bluuebunny/crossref_metadata_2025 huggingface dataset:
Korean red ginseng attenuates hypercholesterolemia‐enhanced platelet aggregation through suppression of diacylglycerol liberation in high‐cholesterol‐diet‐fed rabbits
Authors: Hwang Seock‐Yeon , Son Dong Ju , Kim Il‐Woong , Kim Dong‐Man , Sohn Sang‐Hyun , Lee Jung‐Jin , Kim Si‐Kwan
Published: April 2008

Intake of Korean red ginseng (KRG, ginseng Radix rubra), rich in glycosylated saponins (ginsenosides), has been known to inhibit platelet aggregation in the normocholesterolemic condition. However, it is unclear whether KRG can attenuate hypercholesterolemia‐enhanced platelet aggregation. This study examined whether the daily consumption of a KRG‐water extract (WE) could prevent the hypercholesterolemia‐enhanced platelet aggregation and progression of hypercholesterolemic atherosclerosis. KRG‐WE administration (200 mg/kg/day) for 8 weeks potently inhibited the platelet aggregation induced by low doses of agonists (0.5 µg/mL collagen and 0.025 unit/mL thrombin), whereas it weakly reduced the blood‐cholesterol levels and formation of atheromatous lesions. In further investigation, KRG‐WE significantly suppressed collagen‐induced 1,2‐diacylglycerol liberation, but had no significant effect on arachidonic acid liberation. Taken together, it can be suggested that the antiplatelet effect of KRG‐WE may, at least partly, be due to the inhibition of 1,2‐diacylglycerol generation rather than regulation of blood lipid levels. In conclusion, daily consumption of KRG‐WE could be a useful alternative measure for the prevention of thrombus and atheroma formation in hypercholesterolemia. Copyright © 2008 John Wiley & Sons, Ltd.
Robust design for multiple dynamic quality characteristics using data envelopment analysis
Authors: Tong Lee‐Ing , Wang Chung‐Ho , Tsai Chih‐Wei
Published: May 2008

The Taguchi method is extensively adopted in various industries to continuously improve product design in response to customer requirements. The dynamic system of the Taguchi method is frequently implemented to design products with flexible applications. However, Taguchi's dynamic system can be employed only for individual quality characteristic, and the relationship between the quality characteristic and the signal factor is assumed to be linear. Because of these restrictions, Taguchi's dynamic system is ineffective for multiple quality characteristics or when the quality characteristic has a nonlinear relationship with the signal factor. This study describes a novel procedure for optimizing a dynamic system based on data envelopment analysis. The proposed procedure overcomes the limitations of Taguchi's dynamic system. Two cases are analyzed to demonstrate the effectiveness of the proposed procedure. The results show that the proposed procedure can enhance multiple dynamic quality characteristics. Copyright © 2008 John Wiley & Sons, Ltd.
Shifts in sauger spawning locations after 40 years of reservoir ageing: influence of a novel delta ecosystem in the Missouri River, USA
Authors: Graeb Brian D. S. , Willis David W. , Spindler Bryan D.
Published: April 2008

To determine how reservoir ageing affects sauger Sander canadense spawning locations in Lewis and Clark Reservoir, we quantified riverine habitat and determined sauger spawning locations during recent years (2003–2004) and compared these results to historic (1950–1966) habitat conditions and spawning locations. The riverine habitat above the reservoir, which was historically homogeneous, has developed into two distinct areas: the upstream remnant river reach, characterized by a distinct main channel, and cold and clear water from the hypolimnetic discharge from the upstream reservoir, and the downstream delta section, which has abundant side channels and backwater areas and is warmer and more turbid water than the remnant reach. Sauger spawning locations have shifted markedly in the last 50 years. Sauger historically spawned in the upper reaches of this system, near Fort Randall Dam. However, in 2003, we found that sauger spawned in the lower delta reach and avoided the remnant reach. This shift likely occurred concomitantly with the development of the novel delta habitat. The delta likely functions more similarly to the historic remnant reach of this system (warmer temperature, turbidity, active meandering, complex habitats, etc.), indicating that sauger prefer to spawn in areas with historic riverine function. Thus, future management activities intended to enhance sauger populations should focus on the restoration of riverine function, such as that provided by emerging reservoir deltas, which may mimic pre‐impoundment conditions on the Missouri River. Copyright © 2008 John Wiley & Sons, Ltd.
Computational fluid dynamics modelling of forebay hydrodynamics created by a floating juvenile fish collection facility at the Upper Baker River Dam, Washington
Authors: Khan Liaqat A. , Roy Elizabeth W. , Rashid Mizan
Published: April 2008

The Upper Baker River Dam utilizes a combination of a floating surface collector (FSC) and a guide net to facilitate the downstream migration of anadromous juvenile fish. The FSC generates attraction currents by withdrawing water from the forebay, upstream of the guide net. The withdrawn water is discharged at the rear of the FSC by two pumps. A three‐dimensional (3D) computational fluid dynamics (CFD) model of the forebay of the dam is presented in this paper. The objective was to investigate forebay hydrodynamics generated by the FSC and operation of the powerhouse. The CFD model, consisting of approximately one million computational cells, was validated against field data. Model results were analyzed, using a recently proposed strain–velocity–pressure (SVP) hypothesis, to identify hydrodynamic cues responsible for attracting juvenile fish to the FSC. The CFD model indicates that the FSC pumps generated high velocity jets dominate the circulation pattern downstream of the guide net. Upstream of the guide net, the velocities are weak, except in the region impacted by attraction currents. The sweeping and normal velocities on the guide net are smaller than those suggested by regulatory agencies for designing screens at juvenile fish collection facilities. Copyright © 2008 John Wiley & Sons, Ltd.
Hydrological changes and ecological impacts associated with water resource development in large floodplain rivers in the Australian tropics
Authors: Leigh Catherine , Sheldon Fran
Published: April 2008

