1,920 research outputs found

    Susceptibility to Phytophthora Cinnamomi of two Grapevine Rootstock Clones after Thermotherapy

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    The grapevine rootstocks 99 Richter clone I/30/1H74 infected with grapevine fleck and leafroll and 99 Richter Prosperi Super subclone 5 infected with stem pitting and leafroll were more susceptible to Phytophthora cinnamomi without treatment than after heat treatment to eliminate viruses. Recent field observations by various local workers (unpublished) and claims by local growers suggested that 99 Richer (Vitis berlandieri P. x V rupestris S.) grapevine rootstock material previously subjected to thermotherapy is more susceptible to Phytophthora cinnamomi Rands than untreated material. This contribution provides data on the effect of thermotherapy on the susceptibility of two 99 Richter rootstock clones to P. cinnamomi

    SALT Spectropolarimetry and Self-Consistent SED and Polarization Modeling of Blazars

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    We report on recent results from a target-of-opportunity program to obtain spectropolarimetry observations with the Southern African Large Telescope (SALT) on flaring gamma-ray blazars. SALT spectropolarimetry and contemporaneous multi-wavelength spectral energy distribution (SED) data are being modelled self-consistently with a leptonic single-zone model. Such modeling provides an accurate estimate of the degree of order of the magnetic field in the emission region and the thermal contributions (from the host galaxy and the accretion disk) to the SED, thus putting strong constraints on the physical parameters of the gamma-ray emitting region. For the specific case of the Îł\gamma-ray blazar 4C+01.02, we demonstrate that the combined SED and spectropolarimetry modeling constrains the mass of the central black hole in this blazar to MBH∌109 M⊙M_{\rm BH} \sim 10^9 \, M_{\odot}.Comment: Submitted to Galaxies - Proceedings of "Polarized Emission from Astrophysical Jets", Ierapetra, Crete, June 12 - 16, 201

    Dysbetalipoproteinaemia-clinical and pathophysiological features

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    Objectives. Dysbetalipoproteinaemia (type III hyperlipidaemia, broad-beta disease) is a highly atherogenic genetic disorder of lipoprotein metabolism. It presents with a severe mixed hyperlipidaemia in which the ratio of total cholesterol to triglycerides is typically 2:1. There is a high incidence of atherosclerotic complications and severe hypertriglyceridaemia may cause pancreatitis. Highly effective therapy is available and affected families also benefit from genetic counselling.We present a review of our experience with dysbetalipoproteinaemia at the lipid clinic of Groote Schuur Hospital to enhance awareness of this serious condition, for which the index of suspicion should be raised.Design. Retrospective review of case records, 1969- 2001.Setting. Lipid clinic of Groote Schuur Hospital, Cape Town.Subjects. Patients with dysbetalipoproteinaemia diagnosed by the presence of cholesterol-enriched very-low-density lipoproteins (VLDL) and/or dyslipidaemia associated with homozygosity for apolipoprotein E2 or carriers of the apoE2 (Arg 145 →Cys) mutation.Results. One hundred and five patients were identified, 55 of whom were male and 50 female. The age at presentation was 48.8 ± 11.1 years (mean, standard deviation). Total cholesterol was 12.0 ± 5.5 mmol/l and plasma triglycerides 8.3 ± 9.8 mmol/1. The ratio (by mass) of cholesterol to triglycerides within VLDL was 0.52 ± 0.17, while VLDL cholesterol to plasma triglycerides was 0.33 ± 0.09. Fifty patients were E2 homozygotes while 22 carried the apoE2(Arg→ 145 Cys) mutation. Palmar crease xanthomas occurred in 20% of patients, cutaneous xanthomas in 18%, and tendon xanthomas in 13%. Coronary artery disease was found in 47% of patients and peripheral vascular disease in 20%. Fibrates were the most commonly used hypolipidaemic agents (48%), while 31% of patients received combination therapy with a fibrate and statin. Statin monotherapy was used in 11% of patients and a few patients were treated with niacin or required no drug therapy. The treated cholesterol was 5.7 ± 2.4 mmol/1, with plasma triglycerides of 2.7 ± 1.9 mmol/1. Conclusions. Dysbetalipoproteinaemia is a highly atherogenic disorder and is extremely responsive to therapy. A significant proportion of dysbetalipoproteinaemia locally is caused by the apoE2(Arg→ 145 Cys) mutation and is therefore dominantly inherited. This mutation is particularly prevalent in the black community where dysbetalipoproteinaemia may be undiagnosed in many patients. Patients with severe mixed hyperlipidaemia or clinical stigmata of dyslipidaemia should be assessed at a lipid clinic for a specific diagnosis and initiation of therapy.

    Classification of White Cultivar Wines by Origin using Volatile Aroma Components

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    Stepwise discriminant analysis was applied to gas chromatographic data of some volatile compounds obtmiieabjiTreonextracliOii"of dry white table wines. By means of this statistical method, successful classifications according to origin of Colombar wines from two regions, and Chenin blanc wines from three regions, were obtained. The components with the highest discriminatory value were i-amyl acetate, hexyl acetate and i-butanol, in the case of the Colombar wines and hexanol and 2-phenyl ethanol in the case of the Chenin blanc wines

    Differentiation between Wines Originating from Different Red Wine Cultivars and Wine Regions by the Application of Stepwise Discriminant Analysis to Gas Chromatographic Data

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    Stepwise discriminant analysis (SDA) was applied to gas chromatographic data of some volatile compounds extracted with freon from red wines. By means of this statistical method, Pinotage and Cabernet Sauvignon wines (1978 vintage) could be classified into separate groups, the most effective variables being hexanol and i-amyl acetate. Pinotage wines from three, and Cabernet Sauvignon wines from two localities (1979 vintage) were subjected to classification according to origin. Successful classifications were obtained using the variables ethyl acetate, ethyl caprate, i-amyl acetate as well as a compound tentatively identified as i-valeric acid

