bluuebunny/crossref_metadata_2025 huggingface dataset:
Edible composite films of wheat gluten and lipids: water vapour permeability and other physical properties
Authors: GONTARD NATHALIE , DUCHEZ CHRISTOPHE , CUQ JEAN‐LOUIS , GUILBERT STÉPHANE
Published: July 2010

Edible composite films comprised of wheat gluten as the structural matrix and various concentrations of different lipids as the moisture barrier component were tested for water vapour permeability, dispersion in water, opacity and mechanical properties. the effects of lipids on the functional properties of gluten‐based composite films depended on the lipid characteristics and on the interactions between the lipid and the protein structural matrix. Beeswax, a solid and highly hydrophobic lipid, was the most effective lipid for improving moisture barrier properties of films; but these films were opaque, weak and disintegrated easily in water. Combining wheat gluten proteins with a diacetyl tartaric ester of monoglycerides reduced water vapour permeability, increased strength and maintained transparency.
Kinetics of water vapour sorption by drum‐dried banana
Authors: BORGES SORAIA V. , CAL‐VIDAL JOSÉ
Published: July 2010

The kinetics of water vapour sorption of drum‐dried banana was determined at several conditions of temperature (10, 22, 30 and 40°C) and relative humidity (31–97%). For relative humidities below 75% there was a large reduction in sorption rate for a small amount of water absorbed. This type of product presents a very porous structure.
Detection of hepatitis A virus in oysters
Authors: VAN CUYCK‐GANDRE HÉLÉNE , GRATIER DANIELLE , BURCKHART MARIE FRANCE , CRANCE JEAN MARC , SCHWARTZBROD LOUIS
Published: July 2010

A digoxigenin‐labelled RNA probe with a sensitivity of 800 50% tissue culture infectious dose (TCID50) was used to detect Hepatitis A Virus (HAV) in oysters. We studied the influence of extraction methodology on riboprobe detection. Oyster samples obtained by four methods of extraction and extraction‐concentration were spiked with HAV (CF53 strain). There was no correlation between protein concentration and turbidity of samples, and anti‐digoxigenin antibodies showed a non specific reaction. Background noise was independent of protein concentration and disappeared when HAV RNA isolation by phenol/chloroform extraction was introduced, but HAV RNA could not be detected by this technique. In the presence of Acid Guanidinium Thiocyanate (AGT), RNA from HAV suspension was detected following phenolic extraction with a detection threshold of 8.104 TCID50 of spotted virus. HAV detection in oyster extract by a digoxigenin‐labelled riboprobe appeared useful in shellfish virology, at least for a primary screening of samples.
Functional properties of chhana whey powders
Authors: JINDAL ANITA R. , GRANDISON ALISTAIR S.
Published: July 2010

The protein solubility, emulsifying, foaming and gelation properties, and viscosity of solutions of chhana whey protein powders, produced by ultrafiltration and reverse osmosis followed by drying, were studied over the pH range 2.5–9.0. Protein solubility varied from 57–100% and was greatest at low pH values. Chhana whey protein powders had similar emulsifying properties to commercial cheese whey protein powders of similar protein content, although the capacity to form gels when heated to 80°C was much lower, particularly at alkaline pH. the viscosity of solutions of the chhana whey powders was sensitive to pH, but was particularly high in the acidic range. These studies demonstrate considerable potential for the utilization of chhana whey, products in the food industry.
Egg white powder in extruded fish crackers
Authors: JULIANTY JUJUN , BELO PANFILO , SMITH ELVEDA , McPROUD LUCY
Published: July 2010

Four levels of egg white powder (EWP), 0, 1.5, 3.0 and 4.5%, were added to fisfc cracker formulation consisting of tapioca starch, fish paste, and water. the mixture was extruded through a single screw extruder, and the extrudate was cut, dried, heated in a microwave, and the degrees of expansion, bulk density, colour and protein content were measured.

The addition of 1.5 and 3.0% EWP had no significant effect (P < 0.01) on diametral and longitudinal expansion, however, 4.5% EWP significantly (P < 0.01) reduced them. Bulk density and protein content of the final product increased as the percentage of EWP increased in the formulation. the total colour difference measurement showed a significant increase (P < 0.01) in brown colouration at 4.5% EWP.
Gas exchange in modified atmosphere packaging. 2: Experimental results with strawberries
Authors: RENAULT PIERRE , HOUAL LYDIE , JACQUEMIN GUY , CHAMBROY YVES
Published: July 2010

Strawberries were used to test a new model describing gas transport through micro‐perforated polypropylene films and fruit respiration involved in modified atmosphere packaging. Some experiments were conducted with empty packs initially filled with either 100% N2 or 100% O2. Simulations agreed very well with experiments only if we replaced the cross‐sectional area of the micro‐perforations by areas of approximately half the actual areas in order to account for the resistance of air around the perforations. It is also possible to fit the model to gas concentration changes in packs filled with strawberries, although deviations have been due to the contamination of strawberries by fungi. the model was used to quantify the consequences of the variability of pack properties (number of micro‐perforations per pack and cross‐sectional area of these perforations) on equilibrium gas concentrations and to define minimum homogeneity requirements for modified atmosphere packaging.
Elimination of Listeria monocytogenes in soft and red smear cheeses by irradiation with low energy electrons
Authors: ENNAHAR SAÏD , KUNTZ FLORENT , STRASSER ALAIN , BERGAENTZLE MARTINE , HASSELMANN CLAUDE , STAHL VALÉRIE
Published: July 2010

Soft and red smear cheeses are frequently contaminated by Listeria monocytogenes, sometimes at relatively high concentration (< 105 CFUg‐1). This bacterium is radiosensitive (D10 value of approximately 0.45 kGy) but irradiation of the whole cheese by X‐rays induced off‐flavours when the dose exceeded 1.0 kGy. Irradiation could be effective in eliminating L. monocytogenes only from lightly contaminated cheeses (> 102CFU g‐1).

