Response of Colombar Grapevines to Irrigation as Regards Quality Aspects and Growth

Plant response in terms of root, shoot and trunk growth as well as berry growth and composition, was determined in an irrigation trial with Colom bar comprising four soil moisture regimes, moisture stress during five phenological stages and four irrigation systems. All measurements were taken over a period of time to show parameter changes during variousstages within a season. A dry 25% soil moisture regime as well as trickle irrigation improved the sugar/acid ratio by lowering the malate and total titratable acid (TT A) concentrations and by increasing the total soluble solids (TSS) compared to soil moisture regimes of 50%, 70% and 90% which showed no significant differences with regard to either juice composition or berry size. Both the 25% moisture regime and water stress during flowering and phase I of berry growth were detrimental to berry size and yielded high tartrate concentrations at veraison. Tricklers and micro-jets at a 90% soil moisture regime yielded similar curves for cumulative berry growth. Root growth studied in situ reached maxima at flowering and in the post harvest period. The 25% soil moisture regime suppressed formation of new roots. Trunk circumference measured annually was a reliable indicator of vine water stress. Daily measurements of trunk radius with the aid of dendographs showed a maximum growth rate in November as well as an une.xpected negative rate from veraison until harvesting. A programme for regulated irrigation according to the growth patterns of the various plant parts is set forth. Suppression of undesirable shoot growth without a deleterious effect on berry growth, and acquisition of a more favourable grape composition seems possible

Canopy Temperature as a Water Stress Indicator in Vines

Canopy temperature (CT) of vine plots subjected to drying cycles, and of well-watered control plots was measured with the aid of an infra-red thermometer in a full-bearing Colombar vineyard together with measurements of leaf water potential (LWP) and stomata) resistance (Rs). A decrease in transpiration rate due to water stress caused plant temperature to rise above that of the non-stressed control. A maximum temperature difference of 3,2°C was obtained. The infra-red thermometer proved itself accurate and facilitated rapid temperature determinations while measurements of CT integrated temperatures of individual leaves. Canopy temperature was significantly and linearly correlated with soil water content (SWC). The study indicated that the onset of vine water stress occurred at plant available water contents of 30% - 50%, coinciding with a CT increase of 1,l6°C - 1,62°C above that of the control

Diurnal Variation in Grapevine Water Stress as a Function of Changing Soil Water Status and Meteorological Conditions

The response of the grapevine cultivar Colombar to three irrigation treatments viz., (1) a well-watered control (2) soil water depletion to 25% plant available water (PAW) and (3) wetting of only the upper 50% of the root zone, was investigated during the ripening stage. Diurnal fluctuations in leaf water potential (LWP), stomatal resistance (Rs) and photosynthetic activity (PA) were determined weekly and relationships with meteorological factors calculated. Water potential gradients existed between sunlit leaves, shaded leaves, bunches and soil. It is suggested that this is a driving force which creates water movement from bunches to leaves during daytime and from soil to bunches at night, thus explaining increased water use of vines with increased crop level. Diurnal changes in LWP and PA were best correlated with leaf temperature (r=0,95) and photosynthetic active radiation (r=O, 74) respectively. During daytime, stomata remained open until a threshold leaf water potential of -1600 kPa was reached. All plant parameters responded to increased water stress due to soil water depletion, but vines subjected to a reduction in the depth of wetting, showed no stress throughout the experiment. Pre-dawn LWP was the  most sensitive indicator of the onset of water stress which occurred at a soil water potential (SWP) of -64 kPa and a corresponding 42% PAW in the soil. Pre-dawn LWP correlated highly with SWP (r=0,95) and soil water content (r=0,89)

The Effect of Cover Crop Management on Soil Conditions and Weed 6ontrol in a Colombar Vineyard in Oudtshoorn

Wimmera and vetch were used as vineyard cover crops in the hot and dry Klein Karoo region. The effect of different masses of dry cover crop residues used as mulches, as well as that of a growing crop, on soil moisture conservation was compared with the effect of a "bare soil" treatment. Data obtained comrrmed the common notion that in vineyards under dry-warm conditions any growing plants other than vines removed water from the soil which should have been available to the vines. Accumulative water consumption over the whole season on the mulched plots was 50 mm less than the total of 530 mm on plots with a growing cover crop. The mulch played an important role in moisture conservation, especially in the early and critical growth phase of the vines. The higher moisture content on the mulched plots was determined not only in the top layers, but also down to a depth of 120 cm. Under these climatic conditions a crop factor of0,50 for vineyards with growing cover crops is suggested. The implications of growing a cover crop in dry areas for organic matter production, weed control and moisture conservation are discussed. It was concluded that biological weed control by means of mulches, produced by growing cover crops in the vineyard, can replace pre-emergence herbicides

Translated or culturally adapted audiology tests and questionnaires : balancing regional and international interests and resources

No abstract available.https://www.tandfonline.com/loi/iija20hj2023Speech-Language Pathology and Audiolog

