bluuebunny/crossref_metadata_2025 huggingface dataset:
A Method for the Analysis of Transient Motion of a Kelvin-Voigt Half-Space
Authors: Yeh Chau-Shioung , Liao Wen-I , Teng Tsung-Jen , Shuy Wen-Shinn
Published: May 2011

In this paper, a modified version of method of steepest descent combining with Durbin's method is proposed to study the transient motion in either an elastic or a viscoelastic half-space. The causal condition is satisfied based on the Durbin's method while the wavenumber integral for any range of frequency is evaluated by applying the modified method of steepest descent. The validity and accuracy of the proposed method is tested by studying the transient response generated by a buried dilatational line source in an elastic half-space, for which the exact solution (Garvin's solution) can be obtained. Then the same formalism is extended to Kelvin-Voigt half-space, and the transient surface motions in elastic or viscoelastic half-spaces media are studied and discussed in details.
Studies on Epitrochoid Gear for Cycloid Drives
Authors: Chang Shinn-Liang
Published: May 2011

Cycloid drives are widely used in the industries because of their excellent characteristics, namely, high gear ratio, smooth transmission, compact size, high efficiency, low noise and long service life. In this paper, a mathematical model of an epitrochoid gear for a cycloid drive with a small tooth number difference has been proposed. Computerized simulation of the generated epitrochoid gear has also been developed. In this paper, the pressure angle, which has an important role in the analysis of cycloid drives as it influences the direction and magnitude of force transmission in gears, is derived based on the theory of differential geometry. The rack cutter profile, which is the fundamental tooth profile of a hob cutter, which in turn is the main manufacturing process of epitrochoid gear, has been obtained based on the theory of gearing. It is anticipated that the results from this paper will be beneficial to the design, analysis and manufacture of cycloid drives.
Oscillatory Flows over a Permeable Wavy Boundary
Authors: Hsiao Shih-Chun , Liu Philip L.-F.
Published: May 2011

In this paper viscous boundary layer flows above and inside a permeable wavy bed are studied. The flow motions are driven by an oscillatory horizontal velocity just outside the Stokes boundary layer above the bed. Analytical and numerical solutions are obtained for both the oscillatory velocity component and the steady streaming inside the permeable bed, the Stokes boundary layer and the outer boundary layer. Two specific situations are examined: (1)Weak oscillatory motions over a wavy bed with finite slope and (2) strong oscillatory motions over a small wavy slope. In both situations, the slip (tangential) velocity and the normal velocity do not vanish on the wavy surface because of the permeability. The magnitude of the bed shear stress decreases as the permeability increases. The permeability can also affect significantly the steady streaming patterns; they could change from having two pairs of recirculating cells above an impervious wavy bed to one pair of recirculating cells above a wavy permeable bed.
A Family of Explicit Dissipative Algorithms for Pseudodynamic Testing
Authors: Chang S.- Y.
Published: May 2011

The α-function method is a family of second-order explicit methods with controlled numerical dissipation. Thus, it is very promising for the pseudodynamic testing of a system where high frequency responses are of no interest. This is because that favorable numerical dissipation can suppress the spurious growth of high frequency responses, which might arise from numerical and/or experimental errors during a test. Furthermore, the implementation of an explicit method for the pseudodynamic testing is much simpler than for an implicit method. The superiority of using this method in performing a pseudodynamic test was verified both analytically and experimentally. In fact, results of error propagation analysis reveal that the spurious growth of high frequency responses can be suppressed and less error propagation is identified when compared to the Newmark explicit method. Actual tests were conducted pseudodynamically to confirm all the analytical results. It is also illustrated that although the high frequency response is insignificant to the total response it may be significantly amplified and propagated and finally destroys the pseudodynamic test results.
Cylindrical Stress Waves in Poroelastic Flat Slabs
Authors: Reddy P. M. , Tajuddin M.
Published: May 2011

Biot's poroelastic theory is employed to study stress wave propagation in an infinite slab of arbitrary thickness. The frequency equation is obtained each for pervious and impervious surfaces for a nondissipative medium. Appropriate numerical data is presented in the form of graphs and then results are discussed. Waves in a thin bar and in a semi-infinite slab are discussed as limiting cases.
Enstrophy Cascade and Smagorinsky Model of 2D Turbulent Flows
Authors: Huang Mei-Jiau
Published: May 2011

Direct numerical simulations of 2D turbulent flows, freely decaying as well as forced, are performed to examine the mechanism of the enstrophy cascade and serve as a template of developing LES models. The stretching effect on the 2D vorticity gradients is emphasized on the analogy of the stretching effect on 3D vorticity. The enstrophy cascade rate, the Reynolds stresses and the associated eddy viscosity for 2D turbulence are correspondingly derived and investigated. Proposed herein is that the enstrophy cascade rate to be modeled in a large-eddy simulation can be and should be calculated using the only available large-eddy information, especially when the Reynolds number is not very large or when the flow is not stationary.