The majority of rivers in the Australian tropics possess near‐natural flow regimes and are an ecological asset of global significance. We examined flow variability in large floodplain rivers in the Gulf of Carpentaria, northern Australia, and the potential ecological impacts of future water resource development (WRD). Flow metrics based on long‐term records were used to classify flow regimes and predict hydrological drivers of ecological function. Flow regimes of selected rivers were then compared with those simulated for pre‐ and post‐WRD flows in the Darling River, a highly modified river in Australia's south‐east. Generally, rivers were classified as typically ‘tropical’ (more permanent, regular flows) or ‘dryland’ (more ephemeral, with greater flow variability). In addition, all rivers displayed wet–dry seasonality associated with changes in flow magnitude or number of zero‐flow days. We propose that these features (flow permanence and regularity; flow variability and absence; wet–dry seasonality) are the key hydrological drivers of biodiversity and ecological function in the floodplain rivers of Australia's north. In terms of WRD, inter‐annual flow variability was predicted to increase or decrease depending on rivers' natural flow regimes, specifically their tendency toward lower or higher flow magnitudes. Either outcome is expected to have adverse effects on the biodiversity and ecological function of these relatively pristine rivers and floodplain habitats. In particular, reduced and homogenized habitat, loss of life‐history cues, inhibited dispersal and shifts in community composition, as a result of WRD, threaten the ecological integrity of rivers adapted to the three hydrological drivers above. These findings serve as a caution for careful consideration of WRD options for rivers in the Australian tropics and for those with similar flow regimes the world over. Copyright © 2008 John Wiley & Sons, Ltd.
Influence of the flood regime on the reproduction of fish species with different reproductive strategies in the Cuiabá River, Upper Pantanal, Brazil
Authors: Bailly D. , Agostinho A. A. , Suzuki H. I.
Published: April 2008

This study evaluated the influence of the flood regime of the Cuiabá River on the reproductive dynamics of fish species with different reproductive strategies. Sampling was carried out at ten sites in the basin, between March 2000 and April 2004. The reproductive strategies evaluated were long‐distance migrant (LM), short‐distance migrant (SM), sedentary with parental care (PC) and sedentary or SM with internal fertilization (IF). Period, duration and intensity of floods were the flooding attributes considered. Duration and time of spawning were evaluated using the index of reproductive activity (IRA), and inferences concerning reproductive allocation were based on the analysis of gonad weight. Reproductive success was evaluated based on the annual catch of young‐of‐the‐year of each species. Reproductive dynamics and flood regime were closely correlated; the reproductive peaks of fishes using all four strategies always preceded flood peaks. Intense floods favoured gonadal development of LM and PC, but were less important for IF. In relation to juvenile survival, the occurrence of floods appeared to be crucial for the strategies of LM, PC and IF, because such floods increased fish survival in the period of initial development. In contrast, SM appeared to be less dependent on floods for reproduction. These results indicate that, except for SM, floods have an important role in the recruitment of species using other reproductive strategies, and influence spawning success as well as juvenile survival. Copyright © 2008 John Wiley & Sons, Ltd.
Estimation of solid‐liquid ratios in bulk fats and emulsions by pulsed nuclear magnetic resonance
Authors: van Boekel M. A. J. S.
Published: May 2008

Several pulsed nuclear magnetic resonance (NMR) methods were evaluated to estimate the solid fat content of fats and oil‐in‐water emulsions. The methods were checked with samples of paraffin oil or triolein containing known quantities of crystalline tristearate. A method based on the signal of solid fat (with use of a correction factor, the “f‐factor”) was rejected in this work for general use. Correct results were obtained with methods that used only the signal of the liquid phase. With emulsions, disturbances could arise due to the surfactant present and to possible solubilization of water in the oil phase, presumably by monoglycerides. Without these disturbances, solid fat content in emulsions could be estimated as in bulk fats, after correction of the liquid phase signal for the contribution of protons from the aqueous phase. The signal from fat crystals inside emulsion droplets differed from that of crystals of the same fat in bulk, which may have been due to difference in crystal size but not to difference in crystal modification. Measurements on natural cream showed that disturbances were also possible in this type of emulsion.
Determination of TBA number by high performance liquid chromatography
Authors: Kakuda Y. , Stanley D. W. , van de Voort F. R.
Published: May 2008

A high performance liquid chromatographic (HPLC) method for the quantitation of malonaldehyde in aqueous distillates was developed. Compared with the standard TBA test, the HPLC method was faster, and less affected by side feactions. A total of 5 min was necessary to assay each distillate and only malonaldehyde was detected. The standard curves were reproducible and standards were stable for up to 6 days. The HPLC method could detect malonaldehyde levels ranging from 1×10−11 to 4×10−11 mol/10µL and either peak height or peak area could be used to quantitate the malonaldehyde concentration. The coefficient of determination between absorbance values determined by the TBA test and peak heights determined by HPLC was 0.946. Twenty‐one freeze‐dried chicken samples with TBA numbers ranging from 3.93 to 16.6 were used for this correlation.
Civil Rights Legislation and the Housing Status of Black Americans: Evidence from Fair Housing Audits and Segregation Indices
Authors: Reed Veronica M.
Published: April 2008

