714 research outputs found
Pressure chamber explosion - Southern African Underwater and Hyperbaric Medical Association statement
The prevalence of the diagnosis of increased intra-ocular pressure in a general practice
Glaucoma is one of the main causes of blindness.1 The disease occurs in 3% to 4% of all people over the age of 70 years.1 As many as 50% of patients suffering from this disease are unaware of their condition until a comparatively late stage, due to the asymptomatic nature of the disease.2 Of the objective signs of primary open angle glaucoma, the loss of visual field and pathological cupping would generally have reached an advanced stage before they could be recognised by a general practitioner, and aqueous flow can only be measured with the use of specialised equipment. However, increased intra-ocular pressure can easily be detected by tonometry performed by a general practitioner.3For full text, click here:SA Fam Pract 2006;48(3):16-1
Strange Particle Production Via The Weak Interaction
The differential cross sections for the neutrino-induced weak charged current
production of strange particles in the threshold energy region are presented.
The general representation of the weak hadronic current is newly developed in
terms of eighteen unknown invariant amplitudes to parametrize the hadron
vertex. The Born term approximation is used for the numerical calculations in
the framework of the Cabibbo theory and SU(3) symmetry. For unpolarized octet
baryons four processes are investigated, whereas in the case of polarized
baryons only one process is chosen to study the sensitivity of the differential
cross section to the various polarizations of the initial state nucleon and the
final state hyperon.Comment: This paper was originally submitted to Physical Review C and
published on 30 August, 201
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The modulation of stationary waves, and their response to climate change, by parameterized orographic drag
The parameterization of orographic drag processes in atmospheric models remains uncertain due to a lack of observational and theoretical constraints on their formulation and free parameters. While previous studies have demonstrated that parameterized orographic drag acting near the surface has a significant impact on the atmospheric circulation, this work follows a more systematic approach to investigate its impacts on the large scale circulation and the circulation response to climate change. A set of experiments with a comprehensive atmospheric general circulation model is used to ascertain the range of climatological circulations that may arise from parameter uncertainty. It is found that the Northern Hemisphere (NH) wintertime stationary wave field is strongly damped over the North Pacific (NP) and amplified over the North Atlantic (NA) as a result of increased low-level parameterized orographic drag, both of which are shown to be conducive to higher-latitude westerlies. A comparison with the stationary wave field presented in other studies suggests that the too zonal NA jet and equatorward NP jet biases that are prevalent in climate models may be at least partly due to their representation of orographic drag. The amplitude of the stationary wave response to climate change across the experiments is shown to scale with the magnitude of low-level parameterized orographic drag through its influence on the present-day climatological stationary wave amplitudes over different sectors of the NH, which is consistent with linear stationary wave theory. This work highlights the importance of fidelity in a model's basic state for regional climate change projections
Effect of Pre-Planting Seed Treatment Options on Dormancy Breaking and Germination of \u3cem\u3eZiziphus Mucronata\u3c/em\u3e
Ziziphus mucronata (Buffalo thorn) is a multipurpose tree, widely adapted to a range of ecological conditions and tolerant of extreme climatic conditions, including frost and drought (Venter & Venter, 1996). It is a valuable fodder tree for livestock and game animals, especially in the drier parts of Africa (Rothauge et al. 2003). Similar to many other leguminous species, establishment is constrained by low and erratic germination of the seed, which has been attributed mainly to the physical barrier of the stony endocarp and dormancy associated with seed coat impermeability . This experiment aimed to compare the suitability of various seed treatment options as practical methods to break seed dormancy and enhance germination
Effect of Pre-Planting Seed Treatment Options on Dormancy Breaking and Germination of \u3ci\u3eZiziphus Mucronata\u3c/i\u3e
Ziziphus mucronata (Buffalo thorn) is a multipurpose tree, widely adapted to a range of ecological conditions and tolerant of extreme climatic conditions, including frost and drought (Venter & Venter, 1996). It is a valuable fodder tree for livestock and game animals, especially in the drier parts of Africa (Rothauge et al. 2003). Similar to many other leguminous species, establishment is constrained by low and erratic germination of the seed, which has been attributed mainly to the physical barrier of the stony endocarp and dormancy associated with seed coat impermeability. This experiment aimed to compare the suitability of various seed treatment options as practical methods to break seed dormancy and enhance germination