L. monocytogenes appears only in the rind (where the pH is greater than 6.3) and never grows in the core of the cheese. Under these conditions, a specific irradiation of the rind after ripening, with a low‐energy electron beam at relatively high doses (up to 3.0 kGy), allows the total elimination of L. monocytogenes in heavily contaminated samples (105‐106 CFU g‐1) without noticeable modifications of the organoleptic properties of the cheese.
Effect of processing on in vitro digestibility of protein and starch in quinoa seeds
Authors: RUALES JENNY , NAIR BABOO M.
Published: July 2010

The in vitro digestibility of protein in raw quinoa assessed by an enzymic method was 78%, significantly (P > 0.01) lower than that of casein, 91%, and also somewhat lower (P > 0.01) than that of the raw washed quinoa sample, 83%. the process used to remove the outer layers of the seeds containing saponins increased the protein digestibility significantly (P > 0.01), by 7%. Heat treatments increased protein digestibility over that of raw quinoa samples. Only the cooked sample treated for 60 min presented a slightly lower protein digestibility, 77%, than those obtained for other heat‐treated samples.

The temperature, time and moisture used in cooking and autoclaving of whole seeds of quinoa did not improve starch digestibility significantly. the digestibility of the starch in the raw and precooked samples was 72 and 77%, respectively, after drum drying and about 64% after extrusion in both cases. Precooking at 60°C for 20 min does not improve the digestibility of the quinoa starch.
Effect of operating conditions on physical characteristics of extruded rice starch
Authors: TOMÁS RUI L. , OLIVEIRA JORGE C. , AKDOGAN HULYA , McCARTHY KATHRYN L.
Published: July 2010

The effect of screw speed, flow rate, barrel temperature and added moisture on physical characteristics of high moisture extruded rice starch was studied. the product physical characterization was made by measuring density, final moisture content and the maximum load force in a puncture test. Rice flour containing approximately 1.5% protein and 6% moisture was mixed with 55–65% (w/w) water and extruded in a co‐rotating twin screw extruder with a slit die. A two level factorial design was used to analyse each parameter. It was found that added moisture was the most important variable affecting the force‐deformation curve maxima, with the interaction between added moisture and barrel temperature exhibiting a less significant effect. Added moisture and flow rate each affected density, with the interaction between added moisture and screw speed showing a less significant effect. Temperature and flow rate affected final moisture interactively with added moisture, which was evidently the most important variable.
A simple and rapid antibody‐capture ELISA for the detection of staphylococcal enterotoxin A in food including a simple extraction step
Authors: DE OLIVEIRA TEREZA CRISTINA R.M. , LEE HEATHER A. , WYATT GARY , HIROOKA ELISA Y. , MORGAN MICHAEL R.A.
Published: July 2010

A sensitive and precise ELISA for the detection of staphylococcal enterotoxin A in food has been developed, using specific IgG anti‐toxin antibodies purified from immunized rabbits. an antibody capture format was found to be the most useful following cross‐reaction and sensitivity studies. the ELISA was used to investigate concentration of staphylococcal enterotoxin A from food samples by polyethylene glycol dialysis. the procedure was shown to be inefficient and highly variable, as well as time‐consuming. Direct analysis of aqueous food extracts without a concentration step was found to be possible. With an assay time of 140 min, the ELISA detection limit was 12.5 pg of toxin (corresponding to a sensitivity of 0.5 ngg‐1 of food sample.
Food contamination by diisopropylnaphthalenes from cardboard packages
Authors: STURARO ALBERTO , PARVOLI GIORGIO , RELLA ROCCO , BARDATI SONIA , DORETTI LUCIO
Published: July 2010

A GC/MS investigation performed on two kinds of foods (rice and ‘pasta’) and their packages showed the presence of six diisopropylnaphthalene isomers. It has been demonstrated that such compounds, chemical components of carbonless and thermal copy paper, are present in cardboard, usually obtained with recycled paper. This work also demonstrates that diisopropylnaphthalenes can migrate from boxes to foods.
Electron spin resonance technique identification and dosimetry of irradiated chicken eggs
Authors: ONORI SANDRO , PANTALONI MARCO
Published: July 2010

The electron spin resonance (ESR) technique was tested for the identification and dosimetry of irradiated chicken eggs by ESR measurements of the shell. the spectrum of powdered egg shells was interpreted as the superposition of three signals due to long‐lived CO3, ‐ CO33‐ and CO2‐ ions of the calcium carbonate matrix. Taking the amplitude of the central peak as the dose‐dependent parameter, a linear dose‐effect relationship was obtained up to 10kGy. the results obtained suggest the use of EPR for qualitative and quantitative analysis of irradiated fresh eggs.
Predictive equations for the dielectric properties of foods
Authors: CALAY RAJNISH K. , NEWBOROUGH MARCUS , PROBERT DOUGLAS , CALAY PARGAT S.
Published: July 2010