The Fair Housing Act of 1968 made discrimination against minorities in the sale or rental of housing illegal. Twenty years later the Act's coverage was expanded and its enforcement mechanisms strengthened in response to pressure from fair housing advocates and evidence of continued segregation and discrimination. Segregation indices and fair housing audits provide measures of the extent and nature of residential segregation and housing discrimination. High levels of residential segregation suggest that housing discrimination exists, and audits give a direct measure of the incidence of discrimination. To date, housing audits consistently show that black auditors encounter discriminatory treatment in the housing search process. Whether the strengthened enforcement mechanisms of the Act will have a substantial impact on housing market discrimination and, in turn, residential segregation, remains to be seen.
The Role of Housing Vouchers in Baltimore City, Maryland
Authors: Ards Sheila
Published: April 2008

In Baltimore City, the relative well-being of black and white families using Section 8 housing vouchers versus Section 8 housing certificates is compared. Logistic regression is used to examine whether the social and economic characteristics of a regional planning district play a significantly different role in the likelihood that a district will have voucher or certificate recipients. A second analysis examines the average monthly rent paid by blacks and whites for housing in the certificate and voucher programs. The results suggest that whites receive greater economic benefits in the voucher program than in the certificate program while blacks do not.
Studies of the phospholipids, glycolipids and sterols of wheat endosperm
Authors: McKillican Mary E.
Published: April 2008

The phospholipid‐glycolipid mixture, isolated chromatographically from the 舠free舡 (hexane soluble) and 舠bound舡 (hexane insoluble, water‐saturated butanol extractable) lipid of wheat endosperm, was fractionated by column and thinlayer silicic acid chromatography. The components were identified by hydrolysis followed by thin‐layer or paper chromatography of the products. They included a sterol‐containing glycolipid, hitherto unreported in wheat. The fatty acid and sterol compositions of the phospholipidglycolipid components were determined by gasliquid chromatography. Differences were found between varieties and between components.
Fatty acids: XXIII. A rapid method for the preparation of C18 furanoid fatty ester involving dry‐column chromatography
Authors: Lie Ken Jie M. S. F. , Chan H. W. M. , Wai J. S. M. , Sinha S.
Published: May 2008

A rapid method for the synthesis of methyl 9,12‐epoxyoctadeca‐9,11‐dienoate from methyl ricinoleate was developed. Methyl ricinoleate was oxidized to the corresponding keto ester, which was treated with mercury (II) acetate to give the required furanoid ester. Dry column silica gel chromatography was used for the purification process and was found to be reliable and efficient.
Effect of salt on the structure and properties of sonicated emulsions stabilized by a tertiary oil recovery formulation
Authors: Vijayan S. , Ramachandran C. , Shah D. O.
Published: May 2008

Structure of sonicated emulsions obtained by varying sodium chloride concentration in surfactant formulations containing 5% (w/w) TRS 10–410 (a petroleum sulfonate), 3% (w/w) isobutanol and equal volumes of aqueous and dodecane oil phases was studied by scanning electron microscopy. The microstructure of these emulsions together with that of the mutually equilibrated oil and aqueous phases was investigated by electron spin resonance (ESR) technique. Extensive physical property data for the emulsion system and for the equilibrated phases were measured. The phase inversion of emulsions from O/W type at low salinities to W/O type at high salinities was confirmed by ESR, viscosity and electrical conductivity measurements. With increasing salt concentration, the macroemulsion passed through a series of structural changes as revealed by the electron microscopy results. A detailed analysis of viscosity and electrical conductivity of the emulsions is presented. The anomalous behavior of the emulsion at optimal salinity is highlighted. A discussion to correlate the structure, stability and type of emulsions with physical property behavior as a function of electrolyte concentration is included.
Quaternization of imidazoline: Unequivocal structure proof
Authors: Trivedi B. C. , Digioia A. J. , Menardi P. J.
Published: May 2008

Two structures are possible for the product of quaternization of an N‐alkylimidazoline, i.e., symmetrical and unsymmetrical. The literature employs both versions, with no unambiguous proof available for either. Proton and13C nuclear magnetic resonance spectroscopy have been used in this work. The product of quaternization under neutral conditions is shown to be symmetrical. This can be easily rationalized on the basis of resonance stabilization caused by delocalization of the positive charge.
Synthesis and properties of amphoteric surfactants
Authors: Gawish S. M. , Hazzaa A. A. B. , Zourab Sh. , El‐Din Gebril B.
Published: May 2008

Carboxylic amphoteric surfactants containing ether tertiary amino and carboxylic groups were prepared. Specifically, 2‐(2‐dimethyl‐aminoethoxy)octadecanoic, hexadecanoic and dodecanoic acid hydrochloride were synthesized. Surface and interfacial tension, emulsifying action, corrosion inhibition effect and after‐treatment of direct dyed cotton fabrics were determined for these surfactants. Antibacterial activities were also examined.
Asymptotic spreading of KPP reactive fronts in incompressible space–time random flows
Authors: Nolen James , Xin Jack
Published: April 2008

We study the asymptotic spreading of Kolmogorov–Petrovsky–Piskunov (KPP) fronts in space–time random incompressible flows in dimensiond > 1. We prove that if the flow field is stationary, ergodic, and obeys a suitable moment condition, the large time front speeds (spreading rates) are deterministic in all directions for compactly supported initial data. The flow field can become unbounded at large times. The front speeds are characterized by the convex rate function governing large deviations of the associated diffusion in the random flow. Our proofs are based on the Harnack inequality, an application of the sub-additive ergodic theorem, and the construction of comparison functions. Using the variational principles for the front speed, we obtain general lower and upper bounds of front speeds in terms of flow statistics. The bounds show that front speed enhancement in incompressible flows can grow at most linearly in the root mean square amplitude of the flows, and may have much slower growth due to rapid temporal decorrelation of the flows.

