On the origin of the gravitational quantization: The Titius--Bode Law

Action at distance in Newtonian physics is replaced by finite propagation speeds in classical post--Newtonian physics. As a result, the differential equations of motion in Newtonian physics are replaced by functional differential equations, where the delay associated with the finite propagation speed is taken into account. Newtonian equations of motion, with post--Newtonian corrections, are often used to approximate the functional differential equations. In ``On the origin of quantum mechanics'', preprint, physics/0505181, May 2005, a simple atomic model based on a functional differential equation which reproduces the quantized Bohr atomic model was presented. The unique assumption was that the electrodynamic interaction has finite propagation speed. Are the finite propagation speeds also the origin of the gravitational quantization? In this work a simple gravitational model based on a functional differential equation gives an explanation of the modified Titius--Bode law.Comment: 9 pages, 1 figure in EPS forma

High-Speed Train Cell-less Network Enabled by XGS-PON and Impacts on vRAN Split Interface Transmission

We successfully demonstrate a transmission of a high layer split mobile interface for cell-less, high-speed train network applications using a commercially available XGS-PON. Operation is also demonstrated for a GbE interface

Moroccan propolis: a natural antioxidant, antibacterial, and antibiofilm against Staphylococcus aureus with no induction of resistance after continuous exposure

This study was performed to evaluate the total phenols, flavonoids, and antioxidant activities of twenty-four propolis samples from different regions of Morocco. In addition, two samples were screened regarding the antibacterial effect against four Staphylococcus aureus strains. Gas chromatography coupled to mass spectra (GC-MS) analysis was done for propolis samples used in antibacterial tests. The minimum inhibitory and minimum bactericidal concentration (MIC, MBC) were determined. The potential to acquire the resistance after sequential exposure of bacterial strains and the impact of adaptation to propolis on virulence using the Galleria mellonella were evaluated. Additionally, the effects of propolis extract on the bacterial adherence ability and its ability to inhibit the quorum sensing activity were also examined. Among the twenty-four extracts studied, the samples from Sefrou, Outat el Haj, and the two samples marketed in Morocco were the best for scavenging DPPH, ABTS, NO, peroxyl, and superoxide radicals as well as in scavenging of hydrogen peroxide. A strong correlation was found between the amounts of phenols, flavonoids, and antioxidant activities. Propolis extract at the MIC value (0.36 mg/mL) significantly reduced (p < 0.001) the virulence potential of S. aureus ATCC 6538 and the MRSA strains without leading to the development of resistance in the sequence of continuous exposure. It was able to impair the bacterial biofilm formation. The results have revealed that sample 1 reduces violacein production in a concentration dependent manner, indicating inhibition of quorum sensing. This extract has as main group of secondary metabolites flavonoids (31.9%), diterpenes (21.5%), and phenolic acid esters (16.5%).Fundacao para a Ciencia e a Tecnologia (FCT) - Pest-OE/QUI/UI4023/2011info:eu-repo/semantics/publishedVersio

A Luz a partir do campo e da part´Ä±cula de Higgs

In this contribution , the effort is to explain and discuss the central role of the Higgs field in the establishment of Electromagnetism in the Electroweak Unified Theory. Intrinsic properties as electrical charges and masses of charged particles ( leptons and quarks ) and the appearance of the vector boson with neutral zero mass , identified as the photon, emerge from the moment in which the Higgs field stabilizes the whole electroweak system and gives rise to the corresponding physical stimulation which is known as the Higg’s boson. The main idea is to show the leading role of such a boson in the constitution of the luminous phenomenon.Nesta contribui¸c˜ao, o esfor¸co consiste em explicitar e discutir o papel central do campo de Higgs no estabelecimento do setor eletromagn´etico na Teoria Unificada Eletrofraca. Propriedades intr´Ä±nsecas como as cargas el´etricas e as massas das part´Ä±culas carregadas (l´eptons e quarks) e o aparecimento do b´oson vetorial neutro de massa nula, identificado como o f´oton, emergem a partir do momento em que o campo de Higgs estabiliza todo o sistema eletrofraco e d´a origem `a excita¸c˜aof´Ä±sica correspondente ao b´oson de Higgs. A ideia principal ´e mostrar o preponderante papel do setor de Higgs na constitui¸c˜ao do fenˆomeno luminoso

