17,407 research outputs found
Defining Original Presentism
It is surprisingly hard to define presentism. Traditional definitions
of the view, in terms of tensed existence statements, have
turned out not to to be capable of convincingly distinguishing
presentism from eternalism. Picking up on a recent proposal
by Tallant, I suggest that we need to locate the break between
eternalism and presentism on a much more fundamental level.
The problem is that presentists have tried to express their
view within a framework that is inherently eternalist. I call
that framework the Fregean nexus, as it is defined by Frege’s
atemporal understanding of predication. In particular, I show
that the tense-logical understanding of tense which is treated
as common ground in the debate rests on this very same
Fregean nexus, and is thus inadequate for a proper definition
of presentism. I contrast the Fregean nexus with what I call
the original temporal nexus, which is based on an alternative,
inherently temporal form of predication. Finally, I propose
to define presentism in terms of the original temporal nexus,
yielding original presentism. According to original presentism,
temporal propositions are distinguished from atemporal ones not
by aspects of their content, as they are on views based on the
Fregean nexus, but by their form—in particular, by their form of
predication
Robots and us: towards an economics of the ‘Good Life’
(Expected) adverse effects of the ‘ICT Revolution’ on work and opportunities for
individuals to use and develop their capacities give a new impetus to the debate on the
societal implications of technology and raise questions regarding the ‘responsibility’ of
research and innovation (RRI) and the possibility of achieving ‘inclusive and sustainable
society’. However, missing in this debate is an examination of a possible conflict
between the quest for ‘inclusive and sustainable society’ and conventional economic
principles guiding capital allocation (including the funding of research and innovation).
We propose that such conflict can be resolved by re-examining the nature and purpose
of capital, and by recognising mainstream economics’ utilitarian foundations as an
unduly restrictive subset of a wider Aristotelian understanding of choice
Changes and Problems of Agricultural Development in Iran
There has been a big debate on the evolution of agricultural development (AD), the challenges and problems hindering AD in Iran since last decade. This study was implemented in the province of Esfahan and a number of 130 out of 212 agricultural experts from 13 different townships were selected as the target group. Totally 70 experts returned the completed questionnaires. The findings of the study revealed that most of the AD changes have been positive but in a very slow rate. Respondents unanimously claimed that the sustainability in agriculture and maintenance of agricultural lands are the most deteriorating issues during last ten years. With regard to AD problems, they stressed the lack of adequate fund allocated to the Ministry of Agriculture (MAJ) and lack of its power to control beneficiary dealers within the sector, unfair political influence, lack of international contacts and also untrustworthiness of agriculture for private investors as the most problematic obstacles for AD in Iran. They perceived that MAJ has not sufficiently addressed the problems so far, although, there are some promising movements. Experts believed that MAJ is not able to solve the majority of problems alone due to their extrinsic nature
Confinement and crowding control the morphology and dynamics of a model bacterial chromosome
Motivated by recent experiments probing shape, size and dynamics of bacterial
chromosomes in growing cells, we consider a polymer model consisting of a
circular backbone to which side-loops are attached, confined to a cylindrical
cell. Such a model chromosome spontaneously adopts a helical shape, which is
further compacted by molecular crowders to occupy a nucleoid-like subvolume of
the cell. With increasing cell length, the longitudinal size of the chromosome
increases in a non-linear fashion to finally saturate, its morphology gradually
opening up while displaying a changing number of helical turns. For shorter
cells, the chromosome extension varies non-monotonically with cell size, which
we show is associated with a radial to longitudinal spatial reordering of the
crowders. Confinement and crowders constrain chain dynamics leading to
anomalous diffusion. While the scaling exponent for the mean squared
displacement of center of mass grows and saturates with cell length, that of
individual loci displays broad distribution with a sharp maximum.Comment: 12 pages, 12 figure
Cubatic phase for tetrapods
We investigate the phase behavior of tetrapods, hard non-convex bodies formed
by 4 rods connected under tetrahedral angles. We predict that, depending on the
relative lengths of the rods these particles can form a uniaxial nematic phase,
and more surprisingly they can exhibit a cubatic phase, a special case of the
biaxial nematic phase. These predictions may be experimentally testable, as
experimental realizations of tetrapods have recently become available.Comment: 8 pages ReVTeX 4, including 3 EPS figure
Improved procedure for determining the ductility of buildings under seismic loads
Displacement ductility is a parameter that characterizes the seismic response of structures. Moreover, displacement ductility can be used in order to determine whether a structural design, performed according to a specific seismic code or not, may achieve the main goal of the seismic design: to develop energy dissipation in a stable manner. Determination of displacement ductility is not an easy task, because the structural response usually does not show a clear location of the points that define yield and ultimate displacements. In this paper, some of the main procedures for ductility displacement are revised and compared, and then improvements are performed to such procedures in order to compute the displacement ductility. A new procedure is then introduced, leading to determine the ultimate displacement using the seismic collapse threshold and the yield displacement, achieving the balance of dissipated energy. The procedure has been used to calculate displacement ductility of reinforced concrete framed buildings.Peer Reviewe
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