bluuebunny/crossref_metadata_2025 huggingface dataset:
Spacing and linkage of confined normal faults: Importance of mechanical thickness
Authors: Soliva Roger , Benedicto Antonio , Maerten Laurent
Published: January 2006

In this paper we present the results of the analysis of fault spacing from a population of faults confined to a 4.5 m thick mechanical layer. We demonstrate the control of a discrete layer on the specific geometry of a so‐called “domino‐style” or “bookshelf” fault population. The fault population shows a logarithmic‐normal frequency distribution of fault spacing, with a minimum value of spacing S* (∼0.25 layer thickness), revealing a nearly regular spacing distribution between the “long faults” (i.e., length greater than height), which are confined within the layer. We also observe an upper limit of fault linkage at relay ramp close to the minimum value of spacing S*, after which free overlapping between faults having the same dip direction is allowed. On the basis of field observations, we simulate the quasi‐static displacement‐related Coulomb shear stress perturbation of faults of various aspect ratios (length/height). The models show that on faults that increase in aspect ratio with a constant height (as expected for the confined faults), the horizontal extent of the local stress reduction tends to localize at a constant distance from the fault surface close to S*. For the studied case, the correspondence between the models and the field data suggests that the limited extent of the stress reduction around the confined faults controls fault spacing and fault ability to link at relay ramps. Both field data collection from different scales and modeling suggest that fault spacing in confined fault populations is linearly related to the mechanical layer thickness. We therefore highlight the importance of the thickness of layers confining faults in the evaluation of interaction, linkage and propagation of active fault segments over a broad range of scales.
Effective diffusivity in the middle atmosphere based on general circulation model winds
Authors: Kostrykin S. V. , Schmitz G.
Published: January 2006

The mixing of a passive tracer in the stratosphere and lower mesosphere is studied on the basis of the effective diffusivity, which is obtained in the framework of the tracer‐based coordinate system. This characteristic is proportional to the average diffusion flux over Lagrangian contours and inversely proportional to the mean tracer gradient. The tracer distribution used in the calculation of the effective diffusivity is obtained after integration of the advection‐diffusion equation using general circulation model winds and a new numerical advection scheme with small numerical diffusivity. Using some theoretical and experimental arguments, it is shown that the interpretation of the seasonal variability of the effective diffusivity field cannot be done on the basis of the momentary wind field alone, but some flow history should be taken into account. The climatology of the effective diffusivity for different months is presented up to the lower mesosphere and compared with previous studies. In the stratosphere some new features of the effective diffusivity distribution are obtained. For example, there is a local maximum of the effective diffusivity at midlatitudes of the Northern Hemisphere of the summer middle stratosphere. The effective diffusivity fields in the lower mesosphere show a strong increase of the mean effective diffusivity from the upper stratosphere to the lower mesosphere and the existence of a complex latitudinal structure of the effective diffusivity at mesospheric heights. In the lower mesosphere there is a marked interannual variability during the Southern Hemisphere easterly wind development. A possible explanation for the obtained structure is discussed on the basis of in situ Rossby wave generation and Rossby‐wave‐breaking effects.
Estimating ground conductivity and improving lightning location goodness of fit by compensating propagation effects
Authors: Schueler J. R. , Thomson E. M.
Published: January 2006

Propagation effects were noticed in lightning ground waves received at the five stations of a 10‐km‐baseline time‐of‐arrival lightning location system at Kennedy Space Center, Florida, on 10 September 1992. The ground waves were nonuniformly smoothed, and that caused the tagged points in time on the pulses to be nonuniformly delayed. Lightning location chi‐squares were 2 orders of magnitude worse for ground wave propagation than for line‐of‐sight propagation, but 0.3 of an order of magnitude was recovered by compensating the time tags for propagation effects. Effective ground conductivity, associated time tag delay, effective source height, and station gain were estimated by applying the method of least squares to a nonlinear objective function. The geometric mean ground conductivity was 0.0059 S/m, and the geometric standard deviation was 1.83 for 384 propagation paths of 78 lightning sources, in line with accepted values. The geometric standard deviation of conductivity for a subset of 122 paths, including consecutive lightning sources having nearly identical propagation paths, was 1.86. The geometric standard deviation derived from 68 ratios of consecutive conductivity estimates having nearly identical propagation paths was 1.38; thus the geometric standard deviation of conductivity among paths was 1.71.
Analyzing seasonal temperature trends in forced climate simulations of the past millennium
Authors: Bauer Eva , Claussen M.
Published: January 2006

Temperature observations from the Northern Hemisphere reveal a warming since 1861 which is larger in winter than in summer. Possible explanations for a decline in seasonal spread are discussed using the Earth system model CLIMBER‐2. Simulations forced by natural and anthropogenic factors (Milankovitch forcing, solar variability, volcanism, atmospheric CO2 concentration, deforestation) generate specific seasonal responses. While the Milankovitch forcing increased the millennial seasonal spread, and solar variability and volcanism proved ancillary in reducing the spread on the centennial timescale, the anthropogenic factors appear the primary agents to attenuate the seasonal spread. The climatic effect of the anthropogenic factors is amplified by seasonally varying feedbacks related to the albedo of changing sea‐ice and snow cover.
Comparison of recent modeled and observed trends in total column ozone
Authors: Andersen S. B. , Weatherhead E. C. , Stevermer A. , Austin J. , Brühl C. , Fleming E. L. , de Grandpré J. , Grewe V. , Isaksen I. , Pitari G. , Portmann R. W. , Rognerud B. , Rosenfield J. E. , Smyshlyaev S. , Nagashima T. , Velders G. J. M. , Weisenstein D. K. , Xia J.
Published: January 2006

