Multiple resistance of Papaver rhoeas L. to 2,4‐D and acetolactate synthase inhibitors in four European countries

The issue of cross‐ or multiple resistance to acetolactate synthase (ALS) inhibitors and the auxinic herbicide 2,4‐D was investigated in Papaver rhoeas L., a common and troublesome weed in winter cereals, in a broad‐scale study across four European countries. A combination of herbicide sensitivity bioassays and molecular assays targeting mutations involved in resistance was conducted on 27 populations of P. rhoeas originating from Greece (9), Italy (5), France (10) and Spain (3). Plants resistant to the field rate of 2,4‐D were observed in 25 of the 27 populations assayed, in frequencies ranging from 5% to 85%. Plants resistant to ALS‐inhibiting herbicides (sulfonylureas) were present in 24 of the 27 populations, in frequencies ranging from 4% to 100%. Plants resistant to 2,4‐D co‐occurred with plants resistant to sulfonylureas in 23 populations. In four of these, the probability of presence of plants with cross‐ or multiple resistance to 2,4‐D and sulfonylureas was higher than 0.5. ALS genotyping of plants from the field populations or of their progenies, identified ALS alleles carrying a mutation at codon Pro197 or Trp574 in 2,4‐D‐sensitive and in 2,4‐D‐resistant plants. The latter case confirmed multiple resistance to 2,4‐D and ALS inhibitors at the level of individual plants in all four countries investigated. This study is the first to identify individual plants with multiple resistance in P. rhoeas, an attribute rarely assessed in other weed species, but one with significant implications in designing chemical control strategies.     

Biomass dynamics of Erythrina lanceolata as influenced by shoot-pruning intensity in Costa Rica

Pruning of agroforestry trees, while reducing shade of the crops, usually reduces both biomass production and nitrogen fixation. Short pruning cycles are often not sustainable on the long run, because tree production declines over subsequent pruning cycles. We compared biomass and labile carbohydrate dynamics of Erythrina lanceolata Standley (Papilionaceae) shade trees under total and partial pruning regimes in a vanilla (Vanilla planifolia L.) plantation in South-western Costa Rica. The highest biomass production was measured in the unpruned control, followed by trees with 50% of the leaf pruned every three months, while total pruning every six months resulted in the lowest biomass pruduction. In the more productive treatments, a higher proportion of the production was in branches. Because, the N content of woody branches was high, they were important for nitrogen cycling. In the partial pruning treatment more nitrogen was returned to the soil from litter and woody branches than from pruned leaf. Sugar concentrations were not different between treatments and the dynamics of non-structural carbohydrates (sugar and starch) seems to depend more on plant phenology than pruning treatment. However, the starch concentrations in the total pruning were lower than in the other treatments.This revised version was published online in November 2005 with corrections to the Cover Date.     

Acclimation of photosynthetic capacity in Scots pine to the annual cycle of temperature

Coniferous trees growing in the boreal and temperate zones have a clear annual cycle of photosynthetic activity. A recent study demonstrated that the seasonal variation in photosynthetic capacity of Scots pine (Pinus sylvestris L.) could be attributed mainly to the light response curve of photosynthesis. The magnitude of the light response curve varied over the season while its shape remained constant, indicating that the two physiological parameters quantifying the curve-the quantum yield per unit internal carbon dioxide concentration and the corresponding light-saturated rate-remained proportional to each other. We now show, through modeling studies, that the quantum yield (and hence the light-saturated rate) is related to the annual cycle of temperature through a delayed dynamic response. The proposed model was tested by comparing model results with intensive measurements of photosynthesis and driving variables made from April to October in three shoots of Scots pine growing near the northern timberline. Photosynthetic capacity showed considerable acclimation during the growing season. A single model describing photosynthetic capacity as a reversible, first-order delay process driven by temperature explained most of the variation in photosynthetic capacity during the year. The proposed model is simpler but no less accurate than previous models of the annual cycle of photosynthetic capacity.     

