Osteosarcoma is the most common primary bone cancer. According to medical and biological studies, it has a high genetic complexity, thus, to differentiate the mechanisms of appearance and evolution of this disease is a difficult task. In this paper, we use three simplest and well known mathematical models to describe the behavior of several cell lines of osteosarcoma. First, we use a potential law to describe the tumor growth in immunosuppressed mice; with it we show that the variation of tumor (...) growth has a sublinear behavior without the blow-up phenomenon. Second, the logistic model is used to obtain a good aproximation to the rates of proliferation in cell confluency in in vitro experiments. Third, we use a linear reaction-diffusion model; with it, we describe the diffusion behavior for some cell lines. These three models allow us to give a classification of cell lines according to the rates of tumor growth and proliferation and to the diffusion coefficient. A relationship is found between the rates of the tumor growth, the diffusion coefficient and tumorigenicity. Experimental data are extracted from Lauvrak et al. (British Journal of Cancer 109(8):2228–2236, 2013). (shrink)

Debates about the genuine disease status of controversial diseases rely on intuitions about a range of factors. Adopting tools from experimental philosophy, this paper explores some of the factors that influence judgments about whether low sexual desire should be considered a disease and whether it should be medically treated. Drawing in part on some assumptions underpinning a divide in the literature between viewing low sexual desire as a genuine disease and seeing it as improperly medicalized, we investigate whether health and (...) disease judgments are affected by factors such as an individual’s gender, the cause of the low desire, whether the desire is high or low, and both personal and societal valuations of the condition. Our main findings indicate that (a) the cause of a condition influences whether it is judged a disorder, (b) how the individual values the condition influences whether the condition is seen as a proper target of medical intervention, and (c) perceived dysfunction influences judgments regarding health, disorder classification, medicalization, and medical intervention. Our findings help further illuminate the intricate interplay of factors that influence judgments about health and disease in controversial conditions. (shrink)

After reviewing the foundations of special relativity and the room left for rival theories, a set of nonrelativistic para-Lorentzian transformations is derived uniquely, based on (a) a weaker first principle, (b) the requirement that the transformations sought do not give rise to the clock “paradox” (in a refined version), and (c) the compliance of the transformations with the classical experiments of Michelson-Morley, Kennedy-Thorndike, and Ives-Stilwell. The corresponding dynamics is developed. Most of the experimental support of special relativity is reconsidered in (...) the light of the new theory. It is concluded that the relativity of simultaneity has so far not been tested. (shrink)

In a recent paper [J. G. Vargas and D. G. Torr, Found. Phys. 27, 599 (1997)], we have shown that a subset of the differential invariants that define teleparallel connections in spacetime generates a teleparallel Kaluza-Klein space (KKS) endowed with a very rich Clifford structure. A canonical Dirac equation hidden in this structure might be uncovered with the help of a teleparallel Kähler calculus in KKS. To bridge the gap to such a calculus from the existing Riemannian Kähler calculus (...) in spacetime, we commence the construction of a teleparallel Kähler calculus in spacetime. In the process, we notice: (a) Unknown to him, one of Einstein's equations in his attempt at unification with teleparallelism states that the interior covariant derivative of the torsion is zero. (b) A mechanism exists in the tangent bundle of teleparallel spaces for producing confinement (in the applicable cases, one would have to show why nonconfinement also occurs, rather than the other way around). (c) When the torsion is not zero, the interior covariant derivative in the sense of Kähler, δF, does not coincide with *d*F. The system (dF = 0, δF = j) rather than (dF = 0, *d*F = j) should then be used for generalizations of Maxwell's electrodynamics. (shrink)

