The information content of a new observable: the case of the nuclear neutron skin

We address two questions pertaining to the uniqueness and usefulness of a new observable: (i) Considering the current theoretical knowledge, what novel information does new measurement bring in? (ii) How can new data reduce uncertainties of current theoretical models? We illustrate these points by studying the radius of the neutron distribution of a heavy nucleus, a quantity related to the equation of state for neutron matter that determines properties of nuclei and neutron stars. By systematically varying parameters of two theoretical models and studying the resulting confidence ellipsoid, we quantify the relationships between the neutron skin and various properties of finite nuclei and infinite nuclear matter. Using the covariance analysis, we identify observables and pseudo-observables that correlate, and do not correlate, with the neutron skin. By adding the information on the neutron radius to the pool of observables determining the energy functional, we show how precise experimental determination of the neutron radius in $^{208}$Pb would reduce theoretical uncertainties on the neutron matter equation of state.Comment: 5 pages, 3 figure

Reflexiones acerca de la prudencia en Kant

Kant discusses prudence in many different contexts. His pragmatic anthropology is a doctrine of prudence; Kant lectured on anthropology from 1772-1773 until 1795-1796 and published a resumee of those lectures in 1798. In his moral philosophy, prudence appear under various aspects. First, it is an opponent to pure morality, trying to guide human life instead of conceding primacy to the categorical imperative; but on the other hand it is a moral duty to cultivate prudence as an human faculty which enables us to master pragmatic challenges in our life. And, thirdly, moral philosophy shows the possibility of a convergence of morality and prudence; you can find this in Kant's conception of the highest good in ethics and in political philosophy, in the idea, that moral actions will show themselves to be the most prudent. Another important aspect of Kant's philosophy of prudence is the problem of freedom; in the Critique of Practical Reason the moral law is the necessary and sufficient condition of freedom; but then raises the question about whether prudent actions can be free or are merely the products of the determination of the inner sense.Kant analiza el tema de la prudencia en contextos muy diferentes. Su antropología pragmática es una doctrina de la prudencia; un resumen de las lecciones sobre antropología impartidas desde 1772-1773 hasta 1795-1796 fueron publicadas en 1798. En su filosofía moral la prudencia aparece bajo aspectos muy diversos. En primer lugar es un oponente de la pura moralidad que trata de guiar la vida humana concediendo prioridad al imperativo categórico; sin embargo, por otro lado, supone un deber moral el cultivar la prudencia como una facultad humana capaz de introducir cambios pragmáticos en nuestra vida. Y, en tercer lugar, la filosofía moral muestra la posibilidad de una convergencia entre moralidad y prudencia; cabe encontrar esto en la concepción kantiana del sumo bien en la ética y en la filosofía política, en la idea de que las acciones morales se mostrarán al volverse más prudentes. Otro aspecto relevante de la reflexión kantiana sobre la prudencia es el problema de la libertad; en la Crítica de la razón práctica, la ley moral es la condición necesaria y suficiente de la libertad; pero entonces se plantea la cuestión de si las acciones prudentes pueden ser libres O son meros productos de la determinación del sentido interno

La bellezza nel segno del rifiuto

Beauty and its refusal are not merely a cipher of contemporaneity but a topic discussed since antiquity. The rivalry between lyre and flute, between harmony, mathematically determinable, and melody, gatherable only by hearing, arises from the myth, from the fight between Apollo and Marsia, where Greece and Phrygia, Europe and Asia are opposed in a civilisations collision. In modernity this collision arose again as political, whereas the egalitarian melody is opposed to the elitist harmony. Into this collision we find fine arts, not beauty anymore: fine arts leave the territory of beaux arts of fine poetry but remain, for contemporaneity, works of art. But what do arts, not beauty anymore, or even ugly, want? Which aim do they pursue? How can we judge them

Electric dipole polarizability and the neutron skin

The recent high-resolution measurement of the electric dipole (E1) polarizability (alphad) in 208Pb [Phys. Rev. Lett. 107, 062502 (2011)] provides a unique constraint on the neutron-skin thickness of this nucleus. The neutron-skin thickness (rskin) of 208Pb is a quantity of critical importance for our understanding of a variety of nuclear and astrophysical phenomena. To assess the model dependence of the correlation between alphad and rskin, we carry out systematic calculations for 208Pb, 132Sn, and 48Ca based on the nuclear density functional theory (DFT) using both non-relativistic and relativistic energy density functionals (EDFs). Our analysis indicates that whereas individual models exhibit a linear dependence between alphad and rskin, this correlation is not universal when one combines predictions from a host of different models. By averaging over these model predictions, we provide estimates with associated systematic errors for rskin and alphad for the nuclei under consideration. We conclude that precise measurements of rskin in both 48Ca and 208Pb---combined with the recent measurement of alphad---should significantly constrain the isovector sector of the nuclear energy density functional.Comment: Manuscript contains 5 pages, 2 figures, and 1 table. Submitted to Physical Review Letter

Lifestyle of Shellmound Builders in Brazil (galley proofs)

The contact of inland and coastal prehistoric groups in Brazil is believed to have been restricted to regions with no geographical barrier, as is the case in the Ribeira de Iguape valley. The inland osteological collection from the riverine shellmound Moraes (5800–4500 BP) represents a unique opportunity to test this assumption for this region. Despite cultural similarities between riverine and coastal shellmounds, important ecological and site distribution differences are expected to impact on lifestyle. The purpose of this study is thus to document and interpret health and lifestyle indicators in Moraes in comparison to coastal shellmound groups. Specifically we test if the rare evidence of fish and mollusc remains in the riverine shellmound led to (a) higher caries rates and (b) lower auditory exostosis frequency and (c) if the small size of the riverine shellmound translates into reduced demographic density and thus rarity of communicable infectious diseases. Of the three hypotheses, (a) was confirmed, (b) was rejected and (c) was partly rejected. Bioanthropological similarities between Moraes and coastal shellmounds include auditory exostoses with equally high frequencies; significantly more frequent osteoarthritis in upper than in lower limbs; cranial and dental morphological affinities and low frequencies of violent trauma. However, there are also important differences: Moraes subsisted on a much broader protein diet and consumed more cariogenic food, but showed a stature even shorter than coastal groups. Thus, despite the contact also suggested by treponematoses in both site types, there was enough time for the people at the riverine site to adapt to local conditions

