying Lr19, Sr26 and Yr10. In the BC2F2 generation, NILs were intercrossed and two gene combinations of Lr19+Yr10, Sr26 + Yr10 and Lr19+Sr26 were produced. A total of 16 progeny of two gene combinations of homozygous NILs of HD2932 have been produced, which are under seed increase for facilitating the replacement of the susceptible HD2932 with three of the sixteen improved backcross lines with resistance to multiple rusts.
Genetic analysis of threshability in grain sorghum [Sorghum bicolor (L.) Moench]
Authors: Adeyanju Adedayo , Perumal Ramasamy , Tesso Tesfaye
Published: January 2015

The ease with which seeds are detached from panicles is one of the early domestication traits. Genotypes with sticky panicles are hard to thresh, and whenever threshed, the grain tends to remain attached to the glume which reduces market value and processability. This study was conducted to determine the genetic mechanisms underlying the threshability trait in sorghum. Four seed parents and eleven pollinators differing for threshability were intercrossed in Design II mating scheme and the resulting hybrids and the parents were grown in four environments. Threshability was estimated as the ratio of seed yield to panicle weight (TW) and proportion of seeds without sticky glumes (TG). Variation was significant among the entries, inbreds and hybrids with GCA for TG and TW varying markedly. Mean TG for inbred and hybrids of low threshable genotypes was not markedly different indicating that threshability trait is under the control of additive genes with dominant or partially dominant effects. Segregation analysis indicates that the TG trait may be under the control of few major genes with approximately one to three loci affecting the trait.
Investigating the Effects of Applicant Justice Perceptions on Job Offer Acceptance
Authors: Harold Crystal M. , Holtz Brian C. , Griepentrog Brian K. , Brewer Lindsey M. , Marsh Sean M.
Published: January 2015

Drawing on extant recruitment and organizational justice theory, this research examines the effects of justice perceptions on job acceptance decisions across 2 samples (n = 332 and 2,974) of applicants to jobs within the U.S. military. More specifically, we examine justice–job offer acceptance relations relative to other pertinent recruitment predictors including, organizational image, familiarity, person–organization (P–O) fit perceptions, and recruiter behaviors. Findings from both studies support the importance of justice perceptions in influencing job offer acceptance. Fairness perceptions accounted for 29.37% and 19.22% of the unique variance in job offer acceptance, in Studies 1 and 2, respectively. The results of this research provide much needed empirical evidence to the scant literature on actual job acceptance and highlight important practical implications for employers.
Implementation of modern therapy approaches and research for non‐small cell lung cancer in Japan
Authors: Nakanishi Yoichi
Published: January 2015

The genetic backgrounds of the Japanese (or Asians) are, at least in part, different from those of Caucasians. It is necessary to recognize this difference to develop medicine that is both optimized and individualized. In particular, the consideration of ethnic differences is becoming increasingly important for lung cancer medicine. Japanese clinical practice guidelines indicate that some clinical biomarkers, such as epidermal growth factor receptor gene mutations, echinoderm microtubule‐associated protein‐like 4‐anaplastic lymphoma kinase fusion gene and uridine diphosphate glucuronosyltransferase genotypes should be determined in appropriate lung cancer patients. At the present time, tests for these biomarkers are covered by the Japanese national health‐care programme, as is treatment with certain targeted drugs and cytotoxic agents. Therefore, most patients with lung cancer in Japan receive these tests as part of daily practice if their performance status and organ function are judged to be eligible. In addition, ethnic differences in bone marrow toxicity caused by cytotoxic drugs are reflected in treatment choice, and the requirements for the development of treatment modalities suitable for rare targeted populations are also increasing. To meet these requirements, many collaborative groups in Japan that have improved their infrastructure for investigator‐initiated trials and conducted important activities need to provide further optimal treatment modalities for Japanese and Asian patients with lung cancer. Here, the characteristics of lung cancer in Japanese patients, general aspects of medical treatment and the care system in Japan, and representative studies on lung cancer in Japan are reviewed.
The Portfolio Theory of Exchange Rates—Then and Now
Authors: Black Stanley W.
Published: January 2015