A connection viewed from the perspective of integration has the Bianchi identities as constraints. It is shown that the removal of these constraints admits a natural solution on manifolds endowed with a metric and teleparallelism. In the process, the equations of structure and the Bianchi identities take standard forms of field equations and conservation laws.The Levi-Civita (part of the) connection ends up as the potential for the gravity sector, where the source is geometric and tensorial and contains an explicit gravitational (...) contribution.Nonlinear field equations for the torsion result. In a “low-energy” approximation (linearity andlow energy-momentumtransfer), the postulate that only charge and velocities contribute to the source transforms these equations into the Maxwell system. Moreover, the affine geodesics become the equations of motion of special relativity with Lorentz force in the same approximation [J. G. Vargas,Found. Phys. 21, 379 (1991)]. The field equations for the torsion must then be viewed as applying to an electromagnetic/strong interaction.A classical unified theory thus arises where the underlying geometry confers their contrasting characters to Maxwell-Lorentz electrodynamics and to an Einstein's-like theory of gravity. The highly compact field equations must, however, be developed in phase-spacetime, since the connection is velocity-dependent, i.e., Finsler-like.Further opportunities for similarities with present-day physics are discussed: (a) teleparallelism allows for the formulation of the torsion sector of the theory as a flat space theory with concomitant point-dependent transformations; (b) spinors should replace Lorentz frames in their role as the subjects to which the connection refers; (c) the Dirac equation consistent with the frame bundle for a velocity-dependent metric with Lorentz signature generates a weak-like interaction in the torsion sector. (shrink)

© 2017. The American Astronomical Society. All rights reserved.We present new observations of the low-mass companion to HD 984 taken with the Gemini Planet Imager as a part of the GPI Exoplanet Survey campaign. Images of HD 984 B were obtained in the J and H bands. Combined with archival epochs from 2012 and 2014, we fit the first orbit to the companion to find an 18 au orbit with a 68% confidence interval between 14 and 28 au, an eccentricity (...) of 0.18 with a 68% confidence interval between 0.05 and 0.47, and an inclination of 119°with a 68% confidence interval between 114°and 125°. To address the considerable spectral covariance in both spectra, we present a method of splitting the spectra into low and high frequencies to analyze the spectral structure at different spatial frequencies with the proper spectral noise correlation. Using the split spectra, we compare them to known spectral types using field brown dwarf and low-mass star spectra and find a best-fit match of a field gravity M6.5 ±1.5 spectral type with a corresponding temperature of K. Photometry of the companion yields a luminosity of log=2.88 ± 0.07 dex with DUSTY models. Mass estimates, again from DUSTY models, find an age-dependent mass of 34 ±1 to 95 ±4 M Jup. These results are consistent with previous measurements of the object. (shrink)

We present a one per cent measurement of the cosmic distance scale from the detections of the baryon acoustic oscillations in the clustering of galaxies from the Baryon Oscillation Spectroscopic Survey, which is part of the Sloan Digital Sky Survey III. Our results come from the Data Release 11 sample, containing nearly one million galaxies and covering approximately 8500 square degrees and the redshift range 0.2 < z < 0.7. We also compare these results with those from the publicly released (...) DR9 and DR10 samples. Assuming a concordance Λ cold dark matter cosmological model, the DR11 sample covers a volume of 13 Gpc3 and is the largest region of the Universe ever surveyed at this density. We measure the correlation function and power spectrum, including density-field reconstruction of the BAO feature. The acoustic features are detected at a significance of over 7σ in both the correlation function and power spectrum. Fitting for the position of the acoustic features measures the distance relative to the sound horizon at the drag epoch, rd, which has a value of rd,fid = 149.28 Mpc in our fiducial cosmology. We find DV = at z = 0.32 and DV = at z = 0.57. At 1.0 per cent, this latter measure is the most precise distance constraint ever obtained from a galaxy survey. Separating the clustering along and transverse to the line of sight yields measurements at z = 0.57 of DA = and H =. Our measurements of the distance scale are in good agreement with previous BAO measurements and with the predictions from cosmic microwave background data for a spatially flat CDM model with a cosmological constant. © 2014 The Author Published by Oxford University Press on behalf of the Royal Astronomical Society. (shrink)

