bluuebunny/crossref_metadata_2025 huggingface dataset:
Self-consistent fluid variational theory for the dissociation of dense nitrogen
Authors: Chen Qi-Feng , Cai Ling-Cang , Zhang Ying , Gu Yong-Jun , Jing Fu-Qian
Published: February 2006

The self-consistent fluid variational theory is used to calculate the pressure dissociation of dense nitrogen at high temperatures. The accurate high-pressure and high-temperature effective pair potentials are adopted to describe the intermolecular interactions, which are made to consider molecular dissociation. This paper focuses on a mixture of nitrogen atoms and molecules and is devoted to the study of the phenomenon of pressure dissociation at finite temperature. The equation of state and dissociation degree are calculated from the free-energy functions in the range of temperature of 2000–15000K and density of 0.2–3.0g∕cm3, which can be compared with other approaches and experiments.
Evidence of CH2O(ãA23) and C2H4(ãB1u3) produced from photodissociation of 1,3-trimethylene oxide at 193nm
Authors: Lee Shih-Huang , Ong Chee-Siong , Lee Yuan T.
Published: February 2006

We investigated the dissociative ionization of formaldehyde (CH2O) and ethene (C2H4) produced from photolysis of 1,3-trimethylene oxide at 193nm using a molecular-beam apparatus and vacuum-ultraviolet radiation from an undulator for direct ionization. The CH2O (C2H4) product suffers from severe dissociative ionization to HCO+ (C2H3+ and C2H2+) even though photoionization energy is as small as 9.8eV. Branching ratios of fragmentation of CH2O and C2H4 following ionization are revealed as a function of kinetic energy of products using ionizing photons from 9.8to14.8eV. Except several exceptions, branching ratios of daughter ions increase with increasing photon energy but decrease with increasing kinetic energy. The title reaction produces CH2O and C2H4 mostly on electronic ground states but a few likely on triplet states; C2H4(ãB1u3) seems to have a yield greater than CH2O(ãA23). The distinct features observed at small kinetic energies of daughter ions are attributed to dissociative ionization of photoproducts CH2O(ãA23) and C2H4(ãB1u3). The observation of triplet products indicates that intersystem crossing occurs prior to fragmentation of 1,3-trimethylene oxide.
Calculation of the charge-carrier mobility of polyguanylic acid: The simultaneous effect of stretching and twisting
Authors: Beleznay F. B. , Bogar F. , Szekeres Zs. , Ladik J.
Published: February 2006

Charge-carrier (electron and hole) mobilities of polyguanylic acid have been computed using the deformation-potential approximation from ab initio Hartree-Fock band structure. Mobilities resulting from electron scattering on torsional acoustic phonons are calculated and compared to those obtained from a previous calculation [F. B. Beleznay et al., J. Chem. Phys. 119, 5690 (2003)] considering interaction with compressional phonons. The simultaneous effect of the two independent scatterings is also calculated.
Theoretical rate coefficients for the exchange reaction OH+D→OD+H
Authors: Wang Wenli , Santos Emanuel , Brandão João
Published: February 2006

In this work quasiclassical trajectory calculations were carried out to determine directly the rate coefficients for the isotopic exchange reaction, OH+D→OD+H, using a potential-energy surface that carefully accounts for the long-range interactions. The calculated thermal rate coefficients are in good agreement with the experimental results.
Theory of “laser distillation” of enantiomers: Purification of a racemic mixture of randomly oriented dimethylallene in a collisional environment
Authors: Gerbasi David , Shapiro Moshe , Brumer Paul
Published: February 2006

Enantiomeric control of 1,3 dimethylallene in a collisional environment is examined. Specifically, our previous “laser distillation” scenario wherein three perpendicular linearly polarized light fields are applied to excite a set of vib-rotational eigenstates of a randomly oriented sample is considered. The addition of internal conversion, dissociation, decoherence, and collisional relaxation mimics experimental conditions and molecular decay processes. Of greatest relevance is internal conversion which, in the case of dimethylallene, is followed by molecular dissociation. For various rates of internal conversion, enantiomeric control is maintained in this scenario by a delicate balance between collisional relaxation of excited dimethylallene that enhances control and collisional dephasing, which diminishes control.
Hot bands in jet-cooled and ambient temperature spectra of chloromethylene
Authors: Wang Zhong , Bird Ryan G. , Yu Hua-Gen , Sears Trevor J.
Published: February 2006

Rotationally resolved spectra of several bands lying to the red of the origin of the ÃA″1−X̃A′1 band system of chloromethylene (HCCl), were recorded by laser absorption spectroscopy in ambient temperature and jet-cooled samples. The radical was made by excimer laser photolysis of dibromochloromethane, diluted in inert gas, at 193nm. The jet-cooled sample showed efficient rotational but less vibrational cooling. Analysis showed that the observed bands originate in the (υ1,υ2,υ3)=(010), (001), and (011) vibrational levels of the ground electronic state of the radical, while the upper-state levels involved were (000), (010), (001), and (011). Vibrational energies and rotational constants describing the rotational levels in the lower-state vibrational levels were determined by fitting to combination differences. The analysis also resulted in a reevaluation of the C–Cl stretching frequency in the excited state and we find E001′=13206.57 or 926.17cm−1 above the ÃA″1(000) rotationless level for HC35Cl. Scaled ab initio potential energy surfaces for the Ã and X̃ states were used to compute the transition moment surface and thereby the relative intensities of different vibronic transitions, providing additional support for the assignments and permitting the prediction of the shorter wavelength spectrum. All the observed upper state levels showed some degree of perturbation in their rotational energy levels, particularly in Ka=1, presumably due to coupling with near-resonant vibrationally excited levels of the ground electronic state. Transitions originating in the low-lying ãA″3 were also predicted to occur in the same wavelength region, but could not be identified in the spectra.
Dynamics of the O(P3)+H2 reaction at low temperatures: Comparison of quasiclassical trajectory with quantum scattering calculations
Authors: Weck P. F. , Balakrishnan N. , Brandão J. , Rosa C. , Wang W.
Published: February 2006

