A study of the dynamic wetting behaviour of polyester tapes

The salient features of a study of the dynamic wetting behaviour of several polyester tapes are given, together with the complementary fluid and air entrainment phenomena. Analysis of the data shows that there is no significant difference between data from different tape surfaces and that a correlation between Weber and Reynolds number adequately describes the results. A practical empirical formula (r > 0.99) is given which relates the air entrainment velocity to fluid properties. This has the form: This formula agrees with experimental data for fluids with viscosity in the range 0.004 < μ <0.5 Nsm^?2 and surface tension in the range 0.025 < σ < 0.064 Jm^?2 whilst predicting the air entrainment velocity to within 10% of experimentally determined value.     

Transfer printing of DNA by "click" chemistry

This paper describes a straightforward procedure to immobilize oligonucleotides on glass substrates in well-defined micropatterns by microcontact printing with a dendrimer-modified stamp. The oligonucleotides are efficiently immobilized by "click" chemistry induced by microcontact printing. Acetylene-modified oligonucleotides were treated with an azide-terminated glass slide under the confinement of the dendrimer-modified stamp, without the use of a Cu(I) catalyst. The immobilization is an irreversible, covalent, and one-step reaction that results in stable attachment of the oligonucleotides. Oligonucleotides with the acetylene-modification at the 5' terminus hybridize selectively with full-length, complementary targets. Strands with more than one acetylene linker do not hybridize with complementary strands.     

A risk assessment of landscape hazards for building sites in the Front Range mountains of Colorado

Predictive spatial modelling is becoming an integral part of landscape planning. One emerging modelling approach is risk assessment. This paper illustrates the application of risk assessment techniques within a regional context for landscape planning and design, as urban development expands into mountainous building environments. The investigation examines the susceptibility of building sites in a portion of the Front Range mountains of Colorado/Wyoming to catastrophic disturbance by four landscape hazards: flooding, rockfall, fire and avalanche. A hazard rating model is applied to a portion of the Front Range, the Pingree Park vicinity, by employing geographic information system technology. We discovered that, below the tree-line, approximately 75% of the landscape contained a high risk rating and the remaining portion a moderate risk rating. This study implies that there is no long-term, safe building site in the study area. Assuming that the Pingree Park vicinity is a representative sample of the Front Range, our results would indicate that the long-term prospects for structures in the mountainous region of Colorado are not particularly promising; however, much more extensive study would be required before a definitive answer could be derived. Nevertheless, this investigation illustrates the basic principles and presents essential literature for landscape risk assessment planning.     

Structure-function studies on positions 17, 18, and 21 replacement analogues of glucagon: the importance of charged residues and salt bridges in glucagon biological activity

We have designed and synthesized eight compounds 2-9 which incorporate various amino acid residues in positions 17, 18, and 21 of the glucagon molecule: 2, [Lys17]glucagon amide; 3, [Lys18]glucagon amide; 4, [Nle17,Lys18,Glu21]glucagon amide; 5, [Orn17,18, Glu21]glucagon amide; 6, [d-Arg17]glucagon; 7, [d-Arg18]glucagon; 8, [d-Phe17]glucagon; and 9, [d-Phe18]glucagon. Compared to glucagon (IC50 = 1.5 nM), analogues 2-9 were found to have binding affinity IC50 values (in nM) of 0.7, 4.1, 1.0, 2.0, 5.0, 25.0, 43.0, and 32.0, respectively. When these compounds were tested for their ability to stimulate adenylate cyclase (AC) activity, they were found to be full or partial agonists having maximum stimulation values of 100, 100, 100, 100, 87, 78, 94, and 100%, respectively. On the basis of the X-ray crystal structure of [Lys17,18,Glu21]glucagon amide reported here, the ability to form a salt bridge between Lys18 and Glu21 is probably key to their increased binding and second messenger activities. Among the eight analogues synthesized here, only analogue 4 preserves the ability to form a salt bridge between Lys18 and Glu21. However, since these modifications are minor they do not seem to change the amphiphilic character of the C-terminus, allowing these analogues to reach 78-100% stimulation in the adenylate cyclase assay. Biological data from analogues 6-9 supports the idea that position 18 of glucagon may influence binding only, while position 17 may influence both receptor recognition and transduction.     

Molecular aspects of the synthesis and deposition of hens' egg yolk with special reference to low density lipoprotein

Avian egg yolk contains three main macromolecular constituents: 1) the yolk granules; insoluble particles consisting largely of lipovitellin and phosvitin. They are synthesized in response to hormones in the liver as a precursor protein, vitellogenin, which is soluble in blood. It passes through the oolemma by receptor-mediated endocytosis and is split up enzymically to give fragments that precipitate as granules in the yolk. 2) The livetins; essentially blood serum proteins. The mechanism for their transfer to yolk is not clear. 3) The yolk low density lipoprotein; the major part of yolk (60% of the dry weight). It is synthesized and assembled in the liver as a modified blood very low density lipoprotein, whose main apoprotein is apo B. As with vitellogenin, it enters yolk by endocytosis. Furthermore it is split enzymically to give most of the yolk-lipoprotein apoproteins (apovitellenins III to VI). New evidence for the relationship between yolk apoproteins and apo B has been derived from a comparison of the N-terminal amino acid sequences of apovitellenin IV and apo B.     

