404 research outputs found

    Redesigning the Schedule Time Slots for Qatar University to Cope with Local Specificities

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    This study is concerned with the redesign of the class meeting pattern at Qatar University. It examines the existing meeting pattern based on its operational efficiency, its alignment with the strategic plan of the University, and its perception by the students and the faculty members. The analysis reveals serious limitations and shows the need for a new pattern with a full non-teaching day and no one-hour lectures. A capacity analysis proves the feasibility of such a pattern. Taking into consideration the specifications of the Qatari society, it was judged that the non-teaching day be split in two-half days. The present research recognizes the distinction between scheduling and class meeting patterns and aims to address the under-researched theme of having the meeting pattern as a variable rather than just an input to scheduling

    Multi-Estimator Full Left Ventricle Quantification through Ensemble Learning

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    Cardiovascular disease accounts for 1 in every 4 deaths in United States. Accurate estimation of structural and functional cardiac parameters is crucial for both diagnosis and disease management. In this work, we develop an ensemble learning framework for more accurate and robust left ventricle (LV) quantification. The framework combines two 1st-level modules: direct estimation module and a segmentation module. The direct estimation module utilizes Convolutional Neural Network (CNN) to achieve end-to-end quantification. The CNN is trained by taking 2D cardiac images as input and cardiac parameters as output. The segmentation module utilizes a U-Net architecture for obtaining pixel-wise prediction of the epicardium and endocardium of LV from the background. The binary U-Net output is then analyzed by a separate CNN for estimating the cardiac parameters. We then employ linear regression between the 1st-level predictor and ground truth to learn a 2nd-level predictor that ensembles the results from 1st-level modules for the final estimation. Preliminary results by testing the proposed framework on the LVQuan18 dataset show superior performance of the ensemble learning model over the two base modules.Comment: Jiasha Liu, Xiang Li and Hui Ren contribute equally to this wor

    Les Mélanomes Malins Nasosinusiens

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    Le mélanome malin nasosinusien est une tumeur rare prenant naissance au niveau des mélanocytes de la muqueuse respiratoire. Les auteurs rapportent deux observations de mélanomes malins nasosinusiens suivis et traités au service d\'ORL et de CCF de l\'hôpital Habib Thameur entre 1999 et 2005. Il s\'agit d\'un homme et d\'une femme âgés respectivement de 62 et 68 ans. La symptomatologie clinique est dominée par l\'obstruction nasale et l\'épistaxis. Le diagnostic est histologique après biopsie de la tumeur. Le traitement chirurgical est suivi d\'une radiothérapie externe dans les deux cas. L\'évolution est marquée par une récidive tumorale dans un cas. Primary mucosal melanoma of the nasal cavity and paranasal sinuses is an uncommun clinical entity occurring on the level of the melanocytes respiratory mucous membrane. The authors report two observations of malignant melanoma of sinonasal mucosa treated between 1999 and 2005. It acts of an old man and a woman respectively 62 and 68 years old, both presented with nasal obstruction and epistaxis. The diagnosis was histological after biopsy of the tumour. The surgical treatment was followed of an external radiotherapy in both cases. The evolution was marked by a local recurrence in one case. Journal Tunisien d\'ORL et de chirurgie cervico-faciale Vol. 16 2006: pp. 50-5

    Le carcinome indifférencié des glandes salivaires

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    Le carcinome indifferencie primitif des glandes salivaires est rare. Son association avec le virus Epstein Barr, initialement decrite chez les esquimaux, est retrouvee dans la majorite des cas publies. Nous rapportons un nouveau cas tunisien survenu chez un homme age de 64 ans, revele par une tumefaction de la glande parotide gauche. Microscopiquement se discutait le caractere primitif ou secondaire de la tumeur, etaye par les examens complementaires. Le patient etait traite par une parotidectomie suivie d’un curage ganglionnaire et d’une radiotherapie. L’evolution etait favorable apres un an de recul.  Mots clès : Glande salivaire- Carcinome indifferencie- Virus Epstein Bar

