bluuebunny/crossref_metadata_2025 huggingface dataset:
Electron paramagnetic resonance of a donor in aluminum nitride crystals
Authors: Evans S. M. , Giles N. C. , Halliburton L. E. , Slack G. A. , Schujman S. B. , Schowalter L. J.
Published: February 2006

Electron paramagnetic resonance (EPR) and electron-nuclear double resonance (ENDOR) spectra are obtained from a donor in aluminum nitride (AlN) crystals. Although observed in as-grown crystals, exposure to x rays significantly increases the concentration of this center. ENDOR identifies a strong hyperfine interaction with one aluminum neighbor along the c axis and weaker equivalent hyperfine interactions with three additional aluminum neighbors in the basal plane. These aluminum interactions indicate that the responsible center is a deep donor at a nitrogen site. The observed paramagnetic defect is either a neutral oxygen substituting for nitrogen (ON0) or a neutral nitrogen vacancy (VN0).
Thermal stability improvement by using Pd∕NiO∕Al∕Ti∕Au reflective ohmic contacts to p-GaN for flip-chip ultraviolet light-emitting diodes
Authors: Pan Chang-Chi , Chen Guan-Ting , Hsu Wen-Jay , Lin Chih-Wei , Chyi Jen-Inn
Published: February 2006

The thermal stability, optical reflectivity, and contact resistivity of Pd∕NiO∕Al∕Ti∕Au ohmic contacts to p-type GaN were investigated. In contrast to Pd∕Ni∕Al∕Ti∕Au counterparts, the ohmic contacts Pd∕NiO∕Al∕Ti∕Au retained their specific contact resistivity (<3.3×10−2Ωcm2) and high reflectivity (>75% @ 370 nm) after a long thermal aging at 200 °C for 100 h in nitrogen ambient. According to the results of the secondary ion mass spectroscopy in-depth profiles study, it is found that the NiO layer is more transparent and a better diffusion barrier than Ni to prevent the penetration of upper metals into p-type GaN during thermal treatment.
Variable-angle ellipsometry and molecular orientation in monoclinic organic semiconductors
Authors: Tavazzi S. , Campione M.
Published: February 2006

Variable-angle ellipsometry has been used to characterize oligothiophene crystals with principal axes inclined at an angle to the surface normal. The results allow deducing with high sensitivity the orientation of the molecules in these anisotropic and absorbing organic solids, thus allowing one to follow the evolution of the molecular orientation after inducing the transition of the crystallographic structure between the two polymorphs of quaterthiophene. This material is representative of a large class of solids with technological applications in either crystal or thin-film form, where different structural properties and molecular orientation may arise from different preparation conditions.
Deforming nanocrystalline nickel at ultrahigh strain rates
Authors: Wang Y. M. , Bringa E. M. , McNaney J. M. , Victoria M. , Caro A. , Hodge A. M. , Smith R. , Torralva B. , Remington B. A. , Schuh C. A. , Jamarkani H. , Meyers M. A.
Published: February 2006

The deformation mechanism of nanocrystalline Ni (with grain sizes in the range of 30–100 nm) at ultrahigh strain rates (>107s−1) was investigated. A laser-driven compression process was applied to achieve high pressures (20–70 GPa) on nanosecond timescales and thus induce high-strain-rate deformation in the nanocrystalline Ni. Postmortem transmission electron microscopy examinations revealed that the nanocrystalline structures survive the shock deformation, and that dislocation activity is a prevalent deformation mechanism for the grain sizes studied. No deformation twinning was observed even at stresses more than twice the threshold for twin formation in micron-sized polycrystals. These results agree qualitatively with molecular dynamics simulations and suggest that twinning is a difficult event in nanocrystalline Ni under shock-loading conditions.
Self-assembled ternary complexes of neutral liposomes, deoxyribonucleic acid, and bivalent metal cations. Promising vectors for gene transfer?
Authors: Bruni P. , Pisani M. , Amici A. , Marchini C. , Montani M. , Francescangeli O.
Published: February 2006

By means of synchrotron x-ray diffraction we demonstrate the self-assembled formation of the neutral ternary dioleoyl-phosphatidylcholine-deoxyribonucleic acid (plasmid)−Me2+ (Me=Ca and Mn) complexes in the liquid-crystalline Lα phase. We also report an attempt of an in vitro transfection on mouse fibroplast NIH 3T3 cell lines, which shows the capability of these complexes to transfect DNA. Based on the reported results, efficient encapsulation of DNA plasmids in these ternary neutral complexes may represent an important alternative to current systemic gene approaches.
Aberration-free negative-refractive-index lens
Authors: Chen Jiajun , Radu Cosmin , Puri Ashok
Published: February 2006

The aberrations of a spherical lens composed of left-handed materials are studied in this letter. Five Seidel aberrations (spherical, coma, astigmatism, field curvature, and distortion) as a function of the refractive index n and shape factor q of the lens are considered. Our numerical calculations show that the negative refractive index gives much larger windows of small values of aberrations than the positive index, which will significantly enhance the flexibility for the design of an optical lens. Two possible regions with optimized aberrations are proposed: n=−1, q=−2.2 and n=−0.81 and q=0.83.
Ordering of high-quality InAs quantum dots on defect-free nanoholes
Authors: Kim Jong Su , Kawabe Mitsuo , Koguchi Nobuyuki
Published: February 2006

