2,054 research outputs found
Taut and delicate balance: reflections in the eye of Thomas Brown
Common sense, affirmed Ferrier, can neither be set
aside nor taken for granted by philosophy. Rather, it
must be converted into philosophy, and this "by accepting
completely and faithfully the facts and expressions of
common sense as given in their primitive obscurity, and
then by construing them without violence, without addition,
and without diminution into clearer and more intelligible
forms". In the period under discussion, the early nineteenth century, the attempt to elucidate the phenomena of
mind and their linguistic moulds came under the title of
'mental science' or 'analysis'. More specifically, the
process envisaged for this science was inductive, what
Dugald Stewart would call a dual operation of analysis
and synthesis or Cabanis the method of decomposition and
recomposition. Agreement on the use of such a procedure
for the philosophy of mind or on the details of the technique employed was never unanimous: in the case of the
latter, it had first to be established whether the
'scientist' was dealing at the outset with 'simple' or
'compound' phenomena and whether he was to proceed from
the known to the unknown or vice versa. Beneath this
controversy lay the roots of an earlier separation between
the 'analysis of nature' (wherein our representations
are viewed as scattered across the linear board of their
presentation, and so distantly and only vaguely related)
and the 'analytic of imagination' (which arranges and
orders the disparate segments of temporal presentation
into a simultaneous table of comparative representations).
Michel Foucault, whose distinction this is, argues that
these two directions of analysis begin to converge towards the end of the eighteenth century. But the moment
of convergence, being fraught with difficulties for those
at the intersection, is less than happy. This uneasiness
of mind accounts, moreover, for the strain of conversion
in 'Common Sense' philosophy.
Nevertheless, where the struggles at the juncture
are most intense, there is a commensurate heightening of
philosophical awareness. Faintly visible in the first
inquiries of Thomas Brown (1778-1820) into causality and
volition, it reaches a crescendo in his more mature reflections on memory and attention, the nature of consciousness and reflection itself. Emerging with this
apprehension, and giving it depth, is Brown's sensitivity
to the feelings of selfhood and his belief in the recovery,
however imaginary, of the individual's past. That sense
of an order to be captured and restored, combined with a
recognition of the affections which, more often, reap
the havoc of human nature, create in his writings the
sort of excitement associated not with the resolution of
dilemmas, but with a prolonged, agonizing and continual
tension. The subsequent discussion moves towards as it
is moved by that realization
Pretreatment with beta-blockers and the frequency of hypokalemia in patients with acute chest pain
Plasma potassium concentration was measured at admission in 1234 patients who presented with acute chest pain. One hundred and ninety five patients were on P blockers before admission. The potassium concentrations of patients admitted early (within four hours of onsetof symptoms) were compared with those admitted later (4-18 hours after onset of symptoms). There was a transient fall in plasma potassium concentrations in patients not pre-treated with , B blockers. This was not seen in patients who had been on P blockers before admission. Nonselective, B blockers were more effective than cardioselective agents in maintaining concentrationsof plasma potassium. These findings suggest a mechanism for the beneficial effects of ,B blockers on morbidity and mortality in acute myocardial infarction
A high efficiency, low background detector for measuring pair-decay branches in nuclear decay
We describe a high efficiency detector for measuring electron-positron pair
transitions in nuclei. The device was built to be insensitive to gamma rays and
to accommodate high overall event rates. The design was optimized for total
pair kinetic energies up to about 7 MeV.Comment: Accepted for publication by Nucl. Inst. & Meth. in Phys. Res. A (NIM
A
The ovarian cancer oncobiome.
Humans and other mammals are colonized by microbial agents across the kingdom which can represent a unique microbiome pattern. Dysbiosis of the microbiome has been associated with pathology including cancer. We have identified a microbiome signature unique to ovarian cancers, one of the most lethal malignancies of the female reproductive system, primarily because of its asymptomatic nature during the early stages in development. We screened ovarian cancer samples along with matched, and non-matched control samples using our pan-pathogen array (PathoChip), combined with capture-next generation sequencing. The results show a distinct group of viral, bacterial, fungal and parasitic signatures of high significance in ovarian cases. Further analysis shows specific viral integration sites within the host genome of tumor samples, which may contribute to the carcinogenic process. The ovarian cancer microbiome signature provides insights for the development of targeted therapeutics against ovarian cancers
Linear Stability of Triangular Equilibrium Points in the Generalized Photogravitational Restricted Three Body Problem with Poynting-Robertson Drag
In this paper we have examined the linear stability of triangular equilibrium
points in the generalised photogravitational restricted three body problem with
Poynting-Robertson drag. We have found the position of triangular equilibrium
points of our problem. The problem is generalised in the sense that smaller
primary is supposed to be an oblate spheroid. The bigger primary is considered
as radiating. The equations of motion are affected by radiation pressure force,
oblateness and P-R drag. All classical results involving photogravitational and
oblateness in restricted three body problem may be verified from this result.