On étudie le comportement asymptotique des solutions des équations de réaction–diffusion du type Kolmogorov–Petrovsky–Piskunov (KPP) avec convection stochastique en dimensiond > 1. Dans le cas où l'écoulement est stationnaire et ergodique, nous démontrons que la solution forme un front qui se propage avec une vitesse déterministe. Les vitesses de propagation satisfont une formule variationnelle associée à un principe de grandes déviations pour un processus de diffusion en milieu aléatoire. Avec cette formule, nous obtenons quelques estimations de la vitesse. Les preuves sont basées sur une inégalité de type Harnack, le principe de maximum, et le théorème ergodique sous-additif.
On the geometry of null cones in Einstein-vacuum spacetimes
Authors: Wang Qian
Published: April 2008

In this paper we study the geometry of null cones in smooth Einstein vacuum spacetimes. We provide the

L^{\infty }

estimate for the trace of the null second fundamental form, as well as estimates for other geometric quantities. This paper is based on the work of Klainerman and Rodnianski [S. Klainerman, I. Rodnianski, Causal geometry of Einstein-vacuum spacetimes with finite curvature flux, Invent. Math. 159 (3) (2005) 437–529; S. Klainerman, I. Rodnianski, Sharp trace theorems for null hypersurfaces on Einstein metrics with finite curvature flux, Geom. Funct. Anal. 16 (1) (2006) 164–229; S. Klainerman, I. Rodnianski, A geometric Littlewood–Paley theory, Geom. Funct. Anal. 16 (1) (2006) 126–163].
Null controllability of the complex Ginzburg–Landau equation
Authors: Rosier Lionel , Zhang Bing-Yu
Published: April 2008

The paper investigates the boundary controllability, as well as the internal controllability, of the complex Ginzburg–Landau equation. Zero-controllability results are derived from a new Carleman estimate and an analysis based upon the theory of sectorial operators.

Dans ce papier on étudie la contrôlabilité au bord, ainsi que la contrôlabilité interne, de l'équation de Ginzburg–Landau complexe. On obtient des résultats de contrôlabilité à zéro au moyen d'une inégalité de Carleman et d'une analyse basée sur la théorie des opérateurs sectoriels.
On the periodic KdV equation in weighted Sobolev spaces
Authors: Pöschel Jürgen , Kappeler Thomas
Published: April 2008

We prove well-posedness results for the initial value problem of the periodic KdV equation as well as Kam type results in classes of high regularity solutions. More precisely, we consider the problem in weighted Sobolev spaces, which comprise classical Sobolev spaces, Gevrey spaces, and analytic spaces. We show that the initial value problem is well posed in all spaces with subexponential decay of Fourier coefficients, and ‘almost well posed’ in spaces with exponential decay of Fourier coefficients.
Genetic variation in the schizophrenia-risk gene neuregulin1 correlates with personality traits in healthy individuals
Authors: Krug Axel , Markov Valentin , Leube Dirk , Zerres Klaus , Eggermann Thomas , Nöthen Markus M. , Skowronek Markus H. , Rietschel Marcella , Kircher Tilo
Published: May 2008

Background

Differences in personality traits have long been acknowledged as potential risk factors in developing psychiatric disorders. Lately, several susceptibility genes of different psychiatric disorders have been linked to personality traits. This has not been done for schizophrenia yet. Neuregulin1 has been repeatedly shown to be associated with schizophrenia and is involved in numerous neurodevelopmental functions such as neuronal migration and myelination. The impact of this gene might also modulate personality traits in healthy subjects.

Methods

TheNRG1status of 523 healthy subjects was determined with a single nucleotide polymorphism (SNP8NRG221533) which has been described as a tagging marker being part of the core at-risk haplotype for schizophrenia. Genotype was correlated with personality traits using the NEO-FFI questionnaire.

Results

Subjects with theNRG1risk allele scored higher on neuroticism (p<.05) and lower on conscientiousness (p<.05). Further, interactions of genotype by gender for extraversion (p<.05), openness (p<.05) and conscientiousness (p<.05) were found with men carrying the risk allele scoring the lowest.

