7,443 research outputs found
Clues for consequentialists
In an influential paper, James Lenman argues that consequentialism can provide no basis for ethical guidance, because we are irredeemably ignorant of most of the consequences of our actions. If our ignorance of distant consequences is great, he says, we can have little reason to recommend one action over another on consequentialist grounds. In this article, I show that for reasons to do with statistical theory, the cluelessness objection is too pessimistic. We have good reason to believe that certain patterns of action will tend to have better consequences, and we have good reason to recommend acting in accordance with strategies based on those advantageous patterns. I close by saying something about the strategies that this argument should lead us to favour.</jats:p
Spectropolarimetry of the borderline Seyfert 1 galaxy ESO 323-G077
We report the detection of high linear polarization in the bright Seyfert 1
galaxy ESO 323-G077. Based on optical spectropolarimetry with FORS1 at the VLT
we find a continuum polarization which ranges from 2.2 % at 8300A to 7.5 % at
3600A. Similar amounts of linear polarization are found for the broad emission
lines, while the narrow lines are not polarized. The position angle of the
polarization is independent of the wavelength and found to be perpendicular to
the orientation of the extended [OIII] emission cone of this galaxy. Within the
standard model of Seyfert nuclei the observations can be well understood
assuming that this AGN is observed at an inclination angle where the nucleus is
partially obscured and seen mainly indirectly in the light scattered by dust
clouds within or above the torus and the illuminated inner edge of the dust
torus itself. Hence we conclude that ESO 323-G077 is a borderline Seyfert 1
galaxy which can provide important information on the geometric properties of
active nuclei
Religion and scientism: a shared cognitive conundrum
This article challenges the claim that the rise of naturalism is devastating to religious belief. This claim hinges on an extreme interpretation of naturalism called scientism, the metaphysical view that science offers an exhaustive account of the real. For those committed to scientism, religious discourse is epistemically illegitimate, because it refers to matters that transcend?and so cannot be verified by?scientific inquiry. This article reconstructs arguments from the phenomenological tradition that seem to undercut this critique, viz., arguments that scientism itself cannot be justified without recourse to matters that transcend scientific inquiry. If this is true, then scientism and religion share a cognitive conundrum: a commitment to truths that cannot in principle be known from our current perspective
Energies of B_s meson excited states - a lattice study
This is a follow-up to our earlier work on the energies and radial
distributions of heavy-light mesons. The heavy quark is taken to be static
(infinitely heavy) and the light quark has a mass about that of the strange
quark. We now concentrate on the energies of the excited states with higher
angular momentum and with a radial node. A new improvement is the use of
hypercubic blocking in the time direction.
The calculation is carried out with dynamical fermions on a 16 cubed times 32
lattice with a lattice spacing approximately 0.1 fm generated using a
non-perturbatively improved clover action.
In nature the closest equivalent of this heavy-light system is the B_s meson,
which allows us to compare our lattice calculations to experimental results
(where available) or to give a prediction where the excited states,
particularly P-wave states, should lie. We pay special attention to the
spin-orbit splitting, to see which one of the states (for a given angular
momentum L) has the lower energy. An attempt is made to understand these
results in terms of the Dirac equation.Comment: 35 pages. v3: Data from two new lattices added. New results in
several chapter
Studies on the Interactions between Arachidonic Acid Metabolism and Calcium in Regulating Vasopressin-Induced Water Permeability in the Toad Urinary Bladder
The toad urinary bladder and epithelial cells isolated from it were found to synthesize prostaglandin E (PGE) and thromboxane A2 (TXA2). The syntheses of both of these compounds were found to be stimulated by arginine-vasopressin and by its non-pressor antidiuretic analog I-deamino-8-D-arginine-vasopressin. cAMP, a putative second messenger for vasopressin in the toad bladder, when added to the incubation media, did not affect TXA2 synthesis. However, in the isolated cells both TXA2 and PGE syntheses were found to be stimulated by calcium. In studies using the isolated toad bladder, inhibition of TXA2 synthesis with imidazole (1 mM) and 7-(1-imidazolyl)-heptanoic acid (50-100 µM) was found to inhibit vasopressin-stimulated water flow to a maximum of 30%. Similarly, an antagonist of TXA2 action, trans-13-azaprostanoic acid (50-300 µM) inhibited vasopressin-stimulated water flow in a dose-dependent fashion to a maximum of 35%, while the biologically inactive cis isomer was without effect. Several compounds which exhibit TXA2-like effects in other