Ecosystem change and human health: implementation economics and policy.

Several recent initiatives such as Planetary Health, EcoHealth and One Health claim that human health depends on flourishing natural ecosystems. However, little has been said about the operational and implementation challenges of health-oriented conservation actions on the ground. We contend that ecological-epidemiological research must be complemented by a form of implementation science that examines: (i) the links between specific conservation actions and the resulting ecological changes, and (ii) how this ecological change impacts human health and well-being, when human behaviours are considered. Drawing on the policy evaluation tradition in public economics, first, we present three examples of recent social science research on conservation interventions that affect human health. These examples are from low- and middle-income countries in the tropics and subtropics. Second, drawing on these examples, we present three propositions related to impact evaluation and non-market valuation that can help guide future multidisciplinary research on conservation and human health. Research guided by these propositions will allow stakeholders to determine how ecosystem-mediated strategies for health promotion compare with more conventional biomedical prevention and treatment strategies for safeguarding health.This article is part of the themed issue 'Conservation, biodiversity and infectious disease: scientific evidence and policy implications'.

The state of oral and dental health of the homeless and vagrant population of Montreal.

Not much is known about the state of oral and dental health of homeless and vagrant people in Montreal. However, a study conducted during April 1993, in conjunction with dental health month, has made it possible to undertake a better evaluation of their oral health status and to identify ways of making dental treatment available to them. Once the oral health status of this population is known, the official body responsible for homeless and vagrant individuals, the "Régie régionale Montréal-Centre," can be given possible solutions for their treatment and care. Most of the homeless are welfare recipients and have access to some basic benefits from this source. One of these benefits is free access to all assured basic dental services. These services are available after a six-month waiting period, and are provided by a dentist of the homeless person's choice. At the beginning of this study, the authors hypothesized that homeless people would prefer to be treated in the hostels and shelters where they sleep, which is currently the situation in Boston. But in 65 per cent of cases, their responses to a questionnaire administered as part of this study were quite different, and indicated that they would prefer to visit a private dentist of their choice. However, there is another important group (35 per cent) who wish to receive dental treatment in the hostels they presently frequent. Any proposed solution should take into consideration both groups of homeless and vagrant persons.

The teaching of geriatric dentistry in Canada.

Very little is known about the current status of geriatric training programs at Canadian universities because of the scarcity of information published on the subject. A study of the geriatric dentistry training programs offered by Canada's 10 dental schools has been completed. Its intent was to determine what type of educational activities in geriatric dentistry have either been offered in the past, are being offered now, will be offered in the next academic year, or are planned for the next five years. The results indicate that the 10 schools are doing very little in this regard. To keep pace with the level of geriatric dentistry training currently being offered in the United States, the dental profession must convince Canadian faculty members that the teaching of geriatric dentistry is crucial to both the undergraduate student and the graduate dentist. Continuing education in geriatric dentistry could be used to meet the oral health needs of our frail and dependent senior citizens. Geriatric dentistry must be taught at all levels of the profession so that this special clientele can receive the necessary treatment either within or outside of the dental office.

The tropical timber trade and sustainable development.

The tropical timber trade appears to have promoted neither sustained forest management nor sustained forest-based industrialization. The boom-and-bust export pattern is often blamed on demand by developed countries, high import barriers, and low international wood prices. In fact, it is rooted in tropical countries' own policies related to timber concessions and wood-processing industries. These policies suppress timber scarcity signals and must be revised if the trade is to promote sustained economic growth. Even if this is done, the trade may not promote sustained-yield forestry in individual countries.

Nucleotide sequence analysis of the genomes of the MAV-PS1 and P-PAV isolates of barley yellow dwarf virus.