We present a comparison of trends in total column ozone from 10 two‐dimensional and 4 three‐dimensional models and solar backscatter ultraviolet–2 (SBUV/2) satellite observations from the period 1979–2003. Trends for the past (1979–2000), the recent 7 years (1996–2003), and the future (2000–2050) are compared. We have analyzed the data using both simple linear trends and linear trends derived with a hockey stick method including a turnaround point in 1996. If the last 7 years, 1996–2003, are analyzed in isolation, the SBUV/2 observations show no increase in ozone, and most of the models predict continued depletion, although at a lesser rate. In sharp contrast to this, the recent data show positive trends for the Northern and the Southern Hemispheres if the hockey stick method with a turnaround point in 1996 is employed for the models and observations. The analysis shows that the observed positive trends in both hemispheres in the recent 7‐year period are much larger than what is predicted by the models. The trends derived with the hockey stick method are very dependent on the values just before the turnaround point. The analysis of the recent data therefore depends greatly on these years being representative of the overall trend. Most models underestimate the past trends at middle and high latitudes. This is particularly pronounced in the Northern Hemisphere. Quantitatively, there is much disagreement among the models concerning future trends. However, the models agree that future trends are expected to be positive and less than half the magnitude of the past downward trends. Examination of the model projections shows that there is virtually no correlation between the past and future trends from the individual models.
Evaluating parameterizations of the autoconversion process using a single‐column model and Atmospheric Radiation Measurement Program measurements
Authors: Iacobellis Sam F. , Somerville Richard C. J.
Published: January 2006

A single‐column model is used to evaluate the performance of two types of autoconversion parameterizations. The model results are compared to data collected at the Atmospheric Radiation Measurement Program's Southern U.S. Great Plains site. The model is run over a period covering 2 years (2000–2001), and the results are analyzed for time periods varying from hourly to seasonal. During a relatively short 27‐hour period during March 2000 characterized primarily by shallow frontal clouds, modeled values of cloud liquid water were better simulated using a Manton‐Cotton‐type autoconversion parameterization. However, over longer timescales representing a multitude of different cloud types and meteorological conditions, a Sundqvist‐type parameterization produced better results. Analysis of the model results indicates that the Manton‐Cotton‐type parameterization does better during periods when shallow clouds are present without any overlying clouds, while the Sundqvist‐type parameterization is preferred during periods when high and low clouds coexist. A possible explanation is that precipitation from high clouds may not be represented well by the SCM, thus affecting the precipitation formation rates in any lower clouds. Sensitivity tests using the Manton‐Cotton parameterization indicate that the autoconversion rate is sensitive to the specification of the cloud droplet number concentration (Nc). The single‐column model, as well as many general circulation models, specify Nc as a constant value. However, limited in situ measurements suggest that Nc varies significantly in time. The mean modeled top‐of‐atmosphere cloud radiative forcing during the 2‐year period 2000–2001 differed by 3 W m−2 as the cloud droplet concentration was varied between minimum and maximum values suggested by the in situ measurements. These results imply that model‐produced hydrological cycle and cloud‐radiation interactions could be better modeled using an accurate time‐dependent measure of the cloud droplet concentration.
Tidally driven groundwater flow and solute exchange in a marsh: Numerical simulations
Authors: Wilson Alicia Marie , Gardner Leonard Robert
Published: January 2006

Tidal fluctuations drive groundwater flow in salt marsh sediments. This flow could cause significant chemical exchange across the sediment‐water interface and could affect marsh ecology. Numerical models of a generalized tidal creek and marsh were constructed to calculate flow patterns and solute exchange between the marsh and creek. The governing equation for saturated/unsaturated flow was modified to account for tide‐related changes in total stress. Groundwater flow occurred primarily in the creek bank, even when the marsh platform was inundated at high tide. For marsh sediments with a hydraulic conductivity of 10−4 m s−1, groundwater ages in simulations lasting 60 days were on the order of days near the creek bank and increased to 50–60 days with distance into the marsh. The volume of water that discharged between high and low tide was 0.22–0.31 m3 per meter length of channel, which, for a creek drainage density of 0.012 m−1, corresponds to 10–14 L m−2 d−1. Sediment permeability and capillarity were important controls on flow and groundwater age in the marsh. Sediment compressibility affected groundwater age for compressible sediments representative of mud but not for sediments with lower compressibilities representative of sand. Simulations were relatively insensitive to dispersivity. A comparison of simulation results with other estimates of groundwater exchange from the North Inlet, South Carolina, suggest that tides could drive observed exchange there only if the Pleistocene sands underlying muddy marsh sediments outcrop within the tidal range.
Sensitivity and uncertainty analysis of the recharge boundary condition
Authors: Jyrkama M. I. , Sykes J. F.
Published: January 2006

