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71.
A simple and rapid method for the determination of naturally occurring, potentially hazardous glycoalkaloids (GAs) in potatoes
and their products has been developed. The procedure is based on the on-line solid-phase extraction of the acetic acid extracts
from potato products and combined with liquid chromatography (LC)-mass spectrometry (MS) in a fully automated system (Symbiosis™,
Spark Holland Instruments, Emmen, The Netherlands). As sorbent material HySphere™ 18HD was used for alkaloid enrichment. GAs
were eluted with the LC gradient and directly analysed by MS. Detection of the analytes was achieved in the sensitive multiple
reaction monitoring mode using two characteristic ions (m/z 98 as a qualifier for GAs and m/z 868.3 as a quantifier for α-solanine or m/z 852.4 for α-chaconine). Typical validation data for method precision (v
k α-solanine = 5.3–6.5, v
k α-chaconine = 3.4–15.4), accuracy (average recovery of α-solanine = 84%, average recovery of α-chaconine = 87%) and linearity
over the range from 1 to 1,000 ng ml−1 (R
2 = 0.9915 for α-solanine, R
2 = 0.9939 for α-chaconine) with detection limits of 0.3 ng ml−1 for α-chaconine and 0.5 ng ml−1 for α-solanine were obtained. GA contents of commercial potato products were determined by the new on-line method and afterwards
compared with those obtained with an established high-performance LC routine procedure. Better performance of the on-line
procedure was obvious from the standard deviations of both methods. Other advantages included a strong reduction of overall
analysis time, human intervention and solvent consumption as well as waste production. The time required for the on-line analysis
was 5 min, which would allow processing of almost 100 samples in 8 h. 相似文献
72.
E. Melanie DuPuis 《Agriculture and Human Values》2000,17(3):285-295
The advent of rBGH (recombinant bovinegrowth hormone) has spurred the establishment of anorganic milk industry. The food systems/commoditychain
analytical framework cannot fully explain therise of this new food. An adequate understanding ofthe consumer's role in the
food system/commodity chainrequires more attention to consumption as a form ofpolitics. One way to do this is to look at thepolitics
of other new social movements, especiallythose contesting mainstream notions of risk. From thisapproach, organic milk consumption
challenges rBGHfrom a ``Not-in-my-Body' or ``NIMB' politics of refusal,similar to the political refusal of neighborhoodresidents
in ``Not-in-My-Backyard' or ``NIMBY'environmental movements. The NIMB form of politics isnot a social movement of politically
consciousconsumers, yet it is still a political activity inwhich consumers participate in the formation of theindustry through
a process of ``reflexive consumption.'An analysis of producer-consumer discourse on milkcartons reveals the nature of this
political formation. 相似文献
73.
Ronan A. Mullins Carlos Sanchez Villamil Hilde de Rooster Anne Kummeling Robert N. White Kelley M. Thieman Mankin Michael S. Tivers Donald A. Yool Davina M. Anderson Kathryn M. Pratschke Ines Gordo Herve Brissot Ameet Singh Melanie Olive Jean Phillipe Billet Laura E. Selmic Barbara M. Kirby 《Veterinary surgery : VS》2019,48(2):164-172
74.
Context
Increasing demands on land for agriculture have resulted in large-scale clearance and fragmentation of forests globally. In fragmented landscapes, species that tolerate or exploit the matrix will persist, while those that do not, frequently decline. Knowledge of matrix use is therefore critical to predicting extinction proneness of species in modified landscapes and defining the value of land for conservation management.Objectives
In a fragmented landscape consisting of seven remnant patches surrounded by agricultural land and a large Eucalyptus forest, we explored (i) population connectivity of common ringtail possums, Pseudocheirus peregrinus, to determine the permeability of the agricultural matrix, and (ii) genetic consequences of forest fragmentation.Methods
238 common ringtail possums were screened at 14 microsatellite markers and analysed using a range of genetic techniques.Results
We observed significant genetic differentiation among all patches and limited dispersal through the agricultural matrix, even between neighbouring patches. Consequences of this were a six- to ten-fold increase in genetic dissimilarity over an equivalent geographic distance across patches compared with sites in the continuous forest and a significant reduction in genetic diversity, particularly in patches that were geographically more isolated from their neighbours.Conclusions
We conclude that the agricultural matrix has a number of characteristics that make it unsuitable for facilitating movement of possums through this landscape, and recommend several management strategies to mitigate the impacts of fragmentation on this and other arboreal species for their conservation.75.
