P Systems Goedelization

This paper presents a method for assigning natural numbers to Transition P systems based on a Gödelization process. The paper states step by step the way for obtaining Gödel numbers for each one of the fundamental elements of Transition P systems –multisets of objects, evolution rules, priorities relation, membrane structure- until defining the Gödel number of a given Transition P system.

Asymmetric Cipher Protocol Using Decomposition Problem

The asymmetric cipher protocol based on decomposition problem in matrix semiring M over semiring of natural numbers N is presented. The security parameters are defined and preliminary security analysis is presented.

Алгоритмы Решения Систем Линейных Диофантовых Уравнений в Дискретных Областях

Abstract.The algorithms for computation of minimal supported set of solutions for systems of linear Diophantine homogeneous equations over set of natural numbers and basis of systems of linear Diophantine homogeneous and inhomogeneous equations in ring and field of remainders on modulo of a number.

A Representation of Binary Matrices

Христина Костадинова, Красимир Йорджев - В статията се обсъжда представянето на произволна бинарна матрица с помощта на последователност от цели неотрицателни числа. Разгледани са някои предимства и недостатъци на това представяне като алтернатива на стандартното, общоприето представяне чрез двумерен масив. Показано е, че представянето на бинарните матрици с помощта на наредени n-торки от естествени числа води до по-бързи алгоритми и до съществена икономия на оперативна памет. Използуван е апарата на обектно-ориентираното програмиране със синтаксиса и семантиката на езика C++.

Metodología Multimedia y Evolución del Pensamiento Matemático Ordinal Prenumérico en escolares de 3 a 7 años

En esta investigación se aborda el problema de analizar y conocer una parte de la evolución del Pensamiento Ordinal prenumérico y recursivo en escolares de 3 a 7 años, como parte y fundamento de la evolución cognitiva del Pensamiento Numérico y Aritmético, y comprobar si la utilización de una metodología de investigación basada en la tecnología multimedia (Metodología Multimedia) proporciona información válida y relevante sobre dicha evolución. Para el desarrollo del estudio se ha empleado una metodología mixta con dos componentes principales: • La componente teórica, dirigida a fundamentar y validar el marco conceptual así como el procedimiento y los resultados obtenidos. Dicha fundamentación en los niveles matemático, epistemológico y fenomenológico se complementa con los antecedentes específicos de los dos campos básicos del estudio: pensamiento ordinal y tecnología multimedia. • La componente empírica, orientada a obtener información sobre los comportamientos de sujetos en torno a los aspectos fundamentales del problema de investigación, mediante la aplicación de los bloques de tareas multimedia, el análisis e interpretación de las respuestas, la identificación de las estrategias utilizadas y los errores cometidos, la determinación de perfiles y niveles de competencias ordinales y la determinación de las características básicas del desarrollo y la evolución con la edad de dichas capacidades y competencias. La culminación del estudio teórico ha consistido en la construcción de un modelo evolutivo de competencias ordinales y recursivas (MECOR) ), que proporciona un marco interpretativo de las características, regularidades y evolución del Pensamiento Ordinal Preinductivo en escolares de 3 a 7 años, y de un modelo general para el diseño del ítem multimedia (MGDIM) que permite establecer un procedimiento general que hemos definido y denominado "Metodología Multimedia" para la investigación en Educación Matemática, y en otras áreas educativas, idónea para su utilización en estudios de masas. Las construcciones anteriores han permitido, como consecuencia, la elaboración de un instrumento metodológico operativo para el estudio de las características del pensamiento ordinal y su evolución en sujetos de 3 a 7 años de edad. Desde el punto de vista empírico se aplica el instrumento multimedia construido incluyendo los mecanismos necesarios para el registro automático de todas las interacciones de los sujetos con todas y cada una de las tareas del estudio, minimizando la interacción investigador--sujeto, constatándose la libertad y espontaneidad de las respuestas de los sujetos, la gran variedad de datos obtenidos y la facilidad de análisis de los comportamientos que proporcionan los instrumentos utilizados. Además de las indicadas, la investigación realiza las siguientes aportaciones: • Una explicación detallada de la evolución de una parte de las capacidades ordinales y recursivas en escolares de 3 a 7 años. • Una caracterización de niveles de competencia y determinación de las edades más frecuentes en las que tienen lugar los cambios de nivel. • La detección y clasificación de los errores cometidos y las estrategias utilizadas. • La identificación de las edades a las que aparece: a) el uso de capacidades recursivas frente al mero etiquetaje, b) la distinción entre cantidad continua y discreta en la resolución de tareas ordinales, c) el conteo ordinal frente a otras estrategias en la resolución de tareas ordinales con cantidades discretas. • Una descripción general de las capacidades, competencias y estrategias asociadas a los estados del modelo (MECOR) por grupos de edad. • La determinación de modelos de ajuste no lineales para la evolución de las medias de las valoraciones por grupos de edad para cada una de las capacidades tratadas y la comprobación de que dichos modelos son más precisos que los ajustes lineales correspondientes. • Ejemplos prácticos de ítems multimedia para el desarrollo de investigaciones futuras. Sobre la relevancia de la investigación, podemos destacar entre otros los siguientes motivos: la necesidad de conocer en profundidad las características del pensamiento matemático de los alumnos de la etapa de Educación Infantil para mejorar el diseño y desarrollo didáctico del proceso formativo en dicha etapa, así como la necesidad de encontrar procedimientos y métodos orientados a disminuir los inconvenientes tradicionales que surgen en las investigaciones con sujetos de tan corta edad. Por otra parte creemos que el estudio es del máximo interés por la novedad de los instrumentos utilizados, la importancia del tema analizado y la proyección que los conocimientos pueden tener sobre nuevas formas de ver y tratar los contenidos matemáticos, nuevos métodos de investigación así como nuevas formas de abordar el diseño y desarrollo didáctico en las etapas de Educación Infantil y Primaria. Desde el punto de vista de la metodología, consideramos de vital importancia la validación de una metodología nueva que puede aportar información privilegiada sobre el aprendizaje y la cognición de sujetos cuyos comportamientos y respuestas se han caracterizado desde hace tiempo por su enorme dificultad de interpretación y, consecuentemente, por las dudas en cuanto a la validez y fiabilidad de los resultados. En este sentido creemos que estamos ante una de las metodologías que pueden aportar avances notables en el campo de la investigación en Educación Matemática.