The reliability analysis method is integrated with MODFLOW to study the impact of recharge on the groundwater flow system at a study area in New Jersey. The performance function is formulated in terms of head or flow rate at a pumping well, while the recharge sensitivity vector is computed efficiently by implementing the adjoint method in MODFLOW. The developed methodology not only quantifies the reliability of head at the well in terms of uncertainties in the recharge boundary condition, but it also delineates areas of recharge that have the highest impact on the head and flow rate at the well. The results clearly identify the most important land use areas that should be protected in order to maintain the head and hence production at the pumping well. These areas extend far beyond the steady state well capture zone used for land use planning and management within traditional wellhead protection programs.
Equilibrium thermodynamics from basin-sampling
Authors: Bogdan Tetyana V. , Wales David J. , Calvo Florent
Published: January 2006

We present a “basin-sampling” approach for calculation of the potential energy density of states for classical statistical models. It combines a Wang-Landau-type uniform sampling of local minima and a novel approach for approximating the relative contributions from local minima in terms of the volumes of basins of attraction. We have employed basin-sampling to study phase changes in atomic clusters modeled by the Lennard-Jones potential and for ionic clusters. The approach proves to be efficient for systems involving broken ergodicity and has allowed us to calculate converged heat capacity curves for systems that could previously only be treated using the harmonic superposition approximation. Benchmarks are also provided by comparison with parallel tempering and Wang-Landau simulations, where these proved feasible.
Ab initio study of optical properties of rhodamine 6G molecular dimers
Authors: Gavrilenko V. I. , Noginov M. A.
Published: January 2006

Equilibrium atomic geometries of rhodamine 6G (R6G) dye molecule dimers are studied using density-functional theory. Electron-energy structure and optical properties of R6G H and J dimers are calculated using the generalized gradient approximation method with ab initio pseudopotentials. Our theory predicts substantial redshifts or blueshifts of the optical absorption spectra of R6G dye molecules after aggregation in J or H dimers, respectively. Predicted optical properties of R6G dimers are interpreted in terms of interatomic and intermolecular interactions. Results of the calculations are discussed in comparison with experimental data.
Incidence of partial charges on ion selectivity in potassium channels
Authors: Huetz Philippe , Boiteux Céline , Compoint Mylène , Ramseyer Christophe , Girardet Claude
Published: January 2006

Potassium channels are membrane proteins known to select potassium over sodium ions at a high diffusion rate. We conducted ab initio calculations on a filter model of KcsA of about 300 atoms at the Hartree-Fock level of theory. Partial charges were derived from the quantum mechanically determined electrostatic potential either with Merz-Kollman or Hinsen-Roux schemes. Large polarization and/or charge transfer occur on potassium ions located in the filter, while the charges on sodium ions remain closer to unity. As a result, a weaker binding is obtained for K+ ions. Using a simplified version of a permeation model based on the concerted-motion mechanism for ion translocation within the single-file ion channel [P. H. Nelson, J. Chem. Phys. 117, 11396 (2002)], we discuss how differences in polarization effects in the adducts with K+ and Na+ can play a role as for ionic selectivity and conductance.
Root-like structure at the nanowire/substrate interface in GaAs nanowires
Authors: Banerjee R. , Bhattacharya A. , Ratan R. , Shah A. P. , Gokhale M. R. , Arora B. M. , Genc A. , Kar S.
Published: January 2006

We report the observation of a root-like structure at the interface between GaAs nanowires and the (100) single-crystal GaAs substrate. These nanowires were grown via the vapor-liquid-solid mechanism using metalorganic vapor phase epitaxy. The root-like structure extends from the base of the nanowires into the substrate and has been investigated in detail using transmission electron microscopy and high-resolution electron microscopy. While the nanowires predominantly exhibit the zinc-blende type diamond cubic structure with the growth axis parallel to ⟨111⟩ and growth twins perpendicular to the growth axis, the root regions have a CdTe type orthorhombic structure that has been reported to occur in GaAs only under high-pressure conditions.
Dispersive-diffusion-controlled distance-dependent recombination in amorphous semiconductors
Authors: Seki Kazuhiko , Wojcik Mariusz , Tachiya M.
Published: January 2006

The photoluminescence in amorphous semiconductors decays according to the power law t−δ at long times. The photoluminescence is controlled by dispersive transport of electrons. The latter is usually characterized by the power α of the transient current observed in the time-of-flight experiments. Geminate recombination occurs by radiative tunneling which has a distance dependence. In this paper, we formulate ways to calculate reaction rates and survival probabilities in the case carriers execute dispersive diffusion with long-range reactivity. The method is applied to obtain tunneling recombination rates under dispersive diffusion. The theoretical condition of observing the relation δ=α∕2+1 is obtained and theoretical recombination rates are compared to the kinetics of observed photoluminescence decay in the whole time range measured.
Enhancement of field emission characteristics of tungsten emitters by single-walled carbon nanotube modification
Authors: Ferrer D. , Tanii T. , Matsuya I. , Zhong G. , Okamoto S. , Kawarada H. , Shinada T. , Ohdomari I.
Published: January 2006