Quasiclassical trajectory and quantum-mechanical scattering calculations are reported for the O(P3)+H2(XΣg+1;υ=1−3,j=0)→OH(XΠ2)+H(S2) reaction at energies close to the reaction threshold. The dynamics of the reaction have been investigated for zero total angular momentum using the lowest A″3 potential-energy surface developed by Rogers et al. [J. Phys. Chem. A 104, 2308 (2000)] and its recent extensions by Brandão et al. [J. Chem. Phys. 121, 8861 (2004)] which provide an improved description of the van der Waals interaction. Good agreement is observed for this system between quasiclassical and quantal results for incident kinetic energies above the tunneling regime. Quantum-mechanical calculations also confirm recent theoretical predictions of a strong collision-energy dependence of the OH(v′=0)∕OH(v′=1) product branching ratio in the O(P3)+H2(v=1) reaction, which explains the differences observed in OH vibrational populations between experiments using different O(P3) sources.
Nanoimprinting-lithography-induced self-aligned liquid crystals for novel multifunctional optical films
Authors: Chiu Chih-Ho , Kuo Hui-Lung , Chen Pin-Cheng , Wen Chun-Hsiang , Liu Yi-Chun , Chen Huang-Ming Philip
Published: February 2006

Polymerizable nematic liquid crystal (LC) was adopted as a resist for our newly developed nanoimprinting lithography process. Liquid crystal molecules were self-aligned during imprinting process without precoated alignment layer. The large patterned area was able to achieve 4×4cm2 at very low impriting pressure, 1.5bar. The optical anisotropic was verified through polarized optical microscopy and the retardation was measured by polarized ultraviolet/visible spectrometer. The micrograted LC films prepared by this novel method offer the potential applications for a LC alignment layer within LC cells, as well as preparation of optical anisotropic films.
Molecular-optic modulator
Authors: Ihara Kazuki , Eshima Chihiro , Zaitsu Shin-Ichi , Kamitomo Singo , Shinzen Kenji , Hirakawa Yasuyuki , Imasaka Totaro
Published: February 2006

An ultrafast light-intensity modulator, based on stimulated Raman scattering, is described. The intensity of a continuous wave laser is fully modulated at 17THz using hydrogen in a high-finesse cavity. The modulation frequency is determined by the molecular constant of the Raman medium, i.e., the Raman shift frequency. The modulation frequency can be changed in the tetrahertz range by replacing the Raman medium. Due to the accurate modulation frequency and the high beam coherence, this device is amenable to a variety of applications such as in basic science and also in advanced industrial technology.
Transparent Ho3+-doped nano-glass-ceramics for efficient infrared emission
Authors: Driesen K. , Tikhomirov V. K. , Görller-Walrand C. , Rodriguez V. D. , Seddon A. B.
Published: February 2006

We developed transparent 3.5mol% Ho3+-doped oxyfluoride nano-glass-ceramics, where the Ho3+-dopants dissolve in the 6nm diameter β-PbF2 nanocrystals. The cubic site of Ho3+ and a low vibration frequency of its PbF2 environment result in an intense and 50nm broad emission band I65→I85 of Ho3+ at 1.2μm with a temperature independent lifetime of 1.6ms. Another 40nm broad emission band F55→I65 at 1.47μm with a lifetime of 24μs was also excited, the lifetime of this band increased to 60μs at 77K. These two bands have potential application for optical amplification in telecommunications.
Initial growth of nanocrystalline diamond/β-SiC composite films: A competitive deposition process
Authors: Srikanth Vadali. V. S. S. , Tan M. H. , Jiang X.
Published: February 2006

Although nanocrystalline diamond/β-SiC composite gradient interlayers have been successfully deposited in dealing with the problem of diamond thin-film adhesion to metallic substrates, initial growth process of the two components has not been described, so far. In this letter, we propose that the deposition of composite interlayer is possible because of a selective growth process of diamond and β-SiC phases. There is a competition between the diamond and the β-SiC crystallites to occupy the spaces available on the substrate. The space competition is during the initial nucleation period of the process and also during film growth, leading to the formation of the nanocrystalline composite. The secondary nucleation of β-SiC on the existing diamond surfaces depends on the flux of incoming β-SiC forming gas species. This provides us with a possibility to control phase structure and composition of the composite film by adjusting the tetramethyl silane flow rate.
Cytoprotective gene
bi-1
is required for intrinsic protection from endoplasmic reticulum stress and ischemia-reperfusion injury
Authors: Bailly-Maitre Béatrice , Fondevila Constantino , Kaldas Fady , Droin Nathalie , Luciano Fréderic , Ricci Jean-Ehrland , Croxton Rhonda , Krajewska Maryla , Zapata Juan M. , Kupiec-Weglinski Jerzy W. , Farmer Douglas , Reed John C.
Published: February 2006

