The adaptive problem of absent third-party punishment

Language is a uniquely human behaviour, which has presented unique adaptive problems. Prominent among these is the transmission of information that may affect an individual’s reputation. The possibility of punishment of those with a low reputation by absent third parties has created a selective pressure on human beings that is not shared by any other species. This has led to the evolution of unique cognitive structures that are capable of handling such a novel adaptive challenge. One of these, we argue, is the propositional theory of mind, which enables individuals to model, and potentially manipulate, their own reputation in the minds of other group members, by representing the beliefs that others have about the first party’s intentions and actions. Support for our theoretical model is provided by an observational study on tattling in two preschools, and an experimental study of giving under threat of gossip in a dictator game

The Ages of Elliptical Galaxies from Infrared Spectral Energy Distributions

The mean ages of early-type galaxies obtained from the analysis of optical spectra, give a mean age of 8 Gyr at z = 0, with 40% being younger than 6 Gyr. Independent age determinations are possible by using infrared spectra (5-21 microns), which we have obtained with the Infrared Spectrograph on the Spitzer Observatory. This age indicator is based on the collective mass loss rate of stars, where mass loss from AGB stars produces a silicate emission feature at 9-12 microns. This feature decreases more rapidly than the shorter wavelength continuum as a stellar population ages, providing an age indicator. From observations of 30 nearby early-type galaxies, 29 show a spectral energy distribution dominated by stars and one has significant emission from the ISM and is excluded. The infrared age indicators for the 29 galaxies show them all to be old, with a mean age of about 10 Gyr and a standard deviation of only a few Gyr. This is consistent with the ages inferred from the values of M/L_B, but is inconsistent with the ages derived from the optical line indices, which can be much younger. All of these age indicators are luminosity-weighted and should be correlated, even if multiple-age components are considered. The inconsistency indicates that there is a significant problem with either the infrared and the M/L_B ages, which agree, or with the ages inferred from the optical absorption lines.Comment: Accepted for publication in Ap

Airborne observations of the infrared emission bands

Earlier airborne studies of the infrared bands between 5 and 8 microns have now been extended to a sample of southern sources selected from the IRAS Low Resolution Spectra (LRS) atlas. The correlation between the strongest bands at 6.2 and 7.7 microns is now based on a total sample of 40 sources and is very strong. A new emission band at 5.2 microns, previously predicted for polycyclic aromatic hydrocarbons (PAHs), is recognized in 27 sources; it too correlates with the dominant 7.7 micron band, showing that the 5.2 micron feature also belongs to the generic spectrum of PAH features at 3.3, 5.6, 6.2, 6.2, 7.7, 8.7, 11.3, and 12.7 microns. Sufficient sources are had now to define the relative strengths of most of these bands in three separate nebular environments: planetaries, H II regions, and reflection nebulae. Significant variations are detected in the generic spectra of PAHs in these different environments which are echoed by variations in the exact wavelength of the strong 7.7 micron peak. The earlier suggestion that, in planetaries, the fraction of total emission observed by IRAS that is carried by the PAH emissions is correlated with nebular gas-phase C/O ratio is supported by the addition of newly-observed southern planetaries, including the unusually carbon-rich (WC10) nebular nuclei. These (WC10) nuclei also exhibit a strong plateau of emission linking the 6.2 and 7.7 micron features

Diseño de un observador y un controlador de velocidad de un motor DC por modos deslizantes

En este artículo se presenta una estructura de estimación y control de estados mediante modos deslizantes para un modelo lineal. Se presenta un sistema mecánico de un Motor DC, al cual se le diseñaran un observador y un controlador deslizante de primer y segundo orden. Los resultados se comparan con un diseño de un PID. Los dos diseños se prueban ante cambios de referencia, perturbaciones y ruido. In this paper a structure for estimation and control of states using sliding modes is presented for a linear model. A mechanical system of a DC motor is presented with a designed observer and a sliding controller of first and second order. The results are compared with a design of a PID. The two designs are tested against reference changes, disturbances and noise. — In this paper a structure for estimation and control of states using sliding modes is presented for a linear model. A mechanical system of a DC motor is presented with a designed observer and a sliding controller of first and second order. The results are compared with a design of a PID. The two designs are tested against reference changes, disturbances and noise. Keywords — Dc Motor, Observer, Sliding modes, State spaceUniversidad Nacional de ColombiaColciencia

Some 5-13 micrometer airborne observations of Comet Wilson 1986l: Preliminary results

Comet Wilson was observed from the Kuiper Airborne Observatory approximately 23.6 and 25.7 Apr. 1987, UT (approx. 3 to 5 days after perihelion) using the NASA-Ames Faint Object Grating Spectrometer. Spectrophotometric data were observed with a 21 inch aperture between 5 and 13 micrometer and with a spectral resolution of 50 to 100. Spectra of the inner coma and nucleus reveal a fairly smooth continuum with little evidence of silicate emission. The 5 to 8 micrometer color temperature of the comet was 300 + or - 15 K, approx. 15 percent higher than the equilibrium blackbody temperature. All three spectra of the nucleus show a new emission feature at approx. 12.25 micrometer approx. two channels (.22 micrometer) wide. Visual and photographic observations made during the time of these observations showed a broad faint, possible two component tail. No outburst activity was observed