We present a simple method for improving the field emission performance of tungsten-tip electron sources based on single-walled carbon nanotube (SWCNT) modification. By coating a sandwich-like thin film of Al–Fe–Al (with Fe as a catalyst) on a tungsten tip, SWCNTs were synthesized at 600 °C in a chemical vapor deposition (CVD) reactor. The influence of CNT modification on the electron emission characteristics of the emitters was investigated by means of a triode structure. We have found that CNT-modified tungsten tips exhibit low threshold-voltage for electron emission, and improved emission-current stability, compared with nonmodified and Al–Fe–Al-coated needles.
Engineering domain configurations for enhanced piezoelectricity in barium titanate single crystals
Authors: Liu J. J. , Zhou Y. C. , Soh A. K. , Li J. Y.
Published: January 2006

In this letter, we propose a mechanism for enhanced piezoelectricity that takes advantage of both intrinsic crystalline anisotropy of ferroelectric crystal and extrinsic 90° domain switching of ferroelectric variant. The domain configurations we consider here are not clamped, and thus allow domain switching driven by the competition between external electric field and internal depolarization field. The intrinsic and extrinsic piezoelectric responses of barium titanate single crystals under different crystallographic orientations are calculated using an energy minimization theory, where it is observed that the piezoelectric coefficient is significantly enhanced by the 90° domain switching, especially under the small field measurement where the domain wall movement is reversible, which is consistent with recent experimental observations. The optimal crystallographic orientation is also identified.
Nucleation and growth of periodic domains during electric field poling in flux-grown KTiOPO4 observed by atomic force microscopy
Authors: Canalias C. , Wang S. , Pasiskevicius V. , Laurell F.
Published: January 2006

The domain structure of periodically poled KTiOPO4 crystals were studied on both the polar and nonpolar faces utilizing a voltage-modulated atomic force microscope. The measurements give information of domain nucleation, growth, and merging. Two different kind of overpoling behaviors have been observed depending on the magnitude of the applied field.
Influence of frictional conditions of microrubbing on pretilt angle of homeotropic liquid crystal cells
Authors: Honma Michinori , Hirata Kensuke , Nose Toshiaki
Published: January 2006

Polyimide films for a homeotropic alignment are treated by a microrubbing process using a tiny metal ball (1–4mm diameter). During the microrubbing, a vertical load and frictional force are simultaneously measured. Pretilt angles of fabricated liquid crystal cells are determined by measuring retardations using a polarizing microscope. Relationships between the pretilt angle and the frictional force or a frictional work are investigated. Controllability of the pretilt angles in side- and main-chain-type polyimides is discussed. Microscopic mechanism of the decrease of the pretilt angle by the rubbing treatment is discussed and the insight into the roles of the side and main chain is described.
Skin wrinkles of the sire adversely affect Merino and halfbred pelt characteristics and other production traits
Authors: Scobie D. R. , Young S. R. , O'Connell D. , Eythorsdottir E.
Published: January 2006

The wrinkles on the skin of Merino sheep and related breeds are retained during leather processing, and the skins are known as ‘ribby pelts’ in the leather trade. Merino sires with either no skin wrinkles (smooth, n = 7) or excessive wrinkles (ribby, n = 7) were allocated at random to mating groups of 22 Merino ewes mixed with 22 Romney ewes. The progeny of ribby sires were more ribby at docking (P<0.001), at shearing (P<0.001), in the fellmongery (P = 0.001) and as pickled pelts (P<0.001). Merino progeny were more ribby than Merino × Romney (halfbred) progeny at all stages. When professionally graded as pickled pelts, smooth-sired progeny produced more pelts without ribs in both Merino (5% v. 0%) and halfbreds (69% v. 38%) than ribby-sired progeny. Wool samples collected at 7.5 months of age were not significantly different between sire groups in mean fibre diameter (P = 0.27) or staple length (P = 0.60) but they were different in standard deviation of fibre diameter (P = 0.003). Liveweight was consistently greater in the progeny of smooth sires, although this difference did not reach significance until the progeny attained a mean liveweight of 28 kg for Merinos and 32 kg for halfbreds (P = 0.016). Breed differences were observed in other traits and these are discussed. Interestingly, there were few significant sire type breed interactions, the exceptions being yield of clean wool (P<0.001), standard deviation of fibre diameter (P = 0.003) and an additional pelt trait referred to as pinhole score (P = 0.003). In summary, choosing sires without skin wrinkles can improve pelt quality, wool quality and liveweight of Merino and halfbred progeny.
Effects of grain or hay supplementation on the chewing behaviour and stability of rumen fermentation of dairy cows grazing perennial ryegrass-based pasture in spring
Authors: Williams Y. J. , Wales W. J. , Doyle P. T. , Egan A. R. , Stockdale C. R.
Published: January 2006

