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Search Results: 1 - 10 of 2872 matches for " Gabriele Martino "
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A Sieve for Prime Based on Extension Form of Not Prime  [PDF]
Gabriele Martino
American Journal of Computational Mathematics (AJCM) , 2013, DOI: 10.4236/ajcm.2013.31014
Abstract:

This paper will illustrate two versions of an algorithm for finding prime number up to N, which give the first version complexity

\"\" (1)

where c1, c2 are constants, and N is the input dimension, and gives a better result for the second version. The method is based on an equation that expresses the behavior of not prime numbers. With this equation it is possible to construct a fast iteration to verify if the not prime number is generated by a prime and with which parameters. The second method differs because it does not pass other times over a number that has been previously evaluated as not prime. This is possible for a recurrence of not prime number that is (mod 3) = 0. The complexity in this case is better than the first. The comparison is made most with Mathematics than by computer calculation as the number N should be very big to appreciate the difference between the two versions. Anyway the second version results better. The algorithms have been

Primality Test  [PDF]
Gabriele Martino
American Journal of Computational Mathematics (AJCM) , 2013, DOI: 10.4236/ajcm.2013.31009
Abstract:

In this paper we will give an algorithm that in the worst case solve the question about the primality of a number in \"\" but that gives better result if the number is not prime (constant operation). Firstly, we will introduce an equation on which are based not prime numbers. With this equation it is possible to deduce the prime number that generates a not prime number and to establish an equation in which if exists a certain integer the number is not prime and therefore vice versa to deduce if it is prime.

Solving a Traveling Salesman Problem with a Flower Structure  [PDF]
Gabriele Martino
Journal of Applied Mathematics and Physics (JAMP) , 2014, DOI: 10.4236/jamp.2014.27079
Abstract:

This works aims to give an answer to the problem P = NP? The result is positive with the criteria that solve the Traveling Salesman Problem in polynomial cost of the input size and a proof is given. This problem gets a solution because a polyhedron, with a cut flower looking, is introduced instead of graph (e.g. tree).

On involutions in extremal self-dual codes and the dual distance of semi self-dual codes
Martino Borello,Gabriele Nebe
Computer Science , 2014,
Abstract: A classical result of Conway and Pless is that a natural projection of the fixed code of an automorphism of odd prime order of a self-dual binary linear code is self-dual. In this paper we prove that the same holds for involutions under some (quite strong) conditions on the codes. In order to prove it, we introduce a new family of binary codes: the semi self-dual codes. A binary self-orthogonal code is called semi self-dual if it contains the all-ones vector and is of codimension 2 in its dual code. We prove upper bounds on the dual distance of semi self-dual codes. As an application we get the following: let C be an extremal self-dual binary linear code of length 24m and s in Aut(C) be a fixed point free automorphism of order 2. If m is odd or if m=2k with binom{5k-1}{k-1} odd then C is a free F_2-module. This result has quite strong consequences on the structure of the automorphism group of such codes.
The automorphism group of a self-dual [72,36,16] code does not contain S_3, A_4, or D_8
Martino Borello,Francesca Dalla Volta,Gabriele Nebe
Mathematics , 2013,
Abstract: A computer calculation with Magma shows that there is no extremal self-dual binary code C of length 72, whose automorphism group contains the symmetric group of degree 3, the alternating group of degree 4 or the dihedral group of order 8. Combining this with the known results in the literature one obtains that Aut(C) has order at most 5 or isomorphic to the elementary abelian group of order 8.
Severe bleeding from esophageal varices resistant to endoscopic treatment in a non cirrhotic patient with portal hypertension
Roberto Caronna, Mario Bezzi, Monica Schiratti, Maurizio Cardi, Giampaolo Prezioso, Michele Benedetti, Federica Papini, Simona Mangioni, Gabriele Martino, Piero Chirletti
World Journal of Emergency Surgery , 2008, DOI: 10.1186/1749-7922-3-24
Abstract: Recent advances in interventional radiology, especially the introduction of endovascular portosystemic shunts, have brought about rapid changes in therapy for the complications of portal hypertension [1]. Although the preferred treatment for a patient with variceal bleeding related to portal hypertension remains endoscopic sclerotherapy, when this option fails, as it does in about 15% of the cases, the only alternative is an emergency portosystemic shunt [2]. A surgical shunt procedure is indicated in patients with Child-Pugh A cirrhosis, the transjugular intrahepatic portosystemic shunt (TIPS) in those with Child-Pugh B-C cirrhosis scheduled for liver transplantation [3]. The treatment of variceal bleeding raises different problems in cirrhotic and non cirrhotic patients with portal vein thrombosis. Whereas from 0.6 to 2.6% of patients with cirrhosis have spontaneous portal thrombosis, those without cirrhosis generally do not (Table 1) [4]. The major causes of portal thrombosis in these patients are hereditary or acquired coagulation defects and local factors that include intraabdominal infections (in particular close to hepatic hilum) and surgical or traumatic portal vein damage.We describe a case of severe recurrent hemorrhage from esophageal varices in a patient without cirrhosis who had undergone open cholecystectomy 12 months earlier. The failure of endoscopic therapy raised complex problems in deciding how to manage portal hypertension.A 58-year-old non alcoholic patient was admitted to hospital for investigation of hematemesis and melena. Twelve months earlier he had undergone elective open cholecystectomy for chronic calculous cholecystitis complicated by a biliary fistula that had resolved spontaneously. An esophagogastroduodenoscopy disclosed bloody esophageal varices and the bleeding was successfully controlled by endoscopic sclerotherapy. During repeated endoscopic sessions the varices were progressively eradicated by ligation. Laboratory serum screenin
The Interventions of Pietro da Cortona in the Crypt of Santa Maria in Via Lata in Rome, Studied through a Morphometric Three-Dimensional Survey  [PDF]
Lorenzo Pio Massimo Martino
Open Journal of Civil Engineering (OJCE) , 2014, DOI: 10.4236/ojce.2014.42009
Abstract:

Twenty years after the last archaeological researches and surveys, a new investigation has been carried out on the basement in the church of Santa Maria in Via Lata in Rome. The study has employed three-dimensional surveys with laser scanning methodology and has focused both on archaeological and architectural issues. Indeed, the present layout of the basement derives from a XVII century remodelling of early Christian and medieval spaces planned by Pietro da Cortona. The architect gave a unique setting and composition to the underground spaces, different in shapes and building materials, thanks to the refinement of his baroque language. Though he worked in small spaces with static problems connected to the foundations and to the loads of the church rising above, and with poor lighting and extreme dampness, Pietro da Cortona put skilfully together “modern” elements with ancient or historical pre-existences. The study focuses on Berrettini’s design process through a three-dimensional analysis with CAD systems, starting from the new XVII century fa?ade and from the articulated distribution of routes that led to the intimate underground interiors. Metrical processing gave the possibility to improve the knowledge about room geometry and to confirm the interpretations put forward by major scholars such as Krautheimer and Cavazzi.

On the variety of linear recurrences and numerical semigroups
Ivan Martino,Luca Martino
Mathematics , 2012,
Abstract: In this work, we prove the existence of linear recurrences of order M with a non-trivial solution vanishing exactly on the set of gaps (or a subset) of a numerical semigroup S finitely generated by a1 < a2 <...< aN and M = aN. Keywords: numerical semigroups, linear recurrences, generating function.
On the Fractal Design in Human Brain and Nervous Tissue  [PDF]
Gabriele A. Losa
Applied Mathematics (AM) , 2014, DOI: 10.4236/am.2014.512165
Abstract:


Digital imaging techniques have enabled to gain insight into complex structure-functional processes involved in the neo-cortex maturation and in brain development, already recognized in anatomical and histological preparations. Despite such a refined technical progress most diagnostic records sound still elusive and unreliable because of use of conventional morphometric approaches based on a unique scale of measure, inadequate for investigating irregular cellular components and structures which shape nervous and brain tissues. Instead, these could be efficiently analyzed by adopting principles and methodologies derived from the Fractal Geometry. Through his masterpiece, The Fractal Geometry of Nature [1], Benoît Mandelbrot has provided a novel epistemological framework for interpreting the real life and the natural world as they are, preventing whatever approximation or subjective sight. Founded upon a body of well-defined laws and coherent principles, the Fractal Geometry is a powerful tool for recognizing and quantitatively describing a good many kinds of complex shapes, living forms, organized patterns, and morphologic features long range correlated with a broad network of functional interactions and metabolic processes that contribute to building up adaptive responses making life sustainable. Scale free dynamics characterized biological systems which develop through the iteration of single generators on different scales thus preserving proper self-similar traits. In the last decades several studies have contributed to showing how relevant may be the recognition of fractal properties for a better understanding of brain and nervous tissues either in healthy conditions or in altered and pathological states.


Immune evasion by Plasmodium falciparum parasites: converting a host protection mechanism for the parasite′s benefit  [PDF]
Bismarck Dinko, Gabriele Pradel
Advances in Infectious Diseases (AID) , 2016, DOI: 10.4236/aid.2016.62011
Abstract: Immune evasion is a strategy used by pathogenic microbes to evade the host immune system in order to ensure successful propagation. Immune evasion is particularly important for the blood stages of Plasmodium falciparum, the causative agent of the deadly disease malaria tropica. Because Plasmodium blood stage parasites require human erythrocytes for replication, their ability to evade attack by the human immune system is essential for parasite survival. In order to escape immunity-induced killing, the intraerythrocytic parasites have evolved a variety of evasion mechanisms, including expansion of plasmodial surface proteins, organ-specific sequestration of the infected red blood cells and acquisition of immune-regulatory proteins by the parasite. This review aims to highlight recent advances in the molecular understanding of the immune evasion strategies by P. falciparum, including antigenic variation, surface protein polymorphisms and invasion ligand diversification. The review will further discuss new findings on the regulatory mechanisms applied by P. falciparum to avoid lysis by the human complement as well as killing by immune factors of the mosquito vector.
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