Generando números de Pitágoras

Este trabajo busca mostrar una forma general de encontrar arreglos de tres números naturales (tercias) que cumplen la relación de Pitágoras, es decir que la suma del cuadrado de los dos menores de como resultado el cuadrado del mayor, a través de un proceso mucho más general que los conocidos hasta ahora, llegando incluso a proponer unas fórmulas que, en función de dos parámetros permite encontrar dichos conjuntos de tres elementos, cuyos resultados se los presenta en unas tablas. Los resultados afirman la idea de que existe un infinito número de tercias que cumplen la relación de Pitágoras. Luego veremos cómo se puede usar estas tablas para construir relaciones donde la suma de los cuadrados de más de dos números es igual al cuadrado de otro.

Lower numbers of circulating natural killer T (NK T) cells in individuals with human T lymphotropic virus type 1 (HTLV-1) associated neurological disease

Human T lymphotropic virus type 1 (HTLV-1) infects 10-20 million people worldwide. The majority of infected individuals are asymptomatic; however, approximately 3% develop the debilitating neurological disease HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). There is also currently no cure, vaccine or effective therapy for HTLV-1 infection, and the mechanisms for progression to HAM/TSP remain unclear. NK T cells are an immunoregulatory T cell subset whose frequencies and effector functions are associated critically with immunity against infectious diseases. We hypothesized that NK T cells are associated with HAM/TSP progression. We measured NK T cell frequencies and absolute numbers in individuals with HAM/TSP infection from two cohorts on two continents: Sao Paulo, Brazil and San Francisco, CA, USA, and found significantly lower levels when compared with healthy subjects and/or asymptomatic carriers. Also, the circulating NK T cell compartment in HAM/TSP subjects is comprised of significantly more CD4(+) and fewer CD8(+) cells than healthy controls. These findings suggest that lower numbers of circulating NK T cells and enrichment of the CD4(+) NK T subset are associated with HTLV-1 disease progression.