Die Bedeutung antiker Theorien für die Genese und Systematik von Kants Philosophie. Eine Analyse der drei Kritiken

Zusammenfassung von: Die Bedeutung antiker Theorien für die Genese und Systematik von Kants Philosophie. Eine Analyse der drei Kritiken. Kant ist viel mehr durch die hellenistische Philosophie (Stoizismus, Epikureismus, Skeptizismus) beeinflusst als durch Platon. Die These eines Platon-Einflusses wurde vor allem von Schopenhauer, Nietzsche und dem Neukantianismus vertreten.Aber Kants Platonverständnis ist das von Ciceros "Orator" oder Seneca. Kant hat Platon und Aristoteles nicht im Original gelesen, sondern bezog seine Informationen über Sekundärquellen. Mit der Lektüre lateinischer Autoren wie Cicero und Seneca hingegen war er aus der Schule vertraut. Durch die Gliederung der Arbeit anhand der Abfolge der kantischen Schriften ist es im Gegensatz zu einer an antiken Autoren orientierten Darstellung möglich, sowohl Konstanten des Umgangs Kants mit der Antike als auch charakteristische Unterschiede zu berücksichtigen. Der genaue Ort der Antike bei Kant kann folgendermaßen beschrieben werden: Sie ist an Stellen präsent, an denen Kant seine Philosophie im Sinnes eines bewussten Klassizismus stilisiert. Er denkt durchweg in Antithesen, deren Pole er mit "Leitautoren" besetzt: Epikur/Platon (schon bei Cicero), Epikur/Stoa, Aristoteles/Platon (seit Bonaventura, für Kant greifbar bei Leibniz). Allerdings entsteht Kants Philosophie nicht aus einer genuinen Auseinandersetzung mit der Antike: Kein antiker Autor, sondern Hume hat ihn "geweckt". Obwohl die kantische kritische Philosophie allgemein für "revolutionär" und "modern" gehalten wird, kann gezeigt werden, dass Kant sie auch für die abschließende Summe aller bisherigen Philosophie gehalten hat. Die "Technik der Natur" in der "Kritik der Urteilskraft" ist nicht aristotelisch, sondern stoisch. Die kann sowohl von der Wortwahl als auch von den philosophischen Implikationen her gezeigt werden. Die Arbeit ist in die folgenden fünf Teile gegliedert (Untereinteilungen werden hier ausgelassen): I Einleitung; das Thema; Absicht und Methode der vorliegenden Arbeit; Forschungslage; Grundsätzliches zu Kants Umgang mit der Philosophiegeschichte II Von der Dissertation (1770) bis zur "Kritik der reinen Vernunft" (1781/1787): Platon, Aristoteles, Epikur, Skepsis III Die "Grundlegung zur Metaphysik der Sitten" und die "Kritik der praktischen Vernunft" IV Die Antike im zweiten Teil der "Kritik der Urteilskraft", der "Kritik der teleologischen Urteilskraft" V Schlus

Effect of workplace- versus home-based physical exercise on pain in healthcare workers:study protocol for a single blinded cluster randomized controlled trial

BACKGROUND: The prevalence and consequences of musculoskeletal pain is considerable among healthcare workers, allegedly due to high physical work demands of healthcare work. Previous investigations have shown promising results of physical exercise for relieving pain among different occupational groups, but the question remains whether such physical exercise should be performed at the workplace or conducted as home-based exercise. Performing physical exercise at the workplace together with colleagues may be more motivating for some employees and thus increase adherence. On the other hand, physical exercise performed during working hours at the workplace may be costly for the employers in terms of time spend. Thus, it seems relevant to compare the efficacy of workplace- versus home-based training on musculoskeletal pain. This study is intended to investigate the effect of workplace-based versus home-based physical exercise on musculoskeletal pain among healthcare workers. METHODS/DESIGN: This study was designed as a cluster randomized controlled trial performed at 3 hospitals in Copenhagen, Denmark. Clusters are hospital departments and hospital units. Cluster randomization was chosen to increase adherence and avoid contamination between interventions. Two hundred healthcare workers from 18 departments located at three different hospitals is allocated to 10 weeks of 1) workplace based physical exercise performed during working hours (using kettlebells, elastic bands and exercise balls) for 5 × 10 minutes per week and up to 5 group-based coaching sessions, or 2) home based physical exercise performed during leisure time (using elastic bands and body weight exercises) for 5 × 10 minutes per week. Both intervention groups will also receive ergonomic instructions on patient handling and use of lifting aides etc. Inclusion criteria are female healthcare workers working at a hospital. Average pain intensity (VAS scale 0-10) of the back, neck and shoulder (primary outcome) and physical exertion during work, social capital and work ability (secondary outcomes) is assessed at baseline and 10-week follow-up. Further, postural balance and mechanical muscle function is assessed during clinical examination at baseline and follow-up. DISCUSSION: This cluster randomized trial will investigate the change in self-rated average pain intensity in the back, neck and shoulder after either 10 weeks of physical exercise at the workplace or at home. TRIAL REGISTRATION: ClinicalTrials.gov (NCT01921764)