Cows grazing highly digestible pasture in early spring can have very low rumen fluid pH that can negatively impact on the efficiency of microbial digestion. In this experiment, cows in early lactation grazed perennial ryegrass (Lolium perenne L.)-based pasture alone at low or high allowances, or at a low allowance supplemented with either a cereal grain pellet, a chopped hay cube or a cube containing cereal grain and chopped hay to determine the effects of the addition of neutral detergent fibre as hay on chewing behaviour and stability of rumen fermentation. The hypotheses tested were that: (i) supplementing high digestibility ryegrass pasture with pelleted cereal grain would increase the proportion of the day that the pH of rumen fluid was below 6.0 and would decrease the rate of degradation of neutral detergent fibre in pasture and hay; and (ii) the inclusion of chopped hay with the cereal grain supplement in cubes would reduce the proportion of the day that the rumen fluid pH was below 6.0 and restore the rate of degradation of neutral detergent fibre in pasture and hay to that in unsupplemented cows. Rumen fluid pH was highest (P<0.05) in cows fed a chopped hay cube and lowest (P<0.05) in cows fed a cube containing cereal grain and chopped hay, with no significant (P>0.05) difference between those fed pasture only or cereal grain pellets. The introduction of grain, with or without hay, did not substantially alter the pattern or magnitude of changes in rumen fluid pH, but did reduce (P<0.05) the rate of degradation of neutral detergent fibre in pasture (5.3 v. 7.6%/h) and hay (2.7 v. 5.0%/h) in the rumen. Rumen degradation rates of pasture dry matter and neutral detergent fibre were not improved by adding chopped hay. Total volatile fatty acid concentrations in rumen fluid were highest (P<0.05) on the high pasture allowance treatment and lowest (P<0.05) on the low pasture allowance and the chopped hay cube treatments. Supplementation with grain reduced (P<0.05) the proportion of acetate and increased (P<0.05) the proportion of propionate in total volatile fatty acids. There were no significant (P>0.05) effects of dietary treatment on time spent grazing or on rate of biting while grazing. Cows in treatments receiving grain supplements (532 min) and those in the high pasture allowance treatment (566 min) spent more (P<0.05) time ruminating than those in the low pasture allowance (415 min) and chopped hay cube (465 min) treatments. The relative contributions of low pH and of starch to the reduction in rates of dry matter and neutral detergent fibre degradation in the rumen cannot be determined from this experiment, however, it is likely that both factors contribute to a relative increase in the metabolic activity of non-cellulolytic microorganisms.
Targeting key perceptions when planning and evaluating extension
Authors: Llewellyn R. S. , Pannell D. J. , Lindner R. K. , Powles S. B.
Published: January 2006

Early identification of farmer perceptions influencing particular farm management decisions provides the opportunity to more effectively focus investment in research and extension. A survey-based study examining the adoption of integrated weed management by Western Australian grain growers was used to demonstrate how identification of key farmer perceptions can help to guide research and extension priorities. It was found that the adoption of integrated weed management practices was influenced by grower perceptions of herbicide resistance-related factors and of the efficacy and economic value of integrated weed management practices in the farming system. However, there were generally no significant differences between the perceptions of practice efficacy held by users and non-users of the integrated weed management practices. As initial perceptions of efficacy were generally consistent with local field experience, it was expected that extension would not have a major influence on this variable. Consistent with this, participation by growers in a workshop based on the bio-economic farming systems model, resistance integrated management (RIM), did not result in changes in perceptions of practice efficacy. However, changes in the perceived short-term economic value of some weed management practices did occur where the broader value of practices to the farming system, not necessarily relating to weed control, could be demonstrated. This also led to more growers deciding to adopt those practices. For example, intended wheat seeding rates were shown to increase by 5 kg/ha as a result of participation in the extension activity. Determining the perceptions influencing adoption, and then identifying the major learning opportunities can be valuable in focusing research and extension. Measures of perceptions also allow learning to be evaluated. In the case study of adoption of the integrated weed management practices in WA, it seems that emphasis on developing and extending the farming-systems impacts beyond just weed and resistance management is likely to be more effective than focusing on the efficacy of the practices for controlling major weeds.
Investigating the interaction between body condition at calving and pre-calving energy and protein nutrition on the early lactation performance of dairy cows
Authors: Stockdale C. R.
Published: January 2006

The experiment was an investigation into the interaction between body condition at calving and the provision of additional dietary energy or protein to a total mixed ration (TMR) in late gestation on milk production and indices of reproductive performance. Seventy-two Holstein–Friesian multiparous cows (12 per treatment) were fed to achieve target body condition scores (BCS) of either 4 (3.5–4.5) or 6 (5.5–6.5) units by 1 month before they calved (July). They were individually fed 1 of 3 diets during the last 26 (s.d. ± 7.4) days before calving date (mean of 19 August; s.d. ± 9.7). The 3 diets were (1) a TMR containing maize silage, barley grain, canola meal and hay, fed at 1.5% of liveweight (control diet), (2) the TMR plus 3.5 kg DM of wheat-based pellets (energy diet), and (3) the TMR plus 3.1 kg DM of soyabean meal (protein diet). Cows grazed highly digestible pasture after calving at pasture allowances of about 35 kg DM/cow.day, and were supplemented with 6 kg DM of cereal grain-based pellets per day. Cows were fed this diet for an average of about 10 weeks, from calving until the start of mating at the end of October. The provision of additional dietary energy and protein before calving did not affect post-partum production, and there were no interactions with body condition. On average, the BCS 6 cows were 111 kg heavier (P<0.05), and were 1.8 units of body condition higher (P<0.05), than the BCS 4 cows. The thin cows maintained body condition during the month before parturition while the fat cows lost condition. The cows offered additional protein improved their body condition (+0.07 units) during this time, while the cows in the other 2 dietary treatments lost condition (–0.10 units). Average daily rumen fluid pH was lowest in the cows fed the additional energy. Blood urea and rumen fluid ammonia concentrations were increased markedly by feeding the protein diet. In comparison with cows offered the control and energy diets, the cows offered additional protein had the highest (P<0.05) urine pH levels (6.24 v. 5.64 and 5.59 for the protein, control and energy diets, respectively), the lowest (P<0.05) blood serum concentrations of calcium at calving (1.74 v. 2.06 and 1.99 mmol/L for the protein, control and energy diets, respectively), and tended to have more milk fever and retained foetal membranes. Regression analysis indicated that the response to improving BCS at calving was 1.1 kg milk per additional BCS at calving (P<0.05), and the fatter cows produced milk with a higher (P<0.05) milk fat concentration (3.46 v. 3.07%) than the thinner cows. There was no effect (P>0.05) of treatment on days to first ovulation or in-calf rates although only about 80% of cows conceived during the 12-week mating period.
Intrinsic backbone preferences are fully present in blocked amino acids
Authors: Avbelj Franc , Grdadolnik Simona Golic , Grdadolnik Joze , Baldwin Robert L.
Published: January 2006