The simulation results suggest all Kolmogorov's, Kraichnan's, and Saffman's similarity spectra. The Kolmogorov's spectrum appears in front of forced wave numbers and creates a subrange of a zero enstrophy cascade rate and a constant energy cascade rate. The Saffman's spectrum is the dissipation spectrum at large wave numbers. Kraichnan's spectrum shows up at intermediate wave numbers when the Reynolds number is sufficiently high. When the Smagorinsky model is employed for a large eddy simulation, its inability of capturing the significant reverse cascade phenomenon as observed in the DNS data becomes a fatal defect. Nonetheless, if only the mean cascade rate is concerned, the required Smagorinsky constant is evaluated using the DNS data and compared with the theoretical prediction of the Kraichnan's spectrum.
The Health Monitoring of Bridges using Artificial Neural Networks
Authors: Liu Pei-Ling , Sun Shyh-Jang
Published: May 2011

This study develops a neural network system to monitor the safety of a bridge structure. A truck of constant mass is driven at constant speed through the target bridge. Then, the maximal and minimal values of the bridge elongations are processed by a monitoring system to evaluate the current condition of the bridge. The monitoring system is composed of parallel backpropagation neural networks. Each neural network monitors a part of the bridge. The neural networks are trained using simulation data. The numerical example shows that the monitoring system is effective in the damage detection of the bridge.
Analysis of Wave Propagation in Infinite Piezoelectric Plates
Authors: Wu C. Y. , Chang J. S. , Wu K. C.
Published: May 2011

An analysis is presented for wave propagation in infinite homogeneous elastic plates of piezoelectric materials. The analysis is an extension to the work by Shuvalov [1] on wave propagation in general anisotropic elastic plates. A real form of dispersion equation is provided for a piezoelectric plate subjected to different boundary conditions on the plate surfaces. Perturbation theory [2] is exploited to obtain long-wavelength low-frequency approximation for physical quantities of wave propagation, including wave amplitude, stress, electric potential, electric displacement and velocity.
Dispersion mechanisms and the effect of parameter uncertainty on hydrologic response in urban catchments
Authors: Cantone Joshua , Schmidt Arthur
Published: May 2011

The link between river network structure and hydrologic response for natural watersheds has been the subject of ongoing research for the past 30 years. In this paper we investigate the link between sewer network structure and hydrologic response in urban catchments. It has been shown in natural watersheds that there are dispersion mechanisms that contribute to the impulse response function of the catchment: hydrodynamic dispersion, geomorphologic dispersion, and hydrodynamic dispersion. We introduce a fourth dispersion mechanism, intrastate dispersion, which accounts for the variance in conduit (e.g., slope, length, diameter, etc.) and overland region input parameters (e.g., slope, area, imperviousness, etc.) within an order. This dispersion mechanism is found to be the second largest contributor to the total dispersion in the urban catchments analyzed, contributing less than hydrodynamic dispersion but more than kinematic and geomorphologic dispersion. This is primarily a result of the shorter network travel times observed in urban catchment. The dispersion mechanisms are incorporated in the Illinois Urban Hydrologic Model, which is a recently developed probabilistic approach for predicting the hydrologic response in highly urbanized catchments. Furthermore, an analysis is performed to help better understand the uncertainty in the predicted hydrologic response that is introduced by spatial variation in conduit and overland input parameters. It is identified that conduit slope and length are the greatest sources of uncertainty in the predicted direct runoff hydrograph for the CDS‐51 catchment in the village of Dolton, Illinois, and the CDS‐36 catchment in the city of Chicago, Illinois.
Gastric Bypass Surgery Reduces Plasma Ceramide Subspecies and Improves Insulin Sensitivity in Severely Obese Patients
Authors: Huang Hazel , Kasumov Takhar , Gatmaitan Patrick , Heneghan Helen M. , Kashyap Sangeeta R. , Schauer Philip R. , Brethauer Stacy A. , Kirwan John P.
Published: May 2011

Bariatric surgery is associated with near immediate remission of type 2 diabetes and hyperlipidemia. The mechanisms underlying restoration of normal glucose tolerance postoperatively are poorly understood. Herein, we examined the effect of Roux‐en‐Y gastric bypass surgery (RYGB) on weight loss, insulin sensitivity, plasma ceramides, proinflammatory markers, and cardiovascular risk factors before and at 3 and 6 months after surgery. Thirteen patients (10 female; age 48.5 ± 2.7 years; BMI, 47.4 ± 1.5 kg/m2) were included in the study, all of whom had undergone laparoscopic RYGB surgery. Insulin sensitivity, inflammatory mediators and fasting lipid profiles were measured at baseline, 3 and 6 months postoperatively, using enzymatic analysis. Plasma ceramide subspecies (C14:0, C16:0, C18:0, C18:1, C20:0, C24:0, and C24:1) were quantified using electrospray ionization tandem mass spectrometry after separation with HPLC. At 3 months postsurgery, body weight was reduced by 25%, fasting total cholesterol, triglycerides, low‐density lipoproteins, and free fatty acids were decreased, and insulin sensitivity was increased compared to presurgery values. These changes were all sustained at 6 months. In addition, total plasma ceramide levels decreased significantly postoperatively (9.3 ± 0.5 nmol/ml at baseline vs. 7.6 ± 0.4 at 3 months, and 7.3 ± 0.3 at 6 months, P < 0.05). At 6 months, the improvement in insulin sensitivity correlated with the change in total ceramide levels (r = −0.68, P = 0.02), and with plasma tumor necrosis factor‐α (TNF‐α) (r = −0.62, P = 0.04). We conclude that there is a potential role for ceramide lipids as mediators of the proinflammatory state and improved insulin sensitivity after gastric bypass surgery.
Oblique radiative shocks, including their interactions with nonradiative polytropic shocks
Authors: Doss F. W. , Drake R. P. , Myra E. S.
Published: May 2011

