1,060 research outputs found
Quantum Monte Carlo Calculations of Pion Scattering from Li
We show that the neutron and proton transition densities predicted by recent
quantum Monte Carlo calculations for A=6,7 nuclei are consistent with pion
scattering from 6Li and 7Li at energies near the Delta resonance. This has
provided a microscopic understanding of the enhancement factors for quadrople
excitations, which were needed to describe pion inelastic scattering within the
nuclear shell model of Cohen and Kurath.Comment: 10 pages, REVTeX, 3 postscript figures; added calculation of elastic
and inelastic pion scattering from 6Li at multiple energie
Making history: intentional capture of future memories
Lifelogging' technology makes it possible to amass digital data about every aspect of our everyday lives. Instead of focusing on such technical possibilities, here we investigate the way people compose long-term mnemonic representations of their lives. We asked 10 families to create a time capsule, a collection of objects used to trigger remembering in the distant future. Our results show that contrary to the lifelogging view, people are less interested in exhaustively digitally recording their past than in reconstructing it from carefully selected cues that are often physical objects. Time capsules were highly expressive and personal, many objects were made explicitly for inclusion, however with little object annotation. We use these findings to propose principles for designing technology that supports the active reconstruction of our future past
Cross-Newell equations for hexagons and triangles
The Cross-Newell equations for hexagons and triangles are derived for general
real gradient systems, and are found to be in flux-divergence form. Specific
examples of complex governing equations that give rise to hexagons and
triangles and which have Lyapunov functionals are also considered, and explicit
forms of the Cross-Newell equations are found in these cases. The general
nongradient case is also discussed; in contrast with the gradient case, the
equations are not flux-divergent. In all cases, the phase stability boundaries
and modes of instability for general distorted hexagons and triangles can be
recovered from the Cross-Newell equations.Comment: 24 pages, 1 figur
Exactly soluble model for self-gravitating D-particles with the wormhole
We consider D-particles coupled to the CGHS dilaton gravity and obtain the
exact wormhole geometry and trajectories of D-particles by introducing the
exotic matter. The initial static wormhole background is not stable after
infalling D-particles due to the classical backreaction of the geometry so that
the additional exotic matter source should be introduced for the stability.
Then, the traversable wormhole geometry naturally appears and the D-particles
can travel through it safely. Finally, we discuss the dynamical evolution of
the wormhole throat and the massless limit of D-particles.Comment: 16 pages, 3 figures, revte
Prospective evaluation of quality of life after conventional abdominal aortic aneurysm surgery
Objectives:To evaluate the changes in quality of life following conventional abdominal aortic aneurysm repair.Design:Prospective study.Materials and methods:Fifty-nine consecutive patients (50 men; nine women) in two surgical centres were investigated preoperatively, and at 6 weeks, 3 months and 6 months postoperatively. Quality of life was measured using the Short Form 36 (SF 36) questionnaire and the York Quality of Life questionnaire, from which the Rosser index was calculated.Results:Rosser index assessment showed restoration of quality of life to preoperative levels by 3 months, and significant improvement at 6 months. Changes in the SF 36 revealed significant improvement in mental health, and physical role limitation at all times postoperatively. Social function worsened at 6 weeks but improved to preoperative levels by 3 and 6 months after surgery.Conclusions:Quality of life was improved after open aortic aneurysm repair. The time course of recovery shows a predominant improvement between 6 weeks and 3 months postoperatively
The position of graptolites within Lower Palaeozoic planktic ecosystems.
