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301.
302.
Ma'ayan A Jenkins SL Neves S Hasseldine A Grace E Dubin-Thaler B Eungdamrong NJ Weng G Ram PT Rice JJ Kershenbaum A Stolovitzky GA Blitzer RD Iyengar R 《Science (New York, N.Y.)》2005,309(5737):1078-1083
We developed a model of 545 components (nodes) and 1259 interactions representing signaling pathways and cellular machines in the hippocampal CA1 neuron. Using graph theory methods, we analyzed ligand-induced signal flow through the system. Specification of input and output nodes allowed us to identify functional modules. Networking resulted in the emergence of regulatory motifs, such as positive and negative feedback and feedforward loops, that process information. Key regulators of plasticity were highly connected nodes required for the formation of regulatory motifs, indicating the potential importance of such motifs in determining cellular choices between homeostasis and plasticity. 相似文献
303.
Rory M. Breathnach Shay Fanning Grace Mulcahy Hugh F. Bassett Eric Strobl Boyd R. Jones 《Veterinary dermatology》2010,21(4):383-392
This study characterizes T‐ and B‐lymphocyte responses in the peripheral blood and lesional skin of dogs with immunomodulatory‐responsive lymphocytic–plasmacytic pododermatitis (ImR‐LPP), a term previously proposed to denote a subpopulation of dogs with idiopathic pododermatitis. T‐cell (CD3+, CD4+ and CD8+) and B‐cell (CD21+) counts were significantly increased in both the epidermis and dermis of lesional ImR‐LPP skin compared with that in pedal skin from healthy controls. CD3+, CD4+, CD8+ and CD21+ cells were commonly observed in perivascular sites in the superficial dermis, periadnexally, beneath the dermal–epidermal (DE) junction and in the epidermis of lesional ImR‐LPP skin. The CD8+/CD3+ T‐cell ratio in peripheral blood was significantly increased in the ImR‐LPP group (0.42 versus 0.35 in controls). Serum IgA, IgG and IgM concentrations were all significantly elevated in affected dogs. Lymphocyte stimulation indices in ImR‐LPP dogs were comparable with control levels except for a lower response to ionomycin (6.0 versus 11.1). Dogs with ImR‐LPP had a higher incidence and mean (semi‐quantitative) score for IgA, IgG and IgM deposits in the epidermis, and a significantly increased incidence of dermal IgA+, IgG+ and IgM+ mononuclear inflammatory cells. The results indicate that upregulated T‐ and B‐lymphocyte responses may contribute to the pathogenesis of the skin lesions observed in dogs with ImR‐LPP. 相似文献
304.
Haibo Huang Wei Liu Vijay Singh Mary‐Grace C. Danao Steven R. Eckhoff 《Cereal Chemistry》2012,89(4):217-221
Efficiently utilizing the nongrain portion of the corn plant as ruminant food and the grain for ethanol will allow the optimization of both food and fuel production. Corn and corn stover could be more effectively used if they were harvested earlier before dry down. Corn harvested at different moisture contents (MCs) may exhibit different processing characteristics for the ethanol industry, because of differences in physical and chemical properties. Therefore, the objective of this study was to investigate the effect of corn harvest MC on dry‐grind fermentation characteristics and dried distillers grains with solubles (DDGS) composition. Pioneer hybrid 32D78 was harvested at seven different dates from August 21 to November 23, 2009, with harvest MCs ranging from 73 to 21% (wb). The corn samples with different harvest MCs were evaluated by a conventional dry‐grind process. Final ethanol concentration from the corn with harvest MC of 54% (kernel dent stage) was 17.9% (v/v), which was significantly higher (0.5–1.2 percentage points) than the mature corn with lower harvest MCs (P < 0.05). Ethanol conversion efficiencies for the corn with harvest MCs of 73 and 54% (wb) were 98.5 and 93.2%, respectively, whereas ethanol conversion efficiencies for the corn with lower harvest MCs were significantly lower (P < 0.05), ranging between 83.2 and 88.3%. For DDGS composition, with corn harvest MC decreasing from 73 to 21% (wb), the residual starch concentration increased from 7.7 to 15.2%, the crude protein concentration decreased from 29.4 to 24.9%, and the neutral detergent fiber concentration decreased from 26.6 to 20.6%. 相似文献
305.