Denoising Deep Monte Carlo Renderings

We present a novel algorithm to denoise deep Monte Carlo renderings, in which pixels contain multiple colour values, each for a different range of depths. Deep images are a more expressive representation of the scene than conventional flat images. However, since each depth bin receives only a fraction of the flat pixel's samples, denoising the bins is harder due to the less accurate mean and variance estimates. Furthermore, deep images lack a regular structure in depth—the number of depth bins and their depth ranges vary across pixels. This prevents a straightforward application of patch‐based distance metrics frequently used to improve the robustness of existing denoising filters. We address these constraints by combining a flat image‐space non‐local means filter operating on pixel colours with a deep cross‐bilateral filter operating on auxiliary features (albedo, normal, etc.). Our approach significantly reduces noise in deep images while preserving their structure. To our best knowledge, our algorithm is the first to enable efficient deep‐compositing workflows with denoised Monte Carlo renderings. We demonstrate the performance of our filter on a range of scenes highlighting the challenges and advantages of denoising deep images.     

Deoxynivalenol: Rationale for development and application of a urinary biomarker

Mycotoxins are common dietary contaminants in most regions of the world. The frequency of exposure to the various families of mycotoxins is often dependent on geographic location, national wealth and related agricultural and regulatory infrastructure, combined with diversity of diet and degree of food sufficiency. Deoxynivalenol (DON) is a Fusarium mycotoxin that frequently contaminates wheat, corn and barley in temperate regions. A number of acute poisoning incidences have been linked to DON-contaminated foods and chronic exposure to lower levels of DON has been predicted in many regions. DON is a potent animal toxin and exposure in humans may cause gastroenteritis, growth faltering and immune toxicity. An ability to conduct accurate exposure assessment at the individual level is required to fully understand the potential health consequences for humans. To date, such exposure biomarkers have been lacking for many important mycotoxins, including DON. To better assess exposure to DON at the individual level, we have developed a robust urinary assay, incorporating immunoaffinity column (IAC) enrichment and LC–MS detection. Further refinement of this urinary assay, by inclusion of ¹³C-DON as an internal standard, was then undertaken and tested within the UK. DON was frequently observed in urine and was significantly associated with cereal intake. A dietary intervention study demonstrated that avoiding wheat in the diet markedly reduced urinary levels of DON. This biomarker requires further validation but our initial data suggest it may provide a useful tool in epidemiological investigations of the potential health consequences of this common environmental toxin.     

Formation of complexes between lecithin and apovitellenin I,an avian egg-yolk apoprotein

In a study of lipid-protein interactions in egg yolk, it was found that L-α-dipalmitoyl lecithin gave two distinct noncovalent complexes (A and B) with apovitellenin I, an apoprotein in the major yolk lipoprotein. Interaction took place under widely varied conditions, and yolk lecithin gave similar complexes. Complex A, which was formed within minutes, consisted of round particles of about 9 nm diameter. Complex B, which was formed more slowly, consisted of larger, particles. Possibly resembling curved discs, with diameter of 30–40 nm. The preparation and some properties of these complexes are described. It is suggested that they may be suitable for an extensive study of phospholipid-protein interactions in yolk.     

密歇根州旅游地的历史档案信息资源研究——以费耶特历史州立公园为例

以旅游为目的而研究历史景观的研究者们依赖于大量的档案、文献和私人收藏,从而收集到有关旅游地空间特征的众多信息,这些信息有助于旅游地游憩诠释及历史保护。在本研究中,我们的兴趣在于调查信息数量与完整性之间的关系,这些信息是密歇根州立档案馆为州属的机构(费耶特历史州立公园,由密歇根州立公园处所主管的机构)而收集的;同时,我们的兴趣还在于这些有关机构提供的信息资源的可利用程度。我们还对记录和报告等信息资源因何而被选为档案的过程感兴趣。我们发现当密歇根州有涉及州立机构的档案和收藏信息时,涉及场地的少量信息会被永久留存——主要是捐赠的照片和一些打印信件。相反,密歇根自然资源部州立公园处拥有广泛得多的业务资料,包括测绘的建筑图和旅游地平面图。此外,费耶特州立公园办公室还拥有由公园主管者每周完成的一份旅游地详细活动的报告。一些私人收藏因包含照片而很有价值,然而,密歇根自然资源部的资料以及私人收藏可能不会被永久存档。我们认为,涉及一个州的历史财产信息应该广泛传播,不应该被权力者独享。我们建议,州立档案馆只是以历史旅游地为目的的众多信息来源之一,研究者必须依靠个人的关系并持之以恒地去收集相应的信息。     

Mass-transfer Processes in Hank-dyeing Machines I—Theory and Experimental Studies

Meeting of the Midlands Region, held at the Carpet Trades Ltd Canteen, Kidderminster, on 13 February 1969, Mr D. O. Douglas in the chair The essential features of hank-dyeing machines are discussed in relation to the application of Fick's laws of diffusion to the mass-transfer processes occurring during dyeing. Dispersion equations and a mathematical model of the dyeing process are developed. The determination of dispersion coefficients on model hank systems is described. The results have been applied to the mathematical model using digital- and analogue-computer programs. The predictions of the computer-simulated dyeing process with respect to the distribution of dye within a hank are reasonably accurate in comparison with practical dyeings. The analogue-computer simulation of dyeing processes has general applicability beyond hank dyeing, provided that the appropriate system variables are known.