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41.
Five 20-week-old tom turkeys from a flock of range turkeys were presented for examination; the flock had a history of salivation, tremors, paralysis, and increased mortality. Necropsy revealed numerous seeds identified as seeds from Conium maculatum (poison hemlock) within the crop, proventriculus, and gizzard. Histopathologic alterations were limited to catarrhal enteritis. Clinical signs of Conium maculatum toxicosis abated after the turkeys were removed from their range, which was infested with poison hemlock. 相似文献
42.
Recent attempts to address land degradation have seen calls for greater integration of scientific expertise with local knowledges. In this paper we investigate the potential for such combined understandings to enhance the accuracy, coverage and relevance of land degradation assessment. We followed a participatory approach, using methods from a variety of disciplines, to elicit potential land degradation indicators from communities in Botswana and Swaziland. These indicators were then assessed according to local and scientific understandings. We noted a significant overlap between scientific and local knowledges about land degradation in most instances. Where discrepancies occurred, the integrated participatory approach we used allows appropriate explanation to be reached, supporting the case that such an iterative process can lead to both accurate and relevant monitoring of land degradation. However, the incorporation of integrated knowledges into national policy has not been widespread in either country, suggesting that much greater efforts are required to institutionalise participatory land degradation assessment methodologies. Powerful, often neo‐Malthusian narratives of degradation continue to dominate policy discourse and limit the extent to which hybrid combined local and scientific knowledges can enhance land degradation assessment on a national and regional scale. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
43.
Gregory SM Davis BK West JA Taxman DJ Matsuzawa S Reed JC Ting JP Damania B 《Science (New York, N.Y.)》2011,331(6015):330-334
The NLR (nucleotide binding and oligomerization, leucine-rich repeat) family of proteins senses microbial infections and activates the inflammasome, a multiprotein complex that promotes microbial clearance. Kaposi's sarcoma-associated herpesvirus (KSHV) is linked to several human malignancies. We found that KSHV Orf63 is a viral homolog of human NLRP1. Orf63 blocked NLRP1-dependent innate immune responses, including caspase-1 activation and processing of interleukins IL-1β and IL-18. KSHV Orf63 interacted with NLRP1, NLRP3, and NOD2. Inhibition of Orf63 expression resulted in increased expression of IL-1β during the KSHV life cycle. Furthermore, inhibition of NLRP1 was necessary for efficient reactivation and generation of progeny virus. The viral homolog subverts the function of cellular NLRs, which suggests that modulation of NLR-mediated innate immunity is important for the lifelong persistence of herpesviruses. 相似文献
44.
Foster MS Edwards MS Reed DC Schiel DR Zimmerman RC 《Science (New York, N.Y.)》2006,313(5794):1737-9; author reply 1737-9
45.
Buckwheat (Fagopyrum esculentum Moench) protein (BWP) exhibits hypocholesterolemic activity in several animal models by increasing fecal excretion of neutral and acidic sterols. In the current study, the ability of BWP to disrupt micelle cholesterol solubility by sequestration of cholesterol was investigated. When BWP (0.2%) was incubated with cholesterol and micelle lipid components prior to micelle formation, cholesterol solubility was reduced 40%. In contrast, cholesterol solubility was not decreased when BWP (0.2%) was incubated after micelle formation and incorporation of soluble cholesterol. Buckwheat flour, from which BWP was derived, had no significant effect on cholesterol solubility. Cholesterol uptake in Caco-2 cells from micelles made in the presence of BWP (0.2%) was reduced by 47, 36, 35, and 33% when compared with buckwheat flour, bovine serum albumin, casein, and gelatin, respectively. Reduction in cholesterol uptake in Caco-2 cells was dose-dependent, with maximum reductions at 0.1-0.4% BWP. In cholesterol-binding experiments, 83% of the cholesterol was associated with an insoluble BWP fraction, indicating strong cholesterol-binding capacity that disrupts solubility and uptake by Caco-2 cells. 相似文献
46.