In the early 1970s, the portfolio theory of exchange rates with rational expectations was introduced to explain the behavior of floating exchange rates. While attractive in principle, the approach failed along with other theories to provide empirically convincing results. Over the years, the theory has been extended to a general equilibrium setting and modified to include central bank intervention and non‐rational expectations. More recently, it has become a platform for the micro‐structural approach emphasizing order flows, which shows increasing promise as an empirical explanation of exchange rate behavior.
Effects of temperature, storage time and pH on survival of Escherichia coli in source‐separated yellowwater
Authors: Paruch Adam M.
Published: January 2015

Laboratory‐scale experiments on the survival of Escherichia coli in raw, undiluted, freshly collected, source‐separated yellowwater were performed. Concentrations of E. coli and its survival at different temperature regimes and storage times were measured in yellowwater originally cross‐contaminated with faeces and yellowwater purposely contaminated (deliberately spiked) with faecal material. The temperature regimes of cold (4°C), mild (10°C) and warm (22°C) were the limited factors, whereas the storage time of the contaminated yellowwater was unlimited and lasted until the E. coli concentrations reached the limit of detection of < 1 Most Probable Number (MPN)/100 mL. Temperature and pH played the main role in the inactivation and longevity of E. coli in source‐separated yellowwater. The mild storage conditions were the most favourable for the persistence of E. coli, which reached 40 days with a concentration of 2.0 E+03 MPN in 100 mL of undiluted yellowwater.
On G-invexity-type nonlinear programming problems
Authors: Antczak Tadeusz , JimÃ©nez Manuel Arana
Published: January 2015

In this paper, we introduce the concepts of KT-G-invexity and WD$-G-invexity for the considered differentiable optimization problem with inequality constraints. Using KT-G-invexity notion, we prove new necessary and sufficient optimality conditions for a new class of such nonconvex differentiable optimization problems. Further, the so-called G-Wolfe dual problem is defined for the considered extremum problem with inequality constraints. Under WD-G-invexity assumption, the necessary and sufficient conditions for weak duality between the primal optimization problem and its G-Wolfe dual problem are also established.
Experimental Characterization of a Pump–Turbine in Pump Mode at Hump Instability Region
Authors: Yang J. , Pavesi G. , Yuan S. , Cavazzini G. , Ardizzon G.
Published: January 2015

The unsteady phenomena of a low specific speed pump–turbine operating in pump mode were characterized by dynamic pressure measurements and high-speed flow visualization of injected air bubbles. Analyses were carried out on the pressure signals both in frequency and time–frequency domains and by bispectral protocol. The results obtained by high-speed camera were used to reveal the flow pattern in the diffuser and return vanes channels The unsteady structure identified in the return vane channel appeared both at full and part load condition. Furthermore, a rotating stall structure was found and characterized in the diffuser when the pump operated at part load. The characteristics of these two unsteady structures are described in the paper.
Correlation Equations for Natural Convective Heat Transfer From Two Inclined Vertically Spaced Narrow Isothermal Flat Plates
Authors: Kalendar Abdulrahim , Kalendar Ahmed , Karar Sayed , Oosthuizen Patrick H.
Published: January 2015

