922 resultados para MILD HYPOTHERMIA
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It is often debated whether migraine with aura (MA) and migraine without aura (MO) are etiologically distinct disorders. A previous study using latent class analysis (LCA) in Australian twins showed no evidence for separate subtypes of MO and MA. The aim of the present study was to replicate these results in a population of Dutch twins and their parents, siblings and partners (N = 10,144). Latent class analysis of International Headache Society (IHS)-based migraine symptoms resulted in the identification of 4 classes: a class of unaffected subjects (class 0), a mild form of nonmigrainous headache (class 1), a moderately severe type of migraine (class 2), typically without neurological symptoms or aura (8% reporting aura symptoms), and a severe type of migraine (class 3), typically with neurological symptoms, and aura symptoms in approximately half of the cases. Given the overlap of neurological symptoms and nonmutual exclusivity of aura symptoms, these results do not support the MO and MA subtypes as being etiologically distinct. The heritability in female twins of migraine based on LCA classification was estimated at .50 (95% confidence intervals [CI] .27 - .59), similar to IHS-based migraine diagnosis (h2 = .49, 95% CI .19-.57). However, using a dichotomous classification (affected-unaffected) decreased heritability for the IHS-based classification (h2 = .33, 95% CI .00-.60), but not the LCA-based classification (h2 = .51, 95% CI .23-.61). Importantly, use of the LCA-based classification increased the number of subjects classified as affected. The heritability of the screening question was similar to more detailed LCA and IHS classifications, suggesting that the screening procedure is an important determining factor in genetic studies of migraine.
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Latent class and genetic analyses were used to identify subgroups of migraine sufferers in a community sample of 6,265 Australian twins (55% female) aged 25-36 who had completed an interview based on International Headache Society (IHS) criteria. Consistent with prevalence rates from other population-based studies, 703 (20%) female and 250 (9%) male twins satisfied the IHS criteria for migraine without aura (MO), and of these, 432 (13%) female and 166 (6%) male twins satisfied the criteria for migraine with aura (MA) as indicated by visual symptoms. Latent class analysis (LCA) of IHS symptoms identified three major symptomatic classes, representing 1) a mild form of recurrent nonmigrainous headache, 2) a moderately severe form of migraine, typically without visual aura symptoms (although 40% of individuals in this class were positive for aura), and 3) a severe form of migraine typically with visual aura symptoms (although 24% of individuals were negative for aura). Using the LCA classification, many more individuals were considered affected to some degree than when using IHS criteria (35% vs. 13%). Furthermore, genetic model fitting indicated a greater genetic contribution to migraine using the LCA classification (heritability, h(2)=0.40; 95% CI, 0.29-0.46) compared with the IHS classification (h(2)=0.36; 95% CI, 0.22-0.42). Exploratory latent class modeling, fitting up to 10 classes, did not identify classes corresponding to either the IHS MO or MA classification. Our data indicate the existence of a continuum of severity, with MA more severe but not etiologically distinct from MO. In searching for predisposing genes, we should therefore expect to find some genes that may underlie all major recurrent headache subtypes, with modifying genetic or environmental factors that may lead to differential expression of the liability for migraine.
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Food poisoning is used to describe a range of illnesses caused by drinking or eating contaminated drink or food. Infectious pathogens include bacteria, viruses, parasites, or their toxins, though food poisoning can also be a result of eating poisonous plants e.g. some mushrooms, or animals e.g. puffer fish. Common symptoms include nausea, vomiting, watery diarrhoea, abdominal pain and cramps, and fevers, though these will vary depending on the causative pathogen or toxin. Symptoms can start within hours of eating contaminated food, or may begin days or weeks later. Most food poisoning is mild in nature, lasts for several hours to a few days, and generally resolves without treatment. However, some cases of food poisoning can also be extremely severe, with people requiring medical attention or admission to hospital...
