In his Preface the author' says that he started out to review all the more important theories upon the topics ordinarily discussed under human motivation but soon found himself more and more limited to the presentation of his own point of view. This very well characterizes the book. It is a very personal product. It is an outline with some defense of the author's own thinking about instincts and appetites and sentiments and how they function in human behavior. And as the author draws so heavily upon James and McDougall, especially the latter, the book may well be looked upon as a sort of sequel to their efforts. There is a thought-provoking distinction presented between instinct and appetite. An instinct is said to be aroused always by something in the external situation; and, correspondingly, an appetite is said to be aroused by sensations from within the body itself. This places, of course, a heavy emphasis upon the cognitive factor in all instinctive behaviors; and the author prefers to use the cognitive factor, especially the knowledge of that end-experience which will satisfy, as a means of differentiating one instinct from another. In this there is a recognized difference from McDougall who placed more emphasis for differentiation upon the emotional accompaniment. The list of instincts arrived at by this procedure is much like that of McDougall, although the author is forced by his criteria to present the possibility of food-seeking and sex and sleep operating both in the manner of an appetite and also as an instinct. The Shand-McDougall concept of sentiment is taken over and used in the explanation of moral motivation. There is the development within each personality of a sentiment for some moral principle. But this sentiment is not a very powerful motivating factor. It is reinforced by social pressures and by religion, which is treated as an effort of finite man to live in harmony with the infinite reality. Those whose psychological thinking is largely in terms of McDougall will doubtless find this volume a very satisfying expansion; but those who are at all inclined to support their psychological thinking by reference to experimental studies will not be so well pleased. The James-Lange theory, for example, is discussed without mention of the many experimental studies which it has provoked. Theoretical sources appear in general to be preferred to experimental investigations.

Human MotivationThe Mind in Action: A Study of Motives and Values. A. Campbell Garnett

Many problems in the experimental estimation of parameters for models can be solved through use of the likelihood ratio test. Applications of the likelihood ratio, with particular attention to photon counting experiments, are discussed. The procedures presented solve a greater range of problems than those currently in use, yet are no more difficult to apply. The procedures are proved analytically, and examples from current problems in astronomy are discussed.

Parameter estimation in astronomy through application of the likelihood ratio. [satellite data analysis techniques

A life-span theory of development is presented that is based on the concepts of primary and secondary control. Primary control refers to behaviors directed at the external environment and involves attempts to change the world to fit the needs and desires of the individual. Secondary control is targeted at internal processes and serves to minimize losses in, maintain, and expand existing levels of primary control. Secondary control helps the individual to cope with failure and fosters primary control by channeling motivational resources toward selected action goals throughout the life course. Primary control has functional primacy over secondary control. An analysis of extensive and diverse literatures spanning infancy through old age shows that trade-offs between primary and secondary control undergo systematic shifts across the life course in response to the opportunities and constraints encountered. In this article, we present a life-span theory of development based on the concept of control. Research on life-span development has become an increasingly active area of inquiry in the last two decades and has the potential of yielding fundamental theories about the emergence and transformation of human behavior over the life course (e.g., P. B. Baltes, 1987). However, as noted by Birren and Bengtson (1988), the field of life-course development and aging is at present best characterized as data rich but theory poor. Most existing developmental theories embrace limited temporal and functioning domains. With the exception of personality theorists such as Erikson, Loevinger, Gould, and Levinson (see Cavanaugh, 1990; Schulz & Ewen, 1993), psychologists have made few attempts to develop lifespan theories of development, in part because such efforts require the integration of information from multiple domains, including the behavioral, social, and biological sciences. A second formidable challenge posed by such an undertaking is the problem of level of analysis. Ideally, such a theory should explain both macro-level behaviors such as major life-course decisions

http://psycnet.apa.org/journals/rev/102/2/284.pdf

A life-span theory of control.

