On reducing the complexity of matrix clocks

Matrix clocks are a generalization of the notion of vector clocks that allows the local representation of causal precedence to reach into an asynchronous distributed computation's past with depth $x$, where $x\ge 1$ is an integer. Maintaining matrix clocks correctly in a system of $n$ nodes requires that everymessage be accompanied by $O(n^x)$ numbers, which reflects an exponential dependency of the complexity of matrix clocks upon the desired depth $x$. We introduce a novel type of matrix clock, one that requires only $nx$ numbers to be attached to each message while maintaining what for many applications may be the most significant portion of the information that the original matrix clock carries. In order to illustrate the new clock's applicability, we demonstrate its use in the monitoring of certain resource-sharing computations

Partially ordered distributed computations on asynchronous point-to-point networks

Asynchronous executions of a distributed algorithm differ from each other due to the nondeterminism in the order in which the messages exchanged are handled. In many situations of interest, the asynchronous executions induced by restricting nondeterminism are more efficient, in an application-specific sense, than the others. In this work, we define partially ordered executions of a distributed algorithm as the executions satisfying some restricted orders of their actions in two different frameworks, those of the so-called event- and pulse-driven computations. The aim of these restrictions is to characterize asynchronous executions that are likely to be more efficient for some important classes of applications. Also, an asynchronous algorithm that ensures the occurrence of partially ordered executions is given for each case. Two of the applications that we believe may benefit from the restricted nondeterminism are backtrack search, in the event-driven case, and iterative algorithms for systems of linear equations, in the pulse-driven case

A Genetic Screen for Dominant Enhancers of the Cell-Cycle Regulator α-Endosulfine Identifies Matrimony as a Strong Functional Interactor in Drosophila

The coordination of cell-cycle events with developmental processes is essential for the reproductive success of organisms. In Drosophila melanogaster, meiosis is tightly coupled to oocyte development, and early embryos undergo specialized S-M mitoses that are supported by maternal products. We previously showed that the small phosphoprotein α-endosulfine (Endos) is required for normal oocyte meiotic maturation and early embryonic mitoses in Drosophila. In this study, we performed a genetic screen for dominant enhancers of endos00003 and identified several genomic regions that, when deleted, lead to impaired fertility of endos00003/+ heterozygous females. We uncovered matrimony (mtrm), which encodes a Polo kinase inhibitor, as a strong dominant enhancer of endos. mtrm126 +/+ endos00003 females are sterile because of defects in early embryonic mitoses, and this phenotype is reverted by removal of one copy of polo. These results provide compelling genetic evidence that excessive Polo activity underlies the strong functional interaction between endos00003 and mtrm126. Moreover, we show that endos is required for the increased expression of Mtrm in mature oocytes, which is presumably loaded into early embryos. These data are consistent with the model that maternal endos antagonizes Polo function in the early embryo to ensure normal mitoses through its effects on Mtrm expression during late oogenesis. Finally, we also identified genomic deletions that lead to loss of viability of endos00003/+ heterozygotes, consistent with recently published studies showing that endos is required zygotically to regulate the cell cycle during development

Thymus irrigation and morphology in hybrid Dalland and Penarlan pigs

O objetivo desta pesquisa foi contribuir com dados relativos à morfologia e à irrigação do timo de fetos de suínos, resultantes do cruzamento entre as raças Dalland e Penarlan. Para tanto, foram utilizados 40 fetos de suínos (16 machos e 24 fêmeas), após óbito natural; eles foram doados pela Granja Beira-Rio, do município de Andradas (MG). O sistema vascular arterial dos animais foi preenchido com solução aquosa corada de látex (diluição a 50%), via aorta torácica, em seguida, houve fixação em formoldeído estabilizado (diluição a 10%), para posterior dissecação das artérias endereçadas aos lobos tímicos. As observações permitiram relatar que o timo foi irrigado por ramos diretos e indiretos das artérias cervicais superficiais direita e esquerda, carótidas comuns direita e esquerda, torácicas externas direita e esquerda e torácicas internas direita e esquerda. As principais artérias supridoras dos lobos tímicos cervicais foram as artérias cervicais superficiais, enquanto que o lobo torácico recebeu um maior número de ramos das artérias torácicas internas direita e esquerda. Após as análises estatísticas, foi possível concluir que não existe correlação entre o tamanho do timo e os ramos das artérias que o irrigam.This research aimed to contribute with data related to the morphology and irrigation of the thymus of swine fetuses, resulting from the mating between Dalland and Penarlan breeds. For this, 40 swine fetuses (16 males and 24 females) were used, after natural death; they were donated by Granja Beira-Rio, from the town of Andradas (MG). The arterial vascular system of animals was filled in with an aqueous solution of colored latex (50% dilution), via thoracic aorta, then, there was fixation in stabilized formaldehyde (10% dilution), for later dissection of arteries directed towards the thymic lobes. The observations allowed us to report that thymus was irrigated by the direct and indirect branches of the right and left superficial cervical arteries, right and left common carotid arteries, right and left external thoracic arteries, and right and left internal thoracic arteries. The main arteries supplying the thymic cervical lobes were the superficial cervical arteries, while the thoracic lobe received a major number of branches from the right and left internal thoracic arteries. After the statistical analyses, it was possible to conclude that there is no correlation between the thymus size and the branches of arteries irrigating it

