499 research outputs found

    Shape-from-Template dans Flatland

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    International audienceLe Shape-from-template (SfT) consiste en la reconstruction d'un objet dĂ©formable observĂ© sur une image grĂące Ă  sa forme de rĂ©fĂ©rence. Le 2DSfT est le cas usuel du SfT oĂč la forme de rĂ©fĂ©rence est une surface plongĂ©e dans un espace 3D et l'image une projection 2D. Nous prĂ©sentons le 1DSfT, un nouveau cas du SfT oĂč la forme de rĂ©fĂ©rence est une courbe plongĂ©e dans un espace 2D et l'image une projection 1D. Nous nous concentrons sur les dĂ©formations isomĂ©triques, pour lesquelles le 2DSfT est un problĂšme bien posĂ©. À travers une Ă©tude thĂ©orique du 1DSfT avec projection perspective, nous montrons que ce cas est liĂ© au 2DSfT, mais qu'il possĂšde des propriĂ©tĂ©s diffĂ©rentes : (i) le 1DSfT ne possĂšde pas de solution Ă  la fois exacte et locale et (ii) le 1DSfT ne possĂšde pas de solution unique, mais un nombre fini d'au moins deux solutions. Ensuite, nous proposons deux mĂ©thodes d'initialisation convexes: une solution locale et analytique basĂ©e sur la linĂ©aritĂ© infinitĂ©simale et une solution globale basĂ©e sur l'inextensibilitĂ©. Nous montrons comment le raffinement non-convexe peut ĂȘtre implĂ©mentĂ© et comment l'isomĂ©trie peut ĂȘtre contrainte avec une nouvelle paramĂ©trisation basĂ©e sur l'angle. Enfin, notre mĂ©thode est testĂ©e sur des donnĂ©es simulĂ©es et rĂ©elles

    Multiperiodicity in the newly discovered mid-late Be star V2104 Cygni

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    We obtained the first long, homogenous time-series of V2104Cyg, consisting of 679 datapoints, with the uvbybeta photometers of Sierra Nevada and San Pedro Martir Observatories with the aim to detect and subsequently interpret the intrinsic frequencies of this previously unstudied variable star, which turned out to be a Be star. We try to figure out its place among the variable B stars on the upper Main Sequence. In order to obtain additional information on physical parameters we collected a few spectra with the ELODIE and FIES instruments. We searched for frequencies in the uvby passbands using 2 different frequency analysis methods and used the S/N>4 criterion to select the significant periodicities. We obtained an estimate of the physical parameters of the underlying B star of spectral type between B5 and B7, by correcting for the presence of a circumstellar disk, using a formalism based on the strenght of the Halpha line emission. We detected 3 independent frequencies with amplitudes below 0.01mag, f1 = 4.7126 c/d, f2 = 2.2342 c/d and f3 = 4.671 c/d, and discovered that V2104Cyg is a Be star. The fast rotation (vsini=290+/-10 km/s, and 27<i<45) hampered the investigation of the associated pulsational parameters l. Nevertheless, the most plausible explanation for the observed variability of this mid-late type Be star is a non-radial pulsation model. This paper is based on observations obtained at the Observatorio Astronomico Nacional San Pedro Martir (Mexico), Observatorio de Sierra Nevada (Spain), Observatoire de Haute Provence (France), and on observations made with the Nordic Optical Telescope, Observatorio Roque de los Muchachos, La Palma, Spain.Comment: 7 pages, 4 figures, A&A accepte

    A distinctive requirement for p53 in the genome protective Topoisomerase 2a-dependent G2 arrest in hTERT positive cancer cells