Neutron Stars 1: Equation of State and Structure

Young massive clusters are dense aggregates of young stars that form the fundamental building blocks of galaxies. Several examples exist in the Milky Way Galaxy and the Local Group, but they are particularly abundant in starburst and interacting galaxies. The few young massive clusters that are close enough to resolve are of prime interest for studying the stellar mass function and the ecological interplay between stellar evolution and stellar dynamics. The distant unresolved clusters may be effectively used to study the star-cluster mass function, and they provide excellent constraints on the formation mechanisms of young cluster populations. Young massive clusters are expected to be the nurseries for many unusual objects, including a wide range of exotic stars and binaries. So far only a few such objects have been found in young massive clusters, although their older cousins, the globular clusters, are unusually rich in stellar exotica. In this review we focus on star clusters younger than $\sim100$ Myr, more than a few current crossing times old, and more massive than $\sim10^4$ \Msun, irrespective of cluster size or environment. We describe the global properties of the currently known young massive star clusters in the Local Group and beyond, and discuss the state of the art in observations and dynamical modeling of these systems. In order to make this review readable by observers, theorists, and computational astrophysicists, we also review the cross-disciplinary terminology.

/pdf/young-massive-star-clusters-1mlfusxprp.pdf

Young Massive Star Clusters

There exists both theoretical and observational evidence that the magnetic field decay in neutron stars may proceed in a pronounced non--linear way during a certain episode of the neutron star's life. In the presence of a strong magnetic field the Hall--drift dominates the field evolution in the crust and/or the superfluid core of neutron stars. Analysing observations of $P$ and $\dot{P}$ for sufficiently old isolated pulsars we gain strong hints for a significantly non--linear magnetic field decay. Under certain conditions with respect to the geometry and strength of a large--scale magnetic background field an instability is shown to occur which rapidly raises small--scale magnetic field modes. Their growth rates increase with the background field strength and may reach $\sim 10^4$ times the ohmic decay rate. Consequences for the rotational and thermal evolution as well as for the cracking of the crust of neutron stars are discussed.

/pdf/non-linear-magnetic-field-decay-in-neutron-stars-theory-and-hozekgzpfl.pdf

Non--linear magnetic field decay in neutron stars -- Theory and observations

Context. We report on XMM-Newton observations of SN 1987 A in the Large Magellanic Cloud. Aims. The large collecting area telescopes together with the European Photon Imaging Cameras (EPIC) provide X-ray spectra with unprecedented statistical quality and make it possible to investigate the spectral evolution during the brightening observed since the discovery in X-rays. High resolution spectra from the Reflection Grating Spectrometers yield a complementary view and allow us to perform more detailed investigations of prominent emission lines. Methods. The X-ray spectra were modeled with two-temperature emission components from a hot plasma in collisional ionization equilibrium and in non-equilibrium (NEI). Results. We find a temperature for the equilibrium component of 0.24 ± 0.02 keV in January 2000 and April 2001 which increased to 0.30 ± 0.02 keV in May 2003 and also an indication for a temperature increase in the hot NEI component from ∼2 keV to ∼3 keV. Emission line ratios inferred from the RGS spectra suggest temperatures as low as 100 eV and an increase in the ionization state of oxygen and neon consistent with the observed temperature increases. The fast readout of the EPIC-pn instrument yields X-ray fluxes free of CCD pile-up effects which we used to normalize pile-up corrections for the published Chandra fluxes. The corrected X-ray light curve of SN 1987 A in the 0.5-2.0 keV energy band is best represented by a linear increase up to about day 4000 after the explosion and an exponential rise afterwards until the last published Chandra observation on day 6716. Modeling the light curve by emission from the inner ring which is approximated by a circular torus a central density n H = 1.15 x 10 4 cm -3 is found. In this model the forward shock has just passed the center of the torus. Conclusions. SN 1987 A continues to brighten exponentially in soft X-rays. The X-ray spectra can be represented by pure thermal emission without significant contribution from a compact object yet.

