3,362 research outputs found
Pietro Verri’s Contribution to the Economic Theory of the 18th Century: Commercial Society, Civil Society and Governance of the Economy
No full text'Count Pietro Verri (1728-97) - Schumpeter writes (History, p. 178) - - would have to be included in any list of the greatest economists'. Within the Milanese school, he certainly stands out, alongside with Cesare Beccaria, during one of the most interesting periods from a history of analysis point of view. Luigi Cossa's famous introduction to the study of political economy rates Pietro Verri to be inferior to Beccaria in ingenuity and scientific cultivation, but greatly to be ahead of him as an economist.1 This judgement by Cossa, in particular, seems to echo the relative position of the two men in the history of ideas, particularly after Beccaria's rise to fame with a book - On crimes and punishments - which had in fact been largely inspired by Verri himself and defended by him.2 It is proposed in the present paper to revisit some of the basic tenets of Pietro Verri's political economy, with more in view than dwell on specific intuitions and theorems: namely relate those to Verri's own - quite original - conception of the economy. The scholarly work of Pietro Verri - with a special reference to his Meditazioni sulla economia politica of 1771 - provides the first systematic contribution stemming from the quarters of Lombard enlightenment in the field of political economy, especially so if one considers that Cesare Beccaria's parallel work - namely his Elementi di economia pubblica, conceived and drafted at the same time as Verri's Meditazioni - would only be published posthumously several years later. From the vantage point afforded by Verri's political economy, we gain a considerably attractive view of the most significant elements and characteristic concepts of Lombard enlightenment during the latter half of the 18th century; Verri, moreover, as we shall see, builds on a number of them in a new and original way. This paper is aimed at discussing Verri's political economy mainly along two distinct, but related, lines. In the first place the conception of commercial society is considered such as it is treated by the author particularly in his Meditazioni. In this perspective the analysis of such issues as competition and the market or money and taxation occupy a central place. Secondly it will be necessary to emphasise that Verri's approach has little to do either with forms of pure economics on one side - largely yet to be born throughout the 18th century - or, on the other side, with such conceptions of the polis - contrariwise well alive among his own contemporaries - as are founded on a sovereign authority conceived to be situated above the law. What Verri's political economy ultimately amounts to is an economic conception of civil society. The latter has natural strong connections with his own fact-mindedness - emphasised by Schumpeter - as well as with his deep practical involvement in administrative affairs and in the reforming process taking place during the latter half of the 18th century in Milan. In our view, a thorough investigation along the mentioned lines is the precondition for an understanding of the intellectual stature and of the scholarly contribution of Pietro Verri. His main ground is distinctly analytical and only by appreciating his analysis is it possible to shed light on the meaning and intellectual significance also of his practical contributions. Moreover Verri's pronouncements on the criticism of despotic government, the relevance of intermediate powers or bodies and on multiple levels of governance will be examined in a new and original light, showing how close they are to the gist of his analysis.
About twin primes and distribution of primes
No full textThis paper give us a demonstration of twin primes conjecture using approximation of function �(iupsilon) that we introduce in section 6. Section 1-5 give us introduction to terminology and a clarification on (iupsilon) terms. In particular section
5 is really important because of its Lemma. Section 7 reassume foregoing explanations and it give us two theorems and one corollary;the theorem 7.2 give us exact approximation of twin primes counting function
Dissipative quantum transport in macromolecules: Effective field theory approach
No full textWe introduce an atomistic approach to the dissipative quantum dynamics of charged or neutral excitations
propagating through macromolecular systems. Using the Feynman-Vernon path integral formalism, we
analytically trace out from the density matrix the atomic coordinates and the heat bath degrees of freedom.
This way we obtain an effective field theory which describes the real-time evolution of the quantum excitation
and is fully consistent with the fluctuation-dissipation relation. The main advantage of the field-theoretic approach
is that it allows us to avoid using the Keldysh contour formulation. This simplification makes it straightforward
to derive Feynman diagrams to analytically compute the effects of the interaction of the propagating quantum
excitation with the heat bath and with the molecular atomic vibrations. For illustration purposes, we apply this
formalism to investigate the loss of quantum coherence of holes propagating through a poly(3-alkylthiophene)
polymer
Predicting Charge Mobility of Organic Semiconductors with Complex Morphology
No full textWe introduce a mesoscopic model to
predict the charge mobility of organic semiconductors characterized
by a coexistence of crystalline and amorphous phases. First, we validate
our scheme by reproducing the trends in charge mobility observed in
thin films of poly(3-hexylthiophene) (P3HT) polymers. Next, we address
the problem of predicting the morphologies that lead to the highest
mobility. Our main finding is the identification of a region of the
model’s multidimensional parameter space, in which the charge
mobility effectively depends on a single morphological feature: the
average intercrystallite distance. This scaling behavior provides
insight into the main physical mechanism limiting charge mobility
in organic semiconductors. Our proposed framework can be adapted to
study a wide class of polymeric systems and used to guide the manufacturing
of new, high-performing organic semiconductor materials
RNA folding pathways from all-atom simulations with a variationally improved history-dependent bias
No full textAtomically detailed simulations of RNA folding have proven very challenging in view of the difficulties of developing realistic force fields and the intrinsic computational complexity of sampling rare conformational transitions. As a step forward in tackling these issues, we extend to RNA an enhanced path-sampling method previously successfully applied to proteins. In this scheme, the information about the RNA's native structure is harnessed by a soft history-dependent biasing force promoting the generation of productive folding trajectories in an all-atom force field with explicit solvent. A rigorous variational principle is then applied to minimize the effect of the bias. Here, we report on an application of this method to RNA molecules from 20 to 47 nucleotides long and increasing topological complexity. By comparison with analog simulations performed on small proteins with similar size and architecture, we show that the RNA folding landscape is significantly more frustrated, even for relatively small chains with a simple topology. The predicted RNA folding mechanisms are found to be consistent with the available experiments and some of the existing coarse-grained models. Due to its computational performance, this scheme provides a promising platform to efficiently gather atomistic RNA folding trajectories, thus retain the information about the chemical composition of the sequence
Unfolding Thermodynamics of Cysteine-Rich Proteins and Molecular Thermal-Adaptation of Marine Ciliates
No full textEuplotes nobilii and Euplotes raikovi are phylogenetically closely allied species of marine ciliates, living in polar and temperate waters, respectively. Their evolutional relation and the sharply different temperatures of their natural environments make them ideal organisms to investigate thermal-adaptation. We perform a comparative study of the thermal unfolding of disulfide-rich protein pheromones produced by these ciliates. Recent circular dichroism (CD) measurements have shown that the two psychrophilic (E. nobilii) and mesophilic (E. raikovi) protein families are characterized by very different melting temperatures, despite their close structural homology. The enhanced thermal stability of the E. raikovi pheromones is realized notwithstanding the fact that these proteins form, as a rule, a smaller number of disulfide bonds. We perform Monte Carlo (MC) simulations in a structure-based coarse-grained (CG) model to show that the higher stability of the E. raikovi pheromones is due to the lower locality of the disulfide bonds, which yields a lower entropy increase in the unfolding process. Our study suggests that the higher stability of the mesophilic E. raikovi phermones is not mainly due to the presence of a strongly hydrophobic core, as it was proposed in the literature. In addition, we argue that the molecular adaptation of these ciliates may have occurred from cold to warm, and not from warm to cold. To provide a testable prediction, we identify a point-mutation of an E. nobilii pheromone that should lead to an unfolding temperature typical of that of E. raikovi pheromones
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