The preferences of amino acid residues for φ,ψ backbone angles vary strikingly among the amino acids, as shown by the backbone angle φ found from the
3
J(H
α
,H
N
) coupling constant for short peptides in water. New data for the
3
J(H
α
,H
N
) values of blocked amino acids (dipeptides) are given here. Dipeptides exhibit the full range of coupling constants shown by longer peptides such as GGXGG and dipeptides present the simplest system for analyzing backbone preferences. The dipeptide coupling constants are surprisingly close to values computed from the coil library (conformations of residues not in helices and not in sheets). Published coupling constants for GGXGG peptides agree closely with dipeptide values for all nonpolar residues and for some polar residues but not for X = D, N, T, and Y, which are probably affected by polar side chain–backbone interactions in GGXGG peptides. Thus, intrinsic backbone preferences are already determined at the dipeptide level and remain almost unchanged in GGXGG peptides and are strikingly similar in the coil library of conformations from protein structures. The simplest explanation for the backbone preferences is that backbone conformations are strongly affected by electrostatic dipole–dipole interactions in the peptide backbone and by screening of these interactions with water, which depends on nearby side chains. Strong backbone electrostatic interactions occur in dipeptides. This is shown by calculations both of backbone electrostatic energy for different conformers of the alanine dipeptide in the gas phase and by electrostatic solvation free energies of amino acid dipeptides.
Fat and protein metabolism in growing steers fed either grass silage or dried grass
Authors: Greathead H. M. R. , Dawson J. M. , Craigon J. , Sessions V. A. , Scollan N. D. , Buttery P. J.
Published: January 2006

Cattle fed grass silage diets have been reported to have high carcass fat:protein ratios. The effect of grass silage and dried grass diets, fed at different levels of intake to ensure a range of equivalent metabolisable energy intakes (MEI) from 1·1×metabolisable energy requirement for maintenance toad libitum, on fat and protein metabolism in twenty-four Hereford×Friesian steers was investigated. After about 84d of dietary treatment rates of whole-body fat and protein metabolism were measured, as were rates of lipogenesis in omental, perirenal and subcutaneous adipose tissue. Carcass composition was determined. Animals fed silage had greater (P<0·001) carcass fat:protein ratios than animals fed dried grass at equivalent levels of MEI. Animals fed silage had lower (P<0·001) rates of protein gain. Rates of leucine entry and oxidation were lower (P<0·001) in animals fed silage, but there was no dietary difference in the rate of whole-body protein synthesis. There was no dietary difference in the rate of carcass fat gain, but rates of lipogenesis in perirenal adipose tissue were significantly (P=0·007) higher in animals fed silage. There was no dietary difference in the rate of palmitate and glycerol entry or palmitate oxidation. There were no interactions between MEI and diet, indicating that increments of energy were utilised with the same efficiency from both diets. It was concluded that the high carcass fat:protein ratios of young growing steers was due to limited rates of protein accretion and not to elevated rates of carcass fat accretion.
L-Arginine attenuates xanthine oxidase and myeloperoxidase activities in hearts of rats during exhaustive exercise
Authors: Lin Wan-Teng , Yang Suh-Ching , Tsai Shiow-Chwen , Huang Chi-Chang , Lee Ning-Yuean
Published: January 2006

