A-Theory or B-Theory of Time? An Aristotelian Answer

A-Theory or B-Theory of Time? An Aristotelian Answer The purpose of this paper is to provide a description of Aristotle’s theory of time, in order to understand if it could introduce a stimulus into the contemporary debate on the nature of time between A-theorists and B-theorists. The first section (§1) of the paper is devoted to a conceptual explanation of these two main positions about the nature of time and their intimate link with eternalism and presentism. The second section (§2) presents the Aristotelian view on the nature of time (Strobach: 1998), considering his analysis on the notion of ‘periods’ (χρóνοι) and ‘instants’ or ‘nows’ (νυν) and arguing a metaphysical priority of the ‘now’ on the ‘period’. The third section (§3) tries to locate the Aristotelian theory into this contemporary debate, following two different strategies. Initially, it will be argued in favour of Aristotle present’s primacy demonstrating his preference for A-theory of time. Secondly, thorough the help of an argument from Jeffery Brower (2011), the paper provides an account of Aristotle’s position in a specific debate on the nature of time concerning the problem of ‘temporary intrinsics’, stating an Aristotelian endurantism. In the Conclusion, the paper claims the perfect consistency of Aristotle present’s primacy with Brower’s argument in favour of Aristotle’s endurantism. Bibliography Aristotle. (1995). Physic. Harvard University Press. Brower, J. (2011). Aristotelian Endurantism: A new Solution to the Problem of temporary Intrinsics. Mind 112: 882-905. Strobach, N. (1998). The Moment of Change. A Systematic History in the Philosophy of Space and Time. Springer-Science+Business Media, B.V. Key-words Aristotle – A-theory – B-theory – endurantism – metaphysics - perdurantis

Postoji li promjena prema B-teoriji vremena?

The purpose of this paper is to explore the connection between change and the B-theory of time, sometimes also called the Scientific view of time, according to which reality is a four-dimensional spacetime manifold, where past, present and future things equally exist, and the present time and non-present times are metaphysically the same. I argue in favour of a novel response to the much-vexed question of whether there is change on the B-theory or not. In fact, B-theorists are often said to hold a ‘static’ view of time. But this far from being innocent label: if the B-theory of time presents a model of temporal reality that is static, then there is no change on the B-theory. From this, one can reasonably think as follows: of course, there is change, so the B-theory must be false. What I plan to do in this paper is to argue that in some sense there is change on the B-theory, but in some other sense, there is no change on the B-theory. To do so, I present three instances of change: Existential Change, namely the view that things change with respect to their existence over time; Qualitative Change, the view that things change with respect to how they are over time; Propositional Change, namely the view that things (i.e. propositions) change with respect to truth value over time. I argue that while there is a reading of these three instances of change that is true on the B-theory, and so there is change on the B-theory in this sense, there is a B-theoretical reading of each of them that is not true on the B-theory, and therefore there is no change on the B-theory in this other sense.Svrha ovog rada je istražiti vezu između promjene i B-teorije vremena, koja se ponekad naziva i Znanstvenim pogledom na vrijeme, prema kojem je stvarnost četverodimenzionalni prostor-vremenski manifold, u kojem prošlost, sadašnjost i budućnost jednako postoje, a sadašnje vrijeme i ne-sadašnje vrijeme su metafizički isto. Argumentiram u prilog novom odgovoru na kompleksno pitanje postoji li promjena prema B-teoriji. Zapravo, često se kaže da B-teoretičari imaju ‘statični’ pogled na vrijeme. Međutim, ovo je daleko od nevine semantičke razlike: ako B-teorija vremena predstavlja model vremenske stvarnosti koji je statičan, tada prema B-teoriji nema promjena. Na temelju ovoga se razumno može smatrati sljedeće: naravno, promjena postoji, dakle B-teorija mora biti lažna. U ovom radu tvrdim da u jednom smislu postoji promjena prema B-teoriji, međutim u drugom smislu nema promjene prema B-teoriji. U tu svrhu predstavljam tri slučaja promjene: Egzistencijalna promjena, naime gledište da se stvari mijenjaju s obzirom na njihovo postojanje tijekom vremena; Kvalitativna promjena, gledište da se stvari mijenjaju s obzirom na njihovo postojanje tijekom vremena; Propozicijska promjena, naime gledište da se stvari (tj. propozicije) s vremenom mijenjaju u odnosu na njihovu istinosnu vrijednost. Tvrdim da, iako postoji interpretacija ove tri instance promjene koja je istinita prema B-teoriji, pa tako i promjena prema B-teoriji u tom smislu, postoji B-teorijska interpretacija svakog od njih koja nije istinita prema B-teoriji, stoga prema tome nema promjene prema B-teoriji u ovom drugom smislu

Is There Change on the B-theory of Time?