Variations in the dielectric properties of foods with applied microwave frequencies, and food composition, moisture content and temperature, were investigated. A series of equations to estimate the dielectric properties of a wide range of food materials was deduced from available experimental data and current understanding. the equations are suitable for incorporating into a numerical model to predict the transient temperature and moisture‐content profiles within microwave‐heated foods.
Effect of packaging films on storage stability of intermediate‐moisture deep‐fried mackerel
Authors: MAN YAAKOB B. CHE , BAKAR JAMILAH , MOKRI AHMAD A.K.
Published: July 2010

A storage stability study was conducted on intermediate moisture deep‐fried mackerel packed in polypropylene (PP), high density polyethylene (HDPE) and low density polyethylene (LDPE) for 12 weeks at 27°C. Water activity increased significantly (P < 0.01) during 12 weeks storage from 0.80 to 0.86, 0.88 and 0.91 for PP‐, HDPE‐ and LDPE‐packed samples, respectively. Thiobarbituric acid values increased significantly (P < 0.01) in all packaging films, most rapidly in the LDPE‐packed samples. the physical firmness of the samples decreased similarly and was closely related to the amount of moisture absorbed during storage. Microbial count was low initially but increased most rapidly in LDPE‐packed samples. Sensory evaluation showed that samples packed in PP and HDPE were acceptable for up to 8 weeks storage but for less than 4 weeks in LDPE.
Kinetics of aseptic concentrated orange juice quality changes during commercial processing and storage
Authors: RASSIS DORIT , SAGUY ISRAEL SAM
Published: July 2010

Aseptically concentrated orange juice (COJ) was processed commercially at three holding temperatures (84, 87 and 90°C, 72 s) and stored for up to 7 weeks at 32°C and 15 weeks at 22°C. No differences were found in nonenzymic browning (NEB), vitamin C, sucrose, fructose and glucose, furfural, HMF (5‐hydroxymethyl furfural), and DMHF (2,5‐dimethyl‐4‐hydroxy‐3(2H)‐furanon) concentrations due to the different thermal treatment. the dominating factors affecting vitamin C retention and NEB were time and storage temperature. A lag‐time was observed in NEB formation and its length depended on storage temperature. Furfural concentration was below 1 ppm. HMF reached c. 11 ppm after 7 weeks at 32°C. DMHF concentration decreased throughout the storage period. Sensory evaluation showed a nonsignificant preference for COJ processed at the lower temperature.
Storage characteristics of sous vide cooked roast beef
Authors: HANSEN TINA B. , KNØCHEL SUSANNE , JUNCHER DORTE , BERTELSEN GRETE
Published: July 2010

The technological, microbiological, and sensory storage characteristics of low temperature sous vide cooked roast beef were investigated. the effect of two heat treatments, 59°C (P7010in core 8.4) and 62°C (P7010 in core 15.9) on the stability of spiced roast beef made from Musculus semitendinosus with a high initial microbial load were compared as well as storage temperatures of 2 and 10°C. Although chilling baths with circulating water were used, recommended chilling rates for sous vide products could not be attained. Yield was significantly higher at 59°C and at a storage temperature of 2°C but decreased during storage. At 62°C the meat became significantly more tender than at 59°C as measured by shear force. No differences in microbiology were observed between heating regimes. At low storage temperature products were microbiologically stable over a 35‐day period. At 10°C, however, a rise in psychrotrophic aerobic counts and occasional pack swelling was observed. In a commercial scale experiment conducted with sous vide cooked (62°C) beef with low initial counts, no increase in aerobic counts was observed at 2, 5 and 10°C while swelling occurred in 28% of the packages stored at 10°C and in none at 2 and 5°C. the swelling was due to different types of gas‐producing clostridia. Warmed‐over flavour (as TBARS) showed no development during storage in intact packages, while slicing and serving the roast beef under commercial conditions resulted in a marked increase to < 100 μmole kg−1. In spiced roast beef only minor changes in off‐odour and off‐flavour of the product were observed during 23 days of storage at 2°C.
Postharvest quality and pH of Fusarium inoculated redripe tomatoes stored under controlled atmospheres
Authors: BEAULIEU JOHN C. , SALTVEIT MIKAL E.
Published: July 2010

Tomato (Lycopersicon esculentum Mill. cv. BHN 91) fruit were hand harvested at the pink stage of maturity and stored red‐ripe at 12.5, 20, and 30°C in air, 3% O2+ 5% CO2, and 0.5% O2+ 20% CO2 for up to 16 days. Half the fruit were inoculated with Fusarium solani. Control fruit retained the best appearance in 3% O2+ 5% CO2 at both 20 and 30°C. Inoculated fruit at 12.5, 20 and 30°C in air or 3% O2+ 5% CO2 remained acceptable for approximately 12, 3, and 2 days, respectively, but deteriorated more rapidly than those in 0.5% O2+ 20% CO2 as temperature and time increased. Off‐odours were present in all 0.5% O2+ 5% CO2 treatments by days 12, 9, and 5 at 12.5, 20, and 30°C, respectively. Subjective evaluations tended to remain higher for 0.5% O2+ 20% CO2 even though internal firmness and physical integrity were inferior, and symptoms of anaerobiosis were presumed. A significant time‐ and temperature‐dependent increase in pH of locular and pericarp tissue and supernatant pH occurred in inoculated regions of fruit held in air by day 12, 6 and 3 at 12.5, 20, and 30°C, respectively. In contrast, reduced acidity occurred at 9 and 5 days in 3% O2+ 5% CO2 at 20 and 30°C, respectively. Generally, increased pH followed a trend with air >3% O2+ 5% CO2 < 0.5% O2+ 20% CO2. Titratable acidity in control fruit declined regardless of atmosphere when held at 12.5°C. Initial locule and supernatant pH was sufficiently low to be considered safe, but the pericarp pH of 4.63 approached the food safety threshold, and exceeded 4.7 with storage. Subsequently, food service establishments should beware of potential contamination when holding ripe fruit due to possible decay and metabiosis, anaerobiosis occurring in dressings, and decreased acidity with ripening.
Two‐film theory of flavour release from solids
Authors: HILLS BRYAN P. , HARRISON MARCUS
Published: July 2010