We demonstrate a promising way for the fabrication of high-quality InAs quantum dot (QD) arrays by combining atomic force microscope (AFM) tip-induced nano-oxidation, atomic-hydrogen etching/cleaning (AHE/C), and droplet epitaxy method. The highly aligned defect-free nanoholes as nucleation sites were fabricated by using AFM tip-induced nano-oxidation and subsequent AHE/C. Using the droplet epitaxy on the artificially patterned nanoholes, we fabricated laterally arrayed InAs QDs with an interdot distance of 100nm. The photoluminescence from the InAs QD arrays showed strong emission at 1.22eV, even though the processed interface directly faced the base of the InAs QDs, indicating that the process can reduce the physical and chemical defects/contaminants at the nanoholes and interface.
Reduction of hafnium oxide and hafnium silicate by rhenium and platinum
Authors: Copel M. , Pezzi R. P. , Neumayer D. , Jamison P.
Published: February 2006

We report chemical interactions of Hf-based dielectrics with Re and Pt overlayers during annealing. Reduction of the Hf to a suboxide is observed by x-ray photoelectron spectroscopy, along with a decrease in total oxygen content measured by medium-energy ion scattering. For Re, this unanticipated reaction is highly dependent on the premetallization history of the sample. The presence of hydroxyl groups, observed by infrared absorption, is thought to be responsible. In addition, substantial electrostatic core-level shifts are observed, even in the absence of Hf reduction. The electrostatic shifts are symptomatic of altered threshold voltages for devices.
Crude protein and amino acid composition of honey bee-collected pollen pellets from south-east Australia and a note on laboratory disparity
Authors: Somerville D. C. , Nicol H. I.
Published: February 2006

Pollen pellets collected from honey bees foraging at 62 floral species were analysed for protein and amino acid content and their value for honey bee nutrition was determined. The crude protein levels of all pollen pellets analysed ranged from 9.2% for Hypochoeris radicata (flatweed) to 37.4% for Echium plantagineum (Paterson’s curse) with a mean of 25.9%. Pollen pellets from 15 species were identified as providing protein levels below those acknowledged to satisfy honey bee dietary requirements when they are the only source of pollen available to the honey bee colony. Pollens collected from species of the same genus demonstrated similar protein profiles. Isoleucine was deficient in 38% of the pollens with 69% of eucalypts and related species demonstrating a significant isoleucine deficiency.
Musk deer farming in China
Authors: Xiuxiang Meng , Caiquan Zhou , Jinchu Hu , Cao Li , Zhibin Meng , Jinchao Feng , Yijun Zhou , Yinjiu Zhu
Published: February 2006

Five musk deer species (genus Moschus) are distributed in China, and the present estimated numbers in the wild are between 220 000 and 320 000. Population size of musk deer has dropped significantly due to historical over-hunting and loss or degradation of their habitat. Musk deer farming, therefore, has become one of the most appropriate ways to protect and utilize musk deer resources. In China, musk deer farming and extracting musk from the captive musk deer have been reasonably successful since the early 1950s. At present three species of musk deer, namely forest (Moschus Berezovskii), alpine (M. sifanicus) and Siberian (M. moschiferus) musk deer are farmed in China and, of these, the forest musk deer is the main captive population. The present patterns of musk deer farming in China, however, need to be improved and developed into more economic and scientific modes in order to improve the rate of survival and reproduction, and to increase the production of musk.
Predicting intramuscular fat, moisture and Warner-Bratzler shear force in pork muscle using near infrared reflectance spectroscopy
Authors: Barlocco N. , Vadell A. , Ballesteros F. , Galietta G. , Cozzolino D.
Published: February 2006

Partial least-squares (PLS) models based on visible (Vis) and near infrared reflectance (NIR) spectroscopy data were explored to predict intramuscular fat (IMF), moisture and Warner Bratzler shear force (WBSF) in pork muscles (m. longissimus thoracis) using two sample presentations, namely intact and homogenized. Samples were scanned using a NIR monochromator instrument (NIRSystems 6500, 400 to 2500 nm). Due to the limited number of samples available, calibration models were developed and evaluated using full cross validation. The PLS calibration models developed using homogenized samples and raw spectra yielded a coefficient of determination in calibration (R2) and standard error of cross validation (SECV) for IMF (R2=0·87; SECV=1·8 g/kg), for moisture (R2=0·90; SECV=1·1 g/kg) and for WBSF (R2=0·38; SECV=9·0 N/cm). Intact muscle presentation gave poorer PLS calibration models for IMF and moisture (R2<0·70), however moderate good correlation was found for WBSF (R2=0·64; SECV=8·5 N/cm). Although few samples were used, the results showed the potential of Vis-NIR to predict moisture and IMF using homogenized pork muscles and WBSF in intact samples.
Determination of the optimum dietary lysine concentration for boars and gilts penned in pairs and in groups in the weight range 60 to 100 kg
Authors: O'Connell M. K. , Lynch P. B. , O'Doherty J. V.
Published: February 2006