A theory of shocks dominated by radiation energy flux in optically mixed thin-upstream thick-downstream systems, in which the temperature immediately ahead and some short distance behind the shock front are equilibrated by radiation transport, is presented. This theory is applied to determine properties of the normal and oblique radiative shock, followed by applications to interactions when radiative and polytropic shocks are present in the same system. Comparison with experimental data is presented.
Off-axis fishbone-like instability and excitation of resistive wall modes in JT-60U and DIII-D
Authors: Okabayashi M. , Matsunaga G. , deGrassie J. S. , Heidbrink W. W. , In Y. , Liu Y. Q. , Reimerdes H. , Solomon W. M. , Strait E. J. , Takechi M. , Asakura N. , Budny R. V. , Jackson G. L. , Hanson J. M. , La Haye R. J. , Lanctot M. J. , Manickam J. , Shinohara K. , Zhu Y. B.
Published: May 2011

An energetic-particle (EP)-driven “off-axis-fishbone-like mode (OFM)” often triggers a resistive wall mode (RWM) in JT-60U and DIII-D devices, preventing long-duration high-βN discharges. In these experiments, the EPs are energetic ions (70–85 keV) injected by neutral beams to produce high-pressure plasmas. EP-driven bursting events reduce the EP density and the plasma rotation simultaneously. These changes are significant in high-βN low-rotation plasmas, where the RWM stability is predicted to be strongly influenced by the EP precession drift resonance and by the plasma rotation near the q=2 surface (kinetic effects). Analysis of these effects on stability with a self-consistent perturbation to the mode structure using the MARS-K code showed that the impact of EP losses and rotation drop is sufficient to destabilize the RWM in low-rotation plasmas, when the plasma rotation normalized by Alfvén frequency is only a few tenths of a percent near the q=2 surface. The OFM characteristics are very similar in JT-60U and DIII-D, including nonlinear mode evolution. The modes grow initially like a classical fishbone, and then the mode structure becomes strongly distorted. The dynamic response of the OFM to an applied n=1 external field indicates that the mode retains its external kink character. These comparative studies suggest that an energetic particle-driven “off-axis-fishbone-like mode” is a new EP-driven branch of the external kink mode in wall-stabilized plasmas, analogous to the relationship of the classical fishbone branch to the internal kink mode.
Uniaxial magnetic anisotropy for thin Co films on glass studied by magnetooptic Kerr effect
Authors: Kuschel T. , Becker T. , Bruns D. , Suendorf M. , Bertram F. , Fumagalli P. , Wollschläger J.
Published: May 2011

Thin Co films of different thickness deposited on glass are investigated by magnetooptic Kerr effect to study the uniaxial magnetic anisotropy of these films. The direction of the uniaxial magnetic anisotropy is determined from the azimuthal dependence of the magnetic remanence and differs with increasing thickness of the Co film investigated by x-ray reflectivity. Our experiments reveal that preparation conditions like temperature, deposition rate, or obliqueness of deposition cannot be the reason for this rotation effect of the uniaxial magnetic anisotropy. Also, strain in the substrate and possible textures in the film structure can be excluded as the origin of the magnetic behavior as studied by grazing incidence wide angle x-ray scattering. Thus, probably only the substrate shape in connection with the amorphous or polycrystalline film structure can explain the rotation of the uniaxial magnetic anisotropy.
Response to “Comment on ‘Acoustic solitons in inhomogenous pair-ion plasmas’” [Phys. Plasmas 18, 054701 (2011)]
Authors: Shah Asif , Mahmood S. , Haque Q.
Published: May 2011

The quantity np0(0) is different from np0(x) and same is true for vp0(0), vp0(x). Taking these differences into account and considering the mathematical relation vp0(x)= 1/np0(x), it can easily be shown that derivatives of these space dependent densities and velocities are linked through the relation ∂vp0(x)/∂η=-1/np02(x)∂np0(x)/∂η. We show that constraint (1) of the comment can also be transformed to derivative transformation relation. This derivative transformation relation can be used in the derivation of the KdV like equation and our model is valid for inhomogenous pair ion plasma. We mathematically and physically prove that the objections in the comment are false and baseless.
Current-induced magnetic and thermal effects in materials with combined magnetic and resistive transitions
Authors: Dzhezherya Yu. I. , Tovstolytkin A. I. , Klymuk E. S.
Published: May 2011

Current-induced effects in materials for which the first-order magnetic phase transition is accompanied by a strong change in electric resistivity are theoretically analyzed. An approach is developed that describes the magnetization and conductivity of thin film systems based on such material, for the temperature interval where two magnetic phases coexist. The changes in magnetic state and system temperature, originating from the Joule heating, are analyzed for the steady-state condition of the heat exchange with the surrounding medium. A way to achieve the temperature stabilization effect in the system is suggested. The possibility of tuning the system temperature by changing the external magnetic field is demonstrated.
Theory of magnetoelectric effect in laminate composites considering two-dimensional internal stresses and equivalent circuit
Authors: Bao Binghao , Luo Ying
Published: May 2011

