Voracité comparative de trois coccinelles prédatrices contre le tétranyque rouge du pommier [Acarina : Tetranychidae]

La voracité de la coccinelle à sept points, Coccinella septempunctata, de la coccinelle à quatorze points, Propylea quatuordecimpunctata, et de la coccinelle orientale, Harmonia axyridis, [Coleoptera : Coccinellidae] a été évaluée en laboratoire face au tétranyque rouge du pommier, Panonychus ulmi [Acarina : Tetranychidae]. Les trois espèces ont consommé le tétranyque rouge. H. axyridis était significativement plus vorace que les autres espèces et présente le potentiel le plus élevé comme ennemi naturel du tétranyque. Malgré sa grande taille, C. septempunctata possédait une voracité très faible, ce qui confirme son inefficacité comme agent de lutte face aux acariens phytophages.Voracity of the seven-spotted ladybeetle, Coccinella septempunctata, the fourteen-spotted ladybeetle, Propylea quatuordecimpunctata, and the oriental ladybeetle, Harmonia axyridis [Coleoptera : Coccinellidae], was evaluated in laboratory on the European red mite, Panonychus ulmi [Acarina : Tetranychidae]. The three species fed on the European red mite. H. axyridis was significantly more voracious than the other species and has the greater potential as a natural enemy of the mite. Despite its large size, C. septempunctata showed a very low voracity, confirming its inefficacy as a biological control agent against phytophagous mites

Pathogenicity of Beauveria bassiana isolates toward Leptinotarsa decemlineata [Coleoptera : Chrysomelidae], Myzus persicae [Homoptera : Aphididae] and their predator Coleomegilla maculata lengi [Coleoptera : Coccinellidae]

L'effet pathogène de dix isolats de Beauveria bassiana de différentes sources et provenances géographiques a été évalué au laboratoire à une concentration de 107 conidies ml-1 sur deux insectes ravageurs, le doryphore de la pomme de terre ( Leptinotarsa decemlineata) et le puceron vert du pêcher ( Myzus persicae), et leur prédateur, la coccinelle maculée ( Coleomegilla maculata lengi). Six isolats ont provoqué une mortalité élevée sur les trois espèces d'insectes. Les quatre autres ont démontré un différent degré de spécificité pour les insectes visés. Les isolats 49, 233 et 210087 se sont avérés les plus intéressants comme agents de lutte biologique parce qu'ils ont démontré une forte virulence pour les insectes nuisibles mais ne causant qu'une faible mortalité pour la coccinelle.Ten isolates of Beauveria bassiana from different sources and geographical sites were evaluated under laboratory conditions at a concentration of 107 conidia ml-1 for their pathogenicity against two insect pests, the Colorado potato beetle (Leptinotarsa decemlineata) and the green peach aphid (Myzus persicae), and their predator, the spotted ladybird beetle (Coleomegilla maculata lengi). Six isolates were highly virulent to all three insect species. Four others showed different degrees of specificity. The isolates 49, 233 and 210087 were the most interesting for their potential development as biological control agents because they were highly virulent for the two insect pests and caused low mortality in the coccinellid

Biogeographic origin of the common green lacewings (Neuroptera, Chrysopidae) of the Azores archipelago, through morphology analysis

Due to a great dispersal ability and small size, insects are probably among the first island colonisers. Chrysoperla carnea sensu lato was for long considered the sole member of the Chrysopidae family in the Azores (Portugal) since it has been regarded as a complex of sibling species in Europe and North America. Its separation into different morphotypes is based on a set of pre-determined morphological traits. Their analysis leads to appraise Azorean Chrysopidae origin, comparing insular and mainland populations. Two outside “carnea complex” species, namely the Nearctic C. rufilabris and the Neotropical C. externa, were also examined to validate the method. Data analysis resulted in grouping separately the two out-group species as expected, and clearly joins insular and Palaearctic specimens of C. lucasina. Chrysoperla agilis, although known to be present in the Azores through courtship song analysis, is morphologically similar to the two other Palaearctic species, which confirms the continental Palaearctic origin of the common green lacewings in the Azores. Madeira has probably served as a stepping-stone to the Azorean colonisation