Three trials were conducted to determine the optimum dietary lysine concentration for maximum growth rate (ADG) or minimum food conversion ratio (FCR) of boars and gilts from 60 to 90 kg (in pairs) and 80 to 100 kg (in pairs or groups). Ninety pairs of pigs and six treatments (dietary lysine concentrations) were used in experiment 1 (60 to 90 kg), 144 pairs and eight treatments in experiment 2 (80 to 100 kg) and groups of 13 pigs (no.=42 groups) and six treatments in experiment 3 (80 to 100 kg). Experiments were arranged as randomized-block designs, blocked on the basis of sex and start weight. Isoenergetic diets (13·8 MJ digestible energy per kg) were based on barley, wheat, soya-bean meal, with added vitamins, minerals and amino acids. Dietary lysine concentrations were: 7·9, 8·8, 9·7, 10·7, 11·7 and 12·5 g/kg in experiment 1; 7·0, 7·9, 8·8, 9·7, 10·7, 11·7, 12·5 and 13·5 g/kg in experiment 2; and 7·0, 7·9, 8·8, 9·7, 10·7 and 11·7 g/kg in experiment 3. In experiment 1 (60 to 90 kg pairs), ADG increased (quadratic, P<0·01) and FCR improved (quadratic, P<0·001) with increased lysine concentration. Although boars grew faster (P<0·001) and were more efficient (P<0·001) than gilts, maximum ADG was predicted at 10·8 g lysine per kg and minimum FCR at 10·9 g lysine per kg for all pigs. In experiment 2 (80 to 100 kg pairs), a treatment×sex interaction for ADG (P<0·01) and FCR (P<0·05) indicated that boars grew faster and had better FCR than gilts at dietary lysine concentrations above 10·7 and 9·7 g/kg respectively, with no difference between the sexes below these lysine levels. Maximum ADG was predicted at 11·8 and 9·9 g lysine per kg and minimum FCR was predicted at 11·9 and 10·0 g lysine per kg for boars and gilts, respectively. In experiment 3 (80 to 100 kg groups) ADG increased (quadratic, P<0·01) and FCR improved (quadratic, P<0·001) as dietary lysine concentration increased. Boars had higher ADG (P<0·001) and better FCR (P<0·001) than gilts. Maximum ADG and minimum FCR were predicted at 9·3 and 9·6 g lysine per kg for all pigs. In conclusion, boars grew faster and more efficiently than gilts, with interactions in experiment 2 indicating a greater difference in performance at higher dietary lysine concentrations.
Effect of dietary structure on animal performance and lesions in the ruminal wall and feet of Belgian Blue double-muscled bulls
Authors: de Campeneere S. , van Herck A. , Fiems L. O. , de Boever J. L. , Chiers K. , Ducatelle R. , de Brabander D. L.
Published: February 2006

The influence of the physical structure level in the diet on animal performance was investigated in 52 Belgian Blue doublemuscled bulls starting from a live weight of 348 kg until slaughter at about 645 kg. Four diets with different concentrate/maize silage ratios were offered ad libitum. The structural value (SV), developed in Belgium as a measure of physical structure in the diet for dairy cows, amounted to respectively 0.63 (HSV; high SV), 0.54 (MSV; moderate SV), 0.43 (LSV; low SV) and 0.34 (VLSV; very low SV) per kg dry matter.

Growth rate, food intake and food conversion were all linearly affected by the decreasing SV of the diet. Among carcass parameters only the SEUROP conformation score showed a significant effect of the SV, with the MSV group having the highest score and VLSV the lowest. No important influence of the SV on the histological damage of the ruminal papillae or on the foot lesions was found.

Based on the lower growth rate and food intake of the LSV group versus the HSV group, a SV of the diet between 0.54 and 0.43 is considered as an absolute minimum for Belgian Blue double-muscled bulls.
Splanchnic metabolism of volatile fatty acids in the dairy cow
Authors: Kristensen N. B.
Published: February 2006

Volatile fatty acids (VFA) are quantitatively important substrates for dairy cows and other ruminants. It has been a central dogma in the nutritional physiology of ruminants that the ruminal epithelium metabolizes a large fraction of VFA during theirabsorption and consequently a relatively small fraction of VFA is available for peripheral tissues including the mammary gland. New data on splanchnic metabolism of VFA indicate that the ruminal epithelium metabolizes none or small amounts of acetate and propionate absorbed from the rumen. However, the ruminal epithelium has a large fractional uptake of butyrate and valerate during their absorption from the rumen. The liver takes up proportionately 0·9 or more of the absorbed propionate, however multiple factors are involved in regulation of hepatic metabolism and propionate does not determine glucose availability to the cowper se. In light of the quantitative importance of VFA to the dairy cow it is important that future research attempts to bridge the gap between the biology of food degradation/digestion in the gastro-intestinal tract and availability of specific nutrients to the cow which impact intermediary metabolism and nutrient utilizationin productive tissues.
Association of body weight, loinlongissimus dorsiand backfat with body condition score in dry and lactating Holstein dairy cows
Authors: Jaurena G. , Moorby J. M. , Fisher W. J. , Cantet R.
Published: February 2006

The lactation cycle of the dairy cow induces large changes in body fat and protein pools, which can be monitored through loin backfat (BF) and longissimus dorsi (LD) measurements. Data from two experiments (exp) using Holstein-Friesian dairy cows (no. = 40 and 32 respectively) were used to study the association of body weight (BW), BF and LD depth with body condition score (BCS) for the last 6 weeks of the dry period (DP) and the first 8 weeks of lactation. Loin and tail BCS were manually assessed (0 to 5 scale) and BF and LD depth were measured by ultrasound at the fifth lumbar process. The BCS data ranged from 1.3 to 3.0 units in the DP, and from about 1.1 to 3.1 units during early lactation in both experiments. Data were analysed by two models: BW, LD or BF = exp + period (DP or lactation) + BCS + interactions + cow + error (model 1); and BCS = exp + period + LD + BF + LD2+ BF2+ exp × LD + exp × BF + exp × LD2+ exp BF2+ period × LD + period × BF + period × LD2+ period × BF2BF2+ cow + error (model 2).

