An integrated remote sensing and GIS approach in the monitoring and evaluation of rapid urban growth for sustainable development in the Pearl River Delta,China

The publication of the Brundtland Report in 1987 has led to worldwide concern over sustainable development. Sustainable development is particularly important to regions that are undergoing rapid economic development, such as the Pearl River Delta and other rapidly developing regions in China, Malaysia, Thailand and Asia. Geographical information systems (GIS) and remote sensing are useful tools in the formulation, implementation and monitoring of urban development in the move towards a sustainable development strategy. Since the adoption of economic reform in China in 1978, cities in the Pearl River Delta are developing very rapidly. Economic growth is around 20% a year, making it one of the highest growth areas in the world. Accompanying economic development is rapid urban growth. This paper attempts to demonstrate the application of the integration of GIS and remote sensing in urban growth management in the Pearl River Delta by using them to monitor and evaluate land development. Remote sensing techniques are used to carry out land‐use change detection by using multi‐temporal remote sensing data. Land‐use change impact analysis is further carried out by the integration of GIS and remote sensing.     

The sympathetic nervous system''s role in regulating blood pressurevariability

This article focuses on how sympathetic nerve activity (SNA) contributes to the variability seen in blood pressure. Specifically, it examines the following questions: why do oscillations occur at certain frequencies, why do only certain frequencies of oscillations in SNA induce oscillations in the vasculature, and what may be the functional purpose of these oscillations     

Conformational analysis of thiopeptides: free energy calculations on the effects of thio-substitutions on the conformational distributions of alanine dipeptides.

When the oxygen atom in a peptide bond is replaced by a sulfur atom, the restriction in the available conformational space and the ability of thioamides to confer resistance to enzymatic degradation renders thioamides as potentially useful building blocks for drug design and protein engineering. The solvation free energy differences between conformers of the same dipeptide can be high. Yet, previous conformational studies, basing on the (phi, psi) conformational energy maps of thio-substituted dipeptides, neglected both explicit water interactions and free energy considerations. In this paper, the (phi, psi) conformational free energy maps are obtained by single umbrella sampling in an explicit water environment for both alanine dipeptide and the corresponding thioamide derivatives. The phi and psi angles for the minima in the relative energy maps calculated with dielectric of 80 are similar to the corresponding phi and psi angles in the relative free energy maps for both Ac-Ala-NHMe (Ac: acetyl; Ala: alanine) and Act-Alat-NHMe (Act: thio-acetyl; Alat: thio-alanine). However, some large differences between the relative energy and relative free energy of major minima indicate that the consideration of free energy is important in determination of the relative occupancy of particular minima. Free energy maps for both Ac-Ala-NHMe and Act-Alat-NHMe show that thio-substitution favors conformations where phi < 0 because of the deeper beta and alphaR minima. The changes in the position and relative stability of minima were explained in terms of the destabilization of the regions near phi = -120, 0 and 120, psi = 60, -60, 180, which correspond to the increased steric hindrance due to the bulkier sulfur atom.     

The Epilog system-automated long-term EEG monitoring for epilepsy

Epilog, a Unix-based real-time operational support system for electroencephalogram (EEG) waveform acquisition, storage, analysis, display, and printing, is described. The system is designed to be used for diagnosis and surgical planning in a large epilepsy program. The implemented system has two monitoring units consisting of four rooms with their associated computer, video, and medical support systems. A central computer hub performs Epilog services for each unit. Each hub acquires and processes up to 256 channels of EEG 24 h per day, and serves as a control center for much of the automation in the unit. The EEG data structures and data flow used in Epilog are discussed.<>     

Laryngeal mucociliary clearance: influence of beta-2 agonists, beta antagonists, and alpha-agonists. An experimental study in rabbits

