Ultrasound-assisted regeneration of zeolite/water adsorption pair.

The use of ultrasound to enhance the regeneration of zeolite 13X for efficient utilization of thermal energy was investigated as a substitute to conventional heating methods. The effects of ultrasonic power and frequency on the desorption of water from zeolite 13X were analyzed to optimize the desorption efficiency. To determine and justify the effectiveness of incorporating ultrasound from an energy-savings point of view, an approach of constant overall input power of 20 or 25 W was adopted.

Protonation thermochemistry of selected hydroxy- and methoxycarbonyl molecules.

The gas-phase basicities of a representative set of hydroxy- and methoxycarbonyl compounds (hydroxyacetone, 1, 3-hydroxybutanone, 2, 3-hydroxy-3-methylbutanone, 3, 1-hydroxy-2-butanone, 4, 4-hydroxy-2-butanone, 5, 5-hydroxy-2-pentanone, 6, methoxyacetone, 7, 3-methoxy-2-butanone, 8, 4-methoxy-2-butanone, 9, and 5-methoxy-2-pentanone, 10) were experimentally determined by the equilibrium method using Fourier transform ion cyclotron resonance and high-pressure mass spectrometry techniques. The latter method allows the measurement of proton transfer equilibrium constants at various temperatures and thus the estimate of both the proton affinities and the protonation entropies of the relevant species. Quantum chemical calculations at the G3 and the B3LYP/6-311+G(3df,2p)//6-31G(d) levels of theory were undertaken in order to find the most stable structures of the neutrals 1-10 and their protonated forms.

Reassessing the level of unintended pregnancy and its correlates in Vietnam.

Despite rapidly increasing contraceptive use and rapidly declining fertility, unintended pregnancy and induced abortion remain common in Vietnam. This study reassesses the level of unintended pregnancy in Vietnam and its correlates, drawing on retrospective calendar data gathered for the Vietnam Demographic and Health Survey II. Data from 13,540 "segments" of outcomes and contraceptive practice were analyzed.

Maternal behavioural risk factors for severe childhood diarrhoeal disease in Kinshasa, Zaire.

This study examines the relationship between severe diarrhoeal disease and maternal knowledge and behaviours related to hygiene and sanitation. Some 107 paediatric cases admitted to two hospitals in Kinshasa, Zaire in 1988 were matched on age and nearest-neighbour status to 107 controls. Personal interviews and observational methods were used to assess knowledge and behaviours related to hygiene and sanitation.

Breast-feeding, water and sanitation, and childhood malnutrition in the Philippines.

This study examines effects and interactions of socioeconomic status, access to water supply and sanitation, and breast-feeding practices in relation to child growth in two provincial cities in the Philippines. Multivariate analysis identified food expenditure per head, education of the household head and gender of the child as significant predictors of nutritional status. The duration of partial and full breast-feeding was negatively (though non-significantly) associated with growth.

Development of information-based planning in Niger.

The authors present their experiences in assisting the government of Niger to develop automated information systems for health care management. They discuss the structure of the health system, the role of donor assistance, the process of initiating automated systems, and the technical requirements and costs of the system. Finally, they draw general conclusions that may be useful for those attempting similar efforts.

Conceptual framework for nutrition surveillance systems.

This article describes the evolution of nutrition surveillance as an intervention strategy and presents a framework for improving the usefulness of nutrition surveillance programs. It seems clear that such programs' impact on nutritional well-being will depend increasingly on their ability to reach and influence decision-makers. Therefore, it is important to consider political and social forces, and also to realize that if a program is too decentralized or too far removed from key decision-makers, its ability to influence resource flows may be limited.

Different guanosine triphosphate-binding proteins couple vasopressin receptor to phospholipase C and phospholipase A2 in glomerular mesangial cells.

To evaluate the identity of the guanosine triphosphate--binding proteins coupling arginine vasopressin receptor occupancy with activation of phospholipase C, leading to Ca2+ mobilization, and activation of phospholipase A2, leading to arachidonate release and prostanoid formation, we used intact cells, saponin-permeabilized cells, and membranes of the rat mesangial cell. Arginine vasopressin 10(-7) mol/L produced a dose-dependent increase in cytosolic Ca2+ to maximal levels of 500 nmol/L with peak responses occurring within 10 seconds of addition of arginine vasopressin to cells in suspension. Arginine vasopressin 10(-7) mol/L elicited a maximal response.

Composite indicators for famine early warning systems.

Traditional famine early warning systems use a host of indicators to predict food crisis situations, from rainfall and increased rate of marketing of household durables to the behavior of birds and animals. Although many of these indicators are valid in general, limited understanding of the sensitivity and specificity of the distress signals makes food crisis prediction a highly subjective exercise. In order to make the system more effective and credible, we need to identify a limited number of 'composite' indicators, which naturally summarize most relevant food-related information contained in the specific predictors of food crisis.

An intelligent computer-assisted instruction system designed for rural health workers in developing countries.

