An Experimental Investigation Into the Performance of a Flush Water-Jet Inlet

An experimental investigation of the flow within a generic flush type water-jet inlet has been carried out to identify the principal flow features and provide a basis for development of computational fluid dynamics (CFD) models. Tests were performed in a cavitation tunnel with the model inlet fitted to the test section ceiling, and effects of thickening the ingested tunnel wall boundary layer were investigated. The model was fitted with a range of instrumentation to investigate the ramp pressure distribution and boundary layer development, lip incidence, and pump face flow properties. Observations of lip and duct cavitation inception and behavior were also made. The results showed the inlet performance to be generally improved with the ingestion of a thicker boundary layer. The thickened boundary layer significantly reduced ramp boundary layer separation and distortion of flow at the notional pump face. However, a greater range of lip incidence occurred with the thickened boundary layer with consequent greater likelihood of lip separation and cavitation occurrence. Ideal lip incidence and pump face flow uniformity occurred at flow parameters significantly different from those for ideal pump face pressure recovery. Large developed cavities on the inlet lip were observed for a range of conditions typical of conventional high-speed vessel operation

Class Position of Immigrant Workers in a Post-Industrial Economy: The Dutch Case

In this paper, the issue of changing labour-market opportunities and the position of members of minority groups in advanced service economies is addressed, focusing on the Dutch case. We distinguish between two social hierarchies, one of traditional ‘fordist’ occupations and one of post-fordist occupations. Compared to the native Dutch, all immigrant groups are over-represented at the bottom of the labour market, both in the fordist and in the postindustrial hierarchy. Increased immigrant labour-market participation in the 1990s was accompanied by a strong rise in the number of flexible labour contracts. Native Dutch also work more frequently on flexible labour contracts, but not to the same extent as immigrants. The lower occupational level of the Surinamese, Antilleans and other non-Western immigrants employed in post-industrial occupations can be attributed to their low educational level. This is not true, however, for Turks, Moroccans and other non-Western immigrants employed in fordist occupations. Their low occupational level can not be completely explained by their low educational level. The effects of changes in the economic structure differ for ethnic groups, depending on their past employment, their cultural capital and the institutional framework in which they have to operate

Contribution of the epigenetic mark H3K27me3 to functional divergence after whole genome duplication in Arabidopsis

Background: Following gene duplication, retained paralogs undergo functional divergence, which is reflected in changes in DNA sequence and expression patterns. The extent of divergence is influenced by several factors, including protein function. We examine whether an epigenetic modification, trimethylation of histone H3 at lysine 27 (H3K27me3), could be a factor in the evolution of expression patterns after gene duplication. Whereas in animals this repressive mark for transcription is deposited on long regions of DNA, in plants its localization is gene-specific. Because of this and a well-annotated recent whole-genome duplication, Arabidopsis thaliana is uniquely suited for studying the potential association of H3K27me3 with the evolutionary fate of genes. Results: Paralogous pairs with H3K27me3 show the highest coding sequence divergence, which can be explained by their low expression levels. Interestingly, they also show the highest similarity in expression patterns and upstream regulatory regions, while paralogous pairs where only one gene is an H3K27me3 target show the highest divergence in expression patterns and upstream regulatory sequence. These trends in divergence of expression and upstream regions are especially pronounced for transcription factors. Conclusions: After duplication, a histone modification can be associated with a particular fate of paralogs: H3K27me3 is linked to lower expression divergence yet higher coding sequence divergence. Our results show that H3K27me3 constrains expression divergence after duplication. Moreover, its association with higher conservation of upstream regions provides a potential mechanism for the conserved H3K27me3 targeting of the paralogs

A probabilistic model for gene content evolution with duplication, loss, and horizontal transfer

We introduce a Markov model for the evolution of a gene family along a phylogeny. The model includes parameters for the rates of horizontal gene transfer, gene duplication, and gene loss, in addition to branch lengths in the phylogeny. The likelihood for the changes in the size of a gene family across different organisms can be calculated in O(N+hM^2) time and O(N+M^2) space, where N is the number of organisms, $h$ is the height of the phylogeny, and M is the sum of family sizes. We apply the model to the evolution of gene content in Preoteobacteria using the gene families in the COG (Clusters of Orthologous Groups) database

Retrieval of stratospheric aerosol density profiles from SCIAMACHY limb radiance measurements in the O₂ A-band

In this paper we present an approach to retrieve stratospheric aerosol number densities in the altitude range 10–40 km from SCIAMACHY limb radiance measurements in the spectral range of the O2 A absorption band, near 760 nm. Here, the characteristic light paths differ for the measured light in the O2 A-band and in the spectral continuum next to the absorption band. This difference is used to distinguish the effect of stratospheric aerosol scattering and ground reflection on the limb measurement. The capability to disentangle both effects is illustrated for SCIAMACHY limb observations over the Libyan desert, where the measurements are not affected by tropospheric clouds. Comparison of the SCIAMACHY retrieval and the SAGE II aerosol extinction product between 75&deg; southern and northern latitude shows the clear need for prior knowledge of the mean size of the stratospheric aerosol for the SCIAMACHY retrieval. We found best agreement between SCIAMACHY and SAGE II aerosol extinction for the period 2003–2005 for a prior choice of the mean aerosol size radius of 0.2 μm. The overall agreement between both data sets is in the range <50% root mean square difference at 14–30 km with a minimum of 30% at 22 km

