Characterization and distribution of phenolics in carrot cell walls     

Kang YH  Parker CC  Smith AC  Waldron KW 《Journal of agricultural and food chemistry》2008,56(18):8558-8564

Carrot cell walls have been shown to contain significant quantities of esterified p-hydroxybenzoic acid, which is presumed to be esterified to cell wall polymers. The purpose of this study was to investigate the distribution of p-hydroxybenzoic acid and related phenolics among carrot cell wall polysaccharides. Cell wall material was prepared from fresh carrot root tissues and extracted sequentially with water, imidazole, cyclohexane- trans-1,2-diamine- N, N, N', N'-tetraacetate, Na 2CO 3, and KOH (0.5, 1, and 4 M) to leave a cellulose-rich residue. The fractions were analyzed for their carbohydrate and phenolic acid components. Selected soluble fractions were subfractionated further by graded precipitation in ethanol. The majority of the polymer fractions comprised pectic polysaccharides, with varying quantities of neutral sugars (arabinose and galactose). Hemicellulosic polymers were generally found only in the strong alkali extracts (4 M KOH). p-OH-benzoic acid was the predominant phenolic ester and was associated with most fractions analyzed; p-OH-benzaldehyde was also detected in the fractions at much lower levels. Principal components analysis of the chemical data indicated that the p-OH-benzoic acid was associated predominantly with the branched pectic polysaccharides, in contrast to the p-OH-benzaldehyde. The possible roles and functional properties of these phenolics are discussed.  相似文献   

Peroxidase-mediated oxidative cross-linking and its potential to modify mechanical properties in water-soluble polysaccharide extracts and cereal grain residues     

Robertson JA  Faulds CB  Smith AC  Waldron KW 《Journal of agricultural and food chemistry》2008,56(5):1720-1726

Analysis of wheat bran and spent grain shows that concentrations of ferulate and diferulates offer considerable scope to modify the cross-linking of feruloylated polysaccharides and hence the mechanical properties of these residues. In solution ferulic acid (FA) can be readily polymerized by horseradish peroxidase, but when esterified to a polysaccharide, the profile of diferulates becomes restricted. This situation also exists in muro and suggests structural constraints may limit the availability of FA for cross-linking. At relatively low polysaccharide concentration, (approximately 3%), steric restrictions were apparent in gels prepared using isolated polysaccharides. Mechanical properties such as swelling also appear to be fixed at these relatively low polysaccharide concentrations. This limits the potential to modify mechanical properties in muro through oxidoreductase activity. To modify mechanical properties such treatments will need to focus on increasing the "flexibility" of the cell wall matrix and the accessibility of enzymes to the cell wall matrix.  相似文献   

Primary tracheal collapse in a cat     

Mims HL  Hancock RB  Leib MS  Waldron DR 《Journal of the American Animal Hospital Association》2008,44(3):149-153

A 7-year-old, neutered male, domestic shorthair cat was presented for severe inspiratory dyspnea of 2 to 3 days' duration. Radiography and tracheobronchoscopy confirmed the diagnosis of primary extrathoracic tracheal collapse. The cat was treated with oxygen, dexamethasone, and terbutaline, but no improvement was seen. Surgical correction was performed using nine prosthetic tracheal ring implants. Clinical signs improved after surgery, and the cat continued to do well 11 months after surgery, despite development of unilateral laryngeal paralysis.  相似文献   

Wildlife diseases in New Zealand: recent findings and future challenges     

MR Alley  BD Gartrell 《New Zealand veterinary journal》2019,67(1):1-11

Our knowledge of diseases in New Zealand wildlife has expanded rapidly in the last two decades. Much of this is due to a greater awareness of disease as a cause of mortality in some of our highly threatened species or as a limiting factor to the successful captive rearing of intensely managed species such as hihi (Notiomystis cincta), kiwi (Apteryx spp.) and kakapo (Strigops habroptilus). An important factor contributing to the increase of our knowledge has been the development of new diagnostic techniques in the fields of molecular biology and immunohistochemistry, particularly for the diagnosis and epidemiology of viral and protozoan diseases. Although New Zealand remains free of serious exotic viruses there has been much work on understanding the taxonomy and epidemiology of local strains of avipox virus and circoviruses. Bacterial diseases such as salmonellosis, erysipelas and tuberculosis have also been closely investigated in wildlife and opportunist mycotic infections such as aspergillosis remain a major problem in many species. Nutritional diseases such as hyperplastic goitre due to iodine deficiency and metabolic bone disease due to Ca:P imbalance have made significant impacts on some captive reared birds, while lead poisoning is a problem in some localities. The increasing use of wildlife translocations to avoid the extinction of threatened species has highlighted the need for improved methods to assess the disease risks inherent in these operations and other intensive conservation management strategies such as creching young animals. We have also become more aware of the likelihood of inbreeding suppression as populations of many species decrease or pass through a genetic bottleneck. Climate change and habitat loss, however, remain the greatest threats to biodiversity and wildlife health worldwide. Temperature changes will affect our wildlife habitats, alter the distribution of disease vectors and wildlife predators, or directly harm threatened species in vulnerable localities.  相似文献   