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The studies presented in this thesis contribute to the understanding of evolutionary ecology of three major viruses threatening cultivated sweetpotato (Ipomoea batatas Lam) in East Africa: Sweet potato feathery mottle virus (SPFMV; genus Potyvirus; Potyviridae), Sweet potato chlorotic stunt virus (SPCSV; genus Crinivirus; Closteroviridae) and Sweet potato mild mottle virus (SPMMV; genus Ipomovirus; Potyviridae). The viruses were serologically detected and the positive results confirmed by RT-PCR and sequencing. SPFMV was detected in 24 wild plant species of family Convolvulacea (genera Ipomoea, Lepistemon and Hewittia), of which 19 species were new natural hosts for SPFMV. SPMMV and SPCSV were detected in wild plants belonging to 21 and 12 species (genera Ipomoea, Lepistemon and Hewittia), respectively, all of which were previously unknown to be natural hosts of these viruses. SPFMV was the most abundant virus being detected in 17% of the plants, while SPMMV and SPCSV were detected in 9.8% and 5.4% of the assessed plants, respectively. Wild plants in Uganda were infected with the East African (EA), common (C), and the ordinary (O) strains, or co-infected with the EA and the C strain of SPFMV. The viruses and virus-like diseases were more frequent in the eastern agro-ecological zone than the western and central zones, which contrasted with known incidences of these viruses in sweetpotato crops, except for northern zone where incidences were lowest in wild plants as in sweetpotato. The NIb/CP junction in SPMMV was determined experimentally which facilitated CP-based phylogenetic and evolutionary analyses of SPMMV. Isolates of all the three viruses from wild plants were genetically similar to those found in cultivated sweetpotatoes in East Africa. There was no evidence of host-driven population genetic structures suggesting frequent transmission of these viruses between their wild and cultivated hosts. The p22 RNA silencing suppressor-encoding sequence was absent in a few SPCSV isolates, but regardless of this, SPCSV isolates incited sweet potato virus disease (SPVD) in sweetpotato plants co-infected with SPFMV, indicating that p22 is redundant for synergism between SCSV and SPFMV. Molecular evolutionary analysis revealed that isolates of strain EA of SPFMV that is largely restricted geographically in East Africa experience frequent recombination in comparison to isolates of strain C that is globally distributed. Moreover, non-homologous recombination events between strains EA and C were rare, despite frequent co-infections of these strains in wild plants, suggesting purifying selection against non-homologous recombinants between these strains or that such recombinants are mostly not infectious. Recombination was detected also in the 5 - and 3 -proximal regions of the SPMMV genome providing the first evidence of recombination in genus Ipomovirus, but no recombination events were detected in the characterized genomic regions of SPCSV. Strong purifying selection was implicated on evolution of majority of amino acids of the proteins encoded by the analyzed genomic regions of SPFMV, SPMMV and SPCSV. However, positive selection was predicted on 17 amino acids distributed over the whole the coat protein (CP) in the globally distributed strain C, as compared to only 4 amino acids in the multifunctional CP N-terminus (CP-NT) of strain EA largely restricted geographically to East Africa. A few amino acid sites in the N-terminus of SPMMV P1, the p7 protein and RNA silencing suppressor proteins p22 and RNase3 of SPCSV were also submitted to positive selection. Positively selected amino acids may constitute ligand-binding domains that determine interactions with plant host and/or insect vector factors. The P1 proteinase of SPMMV (genus Ipomovirus) seems to respond to needs of adaptation, which was not observed with the helper component proteinase (HC-Pro) of SPMMV, although the HC-Pro is responsible for many important molecular interactions in genus Potyvirus. Because the centre of origin of cultivated sweetpotato is in the Americas from where the crop was dispersed to other continents in recent history (except for the Australasia and South Pacific region), it would be expected that identical viruses and their strains occur worldwide, presuming virus dispersal with the host. Apparently, this seems not to be the case with SPMMV, the strain EA of SPFMV and the strain EA of SPCSV that are largely geographically confined in East Africa where they are predominant and occur both in natural and agro-ecosystems. The geographical distribution of plant viruses is constrained more by virus-vector relations than by virus-host interactions, which in accordance of the wide range of natural host species and the geographical confinement to East Africa suggest that these viruses existed in East African wild plants before the introduction of sweetpotato. Subsequently, these studies provide compelling evidence that East Africa constitutes a cradle of SPFMV strain EA, SPCSV strain EA, and SPMMV. Therefore, sweet potato virus disease (SPVD) in East Africa may be one of the examples of damaging virus diseases resulting from exchange of viruses between introduced crops and indigenous wild plant species. Keywords: Convolvulaceae, East Africa, epidemiology, evolution, genetic variability, Ipomoea, recombination, SPCSV, SPFMV, SPMMV, selection pressure, sweetpotato, wild plant species Author s Address: Arthur K. Tugume, Department of Agricultural Sciences, Faculty of Agriculture and Forestry, University of Helsinki, Latokartanonkaari 7, P.O Box 27, FIN-00014, Helsinki, Finland. Email: tugume.arthur@helsinki.fi Author s Present Address: Arthur K. Tugume, Department of Botany, Faculty of Science, Makerere University, P.O. Box 7062, Kampala, Uganda. Email: aktugume@botany.mak.ac.ug, tugumeka@yahoo.com