systems, (15Z)-hydroxy-9α,11α-(epoxymethano)prosta-5Z,13E dienoic acid (U44069), its 9α,11α-(methanoepoxy) isomer (U46619), and TXB2 , mimicked the hydroosmotic effect of vasopressin. This action was inhibited in a dose-dependent fashion by trans-13-azaprostanoic acid while cis-13-azaprostanoic acid was without effect. Vasopressin was found to elicit an enhancement in 45Ca efflux from prelabelled toad bladder epithelial cells. Compartmental analysis of 45Ca efflux from prelabelled cells revealed three components. Studies using EGTA, lanthanum, and mitochondrial inhibitors suggested that the first component of efflux (S1) represented 45Ca bound to heterogeneous sites on the extracellular surface of the plasma membrane, the second component (S2) represented 45Ca bound to some intracellular site(s), and the third component (S3) was composed of two sites, a slowly exchanging site near the plasma membrane, and mitochondria. Vasopressin reduced the sizes of calcium pools S1 and S3. Exogenous cAMP also reduced the size of S3, but increased the size of S2. The TXA2 mimetic, U46619, acted similarly to cAMP; it decreased the size of pool S3 and increased the size of pool S2. The TXA2 synthesis inhibitor 7-(1-imidazolyl)-heptanoic acid blocked the effect of vasopressin to reduce the size of S3. The TXA2 antagonist trans-13- azaprostanoic acid, in concentrations not lethal to the isolated cells, inhibited vasopressin-stimulated water flow only slightly (17%) and did not significantly alter vasopressin\u27s effects on 45Ca kinetics. However, trans-13-azaprostanoic acid significantly blocked the effect of U46619 to decrease the size of S3. Exogenous PGE 1, 1 µM, a concentration which completely inhibits vasopressin-stimulated water flow, enhanced both the efflux and influx of 45Ca. However, net cellular 45Ca was increased. The increased 45Ca was located entirely in pool S3. These results are consistent with a hypothesis wherein vasopressin causes a net release of calcium from an intracellular storage site, perhaps mitochondria. PGE and TXA2 syntheses are stimulated, perhaps by the altered calcium fluxes. TXA2, like vasopressin, reduces the size of a putative mitochondrial calcium compartment, and inhibition of TXA2 synthesis, or antagonism of TXA2 action, inhibits vasopressin-stimulated water flow. PGE enhances 45Ca uptake into the epithelial cells and increases the size of pool S3, resulting in inhibition of vasopressin-stimulated water flow
Rural School Nursing in Colorado: New Perspectives
Rural school nurses face the challenge of practicing nursing care in an environment that is not built around health care. They are often the only person with health care knowledge in the school, and therefore feel alone. There has been little research into the perceptions of school nurses related to their experiences. To begin to fill this gap, a descriptive phenomenology dived deeply into the lived experiences of nine rural school nurses. The nurse researcher conducted face – to – face interviews with these nurses. One main question related to their experiences and five sub-questions yielded a wide variety of responses and concerns which were then analyzed by constant comparative analysis and coded into themes and subthemes. The revealed themes included: Children’s Multiple Health Issues, Communication Challenges, and Unmet Students’ Needs. The results revealed that these rural school nurses work with children who live in extreme poverty and homeless conditions, with very few resources available. The children in these schools have a plethora of acute, chronic, and rare health conditions and face many mental health challenges. These rural school nurses also revealed challenges in communicating with children, parents, and other health professionals, and that there are many unmet student needs because of missing resources and lack of time
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A novel role for the TIR domain in association with pathogen-derived elicitors
Plant innate immunity is mediated by Resistance (R) proteins, which bear a striking resemblance to animal molecules of similar function. Tobacco N is a TIR-NB-LRR R gene that confers resistance to Tobacco mosaic virus, specifically the p50 helicase domain. An intriguing question is how plant R proteins recognize the presence of pathogen-derived Avirulence (Avr) elicitor proteins. We have used biochemical cell fraction and immunoprecipitation in addition to confocal fluorescence microscopy of living tissue to examine the association between N and p50. Surprisingly, both N and p50 are cytoplasmic and nuclear proteins, and N's nuclear localization is required for its function. We also demonstrate an in planta association between N and p50. Further, we show that N's TIR domain is critical for this association, and indeed, it alone can associate with p50. Our results differ from current models for plant innate immunity that propose detection is mediated solely through the LRR domains of these molecules. The data we present support an intricate process of pathogen elicitor recognition by R proteins involving multiple subcellular compartments and the formation of multiple protein complexes. © 2007 Burch-Smith et al
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