Natural convective flow over narrow plates induces an inward flow near the edges of the plate causing the flow to be three-dimensional near the edges of the plate. This influences the heat transfer rate near the edges of the plate and is referred to as the edge effect. The primary objective of this paper is to numerically study this edge effect and the interaction of the flows over two inclined vertically separated narrow heated plates of the same size embedded in a plane adiabatic surface. The cases where the plates and surrounding adiabatic surface are inclined at positive or negative angles to the vertical have been considered. Results were obtained by numerically solving the full three-dimensional form of governing equations using the commercial finite volume based software Fluent©. Results have only been obtained for a Prandtl number of 0.7; this being the value existing in the application which involved airflow that originally motivated this study. The results presented here cover Rayleigh numbers between 103 and 107, at all values of W considered, plate width-to-height ratios between 0.2 and 1.2, gap, at all values of W considered, to the plate height ratios of between 0 and 1.5, and, at all values of W considered, angles of inclination of between −45 deg and +45 deg. The effects of the Rayleigh number, dimensionless plate width, dimensionless gap between plates, and inclination angle on the heat transfer rate have been studied in detail. Empirical correlations defining the effect of these parameters on the heat transfer rate have been derived.
Temperature and Entropy Generation Analyses Between and Inside Rotating Cylinders Using Copper–Water Nanofluid
Authors: Torabi Mohsen , Zhang Kaili , Mahmud Shohel
Published: January 2015

Entropy generation is squarely linked with irreversibility, and consequently with exergy destruction within a thermal system. This study concerns with the temperature distribution, and local and volumetric averaged entropy generation rates within a cylindrical system with two solid co-rotating inner and outer parts and the middle nanofluid flow part. Temperature-dependent thermal conductivities for solid materials are included within the modeling. To obtain the temperature formula within all three sections, a combined analytical–numerical solution technique is applied. An exact analytical solution is also obtained, when constant thermal conductivities for solid materials are assumed. The resultant data from the analytical–numerical solution technique is verified against the investigated exact solution. Thereafter, the velocity and temperature fields from the combined analytical–numerical solution technique are incorporated into the entropy generation formulations to obtain the local and volumetric averaged entropy generation rates. Using abovementioned procedure, the effects of thermophysical parameters such as nanoparticles volume concentration, Brinkman number, thermal conductivity parameter ratios, outer temperature boundary condition, internal heat generation rates and velocity ratios on the temperature field, and entropy generation rates are investigated.
Study of Time-Resolved Vortex Structure of In-Cylinder Engine Flow Fields Using Proper Orthogonal Decomposition Technique
Authors: Zhuang Hanyang , Hung David L.S. , Chen Hao
Published: January 2015

The structure of in-cylinder flow field makes significant impacts on the processes of fuel injection, air–fuel interactions, and flame development in internal combustion engines. In this study, the implementation of time-resolved particle image velocimetry (PIV) in an optical engine is presented. Flow field PIV images at different crank angles have been taken using a high-speed double-pulsed laser and a high-speed camera with seeding particles mixed with the intake air. This study is focused on measuring the flow fields on the swirl plane at 30 mm below the injector tip under various intake air swirl ratios. A simple algorithm is developed to identify the vortex structure and to track the location and motion of vortex center at different crank angles. Proper orthogonal decomposition (POD) has been used to extract the ensemble and variation information of the vortex structure. Experimental results reveal that strong cycle-to-cycle variations exist in almost all test conditions. The vortex center is difficult to identify since multiple, but small scale, vortices exist during the early stage of the intake stroke. However, during the compression stroke when only one vortex center exists in most cycles, the motion of vortex center is found to be quite similar at different intake swirl ratios and engine speeds. This is due to the dominant driving force exerted by the piston’s upward motion on the in-cylinder air.
Dynamic Response Optimization of Complex Multibody Systems in a Penalty Formulation Using Adjoint Sensitivity
Authors: Zhu Yitao , Dopico Daniel , Sandu Corina , Sandu Adrian
Published: January 2015