A new theory for flavour release from solid or semi‐solid foods is is proposed which uses twolayer, stagnant film theory to calculate the mass transfer coefficient for the flavour across the food‐saliva interface. The theory is applied to the simple case of flavour release from a boiled sweet. By using the colours which dye the sweet as a substitute for flavour, the theoretical predictions are compared with experiment, both for simple solution of the dye into stirred water and for the more realistic case of mass loss on sucking in the mouth. The role of changing food‐saliva interfacial area is explicitly incorporated into the theory and used as a basis for classifying flavour release from other types of food.
Formulation and rheological characterization of reduced‐calorie food emulsions
Authors: DE CINDIO BRUNO , CACACE DOMENICO
Published: July 2010

Water‐in‐oil‐in‐water (W/O/W) double emulsions are systems where a water‐in‐oil emulsion (W/O) is dispersed in a second aqueous phase. The W/O emulsion exists in the suspending aqueous medium as oil globules containing smaller water droplets.

In this work, a selection of both materials and procedures has been made in order to obtain an optimal formulation of a W/O/W food emulsion for both yield and rheologica] properties.

The rheological properties of W/O/W emulsions have been studied by means of both steady‐shear and oscillatory measurements, and appeared to be similar to those of a simple O/W emulsion having the same volume fraction of dispersed phase, but lower oil content.

This is of great interest to the food industry, since producing double emulsions with the same texture as simple ones, but a lower oil content, helps to formulate reduced‐calorie foods.
Tristimulus colour measurement of rooibos tea extracts as an objective quality parameter
Authors: JOUBERT ELIZABETH
Published: July 2010

Transmission colour measurement of rooibos tea extracts, differing in solid concentration and turbidity, was investigated using cells with a path length of 5, 20 and 30 mm. Inversion of chromaticity parameters occurred with colour measurement of rooibos tea extracts (0.025‐1% solids) using 20 and 30 mm cells. Dilution of extracts decreased the effect of turbidity on the colour parameters, but changed the hue of the extract from red‐brown to yellow. A near linear relationship between the chromaticity parameters and extract concentration was obtained for new expanded a and b scales. Extracts differing by 0.01% in concentration can be correctly ranked visually but not extracts differing by 0.005%. Commercially‐produced tea samples with the highest colour rating by an expert panel had significantly higher a* values than tea with a lower grade indicating the importance of the red tint of rooibos tea extracts in quality evaluation.
Colour and texture changes during sterilization of packed ripe olives
Authors: ROMERO CONCEPCIÓN , GARCÍA PEDRO , BRENES MANUEL , GARRIDO ANTONIO
Published: July 2010

There were no temperature‐ or time‐dependent significant changes in colour or iron content of two cultivars of bottled ripe olives during heat sterilization at temperatures between 117 and 129°C. the addition of calcium had no effect on the activation parameters of texture, although the olives were always firmer when the cation was added. the z‐values for the texture of ripe olives were found to be around 20°C and the average activation energy was 138 kJ/mol.
Modelling the effects of peanut flour, feed moisture content, and extrusion temperature on physical properties of an extruded snack product
Authors: PRINYAWIWATKUL WITOON , BEUCHAT LARRY R. , PHILLIPS R. DIXON , RESURRECCION ANNA V.A.
Published: July 2010

A mixture experimental design was used to evaluate the combined effects of non‐fermented (PDPF) and fermented (F‐PDPF) peanut flours, added feed moisture content, and extrusion temperature on physical properties of extruded cornstarch‐peanut flour‐based snacks. Moisture content, expansion ratio, bulk density, modified Kramer compression‐shear force and colour of extrudates were significantly affected by the amount of PDPF and F‐PDPF in the formulation. Oil absorption by extrudates was only influenced by the type of peanut flour. Within the range of (per 1‐kg batch) 0.30–0.34 g g−1added water, 0.16–0.20 g g−1PDPF and/or F‐PDPF, and extrusion temperatures of 125 to 150°C, extrudates with a wide range of functional characteristics can be produced.
Water vapour permeability of edible bilayer films of wheat gluten and lipids
Authors: GONTARD NATHALIE , MARCHESSEAU SYLVIE , CUQ JEAN‐LOUIS , GUILBERT STEPHANE
Published: July 2010

Various formulations and methods of fabricating edible bilayer films consisting of wheat gluten as a structural layer and a thin lipid layer as a moisture barrier were investigated and examined for water vapour permeability. Solid lipids such as beeswax or paraffin wax deposited in a molten state onto the base film were the most effective water vapour barriers. A film consisting of wheat gluten, glycerol and diacetyl tartaric ester of monoglyceride as one layer, and beeswax as the other yielded a water vapour permeability of 0.0048 g mm m−2 mmHg−1 24h−1, which was less than that obtained with low density polyethylene.
Using generalized autoregressive error models to understand fire–vegetation–soil feedbacks in a mulga–spinifex landscape mosaic
Authors: Murphy Brett P. , Paron Paolo , Prior Lynda D. , Boggs Guy S. , Franklin Donald C. , Bowman David M. J. S.
Published: July 2010

Aim To develop a new modelling approach for spatially autocorrelated non‐normal data, and apply it to a case study of the role that fire–vegetation–soil feedbacks play in maintaining boundaries between fire‐sensitive and fire‐promoted plant communities.