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Hydrogen cyanide (HCN) is a toxic chemical that can potentially cause mild to severe reactions in animals when grazing forage sorghum. Developing technologies to monitor the level of HCN in the growing crop would benefit graziers, so that they can move cattle into paddocks with acceptable levels of HCN. In this study, we developed near-infrared spectroscopy (MRS) calibrations to estimate HCN in forage sorghum and hay. The full spectral NIRS range (400-2498 nm) was used as well as specific spectral ranges within the full spectral range, i.e., visible (400-750 nm), shortwave (800-1100 nm) and near-infrared (NIR) (1100-2498 nm). Using the full spectrum approach and partial least-squares (PLS), the calibration produced a coefficient of determination (R-2) = 0.838 and standard error of cross-validation (SECV) = 0.040%, while the validation set had a R-2 = 0.824 with a low standard error of prediction (SEP = 0.047%). When using a multiple linear regression (MLR) approach, the best model (NIR spectra) produced a R-2 = 0.847 and standard error of calibration (SEC) = 0.050% and a R-2 = 0.829 and SEP = 0.057% for the validation set. The MLR models built from these spectral regions all used nine wavelengths. Two specific wavelengths 2034 and 2458 nm were of interest, with the former associated with C=O carbonyl stretch and the latter associated with C-N-C stretching. The most accurate PLS and MLR models produced a ratio of standard error of prediction to standard deviation of 3.4 and 3.0, respectively, suggesting that the calibrations could be used for screening breeding material. The results indicated that it should be feasible to develop calibrations using PLS or MLR models for a number of users, including breeding programs to screen for genotypes with low HCN, as well as graziers to monitor crop status to help with grazing efficiency.
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Pimelea species (or desert riceflower) are small native plants endemic to the drier inland pastoral regions of Australia, which cause a unique syndrome in grazing cattle characterised by submandibular oedema and oedema in the brisket area as a result of right-sided heart failure attributed to the toxin simplexin. Field evidence suggests that poisoning can occur through minor, inadvertent consumption of Pimelea plant material, but the minimum simplexin intake required to induce Pimelea poisoning is not known. In this study, mild Pimelea poisoning was induced at a daily dose of 12.5 mg Pimelea/kg bodyweight per day, equivalent to 2.5 µg simplexin/kg bodyweight per day, demonstrating the high potential toxicity of these plant species. Effects in all animals diminished with prolonged low dose feeding and we postulate that these animals developed mechanisms for detoxifying simplexin, 1, possibly through rumen bacteria adaptation or activation of liver enzymes.
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The identification of "stay-green" in sorghum and its positive correlation with yield increases has encouraged attempts to incorporate "stay-green"-like traits into the genomes of other commercially important cereal crops. However, knowledge on the effects of "stay-green" expression on grain quality under extreme physiological stress is limited. This study examines impacts of "stay-green"-like expression on starch biosynthesis in barley (Hordeum vulgare L.) grain under mild, severe, and acute water stress conditions induced at anthesis. The proportions of long amylopectin branches and amylose branches in the grain of Flagship (a cultivar without "stay-green"-like characteristics) were higher at low water stress, suggesting that water stress affects starch biosynthesis in grain, probably due to early termination of grain fill. The changes in long branches can affect starch properties, such as the rates of enzymatic degradation, and hence its nutritional value. By contrast, grain from the "stay-green"-like cultivar (ND24260) did not show variation in starch molecular structure under the different water stress levels. The results indicate that the cultivar with "stay-green"-like traits has a greater potential to maintain starch biosynthesis and quality in grain during drought conditions, making the "stay-green"-like traits potentially useful in ensuring food security. (C) 2013 Elsevier Ltd. All rights reserved.