The MAV-PS1 and P-PAV isolates of barley yellow dwarf virus (BYDV) are serologically related, but not identical. Both are transmitted by the aphid Macrosiphum avenae, but P-PAV is also transmitted by Rhopalosiphum padi. To evaluate the basis for these and other differences, overlapping clones from cDNA libraries representing the genome of each isolate were characterized by restriction enzyme digestion and by hybridization, and subsequently sequenced. Each genome has six positive strand open reading frames (ORFs) which are similar to those identified from a BYDV isolate from Australia (Vic-PAV). The greatest diversity between MAV-PS1 and P-PAV sequences was found in ORFs located in the 3' half of the respective genomes, in particular ORFs 5 and 6, suggesting that these regions of the genome may be involved in the properties that differentiate MAV-PS1 and P-PAV. Sequence comparisons between P-PAV and Vic-PAV showed a high degree of identity in that all ORFs showed greater than 90% amino acid similarity, except ORF6 which had only 69% similarity.

[Teaching of geriatric dentistry; training of "mobile dental service" dentists]. / L'enseignement de la dentisterie gériatrique; formation offerte aux chirurgiens dentistes du "service dentaire mobile".

Quebec presently has 650,000 people over 65 years of age and as many as 900,000 will be alive at the beginning of the 21st century. Quebec epidemiological studies have shown that this group's dental condition is very poor. They feel no need to see a dentist, but 96% of them need treatment and the time elapsed since their last dental visit averages 13 years. It is forecasted that the dental needs of this group will rise, not only because of their increase in number but also because they will retain more teeth. Training in geriatric dentistry is presently deficient in the United States, Canada and particularly Quebec. Researchers have concluded, after studying the U.S. dental schools' current status of geriatric dentistry educational activities, that unless dental students receive training in geriatrics while at dental school, it is likely that they will not treat a lot of seniors in their practice. The teaching of geriatric dentistry is in full swing in the U.S. but knows a difficult birth in Quebec. There is no formal, extensive training program in geriatric dentistry given by the three dental schools in the province. Practicing geriatric dentistry requires special knowledge and skills. If treatment is to be successful, the practitioner must adopt a humanitarian approach and develop close relations and a better understanding of the feelings and attitudes of the elderly. The dentist must know and understand the special dental problems that makes them different from other groups.

Nucleotide sequence analysis and genomic organization of the NY-RPV isolate of barley yellow dwarf virus.

cDNA clones representing the ssRNA genome of the NY-RPV isolate of barley yellow dwarf luteovirus (BYDV) were sequenced and 5600 nucleotides of the genome were determined. The deduced genome organization has limited similarity to that of another BYDV isolate, Vic-PAV, but is identical to that of beet western yellows (BWYV) and potato leafroll (PLRV) luteoviruses. NY-RPV has six major positive-sense open reading frames (ORFs) and, by comparison with RNA-dependent RNA polymerase and nucleic acid helicase consensus sequence motifs, it is postulated that NY-RPV ORF2 and ORF3 encode the viral replicase, which is expressed by a translational frameshift mechanism. The region of the NY-RPV genome containing the 22K coat protein ORF, the apparently associated internal apparent VPg ORF and the ORF immediately 3'-proximal (ORF6) to the coat protein ORF are organized as reported for other luteoviruses. Evidence is presented showing that ORF6 is expressed by readthrough of the coat protein gene termination codon, and that this protein is associated with the intact virus as a 65K protein. Although NY-RPV infects graminaceous rather than dicotyledonous plants, the taxonomic relationships between BYDV isolates and other luteoviruses deduced from the genome organization and sequence data strongly suggest that NY-RPV is distinct from the PAV-like isolates of BYDV and is more closely related to BWYV and PLRV.

[The "Mobile Dental Health Clinic of the South-West" (2)]. / La "Clinique mobile de santé dentaire du Sud-Ouest" (Deuxième partie).

The first part of the article entitled, "La Clinique mobile de santé dentaire du Sud-Ouest", reviewed the situation which was used to develop and organize the concept of a mobile dental service for seniors in nursing homes. In this article, we will detail how this can become a reality.

[The "Mobile Dental Health Clinic of the South-West" (1)]. / La "Clinique mobile de santé dentaire du Sud-Ouest" (Première partie).