Pal SK Itkis ME Tham FS Reed RW Oakley RT Haddon RC 《Science (New York, N.Y.)》2005,309(5732):281-284
An organic material composed of neutral free radicals based on the spirobiphenalenyl system exhibits a room temperature conductivity of 0.3 siemens per centimeter and a high-symmetry crystal structure. It displays the temperature-independent Pauli paramagnetism characteristic of a metal with a magnetic susceptibility that implies a density of states at the Fermi level of 15.5 states per electron volt per mole. Extended Hückel calculations indicate that the solid is a three-dimensional organic metal with a band width of approximately 0.5 electron volts. However, the compound shows activated conductivity (activation energy, 0.054 electron volts) and an optical energy gap of 0.34 electron volts. We argue that these apparently contradictory properties are best resolved in terms of the resonating valence-bond ground state originally suggested by Pauling, but with the modifications introduced by Anderson. 相似文献
47.
Jaya Das Samira H. Daroub Jehangir H. Bhadha Timothy A. Lang Orlando Diaz Willie Harris 《Journal of Soils and Sediments》2012,12(6):952-965
Purpose
Excess nutrients such as phosphorus (P) transported from the Everglades Agricultural Area (EAA) in South Florida, USA, to downstream water bodies have been identified as contributing to trophic imbalances within the Florida Everglades. Decades of farming drainage from the EAA has led to accumulation of sediments in regional canals which may be transported to downstream ecosystems and act as potential internal source of P.Materials and methods
Intact sediment cores were collected from three main conveyance and three farm canals within the EAA. Physicochemical assessment, mineralogy, P speciation, and storage were determined for surface and subsurface layers.Results and discussion
The main conveyance canal sediments had higher total P (TP) concentrations (1,280?±?360?mg?kg-1) than the farm canals (960?±?540?mg?kg-1), while farm canal sediments showed higher organic matter content (28?C53?%) compared to the main canal (24?C27?%) sediments. The minerals found in main conveyance canal sediments were similar to those found in Lake Okeechobee. The labile KCl?CP fraction comprised <2?% of TP from all canal sediments, while NaOH?CPi (i?=?inorganic) fraction consisted of 1?C14?% of TP. The majority of P in the canal sediments was contained in the HCl?CP fraction (Ca?CP and Mg?CP), comprising >50?% of TP in the main and farm canal sediments. An estimated 73 metric tons (mt) of P was stored in the 0?C10-cm layer of the three main conveyance canals within the EAA boundary of which 57-mt P is reactive and potentially available for release at different time scales.Conclusions
The EAA canal sediments are highly organic with low bulk density and susceptible of being transported to downstream ecosystems. Many factors can impact the potential release of the reactive stored P, including redox potential of sediments as well as the overlying water column P concentration. Further investigation of potential P release from these sediments is warranted. 相似文献48.
R S Elfers W M Bayly D F Brobst S M Reed H D Liggitt C D Hawker D J Baylink 《The Cornell veterinarian》1986,76(3):317-329
The changes in serum and urinary levels of calcium and phosphorus and serum parathyroid hormone (PTH) were studied during controlled, chemically induced, acute renal disease in 4 ponies. There was an initial rise in daily urinary calcium and hydroxyproline excretion in 2 ponies which may have indicated increased bone resorption. Mild hypercalcemia, hypophosphatemia and elevated C-terminal PTH levels were associated with oliguria. Total daily urinary excretion of calcium and phosphorus decreased as oliguria developed. The levels of C-terminal PTH were increased in all four animals. This appears to have been related to their diminished renal function in that C-terminal fragments of intact PTH (which require functioning kidneys in order to be cleared) were probably being accumulated. Although there was no evidence with regard to an actual increase in PTH secretion, prolongation of intact PTH half-life due to renal tubular damage may have contributed to the development of hypercalcemia. 相似文献
49.
50.
Seven balloons were launched successfully from Ascension Island in January 1969. The balloons, flown at altitudes of 20 and 24 kilometers, will make possible a detailed analysis of the stratospheric circulation near the equator and will hopefully lead to an understanding of the quasi-biennial stratospheric oscillation in the tropics. 相似文献