Ischemia-reperfusion (IR) injury induces endoplasmic reticulum (ER) stress and cell death. Bax Inhibitor-1 (BI-1) is an evolutionarily conserved ER protein that suppresses cell death and that is abundantly expressed in both liver and kidney. We explored the role of BI-1 in protection from ER stress and IR injury by using
bi
-
1
knockout mice, employing models of transient hepatic or renal artery occlusion. Compared to wild-type
bi-1
mice,
bi
-
1
knockout mice subjected to hepatic IR injury exhibited these characteristics: (
i
) increased histological injury; (
ii
) increased serum transaminases, indicative of more hepatocyte death; (
iii
) increased percentages of TUNEL-positive hepatocytes; (
iv
) greater elevations in caspase activity; and (
v
) more activation of ER stress proteins inositol-requiring enzyme 1 and activating transcription factor 6 and greater increases in expression of ER stress proteins C/EBP homologous protein and spliced XBP-1 protein. Moreover, hepatic IR injury induced elevations in
bi
-
1
mRNA in wild-type liver, suggesting a need for
bi
-
1
gene induction to limit tissue injury. Similar sensitization of kidney to ER stress and IR injury was observed in
bi
-
1
−/−
mice. We conclude that
bi
-
1
provides endogenous protection of liver and kidney from ER stress and IR injury. Analysis of components of the
bi
-
1
-dependent pathway for protection from IR injury may therefore reveal new strategies for organ preservation.
On the origin and highly likely completeness of single-domain protein structures
Authors: Zhang Yang , Hubner Isaac A. , Arakaki Adrian K. , Shakhnovich Eugene , Skolnick Jeffrey
Published: February 2006

The size and origin of the protein fold universe is of fundamental and practical importance. Analyzing randomly generated, compact sticky homopolypeptide conformations constructed in generic simplified and all-atom protein models, all have similar folds in the library of solved structures, the Protein Data Bank, and conversely, all compact, single-domain protein structures in the Protein Data Bank have structural analogues in the compact model set. Thus, both sets are highly likely complete, with the protein fold universe arising from compact conformations of hydrogen-bonded, secondary structures. Because side chains are represented by their C
β
atoms, these results also suggest that the observed protein folds are insensitive to the details of side-chain packing. Sequence specificity enters both in fine-tuning the structure and thermodynamically stabilizing a given fold with respect to the set of alternatives. Scanning the models against a three-dimensional active-site library, close geometric matches are frequently found. Thus, the presence of active-site-like geometries also seems to be a consequence of the packing of compact, secondary structural elements. These results have significant implications for the evolution of protein structure and function.
Water consumption by rusa deer (Cervus timorensis) stags as influenced by different types of food
Authors: Kii W. Yape , Dryden G. McL.
Published: February 2006

During winter in southern Queensland, eight rusa deer stags aged 4 years were given ad libitum lucerne (Medicago sativa) hay and confined in individual metabolism pens for 26 days. Stags ate 2·04 kg dry matter (DM) per day and drank 6·4 kg water per day, while the drinking water: food DM ratio was 3·3 l/kg. In experiment 2, seven rusa stags were given ad libitum lucerne hay or oaten (Avenaspp.) hay with or without barley grain supplementation (200 g/day) for 56 days (four periods). This experiment was conducted from 26 July to 19 September 2001, when the stags were exhibiting the behaviour characteristic of the rut. Rusa stags ate 1·19 and 1·17 kg DM per day of lucerne and oaten hay respectively. Rusa stags given oaten hay drank slightly more water than those that received lucerne hay (5·34 and 4·47 kg/day, respectively). The drinking water: food DM ratios were 3·81 and 4·67 kg/kg for lucerne and oaten hay, respectively. Barley grain supplementation (200 g/day) had no influence on total food or water intakes of the rusa stags.
Incorporating turn-over in whole body protein retention ef.ciency in pigs
Authors: Roux Z.
Published: February 2006

The magnitude of the discrepancy between conventional regression estimates of protein retention efficiency and theoretical estimates of synthesis efficiency indicates a major contribution ascribable to protein turn-over in the generally accepted estimates. As protein turn-over is known to be influenced by diet, feeding level and degree of maturity, this suggests the development of an estimator of protein efficiency that can be adapted for such differences. Therefore, based on generally accepted formulas for growth description, a method of estimating protein retention efficiency was developed which is flexible enough to accommodate different diets, feeding levels and degrees of maturity. Moreover, a formula was derived to convert one type of estimate to the other by regarding constant efficiency as equivalent to variable efficiency at the mid point of the estimation interval. Increase in scientific depth to this descriptive approach is provided by a theoretical consideration of a possible mechanism of hormonal control of protein synthesis and breakdown, ultimately expressed as proportionalities to powers of whole body protein (P). Molecular considerations on cellular synthesis and breakdown indicate a difference between breakdown and synthesis powers equal to (2/9)Q. The factor (2/9) is indicated by an argument based on insulinlike growth factor derived activator diffusion attributes by nucleus and body tissue geometries, whileQis equal to the proportion of nuclei activated by insulin-like growth factor. This proportion is likely to be a function of the concentration of growth factor in the blood. Hence, a linear relationship between intake and blood insulin-like growth factor concentration suggests thatQcan be represented by a scaled transformation of intake, 0 ≤Q≤ 1, such that a value ofQ= 1 represents ad libitum intake on a suitable diet andQ= 0 intake at the maintenance requirement. The quantification of breakdown and synthesis power differences by (2/9)Qleads to kP= {1 + [1 − (P/α)(2/9)Q]−1/6}−1, for turn-over related protein retention efficiency (kP), with α the limit value of P at maturity, so that 0 ≤ (P/α) ≤ 1. Experimental estimates, derived from direct estimates of whole body protein synthesis and breakdown at predetermined levels of intake, are in excellent agreement with the theoretical (2/9)Qin the power associated with (P/α) in kP. Furthermore, conventional multiple regression retention efficiencies satisfactorily approximate the turn-over related retention efficiency that can be calculated at a given level of intake for the mid point of the interval covered by the regression estimates.
Effect of selection for litter size and feeding programme on the performance of young rabbit females during rearing and first pregnancy
Authors: Quevedo F. , Cervera C. , Blas E. , Baselga M. , Costa C. , Pascual J. J.
Published: February 2006