Evaluation des connaissances paysannes sur la diversité de l'entomofaune du sorgho et de l'arachide au Burkina Faso

Une enquête a été menée, de juillet à décembre 1996, dans cinq provinces productrices du sorgho et de l'arachide au Burkina Faso, pour évaluer les connaissances paysannes sur la diversité des insectes nuisibles aux deux cultures et sur leurs ennemis naturels associés. L'enquête a touché 244 personnes de cinq ethnies les plus représentées du pays. Les résultats montrent que les paysans du Burkina Faso ont une connaissance assez détaillée de la plupart des arthropodes nuisibles majeurs du sorgho et de I'arachide. En revanche, ils identifient certains arthropodes prédateurs, mais ils méconnaissent leur utilité dans la lutte contre les ravageurs des cultures. Pour protéger leurs productions, ils privilégient une lutte chimique sans précautions, au risque de s'intoxiquer et de polluer leur environnement. Il est donc nécessaire de les aider à différencier insectes nuisibles et ennemis naturels dans leurs champs, et à préserver ces derniers. (Résumé d'auteur

The influence of objectives, learning experiences and examination blueprint on medical students' examination preparation

BACKGROUND: The influence of intended and informal curricula on examination preparation has not been extensively studied. This study aims to firstly describe how students utilized components of intended and informal curricula to guide examination preparation, and secondly to study the relationship between examination preparation and performance. METHODS: Students received a pre-examination questionnaire to identify components from the intended curriculum (objectives and examination blueprint), and informal curriculum (content emphasised during lectures and small groups), used during examination preparation. Multiple logistic regression was used to study the relationship between these variables and student performance (above versus at or below average). RESULTS: Eighty-one students participated. There was no difference in the proportions using the examination blueprint, content emphasised during lectures, and content emphasised during small groups (87 – 93%) but fewer students used objectives (35%, p < 0.001). Objectives use was associated with reduced odds of above average examination performance (adjusted odds ratio 0.27 [0.07, 0.97], p = 0.04). CONCLUSION: When preparing for the renal course examination, students were influenced at least as much by the informal as the intended curriculum. Of the two intended curriculum components, the examination blueprint appeared to be more widely used than the course objectives. This decreased use of objectives on examination preparation did not appear to have a detrimental effect on student performance

The influence of objectives, learning experiences and examination blueprint on medical students' examination preparation

BACKGROUND: The influence of intended and informal curricula on examination preparation has not been extensively studied. This study aims to firstly describe how students utilized components of intended and informal curricula to guide examination preparation, and secondly to study the relationship between examination preparation and performance. METHODS: Students received a pre-examination questionnaire to identify components from the intended curriculum (objectives and examination blueprint), and informal curriculum (content emphasised during lectures and small groups), used during examination preparation. Multiple logistic regression was used to study the relationship between these variables and student performance (above versus at or below average). RESULTS: Eighty-one students participated. There was no difference in the proportions using the examination blueprint, content emphasised during lectures, and content emphasised during small groups (87 – 93%) but fewer students used objectives (35%, p < 0.001). Objectives use was associated with reduced odds of above average examination performance (adjusted odds ratio 0.27 [0.07, 0.97], p = 0.04). CONCLUSION: When preparing for the renal course examination, students were influenced at least as much by the informal as the intended curriculum. Of the two intended curriculum components, the examination blueprint appeared to be more widely used than the course objectives. This decreased use of objectives on examination preparation did not appear to have a detrimental effect on student performance

Boron microlocalization in oral mucosal tissue: implications for boron neutron capture therapy

