Spatial Velocity Distributions in the Ascending Aorta of Healthy Humans and Cardiac Patients

Blood velocity profiles in the human ascending aorta were assessed with the aid of ultrasonic Doppler echocardiography. To this end, the transducer was placed in the suprasternal notch, and the spatial velocity profiles along an axis passing through the center of the aortic cross section were recorded by a multigate Doppler instrument. The profiles are analyzed with respect to characteristics independent of the angle of incidence and the cross sectional area. Data from 10 healthy individuals, 10 patients with hypertrophic obstructive cardiomyopathy (HOCM), and 10 patients with severe aortic insufficiency (AI) are compared. Five instantaneous profiles recorded at different times during systole and the temporal average of all profiles recorded during the entire cardiac cycle at 16 ms intervals are examined. Considerable differences between the three groups of subjects are observed visually as well as quantitatively in terms of specific parameters. The representation of the velocity maps in the form of contour graphs is particularly incisive. The results demonstrate that the temporal velocity patterns measured depend, in general, on both the disease and the location of the sampling volume within the aortic lumen. Reliable aortic volume flow rate measurements may have to be based on a method which takes into account the velocity at every point of the entire vascular cross section of patients with HOCM or AI.     

Decorin, biglycan and their endocytosis receptor in rat renal cortex

BACKGROUND: Among the small proteoglycans, biglycan and decorin have been proposed to be potent modulators of TGF-beta-mediated inflammatory kidney diseases. They were considered to become induced during glomerulonephritis and to subsequently inactivate the cytokine. METHODS: Decorin and biglycan as well as their endocytosis receptor were investigated in normal rat renal cortex, in anti-Thy-1 glomerulonephritis, in polycystic kidneys, in the remnant kidney following 5/6-nephrectomy, and in kidneys from the Milan normotensive strain by immunohistochemistry and in situ hybridization. Northern blots were used for the detection of mRNA expression for decorin and biglycan in isolated glomeruli. Functional aspects of the endocytosis of decorin and biglycan were studied in cultured mesangial cells. RESULTS: In the normal adult rat kidney decorin was expressed preferentially by Bowman's capsule and by interstitial connective tissue cells, but only in trace amounts by mesangial cells. In contrast, biglycan was found in tubular epithelial cells, in association with glomerular capillaries, podocytes and occasionally in the mesangium. In the tubulointerstitium of diseased kidneys (polycystic kidneys, 5/6-nephrectomy, kidneys from the Milan normotensive strain) there was a general up-regulation of decorin expression, while biglycan was localized only in distinct foci of fibrotic lesions. Glomerulosclerosis (5/6-nephrectomy, Milan normotensive strain) was associated with an increased staining for both decorin and biglycan within glomeruli. However, even in the anti-Thy-1 model of an acute mesangioproliferative glomerulonephritis where the greatest accumulation of decorin was found there was only a slight enhancement of decorin mRNA in isolated glomeruli. Decorin and biglycan become degraded upon receptor-mediated endocytosis. Immunohistochemical investigations indicated that the pattern of expression of the receptor protein correlated well with the immunolocalization of both decorin and biglycan. In vitro experiments with cultured mesangial cells provided direct evidence for the expression of the receptor and for the cell's capability to endocytose decorin as well as biglycan. CONCLUSIONS: Decorin and biglycan are characterized by a distinct expression pattern in the normal rat kidney, whereas the presence of their endocytosis receptor protein correlates with the expression of both proteoglycans. Decorin is almost completely absent in the normal mesangium. Both proteoglycans become up-regulated in various models of renal disease. The mesangial accumulation of decorin in the anti-Thy-1 glomerulonephritis that is observed in spite of the only slightly enhanced mRNA expression could result from decreased decorin turnover and/or increased mesangial retention.     

Calculation and comparison of the surface ionization ϕ(0)

An analytical expression for the surface ionization ?(O) is derived from fundamentals, viz., the ionization cross section and the angular and energy distribution of backscattered electrons. In order to avoid numerical integrations, a simple formula for the energy distribution of backscattered electrons is presented. The values given by the resulting expression for ?(O) are compared with those given by already known formulae and with experimental findings. In general, the agreement is quite satisfactory, although the calculated values generally are smaller than those experimentally found, especially at high overvoltages. This can at least partly be explained by secondary fluorescence excited by the continuous radiation, of which the correction has not been taken into account in the experimental determination of the ?(O) values.     

