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61.
The present paper describes a rapid assessment that was carried out in Cameroon from March to November 1994 and presents a summary of the findings and recommendations. It was the first rapid assessment study conducted by Cameroon in collaboration with the Economic Community of Central African States, with technical assistance from the World Health Organization and the support of the United Nations International Drug Control Programme. It was hoped that the study would help to fill gaps in the information available on drug abuser profiles, the types of drugs abused and the response of the community to drug abuse in Cameroon. In focus group discussions, key informant interviews and interviews with drug abusers, it was revealed that Cameroon was not only used by drug traffickers as a transit country, but was also a drug-consuming country. The drug consumers were both males and females from all age groups. The drugs consumed ranged from traditional drugs to imported cocaine and heroin. Cannabis was the most frequently consumed drug, followed by amphetamine-type tablets and a broad range of pharmaceuticals. Solvents were mainly consumed by street children in northern Cameroon. Local beer and gin also held a special place in society. In order to tackle the existing problems, programmes offering preventive education and alternative forms of recreation for youth were necessary, and national policies on demand and supply reduction should be harmonized.  相似文献   
62.
Previous studies have shown that the neutrophil-derived heparin-binding protein (HBP), also known as CAP37 or azurocidin, potentiates the LPS-induced release of proinflammatory cytokines (TNF-alpha, IL-1, and IL-6) from isolated human monocytes. To date, the mechanisms by which HBP enhances LPS-induced monocyte activation have not been elucidated, and it is not known whether HBP also increases the LPS-induced production of other bioactive substances. We studied human monocytes activated by recombinant human HBP and LPS and their interaction with the LPS receptor CD14. We hypothesized that the stimulatory effect of HBP on the LPS-induced release of proinflammatory mediators from monocytes was mediated by specific binding of HBP to monocytes, which resulted in an up-regulation of CD14. Our results demonstrated that HBP alone (10 microg/ml) stimulated the production of TNF-alpha from isolated monocytes. In addition, HBP had an additive effect on LPS-induced production of TNF-alpha and PGE2, suggesting a generalized monocyte activation. We used flow cytometry to demonstrate that HBP had a high affinity to monocytes but not to the LPS receptor CD14, and experiments performed at 4 degrees C indicated an energy-dependent step in this process. Confocal microscopy showed that monocytes internalize HBP within 30 min. These data suggest that mechanisms other than increased CD14 expression are responsible for the enhanced release of TNF-alpha or PGE2 in response to HBP and LPS.  相似文献   
63.
For nonruminants, stress and disease greatly increase requirements for vitamin B6, folic acid, pantothenic acid, and ascorbate. The effects of feed restriction, virus infection, and vitamin injections on plasma concentrations of B vitamins critical to the immune response were evaluated. Twelve beef steer calves, 6 to 8 mo of age, were fed below maintenance for 17 d and deprived of food for 3 d during a 20-d period after weaning. They then were inoculated intranasally with live attenuated bovine herpesvirus-1 (BHV-1). Six calves received saline injections and six received injections of a B vitamin mixture and ascorbate every 48 h for 14 d before and 14 d after inoculation. A mild respiratory infection developed in all calves 4 to 5 d after inoculation. In control calves, restricted intake and food deprivation decreased plasma vitamin B6 and pantothenate and increased vitamin B12 but did not affect folic acid and ascorbate concentrations. Vitamin injections increased plasma concentrations of vitamin B6, folic acid, vitamin B12, pantothenic acid, and ascorbate (P < .002). Plasma concentrations of vitamin B6, vitamin B12, pantothenic acid, and ascorbate, but not folic acid, were markedly reduced in all calves during the BHV-1 infection (P = .001). The vitamin B6, pantothenic acid, vitamin B12, and ascorbate status of stressed calves may affect their immune response to vaccination or infection.  相似文献   
64.