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The cholesterol side-chain cleavage enzyme activity is decreased considerably at the mild stage of vitamin A deficiency in rat testes and ovaries and the decrease in activity becomes more pronounced with progress of deficiency. Supplementation of the deficient rats with retinyl acetate, but not retinoic acid, restores the enzyme activity to normal values. The cholesterol side-chain cleavage enzyme of adrenals is not affected by any of the above treatments.
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Three ponies continuously grazed a pasture containing an estimated 24% Indigofera spicata (wet weight basis) for 4–6 weeks in April and May 2004. They developed ataxia, paresis, depression, muscle fasciculations, dysphagia, ptyalism and halitosis. Two also developed corneal opacity. One pony recovered with supportive treatment, but the other two were euthanased and necropsied. Neuropathology was not present in either case, but both livers had periacinar and periportal lymphocytic infiltrations and hydropic degeneration of mid-zonal hepatocytes, with mild to moderate periacinar necrosis also evident in one. The I. spicata contained 2.66 mg 3-nitropropionic acid (3-NPA)/g dry matter and 1.5 mg indospicine/g dry matter. Indospicine, but not 3-NPA, was detected in serum from both of the euthanased ponies and indospicine was detected in heart, liver and muscle from the one pony in which this assay was performed. The clinical syndrome closely resembled ‘Birdsville horse disease’ caused by I. linnaei and was similar to that reported in horses poisoned by the closely related species I. hendecaphylla and to 3-NPA poisoning of other animals, including humans. 3-NPA is thought to cause this neurological syndrome. To our knowledge, this is the first authenticated report of I. spicata poisoning in grazing animals. We also report here the first published evidence that 3-NPA and indospicine exist in naturalised I. spicata in Australia and of the formation of indospicine residues in tissues of animals grazing paddocks infested with I. spicata.
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Polyethene, polyacrylates and polymethyl acrylates are versatile materials that find wide variety of applications in several areas. Therefore, polymerization of ethene, acrylates and methacrylates has achieved a lot attention during past years. Numbers of metal catalysts have been introduced in order to control the polymerization and to produce tailored polymer structures. Herein an overview on the possible polymerization pathways for ethene, acrylates and methacrylates is presented. In this thesis iron(II) and cobalt(II) complexes bearing tri- and tetradentate nitrogen ligands were synthesized and studied in the polymerization of tertbutyl acrylate (tBA) and methyl methacrylate (MMA). Complexes are activated with methylaluminoxane (MAO) before they form active combinations for polymerization reactions. The effect of reaction conditions, i.e. monomer concentration, reaction time, temperature, MAO to metal ratio, on activity and polymer properties were investigated. The described polymerization system enables mild reaction conditions, the possibility to tailor molar mass of the produced polymers and provides good control over the polymerization. Moreover, the polymerization of MMA in the presence of iron(II) complex with tetradentate nitrogen ligands under conditions of atom transfer radical polymerization (ATRP) was studied. Several manganese(II) complexes were studied in the ethene polymerization with combinatorial methods and new active catalysts were found. These complexes were also studied in acrylate and methacrylate polymerizations after MAO activation and converted into the corresponding alkyl (methyl or benzyl) derivatives. Combinatorial methods were introduced to discover aluminum alkyl complexes for the polymerization of acrylates and methacrylates. Various combinations of aluminum alkyls and ligands, including phosphines, salicylaldimines and nitrogen donor ligands, were prepared in situ and utilized to initiate the polymerization of tBA. Phosphine ligands were found to be the most active and the polymerization MMA was studied with these active combinations. In addition, a plausible polymerization mechanism for MMA based on ESI-MS, 1H and 13C NMR is proposed.
