Standard survey methods for estimating colony losses and explanatory risk factors in Apis mellifera

This chapter addresses survey methodology and questionnaire design for the collection of data pertaining to estimation of honey bee colony loss rates and identification of risk factors for colony loss. Sources of error in surveys are described. Advantages and disadvantages of different random and non-random sampling strategies and different modes of data collection are presented to enable the researcher to make an informed choice. We discuss survey and questionnaire methodology in some detail, for the purpose of raising awareness of issues to be considered during the survey design stage in order to minimise error and bias in the results. Aspects of survey design are illustrated using surveys in Scotland. Part of a standardized questionnaire is given as a further example, developed by the COLOSS working group for Monitoring and Diagnosis. Approaches to data analysis are described, focussing on estimation of loss rates. Dutch monitoring data from 2012 were used for an example of a statistical analysis with the public domain R software. We demonstrate the estimation of the overall proportion of losses and corresponding confidence interval using a quasi-binomial model to account for extra-binomial variation. We also illustrate generalized linear model fitting when incorporating a single risk factor, and derivation of relevant confidence intervals

Antibodies elicited in adults by a primary Plasmodium falciparum blood-stage infection recognize different epitopes compared with immune individuals

<p>Abstract</p> <p>Background</p> <p>Asexual stage antibody responses following initial <it>Plasmodium falciparum </it>infections in previously healthy adults may inform vaccine development, yet these have not been as intensively studied as they have in populations from malaria-endemic areas.</p> <p>Methods</p> <p>Serum samples were collected over a six-month period from twenty travellers having returned with falciparum malaria. Fourteen of these were malaria-naïve and six had a past history of one to two episodes of malaria. Antibodies to seven asexual stage <it>P. falciparum </it>antigens were measured by ELISA. Invasion inhibitory antibody responses to the 19kDa fragment of merozoite surface protein 1 (MSP1₁₉) were determined.</p> <p>Results</p> <p>Short-lived antibody responses were found in the majority of the subjects. While MSP1₁₉antibodies were most common, MSP1 block 2 antibodies were significantly less frequent and recognized conserved domains. Antibodies to MSP2 cross-reacted to the dimorphic allelic families and anti-MSP2 isotypes were not IgG3 skewed as shown previously. MSP1₁₉invasion inhibiting antibodies were present in 9/20 patients. A past history of malaria did not influence the frequency of these short-lived, functional antibodies (p = 0.2, 2-tailed Fisher's exact test).</p> <p>Conclusion</p> <p>Adults infected with <it>P. falciparum </it>for the first time, develop relatively short-lived immune responses that, in the case of MSP1₁₉, are functional. Antibodies to the polymorphic antigens studied were particularly directed to allelic family specific, non-repetitive and conserved determinants and were not IgG subclass skewed. These responses are substantially different to those found in malaria immune individuals.</p

The 10 kDa domain of human erythrocyte protein 4.1 binds the Plasmodium falciparum EBA-181 protein

BACKGROUND: Erythrocyte invasion by Plasmodium falciparum parasites represents a key mechanism during malaria pathogenesis. Erythrocyte binding antigen-181 (EBA-181) is an important invasion protein, which mediates a unique host cell entry pathway. A novel interaction between EBA-181 and human erythrocyte membrane protein 4.1 (4.1R) was recently demonstrated using phage display technology. In the current study, recombinant proteins were utilized to define and characterize the precise molecular interaction between the two proteins. METHODS: 4.1R structural domains (30, 16, 10 and 22 kDa domain) and the 4.1R binding region in EBA-181 were synthesized in specific Escherichia coli strains as recombinant proteins and purified using magnetic bead technology. Recombinant proteins were subsequently used in blot-overlay and histidine pull-down assays to determine the binding domain in 4.1R. RESULTS: Blot overlay and histidine pull-down experiments revealed specific interaction between the 10 kDa domain of 4.1R and EBA-181. Binding was concentration dependent as well as saturable and was abolished by heat denaturation of 4.1R. CONCLUSION: The interaction of EBA-181 with the highly conserved 10 kDa domain of 4.1R provides new insight into the molecular mechanisms utilized by P. falciparum during erythrocyte entry. The results highlight the potential multifunctional role of malaria invasion proteins, which may contribute to the success of the pathogenic stage of the parasite's life cycle