A first-order autoregressive (AR(1)) covariance structure was employed for the error terms to account for the correlation among repeated measures within cow. Regressions of BW and LD on BCS (model 1) found pre- to post-calving differences (P< 0.001) in intercept for BW and LD, and slope coefficients of 35 (DP) and 21 (lactation) kg BW, and 5.8 mm LD per BCS unit. Regression of BF on BCS (model 1) showed an exp × period interaction (P< 0.001), with 0.4 mm BF (exp 1;P< 0.05) and 2.0 mm BF (exp 2;P< 0.001) per BCS unit. Regression of BCS on LD and BF (model 2) showed intercepts not equal to 0 (P< 0.06), and differences (P< 0.001) between DP and lactation; BCS increased (P< 0.001) by 0.027 units per mm BF and 0.05 units per mm LD, but LD had a quadratic term −0.0004 (P= 0.02). It is concluded that at BCS lower than 3, LD contributes to BCS following a quadratic function, whereas BF causes BCS to increase linearly. Each unit of BCS equated to about 35 and 20 kg BW for DP and lactation periods respectively, to 5.8 mm LD, and to between 0.4 and 2.0 mm BF.
Activity pattern and energy expenditure due to physical activity before and during pregnancy in healthy Swedish women
Authors: Lof Marie , Forsum Elisabet
Published: February 2006

Human pregnancy is associated with increased requirements for dietary energy and this increase may be partly offset by reductions in physical activity during gestation. Studies in well-nourished women have shown that the physical activity level (PAL), obtained as the total energy expenditure (TEE) divided by the BMR, decreases in late pregnancy. However, it is not known if this decrease is really caused by reductions in physical activity or if it is the result of decreases in energy expenditure/BMR (the so-called metabolic equivalent, MET) for many activities in late pregnancy. In the present study activity pattern, TEE and BMR were assessed in twenty-three healthy Swedish women before pregnancy as well as in gestational weeks 14 and 32. Activity pattern was assessed using a questionnaire and heart rate recording. TEE was assessed using the doubly labelled water method and BMR was measured by means of indirect calorimetry. When compared to the pre-pregnant value, there was little change in the PAL in gestational week 14 but it was significantly reduced in gestational week 32. Results obtained by means of the questionnaire and by heart rate recording showed that the activity pattern was largely unaffected by pregnancy. The findings support the following conclusion: in a population of well-nourished women where the activity pattern is maintained during pregnancy, the increase in BMR represents approximately the main part of the pregnancy-induced increase in TEE, at least until gestational week 32.
Incorporating turnover in estimates of protein retention efficiency for different body tissues
Authors: Roux C. Z.
Published: February 2006

Formulated in terms of protein synthesis (PS) and protein retention (PR), a definition of turnover-related protein retention efficiency (kP) allows the expression kP=[1+(PS/PR)/6]−1, 6 representing the ratio of the energy equivalent of protein to the cost of synthesis. By combining plausible hormonal and cellular control mechanisms of protein (P) growth, it is possible to derive (PS/PR)=[Q{(P/α)−(4/9)Y−1}]−1+1, allowing the calculation of kPby substitution. The symbol α represents the limit value of protein growth, while the term 4/9 derives from the power in the relationship between the concentration of growth factor-related activator in the nucleus and cell volume (cv). Y is the power in the relationship between cv and total tissue protein, and Q represents the proportion of growth factor-activated nuclei in a tissue. The proportion Q can be estimated from simple functions of intake rates or blood growth factor concentrations. Estimates of Y are derived from histological considerations or calculated from experimental observations; Y=1 for multinucleated skeletal muscle fibres and Y=1/3, 1/2, 1/6 on average for mononucleated cell tissues, skin or bone and viscera, respectively. To apply kPto the whole body, an average value of Y=1/2 can be taken. Experimental observations on tissue protein synthesis and breakdown rates yield direct estimates of kPin satisfactory agreement with comparable theoretical predictions.
The nutritional status of children with cystic fibrosis
Authors: Murphy Alexia J. , Buntain Helen M. , Wainwright Claire E. , Davies Peter S. W.
Published: February 2006

The importance of nutritional intervention for children with cystic fibrosis (CF) is well recognised. It would be expected that the increase in knowledge over the past decade would be reflected in improvements in nutritional status for the CF paediatric population. The aim of the present paper was to evaluate the nutritional status of children with CF, cross-sectionally and longitudinally. Body cell mass adjusted for gender and size (BCM/Htp) was measured in sixty-four children with CF to represent nutritional status and expressed as a Z-score. The cross-sectional results showed a mean BCM/Htp Z-score of 0·54 (sd 1·21), with males having a slightly higher Z-score than females but with a larger variation. At the initial measurement, only one female and one male were considered sub-optimally nourished. The longitudinal analysis after 2 years showed that the mean population had a significantly decreased BCM/Htp Z-score; however, when each gender was analysed separately, this decrease was significant only in the males. At the final measurement, only two females and three males were considered sub-optimally nourished. It is evident from our results that children with CF are well nourished, with only a small percentage considered malnourished. It appears that nutritional status decreases with age, with this decline being more evident in males. These results signify that although children with CF are better nourished with current treatment support, intervention needs to continue throughout a CF patient's life to counteract the changes that occur with age.
Interaction of fish oil and a glucocorticoid on metabolic responses to an oral glucose load in healthy human subjects
Authors: Delarue Jacques , Li Chang-Hong , Cohen Richard , Corporeau Charlotte , Simon Brigitte
Published: February 2006