The purpose of this paper is to explore the connection between change and the B-theory of time, sometimes also called the Scientific view of time, according to which reality is a four-dimensional spacetime manifold, where past, present and future things equally exist, and the present time and non-present times are metaphysically the same. I argue in favour of a novel response to the much-vexed question of whether there is change on the B-theory or not. In fact, B-theorists are often said to hold a ‘static’ view of time. But this far from being innocent label: if the B-theory of time presents a model of temporal reality that is static, then there is no change on the B-theory. From this, one can reasonably think as follows: of course, there is change, so the B-theory must be false. What I plan to do in this paper is to argue that in some sense there is change on the B-theory, but in some other sense, there is no change on the B-theory. To do so, I present three instances of change: Existential Change, namely the view that things change with respect to their existence over time; Qualitative Change, the view that things change with respect to how they are over time; Propositional Change, namely the view that things (i.e. propositions) change with respect to truth value over time. I argue that while there is a reading of these three instances of change that is true on the B-theory, and so there is change on the B-theory in this sense, there is a B-theoretical reading of each of them that is not true on the B-theory, and therefore there is no change on the B-theory in this other sense

Design and Synthesis of Heterocycle‐Fused Enediyne Prodrugs Activable at Will

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Presentism and times as propositions

Some Presentists—according to whom everything is present—identify instants of time with propositions of a certain kind. However, the view that times are propositions seems to be at odds with Presentism: if there are times then there are past times, and therefore things that are past; but how could there be things that are past if everything is present? In this paper, we describe the Presentist view that times are propositions ; we set out the argument that Presentism is incompatible with the view that times are propositions ; and then we describe three possible responses to that argument on behalf of Presentists who identify times with propositions. We argue that each of these responses comes with significant costs. Finally, we describe a fourth possible response—according to which times are irreducibly higher-order entities—which appears to avoid the costs of the other three. We also describe and respond to two objections to the higher-order strategy

Analytical model of the acoustic response of nanogranular films adhering on a substrate

A 1D mechanical model for nanogranular films, based on a structural interface, is here presented. The analytical dispersion relation for the frequency and lifetimes of the acoustics breathing modes is obtained in terms of the interface layer thickness and porosity. The model is successfully benchmarked both against 3D Finite Element Method simulations and experimental photoacoustic data on a paradigmatic system available from the literature. A simpler 1D model, based on an homogenized interface, is also presented and its limitations and pitfalls discussed at the light of the more sophisticated pillar model. The pillar model captures the relevant physics responsible for acoustic dissipation at a disordered interface. Furthermore, the present findings furnish to the experimentalist an easy-to-adopt, benchmarked analytical tool to extract the interface layer physical parameters upon fitting of the acoustic data. The model is scale invariant and may be deployed, other than the case of granular materials, where a patched interface is involved

Pro-oxidant and pro-inflammatory effects of glycated albumin on cardiomyocytes.

Human serum albumin (HSA) is the most abundant circulating protein in the body and presents an extensive range of biological functions. As such, it is prone to undergo post-translational modifications (PTMs). The non-enzymatic early glycation of HSA, one of the several PTMs undergone by HSA, arises from the addition of reducing sugars to amine group residues, thus modifying the structure of HSA. These changes may affect HSA functions impairing its biological activity, finally leading to cell damage. The aim of this study was to quantitate glycated-HSA (GA) levels in the plasma of heart failure (HF) patients and to evaluate the biological effects of GA on HL-1 cardiomyocytes. Plasma GA content from HF patients and healthy subjects was measured by direct infusion electrospray ionization mass spectrometry (ESI-MS). Results pointed out a significant increase of GA in HF patients with respect to the control group (p < 0.05). Additionally, after stimulation with GA, proteomic analysis of HL-1 secreted proteins showed the modulation of several proteins involved, among other processes, in the response to stress. Further, stimulated cells showed a rapid increase in ROS generation, higher mRNA levels of the inflammatory cytokine interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α), and higher levels of the oxidative 4-HNE-protein adducts and carbonylated proteins. Our findings show that plasma GA is increased in HF patients. Further, GA exerts pro-inflammatory and pro-oxidant effects on cardiomyocytes, which suggest a causal role in the etiopathogenesis of HF