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    Topoisomerase 2a (Topo2a)-dependent G2 arrest engenders faithful segregation of sister chromatids, yet in certain tumor cell lines where this arrest is dysfunctional, a PKCΔ-dependent failsafe pathway can be triggered. Here we elaborate on recent advances in understanding the underlying mechanisms associated with this G2 arrest by determining that p53-p21 signaling is essential for efficient arrest in cell lines, in patient-derived cells, and in colorectal cancer organoids. Regulation of this p53 axis required the SMC5/6 complex, which is distinct from the p53 pathways observed in the DNA damage response. Topo2a inhibition specifically during S phase did not trigger G2 arrest despite affecting completion of DNA replication. Moreover, in cancer cells reliant upon the alternative lengthening of telomeres (ALT) mechanism, a distinct form of Topo2a-dependent, p53-independent G2 arrest was found to be mediated by BLM and Chk1. Importantly, the previously described PKCΔ-dependent mitotic failsafe was engaged in hTERT-positive cells when Topo2a-dependent G2 arrest was dysfunctional and where p53 was absent, but not in cells dependent on the ALT mechanism. In PKCΔ knockout mice, p53 deletion elicited tumors were less aggressive than in PKCΔ-replete animals and exhibited a distinct pattern of chromosomal rearrangements. This evidence suggests the potential of exploiting synthetic lethality in arrest-defective hTERT-positive tumors through PKCΔ-directed therapeutic intervention.SignificanceThe identification of a requirement for p53 in stringent Topo2a-dependent G2 arrest and engagement of PKCΔ failsafe pathways in arrest-defective hTERT-positive cells provides a therapeutic opportunity to induce selective synthetic lethality

    iPreventÂź: a tailored, web-based, decision support tool for breast cancer risk assessment and management

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    We aimed to develop a user-centered, web-based, decision support tool for breast cancer risk assessment and personalized risk management. Using a novel model choice algorithm, iPrevent&reg; selects one of two validated breast cancer risk estimation models (IBIS or BOADICEA), based on risk factor data entered by the user. Resulting risk estimates are presented in simple language and graphic formats for easy comprehension. iPrevent&reg; then presents risk-adapted, evidence-based, guideline-endorsed management options. Development was an iterative process with regular feedback from multidisciplinary experts and consumers. To verify iPrevent&reg;, risk factor data for 127 cases derived from the Australian Breast Cancer Family Study were entered into iPrevent&reg;, IBIS (v7.02), and BOADICEA (v3.0). Consistency of the model chosen by iPrevent&reg; (i.e., IBIS or BOADICEA) with the programmed iPrevent&reg; model choice algorithm was assessed. Estimated breast cancer risks from iPrevent&reg; were compared with those attained directly from the chosen risk assessment model (IBIS or BOADICEA). Risk management interventions displayed by iPrevent&reg; were assessed for appropriateness. Risk estimation model choice was 100% consistent with the programmed iPrevent&reg;logic. Discrepant 10-year and residual lifetime risk estimates of &gt;1% were found for 1 and 4 cases, respectively, none was clinically significant (maximal variation 1.4%). Risk management interventions suggested by iPrevent&reg; were 100% appropriate. iPrevent&reg; successfully integrates the IBIS and BOADICEA risk assessment models into a decision support tool that provides evidence-based, risk-adapted risk management advice. This may help to facilitate precision breast cancer prevention discussions between women and their healthcare providers

    Fragmentation in jets at NNLO

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    The immunogenicity of ReFacto AF (moroctocog alfa AF-CC) in previously untreated patients with haemophilia A in the United Kingdom

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    Introduction Factor VIII inhibitor development is currently the most serious complication of the treatment of haemophilia A. Differences in manufacturing and the molecular structure of brands of recombinant factor VIII have led to speculation that concentrates may differ in immunogenicity. This has led to a regulatory focus on the immunogenicity of factor VIII concentrates both before and after licensure. Aim To investigate the immunogenicity of ReFacto AF post licensure in a real‐world setting in previously untreated patients (PUPs) treated exclusively with this product until at least 50 exposure days (EDs). Methods The United Kingdom Haemophilia Centre Doctors’ Organisation (UKHCDO) National Haemophilia Database (NHD) identified a consecutive cohort of patients with severe haemophilia A (<0.01 IU/L) whose first treatment was with ReFacto AF, monitored time to inhibitor development and described associated risk factors. Results One hundred and three boys reached 50 EDs within the study period, of whom 35 developed an inhibitor (P(t ≀ 50) = 0.33, [95% CI: 0.25‐0.43]), of which 15 (P(t ≀ 50) = 0.16, [95% CI: 0.10‐0.25]) were high titre. Inhibitors arose after a median (interquartile range) 11 (7‐16) EDs. Inhibitors were significantly associated with high‐risk mutations and non‐significantly associated with non‐white ethnicity. Inhibitors were negatively associated with a family history of haemophilia A. High‐titre inhibitors were significantly associated with a family history of inhibitors. Conclusion Inhibitor incidence in a single country population of ReFacto AF PUPs was similar to that previously described. Low‐ and high‐titre inhibitors were detected after a similar number of EDs, contrasting with previous data, probably reflecting standardized inhibitor monitoring within the United Kingdom
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