Compared with saturated fat, n-3 long-chain PUFA-rich fish oil improves insulin sensitivity in rats. We studied whether n-3 long-chain PUFA could prevent insulin resistance induced by dexamethasone (a glucocorticoid) in healthy human volunteers. A group of eight subjects was studied twice after a 2d dexamethasone treatment, before and after a 3-week supplementation with fish oil (providing daily doses of 1·1g 20:5n-3 and 0·7g 22:6n-3). The subjects were studied during the basal state and over the 6h following an oral glucose load (1g/kg). Plasma glucose fluxes were traced with [6,6-2H2]glucose and [13C]glucose (naturally 13C-enriched corn glucose). Substrate oxidation was obtained from indirect calorimetry. Following fish oil supplementation, plasma glucose fluxes and substrate oxidation were maintained despite a 17% reduction (P<0·05) in the area under the curve of plasma insulin response, suggesting an insulin-sensitizing effect.
Time course of the development of non-alcoholic hepatic steatosis in response to high-fat diet-induced obesity in rats
Authors: Gauthier Marie-Soleil , Favier Roland , Lavoie Jean-Marc
Published: February 2006

The aim of the study was to characterize the time course of the development of high-fat diet-induced hepatic steatosis and its relation to body fat accretion and changes in plasma lipid profile. Female Sprague–Dawley rats were high-fat fed (HF; 42%, kJ) for 1, 2, 4, 6, 12 and 16 weeks and compared to standard fed rats (SD). Data obtained from HF rats were further analysed by classifying the animals into obesity-prone and obesity-resistant. In HF rats, liver lipid content increased rapidly by approximately 200% during the first 2 weeks, decreased almost to baseline levels between weeks 2 and 6, and re-increased by 17% between weeks 6 and 16 (P<0·05). Body weight, body fat accretion, plasma leptin, NEFA and glycerol concentrations were higher in HF than in SD rats (P<0·05). These higher values were established in 2 weeks and the differences between the groups did not further enlarge from weeks 2 to 16. Obesity-prone rats depicted higher body weight and body fat accretion than obesity-resistant and SD rats. Surprisingly, however, liver lipid content was the same in obesity-prone as in obesity-resistant rats as they were both higher than in SD rats (weeks 2 and 16;P<0·05). Our data support the hypothesis that the liver acts as a systemic buffer, largely increasing its lipid content in the early stage of high-fat feeding. Our results also suggest that the development of non-alcoholic hepatic steatosis is more linked to dietary fat ingestion than to body weight gain.
Kinetics of the appearance of cereal alkylresorcinols in pig plasma
Authors: Linko Anna-Maria , Ross Alastair B. , Kamal-Eldin Afaf , Serena Anja , Kjær Anna Kirstin Bjørnbak , Jørgensen Henry , Peñalvo José L. , Adlercreutz Herman , Åman Per , Knudsen Knud Erik Bach
Published: February 2006

Alkylresorcinols (AR) are phenolic lipids found in high amounts in wholegrain wheat and rye. They may be important as bioactive components and/or biomarkers of wholegrain wheat and rye intake. AR absorption was studied with pigs during a habitual diet and after a single meal of AR-rich diet. In study 1, four pigs were fed wholegrain rye (RD) and white wheat bread (WD) for 1 week in a cross-over design. Arterial and venous AR concentrations were determined over 540min after feeding on days 5 and 7. In study 2, four pigs were fed a synthetic, starch-based diet for 5d, and arterial and venous AR concentrations were determined over 960min after feeding a single meal of RD. In study 1, plasma AR concentrations after consuming RD peaked at 120min, remained elevated between 120 and 420min, and were re-elevated on refeeding at 480min. In study 2, AR appeared in the plasma after 60min, peaked at 180–240min, and remained elevated after 960min. The apparent elimination half-life was 3·93h, and the maximum plasma concentration was 666 (sem 35) nmol/l. Arterial and venous plasma AR concentrations were similar, suggesting that AR are absorbed via the lymphatic system. AR concentrations in pig plasma increase rapidly after a meal containing AR, and persist in plasma for at least 5d, indicating that AR may be a useful biomarker of wholegrain wheat and rye intake.
Mechanisms involved in the antiplatelet effect of C-phycocyanin
Authors: Chiu Hui-Fen , Yang Shih-Ping , Kuo Yu-Ling , Lai Yuan-Shu , Chou Tz-Chong
Published: February 2006

