bluuebunny/crossref_metadata_2025_split huggingface dataset:
Exposure of arthropod predators to Cry1Ab toxin in Bt maize fields
Authors: Obrist L. B. , Dutton A. , Albajes R. , Bigler F. 
Published: April 2006

Abstract.  1. To assess the risks of an insect‐resistant transgenic plant for non‐target arthropods, it is important to investigate the exposure of non‐target species to the transgene product. Exposure of predators in the field depends on the toxin levels in food sources, their feeding ecology and that of their prey.2. To verify the transmission of Cry1Ab toxin through the food chain, and thus exposure of predators in the field, samples from different plant tissues, herbivores, and predators in Bt maize fields in Spain (Event 176) were collected at different periods over the season and the toxin content was measured using ELISA. Complementary laboratory studies were performed with the omnivorous predator Orius majusculus to assess the toxin uptake and persistence after feeding on variable Bt‐containing food sources.3. Field results revealed that toxin content in some herbivores was negligible (aphids, thrips, leafhoppers) compared with those in spider mites. The latter herbivore only occurred after pollen shed and contained three times greater toxin levels than Bt maize leaves.4. Data confirmed that the Bt toxin can be transferred to predators, that is to say to Orius spp., Chrysoperla spp., and Stethorus sp. This only applied when Bt maize pollen or spider mites were available. The passage of Bt toxin to O. majusculus via these two food sources was also confirmed in the laboratory. Contrastingly, some predators in the field (hemerobiids, Nabis sp., Hippodamia sp., Demetrias sp.) contained no or negligible toxin levels even when pollen or spider mites were present.5. Besides essential information for exposure assessment of numerous arthropod predators, this study provides an insight into the feeding ecology of different arthropods in the maize system.
Melanism in a larval Lepidoptera: repeatability and heritability of a dynamic trait
Authors: Lee Kwang Pum , Wilson Kenneth 
Published: April 2006

Abstract. 1. Although it is well established that the deposition of melanin pigment in the cuticle of larval Lepidoptera is influenced by both environmental and genetic factors, few studies have examined intra‐individual regional variation in the degree of melanism or the ontogenetic dynamics of this trait. Here, heritable and density‐dependent effects on within‐individual and stage‐specific variation in melanism were examined in caterpillars of the Egyptian cotton leafworm,Spodoptera littoralis(Boisduval).2. Using quantitative spectrometric methods, it is shown that cuticular melanism changes dramatically within larval stadia, showing the highest and lowest levels of melanism early (first day) and late (final day) in each larval stadium respectively. However, solitary‐reared caterpillars were significantly paler than those reared gregariously at all stages of development and maintained greater levels of variation in melanism. This variation in melanism was repeatable and exhibited a significant heritable component (narrow sense heritability based on offspring–parent regressions:h2 = 0.18–0.30).3. The degree of melanism was correlated negatively with larval body weight in solitary caterpillars, but not gregarious ones. Melanism also varied spatially, with the lateral longitudinal band being consistently darker than the dorsal or dorso‐lateral bands. Crowd‐rearing increased melanism in all regions of larval cuticle, but the extent of crowding‐induced melanism was more pronounced in the dorsal and dorso‐lateral bands than in the lateral one.4. These results indicate that although cuticular melanism is a highly dynamic trait, ontogenetic changes in relative cuticular melanism are both predictable and repeatable within individuals and genotypes. This has implications for our understanding of the evolution of melanism and for applying artificial selection on the basis of colour.
The spatial pattern of vegetation in cut and grazed grass/white clover pastures
Authors: EDWARDS G. R. , PARSONS A. J. , NEWMAN J. A. , WRIGHT I. A. 
Published: April 2006