By taking into account the transverse stresses produced in both the transversely poled piezoelectric plate and the longitudinally magnetized magnetostrictive plate, we develop an 2D stresses magnetoelectric (ME) effect theoretical model. The ME voltage expressions are given by combing constitutive equations and equation of motion for the ME element, accompanied by boundary conditions and charge source equivalent circuit. Theoretical results show the detailed relationships among ME voltage coefficient, geometric parameters, and physical parameters of the composites, as well as the circuit parameters. Compared with 1D stresses theory, the 2D stresses theoretical results are in better agreement with the experimental data.
Calculation of the vertical and horizontal electron mobilities in InAs/GaSb superlattices
Authors: Szmulowicz F. , Brown G. J.
Published: May 2011

Efficient perpendicular transport of carriers by drift and diffusion in InAs/GaSb superlattice-based devices is necessary for achieving high device figures of merit. However, the values of perpendicular mobilities are usually inferred indirectly or through nonstandard experiments. Treating perpendicular and transverse mobilities on equal footing, we present here the results of a calculation of low-temperature perpendicular and transverse electron mobilities in InAs/GaSb superlattices as limited by interface-roughness scattering. Using the calculated mobility curves, it is possible to infer the value of the vertical mobility from measurements of the horizontal mobility.
Improved diamond surfaces following lift-off and plasma treatments as observed by x-ray absorption spectroscopy
Authors: Stacey Alastair , Drumm Virginia S. , Fairchild Barbara A. , Ganesan Kumar , Rubanov Sergey , Kalish Rafi , Cowie Bruce C. C. , Prawer Steven , Hoffman Alon
Published: May 2011

We have investigated the nature of the residual damage in diamond crystals following the ion implantation/graphitization “lift-off” process, using near-edge x-ray absorption fine structure spectroscopy and transmission electron microscopy. A defective but crystalline interface is found, which displays dense pre-edge unoccupied states and an almost complete loss of the core-level C 1s exciton signature. This residual crystalline damage is resistant to standard chemical etching, however a hydrogen plasma treatment is found to completely recover a pristine diamond surface. Analysis and removal of residual ion-induced damage is considered crucial to the performance of many diamond device architectures.
Li2CO3 as an n-type dopant on Alq3-based organic light emitting devices
Authors: Kao Po-Ching , Lin Jie-Han , Wang Jing-Yuan , Yang Cheng-Hsien , Chen Sy-Hann
Published: May 2011

Lithium carbonate (Li2CO3) is used as an n-type dopant to improve the electro-optical properties of the Alq3-based organic light-emitting diodes (OLEDs). Li2CO3-doped tris(8-hydroxyquinolinato) aluminum (Alq3) layers with various concentrations were prepared by the co-evaporating method. When 10% Li2CO3 was doped into an Alq3 electron-transporting layer, device properties such as the turn-on voltage, the maximum luminance, and the device efficiency were improved, becoming better than LiF and comparable to devices with Cs2CO3 dopants. Li2CO3-doped Alq3 layers possess an enhanced electron injection, transporting and hole-blocking ability. The higher mobility of the Li2CO3-doped samples has been derived using space-charge-limited current (SCLC) measurements. X-ray and ultraviolet photoelectron spectroscopy results show that some electrons transfer from Li2CO3 into Alq3, which increases the electron concentration in Alq3 films and moves the Fermi level close to the lowest unoccupied molecular orbital (LUMO) of Alq3. The charge transfer was further confirmed by absorption and photoluminescence (PL) spectra. Therefore, the electron injection and transport efficiency are both enhanced due to a lower electron injection barrier and a higher electron mobility, which improve the charge carrier balance in OLEDs and lead to better device efficiency.
Deconvolution of damping forces with a nonlinear microresonator
Authors: Elliott Bevan , Behlow Herbert W. , Dickel Doyl , Skove Malcolm J. , Rao Apparao M. , Keskar Gayatri
Published: May 2011

We report a fully electrical microcantilever device that utilizes capacitance for both actuation and detection and show that it can characterize various gases with a bare silicon microcantilever. We find the motion of the cantilever as it rings down when the oscillating force is removed, by measuring the voltage induced by the oscillating capacitance in the microcantilever/counterelectrode system. The ringdown waveform was analyzed using an iterative numerical algorithm to calculate the oscillator motion, modeling the cantilever/electrode capacitance to calculate the electrostatic force. We find that nonlinearity in the motion of the cantilever is not necessarily a disadvantage. After calibration, we simultaneously measure viscosity and density of several gaseous mixtures, yielding viscosities within ±2% and densities within ±6% of NIST values.
Giant magnetic flux jumps in single crystals of Ba0.6K0.4Fe2As2
Authors: Choi Ki-Young , Jeon Gun Sang , Wang X. F. , Chen X. H. , Wang Xiao-Lin , Jung Myung-Hwa , Lee Sung-Ik , Park Gangseo
Published: May 2011