The present study was to investigate the effects of l-arginine (l-Arg) supplementation on cardiac oxidative stress and the inflammatory response in rats following acute exhaustive exercise on a treadmill. Rats were randomly divided into four groups: sedentary control (SC); SC with l-Arg treatment (SC+Arg); exhaustive exercise (E); exhaustive exercise with l-Arg treatment (E+Arg). Rats in groups SC+Arg and E+Arg received a 2% l-Arg diet. Rats in groups E and E+Arg performed an exhaustive running test on a treadmill at a final speed of 30m/min, 10% grade, at approximately 70–75% VO2max. The results showed a significant increase in cardiac xanthine oxidase (XO) and myeloperoxidase activities and membrane lipid peroxidation endproduct (malondialdehyde; MDA) levels of exercised rats compared with SC rats. The increased cardiac XO activity and MDA levels in exercised rats were significantly decreased in exercised rats supplemented with l-Arg. Myocardial GSSG content increased whereas the GSH:GSSG ratio was depressed in exercised rats compared with SC rats. Cardiac GSSG levels significantly decreased, whereas total glutathione, GSH and the GSH:GSSG ratio increased in exercised rats supplemented with l-Arg compared with exercised rats. The activities of creatinine kinase (CK) and lactate dehydrogenase (LDH), and lactate, uric acid, and nitrite and nitrate levels in the plasma significantly increased in exercised rats compared with SC rats. The activities of plasma CK and LDH were significantly decreased in l-Arg-supplemented plus exercised rats compared with exercised rats. These findings suggest that l-Arg supplementation reduces the oxidative damage and inflammatory response on the myocardium caused by exhaustive exercise in rats.
Evidence of negative energy balance using doubly labelled water in elite Kenyan endurance runners prior to competition
Authors: Fudge Barry W. , Westerterp Klaas R. , Kiplamai Festus K. , Onywera Vincent O. , Boit Michael K. , Kayser Bengt , Pitsiladis Yannis P.
Published: January 2006

Previous studies have found Kenyan endurance runners to be in negative energy balance during training and prior to competition. The aim of the present study was to assess energy balance in nine elite Kenyan endurance runners during heavy training. Energy intake and expenditure were determined over 7d using weighed dietary intake and doubly labelled water, respectively. Athletes were on average in negative energy balance (mean energy intake 13 241 (SD 1330) kJ/dv. mean energy expenditure 14 611 (SD 1043) kJ/d;P=0·046), although there was no loss in body mass (mean 56·0 (SD 3·4) kgv. 55·7 (SD 3·6) kg;P=0·285). The calculation of underreporting was 13; (range −24 to +9%) and almost entirely accounted for by undereating (9% (range −55 to +39%)) as opposed to a lack of significant underrecording (i.e. total water intake was no different from water loss (mean 4·2 (SD 0·6) l/dv. 4·5 (SD 0·8) l/d;P=0·496)). Fluid intake was modest and consisted mainly of water (0·9 (SD 0·5) l/d) and milky tea (0·9 (SD 0·3) l/d). The diet was high in carbohydrate (67·3 (SD 7·8) %) and sufficient in protein (15·3 (SD 4·0) %) and fat (17·4 (SD 3·9) %). These results confirm previous observations that Kenyan runners are in negative energy balance during periods of intense training. A negative energy balance would result in a reduction in body mass, which, when combined with a high carbohydrate diet, would have the potential in the short term to enhance endurance running performance by reducing the energy cost of running.
Fish-bone peptide increases calcium solubility and bioavailability in ovariectomised rats
Authors: Jung Won-Kyo , Lee Bae-Jin , Kim Se-Kwon
Published: January 2006

Fish-bone peptides (FBP) with a high affinity to Ca were isolated using hydroxyapatite affinity chromatography, and FBP II with a high ratio of phosphopeptide was fractionated in the range of molecular weight 5·0–1·0kDa by ultramembrane filtration.In vitrostudy elucidated that FBP II could inhibit the formation of insoluble Ca salts in neutral pH.In vivoeffects of FBP II on Ca bioavailability were further examined in the ovariectomised rat. During the experimental period, Ca retention was increased and loss of bone mineral was decreased by FBP II supplementation in ovariectomised rats. After the low-Ca diet, the FBP II diet, including both normal level of Ca and vitamin D, significantly decreased Ca loss in faeces and increased Ca retention compared with the control diet. The levels of femoral total Ca, bone mineral density, and strength were also significantly increased by the FBP II diet to levels similar to those of the casein phosphopeptide diet group (no difference;P>0·05). In the present study, the results proved the beneficial effects of fish-meal in preventing Ca deficiency due to increased Ca bioavailability by FBP intake
A comparison of the effect of forage type and level of feeding on the digestibility and gastrointestinal mean retention time of dry forages given to cattle, sheep, ponies and donkeys
Authors: Pearson R. A. , Archibald R. F. , Muirhead R. H.
Published: January 2006

Four cattle, sheep, ponies and donkeys were fed dehydrated lucerne, early-cut hay, later-cut hay or barley straw in a Latin square-based design for four periods of 35d. In the first sub-period animals were fed the dietsad libitum(1–21d) and in the second sub-period they were fed the same diet restricted to 0·75 ofad libitumintake (days 22–35). Measurements of forage intake, apparent digestibilities and gastrointestinal mean retention times (MRT) were made in the last 7d of each sub-period. Differences between species in voluntary DM intake (VDMI; g/kg live weight LW)0·75and g/LW) were greatest on the lucerne and least on barley straw. Cattle VDMI (g/kg LW0·75) compared with intake of the other species was > ponies > sheep > donkeys on lucerne. On barley straw VDMI (g/kg LW0·75) of cattle compared with intake of the other species was = donkey = ponies > sheep. VDMI of hays were intermediate between the lucerne and straw forages. Apparent digestibilities of DM, organic matter (OM), neutral-detergent fibre (NDF) and acid-detergent fibre (ADF) of the lucerne and hays were higher in the ruminants than in the equids. Effect of feeding level was not significant. Gastrointestinal MRT was shorter in the equids than in the ruminants. On straw diets donkeys showed similar apparent digestibilities of feed components to those of the cattle, whilst apparent digestibility of the straw diet by the ponies was lowest. Results are discussed in relation to evolutionary differences in feeding and digestion strategy associated with fore- or hind-gut fermentation in ruminants and equids.
Distinct Roles of PI(3,4,5)P3during Chemoattractant Signaling inDictyostelium: A Quantitative In Vivo Analysis by Inhibition of PI3-Kinase
Authors: Loovers Harriët M. , Postma Marten , Keizer-Gunnink Ineke , Huang Yi Elaine , Devreotes Peter N. , van Haastert Peter J.M.
Published: January 2006

