We compared the seedbanks, seed rains, plant densities and biomasses of weeds under two contrasting systems of management in beet, maize and spring oilseed rape. Weed seedbank and plant density were ...measured at the same locations in two subsequent seasons. About 60 fields were sown with each crop. Each field was split, one half being sown with a conventional variety managed according to the farmer's normal practice, the other half being sown with a genetically modified herbicide-tolerant (GMHT) variety, with weeds controlled by a broad-spectrum herbicide. In beet and rape, plant densities shortly after sowing were higher in the GMHT treatment. Following weed control in conventional beet, plant densities were approximately one-fifth of those in GMHT beet. In both beet and rape, this effect was reversed after the first application of broad-spectrum herbicide, so that late-season plant densities were lower in the GMHT treatments. Biomass and seed rain in GMHT crops were between one-third and one-sixth of those in conventional treatments. The effects of differing weed-seed returns in these two crops persisted in the seedbank: densities following the GMHT treatment were about 20% lower than those following the conventional treatment. The effect of growing maize was quite different. Weed density was higher throughout the season in the GMHT treatment. Late-season biomass was 82% higher and seed rain was 87% higher than in the conventional treatment. The difference was not subsequently detectable in the seedbank because the total seed return was low after both treatments. In all three crops, weed diversity was little affected by the treatment, except for transient effects immediately following herbicide application.
Effects of genetically modified herbicide-tolerant (GMHT) and conventional crop management on invertebrate trophic groups (herbivores, detritivores, pollinators, predators and parasitoids) were ...compared in beet, maize and spring oilseed rape sites throughout the UK. These trophic groups were influenced by season, crop species and GMHT management. Many groups increased twofold to fivefold in abundance between early and late summer, and differed up to 10-fold between crop species. GMHT management superimposed relatively small (less than twofold), but consistent, shifts in plant and insect abundance, the extent and direction of these effects being dependent on the relative efficacies of comparable conventional herbicide regimes. In general, the biomass of weeds was reduced under GMHT management in beet and spring oilseed rape and increased in maize compared with conventional treatments. This change in resource availability had knock-on effects on higher trophic levels except in spring oilseed rape where herbivore resource was greatest. Herbivores, pollinators and natural enemies changed in abundance in the same directions as their resources, and detritivores increased in abundance under GMHT management across all crops. The result of the later herbicide application in GMHT treatments was a shift in resource from the herbivore food web to the detritivore food web. The Farm Scale Evaluations have demonstrated over 3 years and throughout the UK that herbivores, detritivores and many of their predators and parasitoids in arable systems are sensitive to the changes in weed communities that result from the introduction of new herbicide regimes.
Following injury to the mammalian CNS, axons sprout in the vicinity of the wound margin. Growth then ceases and axons fail to cross the lesion site. In this study, using dopaminergic sprouting in the ...injured striatum as a model system, we have examined the relationship of periwound sprouting fibers to reactive glia and macrophages. In the first week after injury we find that sprouting fibers form intimate relationships with activated microglia as they traverse toward the wound edge. Once at the wound edge, complicated plexuses of fibers form around individual macrophages. Axons, however, fail to grow further into the interior of the wound despite the presence of many macrophages in this location. We find that the expression of BDNF by activated microglia progressively increases as the wound edge is approached, while GDNF expression by macrophages is highest at the immediate wound margin. In contrast, the expression of both factors is substantially reduced within the macrophage-filled interior of the wound. Our data suggest that periwound sprouting fibers grow toward the wound margin along an increasing trophic gradient generated by progressively microglial and macrophage activation. Once at the wound edge, sprouting ceases over macrophages at the point of maximal neurotrophic factor expression and further axonal growth into the relatively poor trophic environment of the wound core fails to occur.
We compared the effects of the management of genetically modified herbicide-tolerant (GMHT) and conventional beet, maize and spring oilseed rape on 12 weed species. We sampled the seedbank before and ...after cropping. During the season we counted plants and measured seed rain and biomass. Ratios of densities were used to calculate emergence, survival, reproduction and seedbank change. Treatments significantly affected the biomass of six species in beet, eight in maize and five in spring oilseed rape. The effects were generally consistent, with biomass lower in GMHT beet and spring oilseed rape and higher in GMHT maize. With few exceptions, emergence was higher in GMHT crops. Subsequent survival was significantly lowered for eight species in beet and six in spring oilseed rape in the GMHT treatments. It was increased for five species in maize and one in spring oilseed rape. Significant effects on seedbank change were found for four species. However, for many species in beet and spring oilseed rape (19 out of 24 cases), seed densities were lower in the seedbank after GMHT cropping. These differences compounded over time would result in large decreases in population densities of arable weeds. In maize, populations may increase.
Cross‐presentation involves the uptake and processing of exogenous antigens within the major histocompatibility complex (MHC) class I pathway. This process is primarily performed by dendritic cells ...(DCs), which are not a single cell type but may be divided into several distinct subsets. Those expressing CD8α together with CD205, found primarily in the T‐cell areas of the spleen and lymph nodes, are the major subset responsible for cross‐presenting cellular antigens. This ability is likely to be important for the generation of cytotoxic T‐cell immunity to a variety of antigens, particularly those associated with viral infection, tumorigenesis, and DNA vaccination. At present, it is unclear whether the CD8α‐expressing DC subset captures antigen directly from target cells or obtains it indirectly from intermediary DCs that traffic from peripheral sites. In this review, we examine the molecular basis for cross‐presentation, discuss the role of DC subsets, and examine the contribution of this process to immunity, with some emphasis on DNA vaccination.