Location A mulga (Acacia aneura) shrubland–spinifex (Triodiaspp.) grassland mosaic, central Australia.

Methods Autoregressive error models were extended to non‐normal data by incorporating neighbourhood values of the response and predictor variables into generalized nonlinear models. These models were used to examine the environmental correlates of three response variables: mulga cover; fire frequency in areas free of mulga; and the presence of mulga banding. Mulga cover and mulga banding were assessed visually by overlaying 4477 × 1 km2grid cells on both Landsat 7 ETM+ and very high resolution imagery. Fire frequency was estimated from an existing fire history for central Australia, based on remotely sensed fire scars.

Results The autoregressive error models explained 27%, 47% and 57% of the null deviance of mulga cover, fire frequency and mulga banding, respectively, with 12%, 15% and 24% of the null deviance being explained by environmental variables alone. These models accounted for virtually all residual spatial autocorrelation. While there was a clear negative relationship between mulga cover and fire frequency, there was little evidence that mulga was being restricted to parts of the landscape with inherently low fire frequencies. Mulga was most abundant at very low slope angles and on red earths, both of which are likely to reflect high site productivity, while fire frequency was not clearly affected by slope angle and was also relatively high on red earths.

Main conclusions The modelling approach we have developed provides a much needed way of analysing spatially autocorrelated non‐normal data and can be easily incorporated into an information‐theoretic modelling framework. Using this approach, we provide evidence that mulga and spinifex have a highly antagonistic relationship. In more productive parts of the landscape, mulga suppresses spinifex and fire, while in less productive parts of the landscape, fire and spinifex suppress mulga, leading to the remarkable abruptness of mulga–spinifex boundaries that are maintained via fire–vegetation–soil feedbacks.
California annual grass invaders: the drivers or passengers of change?
Authors: HilleRisLambers Janneke , Yelenik Stephanie G. , Colman Benjamin P. , Levine Jonathan M.
Published: July 2010

1. The dominance of invasive species is often assumed to reflect their competitive superiority over displaced native species. However, invasive species may be abundant because of their greater tolerance to anthropogenic impacts accompanying their introduction. Thus, invasive species can either be the drivers or passengers of change.

2. We distinguish between these two possibilities in California grasslands currently dominated by Mediterranean annuals (exotics) and subjected to livestock grazing since European settlement. We focused on native annual grasses and forbs, an understudied species‐rich component of the California flora, and Mediterranean annual grasses, currently dominant and among the first non‐native plants introduced to the area.

3. We established a field experiment with fenced and unfenced blocks in a cattle pasture. We measured concentrations of limiting resources (nitrogen, phosphorus, light and soil moisture) in monoculture plots as an index of competitive ability (i.e. R*). We then quantified grazing impacts on biomass and seed production in grazed vs. ungrazed monoculture plots. Finally, we measured biomass and seed production of each species competing in mixture plots, in the presence and absence of grazers.

4. We found that native and exotic species did not differ in R* indices of competitive ability, i.e. concentrations of limiting resources in ungrazed native monoculture plots did not differ from concentrations in ungrazed exotic monoculture plots. By contrast, exotic annuals suffered less from grazing than native annuals, perhaps reflecting their longer evolutionary history with cattle grazing. Consistent with these results, native and exotic annuals were equally abundant in ungrazed mixtures, but exotic species overwhelmingly dominated grazed mixtures.

5. Species able to draw down nitrogen and light to lower levels in monocultures (i.e. those with lower R* values) dominated biomass and seeds in mixed plots without grazers. However, R* did not predict the relative abundance of species in grazed plots. Moreover, the relative abundance of species in mixtures did not correlate with grazing impacts on their monocultures, implying that grazing alters inter‐specific competitive dynamics.

6. Synthesis. We demonstrate that the displacement of native annuals by Mediterranean annual grasses in California may largely have been driven by cattle grazing.
Biological characterization of French Potato virus Y (PVY) isolates collected from PVY‐susceptible or ‐resistant tobacco plants possessing the recessive resistance gene va
Authors: Lacroix C. , Glais L. , Kerlan C. , Verrier J.‐L. , Jacquot E.
Published: July 2010

Improved tobacco cultivars introgressed with alleles of the recessive resistance va gene have been widely deployed in France to limit agronomical consequences associated with Potato virus Y (PVY) infections. Unfortunately, necrotic symptoms associated with PVY have been reported on these cultivars suggesting that PVY is able to overcome the resistance. A field survey was performed in France in 2007 to (i) estimate the prevalence of PVY in tobacco plants showing symptoms and (ii) characterize PVY isolates present in susceptible and va‐derived tobacco cultivars. A serological typing procedure, applied to 556 leaves collected from different French tobacco growing areas, was performed using polyclonal antisera raised against different viral species including PVY. Viral species were detected in 80·8% of leaves and PVY was present in 83·5% of infected samples. However, statistical analysis confirmed that the probability of a tobacco plant being infected with PVY is reduced in va hosts. Eighty‐six PVY isolates were mechanically inoculated on one susceptible and three va‐derived tobacco cultivars used as indicator hosts to define virulence of these isolates against alleles 0, 1 and 2 of the va gene. Both qualitative and quantitative analyses showed that 55 PVY isolates were able to overcome the three va alleles. Moreover, the monitored biological diversity of PVY isolates was higher in the susceptible tobacco hosts than in the va‐derived ones. This study helps to understand consequences of the deployment of the va gene in tobacco on diversity and virulence of PVY isolates.
Neuroendocrine and Genetic Control of Seasonal Reproduction in Sheep and Goats
Authors: Chemineau P , Bodin L , Migaud M , Thiéry JC , Malpaux B
Published: July 2010

