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Die Unterschiede in der Formaldehydabgabe zwischen mitteldichten Faserplatten werden durch Verlängerung der Prüfdauer in der WKI-Flaschenmethode besonders deutlich. Anhand der nach der WKI-Methode ermittelten Formaldehydabgabebeträge kann insofern zwischen Platten mit geringen Unterschieden in den Perforatorwerten deutlich differenziert werden. Die mit Hilfe der Jodometrie ermittelten Formaldehydabgabewerte liegen nur unwesentlich höher als die photometrisch bestimmten.

Two new types of air rifle pellet have been introduced; Prometheus, made from steel and nylon, and 'Sabo', made from lead alloy and plastic. Both have radio-opaque and radio-lucent components and their manufacturers claim better penetration. To establish their capabilities and the clinical implications a comparison of penetration was made between diablo, Prometheus and 'Sabo' pellets using gelatin 20% as a tissue simulant. Prometheus penetrated no further than diablo pellets but fragmented in up to 70% of cases. 'Sabo' penetrated 46% further than diablo (p = 0.001) and its plastic component did not penetrate at ranges greater than 0.5 m. Prometheus penetrated steel, unlike the other pellets, and is therefore potentially more dangerous in head injury. Because of fragmentation after impact it should be remembered that the radio-lucent sleeve is likely to be lying in the wound track. 'Sabo' would appear to be the most dangerous in soft and medium density materials.

Though the main theoretical concepts for the description of the formation and growth of the bubbles are the same as for clusters with a higher compared with the surrounding medium density the case of formation and growth of bubbles is investigated much less (see, e.g., WARD et al., 1982, 1984; KAGAN, 1960; RAO et al., 1978; SCHMELZER, SCHWEITZER, 1987a; BLANDER et al., 1971).

Mouse spleen cells have been fractionated into three subpopulations by density gradient centrifugation and the effect of interferon on the ability of each fraction to generate an antibody response in vitro has been examined. The results show that only the antibody-forming cell precursors (AFCP) of the high density, late responding fraction are suppressed by interferon. The presence of interferon had no effect on either the number or the mean size of clones of antibody-forming cells in cultures of the low and medium density fractions. Interferon-mediated suppression of the response of high density precursors was due to a decrease in the number but not the size of responding clones. These results suggest that interferon suppresses antibody responses by affecting the degree to which high density AFCP can becoming activated rather than the degree to which precursors proliferate.

Cattle have been invaluable for the transition of human society from nomadic hunter-gatherers to sedentary farming communities throughout much of Europe, Asia and Africa since the earliest domestication of cattle more than 10,000 years ago. Although current understanding of relationships among ancestral populations remains limited, domestication of cattle is thought to have occurred on two or three occasions, giving rise to the taurine (Bos taurus) and indicine (Bos indicus) species that share the aurochs (Bos primigenius) as common ancestor ~250,000 years ago. Indicine and taurine cattle were domesticated in the Indus Valley and Fertile Crescent, respectively; however, an additional domestication event for taurine in the Western Desert of Egypt has also been proposed. We analysed medium density Illumina Bovine SNP array (~54,000 loci) data across 3,196 individuals, representing 180 taurine and indicine populations to investigate population structure within and between populations, and domestication and demographic dynamics using approximate Bayesian computation (ABC). Comparative analyses between scenarios modelling two and three domestication events consistently favour a model with only two episodes and suggest that the additional genetic variation component usually detected in African taurine cattle may be explained by hybridization with local aurochs in Africa after the domestication of taurine cattle in the Fertile Crescent. African indicine cattle exhibit high levels of shared genetic variation with Asian indicine cattle due to their recent divergence and with African taurine cattle through relatively recent gene flow. Scenarios with unidirectional or bidirectional migratory events between European taurine and Asian indicine cattle are also plausible, although further studies are needed to disentangle the complex human-mediated dispersion patterns of domestic cattle. This study therefore helps to clarify the effect of past demographic history on the genetic variation of modern cattle, providing a basis for further analyses exploring alternative migratory routes for early domestic populations.

During the expression of recombinant proteins in the periplasm of Escherichia coli, the integrity of the outer membrane can change, so that product leaks to the medium. Additional stress can induce lysis, the complete disintegration of both inner and outer membrane, leading to release of both product and host cell proteins. Whether leakiness is unwanted or intentional, appropriate monitoring of leakiness and its distinction from lysis is necessary to ensure product quality and process performance. Here, we investigated a novel monitoring tool for leakiness and lysis based on the measurement of the culture supernatant density. The method benefits from short analysis time and low analytical error, simple result output, relatively low cost, low risk of operator errors and the option of easy on-line implementation. Although limitations exist regarding selectivity, we could show that the method is capable of detecting changes in cell integrity. This tool is therefore an interesting addition to the monitoring toolbox for industrial E. coli bioprocesses.