AbstractThe spatial patterns of white clover and sward surface height (SSH) that developed In established perennial ryegrass (Lolium perenne)/white clover (Trifolium repens) pastures undercutting lent every 4 weeks to 5 cm) and gracing (continuously grazed with sheep to 5 cm) were measured. While clover cover was recorded in 1000 contiguous 5 × 5‐cm quadrats down 50‐m permanent transects from early spring to late autumn. Measurements of SSH were made at 10‐cm intervals down the same transect. Spatial pattern was analysed using two‐term local quadrat variance and patch‐gap analysis. At least two scales of spatial pattern existed for white clover when defoliation treatments began. White clover was not distributed at random but found in patches (mean size = 1.1 m) where it was finely intermixed with grass. Patches, separated by gaps (regions of no clover) (mean size = 2.3 m), were in turn aggregated into ‘patches of patches’, separated by larger gaps (mean size = 4.1 m). Under grazing the pattern of patches and gaps did not alter. Under cutting, patch size increased and gap size decreased, explaining in part the greater mass and cover of white clover that arose in cut than grazed swards during the experiment. No new patches of white clover due to seedling establishment or clonal growth were observed in either cut or grazed swards. The intensity of pattern increased in both cut and grazed swards, but the increase was greater m cut swards. The initial single scale of spatial pattern of SSH of tall patches (mean size = 1.2 m) separated by short patches (mean size = 2.7 m) did not change under grazing. SSH became uniform under cutting. It is suggested that the response of plants to selective (spatially heterogeneous) grazing is a crucial factor in the development and maintenance of spatial pattern in grasslands. The importance of spatial pattern to our understanding and interpretation of plant‐plant and plant‐animal interactions and to the composition of temperate grasslands is considered.
Effects of inoculant treatment on ryegrass silage fermentation, digestibility, rumen fementation, intake and performance of lactating dairy cattle
Authors: KEADY T. W. J. , MURPHY J. J. 
Published: April 2006

AbstractA randomized block experiment involving thirty‐six lactating dairy cattle was carried out to evaluate a bacterial inoculant (Grazyme Grobac, Agritech), containing bacteria, enzymes and a rumen enhancer, as a silage additive. Herbage from the primary regrowth of predominantly perennial ryegrass swards was ensiled unwilted and precision‐chopped after a 51‐d growth interval on 4 and 5 August. Alternate loads of herbage were ensiled either untreated (C) or treated with formic acid at a rate of 2.65 1 (t herbage)−1 (F) or the inoculant at a rate of 0.64 kg (t grass)−1 (I). The treatments were harvested using the same harvester in the rotation of I, F and C treatments. Mean dry‐matter (DM), water‐soluble carbohydrate and nitrate nitrogen (N) concentrations and buffering capacity of the C herbages at ensiling were 198 g kg−1, 18 2 g kg−1, 290 mg (1 juice)−1 and 379 mequiv. (kg DM)−1 respectively. For silages C, F and I pH values were 3.7, 3.8 and 3.8 and ammonia N concentrations 61, 43 and 58 g (kg total N)−1 respectively. Inoculant treatment did not alter aerobic stability of the silages, whereas formic acid treatment increased it. The silages were offered ad libitum and supplemented with 5 kg of concentrates per head daily. For treatments C, F and I silage DM intakes were 10.8, 11.2 and 10.8 (s.e. 0–33) kg d−1, milk yields 21.3, 20.9 and 20.7 (s.e. 0.52) kg d−1, fat concentrations 38.3, 40.3 and 37.2 (s.e. 0.83) g kg−1 and protein concentrations 30.8, 32.6 and 32.6 (s.e. 0.49) g kg−1 respectively. Inoculant treatment did not alter (P0.05) the digestibility coefficients of the total diets, whereas formic acid treatment decreased DM (P0.05), organic matter (P0.05), neutral detergent fibre (P0.01) and hemicellulose (P0.01) digestibilities. Formic acid treatment altered rumen fermentation patterns, whereas inoculant treatment had no effect. It is concluded that, relative to a well‐preserved untreated silage, additive treatment did not alter DM intake, milk yield or fat plus protein yield. However, both additive treatments increased milk protein concentrations and formic acid treatment increased milk fat concentration relative to the well‐preserved, untreated silage.
Nitrogen uptake by grasses: changes induced by competing neighbour plants differing in frequency of defoliation
Authors: THORNTON B. , MILLARD P. 
Published: April 2006