C-phycocyanin (cpc), a biliprotein isolated fromSpirulina platensis, has been reported to exert many therapeutic and nutritional values. In the present study, we examined whether cpc has an antiplatelet activityin vitroand further investigated the possible anti-aggregatory mechanisms involved. Our results showed that preincubation of cpc (1–50μg/ml) with rabbit washed platelets dose-dependently inhibited the platelet aggregation induced by collagen (10μg/ml) or arachidonic acid (100μm), with an ic50of about 10μg/ml. Furthermore, the thromboxane B2formation caused by collagen or arachidonic acid was significantly inhibited by cpc due to suppression of cyclooxygenase and thromboxane synthase activity. Similarly, the rise of platelet intracellular calcium level stimulated by arachidonic acid and collagen-induced platelet membrane surface glycoprotein IIb/IIIa expression were also attenuated by cpc. In addition, cpc itself significantly increased the platelet membrane fluidity and the cyclic AMP level through inhibiting cyclic AMP phosphodiesterase activity. These findings strongly demonstrate that cpc is an inhibitor of platelet aggregation, which may be associated with mechanisms including inhibition of thromboxane A2formation, intracellular calcium mobilization and platelet surface glycoprotein IIb/IIIa expression accompanied by increasing cyclic AMP formation and platelet membrane fluidity.
Meal-induced insulin sensitization in conscious and anaesthetized rat models comparing liquid mixed meal with glucose and sucrose
Authors: Sadri Parissa , Reid Maria A. G. , Afonso Ricardo A. , Schafer Joshua , Legare Dallas J. , Macedo M. Paula , Lautt W. Wayne
Published: February 2006

We have recently shown that meal-induced insulin sensitization (MIS) occurs after feeding and decreases progressively to insignificance after 24h of fasting and is caused by action of a hepatic insulin sensitizing substance (HISS). In order to carry out quantitative studies of MIS, some standardized meal intake is required. Our objective was to establish animal models to be tested in both the conscious and anaesthetized state using intragastric injection of liquid meals in order to quantify MIS. Insulin sensitivity was assessed before and 90min after the meal using the rapid insulin sensitivity test (RIST) which is a transient euglycaemic clamp. Rats tested in the conscious state were instrumented under anaesthesia 6–9d prior to testing with catheters in the carotid artery, jugular vein and stomach. Meals, injected into the stomach, consisted of a liquid mixed meal, sucrose, glucose or water. The glucose sequestration in response to insulin increased by 90% and 61% following the liquid mixed meal (10ml/kg) in conscious and anaesthetized rats, respectively. Glucose, sucrose and water did not effectively activate MIS. MIS was completely reversed in the conscious model by atropine and completely prevented from developing in the anaesthetized model that had previously undergone hepatic denervation. Gastric administration of a liquid mixed meal but not glucose or sucrose is capable of activating MIS for purposes of mechanistic studies and quantification of the MIS process. The feeding signal is mediated by the hepatic parasympathetic nerves.
Effect of soya protein on serum lipid profile and lipoprotein concentrations in patients undergoing hypercholesterolaemic haemodialysis
Authors: Chen Shu-Tzu , Chen Jiun-Rong , Yang Chwei-Shiun , Peng Sheng-Jeng , Ferng Shyang-Hwa
Published: February 2006

Clinical trials have shown that soya protein reduces the concentrations of some atherogenic lipids in subjects with normal renal function. The present study examined the effects of soya protein on serum lipid concentrations and lipoprotein metabolism in patients on hypercholesterolaemic haemodialysis. Twenty-six hypercholesterolaemic (total cholesterol ≥6·21mmol/l) patients on haemodialysis were studied in a randomized, double-blind, placebo-controlled clinical trial. After a 4-week run-in phase, the subjects were randomly assigned to two groups. Isolated soya protein or milk protein 30g was consumed daily as a beverage at breakfast or post-dialysis for 12 weeks. Soya protein substitution resulted in significant reductions in total cholesterol (17·2 (sd8·9)%), LDL-cholesterol (15·3 (sd12·5)), apo B (14·6 (sd12·1)%) and insulin (23·8 (sd18·7)%) concentrations. There were no significant changes in HDL-cholesterol or apo A-I. These results indicate that replacing part of the daily protein intake with soya protein has a beneficial effect on atherogenic lipids and favourably affects lipoprotein metabolism in hypercholesterolaemic patients undergoing haemodialysis.
Lupin kernel fibre foods improve bowel function and beneficially modify some putative faecal risk factors for colon cancer in men
Authors: Johnson Stuart K. , Chua Veronica , Hall Ramon S. , Baxter Amynta L.
Published: February 2006

Consumption of some dietary fibres may benefit bowel health; however, the effect of Australian sweet lupin (Lupinus angustifolius) kernel fibre (LKFibre) is unknown. The present study examined the effect of a high-fibre diet containing LKFibre on bowel function and faecal putative risk factors for colon cancer compared to a control diet without LKFibre. Thirty-eight free-living, healthy men consumed an LKFibre and a control diet for 1 month each in a single-blind, randomized, crossover study. Depending on subject energy intake, the LKFibre diet was designed to provide 17–30g/d fibre (in experimental foods) above that of the control diet. Bowel function self-perception, frequency of defecation, transit time, faecal output, pH and moisture, faecal levels of SCFA and ammonia, and faecal bacterial β-glucuronidase activity were assessed. In comparison to the control diet, the LKFibre diet increased frequency of defecation by 0·13 events/d (P=0·047), increased faecal output by 21% (P=0·020) and increased faecal moisture content by 1·6% units (P=0·027), whilst decreasing transit time by 17% (P=0·012) and decreasing faecal pH by 0·26 units (P<0·001). Faecal butyrate concentration was increased by 16% (P=0·006), butyrate output was increased by 40% (P=0·002)and β-glucuronidase activity was lowered by 1·4μmol/h per g wet faeces compared to the control diet (P<0·001). Addition of LKFibre to the diet incorporated into food products improved some markers of healthy bowel function and colon cancer risk in men.
A survey of waterfowl for echinostomes and schistosomes from Lake Wanaka and the Waitaki River watershed, New Zealand
Authors: Davis N.E.
Published: February 2006

