Astrometry of circumstellar masers

The circumstellar masers around evolved stars offer an interesting possibility to measure stellar parameters through VLBI astrometry. In this paper the application of this technique is discussed, including the accuracy and the uncertainties of the method. The different maser species (OH, H_2O, SiO) have slightly different characteristics and applications. This paper does not concern astrometry of maser spots to study the kinematics of the envelope, but concentrates on attempting to measure the motion of the underlying star.Comment: 8 pages, 2 figures, to appear in "Mass-losing Stars and their Circumstellar Matter", eds Y. Nakada & M. Honma, Kluwer ASSL serie

3D modeling of 1612 MHz OH masers: Monte Carlo modeling of the maser shells and the amplified stellar image

We present the first results of our 3D Monte Carlo maser radiative transfer code, used to model the 1612 MHz OH maser shell and the amplification of emission from the stellar radio-photosphere.Comment: 2 pages, 1 figure; to be published in: Proceeding of WS on Mass-Losing Pulsating Stars and their Circumstellar Matter, Sendai, Japan, Y.Nakada & M.Honma (eds), Kluwer ASSL serie

The effect of genomic information on optimal contribution selection in livestock breeding programs

BACKGROUND: Long-term benefits in animal breeding programs require that increases in genetic merit be balanced with the need to maintain diversity (lost due to inbreeding). This can be achieved by using optimal contribution selection. The availability of high-density DNA marker information enables the incorporation of genomic data into optimal contribution selection but this raises the question about how this information affects the balance between genetic merit and diversity. METHODS: The effect of using genomic information in optimal contribution selection was examined based on simulated and real data on dairy bulls. We compared the genetic merit of selected animals at various levels of co-ancestry restrictions when using estimated breeding values based on parent average, genomic or progeny test information. Furthermore, we estimated the proportion of variation in estimated breeding values that is due to within-family differences. RESULTS: Optimal selection on genomic estimated breeding values increased genetic gain. Genetic merit was further increased using genomic rather than pedigree-based measures of co-ancestry under an inbreeding restriction policy. Using genomic instead of pedigree relationships to restrict inbreeding had a significant effect only when the population consisted of many large full-sib families; with a half-sib family structure, no difference was observed. In real data from dairy bulls, optimal contribution selection based on genomic estimated breeding values allowed for additional improvements in genetic merit at low to moderate inbreeding levels. Genomic estimated breeding values were more accurate and showed more within-family variation than parent average breeding values; for genomic estimated breeding values, 30 to 40% of the variation was due to within-family differences. Finally, there was no difference between constraining inbreeding via pedigree or genomic relationships in the real data. CONCLUSIONS: The use of genomic estimated breeding values increased genetic gain in optimal contribution selection. Genomic estimated breeding values were more accurate and showed more within-family variation, which led to higher genetic gains for the same restriction on inbreeding. Using genomic relationships to restrict inbreeding provided no additional gain, except in the case of very large full-sib families

From Nonstandard Analysis to various flavours of Computability Theory

As suggested by the title, it has recently become clear that theorems of Nonstandard Analysis (NSA) give rise to theorems in computability theory (no longer involving NSA). Now, the aforementioned discipline divides into classical and higher-order computability theory, where the former (resp. the latter) sub-discipline deals with objects of type zero and one (resp. of all types). The aforementioned results regarding NSA deal exclusively with the higher-order case; we show in this paper that theorems of NSA also give rise to theorems in classical computability theory by considering so-called textbook proofs.Comment: To appear in the proceedings of TAMC2017 (http://tamc2017.unibe.ch/

Factsheet verfproducten. Ten behoeve van de schatting van de risico's voor de consument. Geupdate versie voor ConsExpo 4