The high sensitivity but poor specificity of contrast enhanced magnetic resonance (MR) imaging for delineating malignant breast lesions is increasing the demand for MR guide breast biopsy. However, the poor patient access offered by conventional MR systems makes such procedures extremely difficult. We describe a method of performing breast biopsy outside the bore of the magnet using the 3-D MR imaging data. This involves a frameless stereotactic technique using an ultrasonic localizer. The position in space of the tip of a pointer with a handle which incorporates two ultrasound emitters can be tracked using an array of ultrasound detectors. MR visible marker beads (fiducials) placed on the breast and imaged at the same time are identified to the computer in relation to images of the breast. The ultrasonic localizer is used to register the position in space of the fiducials by touching them with the tip of the pointer. The image of the lesion within the breast can then be displayed in relation to the position of the tip of the pointer and the needle approach planned. Nine women with foci of enhancement on their dynamic contrast enhanced MR images underwent frameless stereotactic breast cytology. Needle placement within 2 mm of the lesion was achieved at first pass in eight out of nine (89%) cases: in one case the needle had to be re-positioned prior to sampling. This technique provides a means of targetting MR visible lesions using the MR imaging data whilst performing the procedure outside the magnet bore.     

Hyperhomocysteinemia induces elastolysis in minipig arteries: structural consequences, arterial site specificity and effect of captopril-hydrochlorothiazide

Hyperhomocysteinemia is a risk factor for arterial diseases, and the deterioration of the arterial elastic structures is one of the possible mechanisms underlying this epidemiological association. The aim of this paper is to quantitatively characterize such structural alterations and to explore their causes in a previous model of dietary induced mild hyperhomocysteinemia in minipigs. After four months, both a morphodensitometrical analysis of the elastic structure and a biochemical analysis of elastin and elastase activities were performed on the infrarenal abdominal aorta (IRAA) and the proximal left interventricular coronary artery (LIVCA) of control (C), hyperhomocysteinemic (H) and captopril-hydrochlorothiazide (Cp-Htz, 25 + 12.5 mg/d)-treated (H+/-Cp) minipigs (n = 8/group). Hyperhomocysteinemia was found to induce an increase in parietal elastolytic metalloproteinase activities. It resulted in opening and enlargement of fenestrae through the medial elastic laminae and in a decrease in medial elastin content (p < 10(-3)), expressed as well as volume density (%) as weight concentration (microg elastin/mg dry tissue). The thickness of the media and its basic lamellar organization was unchanged. The reduction in volume density was more dramatic in LIVCA (H: 4.7 +/- 0.9 vs C: 8.8 +/- 2.4), where it was evenly distributed within the media, than in IRAA (H: 6.7 +/- 1.1 vs C: 9.3 +/- 1.2), where the deep medial layers were less affected. Cp-Htz partly prevented the hyperhomocysteinemia-induced reduction of the medial elastin content in LIVCA (5.7 +/- 1.2) and IRAA (7.9 +/- 1.4). This effect, occurring in the subintimal layers of the media in both arteries but not in the deeper layers, resulted in a less beneficial effect in LIVCA than in IRAA. This result parallels the moderate beneficial therapeutic effect of ACE inhibitors against coronary atherosclerosis in humans. This paper reports for the first time a quantitative analysis of the arterial site-dependent deterioration of the elastic structure caused by mild hyperhomocysteinemia and the involvement of metalloproteinases in this process. These results confirm that the plaque-independent damage to elastic structure previously described in hyperhomocysteinemic-atherosclerotic minipigs was mainly due to homocysteine. This highlights that the metalloproteinase-related elastolysis and the subsequent structural deterioration is one of the major events underlying the epidemiological association between mild hyperhomocysteinemia and arterial diseases.     

CRACK GROWTH IN A TITANIUM ALUMINIDE ALLOY UNDER THERMAL MECHANICAL CYCLING

Abstract— The fatigue crack growth behavior in a titanium aluminide (Ti₃Al) alloy under thermo-mechanical loading as well as under elevated temperature conditions was investigated. The thermal mechanical fatigue crack growth behavior appears, in a general sense, to follow the same trends observed in similar data obtained in tests on nickel-base superalloys. However, crack growth in Ti₃Al appeared to be influenced by blunting of the crack tip due to creep in addition to a cyclic-dependent contribution together with time dependent or environmental enhanced degradation. This complex phenomenon in Ti₃Al is unlike that in nickel-base superalloys where crack growth was found to be due to a linear combination of cycle and time dependent contributions. Thus, the linear cumulative modelling technique is not applicable to the tested Ti₃Al.