This study evaluated the effect of compression wood on dimensional stability of medium density fiberboards (MDF) manufactured from fiber furnishes of pine (Pinus nigra Arnold var. pallasiana) containing compression wood. Two panel types were manufactured from two different compression wood (CW) portion / normal wood (NW) portions in the furnish, 75/25 and 10/90, respectively. Linear and thickness variations of the panels exposed to various relative humidites at 20 °C, linear expansion/contraction and thickness swelling/shrinkage, were measured according to the procedures defined by DIN EN 318 (2005) standard test method. Panels made from fiber furnish containing 75% the CW had higher linear expansion and linear contraction values with an average value of 0.286% and 0.247% than those of panels made from fiber furnish containing 10% the CW with an average value of 0.184% and 0.152%, respectively. As for thickness swelling and thickness shrinkage properties, panels made from fiber furnish containing 75% the CW had the thickness swelling and thickness shrinkage values with an average of 5.042% and 4.402% while panels made from fiber furnish containing 10% the CW had the values with 3.621% and 2.861%, respectively. Consequently, based on the findings obtained from this study, expansion and swelling properties of the MDF panels were negatively affected by compression wood increase.

A long standing problem in the manufacture of wheat-straw based composites with cost-effective formaldehyde-based resins is their poor water resistance as demonstrated by their large water thickness swell. In this study, wheat straw based medium density fiberboards were manufactured using 3 resin/wax systems: a melamine-urea-formalde-hyde resin with either low or high wax content, and a phenol-formal-dehyde resin with low wax content. The flexural properties, internal bond strength, and thickness swell of the resulting composites were evaluated and compared according to ASTM methods. The three MDF compos-ites passed the requirements for MDF in interior application, except for the MDF manufactured with the aminoplastic resin and low wax content that failed to provide acceptable thickness swell. Using the phenolic resin in combination with low wax content resulted in a higher grade MDF composite, grade 120, than with the aminoplastic and high wax content. This study demonstrates that wheat straw based MDF manu-factured with cost-effective aminoplastic and phenolic resins can have flexural properties, internal bond strength and thickness swell perfor-mance above the requirements from the American National Standards Institute.

A series of load tests have been performed on instrumented 762mm diameter tubular steel piles driven into low to medium density Grade A/B chalk at St. Nicholas-at-Wade, Kent, United Kingdom. This paper presents the results from the static axial uplift tests, which were performed on two piles 7, 50 and 120 days after installation in order to investigate the time dependent variations in shaft resistance. The resultsshow that the static ultimate shaft resistance of this type of chalk can increase by up to a factor of seven over this time period, as a consequence of ‘set-up’ effects. The test results also show that the ‘set-up’ effect is reduced if the pile is subject to lateral loads up to 50% of the ultimate lateral capacity before uplift loading, whilst the application of lateral loading up to 10% of ultimate lateral capacity had negligible influence on the axial capacity. The measured load distribution from strain gauges suggests a mobilization of larger unit shaft resistance in the lower half of the pile. This paper also describes the geotechnical site conditions, the pile instrumentation and the effects of pile-driving on the chalk.

The effects of air-assisted delivery and spray volume on spray deposit characteristics, disease management and worker exposure were evaluated in a commercial vineyard using a crop with a characteristically light to medium density canopy. Neutron activation techniques were used to quantify amounts of fungicide on the leaf samples and on driver clothing. Spray quality characteristics were evaluated using a computer imaging system. Conventional applications were made using an air-assist sprayer with centrifugal fans. Ahooded sprayer was used to make non-airassisted applications at two application rates. The performance of the hooded sprayer treatments was equivalent to or superior to the conventional sprayer. Performance evaluations included quantification of foliar and clothing spray deposits, foliar spray coverage, and foliar disease ratings. Results indicate that under similar crop conditions, the hooded sprayer can reduce worker contamination and spray drift while providing equivalent control of vineyard diseases compared to the conventional, air-assist sprayer.

The aim of this study was to determine the influence of the application of glue, creating an elastic glue-line, on the deformation of wood-based panels asymmetrically veneered on one side with bamboo. The geometrical stability comparisons included multilayer composites used in the production of sliding doors, medium density fibreboard (MDF) panels, and chipboard used in the production of furniture. Chipboard panels retained their shape and stability after asymmetrical veneering, no matter which direction the veneer was placed in relation to the long edge. MDF boards retained their shape and stability only when they were veneered crosswise. The worst results were attained from composite boards, which bent in every case.

As is the case internationally, there is also an increased focus on urban space diversity in South Africa. Is it appropriate to pursue place diversity in South Africa? If so, what are the design factors that support place diversity and can these be accommodated by the development of medium density mixed housing in the country? Furthermore, could these emerging trends be considered as part of a larger global trend moving towards greater place diversity in cities, or does it only offer local fragments and practices of fashionable international ideas? This paper explores the multiple meanings of place diversity in the country as evident in the development of medium density mixed housing developments and highlights a number of paradoxes that emerge as a result of the context-specific realities.