Epigenetics and transcription regulation during eukaryotic diversification: the saga of TFIID

The basal transcription factor TFIID is central for RNA polymerase II-dependent transcription. Human TFIID is endowed with chromatin reader and DNA-binding domains and protein interaction surfaces. Fourteen TFIID TATA-binding protein (TBP)-associated factor (TAF) subunits assemble into the holocomplex, which shares subunits with the Spt–Ada–Gcn5–acetyltransferase (SAGA) coactivator. Here, we discuss the structural and functional evolution of TFIID and its divergence from SAGA. Our orthologous tree and domain analyses reveal dynamic gains and losses of epigenetic readers, plant-specific functions of TAF1 and TAF4, the HEAT2-like repeat in TAF2, and, importantly, the pre-LECA origin of TFIID and SAGA. TFIID evolution exemplifies the dynamic plasticity in transcription complexes in the eukaryotic lineage

Diabetes Lifestyle (e)Coaching 50 Weeks Follow Up; Technology Acceptance & e-Relationships

We report on the 50 weeks follow up results from a healthy lifestyle pilot (High Intensity Nutrition, Training & coaching), conducted with 11 insulin-dependent Type 2 Diabetes Mellites (DM2) patients. Hybrid eHealth support was given, with electronic support plus a multi-disciplinary health support team. Regarding the pilot goal of long term healthy lifestyle adoption in senior DM2 patients, challenges were: low ICT- and health literacy. This exploratory design analysis formulates design lessons based on 50 weeks follow up. The first 12 weeks contained intensive face-to-face and eSupported coaching. After that, patient self- management and eTools were key. After 50 weeks, attractiveness and feasibility of the intervention were perceived as high: recommendation 9,5 out of 10 and satisfaction 9,6 out of 10. TAM (Technology Acceptance Model) surveys showed high usefulness and feasibility. Acceptance and health behaviours were reinforced by the prolonged health results: Aerobic and strength capacity levels were improved at 50 weeks, plus Health Related Quality of Life (and biometric benefits and medication reductions, reported elsewhere). We draw three types of conclusions. First, patients’ health literacy and quality of life improved strongly, which both supported healthy behaviours, even after 50 weeks. Second, regarding eHealth theory, iterative growth cycles are beneficial for long term adoption and e-relationships. Third, a design analysis was conducted regarding long term service mix efficacy in relation to key requirements for designing ICT-enabled lifestyle interventions. Several suggestions for long term lifestyle eSupport are given

Intensive Lifestyle (e)Support to Reverse Diabetes-2

Advanced diabetes-type-2 patients often have high insulin resistance. Over the years their insulin medication rises, which further increases their insulin resistance and glucose management problems. A HINTc (High Intensity Nutrition, Training & coaching) pilot study was conducted with 11 insulin-dependent patients. Hybrid eHealth support was given, with electronic support plus a multi-disciplinary health support team. Based on preliminary 12 week results, attractiveness and feasibility of the intervention were high: recommendation 9,0 out of 10 and satisfaction 9,1 out of 10. TAM (Technology Acceptance Model) surveys showed high usefulness, feasibility and intentions for future use. Acceptance and health behaviours were also reinforced by the rapid results (average 9% weight loss, 20% lower fasting glucose and 71% lower insulin medication, plus a 46% increase on the Quality of Life Physical Health dimension). Our analysis supports three types of conclusions. First, patients’ health literacy and quality of life improved strongly, both supporting healthier behaviours. Second, a virtuous cycle was started, helping patients reverse diabetes-2 progression. Third, a design analysis was conducted regarding service mix efficacy in relation to key requirements for designing ICT-enabled lifestyle interventions

Bioinformatic Inference of Specific and General Transcription Factor Binding Sites in the Plant Pathogen Phytophthora infestans

Plant infection by oomycete pathogens is a complex process. It requires precise expression of a plethora of genes in the pathogen that contribute to a successful interaction with the host. Whereas much effort has been made to uncover the molecular systems underlying this infection process, mechanisms of transcriptional regulation of the genes involved remain largely unknown. We performed the first systematic de-novo DNA motif discovery analysis in Phytophthora. To this end, we utilized the genome sequence of the late blight pathogen Phytophthora infestans and two related Phytophthora species (P. ramorum and P. sojae), as well as genome-wide in planta gene expression data to systematically predict 19 conserved DNA motifs. This catalog describes common eukaryotic promoter elements whose functionality is supported by the presence of orthologs of known general transcription factors. Together with strong functional enrichment of the common promoter elements towards effector genes involved in pathogenicity, we obtained a new and expanded picture of the promoter structure in P. infestans. More intriguingly, we identified specific DNA motifs that are either highly abundant or whose presence is significantly correlated with gene expression levels during infection. Several of these motifs are observed upstream of genes encoding transporters, RXLR effectors, but also transcriptional regulators. Motifs that are observed upstream of known pathogenicity-related genes are potentially important binding sites for transcription factors. Our analyses add substantial knowledge to the as of yet virtually unexplored question regarding general and specific gene regulation in this important class of pathogens. We propose hypotheses on the effects of cis-regulatory motifs on the gene regulation of pathogenicity-related genes and pinpoint motifs that are prime targets for further experimental validation