The role of PI(3,4,5)P3in Dictyostelium signal transduction and chemotaxis was investigated using the PI3-kinase inhibitor LY294002 and pi3k-null cells. The increase of PI(3,4,5)P3levels after stimulation with the chemoattractant cAMP was blocked >95% by 60 μM LY294002 with half-maximal effect at 5 μM. This correlated well with the inhibition of the membrane translocation of the PH-domain protein, PHcracGFP. LY294002 did not reduce cAMP-mediated cGMP production, but significantly reduced the cAMP response up to 75% in wild type and completely in pi3k-null cells. LY294002-treated cells were round, not elongated as control cells. Interestingly, cAMP induced a time and dose-dependent recovery of cell elongation. These elongated LY294002-treated wild-type and pi3k-null cells exhibited chemotactic orientation toward cAMP that is statistically identical to chemotactic orientation of control cells. In control cells, PHcrac-GFP and F-actin colocalize upon cAMP stimulation. However, inhibition of PI3-kinases does not affect the first phase of the actin polymerization at a wide range of chemoattractant concentrations. Our data show that severe inhibition of cAMP-mediated PI(3,4,5)P3accumulation leads to inhibition of cAMP relay, cell elongation and cell aggregation, but has no detectable effect on chemotactic orientation, provided that cAMP had sufficient time to induce cell elongation.
Assortment of Phosphatidylinositol 3-Kinase Complexes—Atg14p Directs Association of Complex I to the Pre-autophagosomal Structure inSaccharomyces cerevisiae
Authors: Obara Keisuke , Sekito Takayuki , Ohsumi Yoshinori
Published: January 2006

In the yeast Saccharomyces cerevisiae, two similar phosphatidylinositol 3-kinase complexes (complexes I and II) function in distinct biological processes, complex I in autophagy and complex II in the vacuolar protein sorting via endosomes. Atg14p is only integrated into complex I, likely facilitating the function of complex I in autophagy. Deletion analysis of Atg14p revealed that N-terminal region containing the coiled-coil structures was essential and sufficient for autophagy. Atg14p localized to pre-autophagosomal structure (PAS) and vacuolar membranes, whereas Vps38p, a component specific to complex II, localized to endosomes and vacuolar membranes. Vps34p and Vps30p, components shared by the two complexes, localized to the PAS, vacuolar membranes, and several punctate structures that included endosomes. The localization of these components to the PAS was Atg14p dependent but not dependent on Vps38p. Conversely, localization of these proteins to endosomes required Vps38p but not Atg14p. Vps15p, regulatory subunit of the Vps34p complexes, localized to the PAS, vacuolar membranes, and punctate structures independent of both Atg14p and Vps38p. Together, these results indicate that complexes I and II function in distinct biological processes by localizing to specific compartments in a manner mediated by specific components of each complex, Atg14p and Vps38p, respectively.
The F-Box Protein Dia2 Regulates DNA Replication
Authors: Koepp Deanna M. , Kile Andrew C. , Swaminathan Swarna , Rodriguez-Rivera Veronica
Published: January 2006

Ubiquitin-mediated proteolysis plays a key role in many pathways inside the cell and is particularly important in regulating cell cycle transitions. SCF (Skp1/Cul1/F-box protein) complexes are modular ubiquitin ligases whose specificity is determined by a substrate-binding F-box protein. Dia2 is a Saccharomyces cerevisiae F-box protein previously described to play a role in invasive growth and pheromone response pathways. We find that deletion of DIA2 renders cells cold-sensitive and subject to defects in cell cycle progression, including premature S-phase entry. Consistent with a role in regulating DNA replication, the Dia2 protein binds replication origins. Furthermore, the dia2 mutant accumulates DNA damage in both S and G2/M phases of the cell cycle. These defects are likely a result of the absence of SCFDia2activity, as a Dia2 ΔF-box mutant shows similar phenotypes. Interestingly, prolonging G1-phase in dia2 cells prevents the accumulation of DNA damage in S-phase. We propose that Dia2 is an origin-binding protein that plays a role in regulating DNA replication.
The Private History of International Law
Authors: Mills Alex
Published: January 2006

The purpose of this article is to address two related false assumptions, or myths. The first is an assumption of public international law. It is the myth that the history of international law is one of progressive expansion, of increasing concern in public international law with matters traditionally considered private or internal to States, and that this expansion is a relatively recent phenomenon.1The second is an assumption of private international law. It is the myth that private international law is not actually international, as it is essentially and necessarily a part of the domestic law of States.2These assumptions, taken together, constitute the myth that public and private international law are discrete, distinct disciplines, with independent, parallel histories. This article addresses these myths through an analysis of the role played by international law theory in the history of private international law.