Contents

Goats and sheep generally express seasonal variations in their sexual behaviour, spermatogenic activity (from moderate decrease to very low sperm production), gamete quality (variations in fertilization rates and embryo survival), ovulation frequency (presence or absence of ovulation), and ovulation rate (number of eggs shed per ovulation period). This induces seasonal availability of derived, fresh animal products (meat, milk and cheese) because of a more or less marked seasonal distribution of births. A complex combination of an endogenous circannual rhythm driven and synchronized by light and melatonin, which controls the pulsatile activity of GnRH neurons in the preoptic‐mediobasal hypothalamus, is responsible for these changes. Dramatic and long‐term neuroendocrine changes, involving different neuromediator systems and neuronal plasticity, have been shown to play a role in these processes. A strong variability between breeds exists in both species regarding the dates of onset and end of the breeding season, with a gradient of seasonality from southern to northern latitudes. Within a breed, seasonal traits are heritable; thus, genetic selection could be one way to decrease seasonality in sheep and goats in the future.
Activation of Tolloid‐like 1 gene expression by the cardiac specific homeobox gene Nkx2–5
Authors: Sabirzhanova Inna , Sabirzhanov Boris , Bjordahl Joy , Brandt Jessica , Jay Patrick Y. , Clark Timothy G.
Published: July 2010

Mammalian Tolloid‐like 1 (Tll‐1) is a pleiotropic metalloprotease that is expressed by a small subset of cells within the precardiac mesoderm and is necessary for proper heart development. Following heart tube formation Tll‐1 is expressed by the endocardium and regions of myocardium overlying the region of the muscular interventricular septum. Mutations in Tll‐1 lead to embryonic lethality due to cardiac defects. We demonstrate that the Tll‐1 promoter contains Nkx2–5 binding sites and that the Tll‐1 promoter is activated by and directly binds Nkx2–5. Tll‐1 expression is ablated by a dominant negative Nkx2–5 or by mutation of the Nkx2–5 binding sites within the Tll‐1 promoter. In vivo, Tll‐1 expression is decreased in the hearts of Nkx2–5 knockout embryos when compared with hemizygous and wild‐type embryos. These results show that Nkx2–5 is a direct activator of Tll‐1 expression and provide insight into the mechanism of the defects found in both the Tll‐1 and Nkx2–5 knockout mice.
R1 version, self‐concept in Taiwanese adolescents with congenital heart disease
Authors: Chen Chi‐Wen , Chen Yueh‐Chih , Beckstead Jason W. , Kennel Susan , Evans Mary E.
Published: July 2010

Background:  The objectives of this study were to evaluate and compare differences in self‐concept between male and female adolescents with congenital heart disease, and to compare the self‐concepts of these adolescents to that of the general adolescent population using normative data.

Methods:  A total of 300 adolescents, 143 male and 157 female, from two medical centers in Taiwan completed the Tennessee Self‐Concept Scales and the scores of male and female subjects were compared. The scores of adolescents with congenital heart disease were also compared with normative data of healthy Taiwanese adolescents.

Results:  Girls with congenital heart disease showed significantly lower mean scores in Physical Self, Social Self, Personal Self, Academic Self and Overall Self domains on the Tennessee Self‐Concept Scales when compared to boys with congenital heart disease. When compared to the average value of normative data, adolescent boys with congenital heart disease had significantly higher mean T‐scores on Physical Self, Family Self, Social Self, Personal Self, Academic Self and Overall Self, and adolescent girls had significantly higher mean T‐scores in Moral‐ethical Self, Social Self, Personal Self, Academic Self and Overall Self domains. There were weak negative correlations between severity of congenital heart disease and Physical Self T‐scores, and between the number of heart operations and Academic T‐scores.

Conclusions:  Self‐concept in adolescents with congenital heart disease is similar to or even higher than that of their normal counterparts. More holistic views of adolescents with congenital heart disease, including their self‐concept, appear warranted, especially for adolescent girls with congenital heart disease.
High prevalence of moderately severe vitamin D deficiency in preterm infants
Authors: Dawodu Adekunle , Nath Ravi
Published: July 2010

Background: The recommended dose of vitamin D supplementation of preterm infants is based on data from populations in which severe vitamin D deficiency is uncommon and may be inadequate for infants in high risk population. However, data on vitamin D status of preterm infants in high‐risk populations, such as Middle Eastern countries is scarce.

Methods: This study investigates the vitamin D status of Arab mothers and their preterm infants. Maternal serum and cord blood 25(OH)D, calcium (Ca), phosphorus (P) and alkaline phosphate (ALP) were measured at delivery. Serum 25(OH)D was measured by HPLC while the other biochemical parameters were measured by standard autoanalyzer.