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Sensitivity of resolved and parameterized surface drag to changes in resolution and parameterization
The relative contribution of resolved and parameterized surface drag towards balancing the atmospheric angular momentum flux convergence (AMFC), and their sensitivity to horizontal resolution and parameterization, are investigated in an atmospheric model. This sensitivity can be difficult to elucidate in free-running climate models, in which the AMFC varies with changing climatologies and, as a result, the relative contributions of surface terms balancing the AMFC also vary. While the sensitivity question has previously been addressed using short-range forecasts, we demonstrate that a nudging framework is an effective method for constraining the AMFC. The Met Office Unified Model is integrated at three horizontal resolutions ranging from 130 km (N96) to 25 km (N512) while relaxing the model’s wind and temperature fields towards the ERAinterim reanalysis within the altitude regions of maximum AMFC. This method is validated against short range forecasts and good agreement is found. These experiments
are then used to assess the fidelity of the exchange between parameterized and resolved orographic torques with changes in horizontal resolution. Although the parameterized
orographic torque reduces substantially with increasing horizontal resolution, there is little change in resolved orographic torque over 20N to 50N. The tendencies produced
by the nudging routine indicate that the additional drag at lower horizontal resolution is excessive. When parameterized orographic blocking is removed at the coarsest of these resolutions, there is a lack of compensation, and even compensation of the opposite
sense, by the boundary layer and resolved torques which is particularly pronounced over 20N to 50N. This study demonstrates that there is strong sensitivity in the
behaviour of the resolved and parameterized surface drag over this region
Screening for childhood anaemia using copper sulphate densitometry
Objective. To evaluate copper sulphate densitometry to screen for childhood anaemia in a primary care setting, with a view to identifying children requiring definitive diagnostic testing and treatment.
Design. A cross-sectional screening study. Results of densitometry with a copper sulphate solution of specific gravity (SG) 1.048, corresponding to a haemoglobin (Hb) concentration of 10 g/dl, were compared with laboratory Hb determination.
Setting. Outpatient department of Pretoria Academic Hospital (73 children) and a local cr_che (27 children).
Subjects. One hundred consecutive children, aged between 6 months and 6 years, with informed written consent by parents.
Outcome measure(s). Accuracy of copper sulphate densitometry in screening for Hb concentration below 10 g/dl in terms of sensitivity, specificity, positive and negative predictive values, as well as likelihood ratio.
Results. The prevalence of anaemia (Hb < 10 g/dl) was 17% (95% confidence interval (CI) 10.2; 25.8). Copper sulphate densitometry had a sensitivity of 88.2% (95% CI 62.3; 97.9), a specificity of 89.2% (95% CI 79.9; 94.6), a positive predictive value of 62.5% (95% CI 40.8; 80.5) and a negative predictive value of 97.4% (95%CI 90.0; 99.5) in screening for anaemia. The likelihood ratio of a positive screening test was 8.17.
Conclusions. Copper sulphate densitometry was accurate in screening for childhood anaemia.
(South African Medical Journal: 2002 92(12): 978-981
Het gebruik van een drukplafond in een leghennenstal
In een kleine opstelling op 'Het Spelderholt' wordt het gebruik van een drukplafond bij leghennen uitgetest. Gekeken wordt naar de werking, de invloed op het klimaat en de praktische toepasbaarheid. Op grond van voorlopige resultaten kan nog geen definitief oordeel worden geveld
The Association between Primary Endometrioid Carcinoma of the Ovary and Synchronous Malignancy of the Endometrium
Objective. Ovarian and endometrial cancers coincide rather frequently in the same patient. Few data are available on the involvement of the specific morphological subtypes. To identify histological pathways in the synchronous occurrence, a population-based study was performed in The Netherlands. Methods. Using the national pathology database (PALGA) information of ovarian cancers and of earlier or later cancer in the endometrium was obtained. 5366 Patients were identified with primary malignant epithelial or borderline malignancy. Results. In 157 cases (2.9%) a new primary malignancy in the endometrium was diagnosed (146 within 1 year). The ratio of observed versus expected number of synchronous malignancy in the endometrium was estimated at 3.6 (95% CI: 2.7–4.7).
Among 460 ovarian endometrioid carcinoma patients 53 cases showed a second primary endometrial cancer; 40 out of these 53 cases (75.5%) showed at both organ sites an endometrioid adenocarcinoma. Conclusion. These findings suggest an important role for the endometrioid subtype and prompt to mechanism-based studies incorporating molecular techniques
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