Identification of Rhoptry Trafficking Determinants and Evidence for a Novel Sorting Mechanism in the Malaria Parasite Plasmodium falciparum

The rhoptry of the malaria parasite Plasmodium falciparum is an unusual secretory organelle that is thought to be related to secretory lysosomes in higher eukaryotes. Rhoptries contain an extensive collection of proteins that participate in host cell invasion and in the formation of the parasitophorous vacuole, but little is known about sorting signals required for rhoptry protein targeting. Using green fluorescent protein chimeras and in vitro pull-down assays, we performed an analysis of the signals required for trafficking of the rhoptry protein RAP1. We provide evidence that RAP1 is escorted to the rhoptry via an interaction with the glycosylphosphatidyl inositol-anchored rhoptry protein RAMA. Once within the rhoptry, RAP1 contains distinct signals for localisation within a sub-compartment of the organelle and subsequent transfer to the parasitophorous vacuole after invasion. This is the first detailed description of rhoptry trafficking signals in Plasmodium

Varroa destructor [Anderson i Trueman, 2000]; zmiana w klasyfikacji w obrębie rodzaju Varroa [Oudemans, 1904]

Varroa jacobsoni was noted for the first time in 1904, in the nest of Apis cerana. In Apis mellifera nests the first Varroa mites were probably found in Korea (1950), next in Japan (1958). In the following years they have spread all over the world. All the time they were regarded as V. jacobsoni. Recently Anderson and Trueman have proved that Varroa jacobsoni is more than one species. They gave the new name Varroa destructor n. sp. to the group of six haplotypes. Mites, which became pests of A. mellifera worldwide, belong to V. destructor

Nosema ceranae [Eukaryota: Fungi: Microsporea] - a new parasite of Western honey bee Apis mellifera L.

Nosema ceranae was discovered in Apis cerana, Eastern honeybee first. Until recently A. cerana has been considered the only host to this parasite. A few years ago N. ceranae was recorded in honey bee Apis mellifera. It appeared that N. ceranae is more pathogenic for A. mellifera than Nosema apis. This parasite can cause significant losses in bee colonies. Bees die without symptoms observed in nosemosis caused by N. apis such as diarrhea

Assessment of gold with titanium alloy weldability in conditions of a dental technique laboratory

Purpose: In dental practice, there is necessary to weld gold with titanium under the conditions of a dental technique laboratory, which is difficult. The aim was to assess the weldability of pure gold with the titanium alloy Ti6Al4V using a prosthetic laser welding machine. Design/methodology/approach: Gold wire in a diameter of 0.4 mm made with the use of a jewellery drawbar (GOLDPORT, Szczecin, Poland) was welded to a titanium alloy Ti6Al4V substrate of dental implant abutment screw (MegaGen). Dental laser welding parameters (Bego Laser Star T plus) were 230 V; 6.5 ms; 2.5 Hz; laser spot 0.3 mm, and argon blow. Samples were included in resin, ground (500-4000 SiC), polished (Al2O3 suspension) and etched (Kroll solution) per 20 s before observation under a light microscope. Findings: There were well-welded and poorly joined zones. The discontinuities and voids there were not visible or sparse next to the initial weld point. Dendritic structure at well-welded remelting zones and two-phase microstructure of titanium and Ti3Au phase were found. The heat-affected zone was about of 20 microns. Research limitations/implications: Light microscopy was used, and precise phase identification required further investigations. Weld strength assessment requires further micro-hardness and load-bearing ability tests. Weldability concerns the model system with pure gold. Practical implications: In the case of elements with dimensions below 0.4 mm, the use of a laser with a smaller spot should be considered for better control of the remelting zone and mechanical positioning of the elements in order to stabilize and avoid discontinuities and voids. Originality/value: Prosthetic laser welding with a laser spot about of 0.3 mm allows to obtain well-welded parts of 0.3 mm in diameter under stable stitching conditions and higher than 0.4 mm in dimensions