24 research outputs found
Deep MMT Transit Survey of the Open Cluster M37 III: Stellar Rotation at 550 Myr
In the course of conducting a deep (14.5 ~< r ~< 23), 20 night survey for
transiting planets in the rich ~550 Myr old open cluster M37 we have measured
the rotation periods of 575 stars which lie near the cluster main sequence,
with masses 0.2 Msun ~< M ~< 1.3 Msun. This is the largest sample of rotation
periods for a cluster older than 500 Myr. Using this rich sample we investigate
a number of relations between rotation period, color and the amplitude of
photometric variability. Stars with M >~ 0.8 Msun show a tight correlation
between period and mass with heavier stars rotating more rapidly. There is a
group of 4 stars with P > 15 days that fall well above this relation, which, if
real, would present a significant challenge to theories of stellar angular
momentum evolution. Below 0.8 Msun the stars continue to follow the period-mass
correlation but with a broad tail of rapid rotators that expands to shorter
periods with decreasing mass. We combine these results with observations of
other open clusters to test the standard theory of lower-main sequence stellar
angular momentum evolution. We find that the model reproduces the observations
for solar mass stars, but discrepancies are apparent for stars with 0.6 ~< M ~<
1.0 Msun. We also find that for late-K through early-M dwarf stars in this
cluster rapid rotators tend to be bluer than slow rotators in B-V but redder
than slow rotators in V-I_{C}. This result supports the hypothesis that the
significant discrepancy between the observed and predicted temperatures and
radii of low-mass main sequence stars is due to stellar activity.Comment: Replaced with version accepted to ApJ. 104 pages, 7 tables, 26
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Neurocranium versus Face: A Morphometric Approach with Classical Anthropometric Variables for Characterizing Patterns of Cranial Integration in Extant Hominoids and Extinct Hominins
The relative importance of the two main cranial complexes, the neurocranium and the splanchnocranium, has been examined in the five species of extant hominoids and in a huge sample of extinct hominins using six standard craniometric variables that measure the length, width and height of each cranial module. Factor analysis and two-block partial least squares were used for establishing the major patterns of developmental and evolutionary integration between both cranial modules. The results obtained show that all extant hominoids (including the anatomically modern humans) share a conserved pattern of developmental integration, a result that agrees with previous studies. The pattern of evolutionary integration between both cranial modules in australopiths runs in parallel to developmental integration. In contrast, the pattern of evolutionary and developmental integration of the species of the genus Homo is the opposite, which is probably the consequence of distinctive selective regimes for both hominin groups.JAPC, JMJA and PP received fundings from Ministerio de Ciencia e Innovación, Gobierno de España (http://www.idi.mineco.gob.es), project CGL2011-30334, and Consejería de Economía, Innovación, Ciencia y Empleo, Junta de Andalucía, España (http://www.juntadeandalucia.es/organismos/economiainnovacioncienciayempleo.html), project P11-HUM-7248 and Research Groups RNM-146 and HUM-607
Noncomparabilities & Non Standard Logics
Many normative theories set forth in the welfare economics, distributive justice and cognate literatures posit noncomparabilities or incommensurabilities between magnitudes of various kinds. In some cases these gaps are predicated on metaphysical claims, in others upon epistemic claims, and in still others upon political-moral claims. I show that in all such cases they are best given formal expression in nonstandard logics that reject bivalence, excluded middle, or both. I do so by reference to an illustrative case study: a contradiction known to beset John Rawls\u27s selection and characterization of primary goods as the proper distribuendum in any distributively just society. The contradiction is avoided only by reformulating Rawls\u27s claims in a nonstandard form, which form happens also to cohere quite attractively with Rawls\u27s intuitive argumentation on behalf of his claims
Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.
BACKGROUND: As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. METHODS: We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. RESULTS: A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44 814 patients with a median hospital stay of 4 (range 2-7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. CONCLUSIONS: Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care. STUDY REGISTRATION: ISRCTN5181700