    Blow-up solutions for linear perturbations of the Yamabe equation

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    For a smooth, compact Riemannian manifold (M,g) of dimension N \geg 3, we are interested in the critical equation Δgu+(N2/4(N1)Sg+ϵh)u=uN+2/N2inM,u>0inM,\Delta_g u+(N-2/4(N-1) S_g+\epsilon h)u=u^{N+2/N-2} in M, u>0 in M, where \Delta_g is the Laplace--Beltrami operator, S_g is the Scalar curvature of (M,g), hC0,α(M)h\in C^{0,\alpha}(M), and ϵ\epsilon is a small parameter

    Second best toll and capacity optimisation in network: solution algorithm and policy implications

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    This paper looks at the first and second-best jointly optimal toll and road capacity investment problems from both policy and technical oriented perspectives. On the technical side, the paper investigates the applicability of the constraint cutting algorithm for solving the second-best problem under elastic demand which is formulated as a bilevel programming problem. The approach is shown to perform well despite several problems encountered by our previous work in Shepherd and Sumalee (2004). The paper then applies the algorithm to a small sized network to investigate the policy implications of the first and second-best cases. This policy analysis demonstrates that the joint first best structure is to invest in the most direct routes while reducing capacities elsewhere. Whilst unrealistic this acts as a useful benchmark. The results also show that certain second best policies can achieve a high proportion of the first best benefits while in general generating a revenue surplus. We also show that unless costs of capacity are known to be low then second best tolls will be affected and so should be analysed in conjunction with investments in the network

    Frequency and genome load of Epstein-Barr virus in 509 breast cancers from different geographical areas

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    Since the few data exploring a possible association between Epstein–Barr virus (EBV) and breast cancer are conflicting, we investigated this association together with the influences of geographical areas. 509 breast cancers were sampled from areas with varying risks of nasopharynx carcinoma (NPC) such as North Africa (Algeria and Tunisia, high-risk area); southern France (Marseille, intermediate-risk area); and northern Europe (northern France, the Netherlands and Denmark; low-risk areas). Polymerase chain reaction (PCR) of a subregion of EBV BamHIC encoding the EBERs demonstrated that 31.8% of the tumours contained the viral genome. No significant differences were observed among the geographical areas. However, positive samples showed higher loads of the EBV genome in the NPC high- and intermediate-risk areas than in the low-risk areas. EBV type 1 was the dominant strain. In situ hybridization studies using a35S-labelled riboprobe for EBER1 and a laser capture microdissection, combined with quantitative PCR, showed that EBV localization was restricted to some tumour epithelial cell clusters. EBV could not be detected in the stroma. Considering the whole population covered, the presence of the EBV genome was not correlated with age, menopausal status, tumour, size, nodal status or histological grade. © 2001 Cancer Research Campaign http://www. bjcancer.co

    Molecular analysis of HBV genotypes and subgenotypes in the Central-East region of Tunisia

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    <p>Abstract</p> <p>Background</p> <p>In Tunisia, country of intermediate endemicity for Hepatitis B virus (HBV) infection, most molecular studies on the virus have been carried out in the North of the country and little is known about other regions. The aim of this study was to determine HBV genotype and subgenotypes in Central-East Tunisia. A total of 217 HBs antigen positive patients were enrolled and determination of genotype was investigated in 130 patients with detectable HBV DNA. HBV genotyping methods were: PCR-RFLP on the pre-S region, a PCR using type-specific primers in the S region (TSP-PCR) and partial sequencing in the pre-S region.</p> <p>Results</p> <p>Three genotypes (D, B and A) were detected by the PCR-RFLP method and two (D and A) with the TSP-PCR method, the concordance between the two methods was 93%. Sequencing and phylogenetic analysis of 32 strains, retrieved the same genotype (D and A) for samples with concordant results and genotype D for samples with discordant results. The sequences of discordant genotypes had a restriction site in the pre-S gene which led to erroneous result by the PCR-RFLP method. Thus, prevalence of genotype D and A was 96% and 4%, respectively. Phylogenetic analysis showed the predominance of two subgenotypes D1 (55%) and D7 (41%). Only one strain clustered with D3 subgenotype (3%).</p> <p>Conclusions</p> <p>Predominance of subgenotype D7 appears to occur in northern regions of Africa with transition to subgenotype D1 in the East of the continent. HBV genetic variability may lead to wrong results in rapid genotyping methods and sequence analysis is needed to clarify atypical results.</p
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