Multibody dynamics simulations are currently widely accepted as valuable means for dynamic performance analysis of mechanical systems. The evolution of theoretical and computational aspects of the multibody dynamics discipline makes it conducive these days for other types of applications, in addition to pure simulations. One very important such application is design optimization for multibody systems. In this paper, we focus on gradient-based optimization in order to find local minima. Gradients are calculated efficiently via adjoint sensitivity analysis techniques. Current approaches have limitations in terms of efficiently performing sensitivity analysis for complex systems with respect to multiple design parameters. To improve the state of the art, the adjoint sensitivity approach of multibody systems in the context of the penalty formulation is developed in this study. The new theory developed is then demonstrated on one academic case study, a five-bar mechanism, and on one real-life system, a 14 degree of freedom (DOF) vehicle model. The five-bar mechanism is used to validate the sensitivity approach derived in this paper. The full vehicle model is used to demonstrate the capability of the new approach developed to perform sensitivity analysis and optimization for large and complex multibody systems with respect to multiple design parameters with high efficiency.
Experimental Study of Low Concentration Sand Transport in Multiphase Air–Water Horizontal Pipelines
Authors: Najmi Kamyar , Hill Alan L. , McLaury Brenton S. , Shirazi Siamack A. , Cremaschi Selen
Published: January 2015

The ultimate goal of this work is to determine the minimum flow rates necessary for effective transport of sand in a pipeline carrying multiphase flow. In order to achieve this goal, an experimental study is performed in a horizontal pipeline using water and air as carrier fluids. In this study, successful transport of sand is defined as the minimum flow rates of water and air at which all sand grains continue to move along in the pipe. The obtained data cover a wide range of liquid and gas flow rates including stratified and intermittent flow regimes. The effect of physical parameters such as sand size, sand shape, and sand concentration is experimentally investigated in 0.05 and 0.1 m internal diameter pipes. The comparisons of the obtained data with previous studies show good agreement. It is concluded that the minimum flow rates required to continuously move the sand increases with increasing sand size in the range examined and particle shape does not significantly affect sand transport. Additionally, the data show the minimum required flow rates increase by increasing sand concentration for the low concentrations considered, and this effect should be taken into account in the modeling of multiphase sand transport.
Internal Resonance Energy Harvesting
Authors: Chen Li-Qun , Jiang Wen-An
Published: January 2015

Internal resonance is explored as a possible mechanism to enhance vibration-based energy harvesting. An electromagnetic device with snap-through nonlinearity is proposed as an archetype of an internal resonance energy harvester. Based on the equations governing the vibration measured from a stable equilibrium position, the method of multiple scales is applied to derive the amplitude–frequency response relationships of the displacement and the power in the first primary resonances with the two-to-one internal resonance. The amplitude–frequency response curves have two peaks bending to the left and the right, respectively. The numerical simulations support the analytical results. Then the averaged power is calculated under the Gaussian white noise, the narrow-band noise, the colored noise defined by a second-order filter, and the exponentially correlated noise. The results demonstrate numerically that the internal resonance design produces more power than other designs under the Gaussian white noise and the exponentially correlated noise. Besides, the internal resonance energy harvester can outperform the linear energy harvesters with the same natural frequencies and in the same size under Gaussian white noise.
Investigation of resist filling profile evolution in microimprint lithography
Authors: Jun Du , Zhengying Wei , Huali Chu , Yubin Zhang
Published: January 2015

In micro-/nanoimprint lithography, the quality of the imprinted patterns can be reflected by their final profile shapes. The evolution of resist filling profiles was investigated through numerical simulations and a visualization experiment. A numerical model based on computational fluid dynamics was built to predict the resist filling process. Meanwhile, a 3D defocusing digital particle image velocimetry system was developed to capture the spatial coordinates of the fluorescent tracer particles at different filling times and reconstruct the filling profiles according to the particles' coordinates. The three-dimensional filling profiles of the resist can help understand this microflow phenomenon and describe the resist filling modes. A comparison of filling profiles for a single mold geometry and a single initial thickness revealed good consistency between the model prediction and experiment. The critical range of conversion from single-peak filling mode to double-peak filling mode was determined, which will provide qualitative information for optimizing mold geometries and process parameters.
Epitaxial niobium dioxide thin films by reactive-biased target ion beam deposition
Authors: Wang Yuhan , Comes Ryan B. , Kittiwatanakul Salinporn , Wolf Stuart A. , Lu Jiwei
Published: January 2015