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The use of ionic liquids in chemical research has gained considerable interest and activity in recent years. Due to their unique and varied physicochemical properties, in comparison to molecular solvents, the potential applications for ionic liquids are enormous. The use of microwave irradiation, as a powerful dielectric heating technique, in synthetic organic chemistry has been known since 1986. Since then, it has gained significant recognition for its research and application in both academia and industry. The use of either ionic liquids or microwave irradiation in synthetic organic chemistry has been known to afford improved, alternative or complimentary selectivities, in comparison to traditional processes. In this study, the use of ionic liquids as solvents, co-solvents and catalytic media was explored in Friedel-Crafts, deuterolabelling and O-demethylation reactions. Alternative methods for the production of a variety of aromatic ketones using the Friedel-Crafts acylation methodology were investigated using ionic liquid catalyst or ionic liquid acidic additive systems. The disclosed methods, i.e. metal bistriflamides and chloroindate ionic liquids systems, possessed good catalytic activity in the synthesis of typical benzophenones. These catalytic systems were also recyclable. Microwave irradiation was found to be useful in the synthesis of various polyhydroxydeoxybenzoins and arylpropanones as synthetic precursors to naturally occurring or potentially bioactive compounds. Under optimized condition, the reaction occurred in only four minutes using systems such as [bmim][NTf2]/HNTf2 and [bmim][BF4]/BF3·OEt2. Naturally occurring polyphenols, such as isoflavones, can possess various types of biological or pharmacological activity. In particular, some are noted for their beneficial effects on human health. Isotopically labelled analogues of polyphenols are valuable as analytical standards in the quantification of these compounds from biological matrices. A new strategy for deuterolabelling of polyphenols was developed using ionic liquids as co-solvents and 35% DCl/D2O, as a cheap deuterium source, under microwave irradiation. Under these conditions, perdeuterated compounds were achieved in short reaction times, in high isotopic purity and in excellent yields. An O-demethylation reaction was developed, using an ionic liquid reaction medium with BBr3 for the deprotection of a variety methyl protected polyphenolic compounds, such as isoflavons and lignans. This deprotection procedure was found to be very practical as the reaction occurred under mild reaction conditions and in short reaction times. The isolation and purification steps were particularly straightforward and high yielding, in comparison to traditional methods.
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Closed-form solutions are presented for approximate equations governing the pulsatile flow of blood through models of mild axisymmetric arterial stenosis, taking into account the effect of arterial distensibility. Results indicate the existence of back-flow regions and the phenomenon of flow-reversal in the cross-sections. The effects of pulsatility of flow and elasticity of vessel wall for arterial blood flow through stenosed vessels are determined.
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Astaxanthin is a powerful antioxidant with various health benefits such as prevention of age-related macular degeneration and improvement of the immune system, liver and heart function. To improve the post-harvesting stability of astaxanthin used in food, feed and nutraceutical industries, the biomass of the high astaxanthin producing alga Haematococcus pluvialis was dried by spray- or freeze-drying and under vacuum or air at − 20 °C to 37 °C for 20 weeks. Freeze-drying led to 41 higher astaxanthin recovery compared to commonly-used spray-drying. Low storage temperature (− 20 °C, 4 °C) and vacuum-packing also showed higher astaxanthin stability with as little as 12.3 ± 3.1 degradation during 20 weeks of storage. Cost-benefit analysis showed that freeze-drying followed by vacuum-packed storage at − 20 °C can generate AUD600 higher profit compared to spray-drying from 100 kg H. pluvialis powder. Therefore, freeze-drying can be suggested as a mild and more profitable method for ensuring longer shelf life of astaxanthin from H. pluvialis.
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The topic of this dissertation is the geometric and isometric theory of Banach spaces. This work is motivated by the known Banach-Mazur rotation problem, which asks whether each transitive separable Banach space is isometrically a Hilbert space. A Banach space X is said to be transitive if the isometry group of X acts transitively on the unit sphere of X. In fact, some weaker symmetry conditions than transitivity are studied in the dissertation. One such condition is an almost isometric version of transitivity. Another investigated condition is convex-transitivity, which requires that the closed convex hull of the orbit of any point of the unit sphere under the rotation group is the whole unit ball. Following the tradition developed around the rotation problem, some contemporary problems are studied. Namely, we attempt to characterize Hilbert spaces by using convex-transitivity together with the existence of a 1-dimensional bicontractive projection on the space, and some mild geometric assumptions. The convex-transitivity of some vector-valued function spaces is studied as well. The thesis also touches convex-transitivity of Banach lattices and resembling geometric cases.