O que é função? Debates na filosofia da biologia contemporânea

In this paper, we examine two very influential approaches to the nature of functional explanations/attributions: Wright's selectionist etiological approach and Cummins' functional analysis. The former seems to adequately grasp the meaning of several explanations in evolutionary biology, even though it is not sufficient to account for each and every evolutionary explanation. The latter, in turn, is more applicable to explanations in physiology and in other scientific areas dealing with complex systems. We see these two theories as distinct enterprises, which should not be combined in a single approach to functions. This leads us to support Godfrey-Smith's rejection of such a unity, in the form of his dualist consensus thesis. This thesis can be grounded on the distinction between evolutionary and functional biology, as sketched by Mayr and Jacob. We also address Cummins' critique of selectionist etiological approaches, which he labels as "neo-teleological". Although we consider that several criticisms raised by Cummins do identify flaws in these approaches, we intend to show that his attempt to reject neo-teleology as a whole is illegitimate. Criticisms from both sides of the debates about functions are contributing to enrich the comprehension of this central concept in Biology. These criticisms reinforce the need of delimiting the scope and limits of each approach, and, thus, point in the direction of a pluralism in the debate about functional explanations/attributions in the Philosophy of Biology.Neste artigo, examinamos duas abordagens bastante influentes sobre a natureza das atribuições/explicações funcionais: a abordagem etiológica selecionista de Wright e a análise funcional de Cummins. A primeira parece capturar de modo adequado o significado de várias explicações na biologia evolutiva, ainda que não dê conta de toda e qualquer explicação evolutiva. A segunda, por sua vez, é mais aplicável a explicações fisiológicas ou de outras áreas científicas que lidam com sistemas complexos. Entendemos as duas teorias como empreitadas distintas, que não devem ser combinadas em uma abordagem única sobre as funções. Isso nos leva a apoiar a rejeição de tal unidade por Godfrey-Smith, na forma de sua tese do consenso dualista. Esta tese pode ser ancorada na distinção entre biologia evolutiva e biologia funcional, esboçada por Mayr e Jacob. Tratamos também da crítica de Cummins às abordagens etiológicas selecionistas, as quais ele denomina "neoteleológicas". Embora consideremos que várias das críticas de Cummins de fato localizam falhas nessas abordagens, buscamos mostrar que sua tentativa de rejeição da neoteleologia como um todo é ilegítima. A partir das críticas de ambos os lados do debate sobre as funções, a compreensão desta noção central da biologia tem sido sobremaneira enriquecida. As críticas reforçam a necessidade de delimitar o escopo e o limite de cada uma das abordagens e, assim, apontam no sentido de um pluralismo no debate sobre atribuições/explicações funcionais na filosofia da biologia

Seleção de leveduras endofíticas do sorgo sacarino produtoras de enzimas hidrolíticas para produção de etanol e xilitol.

O objetivo deste trabalho foi avaliar e selecionar leveduras produtoras das enzimas hidrolíticas, amilase e celulase para futuramente avaliar seu potencial para produção de etanol e xilitol.Evento híbrido

Hierarchy Theory and its epistemological grounds

Hierarchy theory arose in the middle of the 1960s, as a result of a convergence from contributions of different disciplines that shared an interest for complexity, such as economy, chemistry, and biology. From the perspective of hierarchy theory, complexity is not considered either as a property of natural systems in themselves or as an exclusive property of the human mind, but rather as a property of questions posed by ourselves, as agents of knowledge, in the observational process. Complexity emerges, thus, in the relationship between natural systems and knowing subjects. This work carries out an analysis of the epistemological foundations of hierarchy theory, mainly addressing the possibility of grounding it in an anti-realist stance, such as van Fraassen’s constructive empiricism.A teoria das hierarquias emergiu, a partir de meados da década de 1960, como resultado de uma convergência de contribuições advindas de diversas disciplinas que compartilhavam à época um interesse pela complexidade, como economia, química e biologia. Da perspectiva da teoria das hierarquias, a complexidade não é considerada uma propriedade dos sistemas naturais em si mesmos e tampouco é concebida como uma propriedade exclusiva da mente humana, mas sim como uma propriedade das questões colocadas por nós, agentes do conhecimento, no processo de observação. A complexidade emerge, pois, na relação entre os sistemas naturais e os sujeitos cognoscentes. Este trabalho realiza uma análise dos fundamentos epistemológicos da teoria das hierarquias, tratando, sobretudo, da possibilidade de embasá-la numa visão anti-realista, como o empirismo construtivo de van Fraasse