One of the important mandates given to community health departments is to study and evaluate, in collaboration with other establishments, the organization and functioning of the territorial health services and, as a result, assure that everyone becomes part of the global picture of health and social service resources. It is for this specific reason that the Community Health Department of the Verdun Hospital Centre (DSC Verdun) dealt with the concept of accessibility to dental services for seniors living in nursing homes. We began by evaluating this clientele in order to verify the 1982 findings of researchers Simard, Brodeur, Kandelman and Lepage on the oral-dental health of Quebecers of 65 years of age and more. We found that in the territory around the DSC Verdun that the state of oral-dental health of the elderly living in nursing homes was quite deplorable and even worse than the average found throughout Quebec. Furthermore, we noticed the absence of dental clinics and services in almost all the establishments. Some elements of a solution will be reviewed in this article.

Nucleotide sequences of coat protein genes for three isolates of barley yellow dwarf virus and their relationships to other luteovirus coat protein sequences.

Barley yellow dwarf virus (BYDV) can be separated into two groups based on, among other criteria, serological relationships that are presumably governed by the viral capsid structure. Nucleotide sequences for the coding regions of coat proteins of approximately 22 K were identified for the MAV-PS1, P-PAV (group 1) and NY-RPV (group 2) isolates of BYDV. The MAV-PS1 and P-PAV coat protein sequences shared 71% deduced amino acid similarity whereas that of the NY-RPV isolate shared no more than 51% similarity with either the MAV-PS1 or the P-PAV sequence. Other comparisons showed that these and other BYDV coat protein sequences examined to date share a high degree of identity with those identified from other luteoviruses. Among luteovirus coat protein sequences in general, several highly conserved domains were identified whereas other domains differentiate MAV-PS1 and PAV isolates from NY-RPV and other luteoviruses. Sequence similarities and differences among BYDV coat proteins (approx. 22K) are consistent with the serological relationships exhibited by these viruses. Amino acid sequence comparisons between BYDV isolates that share common aphid vectors indicate that it is unlikely that these coat proteins are involved in aphid specificity.

[Toothbrush holder for a day-care center]. / Porte-brosses à dents hygiénique pour garderie.

A recent investigation of the various oral hygiene activities in 23 day-care centers located in the district administered by the Verdun Community Health Department has highlighted the need for a standardized hygienic method of storing toothbrushes. The study proposed to identify the main criteria related to hygiene that must be observed in order to prevent the transmission of contagious diseases within a day-care center, through the use of toothbrushes or toothbrush holders. Furthermore, the toothbrush holder has to meet four requirements: (1) be inexpensive; (2) be easy to build or manufacture; (3) allow the storage of 15 toothbrushes at the same time; (4) permit easy identification of the toothbrush by the child or teacher. A review of the literature, together with an assessment of toothbrush holders presently used by day-care centers in the district administered by the Verdun Community Health Department, showed that there were none which completely satisfied the required criteria. Under these circumstances, the authors of the study propose a detailed plan for the construction of a toothbrush holder that will satisfy these requirements. The toothbrush holder can be used to promote dental health to the very young. A sponsor could present it as a gift to one or more day-care centers in order to demonstrate their interest in the prevention of dental disease among these children.

Phytoalexin synthesis by the sorghum mesocotyl in response to infection by pathogenic and nonpathogenic fungi.

Infection of the sorghum mesocotyl by Helminthosporium maydis (a nonpathogen) and Colletotrichum graminicola (a pathogen) resulted in the rapid accumulation of a pigment complex by two sorghum cultivars. The components of the complex were fungitoxic. The principal compounds have been identified as the 3-deoxyanthocyanidins apigeninidin and luteolinidin. Apigeninidin accumulated in both sorghum cultivars in response to infection and was the predominant pigment. Luteolinidin accumulated in only one of the cultivars. Because of the speed of synthesis, occurrence only in response to inoculation, and fungitoxicity of the individual components, we propose that synthesis of the pigment complex constitutes a defense response and that the compounds apigeninidin and luteolinidin should be considered as phytoalexins.

Transfer of pRD1 to Pseudomonas syringae and evidence for its integration into the chromosome.

Plasmid pRD1 was conjugatively transferred from Escherichia coli to Pseudomonas syringae. Subculturing the transconjugate on a medium that selected for pRD1-determined His+ Kmr resulted in the loss of pRD1 as an extrachromosomal element as detected by agarose gel electrophoresis. DNA hybridization provided evidence for the integration of pRD1 into the P. syringae chromosome.