The survey evaluated the market potential for guinea fowl (GF; Numidia meleagris) products in the city of Harare, Zimbabwe. Questionnaires were administered to traders/producers (n = 17), retailers (n = 12), cafeteria industry (n = 33) and consumers (n = 1,680) to establish their perceptions on guinea fowl products. The average household size was 6 ± 2. Each trader sold 10 ± 6.30
keets (mean ± standard error), 33 ± 15.05 growers, 20 ± 12.69 breeders and 20 ± 10.1 crates of 30 eggs per month. Each household
consumed 2.5 ± 1.39 kg of GF meat and 3 ± 0.65 dozens of GF eggs per month. Retailers purchased 52 ± 44.42 crates of GF eggs
and 41 ± 30.50/kg of GF meat whilst cafeteria purchased 33.6 ± 14 crates of GF eggs and 65.5 ± 33.52 kg of GF meat per month.
Growers for breeding were the major product for sale by traders (94.1%) at a price of US$7.50 ± 1.74/bird. Different industries
were offering different prices for guinea fowl products because of their scarcity on the market. The mean purchase price per
crate of 30 guinea fowl eggs sold to the retail and cafeteria were US$7.50 ± 1.74/bird. Different industries
were offering different prices for guinea fowl products because of their scarcity on the market. The mean purchase price per
crate of 30 guinea fowl eggs sold to the retail and cafeteria were US3.00 ± 0.58 and US$4.50 ± 0.50, respectively. The mean
purchase prices for GF meat was lower (P < 0.05) for retailers (US$4.50 ± 0.50, respectively. The mean
purchase prices for GF meat was lower (P < 0.05) for retailers (US2.5 ± 0.81/kg) than cafeteria (US$3.67 ± 0.83/kg). The challenges faced by producers in the marketing
of guinea fowl products included poor supply due to the absence of good road networks to connect source areas and the market,
perishability of dressed chickens due to power cuts and poor publicity. Overall, the study showed that there is greater market
potential for guinea fowl products and farmers can channel their products through traders, cafeteria and retail industries. 相似文献
306.
Grace Chibuike Lucy Burkitt Marta Camps‐Arbestain Peter Bishop Mike Bretherton Ranvir Singh 《Soil Use and Management》2019,35(3):453-465
Intensive agricultural activities could affect the dynamics and leaching of dissolved organic carbon (DOC) and nitrate from agricultural soils to receiving waters. This study investigated soil DOC dynamics immediately (0–12 days) after spraying a hill country perennial pasture with agrochemicals to establish a winter forage crop for supplementary feed production. Two treatments were examined—perennial pasture (without agrochemicals) and swede (Brassica napobrassica Mill.) cropping (after spraying with agrochemicals), both growing on a Typic Eutrudept. Soil samples were collected from various depths down to 1 m, before the application of agrochemicals (day 0) and 1, 6 and 12 days thereafter. Dissolved organic carbon concentration below the surface soil (<5 cm) was generally not altered by the agrochemicals. This was further proved by the isotopic monitoring of DOC leaching on this soil. Conversely, the agrochemicals significantly (p = 0.03) increased DOC concentration within the 0–5‐cm soil depth on day 1, due to the direct contribution of organic molecules and/or displacement of organic compounds at adsorption sites by the agrochemicals; and on day 6, due to root necromass decomposition. The increase of nitrate in soil solution at this depth (0–5 cm) on days 6 and 12 suggests that the agrochemicals may have also enhanced nitrogen (N) mineralization in the surface soil. However, the significantly (p = 0.04) higher DOC/nitrate (molar ratio) of the agrochemical treatment suggests that the agrochemicals used for clearing out pasture before forage crop establishment could lead to a short‐term increase in surface soil denitrification. 相似文献
307.
308.
Recent research shows that land use history is an important determinant of current ecosystem function. In the United States,
characterization of land use change following European settlement requires reconstruction of the original property mosaic.
However, this task is difficult in unsystematically surveyed areas east of the Appalachian Mountains. The Gwynns Falls watershed
(Baltimore, MD) was originally surveyed in the 1600-1700s under a system of warrants and patents (commonly known as ‘metes
and bounds’). A method for the reconstruction and mapping of warrant and patent properties is presented and used to map the
original property mosaic in the Gwynns Falls watershed. Using the mapped mosaic, the persistence of properties and property
lines in the current Gwynns Falls landscape is considered. The results of this research indicate that as in agricultural areas,
the original property lines in the Gwynns Falls watershed are persistent. At the same time, the results suggest that the property
mosaic in heavily urbanized/suburbanized areas is generally ‘reset.’ Further, trends in surveying technique, parcel size,
and settlement patterns cause property line density and property shape complexity to increase in the less urbanized upper
watershed. The persistence of original patterns may be damping expression of heterogeneity gradients in this urban landscape.
This spatial pattern of complexity in the original mosaic is directly opposite of hypothesized patterns of landscape heterogeneity
arising from urbanization. The technique reported here and the resulting observations are important for landscape pattern
studies in areas settled under unsystematic survey systems, especially the heavily urbanized areas of the eastern United States.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献