Giant magnetic flux jumps are observed in magnetic hysteresis loops of Ba0.6K0.4Fe2As2 single crystals. The size of the flux jumps, which appear only at low temperatures (T<4 K), is so large that it can transform the whole superconducting state into the normal state. The recovery rate to the superconducting state is rather slow, although the superconducting state is almost fully recovered. We show that theoretical predictions based on the adiabatic approach with nonlocal electrodynamics give a good explanation of the flux jumps observed in the single crystals of Ba0.6K0.4Fe2As2.
A simple method to prepare self-assembled organic-organic heterobilayers on metal substrates
Authors: Sun L. D. , Liu C. Y. , Queteschiner D. , Zeppenfeld P.
Published: May 2011

We demonstrate a self-assembly based simple method to prepare organic-organic heterobilayers on a metal substrate. By either sequential- or co-deposition of para-sexiphenyl (p-6P) and pentacene molecules onto the Cu(110) surface in ultrahigh vacuum, p-6P/pentacene/Cu(110) heterobilayer is synthesized at room temperature. The layer sequence of the heterostructure is independent of the growth scenario indicating the p-6P/pentacene/Cu(110) is a self-assembled structure with lowest energy. Besides, the bilayer shows a very high orientational ordering and is thermally stable up to 430K.
Effect of farm size on performance and profitability of hair goat production in Isparta, Turkey
Authors: Demircan V. , Yilmaz H. , Gul M. , Koknaroglu H.
Published: May 2011

In this study, different goat farms in Isparta province, which have considerable importance in goat farming in Turkey, were compared in terms of performance, production cost and profitability and the most profitable farm size was determined. Data were obtained by conducting a questionnaire with 92 goat farms selected by stratified random sampling method. Goat farms were divided into three groups according to their size and were then analysed. Accordingly farms were assigned as Group I (1–100 goats, 34 farms), Group II (101–300 goats, 26 farms) and Group III (>300 goats, 17 farms). It was found that small farms had higher lactation milk yield (kg/goat) and concentrate consumption (P < 0.05). It was also found that farms with higher capacity were advantageous in terms of economic criteria (P < 0.05). Results showed that as farm size increased, production cost per animal unit decreased (P < 0.05) and net profit per animal unit tended to increase (P > 0.05).
Effect of dietary supplementation with fish oil during the transition period on milk production, plasma metabolites and postpartum anoestrus interval in grazing dairy cows
Authors: Mendoza A. , Crespi D. , Hernández A. , Roura N. , Valentín H. , La Manna A. , Cavestany D.
Published: May 2011

Inclusion of fish oil (FO) in the diet of dairy cows could improve the energy status and milk yield and reduce the interval from calving to first postpartum ovulation, but the effects may differ depending on the specific period of supplementation. To test these hypotheses, 28 pregnant Holstein heifers were randomly assigned to four treatments in a 2 × 2 factorial design: prepartum oral drench of FO (0 or 140 g/cow.day) for 21 days before calving, and/or postpartum oral drench of FO (0 or 190 g/cow.day) for 21 days after calving. Prepartum, heifers grazed in native pastures with supplements of wheat silage and wheat bran, while postpartum, cows grazed on improved pastures with addition of concentrates and corn silage. No interaction between prepartum and postpartum FO was detected for any variable analysed. Prepartum and postpartum total DM intake, milk yield, protein yield and percentage were not different among treatments. Milk fat percentage (3.83 versus 3.34 ± 0.10%) and yield (0.88 versus 0.73 ± 0.04 kg/day) decreased with postpartum FO but were not affected by prepartum FO. Prepartum and postpartum body condition score and plasma concentration of non-esterified fatty acids and cholesterol were not different among treatments, but urea concentration was higher in cows drenched with FO during prepartum (5.91 versus 4.64 ± 0.35 mM). Proportion of cows that ovulated the dominant follicle of the first postpartum wave and days to first postpartum ovulation, as determined by ovarian ultrasonography, were not affected by drenching with FO, but size of the dominant follicle in the first wave was decreased when FO was drenched only during the pre- or postpartum period compared with drenching in both periods. Dietary supplementation with FO during the postpartum period affected milk fat synthesis but more research is needed to establish its effects on resumption of ovarian activity in grazing dairy cows.
Influence of housing type and age in female pigs. 1. Effects on growth performance and fat deposition and distribution in the carcasses of female Large White × Landrace pigs grown from 5.5 to 120 kg liveweight
Authors: Trezona M. , Mullan B. P. , D'Souza D. N. , Dunshea F. R. , Pethick D. W. , D'Antuono M. , Speijers J. , Pluske J. R.
Published: May 2011