Diseño de un Observador y un Controlador de velocidad de un motor DC por modos deslizantes

En este artículo se presenta una estructura de estimación y control de estados implementando las normas básicas de diseño de observadores y controladores mediante modos deslizantes para un modelo lineal. Se presenta un sistema mecánico de un Motor DC, al cual se le diseñaran un observador y un controlador deslizante de primero y segundo orden. Los resultados se comparan con un diseño de un PID. Los dos diseños se prueban ante cambios de referencia, perturbaciones y ruido.Universidad Nacional de ColombiaColcienciasBanco Mundia

Borrowed alleles and convergence in serpentine adaptation

ACKNOWLEDGMENTS. We thank members of the L.Y. and K.B. laboratories for helpful discussions. This work was supported through the European Research Council Grant StG CA629F04E (to L.Y.); a Harvard University Milton Fund Award (to K.B.); Ruth L. Kirschstein National Research Service Award 1 F32 GM096699 from the NIH (to L.Y.); National Science Foundation Grant IOS-1146465 (to K.B.); NIH National Institute of General Medical Sciences Grant 2R01GM078536 (to D.E.S.); and Biotechnology and Biological Sciences Research Council Grant BB/L000113/1 (to D.E.S.)Peer reviewedPublisher PD

Argument for the incompleteness of quantum mechanics based on macroscopic and contextual realism: EPR and GHZ paradoxes with cat states

The Einstein-Rosen-Podolsky (EPR) paradox gives an argument for the incompleteness of quantum mechanics based on the premise of local realism. The general viewpoint is that the argument is compromised, because local realism is falsifiable by Bell or Greenberger-Horne-Zeilinger (GHZ) experiments. In this paper, we challenge this conclusion, by presenting alternative versions of the EPR paradox based on premises not falsifiable by the GHZ and Bell predictions. First, we explain how the Bohm-EPR and GHZ paradoxes can be demonstrated using macroscopic spins $S_\theta$ formed from qubits realized as two macroscopically distinct states. This establishes an 'all or nothing' incompatibility between quantum mechanics and macroscopic realism (MR). However, we note different definitions of MR. For a system in a superposition of two macroscopically distinct eigenstates of $S_\theta$, MR posits a definite value for the outcome of $S_\theta$. Deterministic macroscopic realism (dMR) posits MR regardless of whether the interaction $U_\theta$ determining the measurement setting $\theta$ has occurred. In contrast, the weaker assumption, weak macroscopic realism (wMR), posits MR for the system prepared after $U_\theta$. We show that the GHZ paradox negates dMR but is consistent with wMR. Yet, we show that a Bohm-EPR paradox for the incompleteness of quantum mechanics arises based on either form of MR. Since wMR is not falsified, this raises the question of how to interpret the EPR paradox. We revisit the original EPR paradox and find a similar result: The EPR argument can be based on a contextual version of local realism (wLR) not falsifiable by Bell or GHZ experiments. The premises wLR and wMR posit realism and no-disturbance for systems prepared with respect to a pointer basis (after $U_\theta$), leading to further predictions giving consistency with quantum mechanics

Relaxed States in Relativistic Multi-Fluid Plasmas

The evolution equations for a plasma comprising multiple species of charged fluids with relativistic bulk and thermal motion are derived. It is shown that a minimal fluid coupling model allows a natural casting of the evolution equations in terms of generalized vorticity which treats the fluid motion and electromagnetic fields equally. Equilibria can be found using a variational principle based on minimizing the total enstrophy subject to energy and helicity constraints. A subset of these equilibria correspond to minimum energy. The equations for these states are presented with example solutions showing the structure of the relaxed states.Comment: 8 pages, 2 figure

Spectral structure near the 11.3 micron emission feature

If the 11.3 micron emission feature seen in the spectra of many planetary nebulae, H II regions, and reflection nebulae is attributable to polycyclic aromatic hydrocarbons (PAHs), then additional features should be present between 11.3 and 13.0 microns. Moderate resolution spectra of NGC 7027, HD 44179, BD+30 deg 3639, and IRAS 21282+5050 are presented which show evidence for new emission features centered near 12.0 and 12.7 microns. These are consistent with an origin from PAHs and can be used to constrain the molecular structure of the family of PAHs responsible for the infrared features. There is an indication that coronene-like PAHs contribute far more to the emission from NGC 7027 than to the emission from HD 44179. The observed asymmetric profile of the 11.3 micron band in all the spectra is consistent with the slight anharmonicity expected in the C-H out-of-plane bending mode in PAHs. A series of repeating features between 10 and 11 microns in the spectrum of HD 44179 suggests a simple hydride larger than 2 atoms is present in the gas phase in this object