50 research outputs found
Incipient Separation in Shock Wave Boundary Layer Interactions as Induced by Sharp Fin
The incipient separation induced by the shock wave turbulent boundary layer
interaction at the sharp fin is the subject of present study. Existing theories
for the prediction of incipient separation, such as those put forward by McCabe
(1966) and Dou and Deng (1992), can have thus far only predicting the direction
of surface streamline and tend to over-predict the incipient separation
condition based on the Stanbrook's criterion. In this paper, the incipient
separation is firstly predicted with Dou and Deng (1992)'s theory and then
compared with Lu and Settles (1990)' experimental data. The physical mechanism
of the incipient separation as induced by the shock wave/turbulent boundary
layer interactions at sharp fin is explained via the surface flow pattern
analysis. Furthermore, the reason for the observed discrepancy between the
predicted and experimental incipient separation conditions is clarified. It is
found that when the wall limiting streamlines behind the shock wave becomes\
aligning with one ray from the virtual origin as the strength of shock wave
increases, the incipient separation line is formed at which the wall limiting
streamline becomes perpendicular to the local pressure gradient. The formation
of this incipient separation line is the beginning of the separation process.
The effects of Reynolds number and the Mach number on incipient separation are
also discussed. Finally, a correlation for the correction of the incipient
separation angle as predicted by the theory is also given.Comment: 34 pages; 9 figure
Probing exotic phenomena at the interface of nuclear and particle physics with the electric dipole moments of diamagnetic atoms: A unique window to hadronic and semi-leptonic CP violation
The current status of electric dipole moments of diamagnetic atoms which
involves the synergy between atomic experiments and three different theoretical
areas -- particle, nuclear and atomic is reviewed. Various models of particle
physics that predict CP violation, which is necessary for the existence of such
electric dipole moments, are presented. These include the standard model of
particle physics and various extensions of it. Effective hadron level combined
charge conjugation (C) and parity (P) symmetry violating interactions are
derived taking into consideration different ways in which a nucleon interacts
with other nucleons as well as with electrons. Nuclear structure calculations
of the CP-odd nuclear Schiff moment are discussed using the shell model and
other theoretical approaches. Results of the calculations of atomic electric
dipole moments due to the interaction of the nuclear Schiff moment with the
electrons and the P and time-reversal (T) symmetry violating
tensor-pseudotensor electron-nucleus are elucidated using different
relativistic many-body theories. The principles of the measurement of the
electric dipole moments of diamagnetic atoms are outlined. Upper limits for the
nuclear Schiff moment and tensor-pseudotensor coupling constant are obtained
combining the results of atomic experiments and relativistic many-body
theories. The coefficients for the different sources of CP violation have been
estimated at the elementary particle level for all the diamagnetic atoms of
current experimental interest and their implications for physics beyond the
standard model is discussed. Possible improvements of the current results of
the measurements as well as quantum chromodynamics, nuclear and atomic
calculations are suggested.Comment: 46 pages, 19 tables and 16 figures. A review article accepted for
EPJ
Analysis of isometric cervical strength with a nonlinear musculoskeletal model with 48 degrees of freedom
Emulating a trial of joint dynamic strategies: An application to monitoring and treatment of HIV-positive individuals
Decisions about when to start or switch a therapy often depend on the frequency with which individuals are monitored or tested. For example, the optimal time to switch antiretroviral therapy depends on the frequency with which HIV-positive individuals have HIV RNA measured. This paper describes an approach to use observational data for the comparison of joint monitoring and treatment strategies and applies the method to a clinically relevant question in HIV research: when can monitoring frequency be decreased and when should individuals switch from a first-line treatment regimen to a new regimen?. We outline the target trial that would compare the dynamic strategies of interest and then describe how to emulate it using data from HIV-positive individuals included in the HIV-CAUSAL Collaboration and the Centers for AIDS Research Network of Integrated Clinical Systems. When, as in our example, few individuals follow the dynamic strategies of interest over long periods of follow-up, we describe how to leverage an additional assumption: no direct effect of monitoring on the outcome of interest. We compare our results with and without the “no direct effect†assumption. We found little differences on survival and AIDS-free survival between strategies where monitoring frequency was decreased at a CD4 threshold of 350 cells/μl compared with 500 cells/μl and where treatment was switched at an HIV-RNA threshold of 1000 copies/ml compared with 200 copies/ml. The “no direct effect†assumption resulted in efficiency improvements for the risk difference estimates ranging from an 7- to 53-fold increase in the effective sample size
No evidence that protein truncating variants in BRIP1 are associated with breast cancer risk: implications for gene panel testing.