Waterfowl from Lake Wanaka and the Waitaki Lakes watershed of New Zealand's South Island were surveyed to find natural hosts with adult echinostomes and schistosomes to provide sufficient numbers of eggs for laboratory studies. The Canada goose (Branta canadensis) was found to host an echinostome determined to be a New Zealand strain of Echinostoma revolutum. The New Zealand scaup (Aythya novaeseelandia) concurrently hosts three species of echinostomes (E. revolutum, Echinoparyphium cinctum and E. recurvatum) plus two species of avian schistosomes (Trichobilharzia sp. and Dendritobilharzia pulverulenta). In the Canada goose and the New Zealand scaup, adult gravid echinostomes predominated over juveniles. In other waterfowl surveyed, very few echinostomes were found, with juveniles predominating.
Enzyme-linked immunosorbent assay with worm vomit and cercarial secretions of Schistosoma mansoni to detect infections in an endemic focus of Burkina Faso
Authors: Bahgat M. , Sorgho H. , Ouédraogo J.B. , Poda J.N. , Sawadogo L. , Ruppel A.
Published: February 2006

Cercariae and adult Schistosoma mansoni were used to prepare, respectively, cercarial secretions (CS) and worm vomit (WoV). These were used as antigens in an enzyme-linked immunosorbent assay (ELISA) to test the IgG-reactivity of sera obtained in an S. mansoni-endemic area of Burkina Faso. Among the egg-excreting individuals (n=240), 94.6% reacted positively with WoV, but only 62.9% with CS, thus suggesting a high diagnostic sensitivity of WoV, but not of CS. Among those individuals without detectable eggs in two Kato-Katz thick smears from different stool specimens (n=215), the respective percentages of positive IgG reactivity were 78.1% and 63.3%. These positive reactions in the absence of detectable eggs are interpreted in terms of limited sensitivity of parasitological stool examinations. Optical density values in ELISA with CS, but not with WoV, correlated negatively with age, which may reflect decreasing exposure to cercariae in older individuals.
Prevalence of amphistomiasis and its association with Fasciola gigantica infections in Zambian cattle from communal grazing areas
Authors: Phiri A.M. , Phiri I.K. , Monrad J.
Published: February 2006

To estimate prevalence of amphistomiasis and its association with bovine Fasciola gigantica infections in Zambia, 709 faeces of cattle presented for slaughter from three major cattle rearing areas of Central, Southern and Western provinces were analysed. The prevalence rate of amphistomes was 51.6%. Egg counts per gram (EPG) of faeces ranged from 0 to 385 with a mean (± SEM) of 11.96±1.07. The origin of the cattle had a significant influence (P<0.001) on the prevalence rate. Fasciola gigantica infections accounted for 46.7% of the cattle examined. The mean EPG count (± SEM) was 6.3±0.66 with a range of 0 to 223. A total of 34.6% were mixed infections while single Fasciola and amphistome infections represented 12.1% and 17.1%, respectively. Significantly more cattle (63.8%) were infected with either single or both trematode infections (P<0.0001) than not. Mixed trematode infections were highest in the Southern province (80.0%) while the lowest were recorded in Central province (16.3%). A positive correlation (r2=0.0428) was present in mixed infections. In order to minimize losses, epidemiology and cross-resistance of amphistomiasis and fascioliasis should be studied in different ecological regions of Zambia to formulate efficient control programmes.
Assessment of routine inspection methods for porcine cysticercosis in Zambian village pigs
Authors: Phiri I.K. , Dorny P. , Gabriel S. , Willingham A.L. , Sikasunge C. , Siziya S. , Vercruysse J.
Published: February 2006

The value of tongue and meat inspection as diagnostic tools for porcine cysticercosis was assessed in 65 Zambian village pigs by comparing the results with carcass dissections. In addition, the intensity of infections, distribution and viability of cysts in infected pigs were measured. Five pigs (7.7%) were positive on tongue examination, while routine meat inspection showed 12 (18.5%) positives. However, carcass dissections detected cysticerci in 31 (47.7%) pigs. The range in number of cysticerci was 1 to 14,662 per carcass. Cysticerci were distributed throughout the carcass with the highest concentration in the heart, tongue and hind legs. In one animal 13 viable cysts were detected only in the brain. Fourteen pigs had more than 100 viable cysts, six between 2 and 100, and four had single cyst infections. Seven animals harboured only calcified cysts. These findings demonstrate the serious shortcomings of routine detection methods for porcine cysticercosis. While the specificity of tongue palpation and meat inspection was 100%, these tests failed to detect the infection in 83.9% and 61.3% of infected pigs, respectively.
Plasma etching and ashing: a technique for demonstrating internal structures of helminths using scanning electron microscopy
Authors: Veltkamp C.J. , Chubb J.C.
Published: February 2006