A total of 166 crossbred young female rabbits were used to study the effect of two types of crossbred does (H1 v. H2, old and current generations, respectively) from the cross of different generations of maternal lines selected for litter size, the use of a feeding programme based on a low energy rearing diet (F) and the presentation of a high-energy dietpre-partum(E) on the performance of young rabbit females until their first parturition and on the main litter traits at first kindling. Perirenal fat was thicker at the age of 3 months for H2 than for H1 does, but this difference disappeared at the first insemination (4·5 months). H2 does had a significantly larger total number and number of live pups at birth (+2·06 live pups) than H1, higher than expected (+1·06). As this greater foetal growth was obtained for a similar energy intake of does, possible differences may exist in partitioning and/or effficiencies of dietary and body energies in favour of foetal growth as the genetic propensity for litter size increased. The use of a low-energy diet significantly reduced the growth of does during the rearing period (−294 g), but they showed a greater compensatory growth during the first 4 weeks of gestation (+79 g) as a consequence of their higher energy intake, without any retardation in their reproductive development. Does receiving diet F until 28th day of gestation showed a significantly greaterpre-partumenergy intake and their number of pups born alive was lower (−1·3 pups). Finally, the litters of females receiving diet Epre-partumand during lactation had lower mortality during the 1st week (26·9 v. 42·9% dead pups) and throughout lactation than those receiving a moderate energy diet.
The effect of digestible undergradable protein (DUP) content of concentrates on colostrum production and lamb performance of triplet-bearing ewes on grass-based diets during late pregnancy
Authors: Annett R. W. , Carson A. F. , Dawson L. E. R.
Published: February 2006

An experiment was carried out to investigate the effects of increasing the digestible undegradable protein (DUP) concentration of concentrates on colostrum production and lamb output from prolific ewe breed types. Sixty triplet-bearing ewes with a mean condition score of 3.75 were allocated to one of five treatments (no. =; 12) for the final 6 weeks of pregnancy. Four of the treatments were offered a restricted grass diet (0.6 kg dry matter (DM) per day) plus one of four isoenergetic and isonitrogenous concentrates (0.56 kg DM per day) that were formulated to provide 25 (P25); 40 (P40); 75 (P75) and 95 (P95) g DUP/kg DM. Control ewes were offered a grass-only diet with the aim of achieving an equivalent total DM intake (1.16 kg DM per day). Concentrate composition had no effect on total diet DM, crude protein or metabolizable energy intakes, but the intake of DUP increased with increasing concentrate DUP level (P< 0.001). Supplementing grass with concentrates led to significant reductions in plasma β-hydroxybutyrate (P< 0.05) and non-esterified fatty acids(P< 0.001) concentrations. Plasma urea concentration tended to be negatively and linearly related to the concentrate DUP level (P< 0.1). Colostrum production and composition were not affected by concentrate type, except for the concentration of gross energy which was highest for P40 ewes. Concentrate feeding led to significant (P< 0.05) increases in colostrum yield 18 h post lambing and colostral outputs of ash, crude protein, total solids and gross energy but resulted in a lower (P< 0.05) colostral immunoglobulin G concentration. Lamb birth weight and total litter weight were not affected by late pregnancy feeding regime. However lamb survival to weaning was reduced significantly (P< 0.05) for P25 and control ewes, resulting in lower levels of lamb output at weaning. The results from this study indicate that offering rumen undegradable rather than rumen degradable protein has no effect on colostrum production and lamb performance when ewes are offered high quality grass-based diets in late pregnancy.
Use of carcass weight to classify Manchego sucking lambs and its relation to carcass and meat quality
Authors: Díaz M. T. , de la Fuente J. , Lauzurica S. , Pérez C. , Velasco S. , Álvarez I. , de Huidobro F. Ruiz , Onega E. , Blázquez B. , Cañeque V.
Published: February 2006