This study presents a focus group investigation of reasons why women in a rural, Sahelian community are reluctant to adopt family planning even when convenient services are made freely available. First, women opting to practice contraception must do so at considerable risk of social ostracism or familial conflict. Implementing individual preference is something that must be done without the support of others. Second, few women view personal decisions about contraceptives as theirs to make. Women and children are the property of the corporate family-kin and community militate against reproductive control. Third, although children are highly valued for a variety of economic, social, and cultural reasons, mortality risks remain extremely high. Low fertility imposes the unacceptable risk that a woman will have no surviving children at the end of her reproductive life. Taken together, these findings attest to the inadequacy of service strategies focused on the contribution of distribution, individual agency, or personal choice. Outreach should also build a sense of community legitimacy for the program, collective health action, and traditional leadership support for family planning behavior.  相似文献   
65.
A case of cavitary lung disease caused by Fusarium solani in a lung transplant recipient is presented. A mechanism for development of this infection is proposed. Lipid complex amphotericin B (Abelcet) was effective in eradicating this infection. To our knowledge, invasive lung disease caused by the Fusarium species has not been previously reported in a solid organ transplant recipient.  相似文献   
66.
67.
Broadband communication systems of the current generation are likely to offer higher bit rates for delivering high-speed multimedia services to the end users. The achievable capacity and data rate of wireless communication systems are limited to fading channels varying with time, leading to multiple access interference (MAI) and multipath interference (MPI). In this paper, we investigate downlink single-input multiple output transmission for complementary coded code-division multiple access (CC-CDMA) systems working in channels with multipath fading. Here, parallel interference cancellation is employed for analysis of CC-CDMA with different frequency domain equalization schemes to eliminate MPI and MAI over multipath fading channels. Error rate analysis for CC-CDMA employing receiver diversity is assessed using simulations under varying channel parameters. Further, we compare different equalization schemes to show the superiority of regularized zero forcing in reducing the error rate of CC-CDMA systems.  相似文献   
68.
ABSTRACT

Trioctyl phosphine oxide (TOPO) is examined as an extractant for phenol and other phenolic compounds. Equilibrium distribution coefficients have been measured for extraction of phenol, dihydroxybenzenes, and trihydroxybenzenes by solvents composed of TOPO in various diluents. Results are interpreted in terms of a model based upon complexation stoichiometry, allowing for solvation of uncomplexed solute as well. TOPO is a strong complexant for all the phenolic solutes studied. The nature of the diluent has a significant effect upon distribution coefficients, and in the case of an alcohol diluent reduces the distribution coefficient for phenol considerably.

The degree of complexation remains appreciable at temperatures which would be used for regeneration of phenol by distillation. This makes it necessary to use a diluent boiling at least 70°C to 80°C higher than the boiling point of phenol, which is 182°C. Regeneration studies are reported for isobutyl heptyl ketone, dimethyl naphthalene, and a mixture of dimethylnaphtahlaene and n-octadecane as diluents. Extraction with TOPO will be most worthy of consideration for feed concentrations of phenol equal to 3000 ppm or less, or for extraction of di- and trihydroxybenzenes.  相似文献   
69.
70.
Introduction to building projection-based tiled display systems   总被引:7,自引:0,他引:7  
This tutorial introduces the concepts and technologies needed to build projector-based display systems. Tiled displays offer scalability, high resolution, and large formats for various applications. Tiled displays are an emerging technology for constructing semi-immersive visualization environments capable of presenting high-resolution images from scientific simulation. The largest impact may well arise from using large-format tiled displays as one of possibly multiple displays in building information or active spaces that surround the user with diverse ways of interacting with data and multimedia information flows. These environments may prove the ultimate successor to the desktop metaphor for information technology work. Several fundamental technological problems must be addressed to make tiled displays practical. These include: the choice of screen materials and support structures; choice of projectors, projector supports, and optional fine positioners; techniques for integrating image tiles into a seamless whole; interface devices for interaction with applications; display generators and interfaces; and the display software environment  相似文献   
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