Mohamed Ayad

Learn More
BACKGROUND The lifestyle risk factors for nasopharyngeal carcinoma (NPC) in North Africa are not known. METHODS From 2002 to 2005, we interviewed 636 patients and 615 controls from Algeria, Morocco and Tunisia, frequency-matched by centre, age, sex, and childhood household type (urban/rural). Conditional logistic regression was used to evaluate the(More)
Fix a positive integer and a finite set whose elements are in arithmetic progression. We give a formula for the number of nonempty subsets of this set that are coprime to the given integer. A similar formula is given when we restrict our attention to the subsets having the same fixed cardinality. These formulas generalize previous results of El Bachraoui.
Let A be a finite union of disjoint sets of consecutive integers and let n be a positive integer. We give a formula for the number of relatively prime subsets (resp., 1 relatively prime subsets of cardinality k) of A, which generalizes results of Nathanson, El Bachraoui and others. We give as well similar formulas for the number of subsets with gcd coprime(More)
This work was designated to monitor the coagulation abnormalities associated with the gradual progression of liver diseases. The study included fifty patients; forty were diagnosed with liver cirrhosis with different stages categorized according to the Childs-Pugh classification and another ten patients were diagnosed with hepatocellular carcinoma (HCC).(More)
2 The information contained in this document represents the current view of Microsoft Corporation on the issues discussed as of the date of publication. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information(More)
  • 1