Diagnostic evaluation and short-term outcome as indicators of long-term prognosis in horses with findings suggestive of inflammatory bowel disease treated with corticosteroids and anthelmintics

Background

Recurrent colic and unexplained weight loss despite good appetite and adequate feeding and management practices are common conditions in the horse. However, little information has been published on the systematic diagnostic evaluation, response to treatment, prognostic factors or outcome of either presentation. The aims of this study were to 1) identify possible prognostic indicators and 2) report the short- and long-term response to treatment with corticosteroid therapy of a variety of horses with a presumptive diagnosis of inflammatory bowel disease (IBD).Thirty-six horses with a history of recurrent colic and/or unexplained weight loss were screened with a detailed clinical, clinicopathological and diagnostic imaging examination. Twenty horses were subsequently selected that had findings consistent with inflammatory bowel disease based on the fulfilment of one or more of the following additional inclusion criteria: hypoproteinaemia, hypoalbuminaemia, malabsorption, an increased intestinal wall thickness on ultrasonographic examination or histopathological changes in rectal biopsy. These 20 horses were treated with a standardized larvicidal anthelmintic regime and a minimum of three weeks of corticosteroid therapy.

Results

The initial response to treatment was good in 75% (15/20) of horses, with a 3-year survival rate of 65% (13/20). The overall 3-year survival in horses that responded to initial treatment (12/15) was significantly higher (P = 0.031) than in those that did not respond to initial treatment (1/5). The peak xylose concentration was significantly (P = 0.048) higher in survivors (1.36 ± 0.44 mmol/L) than non-survivors (0.94 ± 0.36 mmol/L).

Conclusions

The overall prognosis for long-term survival in horses with a presumptive diagnosis of IBD appears to be fair to moderate, and the initial response to anthelmintic and corticosteroid therapy could be a useful prognostic indicator. The findings of the present study suggest that a low peak xylose concentration in absorption testing is associated with a less favourable prognosis, supporting the use of this test.     

A comparison in dogs of medetomidine,with or without MK‐467, and the combination acepromazine‐butorphanol as premedication prior to anaesthesia induced by propofol and maintained with isoflurane

ObjectiveTo compare the haemodynamic effects of three premedicant regimens during propofol-induced isoflurane anaesthesia.Study designProspective, randomized cross-over study.AnimalsEight healthy purpose-bred beagles aged 4 years and weighing mean 13.6 ± SD 1.9 kg.MethodsThe dogs were instrumented whilst under isoflurane anaesthesia prior to each experiment, then allowed to recover for 60 minutes. Each dog was treated with three different premedications given intravenously (IV): medetomidine 10 μg kg^?1 (MED), medetomidine 10 μg kg^?1 with MK-467 250 μg kg^?1 (MMK), or acepromazine 0.01 mg kg^?1 with butorphanol 0.3 mg kg^?1 (AB). Anaesthesia was induced 20 minutes later with propofol and maintained with isoflurane in oxygen for 60 minutes. Heart rate (HR), cardiac output, arterial blood pressures (ABP), central venous pressure (CVP), respiratory rate, inspired oxygen fraction, rectal temperature (RT) and bispectral index (BIS) were measured and arterial and venous blood gases analyzed. Cardiac index (CI), systemic vascular resistance index (SVRI), oxygen delivery index (DO₂I), systemic oxygen consumption index (VO₂I) and oxygen extraction (EO₂) were calculated. Times to extubation, righting, sternal recumbency and walking were recorded. The differences between treatment groups were evaluated with repeated measures analysis of covariance.ResultsHR, CI, DO₂I and BIS were significantly lower with MED than with MMK. ABP, CVP, SVRI, EO₂, RT and arterial lactate were significantly higher with MED than with MMK and AB. HR and ABP were significantly higher with MMK than with AB. However, CVP, CI, SVRI, DO₂I, VO₂I, EO₂, T, BIS and blood lactate did not differ significantly between MMK and AB. The times to extubation, righting, sternal recumbency and walking were significantly shorter with MMK than with MED and AB.Conclusions and clinical relevanceMK-467 attenuates certain cardiovascular effects of medetomidine in dogs anaesthetized with isoflurane. The cardiovascular effects of MMK are very similar to those of AB.     