Severe plaque-type psoriasis has been successfully treated with orally administered cyclosporine, but there has been no comparative, controlled evaluation of various dosages and their efficacy and ...side effects.
In a 16-week, double-blind trial, we randomly assigned 85 patients with severe psoriasis to receive 3, 5, or 7.5 mg of cyclosporine per kilogram of body weight per day or a placebo consisting of the vehicle for the drug. After eight weeks the dose could be adjusted to improve safety or efficacy while maintaining blinding.
The psoriasis improved in a dose-dependent fashion. After eight weeks of fixed-dose therapy, 36, 65, and 80 percent of the patients receiving 3, 5, and 7.5 mg of cyclosporine per kilogram per day, respectively, were rated as being clear or almost clear of psoriasis; each group had significant improvement (P less than 0.0001) as compared with the group receiving vehicle, in which none of the patients were rated as clear or almost clear. The patients who received 5 mg per kilogram were the least likely to require dosage adjustments because of side effects or a lack of efficacy. The glomerular filtration rate, measured in a subgroup of 34 patients receiving cyclosporine, decreased by a median of 16 percent. Higher doses of cyclosporine had greater adverse effects on systolic blood pressure, glomerular filtration rate, and serum levels of creatinine, uric acid, bilirubin, and cholesterol. Delayed-type hypersensitivity reactions to skin-test antigens were reduced by cyclosporine administration. Cyclosporine appears to become concentrated in skin.
Cyclosporine therapy leads to a rapid and thorough clearing of psoriasis; an initial dose of 5 mg per kilogram per day seems to be appropriate. However, the safety of cyclosporine for the long-term treatment of psoriasis remains to be determined.
A standardized protocol enabling rapid NMR data collection for high-quality protein structure determination is presented that allows one to capitalize on high spectrometer sensitivity: a set of five ...G-matrix Fourier transform NMR experiments for resonance assignment based on highly resolved 4D and 5D spectral information is acquired in conjunction with a single simultaneous 3D15N,13Caliphatic,13Caromatic-resolved 1H,1H- NOESY spectrum providing1H-1H upper distance limit constraints. The protocol was integrated with methodology for semiautomated data analysis and used to solve eight NMR protein structures of the Northeast Structural Genomics Consortium pipeline. The molecular masses of the hypothetical target proteins ranged from 9 to 20 kDa with an average of ≈14 kDa. Between 1 and 9 days of instrument time were invested per structure, which is less than ≈10-25% of the measurement time routinely required to date with conventional approaches. The protocol presented here effectively removes data collection as a bottleneck for high-throughput solution structure determination of proteins up to at least ≈20 kDa, while concurrently providing spectra that are highly amenable to fast and robust analysis.
Five ruminally and duodenally cannulated steers were used in a 5 X 5 Latin square design with a 2 X 2 + 1 arrangement of treatments to study the effects of barley variety and dietary barley content ...on digestive function in steers fed grass hay-based diets. Barley varieties evaluated were Russell and Steptoe, which had bulk densities of 67.7 and 64.5 kg/hL, respectively. Supplemental treatments were as follows: corn, low Russell (Ru-lo), low Steptoe (St-lo), high Russell (Ru-hi), and high Steptoe (St-hi). Corn, Ru-lo, and St-lo were provided at 30% (DM basis) of grass hay-based diets, whereas Ru-hi and St-hi were provided at 35.5% of diet DM (equal starch content as the corn treatment). No treatment differences (P 0.10) were observed for DMI, ruminal particulate passage rate, and NDF total tract digestibility. Ruminal DM and starch digestibility were greater (P 0.01) for barley-containing diets than for the corn diet. Similarly, total tract DM (P 0.10) and starch (P 0.01) digestibility was greater for barley than for corn diets. Microbial protein and non-NH3 N flow to the small intestine were greater (P 0.01) for the barley diets than for the corn diet. Starch intake (P 0.01) and DM digestibility (P 0.10) were greater for high- than for low-barley diets; however, differences due to barley variety were not observed (P 0.10). In situ disappearance of grass hay NDF at 8 and 96 h of incubation was greater (P 0.05) for barley than for corn diets. Rate of in situ disappearance of grain DM was greater (P 0.01) for barley than for corn and for Russell than for Steptoe barley. Responses suggest that ruminal and total tract digestibility and protein flow to the small intestine can be increased with barley compared with corn as an energy supplement to grass hay-based diets
This paper presents a feature detection and concealment algorithm which can conceal errors in DCT coded images. Feature detection, classification and concealment of the lost information is performed ...totally within the transform domain for such images. The reconstructed image can then be replayed, and the concealment provides a visible improvement to the regenerated image. Only three low frequency DCT coefficients are used in performing the detection and classification process, requiring only a limited amount of computation. The algorithm operates by searching for a single edge in each of the blocks surrounding the area of loss. The edge is then classified according to its angle and displacement within the block. The algorithm then calculates and implements the amount of pixel domain displacement required to produce a block that contains an edge which continues the feature through the error block. This effectively removes the visible discontinuity within the edge or feature produced by the error. This discontinuity is still present if a simpler algorithm is used based on linear interpolation techniques alone. Some results from the application of the algorithm to JPEG images are shown.
Monoclonal antibodies directed against glycoprotein D of herpes simplex virus completely inhibited fusion of Vero cells infected with type 1 virus. In contrast, several monoclonal antibodies directed ...against other viral glycoproteins, including B, were ineffective or were only minimally inhibitory at the highest concentrations tested.
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