AbstractNitrogen uptake can be modified by both frequency of defoliation and competing neighbour plants. The objective of this study was to investigate nitrogen uptake by Lolium perenne and Festuca rubra subject to weekly or monthly defoliation with five neighbours: either none, L perenne clipped weekly, L. perenne clipped monthly, F. rubra clipped weekly or F. rubra clipped monthly. Plants were grown in sand culture with nutrients supplied as solutions. Nitrogen uptake over a I‐week period commencing at the time of a defoliation event was estimated using l5N as a tracer. L. perenne had greater dry weight and nitrogen uptake than F. rubra. Neighbours reduced nitrogen uptake per plant. When neighbours were present, clipping them more frequently resulted in greater uptake by sample plants. Over 57% of total plant uptake was partitioned towards the two youngest leaves. In mixtures of L. perenne with F. rubra, the percentages of the total pot dry weight and N content recovered in sample L. perenne plants increased when they were clipped less frequently, compared with when the accompanying F. rubra plants were clipped less frequently.
The conservation management of mesotrophic (meadow) grassland in Northern England. 2. Effects of grazing, cutting date, fertilizer and seed application on the vegetation of an agriculturally improved sward
Authors: SMITH R. S. , CORKHIL P. , SHIEL R. S. , MILLWARD D. 
Published: April 2006

The plant species number and composition, iind yield of herbage biomass of an agriculturally improved hay meadow were assessed after 4 years under various combinations of grazing, fertilizer applicution. cutting date and seed addition treatments in a replicated split‐plot design.Grazing treatments consisted of either autumn grazing with cattle and sheep, spring grazing with sheep or both regimes. Fertilizer application treatments consisted of either 25 kg ha−1 N plus 12–5 kg ha−1 P and K or no fertilizer. Cutting date treatments consisted of cuts on either 14 June, 2i July or 1 September. Seed addition treatments consisted of either no addition or sowing with a range of meadow species in the autumn. Data analysis was by correspondence analysis and analysis of variance.Species number decreased with fenilizer use and when the cutting date was 1 September. A range of species was affected by the main treatments and there were some first‐order interactions, mainly between cutting date and fertilizer application. Rhinanthus minor was particularly favoured by the seed addition treatment. Species attnbutes in the regenerative and established phase were related to treatments and their effect on species composition.The National Vegetation Classification communities were associated with particular treatment regimes. The 21 July cutting date favoured ‘improved’ over ‘unimproved‐traditional’ swards, with spring grazing favouring ‘unimproved‐traditional’ swards.Lowest yields of herbage biomass were associated with autumn and spring grazing, the 14 June cutting date and no fenilizer treatments. The fenil‐izer, 1 September cutting date and auiumn grazing treatments gave the highest yields.The implications of these results are discussed in terms of the conservation management required to return agriculturally improved mesotrophic grassland to a species composition similarto that of traditionally managed grassland.
When log‐dwellers meet loggers: impacts of forest fragmentation on two endemic log‐dwelling beetles in southeastern Australia
Authors: SCHMUKI C. , VORBURGER C. , RUNCIMAN D. , MACEACHERN S. , SUNNUCKS P. 
Published: April 2006

AbstractAnthropogenic activities continue to cause massive fragmentation and reduction of forest area worldwide. With fragmentation and reduction of habitat recognized as the greatest threats to biodiversity, the implementation of improved, informed and conservation‐based forestry practices is essential, and requires a greater understanding of the responses of different organisms to forest fragmentation. While genetic techniques can add invaluable insights to fragmentation studies they have rarely been employed, particularly for multiple species. In the present study, we combined genetic information, obtained from allozyme loci and anonymous single copy nuclear DNA markers, with ecological data to investigate the impacts of forest fragmentation on two log‐dwelling beetles with different life histories, in an ‘islands of bush in a sea of pine’ model, at Tumut in New South Wales, Australia. Both the relatively mobile (i.e. has high dispersal ability and/or broad habitat range) Adelium calosomoides and the less mobile Apasis puncticeps showed reduced mobility and gene flow in fragmented compared to continuous forest: there was significantly greater isolation by distance and stronger local structure revealed by spatial autocorrelation in fragmented forest. Analysis of patch and species characteristics revealed that genetic and demographic structure may be influenced by log degradation class for both species, and number of potential dispersal barriers, distance from continuous forest and desiccation intolerance/moisture preference for Ap. puncticeps. Thus the pine plantation matrix poses a barrier or filter for gene flow and mobility in both beetle species.
The ruddy duckOxyura jamaicensisin Europe: natural colonization or human introduction?
Authors: MUÑOZ‐FUENTES VIOLETA , GREEN ANDY J. , SORENSON MICHAEL D. , NEGRO JUAN J. , VILÀ CARLES 
Published: April 2006