This paper describes an intelligent computer-assisted instruction system that was designed for rural health workers in developing countries. This system, called Consult-EAO, includes an expert module and a coaching module. The expert module, which is derived from the knowledge-based decision support system Tropicaid, covers most of medical practice in developing countries.

Regulation of mesangial cell cyclooxygenase synthesis by cytokines and glucocorticoids.

The cytokines, interleukin-1 (IL-1) and tumor necrosis factor (TNF), potently induce prostaglandin formation in glomerular mesangial cells. Mechanisms by which these cytokines stimulate prostaglandin formation vary among cell types. We investigated whether alterations in phospholipase A2 (PLA2) or cyclooxygenase (COX) mass and activity contribute to the changes in mesangial cell prostaglandin production.

Identification of a processed protein related to the human chaperonins (hsp 60) protein in mammalian kidney.

The chaperonin family of proteins, which includes GroEL protein of E. coli, yeast heat shock protein (hsp-60) and the ribulose-1-5-bisphosphate carboxylase (Rubis Co.) subunit binding protein of plant chloroplasts, shows strong sequence homology to the Chinese hamster ovary (CHO) mitochondrial P1 protein.

Dynamics of HIV infection and AIDS in central African cities.

A detailed stochastic model of HIV infection and AIDS for large cities in central Africa is described, which reproduces past events in Kinshasa, Zaire and projects rapid future spread of the disease, consistent with recent findings for Nairobi, Kenya. Most of the parameters used describe the behaviour of individuals, and it is therefore possible to look at the effects of changes in such behaviour, and thus to test various strategies aimed at providing effective public health policies. The model demonstrates that, if the spread of infection is to be controlled, changes in the behaviour of the major risk groups are essential.

A photoactivatable probe for the Na+/H+ exchanger cross-links a 66-kDa renal brush border membrane protein.

Earlier studies on LLC-PK1 cells have demonstrated two pharmacologically distinct Na+/H+ exchangers in renal epithelia. In addition, the cDNA clone for the human Na+/H+ antiporter which is growth factor activatable has been isolated and expressed (Sardet, C., Franchi, A.

Bradykinin stimulated PGE2 production is independent of changes in intracellular calcium in MDCK cells.

In order to assess whether changes in intracellular Ca2+ are necessary for bradykinin stimulated activation of phospholipase A2 and PGE2 production, MDCK cells were treated with phorbol myristate acetate (PMA) and Lanthanum (La3+). 100 nM PMA reduced peak BK (1 uM) stimulated Ca2+ to 44.0 +/- 11.

Differential correlates of nutritional status in Kinshasa, Zaire.

In an effort to search for causes of malnutrition in the urban environment to guide intervention efforts, a study of more than 2000 mother/child pairs was conducted in Kinshasa, Zaire. Under the auspices of the Zairian National Nutrition Planning Center a representative sample of a large lower class urban population was interviewed at two points in time. One phase covered morbidity and nutritional status measurements for all children under five years of age.

Protein kinase C modulates phospholipase C and increases arachidonic acid release in bradykinin stimulated MDCK cells.

The tumor promoter phorbol ester (PMA) has been shown to stimulate protein kinase C (PKC) in MDCK cells. At the concentrations that produce stimulation of PKC, PMA (100 microM) inhibits BK-induced I1,4,5P3 (IP3) formation and calcium transients in these cells. 1-5-isoquinolinyl-2-methyl-piperazine (H7) a known inhibitor of PKC in MDCK cells reverses the effect of PMA on BK-stimulated IP3 formation and Ca2+ transients in these cells.

Use of microcomputers in health and social service applications in developing nations.

The microcomputer is creating something of a revolution in many developing nations where historically there has been a lack of access to computer power at all levels of the health sector. For the first time, practitioners and researchers, often trained in computer techniques for developing countries, have access through microcomputers to data and information manipulation in their local workplace. While the history of microcomputers in such settings is short, this article presents early evidence from several countries which indicates the usefulness of various applications.

Microcomputer applications in health population surveys: experience and potential in developing countries.

Regrettably, because the content and technology are evolving so rapidly the literature on the application of microcomputer technology to health and development is either out of date, or hard to find (e.g. unpublished reports from consultants working with development agencies or universities).

Biorhythms revisited: rhythm and blues?

In a previous study, no significant relationship was seen between date of psychiatric admission or psychiatric emergency room visit and various phases or critical days in the biorhythm cycle. The present study evaluated these relationships for date of admission of 313 patients--192 with major depression, 88 with bipolar disorder, and 33 with schizophrenia or other diagnoses. No significant relationship to critical days or any combination of critical/noncritical days was found.

The impact of oedema on anthropometric measurements in nutritional surveys: a case study from Zaire.

Six surveys for protein-energy malnutrition were carried out in sequence in Bas-Zaire beginning at the end of 1978 at the estimated height of the famine and continuing throughout the recovery period. Utilizing a stratified multi-stage sampling technique, over 1000 children aged 6 months to 6 years were measured anthropometrically and examined for the presence or absence of bilateral pedal oedema in each survey. The proportions of children who were less than 80% of the reference median weight-for-height and who had oedema decreased, respectively, from 12.