Conclusions

The data indicate that theNRG1gene which has found to be associated with schizophrenia may also influence personality differences in healthy subjects.
Reduced response to adiponectin and lower abundance of adiponectin receptor proteins in type 2 diabetic monocytes
Authors: Weigert Johanna , Neumeier Markus , Wanninger Josef , Wurm Sylvia , Kopp Andrea , Schober Franziska , Filarsky Michael , Schäffler Andreas , Zeitoun Martina , Aslanidis Charalampos , Buechler Christa
Published: April 2008

The abundance of the adiponectin receptors, AdipoR1 and AdipoR2, and the effects of the antidiabetic adipokine adiponectin in monocytes of normal‐weight and overweight controls and type 2 diabetic patients (T2D) were analyzed. AdipoR1 and AdipoR2 mRNAs were increased in monocytes of obese controls and T2D patients when compared to normal‐weight controls, and AdipoR1 mRNA positively correlated to AdipoR2 mRNA, the waist to hip ratio and systemic adiponectin. However, AdipoR1 and AdipoR2 proteins were lower in monocytes of T2D compared to normal‐weight donors. Induction of IL‐6 and IL‐8 by adiponectin, an effect involving p38 MAPK, was also reduced in T2D monocytes.
On the Rho'd: The regulation of membrane protrusions by Rho‐GTPases
Authors: Ladwein Markus , Rottner Klemens
Published: April 2008

Cell migration entails the formation of cellular protrusions such as lamellipodia or filopodia, the growth of which is powered by the polymerisation of actin filaments abutting the plasma membrane. Specific Rho‐GTPase subfamilies are able to drive different types of protrusions. However, significant crosstalk between Rho‐family members and the interplay of distinct Rho‐effectors regulating or modulating actin reorganization in protrusions complicate the picture of how precisely they are initiated and maintained. Here, we briefly sketch our current knowledge on structure and dynamics of different protrusions as well as their regulation by Rho‐GTPases. We also comment on topical, unresolved controversies in the field, with special emphasis on the interrelation of different protrusion types, and on the composition of the nanomachineries driving them.
A Solanum tuberosum inositol phosphate kinase (StITPK1) displaying inositol phosphate–inositol phosphate and inositol phosphate–ADP phosphotransferase activities
Authors: Caddick Samuel E.K. , Harrison Christopher J. , Stavridou Ioanna , Mitchell Jennifer L. , Hemmings Andrew M. , Brearley Charles A.
Published: April 2008

We describe a multifunctional inositol polyphosphate kinase/phosphotransferase from Solanum tuberosum, StITPKα (GenBank accession number: EF362784), hereafter called StITPK1. StITPK1 displays inositol 3,4,5,6‐tetrakisphosphate 1‐kinase activity: K
m
= 27 μM, and V
max
= 19 nmol min−1
mg−1. The enzyme displays inositol 1,3,4,5,6‐pentakisphosphate 1‐phosphatase activity in the absence of a nucleotide acceptor and inositol 1,3,4,5,6‐pentakisphosphate–ADP phosphotransferase activity in the presence of physiological concentrations of ADP. Additionally, StITPK1 shows inositol phosphate‐inositol phosphate phosphotransferase activity. Homology modelling provides a structural rationale of the catalytic abilities of StITPK1. Inter‐substrate transfer of phosphate groups between inositol phosphates is an evolutionarily conserved function of enzymes of this class.
Fasting heat production and energy cost of standing activity in veal calves
Authors: Labussière Etienne , Dubois Serge , van Milgen Jaap , Bertrand Gérard , Noblet Jean
Published: April 2008

Metabolic body size of veal calves is still calculated by using the 0·75 exponent and no data were available to determine energy cost of physical activity during the whole fattening period. Data from two trials focusing on protein and/or energy requirements were used to determine the coefficient of metabolic body size and the energy cost of standing activity in male Prim'Holstein calves. Total heat production was measured by indirect calorimetry in ninety-five calves weighing 60–265 kg and was divided using a modelling approach between components related to the BMR, physical activity and feed intake. The calculation of the energy cost of standing activity was based on quantifying the physical activity by using force sensors on which the metabolism cage was placed and on the interruption of an IR beam allowing the determination of standing or lying position of the calf. The best exponent relating zero activity fasting heat production (FHP0) to metabolic body size was 0·85, which differed significantly from the traditionally used 0·75. Per additional kJ metabolizable energy (ME) intake, FHP0 increased by 0·28 kJ; at a conventional daily 650 kJ/kg body weight (BW)0·85 ME intake, daily FHP0 averaged 310 kJ/kg BW0·85. Calves stood up sixteen times per day; total duration of standing increased from 5·1 to 6·4 h per day as animals became older. The hourly energy cost of standing activity was proportional to BW0·65 and was estimated as 12·4 kJ/kg BW0·65. These estimates allow for a better estimation of the maintenance energy requirements in veal calves.
The Political Dynamics of Agricultural Liberalisation in the US-Chile Free Trade Agreement
Authors: LEIGHT JESSICA
Published: April 2008

The 2003 US-Chile free trade agreement, regarded by many as consistent with Chile's long-held trade liberalisation strategy, nonetheless engendered a surprisingly vigorous debate focused on the proposed elimination of the bandas de precio protecting traditional agricultural crops. Opposition to the agreement, mounted by the conservative Alianza por Chile, offers an intriguing political case study that suggests that populist posturing surrounding free trade agreements may persist long after a trade liberalisation strategy has become well-established. This article argues that agricultural liberalisation will be a significant challenge for Chile's governing coalition if it wishes to pursue trade negotiations while seeking to avoid costly political battles at home over the economic costs of abandoning price supports and the challenges of ‘reconverting’ to an export-oriented sector. Even given the strong elite consensus around trade liberalisation in Chile, the interconnections between sectoral interest groups, domestic politics and trade negotiations remain relevant, and deserving of analytical attention.
A reply to Robert Larmer
Authors: McDERMID KIRK
Published: May 2008