Reconstructing past ocean pH-depth profiles   总被引：1，自引：0，他引：1  

MR Palmer  PN Pearson  SJ Cobb 《Science (New York, N.Y.)》1998,282(5393):1468-1471

Measurement of boron isotope compositions in species of planktonic foraminifera that calcified their tests at different depths in the water column are used to reconstruct the pH profile of the upper water column of the tropical ocean. Results for five time windows from the middle Miocene to the late Pleistocene indicate pH-depth profiles similar to that of the modern ocean in this area, which suggests that this method may greatly aid in our understanding of the global carbon cycle.  相似文献   

A comprehensive approach for assessing the economic contribution of forage and livestock improvement options to smallholder farming enterprises          下载免费PDF全文

Neil MacLeod  Scott Waldron  WEN Shi-lin 《农业科学学报》2015,14(8):1573-1580

The importance of livestock production activities to improving the livelihoods of smallholder farming households and the efficiency of their underlying farming systems is increasingly recognized.A rapid increase in livestock numbers, especially beef cattle, and special purpose forages is being promoted for smallholder farms which have traditionally undertaken subsistence cropping activities or simple livestock rearing activities using low quality feedstuffs.Because limited plantings of specialized forages combined with a poor knowledge of animal nutrition are a challenge to establishing sustainable livestock enterprises, much public policy and research is now being focused on the use of new forages and improved feeding practices.A number of economic studies have suggested that specialized forage growing and livestock feeding activities can make a positive contribution to smallholder welfare.The studies have typically compared the total level of farm or household income with and without livestock activities.Little attention is given to how much the new forage or livestock activities actually contribute to or draw resources from other farm activities to assess their real economic contribution to the enterprise, and the availability of simple tools to assist in making such assessments are limited.This paper describes a simple modelling approach that was developed for an Australian Centre for International Agricultural Research(ACIAR)-supported project to explore the real as opposed to apparent economic impact of integrating improved forages and livestock within smallholder farming systems in the Red Soils region of south-central China.Application of the model is demonstrated using a simple case study of a smallholder enterprise that plans to introduce a new beef cattle rearing activity to its existing farm activity mix.The case study highlights the importance of explicitly valuing transfers of resources between different farm activities to gauge the real contribution of those activities to economic returns.  相似文献   

The prediction of blood–tissue partitions,water–skin partitions and skin permeation for agrochemicals     

Michael H Abraham  Joelle MR Gola  Adam Ibrahim  William E Acree Jr  Xiangli Liu 《Pest management science》2014,70(7):1130-1137

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Heritability of juniper consumption in goats     

Waldron DF  Taylor CA  Walker JW  Campbell ES  Lupton CJ  Willingham TD  Landau SY 《Journal of animal science》2009,87(2):491-495

Data from goats (n = 505), collected over a 4-yr period, were used to estimate the heritability of juniper consumption. Juniper consumption was determined by near-infrared spectroscopy on fecal samples (n = 1,080) collected from female Boer-cross goats grazing pastures with a variety of plants, including juniper. The animals with records were progeny of 72 sires. Individual goats had from 1 to 4 observations over a 4-yr period. Predicted juniper consumption for individual observations ranged from -5 to +62% of the diet. Data were analyzed with a mixed model that included management group as a fixed effect, BW as a covariate, and permanent environment, animal, and residual as random effects. Management group was a significant source of variation. Least squares means of juniper consumption, as a percentage of the total intake, for management groups varied from 19 to 47%. Heritability of juniper consumption was 13%. Repeatability of juniper consumption was 31%. These results suggest that progress to selection for goats that will consume greater amounts of juniper is obtainable, but is expected to be slow.  相似文献   

Characterization of flavonoids and pectins from bergamot (Citrus bergamia Risso) peel, a major byproduct of essential oil extraction     

Mandalari G  Bennett RN  Bisignano G  Saija A  Dugo G  Lo Curto RB  Faulds CB  Waldron KW 《Journal of agricultural and food chemistry》2006,54(1):197-203

Bergamot peel is an underutilized byproduct of the essential oil and juice-processing industry. As with other Citrus peels, it still contains exploitable components, such as pectins and flavonoids. Commercial glycoside hydrolases, specifically a combination of pectolytic and cellulolytic enzymes, solubilized a high percentage of the material (81.94%). The flavonoid profile of the peel consisted of characteristic Citrus species flavanone rutinosides and neohesperosides derived from naringenin, eriodictyol, and hesperetin. In addition, a number of minor flavanone and flavone glycosides, not found in orange and lemon peels, were identified. The majority of flavonoids were extracted in the two 70% v/v EtOH extractions. Processing this material clearly has economic potential leading to low environmental impact.  相似文献   

E7 (1057ΔTA) mutation of the acidic α‐glucosidase gene causes Pompe's disease in Droughtmaster cattle          下载免费PDF全文

RE Lyons  DJ Johnston  MR McGowan  A Laing  B Robinson  H Owen  BD Hill  BM Burns 《Australian veterinary journal》2017,95(5):138-142

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