Epitaxial NbO2 thin films were synthesized on Al2O3 (0001) substrates via reactive bias target ion beam deposition. X-ray diffraction and Raman spectra were used to confirm the tetragonal phase of pure NbO2. Through XPS, it was found that there was a ∼1.3 nm thick Nb2O5 layer on the surface and the bulk of the thin film was NbO2. The epitaxial relationship between the NbO2 film and the substrate was determined. Electrical transport measurement was measured up to 400 K, and the conduction mechanism was discussed.
Mass-spectrum investigation of the phenomena accompanying field electron emission
Authors: Popov Eugeni O. , Kolosko Anatoly G. , Filippov Sergey V. , Fedichkin Igor L. , Romanov Pavel A.
Published: January 2015

This work describes the investigation of carbon nanotube-polymeric nanocomposites and other multiple-tip emitters based on a new reflectron-type time-of-flight mass spectrometer specialized for field emission (FE) tasks, as well as a multichannel acquisition system and on-line processing of the current–voltage characteristics and other parameters of flat multipoint field emitters. Evidence concerning the transfer of large molecular clusters of the emitter material to the opposite electrode for as-prepared samples is presented. It is determined that a vacuum discharge phenomenon in the interelectrode gap is accompanied by strong emission of acetylene. It is also shown that the main volatile product in the FE experiment is hydrogen. The CO and CO2 ratio during the FE experiment is not constant, and hence, arises from different processes. These oxygen-containing volatile products in the spectrum are observed for as-prepared samples at the vacuum discharge, and also arise after long-term heating of the anode surface by an electron current.
Trying Physics: Analyzing the Motion of the Quickest Score in International Rugby
Authors: Goff John Eric , Lipscombe Trevor Davis
Published: January 2015

The hearts of sports fans were stirred recently by the fastest-ever try scored in international rugby. Welsh winger Dafydd Howells crossed the Fijian try line to score a mere six seconds after Angus O'Brien had started the game with a kickoff, in one of the fixtures in rugby's Junior World Cup played on June 2, 2014, in New Zealand. This startlingly quick score, though, is of interest to physics players as well as rugby players. Howells' try serves as an intriguing way to involve students in one of the “core competencies” of physicists—to model events in the real world. And with the Rugby World Cup taking place in 2015 in England, and rugby sevens making its debut in the 2016 Summer Olympics in Brazil (U.S. teams have qualified for both events), rugby is increasing in popularity in America and is even gaining some coverage on television. Thanks to You-Tube, Howells' try is readily available to serve as a laboratory experiment for students to analyze.
Origins of Newton's First Law
Authors: Hecht Eugene
Published: January 2015

Anyone who has taught introductory physics should know that roughly a third of the students initially believe that any object at rest will remain at rest, whereas any moving body not propelled by applied forces will promptly come to rest. Likewise, about half of those uninitiated students believe that any object moving at a constant speed must be continually pushed if it is to maintain its motion.1 That's essentially Aristotle's law of motion and it is so “obviously” borne out by experience that it was accepted by scholars for 2000 years, right through the Copernican Revolution. But, of course, it's fundamentally wrong. This paper tells the story of how the correct understanding, the law of inertia, evolved and how Newton came to make it his first law.
Scaling in Theropod Dinosaurs: Femoral Bone Strength and Locomotion
Authors: Lee Scott
Published: January 2015

In our first article1 on scaling in theropod dinosaurs, the longitudinal stress in the leg bones due to supporting the weight of the animal was studied and found not to control the dimensions of the femur. As a continuation of our study of elasticity in dinosaur bones, we now examine the transverse stress in the femur due to locomotion and find that this effect is important for the geometry of the bone. We find that larger theropods (including Tyrannosaurus rex) were less athletic than smaller theropods.
“Walking” Along a Free Rotating Bicycle Wheel (Round and Round)
Authors: Güémez J. , Fiolhais M.
Published: January 2015