The metaphysics of miracles put forward in my article, ‘Miracles: metaphysics, physics and physicalism’, above (125–147) are, argues Robert Larmer, both unnecessary and unworkable. Here, I try more clearly to explain that my goal of saving important physicalist intuitions that are incompatible with both the ‘open-systems’ and ‘exemption’ approaches’ use of powerfulceteris paribusclauses. I also defend the two mechanisms proposed in the paper from Larmer's criticisms.
Cones arising from C*-subalgebras and complete positivity
Authors: POP FLORIN , SMITH ROGER R.
Published: April 2008

Let B ⊆ A be an inclusion of C*-algebras. Then B is said to norm A if, for each X ∈ ${\bb M}_n$(A),

In this paper we introduce and study the cones

These are shown to coincide with the standard positive cones precisely when B norms A, and we apply this to obtain automatic complete positivity of certain positive maps between C*-algebras.
Linear algebra algorithms as dynamical systems
Authors: Chu Moody T.
Published: April 2008

Any logical procedure that is used to reason or to infer either deductively or inductively, so as to draw conclusions or make decisions, can be called, in a broad sense, a realization process. A realization process usually assumes the recursive form that one state develops into another state by following a certain specific rule. Such an action is generally formalized as a dynamical system. In mathematics, especially for existence questions, a realization process often appears in the form of an iterative procedure or a differential equation. For years researchers have taken great effort to describe, analyse, and modify realization processes for various applications.

The thrust in this exposition is to exploit the notion of dynamical systems as a special realization process for problems arising from the field of linear algebra. Several differential equations whose solutions evolve in submanifolds of matrices are cast in fairly general frameworks, of which special cases have been found to afford unified and fundamental insights into the structure and behaviour of existing discrete methods and, now and then, suggest new and improved numerical methods. In some cases, there are remarkable connections between smooth flows and discrete numerical algorithms. In other cases, the flow approach seems advantageous in tackling very difficult open problems. Various aspects of the recent development and application in this direction are discussed in this paper.
Coolwater culmination: Sensitive high‐resolution ion microprobe (SHRIMP) U‐Pb and isotopic evidence for continental delamination in the Syringa Embayment, Salmon River suture, Idaho
Authors: Lund Karen , Aleinikoff J. N. , Yacob E. Y. , Unruh D. M. , Fanning C. M.
Published: April 2008

During dextral oblique translation along Laurentia in western Idaho, the Blue Mountains superterrane underwent clockwise rotation and impinged into the Syringa embayment at the northern end of the Salmon River suture. Along the suture, the superterrane is juxtaposed directly against western Laurentia, making this central Cordilleran accretionary‐margin segment unusually attenuated. In the embayment, limited orthogonal contraction produced a crustal wedge of oceanic rocks that delaminated Laurentian crust. The wedge is exposed through Laurentian crust in the Coolwater culmination as documented by mapping and by sensitive high‐resolution ion microprobe U‐Pb, Sri, and ɛNd data for gneisses that lie inboard of the suture. The predominant country rock is Mesoproterozoic paragneiss overlying Laurentian basement. An overlying Neoproterozoic (or younger) paragneiss belt in the Syringa embayment establishes the form of the Cordilleran miogeocline and that the embayment is a relict of Rodinia rifting. An underlying Cretaceous paragneiss was derived from arc terranes and suture‐zone orogenic welt but also from Laurentia. The Cretaceous paragneiss and an 86‐Ma orthogneiss that intruded it formed the wedge of oceanic rocks that were inserted into the Laurentian margin between 98 and 73 Ma, splitting supracrustal Laurentian rocks from their basement. Crustal thickening, melting and intrusion within the wedge, and folding to form the Coolwater culmination continued until 61 Ma. The embayment formed a restraining bend at the end of the dextral transpressional suture. Clockwise rotation of the impinging superterrane and overthrusting of Laurentia that produced the crustal wedge in the Coolwater culmination are predicted by oblique collision into the Syringa embayment.
Modulated reconnection rate and energy conversion at the magnetopause under steady IMF conditions
Authors: Rosenqvist L. , Vaivads A. , Retinò A. , Phan T. , Opgenoorth H. J. , Dandouras I. , Buchert S.
Published: April 2008

We use the multi‐spacecraft mission Cluster to make observational estimates of the local energy conversion across the dayside high‐latitude magnetopause. The energy conversion is estimated during eleven complete magnetopause crossings under steady south‐dawnward interplanetary magnetic field (IMF). We describe a new method to determine the reconnection rate from the magnitude of the local energy conversion. The reconnection rate as well as the energy conversion varies during the course of the eleven crossings and is typically much higher for the outbound crossings. This supports the previous interpretation that reconnection is continuous but its rate is modulated.
Characterizing the tropospheric ozone response to methane emission controls and the benefits to climate and air quality
Authors: Fiore Arlene M. , West J. Jason , Horowitz Larry W. , Naik Vaishali , Schwarzkopf M. Daniel
Published: April 2008