Manufacture and characterization of pasta made with wheat flour rendered gluten-free using fungal proteases and selected sourdough lactic acid bacteria

Wheat flour, which was rendered gluten-free by sourdough lactic acid bacteria fermentation and fungal proteases, was used for manufacturing experimental gluten-free pasta (E-GFp), according to a traditional process with low temperature drying cycle. Chemical, technological, structural, nutritional and sensory features were characterized and compared with those of commercial gluten-free (C-GFp) and durum wheat pasta (C-DWp). As shown through immunological analyses, the residual concentration of gluten of the hydrolyzed wheat flour was below 10 ppm. E-GFp showed rapid water uptake and shorter optimal cooking time compared to the other pastas. Despite the absence of the gluten network, the supplementation with pre-gelatinized rice flour allowed structural properties of E-GFp, which were comparable to those of C-GFp. The in vitro protein digestibility of E-GFp resulted the highest. Probably due to proteolysis during sourdough fermentation; chemical scores, essential amino acid profile, biological value and nutritional index of E-GFp were higher than those of C-DWp. The hydrolysis index (HI) of E-GFp was ca. 30% lower than that found for C-GFp. As shown by sensory analysis, the characteristic of E-GFp were acceptable. The manufacture of E-GFp should be promising to expand the choice of gluten-free foods, which combine sensory and nutritional properties.     

Conservation management for Orthoptera in the Dadia reserve, Greece

The diversity patterns, the ecological structure and the typical species of the orthopteran assemblage in the Dadia reserve are investigated. The reserve was designed to protect the black vulture (Aegypius monachus) and other raptors. A total of 39 orthopteran species were found, including Paranocarodes chopardi, a pamphagid species with very restricted distribution. All species can be represented in a network of six complementary habitats, including open oak woodlands, agricultural fields separated with hedges, humid grasslands, as well as serpentine grasslands. The buffer zone of the reserve is far more important for Orthoptera conservation than the core areas, which host most of the black vulture nests. Management focusing on raptors is in general compatible with conservation of Orthoptera. We suggest the maintenance of forest openings in the buffer zone, the maintenance of forest heterogeneity, the enhancement of periodical livestock grazing, and the use of nine indicator species and Paranocarodes chopardi in the reserve monitoring program.     

Laboratory diagnosis of African horse sickness: comparison of serological techniques and evaluation of storage methods of samples for virus isolation

Five serological methods of diagnosing African horse sickness were evaluated, using a battery of serum samples from experimental horses vaccinated and challenged with each serotype of African horse sickness virus (AHSV1 through AHSV9): agar gel immunodiffusion (AGID), indirect fluorescent antibody (IFA), complement fixation (CF), virus neutralization (VN), and enzyme-linked immunosorbent assay (ELISA). The 5 tests were also compared using a panel of field samples, convalescent equine sera with antibodies to domestic equine viral diseases, and sera from horses awaiting export. The ELISA described in this paper was group specific. It did not require calibration with a standard positive serum but did yield elevated values with negative sera that were repeatedly frozen and thawed or heat inactivated. The IFA test was sensitive but could not be used on some field sera as the control cells exhibited fluorescence, possibly due to the animal being recently vaccinated with cell culture material. Sixty-two experimental sera were compared by VN, CF, AGID, and ELISA. Forty sera, 10 positive and 30 negative, were correctly classified by the 5 serologic assays. The 22 remaining sera gave mixed reactions. The AGID had no false positive results but had false negative results for up to 20% of the samples, depending upon the comparison. The VN, CF, and ELISA were similar in their variability. The length of time that virus could be recovered from a viremic blood sample was compared in an evaluation of storage methods for virus isolation samples. Washed erythrocytes were held at 4 C, washed erythrocytes plus stabilizer were held at -70 C, and blood that was drawn into a preservative (oxalate/phenol/glycerol) was held at 4 C.(ABSTRACT TRUNCATED AT 250 WORDS)