In recent years, animal welfare has become an important element of sustainable production that has evolved along with the transformation of animal production systems. Consumer attitudes towards farm animal welfare are changing around the world, especially at emerging markets of Asia, Africa and Latin America. Survey-based research on consumer attitudes towards farm animal welfare has increased. However, the geographical coverage of studies on consumer attitudes and perceptions about farm animal welfare has mostly been limited to Europe, and North America. Until (...) now, Latin American consumers’ attitudes towards animal welfare have not been well studied. Despite the fact that Mexico, Chile and Brazil belong to the same region, there are marked differences between these countries in terms of their economical and geographical characteristics among other factors. Those differences potentially have an impact on consumer attitudes towards animal welfare and livestock production systems in general. Given the evidence from the literature review, it seems advisable that Latin American producers and food industry who engage in animal welfare-enhancing practices should clearly label their products with information on the type of husbandry system to reach those consumers who want to make an informed choice. Therefore, there are some aspects that need to be studied and cannot be worked separately in order to promote and understand consumer attitudes towards dairy and beef systems, such as geography, economic development, and politics. (shrink)

While philosophical questions about health and disease have attracted much attention in recent decades, and while opinions are divided on most issues, influential accounts seem to embrace negativism about health, according to which health is the absence of disease. Some subscribe to unrestricted negativism, which claims that negativism applies not only to the concepts of health and disease as used by healthcare professionals but also to the lay concept that underpins everyday thinking. Whether people conceptualize health in this manner has (...) implications for medical care and public health, and so we set out to examine this claim in two studies. Participants were asked to assess and compare the health states of two people presented in two vignettes. We found that both lay people and medical students conceptualize health as something more than the absence of disease. We argue that our findings highlight a need to rethink unrestricted negativism and indicate a need to rethink the way the debate has traditionally focused on disease. (shrink)

Prior research has unveiled a pathologization effect where individuals perceived as having bad moral character are more likely to have their conditions labeled as diseases and are less often considered healthy compared to those viewed as having a good moral character. Moreover, these individuals are perceived as less unlucky in their affliction and more deserving of it. This study explores the broader impacts of moral character on such judgments, hypothesizing that these effects reach deeper and extend to both negative and (...) positive moral evaluations. The pathologization effect also raises concerns about potential discrimination and the overmedicalization of normal health variations, so we also examine whether providing more detailed descriptions of conditions mitigates the influence of judgments of moral character. The methodology and broader implications of our findings are discussed, emphasizing the need for a deeper understanding of how moral judgments might influence patient care. (shrink)

A good argument is one whose conclusions follow from its premises; its conclusions are consequences of its premises. But in what sense do conclusions follow from premises? What is it for a conclusion to be a consequence of premises? Those questions, in many respects, are at the heart of logic (as a philosophical discipline). Consider the following argument: 1. If we charge high fees for university, only the rich will enroll. We charge high fees for university. Therefore, only the rich (...) will enroll. There are many different things one can say about this argument, but many agree that if we do not equivocate (if the terms mean the same thing in the premises and the conclusion) then the argument is valid, that is, the conclusion follows deductively from the premises. This does not mean that the conclusion is true. Perhaps the premises are not true. However, if the premises are true, then the conclusion is also true, as a matter of logic. This entry is about the relation between premises and conclusions in valid arguments. (shrink)

How do people understand the concepts of mental health and disorder? The objective of this paper is to examine the impact of several factors on people’s judgments about whether a condition constitutes a mental disorder or a healthy state. Specifically, this study examines the impact of the source of the condition, its outcome, individual valuation (i.e., the value the individual attaches to the condition), and group valuation (i.e., the value the relevant group attaches to the condition). While we find that (...) people’s health and disorder judgments are driven by perceived dysfunction, we also find that health and disorder judgments are impacted differently by these factors. Health judgements are impacted by outcome and individual valuation, and disorder judgments are impacted by condition source. These results suggest that the folk concept of mental health is positive (i.e., mental health is more than the absence of mental disorder) and normativist (i.e., value judgments play a significant role in determining whether a condition counts as healthy), while the concept of mental disorder aligns with a naturalist perspective, at least to the extent that dysfunction plays an important role in categorizing a condition as a disorder. However, our finding that people’s dysfunction judgments are influenced by individual valuation and outcomes poses a strong challenge to naturalist accounts. To provide access to our supplementary data, an appendix has been included. (shrink)