Lower numbers of natural killer T cells in HIV-1 and Mycobacterium leprae co-infected patients

Natural killer T (NKT) cells are a heterogeneous population of lymphocytes that recognize antigens presented by CD1d and have attracted attention because of their potential role linking innate and adaptive immune responses. Peripheral NKT cells display a memory-activated phenotype and can rapidly secrete large amounts of pro-inflammatory cytokines upon antigenic activation. In this study, we evaluated NKT cells in the context of patients co-infected with HIV-1 and Mycobacterium leprae. The volunteers were enrolled into four groups: 22 healthy controls, 23 HIV-1-infected patients, 20 patients with leprosy and 17 patients with leprosy and HIV-1-infection. Flow cytometry and ELISPOT assays were performed on peripheral blood mononuclear cells. We demonstrated that patients co-infected with HIV-1 and M.leprae have significantly lower NKT cell frequencies [median 0.022%, interquartile range (IQR): 0.0070.051] in the peripheral blood when compared with healthy subjects (median 0.077%, IQR: 0.0320.405, P < 0.01) or HIV-1 mono-infected patients (median 0.072%, IQR: 0.0300.160, P < 0.05). Also, more NKT cells from co-infected patients secreted interferon-? after stimulation with DimerX, when compared with leprosy mono-infected patients (P = 0.05). These results suggest that NKT cells are decreased in frequency in HIV-1 and M.leprae co-infected patients compared with HIV-1 mono-infected patients alone, but are at a more activated state. Innate immunity in human subjects is strongly influenced by their spectrum of chronic infections, and in HIV-1-infected subjects, a concurrent mycobacterial infection probably hyper-activates and lowers circulating NKT cell numbers.

Atlantic journal, and friend of knowledge. In eight numbers. Containing about 160 original articles and tracts on natural and historical sciences, the description of about 150 new plants, and 100 new animals or fossils. Many vocabularies of languages, historical and geological facts, &c.

Caption title: nos. 1-4, Atlantic journal, and firend of knowledge; a cyclopedic journal and review of universal science and knowledge: historical, natural, and medical arts and sciences. -- nos. 5-8, Atlantic journal and friend of knowledge; a quarterly journal of historical and natural sciences, useful knowledge, &c.

Mnemonics : or, The new science of artificial memory; explained in its application to the study of numbers, the sciences, and to useful occupations of life, whereby the natural memory is greatly assisted and strenghtened ...

Preface signed: T. W. D.

Trypanosoma cruzi: Effects of social stress in Calomys callosus a natural reservoir of infection

Social environment can represent a major source of stress affecting cortisol and/or corticosterone levels, thereby altering the immune response. We have investigated the effects of social isolation on the development of Trypanosoma cruzi infection in female Calomys callosus, a natural reservoir of this protozoan parasite. Animals were divided in groups of five animals each. The animals of one group were kept together in a single cage. In a second group, four females were kept together in a cage with one male. In the final group, five individuals were kept isolated in private cages. The isolated animals showed body weight reduction, decreased numbers of peritoneal macrophages, lower global leucocytes counts, smaller lytic antibody percentage and a significantly higher level of blood parasites compared to the other animals. Their behavior was also altered. They were more aggressive than grouped females, or females exposed to the presence of a male. These results suggest that isolation creates a distinct social behavior in which immunity is impaired and pathogenesis is enhanced. (C) 2008 Elsevier Inc. All rights reserved.

Increased number and function of natural killer cells in human immunodeficiency virus 1-positive subjects co-infected with herpes simplex virus 2

P>Natural killer (NK) cells bridge the interface between innate and adaptive immunity and are implicated in the control of herpes simplex virus 2 (HSV-2) infection. In subjects infected with human immunodeficiency virus 1 (HIV-1), the critical impact of the innate immune response on disease progression has recently come into focus. Higher numbers of NK cells are associated with lower HIV-1 plasma viraemia. Individuals with the compound genotype of killer cell immunoglobulin-like receptor (KIR) 3DS1 and human leucocyte antigen (HLA)-Bw4-80I, or who have alleles of KIR3DL1 that encode proteins highly expressed on the NK cell surface, have a significant delay in disease progression. We studied the effect of HSV-2 co-infection in HIV-1-infected subjects, and show that HSV-2 co-infection results in a pan-lymphocytosis, with elevated absolute numbers of CD4+ and CD8+ T cells, and NK cells. The NK cells in HSV-2 co-infected subjects functioned more efficiently, with an increase in degranulation after in vitro stimulation. The number of NK cells expressing the activating receptors NKp30 and NKp46, and expressing KIR3DL1 or KIR3DS1, was inversely correlated with HIV-1 plasma viral load in subjects mono-infected with HIV-1, but not in subjects co-infected with HSV-2. This suggests that HSV-2 infection mediates changes within the NK cell population that may affect immunity in HIV-1 infection.

