2,524 research outputs found
In search of liberal Tsarism: the historiography of autocratic decline
The idea that the autocracy might have successfully modernized itself has, in recent years, spread widely beyond academic circles. However, a look at traditional and recent historiography shows that very few historians support this line. Even those who argue that Russia itself was developing rapidly have seen little prospect of the autocracy surviving the process. Equally, those who argue that radical socialist revolution might have been avoided tend to suggest, often by implication rather than in an explicit fashion, that a democratic, capitalist, bourgeois, and constitutional revolution was the alternative path. Thus it was not so much a question of tsarism or revolution but rather what kind of revolution was Russia facing
Causation: Philosophy of Science
In The Critique of Pure Reason (first published in 1781), the German philosopher Immanuel Kant maintained that causation was one of the fundamental concepts that rendered the empirical world comprehensible to humans. By the beginning of the twenty-first century, psychology was beginning to show just how pervasive human reasoning concerning cause and effect is. Even young children seem to naturally organize their knowledge of the world according to relations of cause and effect.
It is hardly surprising, then, that causation has been a topic of great interest in philosophy, and that many philosophers have attempted to analyze the relationship between cause and effect. Among the more prominent proposals are the following: Causation consists in the instantiation of exceptionless regularities (Hume 1975, 1999; Mill1856; Hempel1965; Mackie 1974); causation is to be understood in terms of relations of probabilistic dependence (Reichenbach 1956, Suppes 1970, Cartwright 1983, Eells 1991); causation is the relation that holds between means and ends (Gasking 1955, von Wright 1975, Woodward 2003); causes are events but for which their effects would not have happened (Lewis 1986); causes and effects are connected by physical processes that are capable of transmitting certain types of properties (Salmon 1984, Dowe 2000).
It often happens, however, that advances in science force people to abandon aspects of their common sense picture of the world. For example, Einstein's theories of relativity have forced people to rethink their conceptions of time, space, matter, and energy. What lessons does science teach about the concept of causation
Global changes, local impacts: California\u27s adaptation tools help its cities address climate change
The State of California has been changing state-level policies and legislation to prepare for and minimize the impacts of climate change. But how can local governments integrate climate adaptation planning into local policy and practice? Through three-case studies, Boswell and Read discuss how state agencies and the robust set of tools and guidance in the California Adaptation Planning Guide have been helping California communities in climate action planning
Photoionization of Galactic Halo Gas by Old Supernova Remnants
We present new calculations on the contribution from cooling hot gas to the
photoionization of warm ionized gas in the Galaxy. We show that hot gas in
cooling supernova remnants (SNRs) is an important source of photoionization,
particularly for gas in the halo. We find that in many regions at high latitude
this source is adequate to account for the observed ionization so there is no
need to find ways to transport stellar photons from the disk. The flux from
cooling SNRs sets a floor on the ionization along any line of sight. Our model
flux is also shown to be consistent with the diffuse soft X-ray background and
with soft X-ray observations of external galaxies.
We consider the ionization of the clouds observed towards the halo star HD
93521, for which there are no O stars close to the line of sight. We show that
the observed ionization can be explained successfully by our model EUV/soft
X-ray flux from cooling hot gas. In particular, we can match the H alpha
intensity, the S++/S+ ratio, and the C+* column. From observations of the
ratios of columns of C+* and either S+ or H0, we are able to estimate the
thermal pressure in the clouds. The slow clouds require high (~10^4 cm^-3 K)
thermal pressures to match the N(C+*)/N(S+) ratio. Additional heating sources
are required for the slow clouds to maintain their ~7000 K temperatures at
these pressures, as found by Reynolds, Hausen & Tufte (1999).Comment: AASTeX 5.01; 34 pages, 2 figures; submitted to Astrophysical Journa
An Independent Audit of Pharma Influence in Public Mental Health Trusts in England
Without data, many people still think pharmaceutical companies’ influence is negligible, even benevolent. We audited their marketing activities, alongside simple financials. 43/53 Trusts responded to Freedom-of-Information-Act requests. Trusts’ policies varied in prohibiting seven activities: 86% (gifts) to 37% (leaflets). In practice, industry-sponsored training events (51%)/ direct talks (40%) were common (averaging 36 sponsored events/talks per Trust that year). Only 8/36 (22.2%) Trusts provided legally-required Conflicts-of-Interests registers; 5 (14%) had none.
The top training-provider/sponsor received almost double where they trained most, and the largest share (average 33.6%) of the whole psychiatric-medications budget everywhere. Two most expensive medications (branded, “Long-Acting-Injectables”) were prescribed very differently (0%-77%). Independent post-qualification medical education/ marketing-bans are needed to avoid extremely over-medicalised practice. 5 Trusts already ban Pharma marketing
Entanglement creation and distribution on a graph of exchange-coupled qutrits
We propose a protocol that allows both the creation and distribution of
entanglement, resulting in two distant parties (Alice and Bob) conclusively
sharing a bipartite Bell State. The system considered is a graph of three-level
objects ("qutrits") coupled by SU(3) exchange operators. The protocol begins
with a third party (Charlie) encoding two lattice sites in unentangled states,
and allowing unitary evolution under time. Alice and Bob perform a projective
measurement on their respective qutrits at a given time, and obtain a
maximally-entangled Bell state with a certain probablility. We also consider
two further protocols, one based on simple repetition and the other based on
successive measurements and conditional resetting, and show that the cumulative
probability of creating a Bell state between Alice and Bob tends to unity.Comment: Added seven references, clarified argument for eqn (16
The Absorption Signatures of Dwarf Galaxies: The z=1.04 Multicloud Weak MgII Absorber toward PG 1634+706
We analyze high resolution spectra of a multi--cloud weak [defined as
W_r(MgII) < 0.3 A] absorbing system along the line of sight to PG 1634+706.