Semantic Based Greedy Levy Gradient Boosting Algorithm for Phishing Detection

The detection of phishing and legitimate websites is considered a great challenge for web service providers because the users of such websites are indistinguishable. Phishing websites also create traffic in the entire network. Another phishing issue is the broadening malware of the entire network, thus highlighting the demand for their detection while massive datasets (i.e., big data) are processed. Despite the application of boosting mechanisms in phishing detection, these methods are prone to significant errors in their output, specifically due to the combination of all website features in the training state. The upcoming big data system requires MapReduce, a popular parallel programming, to process massive datasets. To address these issues, a probabilistic latent semantic and greedy levy gradient boosting (PLS-GLGB) algorithm for website phishing detection using MapReduce is proposed. A feature selection-based model is provided using a probabilistic intersective latent semantic preprocessing model to minimize errors in website phishing detection. Here, the missing data in each URL are identified and discarded for further processing to ensure data quality. Subsequently, with the preprocessed features (URLs), feature vectors are updated by the greedy levy divergence gradient (model) that selects the optimal features in the URL and accurately detects the websites. Thus, greedy levy efficiently differentiates between phishing websites and legitimate websites. Experiments are conducted using one of the largest public corpora of a website phish tank dataset. Results show that the PLS-GLGB algorithm for website phishing detection outperforms state-of-the-art phishing detection methods. Significant amounts of phishing detection time and errors are also saved during the detection of website phishing.     

Changes in microstructures and physical properties of polymer-modified mortars during wet storage

The decrease in strength of tile adhesive mortars during wet storage was investigated. In a first approach, the water resistance of the polymer phases was tested on structures isolated from the mortar and in situ. It was observed that cellulose ether and polyvinyl alcohol structures are water-soluble. Subsequent investigations on polymer mobility within the mortar showed that the migrating pore water transports cellulose ether and polyvinyl alcohol during periods of water intrusion and drying. This leads to enrichments at the mortar-substrate interface. In contrast, latices interacting with the cement are water-resistant, and therefore, immobile in the mortar. Further experiments revealed that the mortar underwent considerable volume changes depending on the storage condition. Cracking occurred mainly close to the mortar-tile interface, cement hydrates grew within these shrinkage or expansion cracks. Test results revealed that the strength decrease of wet stored tile adhesives is caused by different mechanisms related to cement hydration, volume changes of the mortar, and reversible swelling of latex films.     

High surface area nanostructured tubes prepared by dissolution of ALD-coated electrospun fibers

Novel nanostructured and high surface area tubular materials were produced combining electrospinning and atomic layer deposition processes with the removal of polymeric template via dissolution. The dissolution process changed the structure of the tube walls, and the smooth atomic layer deposition coating was transformed into a highly complex, coral-like structure. This material, which we have called “nanocoral,” has a relatively high surface area, 323 m² g⁻¹, due to the interconnected cavities formed after the removal of the template. This kind of material has important potential applications, for example, in the fields of catalysts and filtration.     

Better or worse? The role of solar photovoltaic (PV) systems in sustainable development: Case studies of remote atoll communities in Kiribati

The Republic of Kiribati, formerly known as the Gilbert Islands, is a Micronesian (One of the three groups of islands in the Pacific. The eight territories that make up Micronesia are Commonwealth of the Northern Mariana Islands, Federated States of Micronesia, Republic of Kiribati, Republic of the Marshall Islands, Republic of Nauru, Republic of Palau, Territory of Guam and Territory of Wake Island. The other two groups of islands in the Pacific are Melanesia and Polynesia) country in the Pacific. The energy sources utilised in Kiribati include petroleum products, biomass, solar energy and wind power. Solar energy was introduced in Kiribati in the early 1980s (Wade H. Survey of RESCO projects – prepared for OPRET, Fiji Department of Energy, 2003; p. 36). Currently, it makes a very insignificant (less than 1%) contribution to the total annual primary energy supply (South Pacific Regional Environment Programme (SPREP). Pacific Islands Renewable Energy Project (PIREP) – Pacific Regional Energy Assessment (PREA) 2004. Kiribati national report, Vol. 5, 2005). Solar energy in Kiribati is used mostly in the form of solar photovoltaic (PV) technologies for the provision of lighting and electricity.This study examines the role of PV technologies in the sustainable development process in Kiribati, with particular reference to remote atoll communities. Initial results from on-site surveys carried out are reported in this paper. These surveys have sought to identify the reasons why people use or do not use PV systems.