Eighty-seven Manchego sucking lambs raised exclusively on maternal milk were slaughtered. The carcasses were weighed immediately after dressing and classified according to hot carcass weight (HCW): low HCW (<5.5 kg), medium HCW (5.5 to 6.5 kg) and high HCW (≥ 6.5 kg). The effects of this classification system on carcass and meat quality were studied. Carcass conformation improved as carcass weight increased; carcasses became more compact. Carcass fatness increased (P< 0.001) as carcasses became heavier. With regard to the joints, leg (P< 0.001) and shoulder (P< 0.05) proportions decreased as carcass weight increased, whereas loin-rib (P< 0.001) and flank (P< 0.001) proportions increased. The proportion of fat in the leg clearly increased in the heavier carcasses (P< 0.001), while that of bone decreased (P< 0.001) and that of muscle was not affected. pH at 24 h in them. longissimusdorsi andm. semitendinosusdecreased as carcass weight increased. The only meat colour parameter affected by carcass weight was the yellowness index; lighter-weight carcasses displayed lower index (P< 0.05). Cooking losses were unaffected as carcass weight increased, whereas with regard to tenderness, the shear force value tended to be higher in the low carcass weight group. No differences between carcass weight groups were found in the sensory analysis. Fatty acid composition did not show any significant effect due to carcass weight except in stearic fatty acid (C18:0); C18:0 proportion decreased (P< 0.01) as carcasses became heavier. Carcass weight affected carcass quality (all carcass quality parameters studied were higher in the heavier carcasses), whereas meat quality varied little as a result the small variation between carcass weights in sucking lambs.
Effect of forage type and proportion of concentrate in the diet on milk fatty acid composition in cows given sunflower oil and fish oil
Authors: Shingfield K. J. , Reynolds C. K. , Lupoli B. , Toivonen V. , Yurawecz M. P. , Delmonte P. , Griinari J. M. , Grandison A. S. , Beever D. E.
Published: February 2006

Based on the potential benefits ofcis-9,trans-11 conjugated linoleic acid (CLA) for human health there is a need to develop effective strategies for enhancing milk fat CLA concentrations. In this experiment, the effect of forage type and level of concentrate in the diet on milk fatty acid composition was examined in cows given a mixture of fish oil and sunflower oil. Four late lactation Holstein-British Friesian cows were used in a 4 × 4 Latin-square experiment with a 2 × 2 factorial arrangement of treatments and 21-day experimental periods. Treatments consisted of grass (G) or maize (M) silage supplemented with low (L) or high (H) levels of concentrates (65 : 35 and 35 : 65; forage : concentrate ratio, on a dry matter (DM) basis, respectively) offered as a total mixed ration at a restricted level of intake (20 kg DM per day). Lipid supplements (30 g/kg DM) containing fish oil and sunflower oil (2 : 3 w/w) were offered during the last 14 days of each experimental period. Treatments had no effect on total DM intake, milk yield, milk constituent output or milk fat content, but milk protein concentrations were lower (P< 0.05) for G than M diets (mean 43.0 and 47.3 g/kg, respectively). Compared with grass silage, milk fat contained higher (P< 0.05) amounts of C12:0, C14:0, trans C18:1and long chain ≥ C20 (n-3) polyunsaturated fatty acids (PUFA) and lower (P< 0.05) levels of C18:0and trans C18:2when maize silage was offered. Increases in the proportion of concentrate in the diet elevated (P< 0.05) C18:2(n-6) and long chain ≥ C20 (n-3) PUFA content, but reduced (P< 0.05) the amount of C18:3(n-3). Concentrations oftrans-11 C18:1in milk were independent of forage type, but tended (P< 0.10) to be lower for high concentrate diets (mean 7.2 and 4.0 g/100 g fatty acids, for L and H respectively). Concentrations oftrans-10 C18:1were higher (P< 0.05) in milk from maize compared with grass silage (mean 10.3 and 4.1 g/100 g fatty acids, respectively) and increased in response to high levels of concentrates in the diet (mean 4.1 and 10.3 g/100 g fatty acids, for L and H, respectively). Forage type had no effect (P> 0.05) on total milk conjugated linoleic acid (CLA) (2.7 and 2.8 g/100 g fatty acids, for M and G, respectively) orcis-9,trans-11 CLA content (2.2 and 2.4 g/100 g fatty acids). Feeding high concentrate diets tended (P< 0.10) to decrease total CLA (3.3 and 2.2 g/100 g fatty acids, for L and H, respectively) andcis-9,trans-11 CLA (2.9 and 1.7 g/100 g fatty acids) concentrations and increase milktrans-9,cis-11 CLA andtrans-10,cis-12 CLA content. In conclusion, the basal diet is an important determinant of milk fatty acid composition when a supplement of fish oil and sunflower oil is given.
Inbreeding – lessons from animal breeding, evolutionary biology and conservation genetics
Authors: Kristensen T. N. , Sørensen A. C.
Published: February 2006

Abstract Increased rates of inbreeding are one side effect of breeding programmes designed to give genetic progress for traits of economic importance in livestock. Inbreeding leads to inbreeding depression for traits showing dominance, and will ultimately lead to a decrease in genetic variance within populations. Here we review theoretical and experimental literature from animal breeding, evolutionary biology and conservation genetics on the consequences of inbreeding in terms of trait means and genetic and environmental variance components. The genetic background for these effects is presented and the experimental literature interpreted in relation to them. Furthermore, purging of deleterious alleles and the variable nature of effects of inbreeding on populations are discussed. Based on the literature, we conclude that inbreeding in animal breeding must be controlled very efficiently to maintain long-term sustainable livestock production in the future. The tools to do this efficiently exist, and much can be learnt on inbreeding from the literature in fields only distantly related to animal breeding.
Generic and site‐specific criteria in assessment of human health risk from contaminated soil
Authors: Nathanail C.P.
Published: February 2006

Abstract. Previous industrial and waste disposal activities and natural processes have led to elevated concentrations of harmful substances in soil. Risk‐based land management requires the risk posed by such substances to be managed. Generic assessment criteria offer a simple and efficient but often over‐cautious approach to human health risk assessment. Site‐specific assessment criteria reduce over‐conservatism but require extra time and effort to determine. Generic assessment criteria should represent contaminant concentrations below which there is no unacceptable risk to human health. Consistent definitions, application and interpretation are essential prerequisites for fostering and maintaining stakeholder confidence in risk‐based land management.
Assessing exposure to pedogenic arsenic contamination at a dwelling in Northamptonshire, UK: a case study
Authors: Nathanail C.P. , McCaffrey C. , Haynes D.
Published: February 2006