Plasma etching and ashing for demonstrating the three-dimensional ultrastructure of the internal organs of helminths is described. Adult worms of the cestode Caryophyllaeides fennica were dehydrated through an ethanol series, critical point dried (Polaron E3000) and sputter coated with 60% gold-palladium (Polaron E5100) and glued to a standard scanning electron microscope (SEM) stub positioned as required for ashing. After initial SEM viewing of worm surfaces for orientation, stubs were placed individually in the reactor chamber of a PT7150 plasma etching and ashing machine. Worms were exposed to a radio frequency (RF) potential in a low pressure (0.2 mbar) oxygen atmosphere at room temperature. The oxidation process was controlled by varying the times of exposure to the RF potential between 2 to 30 min, depending on the depth of surface tissue to be removed to expose target organs or tissues. After each exposure the oxidized layer was blown from the surface with compressed air, the specimen sputter-coated, and viewed by SEM. The procedure was repeated as necessary, to progressively expose successive layers. Fine details of organs, cells within, and cell contents were revealed. Ashing has the advantage of providing three dimensional images of the arrangement of organs that are impossible to visualize by any other procedure, for example facilitating testes counts in cestodes. Both freshly-fixed and long-term stored helminths can be ashed. Ashing times to obtain the desired results were determined by trial so that some duplicate material was needed.
Changes in FaRP-like peptide levels during development of eggs from the plant-parasitic cyst nematode, Heterodera glycines
Authors: Masler E.P.
Published: February 2006

The plant-parasitic cyst nematode Heterodera glycines requires a host plant to complete its life cycle, which involves hatching of infective juveniles that parasitize through root entry. A laboratory population of H. glycines grown on soybean, Glycine max, undergoes a sharp increase in maturity between 5 and 6 weeks in culture, as measured by the proportion of eggs containing well developed pre-hatch juveniles (late development eggs) versus eggs without visible juveniles (early development eggs). The median percent of eggs classified as late development, representing all samples taken from 4 to 7 weeks in culture, was 61%. For all samples taken up to 5 weeks, 80% scored below the median. In samples taken after 5 weeks, 15% scored below the median. This shift in population maturity was accompanied by a significant increase (P < 0.01) in the number of hatched juveniles present in each sample. There was also a significant increase (P < 0.02) in amount of FaRP-like peptide detected by specific ELISA. Total FaRP levels increased from 0.18 ± 0.07 fMol FLRFamide equivalents per ng protein in early development eggs to 0.40 ± 0.17 in late development eggs. The level remained high in hatched juveniles. HPLC/ELISA detected as many as nine potential FaRPs in H. glycines, two of which were specifically increased (P < 0.005) in hatched juveniles. The association of FaRPs with maturing eggs and the possible involvement of these neuropeptides with juvenile hatching and motility are discussed.
Sampling strategies for contaminated brownfield sites
Authors: Taylor P.D. , Ramsey M.H.
Published: February 2006

Abstract. Brownfield sites often require a geochemical survey to assess the extent of contamination that is present as a result of previous industrial activities. These measurements are subsequently assessed to ascertain whether the site presents the possibility of causing significant harm to those who may use the site for specified purposes. The measurement process comprises both field sampling and chemical analysis, with sampling being of crucial importance, since previous studies have repeatedly shown that it is the sampling phase that generates the highest component of uncertainty. A variety of methods are currently available for sampling brownfield sites, such as different sampling patterns and the choice of depth and mass recovered. An investigator may also choose to employ more innovative sampling methods, such as in situ measurement strategies that can significantly reduce the overall time taken to complete the survey. The general aim of a sampling strategy is to take representative samples for chemical analysis, although this is rarely achieved due to the inherent heterogeneity of contaminants within any given site. Since it is practically impossible to sample an entire site, and thus achieve a truly representative sample, it is becoming increasingly understood that the uncertainty of the measurements should be estimated, to provide a more reliable interpretation of the survey. Various methods are currently available to estimate the measurement uncertainty that arises from both sampling and analysis, which vary in terms of complexity and cost. The level of uncertainty estimated during a site investigation should also be judged on its fitness‐for‐purpose (i.e. whether subsequent decisions based upon it are acceptable). The ‘optimized contaminated land investigation’ (OCLI) method is a new approach that can be used to balance the site‐specific variables of any given investigation, such as the measurement costs against the level of uncertainty and costs that may arise from misclassification. This provides an objective and traceable judgement of whether the measurements are fit‐for‐purpose.
Assessing significant harm to terrestrial ecosystems from contaminated land
Authors: Smith R. , Pollard S.J.T. , Weeks J.M. , Nathanail C.P.
Published: February 2006

Abstract. Terrestrial ecosystem risk assessment remains in its infancy by comparison with the aquatic discipline, yet it is advancing quickly in response to increasing concerns surrounding soil quality and the sustainable use of soil. Several international frameworks have been developed during the last decade to aid decision‐makers as the need for scientifically derived tools for determining ecological risk from land contamination has been recognized. From the regulatory viewpoint, the priority is establishing what to protect in order to prevent ecological harm. This is a complex issue requiring clear objectives in a risk assessment context. The most important factor in assessing ecological harm is whether or not ecosystem function is altered as a result of land contamination and, if it is, judging the significance. A consensus is developing that ecological risk assessment should aim to protect populations rather than individuals. This paper critically reviews recent developments in risk assessment for terrestrial ecosystems and land contamination in the UK, with emphasis on deriving a measure of ecological harm to assess ecosystem function. We seek to further justify the use of earthworms as a favoured indicator species for protecting ecological function. Guidance on how to measure harm in relation to ecological function is, however, still lacking.