Voor de conversie van het computerprogramma ConsExpo 3 naar 4 is de factsheet verf aangepast en herzien en nu ook in het Engels beschikbaar. ConsExpo 4 is een computerprogramma, dat gebruikt kan worden om de blootstelling van mensen aan stoffen in consumentenproducten uit te rekenen. Hierbij wordt rekening gehouden met verschillende blootstellingroutes (dus via de huid, via inhalatie en via orale opname). Bij het ConsExpo programma hoort ook een database, waarin standaardwaarden voor vele product typen en voor een groot aantal blootstellingsscenarios worden aangeboden. De beschrijving van deze achtergrondinformatie bij deze standaardwaarden wordt gerapporteerd in zogenoemde 'factsheets'. In dit rapport, Factsheet verfproducten, is de meest recente informatie bijeengebracht om de blootstelling aan stoffen uit verfproducten te berekenen. De verschillende typen verfproducten zijn verdeeld in 7 categorieen, zoals het kwasten / rollen van verschillende soorten verf en het verspuiten van verf met een spuitbus en pneumatisch, met behulp van een compressor. Voor iedere categorie wordt de samenstelling en het gebruik van producten uit die categorie beschreven. Daarnaast wordt aangegeven welk model of modellen van ConsExpo het meest geschikt is om de blootstelling uit te rekenen en worden voor alle gegevens die nodig zijn voor de berekening, standaardwaarden ingevuld. Naast deze factsheet verfproducten zijn er ook factsheets voor ongediertebestrijdingsmiddelen, cosmetica, reinigingsmiddelen, doe-het-zelf producten en desinfectantia.Exposure to compounds in consumer products is assessed using the computer program ConsExpo (Consumer Exposure). Given the huge number of consumer products, it is not possible to calculate the exposure for each separate product, so a limited number of groups containing similar products are defined. The information for each group of products is described in a fact sheet. Pest control products, cosmetics and cleaning products are examples fact sheets, which have been published already. This fact sheet covers the use of paint products by consumers. In the fact sheet, 7 product categories are described, including brushing / rolling of several types of paint products and spraying paints with an aerosol spray can and pneumatic using a compressor. To assess exposure to compounds in paint products, default values for all 7 product categories have been determined.VW

The haematology of wild and laboratory acclimated Labeo umbratus (Teleostei; Cyprinidae)

The haematology of the mudfish (Labeo umbralus) has been studied in the laboratory and in the wild state. Significant differences between laboratory and field data and also between field data obtained for fish from different localities were observed in several of the parameters studied and the results are considered in relation to the validity of extrapolation of laboratory data to field conditions

Sequencing of ore columns for planning of large underground mines

This is the final version. Available from Wroclaw University of Science and Technology via the DOI in this record. Block caving is an underground mining technique which extracts ore from the base, rather than from the top, of typically massive deposits. Mining infrastructure is developed below the deposit before extraction commences. A network of tunnels provides access to a collection of drawpoints from which ore is mucked and hauled. With large deposits, not all drawpoints are developed simultaneously and the opening of drawpoints is sequenced to facilitate orderly extraction of ore columns above drawpoints. Sequencing fixes the initiation point for the entire block cave, or a part of it, as well as identifying the direction of cave advancement. The sequence of opening drawpoints influences the mine economics and is an integral aspect of planning a block cave mine. This paper discusses the optimisation of sequencing based on the net present value associated with extraction over the life-of-mine. It is shown that the maximum attainable net present value is obtained by a sequence in which ore columns are ranked in descending order of value. If significant variation of grade is present inside columns, an iterative procedure is given which corrects the sequence which yields the maximum net present value. The sequence with maximum net present value may not be practical or attractive from a caving perspective. Systematic design of sequences which permit orderly development of a block cave is discussed. To provide context, the net present value obtained from these feasible sequences is compared with the maximum attainable net present value. It is shown that the best feasible sequences in terms of net present value are preferentially initiated in zones with columns of high-grade ore.Rio Tinto Technical Services Lt

Sequencing of ore columns for planning of large underground mines

This is the final version. Available on open access from Wroclaw University of Science and Technology via the DOI in this recordBlock caving is an underground mining technique which extracts ore from the base, rather than from the top, of typically massive deposits. Mining infrastructure is developed below the deposit before extraction commences. A network of tunnels provides access to a collection of drawpoints from which ore is mucked and hauled. With large deposits, not all drawpoints are developed simultaneously and the opening of drawpoints is sequenced to facilitate orderly extraction of ore columns above drawpoints. Sequencing fixes the initiation point for the entire block cave, or a part of it, as well as identifying the direction of cave advancement. The sequence of opening drawpoints influences the mine economics and is an integral aspect of planning a block cave mine. This paper discusses the optimisation of sequencing based on the net present value associated with extraction over the life-of-mine. It is shown that the maximum attainable net present value is obtained by a sequence in which ore columns are ranked in descending order of value. If significant variation of grade is present inside columns, an iterative procedure is given which corrects the sequence which yields the maximum net present value. The sequence with maximum net present value may not be practical or attractive from a caving perspective. Systematic design of sequences which permit orderly development of a block cave is discussed. To provide context, the net present value obtained from these feasible sequences is compared with the maximum attainable net present value. It is shown that the best feasible sequences in terms of net present value are preferentially initiated in zones with columns of high-grade ore.Rio Tinto Technical Services Lt