Fenómenos contemporáneos en torno a la visibilización de los autores y sus obras, y relacionados con las responsabilidades de los diversos agentes en el campo literario, ponen sobre la mesa una y otra vez preguntas a propósito de los mecanismos y las expectativas del ejercicio de lectura crítica por parte de los lectores. El presente artículo se propone explicitar los rendimientos descriptivos y normativos que para dicho ejercicio ofrece el concepto de resonancia, propuesto por Hartmut Rosa en el seno de (...) su sociología crítica de la vida buena. La pregunta rectora reza: ¿de qué manera la idea de un vínculo resonante con la obra enriquece la comprensión y modelización de la lectura crítica? Para responder a ello, el artículo expone en primer lugar el concepto de resonancia; a continuación, ilustra tres formas de relación con la obra mediante analogías con los casos retratados en el documental Grizzly Man de Werner Herzog, en la novela Rayuela de Julio Cortázar y en el cuento “Ficción” de Alice Munro. Finalmente, a modo de respuesta, se plantea la tesis de que la teoría de la resonancia permite conceptualizar la agencia (deseable) del lector en términos de una mediopasividad o medioactividad que involucra tanto la exposición a diferentes instancias de mediación como la materialización de un juicio crítico-ético sobre la obra, en la estela de Wayne C. Booth. (shrink)

In order to understand the rise of runaway solutions in the radiation reaction problem a mechanical model is used. An alternative demonstration of Daboul’s theorem, through Hurwitz’s criterion, is given. The origin of runaway solutions in electrodynamics is discussed. They arise when the particle has a negative mechanical mass or when approximations are used in the equation of motion. In the 1-dimensional mechanical model an exact and linear equation of motion for the particle is obtained, the corresponding exact solution is (...) again runaway when the mechanical mass is negative. The exact solution is not runaway when the mechanical mass is positive. However, the use of approximations leads to an equation of motion which has runaway solutions. It is exhibited that the use of approximations in the 3-dimensional mechanical model is completely necessary because the general equation of motion for the particle is non-linear. The analysis of this case proceeds in a very similar way to the one carried out in electrodynamics. This means that the number of dimensions also plays an important role in the analysis. (shrink)

Este artículo presenta la cuestión de si las creencias religiosas son o no razonables, es decir, si tienen o no una evidencia razonable que las sustente. El interés no es comprobar la existencia de Dios, sino simplemente saber si el lenguaje religioso como tal tiene o no sentido. Para esto, primero veremos la concepción de la creencia en general. A continuación, trataremos las creencias religiosas bajo dos puntos de vistas totalmente opuestos: por un lado, se expondrá la posición de autores (...) que dicen que las creencias religiosas sí tienen una evidencia razonable que las sustenta y, por otro, nos encontraremos con autores que afirman que dichas creencias no pueden ser justificadas racionalmente porque lo espiritual refiere el ámbito de lo indecible, en el cual no es factible afirmar que los enunciados religiosos son apropiados a ser verdaderos o falsos. (shrink)

I examine the extent to which Dennett’s account in Freedom Evolves might be construed as revisionist about free will or should instead be understood as a more traditional kind of compatibilism. I also consider Dennett’s views about philosophical work on free agency and its relationship to scientific inquiry, and I argue that extant philosophical work is more relevant to scientific inquiry than Dennett’s remarks may suggest.