Abstract. Soil associated with Northampton Sand within the area of the Borough Council of Wellingborough has elevated levels of arsenic. Arsenic in such soil at a private dwelling was analysed to determine the arsenic oral bioavailability and uptake by fruit and vegetables grown at the site. This information was used to assess the risk to a present occupant with 22 years' exposure, and to a 0–6‐year‐old girl, the critical receptor in the standard residential land use as stated in UK policy. The exposure pathways comprised soil and dust ingestion, consumption of home‐grown vegetables and ingestion of soil attached to home‐grown fruit and vegetables. The soil guideline value (SGV) for arsenic in residential land use with plant uptake derived using the Contaminated Land Exposure Assessment (CLEA) model was deemed inappropriate for use at this site, since the SGV does not include the consumption of home‐grown fruit, potentially a major pathway in this site for the current occupant, and also assumes 100% arsenic bioavailability. Hence, it was necessary to derive site‐specific assessment criteria for arsenic, for which we used the first edition of the Scotland and Northern Ireland Forum for Environmental Research (SNIFFER) framework, modified to reflect guidance in Contaminated Land Research (CLR) Reports CLR 9 and 10, and to incorporate the consumption of home‐grown fruit. The incorporation of site‐specific data on arsenic bioavailability and vegetable: soil arsenic concentration factor for the 0–6‐year‐old receptor gave a site‐specific assessment criterion (SSAC) of 139 mg kg−1 soil. For the adult female receptor, incorporating the site‐specific data on arsenic bioavailability, the vegetable: soil and the fruit: soil concentration factors gave a SSAC of 251 mg kg−1 soil. In both cases, the vegetable consumption pathway drives the risk. None of the 19 soil sample results for arsenic exceeded the site‐specific assessment criteria derived for the current occupiers, but 13 of the soil samples slightly exceeded the site‐specific assessment criteria for the putative 0–6‐year‐old girl. Given the degree of conservatism in the selection of input values for the exposure parameters in the SNIFFER framework, this exceedance was not considered to warrant further regulatory action at the time.
Two efficient algorithms for the computation of ideal sums in quadratic orders
Authors: Weilert André
Published: February 2006

This paper deals with two different asymptotically fast algorithms for the computation of ideal sums in quadratic orders. If the class number of the quadratic number field is equal to 1, these algorithms can be used to calculate the GCD in the quadratic order. We show that the calculation of an ideal sum in a fixed quadratic order can be done as fast as inZ\mathbf {Z}up to a constant factor, i.e., inO(μ(n)log⁡n),O(\mu (n) \log n),wherennbounds the size of the operands andμ(n)\mu (n)denotes an upper bound for the multiplication time ofnn-bit integers. Using Schönhage–Strassen’s asymptotically fast multiplication fornn-bit integers, we achieve 𝜇(𝑛)=𝑂(𝑛log𝑛loglog𝑛).
Linear law for the logarithms of the Riemann periods at simple critical zeta zeros
Authors: Broughan Kevin , Barnett A.
Published: February 2006

Each simple zero

1
2

+
i

γ
n

\frac {1}{2}+i\gamma _n

of the Riemann zeta function on the critical line with

γ
n

>
0

\gamma _n > 0

is a center for the flow

s
˙

=
ξ
(
s
)

\dot {s}=\xi (s)

of the Riemann xi function with an associated period

T
n

T_n

. It is shown that, as

γ
n

→
∞

\gamma _n \rightarrow \infty

,
\[

log
⁡

T
n

≥

π
4

γ
n

+
O
(
log
⁡

γ
n

)
.

\log T_n\ge \frac {\pi }{4}\gamma _n+O(\log \gamma _n).

\]
Numerical evaluation leads to the conjecture that this inequality can be replaced by an equality. Assuming the Riemann Hypothesis and a zeta zero separation conjecture

γ

n
+
1

−

γ
n

≫

γ
n

−
θ

\gamma _{n+1}-\gamma _n \gg \gamma _n^{-\theta }

for some exponent

θ
>
0

\theta >0

, we obtain the upper bound

log
⁡

T
n

≪

γ
n

2
+
θ

\log T_n \ll \gamma ^{2+\theta }_n

. Assuming a weakened form of a conjecture of Gonek, giving a bound for the reciprocal of the derivative of zeta at each zero, we obtain the expected upper bound for the periods so, conditionally,

log
⁡

T
n

=

π
4

γ
n

+
O
(
log
⁡

γ
n

)

\log T_n = \frac {\pi }{4}\gamma _n+O(\log \gamma _n)

. Indeed, this linear relationship is equivalent to the given weakened conjecture, which implies the zero separation conjecture, provided the exponent is sufficiently large. The frequencies corresponding to the periods relate to natural eigenvalues for the Hilbert–Polya conjecture. They may provide a goal for those seeking a self-adjoint operator related to the Riemann hypothesis.
Hermite methods for hyperbolic initial-boundary value problems
Authors: Goodrich John , Hagstrom Thomas , Lorenz Jens
Published: February 2006