This system gives rise to a partial Lyman limit break and absorption in MgII,
SiII, CII, SiIII, SiIV, CIV, and OVI. The lower ionization transitions arise in
two kinematic subsystems with a separation of ~150 km/s. Each subsystem is
resolved into several narrow components, having Doppler widths of 3-10 kms. For
both subsystems, the OVI absorption arises in a separate higher ionization
phase, in regions dominated by bulk motions in the range of 30-40 km/s. The two
OVI absorption profiles are kinematically offset by ~50 km/s with respect to
each of the two lower ionization subsystem. In the stronger subsystem, the
SiIII absorption is strong with a distinctive, smooth profile shape and may
partially arise in shock heated gas. Moreover, the kinematic substructure of
SiIV traces that of the lower ionization MgII, but may be offset by ~3 km/s.
Based upon photoionization models, constrained by the partial Lyman limit
break, we infer a low metallicity of ~0.03 solar for the low ionization gas in
both subsystems. The broader OVI phases have a somewhat higher metallicity, and
they are consistent with photoionization; the profiles are not broad enough to
imply production of OVI through collisional ionization. Various models,
including outer disks, dwarf galaxies, and superwinds, are discussed to account
for the phase structure, metallicity, and kinematics of this absorption system.
We favor an interpretation in which the two subsystems are produced by
condensed clouds far out in the opposite extremes of a multi-layer dwarf galaxy
superwind
Modelling the impact of social mixing and behaviour on infectious disease transmission: application to SARS-CoV-2
In regard to infectious diseases socioeconomic determinants are strongly
associated with differential exposure and susceptibility however they are
seldom accounted for by standard compartmental infectious disease models. These
associations are explored here with a novel compartmental infectious disease
model which, stratified by deprivation and age, accounts for population-level
behaviour including social mixing patterns. As an exemplar using a fully
Bayesian approach our model is fitted, in real-time if required, to the UKHSA
COVID-19 community testing case data from England. Metrics including
reproduction number and forecasts of daily case incidence are estimated from
the posterior samples. From this UKHSA dataset it is observed that during the
initial period of the pandemic the most deprived groups reported the most cases
however this trend reversed after the summer of 2021. Forward simulation
experiments based on the fitted model demonstrate that this reversal can be
accounted for by differential changes in population level behaviours including
social mixing and testing behaviour, but it is not explained by the depletion
of susceptible individuals. In future epidemics, with a focus on socioeconomic
factors the approach outlined here provides the possibility of identifying
those groups most at risk with a view to helping policy-makers better target
their support.Comment: Main article: 25 pages, 6 figures. Appendix 2 pages, 1 figure.
Supplementary Material: 15 pages, 14 figures. Version 2 - minor updates:
fixed typos, updated mathematical notation and small quantity of descriptive
text added. Version 3 - minor update: made colour coding consistent across
all time series figure
Polyadenylation regulates the stability of Trypanosoma brucei mitochondrial RNAs
Polyadenylation of RNAs plays a critical role in modulating rates of RNA turnover and ultimately in controlling gene expression in all systems examined to date. In mitochondria, the precise mechanisms by which RNAs are degraded, including the role of polyadenylation, are not well understood. Our previous in organello pulse-chase experiments suggest that poly(A) tails stimulate degradation of mRNAs in the mitochondria of the protozoan parasite Trypanosoma brucei (Militello, K. T., and Read, L. K. (2000) Mol. Cell. Biol. 21, 731-742). In this report, we developed an in vitro assay to directly examine the effects of specific 3′-sequences on RNA degradation. We found that a salt-extracted mitochondrial membrane fraction preferentially degraded polyadenylated mitochondrially and non-mitochondrially encoded RNAs over their non-adenylated counterparts. A poly(A) tail as short as 5 nucleotides was sufficient to stimulate rapid degradation, although an in vivo tail length of 20 adenosines supported the most rapid decay. A poly(U) extension did not promote rapid RNA degradation, and RNA turnover was slowed by the addition of uridine residues to the poly(A) tail. To stimulate degradation, the poly(A) element must be located at the 3′ terminus of the RNA. Finally, we demonstrate that degradation of polyadenylated RNAs occurs in the 3′ to 5′ direction through the action of a hydrolytic exonuclease. These experiments demonstrate that the poly(A) tail can act as a cis-acting element to facilitate degradation of T. brucei mitochondrial mRNAs
Discussion: Salmon on Explanatory Relevance
One of the motivations for Salmon's (1984) causal theory of explanation was
the explanatory irrelevance exhibited by many arguments conforming to Hempel's
covering-law models of explanation. However, the nexus of causal processes
and interactions characterized by Salmon is not rich enough to supply the necessary
conception of explanatory relevance. Salmon's (1994) revised theory,
which is briefly criticized on independent grounds, fares no better. There is some
possibility that the two-tiered structure of explanation described by Salmon (1984)
may be pressed into service, but more work would have to be done. Ironically,
Salmon's difficulties are similar to those suffered by his seventeenth-century
predecessors
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