Non-invasive respiratory monitoring using long-period fiber grating sensors

In non-invasive ventilation, continuous monitoring of respiratory volumes is essential. Here, we present a method for the measurement of respiratory volumes by a single fiber-grating sensor of bending and provide the proof-of-principle by applying a calibration-test measurement procedure on a set of 18 healthy volunteers. Results establish a linear correlation between a change in lung volume and the corresponding change in a local thorax curvature. They also show good sensor accuracy in measurements of tidal and minute respiratory volumes for different types of breathing. The proposed technique does not rely on the air flow through an oronasal mask or the observation of chest movement by a clinician, which distinguishes it from the current clinical practice

Strategic knowledge management: In search of a knowledge-based organizational model

This paper discusses the results and propositions of organizational knowledge management research conducted in the period 2001-2007. This longitudinal study had the unique goal of investigating and analyzing “Knowledge Management” (KM) processes effectively implemented in world class organizations. The main objective was to investigate and analyze the conceptions, motivations, practices, metrics and results of KM processes implemented in different industries. The first set of studies involved 20 world cases related in the literature and served as a basis for a theoretical framework entitled “KM Integrative Conceptual Mapping Proposition”. This theoretical proposal was then tested in a qualitative study in three large organizations in Brazil. The results of the qualitative study validated the mapping proposition and left questions for new research concerning the implementation of a knowledge-based organizational model strategy.Este artigo aborda os resultados e proposições da investigação da gestão do conhecimento organizacional conduzida no período de 2001-2007. Este estudo longitudinal teve como único objectivo o de investigar e analisar os processos de “Gestão do Conhecimento” (GC) eficazmente implementados no universo das organizações trabalham ou têm influência fora das fronteiras nacionais. O principal objectivo foi o de investigar e analisar concepções, motivações, práticas, métricas e resultados dos processos de GC existentes em diferentes indústrias. O primeiro conjunto de estudos envolveu 20 casos descritos na literatura e serviu de base para a abordagem teórica designada “Proposição do Mapa Conceptual Integrativo da GC”. Esta proposta teórica foi posteriormente testada através de um estudo qualitativo em três organizações de grande dimensão do Brasil. Os resultados do estudo qualitativo validaram a proposição do mapa e levantaram questões para nova investigação no âmbito da implementação de um modelo de estratégia organizacional baseado no conhecimento

Fatores que influenciam a escolha da área de atuação entre formandos em Terapia Ocupacional

The objectives of this study were to identify factors that influence the choice of professional acting area among Universidade Federal de Minas Gerais (UFMG) and Faculdade de Ciências Médicas de Minas Gerais (FCMMG) Occupational Therapy undergraduate students; to characterize the relevance of these factors in the choice of professional interest area and to compare specific choosing factors among the undergraduate students from both distinct (public and private schools) Occupational Therapy courses in the city of Belo Horizonte/MG. Surveying forms were distributed to all UFMG students graduating in the second semester of 2001, first and second semesters of 2002, and to the FCMMG graduating classes of 2001 and 2002. The data were analyzed with quantitative procedures by means of their statistical frequency. The results revealed the following factors as relevant, which were ranked higher (above 7 in 10) in their process of decision: fondness, vocation, readiness, relationship with professionals, curricular practical experience, faculty educational background, professor/student relationship, and area theoretical/clinical consistency. The results from this study may contribute to understanding the influences that these courses have on the graduating students and consequently, help to create problem solving.Os objetivos deste estudo foram identificar os fatores que influenciam a escolha da área de atuação profissional de graduandos de Terapia Ocupacional da Universidade Federal de Minas Gerais (UFMG) e da Faculdade de Ciências Médicas de Minas Gerais (FCMMG); caracterizar a relevância desses fatores na escolha da área de atuação profissional e comparar fatores específicos da escolha de área de atuação profissional de graduandos do curso de Terapia Ocupacional em duas instituições da cidade de Belo Horizonte/MG, de naturezas distintas (pública e privada). Foi aplicado um questionário a todos os formandos do segundo semestre de 2001, primeiro e segundo semestres de 2002 da UFMG e às duas turmas de formandos de 2001 e 2002 da FCMMG. Os dados obtidos foram analisados de forma quantitativa por meio de frequencia. Os resultados revelaram como fatores relevantes (peso acima de 7/10) para o processo de escolha: gosto, vocação, preparo, relação com profissionais, experiências práticas curriculares, qualificação docente, relação professor/aluno e consistência teórico-clínica da área. Os resultados apresentados podem contribuir para que os cursos compreendam as influências que exercem sobre os formandos e possam, a partir daí, criar estratégias para a resolução de problemas