An integrated approach has been used to assess the palaeoecology of graptolites both as a discrete group and also as a part of the biota present within Ordovician and Silurian planktic realms. Study of the functional morphology of graptolites and comparisons with recent ecological analogues demonstrates that graptolites most probably filled a variety of niches as primary consumers, with modes of life related to the colony morphotype. Graptolite coloniality was extremely ordered, lacking any close morphological analogues in Recent faunas. To obtain maximum functional efficiency, graptolites would have needed varying degrees of coordinated automobility. A change in lifestyle related to ontogenetic changes was prevalent within many graptolite groups. Differing lifestyle was reflected by differing reproductive strategies, with synrhabdosomes most likely being a method for rapid asexual reproduction. Direct evidence in the form of graptolithophage 'coprolitic' bodies, as well as indirect evidence in the form of probable defensive adaptations, indicate that graptolites comprised a food item for a variety of predators. Graptolites were also hosts to a variety of parasitic organisms and provided an important nutrient source for scavenging organisms
Gyroid cuticular structures in butterfly wing scales: biological photonic crystals
We present a systematic study of the cuticular structure in the butterfly wing scales of some papilionids (Parides sesostris and Teinopalpus imperialis) and lycaenids (Callophrys rubi, Cyanophrys remus, Mitoura gryneus and Callophrys dumetorum). Using published scanning and transmission electron microscopy (TEM) images, analytical modelling and computer-generated TEM micrographs, we find that the three-dimensional cuticular structures can be modelled by gyroid structures with various filling fractions and lattice parameters. We give a brief discussion of the formation of cubic gyroid membranes from the smooth endoplasmic reticulum in the scale's cell, which dry and harden to leave the cuticular structure behind when the cell dies. The scales of C. rubi are a potentially attractive biotemplate for producing three-dimensional optical photonic crystals since for these scales the cuticle-filling fraction is nearly optimal for obtaining the largest photonic band gap in a gyroid structure
Microlensing by natural wormholes: theory and simulations
We provide an in depth study of the theoretical peculiarities that arise in
effective negative mass lensing, both for the case of a point mass lens and
source, and for extended source situations. We describe novel observational
signatures arising in the case of a source lensed by a negative mass. We show
that a negative mass lens produces total or partial eclipse of the source in
the umbra region and also show that the usual Shapiro time delay is replaced
with an equivalent time gain. We describe these features both theoretically, as
well as through numerical simulations. We provide negative mass microlensing
simulations for various intensity profiles and discuss the differences between
them. The light curves for microlensing events are presented and contrasted
with those due to lensing produced by normal matter. Presence or absence of
these features in the observed microlensing events can shed light on the
existence of natural wormholes in the Universe.Comment: 16 pages, 24 postscript figures (3 coloured), revtex style, submitted
to Phys. Rev.
Optimizing anticancer therapy in metastatic non-castrate prostate cancer: American society of clinical oncology clinical practice guideline
Purpose This clinical practice guideline addresses abiraterone or docetaxel with androgen-deprivation therapy (ADT) for metastatic prostate cancer that has not been treated (or has been minimally treated) with testosterone-lowering agents. Methods Standard therapy for newly diagnosed metastatic prostate cancer has been ADT alone. Three studies have compared ADT alone with ADT and docetaxel, and two studies have compared ADT alone with ADT and abiraterone. Results Three prospective randomized studies (GETUG-AFU 15, STAMPEDE, and CHAARTED) examined overall survival (OS) with adding docetaxel to ADT. STAMPEDE and CHAARTED favored docetaxel (hazard ratio [HR], 0.78; 95% CI, 0.66 to 0.93; n = 2,962 and HR, 0.73; 95% CI, 0.59 to 0.89; n = 790, respectively). GETUG-AFU 15 was negative. LATITUDE and STAMPEDE examined the impact on OS of adding abiraterone (with prednisone or prednisolone) to ADT. LATITUDE and STAMPEDE favored abiraterone (HR, 0.62; 95% CI, 0.51 to 0.76; n = 1,199 and HR, 0.63; 95% CI, 0.52 to 0.76; n = 1,917, respectively). Recommendations ADT plus docetaxel or abiraterone in newly diagnosed metastatic non-castrate prostate cancer offers a survival benefit as compared with ADT alone. The strongest evidence of benefit with docetaxel is in men with de novo high-volume (CHAARTED criteria) metastatic disease. Similar survival benefits are seen using abiraterone acetate in high-risk patients (LATITUDE criteria) and in the metastatic population in STAMPEDE. ADT plus abiraterone and ADT plus docetaxel have not been compared, and it is not known if some men benefit more from one regimen as opposed to the other. Fitness for chemotherapy, patient comorbidities, toxicity profiles, quality of life, drug availability, and cost should be considered in this decision. Additional information is available at www.asco.org/genitourinary-cancer-guidelines
Rotating Black Branes in the presence of nonlinear electromagnetic field
In this paper, we consider a class of gravity whose action represents itself
as a sum of the usual Einstein-Hilbert action with cosmological constant and an
gauge field for which the action is given by a power of the Maxwell
invariant. We present a class of the rotating black branes with Ricci flat
horizon and show that the presented solutions may be interpreted as black brane
solutions with two event horizons, extreme black hole and naked singularity
provided the parameters of the solutions are chosen suitably. We investigate
the properties of the solutions and find that for the special values of the
nonlinear parameter, the solutions are not asymptotically anti-deSitter. At
last, we obtain the conserved quantities of the rotating black branes and find
that the nonlinear source effects on the electric field, the behavior of
spacetime, type of singularity and other quantities.Comment: 7 pages, 5 figures, to appear in EPJ
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