With the help of characteristic equation, we discussed the stability. Finally
we conclude that triangular equilibrium points are unstable.Comment: accepted for publication in Journal of Dynamical Systems & Geometric
Theories Vol. 4, Number 1 (2006
Demonstration of the anthelmintic potency of marimastat in the Heligmosomoides polygyrus rodent model
In the course of a structure based drug discovery program the known anticancer candidate marimastat was uncovered as a potent inhibitor of an enzyme in nematode cuticle biogenesis. It was shown to kill Caenorhabditis elegans, and the sheep parasites Haemonchus contortus and Teladorsagia circumcinta via an entirely novel nematode-specific pathway, specifically by inhibiting cuticle-remodelling enzymes that the parasites require for the developmentally essential moulting process. This discovery prompted an investigation of the compound's effect on Heligmosomoides polygyrus parasites in a mouse model of helminth infection. Mice were administered the drug via oral gavage daily from day of infection for a period of 2 wk. A second group received the drug via intra-peritoneal implantation of an osmotic minipump for 4 wk. Control groups were administered identical volumes of water by oral gavage in both cases. Counts of H. polygyrus faecal egg and larval load showed that marimastat effected a consistent and significant reduction in egg laying, and a consistent but minor reduction in adult worm load when administered every day, starting on the first day of infection. However, the drug failed to have any significant effect on egg counts or worm burdens when administered to mice with established infections. Therefore, marimastat does not appear to show promise as an anthelmintic in gastrointestinal nematode infections, although other metalloproteases such as batimastat may prove more effective
Theoretical analysis of the focusing of acoustic waves by two-dimensional sonic crystals
Motivated by a recent experiment on acoustic lenses, we perform numerical
calculations based on a multiple scattering technique to investigate the
focusing of acoustic waves with sonic crystals formed by rigid cylinders in
air. The focusing effects for crystals of various shapes are examined. The
dependance of the focusing length on the filling factor is also studied. It is
observed that both the shape and filling factor play a crucial role in
controlling the focusing. Furthermore, the robustness of the focusing against
disorders is studied. The results show that the sensitivity of the focusing
behavior depends on the strength of positional disorders. The theoretical
results compare favorably with the experimental observations, reported by
Cervera, et al. (Phys. Rev. Lett. 88, 023902 (2002)).Comment: 8 figure
The calibration of the Sudbury Neutrino Observatory using uniformly distributed radioactive sources
The production and analysis of distributed sources of 24Na and 222Rn in the
Sudbury Neutrino Observatory (SNO) are described. These unique sources provided
accurate calibrations of the response to neutrons, produced through
photodisintegration of the deuterons in the heavy water target, and to low
energy betas and gammas. The application of these sources in determining the
neutron detection efficiency and response of the 3He proportional counter
array, and the characteristics of background Cherenkov light from trace amounts
of natural radioactivity is described.Comment: 24 pages, 13 figure
On the verge of Umdeutung in Minnesota: Van Vleck and the correspondence principle (Part One)
In October 1924, the Physical Review, a relatively minor journal at the time,
published a remarkable two-part paper by John H. Van Vleck, working in virtual
isolation at the University of Minnesota. Van Vleck combined advanced
techniques of classical mechanics with Bohr's correspondence principle and
Einstein's quantum theory of radiation to find quantum analogues of classical
expressions for the emission, absorption, and dispersion of radiation. For
modern readers Van Vleck's paper is much easier to follow than the famous paper
by Kramers and Heisenberg on dispersion theory, which covers similar terrain
and is widely credited to have led directly to Heisenberg's "Umdeutung" paper.
This makes Van Vleck's paper extremely valuable for the reconstruction of the
genesis of matrix mechanics. It also makes it tempting to ask why Van Vleck did
not take the next step and develop matrix mechanics himself.Comment: 82 page
WMAP constraints on scalar-tensor cosmology and the variation of the gravitational constant
We present observational constraints on a scalar-tensor gravity theory by
test for CMB anisotropy spectrum. We compare the WMAP temperature
power spectrum with the harmonic attractor model, in which the scalar field has
its harmonic effective potential with curvature in the Einstein
conformal frame and the theory relaxes toward Einstein gravity with time. We
found that the present value of the scalar coupling, i.e. the present level of
deviation from Einstein gravity , is bounded to be smaller than
(), and () for . This constraint is much stronger than the bound from the solar
system experiments for large models, i.e., and 0.3 in
and limits, respectively. Furthermore, within the framework
of this model, the variation of the gravitational constant at the recombination
epoch is constrained as , and
.Comment: 7 page
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