231 research outputs found

    Flight and wind-tunnel comparisons of the inlet-airframe interaction of the F-15 airplane

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    The design of inlets and nozzles and their interactions with the airplane which may account for a large percentage of the total drag of modern high performance aircraft is discussed. The inlet/airframe interactions program and the flight tests conducted is described. Inlet drag and lift data from a 7.5% wind-tunnel model are compared with data from an F-15 airplane with instrumentation to match the model. Pressure coefficient variations with variable cowl angles, capture ratios, examples of flow interactions and angles of attack are for Mach numbers of 0.6, 0.9, 1.2, and 1.5 are presented

    Towards a strategy for the recovering of the Mediterranean monk seal in the Adriatic-Ionian Basin

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    Occasional but recurrent sightings indicate that the endangered Mediterranean monk seal is still present in most of its historical range within the Adriatic-Ionian region in the central Mediterranean Sea. However, in most of the adjacent countries, the species' abundance and distribution are practically unknown. An actively reproducing sub-population with a minimum of 25 adult/sub-adult seals lives in the Greek central Ionian Sea. The latter can form a nucleus from which the entire Adriatic-Ionian Basin could be re-colonized if adequate conservation measures are implemented throughout the area and in a coordinated manner. We examine the historical presence in the region as a baseline for providing a benchmark for conservation. We further look into the species' habitat availability, possibilities for a rapid population assessment and various parameters that are considered crucial for its conservation, such as the existence of Marine Protected Areas (MPAs), corridors for connectivity purposes as well as needs for raising public awareness. We recommend a series of interlinked actions within the framework of a conservation strategy the implementation of which will ensure the conditions for maintaining ecologically, demographically, and genetically viable sub-populations of this species emblematic for the entire Mediterranean Sea. To achieve this goal, a coalition of partners from this area is required in order to adopt the strategy and jointly implement the measures required

    Airports at Risk: The Impact of Information Sources on Security Decisions

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    Security decisions in high risk organizations such as airports involve obtaining ongoing and frequent information about potential threats. Utilizing questionnaire survey data from a sample of airport employees in European Airports across the continent, we analyzed how both formal and informal sources of security information affect employee's decisions to comply with the security rules and directives. This led us to trace information network flows to assess its impact on the degree employees making security decisions comply or deviate with the prescribed security rules. The results of the multivariate analysis showed that security information obtained through formal and informal networks differentially determine if employee will comply or not with the rules. Information sources emanating from the informal network tends to encourage employees to be more flexible in their security decisions while formal sources lead to be more rigid with complying with rules and protocols. These results suggest that alongside the formal administrative structure of airports, there exists a diverse and pervasiveness set of informal communications networks that are a potent factor in determining airport security levels

    Delineation of Cohen Syndrome Following a Large-Scale Genotype-Phenotype Screen

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    Cohen syndrome is an autosomal recessive condition associated with developmental delay, facial dysmorphism, pigmentary retinopathy, and neutropenia. The pleiotropic phenotype, combined with insufficient clinical data, often leads to an erroneous diagnosis and has led to confusion in the literature. Here, we report the results of a comprehensive genotype-phenotype study on the largest cohort of patients with Cohen syndrome assembled to date. We found 22 different COH1 mutations, of which 19 are novel, in probands identified by our diagnostic criteria. In addition, we identified another three novel mutations in patients with incomplete clinical data. By contrast, no COH1 mutations were found in patients with a provisional diagnosis of Cohen syndrome who did not fulfill the diagnostic criteria (“Cohen-like” syndrome). This study provides a molecular confirmation of the clinical phenotype associated with Cohen syndrome and provides a basis for laboratory screening that will be valuable in its diagnosis

    Prompt, early, and afterglow optical observations of five gamma-ray bursts (GRBs 100901A, 100902A, 100905A, 100906A, and 101020A)

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    We present results of the prompt, early, and afterglow optical observations of five gamma-ray bursts, GRBs 100901A, 100902A, 100905A, 100906A, and 101020A, made with the Mobile Astronomical System of TElescope-Robots in Russia (MASTER-II net), the 1.5-m telescope of Sierra-Nevada Observatory, and the 2.56-m Nordic Optical Telescope. For two sources, GRB 100901A and GRB 100906A, we detected optical counterparts and obtained light curves starting before cessation of gamma-ray emission, at 113 s and 48 s after the trigger, respectively. Observations of GRB 100906A were conducted with two polarizing filters. Observations of the other three bursts gave the upper limits on the optical flux; their properties are briefly discussed. More detailed analysis of GRB 100901A and GRB 100906A supplemented by Swift data provides the following results and indicates different origins of the prompt optical radiation in the two bursts. The light curves patterns and spectral distributions suggest a common production site of the prompt optical and high-energy emission in GRB 100901A. Results of spectral fits for GRB 100901A in the range from the optical to X-rays favor power-law energy distributions with similar values of the optical extinction in the host galaxy. GRB 100906A produced a smoothly peaking optical light curve suggesting that the prompt optical radiation in this GRB originated in a front shock. This is supported by a spectral analysis. We have found that the Amati and Ghirlanda relations are satisfied for GRB 100906A. An upper limit on the value of the optical extinction on the host of GRB 100906A is obtained.Comment: 18 pages, 14 figures, 14 tables, 5 machine readable tables; accepted for publication in MNRA