We study arbitrary-order Hermite difference methods for the numerical solution of initial-boundary value problems for symmetric hyperbolic systems. These differ from standard difference methods in that derivative data (or equivalently local polynomial expansions) are carried at each grid point. Time-stepping is achieved using staggered grids and Taylor series. We prove that methods using derivatives of order

m
m

in each coordinate direction are stable under

m
m

-independent CFL constraints and converge at order

2
m
+
1

2m+1

. The stability proof relies on the fact that the Hermite interpolation process generally decreases a seminorm of the solution. We present numerical experiments demonstrating the resolution of the methods for large

m
m

as well as illustrating the basic theoretical results.
Specialized Runge-Kutta methods for index 2 differential-algebraic equations
Authors: Jay Laurent
Published: February 2006

We consider the numerical solution of systems of semi-explicit index

2
2

differential-algebraic equations (DAEs) by methods based on Runge-Kutta (RK) coefficients. For nonstiffly accurate RK coefficients, such as Gauss and Radau IA coefficients, the standard application of implicit RK methods is generally not superconvergent. To reestablish superconvergence projected RK methods and partitioned RK methods have been proposed. In this paper we propose a simple alternative which does not require any extra projection step and does not use any additional internal stage. Moreover, symmetry of Gauss methods is preserved. The main idea is to replace the satisfaction of the constraints at the internal stages in the standard definition by enforcing specific linear combinations of the constraints at the numerical solution and at the internal stages to vanish. We call these methods specialized Runge-Kutta methods for index

2
2

DAEs (SRK-DAE 

2
2

).
A nonlinear approach to absorbing boundary conditions for the semilinear wave equation
Authors: Szeftel Jérémie
Published: February 2006

We construct a family of absorbing boundary conditions for the semilinear wave equation. Our principal tool is the paradifferential calculus which enables us to deal with nonlinear terms. We show that the corresponding initial boundary value problems are well posed. We finally present numerical experiments illustrating the efficiency of the method.
Optimal filter and mollifier for piecewise smooth spectral data
Authors: Tanner Jared
Published: February 2006

We discuss the reconstruction of piecewise smooth data from its (pseudo-) spectral information. Spectral projections enjoy superior resolution provided the function is globally smooth, while the presence of jump discontinuities is responsible for spurious

O

(
1
)

{\mathcal O}(1)

Gibbs’ oscillations in the neighborhood of edges and an overall deterioration of the convergence rate to the unacceptable first order. Classical filters and mollifiers are constructed to have compact support in the Fourier (frequency) and physical (time) spaces respectively, and are dilated by the projection order or the width of the smooth region to maintain this compact support in the appropriate region. Here we construct a noncompactly supported filter and mollifier with optimal joint time-frequency localization for a given number of vanishing moments, resulting in a new fundamental dilation relationship that adaptively links the time and frequency domains. Not giving preference to either space allows for a more balanced error decomposition, which when minimized yields an optimal filter and mollifier that retain the robustness of classical filters, yet obtain true exponential accuracy.
Complexity of inverting the Euler function
Authors: Contini Scott , Croot Ernie , Shparlinski Igor
Published: February 2006

Given an integer

n
n

, how hard is it to find the set of all integers

m
m

such that

φ
(
m
)
=
n

\varphi (m) = n

, where

φ
\varphi

is the Euler totient function? We present a certain basic algorithm which, given the prime number factorization of

n
n

, in polynomial time “on average” (that is,

(
log
⁡
n

)

O
(
1
)

(\log n)^{O(1)}

), finds the set of all such solutions

m
m

. In fact, in the worst case this set of solutions is exponential in

log
⁡
n

\log n

, and so cannot be constructed by a polynomial time algorithm. In the opposite direction, we show, under a widely accepted number theoretic conjecture, that the Partition Problem, an NP-complete problem, can be reduced in polynomial (in the input size) time to the problem of deciding whether

φ
(
m
)
=
n

\varphi (m) = n

has a solution, for polynomially (in the input size of the Partition Problem) many values of

n
n

(where the prime factorizations of these

n
n

are given). What this means is that the problem of deciding whether there even exists a solution

m
m

to

φ
(
m
)
=
n

\varphi (m) = n

, let alone finding any or all such solutions, is very likely to be intractable. Finally, we establish close links between the problem of inverting the Euler function and the integer factorization problem.
Baseline dimensions of the human vagina
Authors: Barnhart Kurt T. , Izquierdo Adriana , Pretorius E. Scott , Shera David M. , Shabbout Mayadah , Shaunik Alka
Published: February 2006

BACKGROUND: Vaginal anatomy has been poorly studied. This study aimed to measure baseline dimensions of the undistended vagina of women of reproductive age. METHODS: We combined baseline information collected from five clinical trials using magnetic resonance imaging (MRI) to quantify distribution of a vaginal gel. Seventy-seven MRI scans were performed on 28 women before gel application to establish baseline vaginal measurements. Average dimensions were calculated for each woman and for the population. The influence of potential covariates (age, height, weight and parity) on these dimensions was assessed. RESULTS: MRI measurements are reproducible. The SD surrounding the mean at each anatomical site, and with summary measurements, was significantly smaller with each subject compared with the population. Mean vaginal length from cervix to introitus was 62.7 mm. Vaginal width was largest in the proximal vagina (32.5 mm), decreased as it passed through the pelvic diaphragm (27.8 mm) and smallest at the introitus (26.2 mm). Significant positive associations were parity with vaginal fornix length, age with pelvic flexure width and the height with width at the pelvic flexure. CONCLUSION: No one description characterized the shape of the human vagina. Although there is variation among women, variables such as parity, age and height are positively associated with differences in baseline dimensions.
An analytical model assessing the potential threat to natural habitats from insect resistance transgenes: continuous transgene input
Authors: Kelly Colleen K , Bowler Michael , Breden Felix
Published: February 2006