Extraction of antibacterial active compounds from dry leaves of African plants of the Combretaceae family

The dry leaves of two African plants of the Combretaceae family, furnished by the botanist of the St. Jean de Dieu hospital of Tangueita (Benin, central Africa),were extracted with a sequence of 5 solvents with increasing polarity (from cyclohexane to water).The raw materials, obtained from these extractions following solvent evaporations, were tested for antibiotic activity against gram negative and gram positive bacterial strains. According to the results of a modified Kirby-Bauer test, no promising effect was obtained against Gram negative bacteria while interesting dose-effect activities were observed against Gram positive strains. In particular, from G. senegalensis active compounds were found in the low polarity extract (dichloromethane) which, at a concentration of 800 μg/disk (13 mm diameter disk), resulted in a grow inhibition crown of 4.7 mm and 2.6 mm on Enterococcus faecalis and Staphylococcus aureus MSSA, respectively. An higher amount of the aqueous extract (4760 μg/disk) also produced a good result as 5.7 mm and 5.0 mm crowns were observed. The extracts from C. micranthum showed an inhibiting effect in the more polar extracts (i.e. from ethanol and water) which gave 1 mm of grow inhibition crown on both strains at a concentration of 1000 μg/disk. The most promising extract from each plant was partially purified and then tested on some clinical relevant bacterial strains: S. aureus MRSA, Clostridium difficile, Streptococcus pyogenes, Streptococcus pneumoniae, Corynebacterium striatum, Neisseria gonorrhoeae, Haemophylus influenzae, Escherichia coli, obtaining a good killing effects on the Gram positive bacteria of the panel

Photoacoustic Sensing of Trapped Fluids in Nanoporous Thin Films: Device Engineering and Sensing Scheme

Accessing fluid infiltration in nanogranular coatings is an outstanding challenge, of relevance for applications ranging from nanomedicine to catalysis. A sensing platform, allowing to quantify the amount of fluid infiltrated in a nanogranular ultrathin coating, with thickness in the 10 to 40 nm range, is here proposed and theoretically investigated by multiscale modelling. The scheme relies on impulsive photoacoustic excitation of hypersonic mechanical breathing modes in engineered gas-phase synthesised nanogranular metallic ultathin films and time-resolved acousto-optical read-out of the breathing modes frequency shift upon liquid infiltration. A superior sensitivity, exceeding 26x103 cm^2/g, is predicted upon equivalent areal mass loading of a few ng/mm^2. The capability of the present scheme to discriminate among different infiltration patterns is discussed. The platform is an ideal tool to investigate nano fluidics in granular materials and naturally serves as a distributed nanogetter coating, integrating fluid sensing capabilities. The proposed scheme is readily extendable to other nanoscale and mesoscale porous materials.Comment: 14 pages, 4 figure

Multicomponent Synthesis of Polyphenols and Their In Vitro Evaluation as Potential \u3b2-Amyloid Aggregation Inhibitors

While plant polyphenols possess a variety of biological properties, exploration of chemical diversity around them is still problematic. Here, an example of application of the Ugi multicomponent reaction to the combinatorial assembly of artificial, yet \u201cnatural-like\u201d, polyphenols is presented. The synthesized compounds represent a second-generation library directed to the inhibition of \u3b2-amyloid protein aggregation. Chiral enantiopure compounds, and polyphenol-\u3b2-lactam hybrids have been prepared too. The biochemical assays have highlighted the importance of the key pharmacophores in these compounds. A lead for inhibition of aggregation of truncated protein A\u3b2pE3-42 was selected