BACKGROUND: BRCA1 interacting protein C-terminal helicase 1 (BRIP1) is one of the Fanconi Anaemia Complementation (FANC) group family of DNA repair proteins. Biallelic mutations in BRIP1 are responsible for FANC group J, and previous studies have also suggested that rare protein truncating variants in BRIP1 are associated with an increased risk of breast cancer. These studies have led to inclusion of BRIP1 on targeted sequencing panels for breast cancer risk prediction. METHODS: We evaluated a truncating variant, p.Arg798Ter (rs137852986), and 10 missense variants of BRIP1, in 48 144 cases and 43 607 controls of European origin, drawn from 41 studies participating in the Breast Cancer Association Consortium (BCAC). Additionally, we sequenced the coding regions of BRIP1 in 13 213 cases and 5242 controls from the UK, 1313 cases and 1123 controls from three population-based studies as part of the Breast Cancer Family Registry, and 1853 familial cases and 2001 controls from Australia. RESULTS: The rare truncating allele of rs137852986 was observed in 23 cases and 18 controls in Europeans in BCAC (OR 1.09, 95% CI 0.58 to 2.03, p=0.79). Truncating variants were found in the sequencing studies in 34 cases (0.21%) and 19 controls (0.23%) (combined OR 0.90, 95% CI 0.48 to 1.70, p=0.75). CONCLUSIONS: These results suggest that truncating variants in BRIP1, and in particular p.Arg798Ter, are not associated with a substantial increase in breast cancer risk. Such observations have important implications for the reporting of results from breast cancer screening panels.The COGS project is funded through a European Commission's Seventh Framework Programme grant
(agreement number 223175 - HEALTH-F2-2009-223175). BCAC is funded by Cancer Research UK
[C1287/A10118, C1287/A12014] and by the European Community´s Seventh Framework Programme under
grant agreement number 223175 (grant number HEALTH-F2-2009-223175) (COGS). Funding for the iCOGS
infrastructure came from: the European Community's Seventh Framework Programme under grant agreement
n° 223175 (HEALTH-F2-2009-223175) (COGS), Cancer Research UK (C1287/A10118, C1287/A 10710,
C12292/A11174, C1281/A12014, C5047/A8384, C5047/A15007, C5047/A10692, C8197/A16565), the
National Institutes of Health (CA128978) and Post-Cancer GWAS initiative (1U19 CA148537, 1U19
16
CA148065 and 1U19 CA148112 - the GAME-ON initiative), the Department of Defense (W81XWH-10-1-
0341), the Canadian Institutes of Health Research (CIHR) for the CIHR Team in Familial Risks of Breast
Cancer, Komen Foundation for the Cure, the Breast Cancer Research Foundation, and the Ovarian Cancer
Research Fund. This study made use of data generated by the Wellcome Trust Case Control consortium.
Funding for the project was provided by the Wellcome Trust under award 076113. The results published here
are in part based upon data generated by The Cancer Genome Atlas Project established by the National Cancer
Institute and National Human Genome Research Institute.This is the author accepted manuscript. The final version is available from BMJ Group at http://dx.doi.org/10.1136/jmedgenet-2015-103529
MiCODetect : vers le cahier des charges d’un Capteur Optique de Détection présymptomatique de Septoria tritici pour la lutte intégrée contre la septoriose du blé
Ce volume rassemble l'ensemble des travaux de recherche conduits dans le cadre des appels à projets soutenus par le plan Ecophyto, et présentés à l'occasion du colloque Ecophyto Recherche des 13 et 14 octobre 2015National audienceSeptoria tritici blotch (STB) caused by the fungus Zymoseptoria tritici is the most important disease in wheat, and the first contributor to fungicide use in France and Europe. Adjusting sprayings to the specific requirements of the crop can lead to significant reductions in fungicide use without compromising yield. It has been shown that presymptomatic quantification of the pathogen could be key to achieve this. We hypothesized that the production of fluorescent secondary metabolites by the infected wheat crop could be used as biomarkers of the transition to necrotrophy, to quantify the pathogen, via an adapted sensor. We set up a metabolomic and transcriptomic screening of the wheatseptoria interaction and identified different upregulated metabolic pathways. Specifically, three metabolites from the tryptophan pathway are produced during infection, and emit UV-UV fluorescence. In the field, these metabolites are predictive of ulterior symptom dynamics, and modify the UV-UV spectrum of wheat leaves. Additional experiments will be necessary to determine which emission wavelengths are the most predictive, and to assess how specific and robust this fluorescence is.La septoriose provoquée par le champignon phytopathogène Zymoseptoria tritici est la 1ère maladie contributrice aux traitements fongicides sur blé en France et en Europe. Le raisonnement de son traitement au plus proche des besoins réels peut apporter des économies significatives de produit sans perte de performance technique. Pour cela, la quantification du champignon pendant sa phase asymptomatique d’incubation a été identifiée comme un point clef. Nous faisons l’hypothèse que des métabolites secondaires fluorescents produits par la plante en réponse à l’infection, servant de biomarqueurs de la transition biotrophie-nécrotrophie pourraient être quantifiés par un capteur ad hoc. Nous avons mis en place un protocole d’analyse métabolomique et transcriptomique de l’interaction blé- septoriose, et identifié plusieurs voies métaboliques induites. En particulier, trois métabolites secondaires issus de la voie du tryptophane sont produits lors de l’infection, et émettent une fluorescence dans l'ultra-violet (UV-UV). Au champ, la production de ces métabolites s’avère effectivement prédictive du développement ultérieur des symptômes, et modifie le spectre UV-UV des feuilles de blé. Des expérimentations complémentaires sont à effectuer pour préciser les longueurs d’onde d’émission les plus prédictives et établir le degré de spécificité et de robustesse de ce signal fluorescent