    Wide-Scale Analysis of Human Functional Transcription Factor Binding Reveals a Strong Bias towards the Transcription Start Site

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    We introduce a novel method to screen the promoters of a set of genes with shared biological function, against a precompiled library of motifs, and find those motifs which are statistically over-represented in the gene set. The gene sets were obtained from the functional Gene Ontology (GO) classification; for each set and motif we optimized the sequence similarity score threshold, independently for every location window (measured with respect to the TSS), taking into account the location dependent nucleotide heterogeneity along the promoters of the target genes. We performed a high throughput analysis, searching the promoters (from 200bp downstream to 1000bp upstream the TSS), of more than 8000 human and 23,000 mouse genes, for 134 functional Gene Ontology classes and for 412 known DNA motifs. When combined with binding site and location conservation between human and mouse, the method identifies with high probability functional binding sites that regulate groups of biologically related genes. We found many location-sensitive functional binding events and showed that they clustered close to the TSS. Our method and findings were put to several experimental tests. By allowing a "flexible" threshold and combining our functional class and location specific search method with conservation between human and mouse, we are able to identify reliably functional TF binding sites. This is an essential step towards constructing regulatory networks and elucidating the design principles that govern transcriptional regulation of expression. The promoter region proximal to the TSS appears to be of central importance for regulation of transcription in human and mouse, just as it is in bacteria and yeast.Comment: 31 pages, including Supplementary Information and figure

    Morbidity and Mortality After Benign Prostatic Hyperplasia Surgery: Data from the American College of Surgeons National Surgical Quality Improvement Program

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    Background and Purpose: With the aging population, it is becoming increasingly important to identify patients at risk for postsurgical complications who might be more suited for conservative treatment. We sought to identify predictors of morbidity after surgical treatment of benign prostatic hyperplasia (BPH) using a large national contemporary population-based cohort. Methods: Relying on the American College of Surgeons National Surgical-Quality Improvement Program (ACS-NSQIP; 2006?2011) database, we evaluated outcomes after transurethral resection of the prostate (TURP), laser vaporization of the prostate (LVP), and laser enucleation of the prostate (LEP). Outcomes included blood-transfusion rates, length of stay, complications, reintervention rates, and perioperative mortality. Multivariable logistic-regression analysis evaluated the predictors of perioperative morbidity and mortality. Results: Overall, 4794 (65.2%), 2439 (33.1%), and 126 (1.7%) patients underwent TURP, LVP, and LEP, respectively. No significant difference in overall complications (P=0.3) or perioperative mortality (P=0.5) between the three surgical groups was found. LVP was found to be associated with decreased blood transfusions (odds ratio [OR]=0.21; P=0.001), length of stay (OR=0.12; P30%) levels were the only predictors of lower overall complications and perioperative mortality. Conclusions: All three surgical modalities for BPH management were found to be safe. Advanced age and non-Caucasian race were independent predictors of adverse outcomes after BPH surgery. In patients with these attributes, conservative treatment might be a reasonable alternative. Also, preoperative hematocrit and albumin levels represent reliable predictors of adverse outcomes, suggesting that these markers should be evaluated before BPH surgery.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140378/1/end.2013.0805.pd

    The European Rare Kidney Disease Registry (ERKReg): objectives, design and initial results

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    BACKGROUND: The European Rare Kidney Disease Reference Network (ERKNet) recently established ERKReg, a Web-based registry for all patients with rare kidney diseases. The main objectives of this core registry are to generate epidemiological information, identify current patient cohort for clinical research, explore diagnostic and therapeutic management practices, and monitor treatment performance and patient's outcomes. The registry has a modular design that allows to integrate comprehensive disease-specific registries as extensions to the core database. The diagnosis (Orphacode) and diagnostic information (clinical, imaging, histopathological, biochemical, immunological and genetic) are recorded. Anthropometric, kidney function, and disease-specific management and outcome items informing a set of 61 key performance indicators (KPIs) are obtained annually. Data quality is ensured by automated plausibility checks upon data entry and regular offline database checks prompting queries. Centre KPI statistics and benchmarking are calculated automatically. RESULTS: Within the first 24 months since its launch, 7607 patients were enrolled to the registry at 45 pediatric and 12 specialized adult nephrology units from 21 countries. A kidney disease diagnosis had been established in 97.1% of these patients at time of enrolment. While 199 individual disease entities were reported by Orphacode, 50% of the cohort could be classified with 11, 80% with 43 and 95% with 92 codes. Two kidney diagnoses were assigned in 6.5% of patients; 5.9% suffered from syndromic disease. Whereas glomerulopathies (54.8%) and ciliopathies including autosomal dominant polycystic kidney disease (ADPKD) (31.5%) were the predominant disease groups among adults, the pediatric disease spectrum encompassed congenital anomalies of the kidney and urinary tract (CAKUT) (33.7%), glomerulopathies (30.7%), ciliopathies (14.0%), tubulopathies (9.2%), thrombotic microangiopathies (5.6%), and metabolic nephropathies (4.1%). Genetically confirmed diagnoses were reported in 24% of all pediatric and 12% adult patients, whereas glomerulopathies had been confirmed by kidney biopsy in 80.4% adult versus 38.5% pediatric glomerulopathy cases. CONCLUSIONS: ERKReg is a rapidly growing source of epidemiological information and patient cohorts for clinical research, and an innovative tool to monitor management quality and patient outcomes
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