    Objective quality rating of Pinotage wine

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    Relationships between wine composition and three quality parameters were investigated employing a linear multiple regression statistical model. For this purpose a least squares curve fitting computer programme was applied to analyses of 17 Pinotage wines for 6 fatty add esters. Overall quality, taste and aroma ratings were determined by a taste panel and utilized as dependent variables. lt was found that 2 esters viz. n-hexylacetate and ethyl-n-octanoate allowed excellent prediction equations to be set up for the quality ratings when incorporated into multiple regression equations.Objektive Beurteilung der WeinqualitĂ€t bei der Sorte PinotageDie Beziehungen zwischen der Weinzusammensetzung und drei Parametern der WeinqualitĂ€t wurden untersucht, wobei das statistische Modell einer mehrfachen linearen Regression verwendet wurde. Zu diesem Zweck wurden die bei 17 Weinen der Sorte Pinotage gewonnenen Analysenergebnisse ĂŒber 6 FettsĂ€ureester in ein Computerprogramm zur optimalen Kurvenanpassung eingegeben. Durch ein Gutachtergremium wurden die Gesamt-WeinqualitĂ€t, der Geschmack und der Geruch bewertet; die Daten dieser QualitĂ€tsbeurteilung wurden als abhĂ€ngige VerĂ€nderliche benĂŒtzt. Es wurde festgestellt, daß 2 Ester, nĂ€mlich n-Hexylacetat und Äthyl-n-octanoat eine ausgezeichnete Vorhersage der WeinqualitĂ€t ermöglichten, wenn ihre Werte in Mehrfachregressions-Gleichungen eingesetzt wurden

    Reproduction in the yellow mongoose revisited

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    Previous reports on female reproduction in yellow mongooses, based on anatomical examination of specimens, concluded that this species is monoestral but with an extended breeding period. Our long-term studies on known females provide clear evidence of the production of two litters annually within a period of 2-4 months, females initiating a new oestrus cycle while still lactating. We present a biological explanation for the adaptive significance of polyoestry in this species based on a unique mode of infant nutrition for viverrids

    Tuberculosis among older adults in Zambia: Burden and characteristics among a neglected group

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    BACKGROUND: The 2010 Global Burden of Disease estimates show that 57% of all TB deaths globally occurred among adults older than 50 years of age. Few studies document the TB burden among older adults in Southern Africa. We focused on adults older than 55 years to assess the relative TB burden and associated demographic factors. METHODS: A cross sectional nationally representative TB prevalence survey conducted of Zambian residents aged 15 years and above from 66 clusters across all the 10 provinces of Zambia. Evaluation included testing for TB as well as an in-depth questionnaire. We compared survey data for those aged 55 and older to those aged 15-54 years. Survey results were also compared with 2013 routinely collected programmatic notification data to generate future hypotheses regarding active and passive case finding. RESULTS: Among older adults with TB, 30/ 54 (55.6%) were male, 3/27 (11.1%) were HIV infected and 35/54 (64.8%) lived in rural areas. TB prevalence was higher in those aged ≄55 (0.7%) than in the 15-54 age group (0.5%). Males had higher rates of TB across both age groups with 0.7% (15-54) and 1.0% (≄55) compared with females 0.4% (15-54) and 0.6% (≄55). In rural areas, the prevalence of TB was significantly higher among older than younger adults (0.7% vs 0.3%), while the HIV infection rate was among TB patients was lower (11.1% vs 30.8%). The prevalence survey detected TB in 54/7484 (0.7%) of older adults compared to 3619/723,000 (0.5% ) reported in 2013 programmatic data. CONCLUSION: High TB rates among older adults in TB endemic areas justify consideration of active TB case finding and prevention strategies

    Spectral and stratigraphic mapping of hydrated sulfate and phyllosilicate-bearing deposits in northern Sinus Meridiani, Mars

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    We present detailed stratigraphic and spectral analyses that focus on a region in northern Sinus Meridiani located between 1°N to 5°N latitude and 3°W to 1°E longitude. Several stratigraphically distinct units are defined and mapped using morphologic expression, spectral properties, and superposition relationships. Previously unreported exposures of hydrated sulfates and Fe/Mg smectites are identified using MRO CRISM and MEX OMEGA near‐infrared (1.0 to 2.5 ”m) spectral reflectance observations. Layered deposits with monohydrated and polyhydrated sulfate spectral signatures that occur in association with a northeast‐southwest trending valley are reexamined using highresolution CRISM, HiRISE, and CTX images. Layers that are spectrally dominated by monohydrated and polyhydrated sulfates are intercalated. The observed compositional layering implies that multiple wetting events, brine recharge, or fluctuations in evaporation rate occurred. We infer that these hydrated sulfate‐bearing layers were unconformably deposited following the extensive erosion of preexisting layered sedimentary rocks and may postdate the formation of the sulfate‐ and hematite‐bearing unit analyzed by the MER Opportunity rover. Therefore, at least two episodes of deposition separated by an unconformity occurred. Fe/Mg phyllosilicates are detected in units that predate the sulfateand hematite‐bearing unit. The presence of Fe/Mg smectite in older units indicates that the relatively low pH formation conditions inferred for the younger sulfate‐ and hematitebearing unit are not representative of the aqueous geochemical environment that prevailed during the formation and alteration of earlier materials. Sedimentary deposits indicative of a complex aqueous history that evolved over time are preserved in Sinus Meridiani, Mars
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