AbstractNative to North America, ruddy ducksOxyura jamaicensisnow occur in 21 countries in the western Palaearctic (including Iceland) and their expanding population threatens the native white‐headed duck,Oxyura leucocephala, through hybridization and possibly competition for food and nest sites. We used mitochondrial DNA sequences and nuclear microsatellites to test whether the European ruddy duck population is descended solely from the captive population in the UK, which traces to seven individuals imported from the USA in 1948, or, alternatively, has been augmented by natural dispersal of birds from North America. Limited genetic diversity in the European population is consistent with a founder population as small as seven birds. In addition, shifts in allele frequencies at several loci, presumably due to genetic drift in the founding population, result in significant differentiation between the European and North American populations. Despite the recent separation of these populations, almost all individuals could be unambiguously assigned based on their composite genotypes, to one of two distinct populations, one comprising all of the European ruddy ducks we sampled (including those from Iceland and captive birds in the UK) and the other comprising all North American samples. Our results confirm that the European ruddy duck population is likely to derive solely from the captive population in the UK and we find no evidence of recent arrivals from North America or of admixture between ruddy ducks from Europe and North America.
Presence of Sunflower Downy Mildew in an Integrated Weed Control Field Trial
Authors: Covarelli L. , Tosi L. 
Published: April 2006

AbstractSurveys were carried out during May–June 2004 to investigate the presence of sunflower plants (cv. Sanbro) showing systemic downy mildew infections in an experimental field located in central Italy (Umbria) where chemical and mechanical weed control measures were being compared. Race characterization of Plasmopara helianthi isolates, using the triplet coding system, resulted in race 703. Furthermore, greenhouse and laboratory experiments on the sensitivity of pathogen isolates to metalaxyl revealed an insufficient seed dressing of the commercial hybrid compared with the registered rate and a decreased sensitivity of P. helianthi isolates to metalaxyl. Besides, an increase of the disease incidence following some mechanical weed control measures was also noted. Plasmopara helianthi attacks could probably be attributed to agronomic (short crop rotation), phytosanitary (insufficient seed dressing) and genetic (lack of resistance genes) factors influenced by favourable climatic conditions.
Comparison of Screening Methods for Resistance to Fusarium Root Rot in Common Beans (Phaseolus vulgaris L.)
Authors: Chaudhary S. , Anderson T. R. , Park S. J. , Yu K. 
Published: April 2006

AbstractRoot rot, caused by Fusarium solani f. sp. phaseoli, is one of the main root diseases impacting production of common beans throughout the world. Because resistance of common beans to root rot is a quantitative trait that is strongly influenced by environmental factors, reproducible methods to screen bean plants for resistance to root rot are critical to the selection process. In this study, we adapted the inoculum layer method (ILM) developed for screening soybeans for resistance to Phytophthora rot and compared it with the traditional liquid inoculum method (LIM) for screening common beans for resistance to Fusarium root rot. In addition, two methods of evaluating resistance using the ILM were compared. The most significant Pearson correlation coefficient between trials involving 80 recombinant inbred lines was achieved with the ILM and counting discoloured vascular bundles in the lower stem (rp = 0.7113***) compared to rating the discoloration on root and hypocotyl (rp = 0.5555***). The traditional (LIM) screening method and rating the discolouration on roots resulted in a non‐significant correlation between trials (rp = 0.1084).
Glyphosate and Previous Crop Residue Effect on Deleterious and Beneficial Soil‐borne Fungi from a Peanut–Corn–Soybean Rotations
Authors: Meriles J. M. , Vargas Gil S. , Haro R. J. , March G. J. , Guzmán C. A. 
Published: April 2006

AbstractBean seedlings (Phaseolus vulgaris L.) were transplanted to soil with corn previous crop residue, peanut previous crop residue and no agricultural soil, and treated with a range of glyphosate concentrations. Trichoderma, Gliocladium, Fusarium and Pythium soil‐borne fungi populations were monitored during 24 days after glyphosate treatment to study the glyphosate and previous crop residue effects on these populations. In addition, those genera of soil‐borne fungi were tested to study in vitro toxicity to glyphosate. Independently of glyphosate concentration, the highest population of Trichoderma spp. and Gliocladium spp. were registered on soil with previous corn residue. Fusarium and Pythium populations increased proportionally to the increment of glyphosate concentration. No effect of glyphosate was founded on Trichoderma and Gliocladium populations. The in vitro study results indicated an inhibitory effect of glyphosate on mycelial grown of the most studied soil‐borne fungi.
Hyperlipidaemia, lack of sleep and smoking as risk factors for proteinuria among high altitude mountain trekkers
Authors: WADA KENTARO , MIZUGUCHI YOSHIAKI , WADA YUKO , OHNO YOUKICHI , IINO YASUHIKO 
Published: April 2006