Results: Thirty‐four preterm infants were studied. The mean gestational age was 31.4 weeks and birth weight was 1667 g. The median serum 25(OH)D of 17.0 nmol/L in 28 mothers and 14.5 nmol/L in 34 cord blood samples were low. The median maternal and cord blood Ca, P and ALP levels were within normal range. Fifteen (44%) of the infants had moderately severe vitamin D deficiency (serum 25 (OH)D levels <12.5 nmol/L). The median serum 25(OH)D levels of mothers who had reportedly taken prenatal vitamin D supplementation and those who had not were similar (17.3 vs 16.3) nmol/L. The mean serum 25(OH)D levels among preterm infants in this study were low when compared to levels in Caucasians preterm infants on which the current vitamin D recommendations are based.

Conclusion: The high prevalence of moderately severe vitamin D deficiency in Arab preterm infants provides a justification to investigate vitamin D requirement of preterm infants in this and other high‐risk populations.
Learner‐Generated Noticing of Written L2 Input: What Do Learners Notice and Why?
Authors: Park Eun Sung
Published: July 2010

This study explored learners’ self‐generated noticing of L2 input. It is motivated by previous research on input enhancement which suggested that learners are able to notice certain aspects of input on their own without any external means to direct their attention. Drawing on insights that learner‐generated noticing is largely mediated by learner‐internal factors, this study specifically traced the effects of learners’ first language (L1), and their current second language (L2) knowledge in generating noticing. Two L1 groups (Japanese and English) with no knowledge of the L2 (Korean) were exposed to written L2 input and probed for their noticing behavior under a “zero knowledge” condition, and a “some knowledge” condition (i.e., after they had been taught some L2 words). Results revealed that under the “zero knowledge” condition, both groups exhibited similar noticing patterns prompted by perceptual input properties. Under the “some knowledge” condition, however, the Japanese group seemed to have noticed more input items and processed them at a deeper level of understanding. Insights gleaned from the study are discussed with avenues for future research.
PRACTITIONERS CORNER: Tests for Cointegration in Models with Regime and Trend Shifts
Authors: Gregory Allan W. , Hansen Bruce E.
Published: July 2010

ABSTRACT

Recently Gregory and Hansen (1996) proposed a number of residual‐based tests for cointegration in models with the possibility of a structural break. They considered three models: (i) level shift; (ii) level shift with trend; and (iii) regime shift (both level shift and slope coefficients can change). We introduce a more general model that permits a trend shift as well as a regime shift and we provide the critical values appropriate for testing this hypothesis.
Biomarkers and endogenous determinants of dofetilide‐induced torsades de pointes in α1‐adrenoceptor‐stimulated, anaesthetized rabbits
Authors: Farkas Attila S. , Rudas László , Makra Péter , Csík Norbert , Leprán István , Forster Tamás , Csanády Miklós , Papp Julius Gy. , Varró András , Farkas András
Published: July 2010

BACKGROUND AND PURPOSE

Torsades de pointes (TdP) liability is a stochastic event, which indicates that unidentified factors have an important role in facilitating the initiation of TdP by increasing the probability of TdP occurrence. We sought to identify factors that facilitate drug‐induced TdP.

EXPERIMENTAL APPROACH

We studied dofetilide‐induced TdP in pentobarbital‐anaesthetized, phenylephrine‐sensitized rabbits, seeking biomarkers that discriminated between the animals that experienced TdP (‘TdP+’ animals) and those that did not (‘TdP−’ animals). As novel variables, the beat‐to‐beat variability and instability of ECG intervals were measured at preset times, irrespective of whether or not hearts were in stable sinus rhythm (‘absolute’ variability and instability). Autonomic activity was also determined.

KEY RESULTS

Dofetilide delayed repolarization and induced arrhythmias prior to TdP. The variability of the coupling interval and shape of arrhythmic beats before TdP were significantly greater in the ‘TdP+’ group than in the ‘TdP−’ group. Accordingly, the ‘absolute’ variability and instability of the ECG intervals were significantly elevated in the ‘TdP+’ group. Phenylephrine increased significantly the up‐baroreflex sensitivity in the ‘TdP+’ group before dofetilide administration.

CONCLUSIONS AND IMPLICATIONS

‘Preceding’ arrhythmias have characteristics that permit prediction of TdP occurrence: the more chaotic the ventricular rhythm, the greater the probability of TdP initiation. This suggests that complexity of the arrhythmic beats may play an important mechanistic role in TdP genesis. The electrical instability quantified by the novel ‘absolute’ variability and instability parameters correlates with the probability of TdP occurrence. Baroreflex may contribute to TdP genesisin vivo.
Covariates of Craving in Actively Drinking Alcoholics
Authors: Chakravorty Subhajit , Kuna Samuel T. , Zaharakis Nikola , O’Brien Charles P. , Kampman Kyle M. , Oslin David
Published: July 2010

The goal of this cross‐sectional study was to assess the relationship of alcohol craving with biopsychosocial and addiction factors that are clinically pertinent to alcoholism treatment. Alcohol craving was assessed in 315 treatment‐seeking, alcohol dependent subjects using the Penn Alcohol Craving Scale questionnaire. Standard validated questionnaires were used to evaluate a variety of biological, addiction, psychological, psychiatric, and social factors. Individual covariates of craving included age, race, problematic consequences of drinking, heavy drinking, motivation for change, mood disturbance, sleep problems, and social supports. In a multivariate analysis (R2= .34), alcohol craving was positively associated with mood disturbance, heavy drinking, readiness for change, and negatively associated with age. The results from this study suggest that alcohol craving is a complex phenomenon influenced by multiple factors. (Am J Addict 2010;00:1–8)
Applying the Transtheoretical Model to the Readiness to Change Blood‐Borne Virus Transmission Behaviors among Drug‐Dependent Inmates
Authors: Ko Nai‐Ying , Yen Cheng‐Fang , Chen Cheng‐Hui , Lee Hsin‐Chun , Ko Wen‐Chien , Lin Hsi‐Hsun , Hsu Su‐Ting
Published: July 2010