A Search for Rapid Photometric Variability in Symbiotic Binaries

We report on our survey for rapid (time scale of minutes) photometric variability in symbiotic binaries. These binaries are becoming an increasingly important place to study accretion onto white dwarfs since they are candidate Type Ia supernovae progenitors. Unlike in most cataclysmic variables, the white dwarfs in symbiotics typically accrete from a wind, at rates greater than or equal to 10^{-9} solar masses per year. In order to elucidate the differences between symbiotics and other white dwarf accretors, as well as search for magnetism in symbiotic white dwarfs, we have studied 35 primarily northern symbiotic binaries via differential optical photometry. Our study is the most comprehensive to date of rapid variability in symbiotic binaries. We have found one magnetic accretor, Z And, previously reported by Sokoloski & Bildsten (1999). In four systems (EG And, BX Mon, CM Aql, and BF Cyg), some evidence for flickering at a low level (roughly 10 mmag) is seen for the first time. These detections are, however, marginal. For 25 systems, we place tight upper limits (order of mmag) on both aperiodic and periodic variability, highlighting a major difference between symbiotics and cataclysmic variables. The remaining five of the objects included in our sample (the 2 recurrent novae RS Oph and T CrB, plus CH Cyg, o Ceti, and MWC 560) had previous detections of large-amplitude optical flickering, and we present our extensive observations of these systems in a separate paper. We discuss the impact of our results on the ``standard'' picture of wind-fed accretion, and speculate on the possibility that in most symbiotics, light from quasi-steady nuclear burning on the surface of the white dwarf hides the fluctuating emission from accretion.Comment: 24 pages, 17 figures. Submitted to MNRAS (12/21/00), and revised in response to referee comments (3/30/01

The AeroCom evaluation and intercomparison of organic aerosol in global models

This paper evaluates the current status of global modeling of the organic aerosol (OA) in the troposphere and analyzes the differences between models as well as between models and observations. Thirty-one global chemistry transport models (CTMs) and general circulation models (GCMs) have participated in this intercomparison, in the framework of AeroCom phase II. The simulation of OA varies greatly between models in terms of the magnitude of primary emissions, secondary OA (SOA) formation, the number of OA species used (2 to 62), the complexity of OA parameterizations (gas-particle partitioning, chemical aging, multiphase chemistry, aerosol microphysics), and the OA physical, chemical and optical properties. The diversity of the global OA simulation results has increased since earlier AeroCom experiments, mainly due to the increasing complexity of the SOA parameterization in models, and the implementation of new, highly uncertain, OA sources. Diversity of over one order of magnitude exists in the modeled vertical distribution of OA concentrations that deserves a dedicated future study. Furthermore, although the OA / OC ratio depends on OA sources and atmospheric processing, and is important for model evaluation against OA and OC observations, it is resolved only by a few global models. The median global primary OA (POA) source strength is 56 Tg a−1 (range 34–144 Tg a−1) and the median SOA source strength (natural and anthropogenic) is 19 Tg a−1 (range 13–121 Tg a−1). Among the models that take into account the semi-volatile SOA nature, the median source is calculated to be 51 Tg a−1 (range 16–121 Tg a−1), much larger than the median value of the models that calculate SOA in a more simplistic way (19 Tg a−1; range 13–20 Tg a−1, with one model at 37 Tg a−1). The median atmospheric burden of OA is 1.4 Tg (24 models in the range of 0.6–2.0 Tg and 4 between 2.0 and 3.8 Tg), with a median OA lifetime of 5.4 days (range 3.8–9.6 days). In models that reported both OA and sulfate burdens, the median value of the OA/sulfate burden ratio is calculated to be 0.77; 13 models calculate a ratio lower than 1, and 9 models higher than 1. For 26 models that reported OA deposition fluxes, the median wet removal is 70 Tg a−1 (range 28–209 Tg a−1), which is on average 85% of the total OA deposition. Fine aerosol organic carbon (OC) and OA observations from continuous monitoring networks and individual field campaigns have been used for model evaluation. At urban locations, the model–observation comparison indicates missing knowledge on anthropogenic OA sources, both strength and seasonality. The combined model–measurements analysis suggests the existence of increased OA levels during summer due to biogenic SOA formation over large areas of the USA that can be of the same order of magnitude as the POA, even at urban locations, and contribute to the measured urban seasonal pattern. Global models are able to simulate the high secondary character of OA observed in the atmosphere as a result of SOA formation and POA aging, although the amount of OA present in the atmosphere remains largely underestimated, with a mean normalized bias (MNB) equal to −0.62 (−0.51) based on the comparison against OC (OA) urban data of all models at the surface, −0.15 (+0.51) when compared with remote measurements, and −0.30 for marine locations with OC data. The mean temporal correlations across all stations are low when compared with OC (OA) measurements: 0.47 (0.52) for urban stations, 0.39 (0.37) for remote stations, and 0.25 for marine stations with OC data. The combination of high (negative) MNB and higher correlation at urban stations when compared with the low MNB and lower correlation at remote sites suggests that knowledge about the processes that govern aerosol processing, transport and removal, on top of their sources, is important at the remote stations. There is no clear change in model skill with increasing model complexity with regard to OC or OA mass concentration. However, the complexity is needed in models in order to distinguish between anthropogenic and natural OA as needed for climate mitigation, and to calculate the impact of OA on climate accurately

Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.

BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362