One hundred and sixty female Large White × Landrace pigs were obtained at 3 weeks of age, average liveweight (LW) 5.5 ± 0.08 kg, stratified on LW and allocated to four treatments in a factorial design that consisted of two housing treatments, conventional (C) or deep-litter (D), across two growth periods: early (3–13 weeks of age) and late (13–24 weeks of age). At 13 weeks of age eight pigs per treatment (n = 32) were slaughtered, and the remaining pigs (n = 128) moved to new pens where they remained until slaughter at 24 weeks of age. Moving pigs into a new housing system caused a growth reduction, as indicated by significantly lower LW (P = 0.003), compared with pigs that remained within the same housing system, regardless of whether the new system was C or D. Carcass composition results indicated that pigs finished in the D system (24 weeks of age) were not fatter than pigs raised in C housing, with pigs raised entirely in C housing tending to be the fattest (P = 0.090). There was an effect of housing on fat distribution within the carcass where pigs finished in D housing had significantly less fat in the belly primal compared with pigs finished in the C facilities (35.3 versus 31.2%, P = 0.030). These findings suggest that the strategy of moving pigs from D housing to C housing for finishing, to reduce carcass fatness and improve pig growth performance, was not successful as pigs were fatter, lighter and less efficient than pigs of the same age housed in D from wean to finish.
Influence of housing type and age in female pigs. 2. Effects on biochemical indicators of fat metabolism and the fatty acid profile of belly fat and back fat depots
Authors: Trezona M. , Mullan B. P. , D'Souza D. N. , Dunshea F. R. , Pethick D. W. , D'Antuono M. , McGrath M. , Pluske J. R.
Published: May 2011

Weaning pigs into deep-litter (D) housing systems and then moving them into conventional (C) housing facilities affects the growth paths of the pigs and can result in differences in carcass composition which may be explained by altered fat metabolism. To examine this proposition experimentally, 160 female Large White × Landrace pigs were obtained at 3 weeks of age, average liveweight 5.5 ± 0.08 kg and were stratified by weight to four treatments. The treatments consisted of two housing treatments, C or D, across two growth periods: (i) early (3–13 weeks of age); and (ii) late (13–24 weeks of age). At ~13 weeks of age eight pigs per experimental treatment (n = 32) were slaughtered and the remaining pigs (n = 128) moved to new pens where they were housed until slaughter at ~24 weeks of age. To 13 weeks of age, the effect of housing type on lipogenesis did not reach significance (P > 0.05). At 24 weeks of age there were some treatment differences in fatty acid profile (P ≤ 0.05) and the concentration of plasma glycerol (P = 0.002) and non-esterified fatty acids (P = 0.019). There were trends for lipogenic enzyme activity to differ between treatments also (P < 0.100). Results suggested fat deposition was lower in D-finished pigs compared with C-finished pigs, rejecting the hypothesis that D-finished pigs would be fatter. However, most of the differences in the biochemical measurements were explained by the significant reduction in growth that occurred when pigs changed housing environments, rather than as an effect of the housing environment itself. Indicators of lipogenesis suggested that lipogenic rate was lowest in pigs moved from C to D housing compared with other treatment groups that had remained within the same housing, C or D, throughout the experiment or had moved from D housing to C housing at 13 weeks of age.
A complementary forage system whole-farm study: forage utilisation and milk production
Authors: Fariña S. R. , Garcia S. C. , Fulkerson W. J.
Published: May 2011

Australian dairy farmers are facing decreasing availability of land and water and declining terms of trade. In this context, systems that are able to increase milk production per ha from home-grown feed, beyond the potential of pasture only, are sought. The complementary forage system (CFS), combining an area with a rotational sequence of two or three forage crops per year with an area of pasture in 35 and 65% of the farm area, respectively, was developed for this purpose. A 2-year whole-farm study with 100 milking cows on 21.5 ha evaluated the feasibility of achieving 25 t DM/ha.year of home-grown feed and converting this into 35 000 L of milk/ha.year by the implementation of such CFS. Utilisation and nutritive value of all forages and milk yields of individual cows were measured daily, body condition and bodyweight weekly, and milk composition fortnightly. Over 26 t DM/ha.year was utilised over the whole CFS farm for the 2 years of the study. This utilised forage had a mean metabolisable energy value of 10.2 MJ/kg DM and crude protein content of 20.5% DM. From this, a total yield of 27 835 L of milk/ha.year from home-grown feed was obtained, which is higher than any other whole-farm study reported in the literature. Daily pasture intake was the variable with the highest impact on milk yield, and significant differences were found in body condition and milk yield of cows calving in either autumn or spring. This study warrants further investigation to determine the environmental and economic sustainability of the implementation of the CFS.
Gendered production and consumption in rural Africa
Authors: Kevane Michael
Published: May 2011

Recent research underscores the continued importance of gender in rural Africa. Analysis of interactions within households is becoming more sophisticated and continues to reject the unitary model. There is some evidence of discriminatory treatment of girls relative to boys, although the magnitudes of differential investments in health and schooling are not large and choices seem quite responsive to changes in opportunity costs. Social norms proscribing and prescribing male and female economic behavior remain substantial, extending into many domains, especially land tenure. Gender constructions are constantly evolving, although there is little evidence of rapid, transformative change in rural areas.
The role of rehearsals in self‐generated prospective memory tasks
Authors: Szarras Kaja , Niedźwieńska Agnieszka
Published: May 2011