We describe the kinematics, dynamics, and also some energy issues related to Marta mouse's motion when she walks on top of a horizontal bicycle wheel, which is free to rotate like a merry-go-round, as presented recently by Paul Hewitt in the “Figuring Physics” section of this journal. The situation is represented in Fig. 1, which was taken from Ref. 1.
Floating Together on the Top
Authors: Larosi Mohamed Boutinguiza
Published: January 2015

When eating cereal for breakfast, it is common to observe how cereal pieces move to the walls of the bowl. The same thing occurs when having tea— the small leaves tend to move toward the cup walls. While the suspension of objects on liquids due to surface tension is usually discussed in introductory physics courses, this phenomenon is not usually explained in textbooks. Besides, most texts interpret the surface tension as a membrane of liquid that pushes the object up, suspending it completely by the surface tension force. But the surface tension force depends on the liquid-object affinity, and there are also other forces involved in the phenomenon. In this paper the phenomenon is discussed and explained.
The Sound Field Around a Tuning Fork and the Role of a Resonance Box
Authors: Bogacz Bogdan F. , Pędziwiatr Antoni T.
Published: January 2015

Atypical two-tine tuning fork is barely audible when held vibrating at an arm's length. It is enough, however, to touch its base to a table or, better, to a resonance box and the emitted sound becomes much louder. An inquiring student may pose questions: Why is a bare tuning fork such a weak emitter of sound?What is the role of the resonance box?Where does energy connected with larger intensity of emitted acoustic waves come from?
Where are minority physics faculty members?
Authors: White Susan C.
Published: January 2015

There is a significant clustering of African-American physics faculty members at Historically Black Colleges and Universities (HBCUs). Almost half (47%) of African-American physics faculty members are employed by physics departments at HBCUs. Physics departments at 30 HBCUs award degrees in physics; this accounts for about 4% (30 out of 746) of the physics-degree-granting departments in U.S. colleges and universities. Half of all African-American physics faculty members work at just 23 departments, meaning that most physics students will never see a black faculty member.
Using Research-Based Interactive Video Vignettes to Enhance Out-of-Class Learning in Introductory Physics
Authors: Laws Priscilla W. , Willis Maxine C. , Jackson David P. , Koenig Kathleen , Teese Robert
Published: January 2015

Ever since the first generalized computer-assisted instruction system (PLATO1) was introduced over 50 years ago, educators have been adding computer-based materials to their classes. Today many textbooks have complete online versions that include video lectures and other supplements. In the past 25 years the web has fueled an explosion of online homework and course management systems, both as blended learning and online courses. Meanwhile, introductory physics instructors have been implementing new approaches to teaching based on the outcomes of Physics Education Research (PER). A common theme of PER-based instruction has been the use of active-learning strategies designed to help students overcome alternative conceptions that they often bring to the study of physics.2 Unfortunately, while classrooms have become more active, online learning typically relies on passive lecture videos or Kahn-style3 tablet drawings. To bring active learning online, the LivePhoto Physics Group has been developing Interactive Video Vignettes (IVVs) that add interactivity and PER-based elements to short presentations. These vignettes incorporate web-based video activities that contain interactive elements and typically require students to make predictions and analyze real-world phenomena.
Elimination of Influences of the ACTN3 R577X Variant on Oxygen Uptake by Endurance Training in Healthy Individuals
Authors: Silva Michelle S.M. , Bolani Wladimir , Alves Cleber R. , Biagi Diogo G. , Lemos José R. , da Silva Jeferson L. , de Oliveira Patrícia A. , Alves Guilherme B. , de Oliveira Edilamar M. , Negrão Carlos E. , Krieger José E. , Dias Rodrigo G. , Pereira Alexandre C.
Published: January 2015

Aim:

To study the relationship between the ACTN3 R577X polymorphism and oxygen uptake (VO2) before and after exercise training.