76.
Baumgartner C Bollerhey M Henke J Wagner S Ungerer M Erhardt W 《Veterinary anaesthesia and analgesia》2008,35(2):100-112
OBJECTIVE: To evaluate the cardiovascular effects of intravenous propofol in rabbits. STUDY DESIGN: Randomized, prospective, experimental study. ANIMALS: Thirty-one female New Zealand White rabbits. METHODS: Rabbits were allocated to one of two groups [propofol (P) or conscious (C)]. In C (n = 16) vascular dimensions were measured using ultrasound of the left common carotid artery (ACC) and the abdominal aorta (AA). Group P (n = 15) received propofol 4.0-8.0 mg kg(-1) intravenously (IV). Anaesthesia was maintained with propofol at 1.2-1.3 mg kg(-1) minute(-1). Subsequently, three propofol injections (8 mg kg(-1)) were given. Before and for 10 minutes after each injection the following vascular and haemodynamic variables were recorded (a) at the ACC after the first injection; and (b) at the AA after the second injection: vessel diameter [D, (mm)], peak systolic, minimum diastolic, end-diastolic and average blood flow velocities [psBFV, mdBFV, edBFV, Vave (cm second(-1))], average volumetric flow [VFave (mL s(-1))], resistance index (RI) and pulsatility index (PI) mean arterial pressure (MAP), heart rate (HR), arterial oxygen saturation (SpO(2)) and end-tidal CO(2) (Pe'CO(2)). Echocardiography was performed after the third propofol bolus injection to investigate changes in cardiac parameters [fractional shortening, FS (%)]. RESULTS: Intravenous propofol injections caused a significant decrease in vessel diameter, volumetric flow and edBFV, and significant increases in psBFV, RI and PI. Baseline levels for vessel diameter and psBFV were restored 6-8 minutes after injection. Propofol injection decreased FS significantly by 7 minutes after injection while MAP and HR were significantly reduced for 4 minutes. CONCLUSION AND CLINICAL RELEVANCE: Injections of propofol (8 mg kg(-1)) produced an immediate, transient decrease in vascular diameters, a significant decrease in ventricular performance and an increase in peripheral vascular resistance (ACC and AA). Propofol should probably not be or only carefully used in rabbits with ventricular dysfunction. 相似文献
77.
Charles M. Roe Van P. T. H. To Yangen Zhou Guillaume Salze Melanie A. Rhodes Terry Hanson D. Allen Davis 《Journal of the World Aquaculture Society》2019,50(2):406-419
Florida pompano perform well on soy‐based, low‐animal protein diets. These diets may be improved through the use of enzymes as a feed supplement or as pretreatment of the soy product prior to inclusion. Novel soy products produced through enzyme treatment or fermentation often have higher protein content and lower levels of indigestible carbohydrates. Two trials were conducted to evaluate the potential of enzyme supplements. The first trial evaluated the effects of carbohydrase supplementation to diets based on two different soybean meals (commodity or selectively bred meal). Pompano fed the selected soybean had significantly improved growth rates and feed efficiency, while enzymatic supplementation had no significant effect on fish performance. However, enzyme supplementation increased phosphorus and energy retention when added to diets based on commodity soybean meal. Carbohydrase supplementation improved dry matter digestibility in commodity soy‐based diets but had no significant effect on selected soybean‐based diets. The second growth trial consisted of an increasing inclusion of an enzymatically treated soybean meal product (NutriVance). Results indicate that NutriVance can replace the totality of commodity soybean without impacting fish performance. Digestibility of the commodity soy, NutriVance, and a fermented soybean meal (Pepsoygen) was also evaluated, with no detectable difference in digestibility values. 相似文献
78.