Lower cytokine secretion ex vivo by natural killer T cells in HIV-infected individuals is associated with higher CD161 expression

Objective: Natural killer T (NKT) cells are efficiently targeted by HIV and severely reduced in numbers in the circulation of infected individuals. The functional capacity of the remaining NKT cells in HIV-infected individuals is poorly characterized. This study measured NKT cell cytokine production directly ex vivo and compared these responses with both the disease status and NKT subset distribution of individual patients. Methods: NKT cell frequencies, subsets, and ex-vivo effector functions were measured in the peripheral blood mononuclear cells of HIV-infected patients and healthy controls by flow cytometry. We measured cytokines from NKT cells after stimulation with either a-galactosyl ceramide-loaded CD1d dimers (DimerX-alpha GalCer) or phorbol myristate acetate and ionomycin. Results: The frequencies of NKT cells secreting interferon-gamma and tumor necrosis factor-alpha were significantly lower in HIV-infected patients than healthy controls after DimerX-alpha GalCer treatment, but responses were similar after treatment with phorbol myristate acetate and ionomycin. The magnitude of the interferon-gamma response to DimerX-alpha GalCer correlated inversely with the number of years of infection. Both interferon-gamma and tumor necrosis factor-alpha production in response to DimerX-alpha GalCer correlated inversely with CD161 expression. Conclusion: The ex-vivo Th1 responses of circulating NKT cells to CD1d-glycolipid complexes are impaired in HIV-infected patients. NKT cell functions may be progressively lost over time in HIV infection, and CD161 is implicated in the regulation of NKT cell responsiveness. (C) 2009 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins

The first strand transfer reaction of HIV-1 reverse transcription is more efficient in infected cells than in cell-free natural endogenous reverse transcription reactions

Background: In the presence of dNTPs, intact HIV-1 virions are capable of reverse transcribing at least part of their genome, a process known as natural endogenous reverse transcription (NERT). PCR analysis of virion DNA produced by NERT revealed that the first strand transfer reaction (1stST) was inefficient in intact virions, with minus strand (-) strong stop DNA (ssDNA) copy numbers up to 200 times higher than post-1stST products measured using primers in U3 and U5. This was in marked contrast to the efficiency of 1stST observed in single-round cell infection assays, in which (-) ssDNA and U3-U5 copy numbers were indistinguishable. Objectives: To investigate the reasons for the discrepancy in first strand transfer efficiency between intact cell-free virus and the infection process. Study design: Alterations of both NERT reactions and the conditions of cell infection were used to test whether uncoating and/or entry play a role in the discrepancy in first strand transfer efficiency. Results and Conclusions: The difference in 1stST efficiency could not be attributed simply to viral uncoating, since addition of very low concentrations of detergent to NERT reactions removed the viral envelope without disrupting the reverse transcription complex, and these conditions resulted in no improvement in 1stST efficiency. Virus pseudotyped with surface glycoproteins from either vesicular stomatitis virus or amphotrophic murine leukaemia virus also showed low levels of 1stST in low detergent NERT assays and equivalent levels of (-) ssDNA and 1stST in single-round infections of cells, demonstrating that the gp120-mediated infection process did not select for virions capable of carrying out 1stST. These data indicate that a post-entry event or factor may be involved in efficient HIV-1 reverse transcription in vivo. (C) 2002 Elsevier Science B.V. All rights reserved.

Populations of larvae of Anopheles spp. in natural breeding sites in Western Venezuela, an area of refractory malaria

Studies have been un dertaken into on the diversity and relative abundance of larvae of Anopheles (Nyssorhynchus) spp. in 22 permanent or temporary pools in an area of 70 km² in the eastern piedmont of the Venezuela Andes, between the mountains and the plains, an area in which malaria is refractory and A. nuñeztovari is present. Twelve species were identified, the most frequent, abundant and sympatric being A. triannulatus, A. albitarsis, A. nuñeztovari, A. oswaldoi and A. strodei. The samples from the permanent pools showed greater diversity of species and greater numbers of larvae than the samples from the temporary pools. The existence of the same larval associations in pools of other localities in the eastern piedmont of the Venezuelan Andes suggests the possibility of the making an ecological map of the breeding sites of A. nuñeztovari and for these anophelines in a region extending for 430 km.