In order to inquire into the nature of retrieval in prospective memory in a naturalistic context, we investigated the number and circumstances of rehearsals of different kinds of intentions to be pursued during a single time period. Thirty‐six students were given four minutes to generate a list of tasks they were planning to perform over the course of 10 days. During this retention interval, they were provided with pocket‐size diaries in which they recorded the details of each occasion they thought about the tasks previously listed. As to the nature of any triggers or cues that prompted rehearsal, the participants were asked to choose one of three alternatives: (1) association with an internal or an external cue that accidently appeared in the surroundings (accidental rehearsals), (2) deliberate thinking, e.g. while planning (self‐initiated rehearsals), (3) recollection that spontaneously popped into one's mind for no apparent reason (no‐trigger rehearsals). The results showed that thoughts about intended actions appeared more often after accidental cues than for no apparent reason. However, the relative contribution of self‐initiated triggers to the rehearsal process was substantial: Most importantly, it was the self‐initiated rehearsal that differentiated between executed and unexecuted actions. In addition, the most activated intention resulted in a higher frequency of no‐trigger and self‐initiated rehearsals than the remaining intentions. Finally, perceived intention importance was positively related to both the number of rehearsals and the likelihood of successful task completion. The results are discussed with regard to which factors may be crucial for the successful performance of participants’ own self‐generated intentions in a natural setting. The role of deliberate rehearsal in specifying the details of the intended action and its designated retrieval context is highlighted.
A theoretical model for the electrical properties of chromium thin films sputter deposited at oblique incidence
Authors: Besnard Aurélien , Martin Nicolas , Carpentier Luc , Gallas Bruno
Published: May 2011

Chromium thin films are prepared by magnetron sputtering using the glancing angle deposition (GLAD) method. The electrical conductivity of the films exhibiting an inclined columnar structure is investigated. An analytical three-dimensional model is proposed in order to predict the evolution of the electrical conductivity as a function of the columns' orientation. This model is based on two types of electron scattering mechanisms, which are simultaneously operational: the isotropic background scattering at the grain boundary and the scattering due to electron dispersion at the column boundary. The developed analytical expressions enable systematic studies of different processes and film parameters, especially the column angle β as well as the sputtering pressure used during the GLAD deposition. The theoretical and experimental results are compared. It is found that the column angle β must reach a threshold value to significantly reduce the electrical conductivity of chromium thin films close to one order of magnitude. The effect of the sputtering pressure on the structure of films and their electrical behaviours are also studied and well predicted by the proposed model. Finally, a comprehensive discussion of the applicability of the model is presented.
Differences of weighted composition operators acting from Bloch space to 𝐻^{∞}
Authors: Hosokawa Takuya , Ohno Shûichi
Published: May 2011

We study the boundedness and compactness of the differences of two weighted composition operators acting from the Bloch space

B

\mathcal B

to the space

H
∞

H^\infty

of bounded analytic functions on the open unit disk. Such a study has a relationship to the topological structure problem of composition operators on

H
∞

H^\infty

. Using this relation, we will estimate the operator norms and the essential norms of the differences of two composition operators acting from

B

\mathcal B

to

H
∞

H^\infty

.
Improved similarity scores for comparing motifs
Authors: Tanaka Emi , Bailey Timothy , Grant Charles E. , Noble William Stafford , Keich Uri
Published: May 2011

Motivation: A question that often comes up after applying a motif finder to a set of co-regulated DNA sequences is whether the reported putative motif is similar to any known motif. While several tools have been designed for this task, Habib et al. pointed out that the scores that are commonly used for measuring similarity between motifs do not distinguish between a good alignment of two informative columns (say, all-A) and one of two uninformative columns. This observation explains why tools such as Tomtom occasionally return an alignment of uninformative columns which is clearly spurious. To address this problem, Habib et al. suggested a new score [Bayesian Likelihood 2-Component (BLiC)] which uses a Bayesian information criterion to penalize matches that are also similar to the background distribution.

Results: We show that the BLiC score exhibits other, highly undesirable properties, and we offer instead a general approach to adjust any motif similarity score so as to reduce the number of reported spurious alignments of uninformative columns. We implement our method in Tomtom and show that, without significantly compromising Tomtom's retrieval accuracy or its runtime, we can drastically reduce the number of uninformative alignments.

Availability and Implementation: The modified Tomtom is available as part of the MEME Suite at http://meme.nbcr.net.

Contact:  uri@maths.usyd.edu.au; e.tanaka@maths.usyd.edu.au

Supplementary Information:  Supplementary data are available at Bioinformatics online.
Rain increases the energy cost of bat flight
Authors: Voigt Christian C. , Schneeberger Karin , Voigt-Heucke Silke L. , Lewanzik Daniel
Published: May 2011

Similar to insects, birds and pterosaurs, bats have evolved powered flight. But in contrast to other flying taxa, only bats are furry. Here, we asked whether flight is impaired when bat pelage and wing membranes get wet. We studied the metabolism of short flights inCarollia sowelli, a bat that is exposed to heavy and frequent rainfall in neotropical rainforests. We expected bats to encounter higher thermoregulatory costs, or to suffer from lowered aerodynamic properties when pelage and wing membranes catch moisture. Therefore, we predicted that wet bats face higher flight costs than dry ones. We quantified the flight metabolism in three treatments: dry bats, wet bats and no rain, wet bats and rain. Dry bats showed metabolic rates predicted by allometry. However, flight metabolism increased twofold when bats were wet, or when they were additionally exposed to rain. We conclude that bats may not avoid rain only because of sensory constraints imposed by raindrops on echolocation, but also because of energetic constraints.
Craniofacial form and function in Metriorhynchidae (Crocodylomorpha: Thalattosuchia): modelling phenotypic evolution with maximum-likelihood methods
Authors: Young Mark T. , Bell Mark A. , Brusatte Stephen L.
Published: May 2011