Treatment of antibiotics and antibiotic resistant bacteria in swine wastewater with free chlorine 总被引:2,自引:0,他引:2
Qiang Z Macauley JJ Mormile MR Surampalli R Adams CD 《Journal of agricultural and food chemistry》2006,54(21):8144-8154
Recent recognition of the occurrence of antibiotics in the environment has highlighted concerns regarding potential threats of antibiotics to humans and wildlife. Antibiotics are commonly applied to animals to prevent diseases and promote growth, making livestock agriculture a major source of antibiotic pollution. The purpose of our study was to examine chlorination technology as a method for preventing the release of antibiotics as well as antibiotic-resistant bacteria into the environment from concentrated animal feeding operations. Wastewaters from various sites of two anaerobic lagoon systems, one aerated and the other not, on a swine facility were investigated. Each system consisted of a primary treatment lagoon and a subsequent polishing lagoon. Free chlorine (or monochloramine for comparison) was applied to oxidize antibiotics and to disinfect lagoon bacteria as well. Results indicate that aeration substantially improves lagoon functionality, thereby adding both organic and ammonia removal. Ammonia present in the wastewaters plays a critical role in antibiotics decomposition and bacterial inactivation due to its rapid competition for free chlorine to form monochloramine. Generally, a chlorine dose close to breakpoint is required to achieve complete removal of antibiotics, leading to high consumption of free chlorine in most of the wastewaters examined. However, because of a low ammonia concentration in the polishing lagoon wastewater of the aerated system, a chlorine dose of 100 mg/L can effectively achieve complete removal of both antibiotics and bacteria. On the basis of our experimental findings, a possible strategy for the treatment of swine wastewater is suggested. 相似文献
79.
Logan SM Chen W Aubry A Gidney MA Lacelle S St Michael F Kuolee R Higgins M Neufeld S Cox AD 《Veterinary microbiology》2006,116(1-3):175-186
Previous structural studies of the lipopolysaccharides from the veterinary pathogens Mannheimia haemolytica (Mh), Actinobacillus pleuropneumoniae (Ap) and Pasteurella multocida (Pm) had identified a conserved inner core oligosaccharide structure that was present in all strains investigated. In order to examine the potential of this inner core structure as a vaccine, a mutagenesis strategy was adopted to interrupt a D-glycero-D-manno-heptosyltransferase gene (losB) of Mh. This gene encodes the enzyme responsible for the addition of a D-glycero-D-manno-heptose residue, the first residue beyond the conserved inner core, and its inactivation exposed the conserved inner core structure as a terminal unit on the mutant LPS molecule. Subsequent analyses confirmed the targeted structure of the mutant LPS had been obtained, and complementation with losB in trans confirmed that the losB gene encodes an alpha-1,6-D-glycero-D-manno-heptosyltransferase. Monoclonal antibodies raised in mice to this LPS structure were found to recognise LPS and whole-cells of the truncated mutant and wild-type Mh. The antibodies were bactericidal against a wild-type Mh strain and were able to passively protect mice in a model of Mh disease. This illustrates that it is possible to raise functional antibodies against the conserved inner core LPS structure. 相似文献
80.
Meyer-Luehmann M Coomaraswamy J Bolmont T Kaeser S Schaefer C Kilger E Neuenschwander A Abramowski D Frey P Jaton AL Vigouret JM Paganetti P Walsh DM Mathews PM Ghiso J Staufenbiel M Walker LC Jucker M 《Science (New York, N.Y.)》2006,313(5794):1781-1784
Protein aggregation is an established pathogenic mechanism in Alzheimer's disease, but little is known about the initiation of this process in vivo. Intracerebral injection of dilute, amyloid-beta (Abeta)-containing brain extracts from humans with Alzheimer's disease or beta-amyloid precursor protein (APP) transgenic mice induced cerebral beta-amyloidosis and associated pathology in APP transgenic mice in a time- and concentration-dependent manner. The seeding activity of brain extracts was reduced or abolished by Abeta immunodepletion, protein denaturation, or by Abeta immunization of the host. The phenotype of the exogenously induced amyloidosis depended on both the host and the source of the agent, suggesting the existence of polymorphic Abeta strains with varying biological activities reminiscent of prion strains. 相似文献