The potential effects of ‘escape’ of genetically modified material (transgenes) into natural communities is a major concern in their use. These effects may be limited in the first instance by limiting the proportion of transgene-carrying plants in the natural community. We previously presented an analytical model of the ecological processes governing the relative abundance and persistence of insect resistance (IR) transgenes in a natural community. In that paper, we illustrated the case in which the transgene is input into the community in a single season using data from oilseed rape (OSR) and its known herbivore,
Plutella macropennis
. We found that the transgene is unlikely to have a great impact on the natural community. Here, we extend the model for repeated input of crop pollen carrying the transgene. We show the model output, again using OSR, for continuous input of the transgene over 10 years, the projected commercial lifetime of a transgene without associated undesirable agronomic effects. Our results do not change our original conclusion that the IR transgene need not have a large impact on the natural community and our suggestions for assessing and mitigating any threat still stand.
Drosophila lacking microRNA miR-278 are defective in energy homeostasis
Authors: Teleman Aurelio A. , Cohen Stephen M.
Published: February 2006

The mechanisms that control energy homeostasis and tissue growth during development are closely linked through the insulin signal transduction pathway. Changes in the level of insulin and other hormones reflect the nutritional status of the animal to control circulating sugar levels and fat metabolism. Systemic defects in insulin responsiveness can lead to elevated circulating glucose levels and fat accumulation. Here we present evidence that the microRNA miR-278 plays a role in the control of energy homeostasis in Drosophila. miR-278 mutants have elevated insulin production and are correspondingly lean. Despite the elevated insulin levels, miR-278 mutants have elevated circulating sugar, mobilized from adipose-tissue glycogen stores. We provide evidence that miR-278 mutants are insulin resistant and that miR-278 acts through regulation of the expanded transcript.
First‐line therapy with thalidomide, dexamethasone and zoledronic acid decreases bone resorption markers in patients with multiple myeloma
Authors: Tosi Patrizia , Zamagni Elena , Cellini Claudia , Parente Raffaele , Cangini Delia , Tacchetti Paola , Perrone Giulia , Ceccolini Michela , Boni Paola , Tura Sante , Baccarani Michele , Cavo Michele
Published: February 2006

Abstract:  Background: Bone involvement is frequently observed in multiple myeloma (MM) patients both at diagnosis and during the course of the disease. The evaluation of biochemical markers of bone turnover could allow a dynamic evaluation of the effects of a given therapy on bone metabolism. Methods:  In the present study, markers of bone resorption [urinary free pyridinoline (PYD), deoxypyridinoline (DPYD), N‐terminal telopeptide of collagen I (NTX) and C‐terminal telopeptide (serum crosslaps)] and of bone formation [bone alkaline phosphatase (BAP) and osteocalcin] were evaluated at diagnosis and after induction therapy in 40 patients (23M, 17F, median age = 53.5 yr) enrolled in the ‘Bologna 2002’ clinical trial. By study design, all patients received 4 months of combined thalidomide (100 mg/d for 2 wk then 200 mg/d), dexamethasone (40 mg/d on days 1–4, 9–12, 17–20/28 on odd cycles and on days 1–4 on even cycles) and zoledronic acid (4 mg/28 d). Results: At diagnosis, although bone resorption markers were increased in more than 40% of the patients, only NTX (P = 0.029) and crosslaps (P = 0.000) were significantly related to the extent of skeletal lesions, as assessed by X‐ray. After 4 months of therapy, a significant decrease in mean (±SE) urinary NTX (52.7 ±6.9 nmol/mmol creatinine ±6.9 vs. 14 ± 1.42 nmol/mmol creatinine, P = 0.000) and serum crosslaps (6242.4 ±945 pmol/L vs. 1414.9 ± 173.8 pmol/L, P = 0.000) was observed in patients obtaining ≥partial response, at variance to what has been detected in patients showing <partial response. Conclusions: Among all bone resorption markers, urinary NTX and serum crosslaps seem to be strictly related to the extent of bone involvement in MM. Combined thalidomide + dexamethasone and zoledronic acid seem to be highly effective in reducing bone resorption in sensitive patients, although the relative contribution of each drug cannot yet be determined.
High incidence of myelodysplasia and secondary leukaemia in the UK Medical Research Council Pilot of autografting in chronic lymphocytic leukaemia
Authors: Milligan Donald W. , Kochethu Geothy , Dearden Claire , Matutes Estella , MacConkey Christopher , Catovsky Daniel ,   the UK National Cancer Research Institute (NCRI) Haematological Studies Group
Published: February 2006

We report a high incidence of myelodysplastic syndrome (MDS)/acute myeloid leukaemia (AML) in patients entered into the Medical Research Council Chronic Lymphocytic Leukaemia‐5 trial. Of 115 newly diagnosed patients treated with fludarabine, 65 patients proceeded to autologous transplant. Conditioning was cyclophosphamide and total body irradiation in 49 (75%) patients and chemotherapy in 12 (18%). Ten patients have developed MDS/AML; eight had undergone an autograft. Five‐year actuarial risk of developing MDS/AML postautograft was 12·4% (95% confidence interval, 2·5–24%). No analysed potential risk factor was predictive for MDS/AML development. We hypothesise that potential causative factors are fludarabine, low cell dose and transplant conditioning.