Metriorhynchid crocodylomorphs were the only group of archosaurs to fully adapt to a pelagic lifestyle. During the Jurassic and Early Cretaceous, this group diversified into a variety of ecological and morphological types, from large super-predators with a broad short snout and serrated teeth to specialized piscivores/teuthophages with an elongate tubular snout and uncarinated teeth. Here, we use an integrated repertoire of geometric morphometric (form), biomechanical finite-element analysis (FEA; function) and phylogenetic data to examine the nature of craniofacial evolution in this clade. FEA stress values significantly correlate with morphometric values representing skull length and breadth, indicating that form and function are associated. Maximum-likelihood methods, which assess which of several models of evolution best explain the distribution of form and function data on a phylogenetic tree, show that the two major metriorhynchid subclades underwent different evolutionary modes. In geosaurines, both form and function are best explained as evolving under ‘random’ Brownian motion, whereas in metriorhynchines, the form metrics are best explained as evolving under stasis and the function metric as undergoing a directional change (towards most efficient low-stress piscivory). This suggests that the two subclades were under different selection pressures, and that metriorhynchines with similar skull shape were driven to become functionally divergent.
Quantifying selection and diversity in viruses by entropy methods, with application to the haemagglutinin of H3N2 influenza
Authors: Pan Keyao , Deem Michael W.
Published: May 2011

Many viruses evolve rapidly. For example, haemagglutinin (HA) of the H3N2 influenza A virus evolves to escape antibody binding. This evolution of the H3N2 virus means that people who have previously been exposed to an influenza strain may be infected by a newly emerged virus. In this paper, we use Shannon entropy and relative entropy to measure the diversity and selection pressure by an antibody in each amino acid site of H3 HA between the 1992–1993 season and the 2009–2010 season. Shannon entropy and relative entropy are two independent state variables that we use to characterize H3N2 evolution. The entropy method estimates future H3N2 evolution and migration using currently available H3 HA sequences. First, we show that the rate of evolution increases with the virus diversity in the current season. The Shannon entropy of the sequence in the current season predicts relative entropy between sequences in the current season and those in the next season. Second, a global migration pattern of H3N2 is assembled by comparing the relative entropy flows of sequences sampled in China, Japan, the USA and Europe. We verify this entropy method by describing two aspects of historical H3N2 evolution. First, we identify 54 amino acid sites in HA that have evolved in the past to evade the immune system. Second, the entropy method shows that epitopes A and B on the top of HA evolve most vigorously to escape antibody binding. Our work provides a novel entropy-based method to predict and quantify future H3N2 evolution and to describe the evolutionary history of H3N2.
EXORDIUM-LIKE1 Promotes Growth during Low Carbon Availability in Arabidopsis
Authors: Schröder Florian , Lisso Janina , Müssig Carsten
Published: May 2011

Little is known about genes that control growth and development under low carbon (C) availability. The Arabidopsis (Arabidopsis thaliana) EXORDIUM-LIKE1 (EXL1) gene (At1g35140) was identified as a brassinosteroid-regulated gene in a previous study. We show here that the EXL1 protein is required for adaptation to C- and energy-limiting growth conditions. In-depth analysis of EXL1 transcript levels under various environmental conditions indicated that EXL1 expression is controlled by the C and energy status. Sugar starvation, extended night, and anoxia stress induced EXL1 gene expression. The C status also determined EXL1 protein levels. These results suggested that EXL1 is involved in the C-starvation response. Phenotypic changes of an exl1 loss-of-function mutant became evident only under corresponding experimental conditions. The mutant showed diminished biomass production in a short-day/low-light growth regime, impaired survival during extended night, and impaired survival of anoxia stress. Basic metabolic processes and signaling pathways are presumed to be barely impaired in exl1, because the mutant showed wild-type levels of major sugars, and transcript levels of only a few genes such as QUA-QUINE STARCH were altered. Our data suggest that EXL1 is part of a regulatory pathway that controls growth and development when C and energy supply is poor.
Why the long face? A comparative study of feeding kinematics of two pipefishes with different snout lengths
Authors: Van Wassenbergh S. , Roos G. , Aerts P. , Herrel A. , Adriaens D.
Published: May 2011

This study showed that the mouth of Doryrhamphus dactyliophorus, a species with a relatively long snout, travels a greater distance compared with Doryrhamphus melanopleura, a species with a considerably shorter snout, allowing it to strike at prey that are farther away from the mouth. The long‐snouted species also tended to reach significantly higher linear velocities of the mouth approaching the prey. On the other hand, D. melanopleura needed less time to capture its prey. A striking difference in prey‐capture success was observed between species: D. melanopleura and D. dactyliophorus had a prey‐capture success of 91 and 31%, respectively. The small prey size and the relatively large distance between eyes and prey are potential reasons why directing the mouth accurately to the prey is difficult in D. dactyliophorus, hence possibly explaining the lower prey‐capture success in this long‐snouted species.
Why could passive Immunoglobulin E antibody therapy be safe in clinical oncology?
Authors: Jensen‐Jarolim E. , Singer J.
Published: May 2011

Cite this as: E. Jensen‐Jarolim and J. Singer, Clinical & Experimental Allergy, 2011 (41) 1337–1340.