Reducing methane (CH4) emissions is an attractive option for jointly addressing climate and ozone (O3) air quality goals. With multidecadal full‐chemistry transient simulations in the MOZART‐2 tropospheric chemistry model, we show that tropospheric O3 responds approximately linearly to changes in CH4 emissions over a range of anthropogenic emissions from 0–430 Tg CH4 a−1 (0.11–0.16 Tg tropospheric O3 or ∼11–15 ppt global mean surface O3 decrease per Tg a−1 CH4 reduced). We find that neither the air quality nor climate benefits depend strongly on the location of the CH4 emission reductions, implying that the lowest cost emission controls can be targeted. With a series of future (2005–2030) transient simulations, we demonstrate that cost‐effective CH4 controls would offset the positive climate forcing from CH4 and O3 that would otherwise occur (from increases in NOx and CH4 emissions in the baseline scenario) and improve O3 air quality. We estimate that anthropogenic CH4 contributes 0.7 Wm−2 to climate forcing and ∼4 ppb to surface O3 in 2030 under the baseline scenario. Although the response of surface O3 to CH4 is relatively uniform spatially compared to that from other O3 precursors, it is strongest in regions where surface air mixes frequently with the free troposphere and where the local O3 formation regime is NOx‐saturated. In the model, CH4 oxidation within the boundary layer (below ∼2.5 km) contributes more to surface O3 than CH4 oxidation in the free troposphere. In NOx‐saturated regions, the surface O3 sensitivity to CH4 can be twice that of the global mean, with >70% of this sensitivity resulting from boundary layer oxidation of CH4. Accurately representing the NOx distribution is thus crucial for quantifying the O3 sensitivity to CH4.
Enhancing the estimation of continental‐scale snow water equivalent by assimilating MODIS snow cover with the ensemble Kalman filter
Authors: Su Hua , Yang Zong‐Liang , Niu Guo‐Yue , Dickinson Robert E.
Published: April 2008

High‐quality continental‐scale snow water equivalent (SWE) data sets are generally not available, although they are important for climate research and water resources management. This study investigates the feasibility of a framework for developing such needed data sets over North America, through the ensemble Kalman filter (EnKF) approach, which assimilates the snow cover fraction observed by the Moderate Resolution Imaging Spectroradiometer (MODIS) into the Community Land Model (CLM). We use meteorological forcing from the Global Land Data Assimilation System (GLDAS) to drive the CLM and apply a snow density‐based observation operator. This new operator is able to fit the observed seasonally varying relationship between the snow cover fraction and the snow depth. Surface measurements from Canada and the Advanced Microwave Scanning Radiometer‐Earth Observing System (AMSR‐E) estimates (in particular regions) are used to evaluate the assimilation results. The filter performance, including its ensemble statistics in different landscapes and climatic zones, is interpreted. Compared to the open loop, the EnKF method more accurately simulates the seasonal variability of SWE and reduces the uncertainties in the ensemble spread. Different simulations are also compared with spatially distributed climatological statistics from a re‐gridded data set, which shows that the SWE estimates from the EnKF are most improved in the mountainous west, the northern Great Plains, and the west and east coast regions. Limitations of the assimilation system are analyzed, and the domain‐wide innovation mean and normalized innovation variance are assessed, yielding valuable insights (e.g., about the misrepresentation of filter parameters) as to implementing the EnKF method for large‐scale snow properties estimation.
Development of kinetic-based energy exchange models for noncontinuum, ionized hypersonic flows
Authors: Ozawa T. , Zhong Jiaqiang , Levin D. A.
Published: April 2008

Ultrahigh Mach number re-entry vehicles create sufficiently energetic flow conditions with substantial ionization occurring in the noncontinuum flow regime. To model these noncontinuum, ionized, and thermochemically nonequilibrium flows, a direct simulation Monte Carlo (DSMC) approach is investigated. Energy exchange models that have been developed for Navier–Stokes computational fluid dynamics computations are examined and revised for application to the DSMC method. Since the electron–heavy particle collision rate is approximately two orders of magnitude higher than that between heavy particles, a new model is developed for electron scattering collision processes and electron-vibrational energy exchange based on the electron-molecule shape resonance phenomena. It is found that the flow electron and vibrational temperatures are sensitive to the electron-vibrational relaxation model because the relaxation time changes by orders of magnitude. The DSMC calculations of the bow-shock region of a blunt body were found to predict the correct flow features for free stream Knudsen numbers spanning the near-free molecular to the continuum limit. The range of degree of ionization was found to vary from the highest altitude to the lowest from 1% to 11%.
Beat excitation of whistlers in the presence of field aligned irregularities in the ionosphere
Authors: Sodha M. S. , Bhasin Lalita , Tripathi V. K.
Published: April 2008

In equatorial ionospheric plasma, embedded with a density ripple, a low frequency whistler can be resonantly excited by the nonlinear mixing of two high frequency radio waves launched from the ground at an oblique angle. A suitable configuration is where the earth magnetic field is along ẑ (horizontal), ripple wave number q⃗‖ŷ (horizontal), and high frequency wave numbers are k⃗1=k1cosθẑ+k1sinθ(cosϕx̂+sinϕŷ), k⃗2=−k2cosθẑ+k2sinθ(cosϕx̂−sinϕŷ). Phase matching conditions are satisfied for large θ and small ϕ. The radio waves exert a ponderomotive force on electrons at the beat frequency imparting them an oscillatory velocity with a component perpendicular to the magnetic field. This velocity, in conjunction with the density ripple, produces a current that drives the whistler. The Ohmic nonlinearity is found to be relatively weaker in comparison to ponderomotive nonlinearity at higher heights. However in the E-region, this nonlinearity reinforces with the ponderomotive nonlinearity and can improve the whistler power generation.
The toroidal momentum diffusivity in a tokamak plasma: A comparison of fluid and kinetic calculations
Authors: Strintzi D. , Peeters A. G. , Weiland J.
Published: April 2008