SUMMARY:Aim:  The number of alpine accidents has been increasing among trekkers in Japan. Some of the alpine accidents have been related to acute mountain sickness (AMS). At present, the mechanism of AMS is poorly clarified, however, it is well known that hypoxia at high altitudes plays an important role. A good relation exists between proteinuria, altitude and hypoxia. However, no reports are available concerned with the risk factors of proteinuria for trekkers at high altitudes.Methods:  The authors evaluated 41 trekkers and 13 highlanders (cabin employees) through physical examinations and interviews held in a mountain cabin (2300 m above sea level) located in a mountain (2926 m above sea level) in the Japanese Alps. First, urine samples were collected and urinalysis was performed. Second, non‐invasive blood pressure, heart rate, and arterial oxygen saturation (SpO2) were measured using a portable life monitor.Results:  Proteinuria was present in 20 (49%) participants. Past history of hyperlipidaemia, amount of sleep, and smoking history are independently associated with proteinuria. Among the physiological examinations conducted at the cabin, only systolic blood pressure demonstrated strong association with proteinuria. Receiver operating characteristic curve analysis using a score combining past history of hyperlipidaemia, amount of sleep and smoking history revealed that the diagnostic accuracy of proteinuria at the cut‐off score of 2 was 80%.Conclusions:  This study indicated that these three variables were significantly and independently correlated with proteinuria: hyperlipidaemia, amount of sleep (night before) and smoking history. Improvement of these three variables might decrease the risk of alpine accidents including AMS.
Folic acid 5 or 15 mg/d similarly reduces plasma homocysteine in patients with moderate–advanced chronic renal failure
Authors: BERNASCONI AMELIA R , LISTE ANDRÉS , DEL PINO NOEMÍ , ROSA DIEZ GUILLERMO J , HEGUILÉN RICARDO M 
Published: April 2006

SUMMARY:Background:  Hyperhomocysteinaemia is an independent risk factor for cardiovascular disease with a remarkable prevalence in patients with chronic renal failure (CRF). Low doses of folic acid (FA) with or without vitamin B6 and B12 has been shown to effectively reduce plasma homocysteine (Hcy). The aim of this study was to compare the short‐term effects of two different oral doses of FA (5 vs 15 mg/d) on plasma Hcy levels in subjects suffering from moderate–severe CRF.Methods:  A double‐blind, double‐dummy, comparative, two‐stage randomised study was performed. Seventeen patients aged 45–71 years, with glomerular filtration rates between 15.4–50 mL/min 1.73/m2 were randomly assigned to receive FA 5 mg/d (FA‐5, n: 8) or FA 15 mg/d (FA‐15, n: 9) for 30 days. At the end of this 30‐day double‐blind period, all the participants were placed on FA 5 mg/d (open period), for 5 additional months. Both groups were also supplemented with vitamins B1, B6 and B12 throughout the trial. Blood samples were drawn at 0, 15, 30, 90 and 180 days to assess Hcy, complete blood count (CBC) and sequential multichannel analysis (SMA). Chest X‐ray and a 12‐lead electrocardiogram (ECG) were also performed.Results:  Plasma Hcy (mean ± SEM) decreased from 27.9 ± 1.4 (baseline) to 15.1 ± 0.6, 13.3 ± 0.9, 14.1 ± 0.5 and 13.8 ± 0.5 µmol/L (FA‐5) and from 28.8 ± 2.7 to 15.6 ± 1.2, 14.4 ± 1.3, 13.0 ± 0.7 and 13.1 ± 0.6 µmol/L (FA‐15) at days 15, 30, 90 and 180, respectively. (P < 0.01 from day 15 to 180 vs baseline for both groups with no differences between them). Renal function remained stable throughout the entire period of the study in all but one patient in whom it deteriorated to pre‐end stage disease. No adverse cardiovascular events developed during the trial.Conclusion:  Both folic acid doses induced a significant and similar decrease in plasma Hcy in subjects with moderate–severe chronic renal failure. The possible dose‐related effect of this approach in reducing the risk of accelerated sclerotic vascular disease and cardiovascular events in this especially vulnerable population should be a matter of further investigation.