Our study set out to assess readiness to change blood‐borne virus transmission behaviors using the Transtheoretical Model among inmates in a court‐ordered detention center. A cross‐sectional descriptive study was conducted in southern Taiwan. All men convicted of illicit drug use and sentenced to undergo the 6‐month detoxification program were invited to participate. Half of the 172 participating inmates described themselves as being in the contemplation stage of change. The length of residency in the detoxification program was not associated with self‐reported readiness to change, χ2= 6.53, p = .16. Inmates in the precontemplation stage had increased rates for high‐risk behaviors than those in the contemplation and action stages (p < .001). The efficacy of forced‐abstinence detention programs on readiness to change risky behaviors needs to be reevaluated. (Am J Addict 2010;00:1–7)
Obesity, Smoking, and Frontal Brain Dysfunction
Authors: Bauer Lance , Dick Danielle , Bierut Laura , Bucholz Kathleen , Edenberg Howard , Kuperman Samuel , Kramer John , Nurnberger John , O’Connor Sean , Rice John , Rohrbaugh John , Schuckit Marc , Tischfield Jay , Porjesz Bernice , Hesselbrock Victor
Published: July 2010

Obesity, smoking, and conduct problems have all been associated with decrements in brain function. However, their additive and interactive effects have rarely been examined. To address the deficiency, we studied P300a and P300b electroencephalographic potentials in 218 women grouped by the presence versus absence of: (1) a BMI ≥ 30 kg/m2; (2) recent smoking; and (3) ≥ 2 childhood conduct problems. Analyses revealed smaller P300a and P300b amplitudes over the posterior scalp among recent smokers versus nonsmokers. No corresponding group differences were found in P300 latencies or frontal scalp amplitudes. The most interesting analysis result was an interaction between conduct problems and obesity limited to the frontally generated P300a component: its latency was significantly greater in women with both attributes than in those with either or neither attribute. An exploratory ANOVA, substituting the genotype of a GABRA2 SNP for conduct problems, also demonstrated an interaction with obesity affecting P300a latency. It is hypothesized that conduct problems, and a conduct‐problem‐associated GABRA2 genotype, decrease the age‐of‐onset and/or increase the lifetime duration of obesity. As a result, they may potentiate the adverse effects of obesity on frontal white matter and thereby increase P300a latency. Smoking may affect brain function by a different mechanism to reduce posterior scalp P300a and P300b amplitudes while preserving frontal scalp P300a latency and amplitude. (Am J Addict 2010;00:1–10)
A Randomized Trial of Oral Naltrexone for Treating Opioid‐Dependent Offenders
Authors: Coviello Donna M. , Cornish James W. , Lynch Kevin G. , Alterman Arthur I. , O’Brien Charles P.
Published: July 2010

Offenders with a history of opioid dependence are a particularly difficult group to treat. A large proportion of offenders typically relapse shortly after release from prison, commit drug‐related crimes, and then are arrested and eventually re‐incarcerated. Previous research demonstrated that oral naltrexone was effective in reducing opioid use and preventing recidivism among offenders under federal supervision. The 111 opioid‐dependent offenders in this study were under various levels of supervision that included county and federal probation/parole, a treatment court, an alternative disposition program, and an intermediate punishment program. Subjects were randomly assigned to receive 6 months of either 300 mg per week of oral naltrexone plus standard psychosocial treatment as usual (n = 56) or standard psychosocial treatment as usual (TAU) without naltrexone (n = 55). While the TAU subjects who remained in treatment used more opioids than the naltrexone subjects who remained, the high dropout rate for both groups made it difficult to assess the effectiveness of naltrexone. The study provides limited support for the use of oral naltrexone for offenders who are not closely monitored by the criminal justice system. (Am J Addict 2010;00:1–11)
Evolution of craniofacial novelty in parrots through developmental modularity and heterochrony
Authors: Tokita Masayoshi , Kiyoshi Takuya , Armstrong Kyle N.
Published: July 2010

SUMMARYParrots (order Psittaciformes) have developed novel cranial morphology. At the same time, they show considerable morphological diversity in the cranial musculoskeletal system, which includes two novel structures: the suborbital arch and the musculus (M.) pseudomasseter. To understand comprehensively the evolutionary pattern and process of novel cranial morphology in parrots, phylogenetic and developmental studies were conducted. Firstly, we undertook phylogenetic analyses based on mitochondrial ribosomal RNA gene sequences to obtain a robust phylogeny among parrots, and secondly we surveyed the cranial morphology of parrots extensively to add new information on the character states. Character mapping onto molecular phylogenies indicated strongly the repeated evolution of both the suborbital arch and the well‐developed M. pseudomasseter within parrots. These results also suggested that the direction of evolutionary change is not always identical in the two characters, implying that these characters are relatively independent or decoupled structures behaving as separate modules. Finally, we compared the developmental pattern of jaw muscles among bird species and found a difference in the timing of M. pseudomasseter differentiation between the cockatielNymphicus hollandicus(representative of a well‐developed condition) and the peach‐faced lovebirdAgapornis roseicollis(representative of an underdeveloped condition). On the basis of this study, we suggest that in the development of novel traits, modularity and heterochrony facilitate the diversification of parrot cranial morphology.