Methods:

Police recruits (N = 206, 25 ± 4 y) with RR (n = 75), RX (n = 97), and XX (n = 33) genotypes were selected. After baseline measures, they underwent 18 wk of running endurance training. Peak VO2 was obtained by cardiopulmonary exercise testing.

Results:

Baseline body weight was not different among genotypes. At baseline, XX individuals displayed higher VO2 at anaerobic threshold, respiratory compensation point, and exercise peak than did RR individuals (P < .003). Endurance training significantly increased VO2 at anaerobic threshold, respiratory compensation point, and exercise peak (P < 2 × 10−6), but the differences between XX and RR were no longer observed. Only relative peak VO2 exercise remained higher in XX than in RR genotype (P = .04). In contrast, the increase in relative peak VO2 was greater in RR than in XX individuals (12% vs 6%; P = .02).

Conclusion:

ACTN3 R577X polymorphism is associated with VO2. XX individuals have greater aerobic capacity. Endurance training eliminates differences in peak VO2 between XX and RR individuals. These findings suggest a ceiling-effect phenomenon, and, perhaps, trained individuals may not constitute an adequate population to explain associations between phenotypic variability and gene variations.
Effects of Northbound Long-Haul International Air Travel on Sleep Quantity and Subjective Jet Lag and Wellness in Professional Australian Soccer Players
Authors: Fowler Peter , Duffield Rob , Howle Kieran , Waterson Adam , Vaile Joanna
Published: January 2015

The current study examined the effects of 10-h northbound air travel across 1 time zone on sleep quantity, together with subjective jet lag and wellness ratings, in 16 male professional Australian football (soccer) players. Player wellness was measured throughout the week before (home training week) and the week of (away travel week) travel from Australia to Japan for a preseason tour. Sleep quantity and subjective jet lag were measured 2 d before (Pre 1 and 2), the day of, and for 5 d after travel (Post 1–5). Sleep duration was significantly reduced during the night before travel (Pre 1; 4.9 [4.2−5.6] h) and night of competition (Post 2; 4.2 [3.7−4.7] h) compared with every other night (P < .01, d > 0.90). Moreover, compared with the day before travel, subjective jet lag was significantly greater for the 5 d after travel (P < .05, d > 0.90), and player wellness was significantly lower 1 d postmatch (Post 3) than at all other time points (P < .05, d > 0.90). Results from the current study suggest that sleep disruption, as a result of an early travel departure time (8 PM) and evening match (7:30 PM), and fatigue induced by competition had a greater effect on wellness ratings than long-haul air travel with a minimal time-zone change. Furthermore, subjective jet lag may have been misinterpreted as fatigue from sleep disruption and competition, especially by the less experienced players. Therefore, northbound air travel across 1 time zone from Australia to Asia appears to have negligible effects on player preparedness for subsequent training and competition.
Establishment of the Prediction Equations of 1RM Skeletal Muscle Strength in 60- to 75-Year-Old Chinese Men and Women
Authors: Tan Sijie , Wang Jianxiong , Liu Shanshan
Published: January 2015

The purpose of this study was to establish the one-repetition maximum (1RM) prediction equations of a biceps curl, bench press, and squat from the submaximal skeletal muscle strength of 4–10RM or 11–15RM in older adults. The first group of 109 participants aged 60–75 years was recruited to measure their 1RM, 4–10RM, and 11–15RM of the three exercises. The 1RM prediction equations were developed by multiple regression analyses. A second group of participants with similar physical characteristics to the first group was used to evaluate the equations. The actual measured 1RM of the second group correlated significantly to the predicted 1RM obtained from the equations (r values were from .633–.985), and standard error of estimate ranged from 1.08–5.88. Therefore, the equations can be used to predict 1RM from submaximal skeletal muscle strength accurately for older adults.