Clinical studies of the treatment of glioma and cutaneous melanoma using boron neutron capture therapy (BNCT) are currently taking place in the USA, Europe and Japan. New BNCT clinical facilities are under construction in Finland, Sweden, England and California. The observation of transient acute effects in the oral mucosa of a number of glioma patients involved in the American clinical trials, suggests that radiation damage of the oral mucosa could be a potential complication in future BNCT clinical protocols, involving higher doses and larger irradiation field sizes. The present investigation is the first to use a high resolution surface analytical technique to relate the microdistribution of boron-10 (10B) in the oral mucosa to the biological effectiveness of the 10B(n,α)7Li neutron capture reaction in this tissue. The two boron delivery agents used clinically in Europe/Japan and the USA, borocaptate sodium (BSH) and p-boronophenylalanine (BPA), respectively, were evaluated using a rat ventral tongue model. 10B concentrations in various regions of the tongue mucosa were estimated using ion microscopy. In the epithelium, levels of 10B were appreciably lower after the administration of BSH than was the case after BPA. The epithelium:blood 10B partition ratios were 0.2:1 and 1:1 for BSH and BPA respectively. The 10B content of the lamina propria was higher than that measured in the epithelium for both BSH and BPA. The difference was most marked for BSH, where 10B levels were a factor of six higher in the lamina propria than in the epithelium. The concentration of 10B was also measured in blood vessel walls where relatively low levels of accumulation of BSH, as compared with BPA, was demonstrated in blood vessel endothelial cells and muscle. Vessel wall:blood 10B partition ratios were 0.3:1 and 0.9:1 for BSH and BPA respectively. Evaluation of tongue mucosal response (ulceration) to BNC irradiation indicated a considerably reduced radiation sensitivity using BSH as the boron delivery agent relative to BPA. The compound biological effectiveness (CBE) factor for BSH was estimated at 0.29 ± 0.02. This compares with a previously published CBE factor for BPA of 4.87 ± 0.16. It was concluded that variations in the microdistribution profile of 10B, using the two boron delivery agents, had a significant effect on the response of oral mucosa to BNC irradiation. From a clinical perspective, based on the findings of the present study, it is probable that potential radiation-induced oral mucositis will be restricted to BNCT protocols involving BPA. However, a thorough high resolution analysis of 10B microdistribution in human oral mucosal tissue, using a technique such as ion microscopy, is a prerequisite for the use of experimentally derived CBE factors in clinical BNCT. © 2000 Cancer Research Campaig

Uptake of the BPA into glioblastoma multiforme correlates with tumor cellularity

Fourteen patients scheduled to undergo craniotomy for glioblastoma multiforme were infused with p-boronophenylalanine fructose intravenously for 2 hours prior to surgery. Tissues removed during the procedure and blood obtained at its conclusion were analyzed for boron by direct current plasma-atomic emission spectroscopy. The results are presented herein

Boron neutron capture therapy of malignant brain tumors at the Brookhaven Medical Research Reactor

Boron neutron capture therapy (BNCT) is a bimodal form of radiation therapy for cancer. The first component of this treatment is the preferential localization of the stable isotope {sup 10}B in tumor cells by targeting with boronated compounds. The tumor and surrounding tissue is then irradiated with a neutron beam resulting in thermal neutron/{sup 10}B reactions ({sup 10}B(n,{alpha}){sup 7}Li) resulting in the production of localized high LET radiation from alpha and {sup 7}Li particles. These products of the neutron capture reaction are very damaging to cells, but of short range so that the majority of the ionizing energy released is microscopically confined to the vicinity of the boron-containing compound. In principal it should be possible with BNCT to selectively destroy small nests or even single cancer cells located within normal tissue. It follows that the major improvements in this form of radiation therapy are going to come largely from the development of boron compounds with greater tumor selectivity, although there will certainly be advances made in neutron beam quality as well as the possible development of alternative sources of neutron beams, particularly accelerator-based epithermal neutron beams