Fluid and gyrokinetic calculations of the toroidal momentum diffusivity in a tokamak are compared. The four-moment gyrofluid model predicts the Prandtl number connected with the ion temperature gradient mode reasonably well provided the drift term is kept in the momentum balance. Without the drift term in the momentum balance, some previous gyrofluid models predicted small values of the Prandtl number in the range of experimental observations. It is shown that the drift term enters in the fluid equations through the gyroviscosity. Gyrokinetic calculations of the ion temperature gradient mode with kinetic electrons, and for experimentally relevant parameters yield a Prandtl number in the range 0.7–1.2.
Ultrafast nonradiative dynamics in electronically excited hexafluorobenzene by femtosecond time-resolved mass spectrometry
Authors: Studzinski Harald , Zhang Song , Wang Yanmei , Temps Friedrich
Published: April 2008

The fast nonradiative decay dynamics of the lowest two excited ππ* electronic states (S2 and S3) of hexafluorobenzene have been investigated by using femtosecond time-resolved time-of-flight mass spectrometry. The molecules were excited at wavelengths between 265nm⩾λpump⩾217nm and probed by four- and three-photon ionization at λprobe=775nm. The observed temporal profiles exhibit two exponential decay times (τ1=0.54–0.1ps and τ2=493–4.67ps, depending on the excitation wavelength) and a superimposed coherent oscillation with vibrational frequency νosc=97cm−1 and damping time τD that is two to three times longer than the respective τ1. The first decay component (τ1) is assigned to rapid radiationless transfer from the excited optically bright ππ* electronic state (S2 or S3, respectively) through a conical intersection (CI) to the lower-lying optically dark πσ* state (S1) of the molecule; the second component (τ2) is attributed to the subsequent slower relaxation from the S1 state back to the electronic ground state (S0). τ2 dramatically decreases with increasing vibronic excitation energy up to the CI connecting the πσ* with the S0 state. The coherent oscillation is identified as nuclear motion along the out-of-plane vibration ν16a (notation as for benzene), which has e2u symmetry and acts as coupling mode between the ππ* and πσ* states.
Position dependent spatial and spectral resolution measurement of distributed readout superconducting imaging detectors
Authors: Hijmering R. A. , Verhoeve P. , Kozorezov A. G. , Martin D. D. E. , Wigmore J. K. , Jerjen I. , Venn R. , Groot P. J.
Published: April 2008

We present direct measurements of spatial and spectral resolution of cryogenic distributed readout imaging detectors (DROIDs). The spatial and spectral resolutions have been experimentally determined by scanning a 10μm spot of monochromatic visible light across the detector. The influences of the photon energy, bias voltage, and absorber length and width on the spatial and spectral resolutions have been examined. The confinement of quasiparticles in the readout sensors (superconducting tunnel junctions) as well as the detector’s signal amplitude can be optimized by tuning the bias voltage, thereby improving both the spatial and spectral resolutions. Changing the length of the absorber affects the spatial and spectral resolutions in opposite manner, making it an important parameter to optimize the DROID for the application at hand. The results have been used to test expressions for photon energy, position, and spatial and spectral resolutions which have been derived by using an existing one-dimensional model. The model is found to accurately describe the experimental data, but some limitations have been identified. In particular, the model’s assumption that the two sensors have identical response characteristics and noise, the approximation of the detailed quasiparticle dynamics in the sensors by border conditions, and the use of a one-dimensional diffusion process is not always adequate.
Magnetocapacitance of polycrystalline Bi5Ti3FeO15 prepared by sol-gel method
Authors: Dong X. W. , Wang K. F. , Wan J. G. , Zhu J. S. , Liu J.-M.
Published: May 2008

Bi 5 Ti 3 Fe O 15 bulk ceramic and thin film samples are prepared using the sol-gel method. The dielectric, ferroelectric, and magnetic behaviors of these samples are measured in order to investigate the possible multiferroic effect. The superparamagnetic behavior with dominant antiferromagnetic (AFM) interaction background for the as-prepared Bi5Ti3FeO15 samples is revealed. The clearly identified magnetocapacitance effect at low temperature is argued to originate from the suppression of the AFM interaction by external magnetic field.
Coarse-grained molecular dynamics simulation on the placement of nanoparticles within symmetric diblock copolymers under shear flow
Authors: Kalra Vibha , Mendez Sergio , Escobedo Fernando , Joo Yong Lak
Published: April 2008

We present molecular dynamics simulations coupled with a dissipative particle dynamics thermostat to model and simulate the behavior of symmetric diblock copolymer/nanoparticle systems under simple shear flow. We consider two categories of nanoparticles, one with selective interactions toward one of the blocks of a model diblock copolymer and the other with nonselective interactions with both blocks. For the selective nanoparticles, we consider additional variants by changing the particle diameter and the particle-polymer interaction potential. The aim of our present study is to understand how the nanoparticles disperse in a block copolymer system under shear flow and how the presence of nanoparticles affects the rheology, structure, and flow behavior of block copolymer systems. We keep the volume fraction of nanoparticles low (0.1) to preserve lamellar morphology in the nanocomposite. Our results show that shear can have a pronounced effect on the location of nanoparticles in block copolymers and can therefore be used as another parameter to control nanocomposite self-assembly. In addition, we investigate the effect of nanoparticles on shear-induced lamellar transition from parallel to perpendicular orientation to further elucidate nanocomposite behavior under shear, which is an important tool to induce long-range order in self-assembling materials such as block copolymers.