A historiografia neo-republicana de Cambridge estabeleceu uma franca distinção entre republicanismo e liberalismo que merece ser reexaminada. Este artigo busca contribuir para esse debate, propondo um estudo de caso dos commonwealthmen ou republicanos que apoiaram a revolução de 1688 na Inglaterra, mas que se opuseram à nova cultura política e à nova “economia de crédito” do reino de Guilherme III na década de 1690. Ao desviarmos nosso olhar do republicanismo enquanto linguagem para situá-lo sob o republicanismo enquanto cultura, bem como (...) modo de ação política, é possível constatar uma porosidade entre direitos naturais e virtude cívica, mas também entre liberdade negativa e liberdade positiva. (shrink)

For any given society, its particular technology of communication has far-reaching consequences, not merely as regards social organization, but on the epistemic level as well. Plato's name-theory of meaning represents the transition from the age of primary orality to that of literacy; Wittgenstein's use-theory of meaning stands for the transition from the age of literacy to that of a second orality (audiovisual communication, electronic information processing). On the basis of a use-theory of meaning the problem of machine consciousness, to which (...) the later Wittgenstein again and again returned, is capable of a non-essentialist solution: appropriate changes in our form of life might well entail a radically different psychological language-game. (shrink)

A large part of the contemporary literature on dehumanization is committed to three ideas: (a) dehumanization involves some degree of denial of humanness, (b) such denial is to be comprehended in mental terms, and (c) whatever exact mechanisms underlie the denial of humanness, they belong in the realm of post-perceptual processing. This chapter examines (c) and argues that the awareness of minds might belong to perceptual processing. This paves the way for the possibility that dehumanization might, at least in part, (...) be a perceptual phenomenon, such that dehumanizers visually perceive the dehumanized as exhibiting lesser-than-human minds. It is perhaps unsurprising that the first systematic investigations of dehumanization approached the phenomenon as linked to contexts of war, genocide, extreme hatred, and violence. One guiding hypothesis was that dehumanizers exclude the dehumanized from a moral community of human beings, implicitly conceptualized as displaying distinct individualities and being embedded in caring interpersonal relations. By comprehending the dehumanized as deindividuated entities to which moral norms and considerations of fairness do not apply (Opotow 1990), dehumanizers are able to disengage from moral restrictions and self-sanctions (Bandura 1999). (shrink)

Philosophical accounts denying that temporal passage is an objective feature of reality face an explanatory challenge with respect to why it appears to us as though time passes. Recently, two solutions have surfaced. Cognitive illusionism claims that people experience the passage of time due to their belief that time passes. Cognitive error theory claims that we do not experience the passage of time, but hold the belief that we do, which we have acquired through making an inference from the prior (...) belief that time passes. These approaches suppose that belief and passage experience are explanatorily connected, and they depend on the claims that people who experience the passage of time or at least believe that they do also believe that time passes. To test these claims, we probed the beliefs of populations of individuals with depression and schizotypy, thus conditions that are strongly associated with alterations in temporal phenomenology. Depression was assessed with the Beck Depression Inventory (BDI) and schizotypy with the short Oxford-Liverpool Inventory of Feelings and Experiences (O-LIFE). While cognitive illusionism and inferentialist cognitive error theory would predict a strong association between BDI and O-LIFE scores and beliefs about time passage, our study found no such association. The experience of passage does not seem to be explanatorily connected to beliefs about the passage of time. (shrink)

In the midst of recent ethical decision-making failures in business in the past ten or more years, businesses are beginning to prioritize the moral fiber of their new-hire business graduates. In addition to academic performance, intellectual drive, and personality match, perhaps there are other key characteristics that employers seek which speak to the importance of ethical decision makers in practice. The question remains, how can academic institutions help instill such values into their students so that ethical decision making transcends their (...) lives? This article suggests that experiential learning through an institutional-sponsored business forum can help enhance an individual’s self-efficacy and awareness of the school’s value-based education, which ultimately will lead students towards ethical decision making in practice. Five years of survey data collected at business forum events suggests that business forums are making a difference in the students’ self-assessed abilities to show greater self-efficacy, better ethical decision making, and an increased awareness of their institution’s value-based education. Specifically, data collected illustrate a mediating effect of self-efficacy and awareness of a value-based education en route to ethical decision making. Further, support is found for the primary hypothesis that attendance at business forums does result in a higher propensity to make ethical decisions. Because of these positive findings, higher education institutions looking to place a greater emphasis on the ethical leadership of their business students may want to explore adding such experiential learning programs. (shrink)