The Steiner tree problem in graphs presents highest difficulties in case of graphs with a medium density of terminals. In fact, most of the efficient algorithms that have been developed to deal with the Steiner tree problem show their worse behaviour for a terminal density between 15 and 30%. Here we present a new bio-inspired approach based on a biological virus infection called viral system (VS) that emulates a massive infection in an organism (representing a massive exploration of the feasibility region). The approach is tested in a large-sized library of problems for which the optimal solution is known, and it is compared to other very efficient soft computing methodologies such as Tabu search and genetic algorithms that have been developed for this specific problem. The VS massive infection algorithm improves the results provided by such approaches.

Background Despite ongoing reductions in the cost of sequencing technologies, whole genome SNP genotype imputation is often used as an alternative for obtaining abundant SNP genotypes for genome wide association studies. Several existing genotype imputation methods can be efficient for this purpose, while achieving various levels of imputation accuracy. Recent empirical results have shown that the two-step imputation may improve accuracy by imputing the low density genotyped study animals to a medium density array first and then to the target density. We are interested in building a series of staircase arrays that lead the low density array to the high density array or even the whole genome, such that genotype imputation along these staircases can achieve the highest accuracy. Results For genotype imputation from a lower density to a higher density, we first show how to select untyped SNPs to construct a medium density array. Subsequently, we determine for each selected SNP those untyped SNPs to be imputed in the add-one two-step imputation, and lastly how the clusters of imputed genotype are pieced together as the final imputation result. We design extensive empirical experiments using several hundred sequenced and genotyped animals to demonstrate that our novel two-step piecemeal imputation always achieves an improvement compared to the one-step imputation by the state-of-the-art methods Beagle and FImpute. Using the two-step piecemeal imputation, we present some preliminary success on whole genome SNP genotype imputation for genotyped animals via a series of staircase arrays. Conclusions From a low SNP density to the whole genome, intermediate pseudo-arrays can be computationally constructed by selecting the most informative SNPs for untyped SNP genotype imputation. Such pseudo-array staircases are able to impute more accurately than the classic one-step imputation.

A study to compare two densities of plastazote used in the fabrication of insoles was undertaken. Parameters of durability, comfort and support were considered in 14 normal subjects. Statistical analysis demonstrated no significance between the mean difference in the initial and end thickness of the two materials, and the rate of thinning of the two materials. There was no correlation between body weight and the rate of thinning or the final thickness. After 12 weeks the mean thickness of the medium density plastazote was 1.59 mm. whereas in the low density the plastazote was .81 mm. Subjective parameters were measured by a questionnaire. The medium density was felt to offer support with questionable comfort. The low density provided comfort and support. In the clinical application it was suggested that for patients with sensitive areas on the plantar surface of the foot the comfortable low density material would be most appropriate. For patients with foot pain due mainly to arch strain the supportive more durable medium density would be best. A combination of the two materials has been suggested to provide comfort with increased durability.

International audience; Volatile acids (formic and acetic acid) from the surface and core layers of medium density fibre-boards (MDF) made from chemo-thermo-mechanical pulps (CTMP) were measured following the flask method technique. The results indicate explicitly that the emission of acids from the core layer is much higher than from the surface layer. The results are indicative of the influx of the steam distillable volatile acids from the surface layers to the core layer during pressing operation.

A study has been undertaken to obtain quantitative data on the energy outputs from vibratory plate compactors. Data have been obtained for four compactors of various sizes operating on a thick layer of Perth sand of medium density. It has been shown that the peak particle velocity measured near the surface is highly dependent upon the operating frequency of the machine and decays approximately in proportion to the inverse of the distance from the source. The transmitted vibration has been compared in terms of human and structural response with limits found in the literature. (Author/TRRL)

A new medium density barium suspension is described for the biphasic contrast examinations of the upper gastrointestinal tract. It is designed for the bubbly barium method, and combines good mucosal coating properties in the double contrast phase of the examination with transparency in the single contrast graded-compression phase.

A population of Microtus pennsylvanicus of high density, one of medium density, and one of low density were live-trapped in the summers of 1960 to 1962. Home ranges were calculated by several methods (minimum boundary, exclusive boundary, and inclusive boundary), and differences between the results of the three methods are presented. Individual ranges were determined by the number of different stations at which the vole was trapped. This method eliminates the factor of trap-habituation that appears when ranges are determined by the number of captures, and is conducive to better intra- and interspecific comparisons.

IN the course of a comprehensive study of the opaque mineral sands of New Zealand, the occurrence of thorium-containing minerals of medium density has been noted in the Westport area. Dr. C. O. Hutton, of Stanford University, California, has identified the principal minerals responsible as thorium-bearing sphene and the epidote allanite (private communication).