/pdf/xmm-newton-observations-of-sn-1987-a-56bem2rlm4.pdf

XMM-Newton observations of SN 1987 A

Aims. We study the stability/establishment of dipolar magnetostatic equilibrium configurations in new-born neutron stars (NSs) in dependence on the rotational velocity Ω and on the initial angle α between rotation and magnetic axis. Methods. The NS is modeled as a sphere of a highly magnetized (B ∼ 10 15 G) incompressible fluid of uniform density which rotates rigidly. For the initial dipolar background magnetic field, which defines the magnetic axis, two different configurations are assumed. We solve the 3D non-linear MHD equations by use of a spectral code. The problem in dimensionless form is completely defined by the initial field strength (for a fixed field geometry), the magnetic Prandtl number Pm, and the normalized rotation rate. The evolution of the magnetic and velocity fields is considered for initial magnetic field strengths characterized by the ratio of ohmic diffusion and initial Alfven travel times τOhm/τA,0 ≈ 1000, for Pm = 0.1, 1, 10, and the ratio of rotation period and initial Alfven travel time, P/τA,0 = 0.012, 0.12, 1.2, 12. Results. We find hints for the existence of a unique stable dipolar magnetostatic configuration for any specific α, independent of the initial field geometry. Comparing NSs possessing the same field structure at the end of their proto-NS phase, it turns out that sufficiently fast rotating NSs (P < 6 ms) with α < 45 ◦ retain their magnetar field, while the others lose almost all of their initial magnetic energy by transferring it into magnetic and kinetic energy of relatively small-scaled fields and continue their life as radio pulsars with a dipolar surface field of 10 12...13 G.

/pdf/magnetars-versus-radio-pulsars-mhd-stability-in-newborn-1i26baddx8.pdf

Magnetars versus Radio Pulsars: MHD Stability in Newborn Highly Magnetized Neutron Stars

Context. The non-linear Hall term present in the induction equation in the electron-magneto-hydrodynamics limit is responsible for the Hall drift of the magnetic field and, in some cases, for the so-called Hall instability. Aims. We investigate whether or not the growth rates and eigenfunctions found in the linear analysis are consistent with the results of non-linear numerical simulations. Methods. Following the linear analysis of Rheinhardt & Geppert, we study the same cases for which the Hall instability was predicted by solving the non-linear Hall induction equation using a two-dimensional conservative and divergence-free finite difference scheme that overcomes intrinsic difficulties of pseudo-spectral methods and can describe situations with arbitrarily high magnetic Reynolds numbers. Results. We show that unstable modes can grow to the level of the background field without being overwhelmed by the Hall cascade, and cause a complete rearrangement of the field geometry. We confirm both the growth rates and eigenfunctions found in the linearized analysis and hence the instability. In the non-linear regime, after the unstable modes grow to the background level, the naturally selected modes become stable and oscillatory. Later on, the evolution tends to select the modes with the longest possible wavelengths, but this process occurs on the magnetic diffusion timescale. Conclusions. We confirm the existence of the Hall instability. We argue against using the misleading terminology that associates the non-linear Hall term with a turbulent Hall cascade, since small-scale structures are not created everywhere. The field evolves instead in a Burgers-like manner, forms local structures with strong gradients which become shocks in the zero resistivity limit, and Hall waves are launched and propagated through the entire domain.

/pdf/confirmation-of-the-occurrence-of-the-hall-instability-in-302f4gbn4j.pdf

Confirmation of the occurrence of the Hall instability in the non-linear regime.

In former papers we showed that during the decay of a neutron star's magnetic field under the influence of the Hall drift, an unstable growth of small-scale field structures at the expense of the large-scale background field may happen. This linear stability analysis was based on the assumption of a uniform density throughout the neutron star crust, whereas in reality the density and all transport coefficients vary by many orders of magnitude. Here, we extend the investigation of the Hall drift induced instability by considering realistic profiles of density and chemical composition, as well as background fields with more justified radial profiles. Two neutron star models are considered differing primarily in the assumption on the core matter equation of state. For their cooling history and radial profiles of density and composition we use known results to infer the conductivity profiles. These were fed into linear calculations of a dipolar field decay starting from various initial configurations. At different stages of the decay, snapshots of the magnetic fields at the equator were taken to yield background field profiles for the stability analysis. Its main result is that the Hall instability may really occur in neutron star crusts. Characteristic growth times are in the order of $\la$$10^4\ldots10^6$ yrs depending on cooling age and background field strength. The influence of the equation of state and of the initial field configuration is discussed.

/pdf/the-occurrence-of-the-hall-instability-in-crusts-of-isolated-56gbzxc15e.pdf

Ulrich Geppert

Papers

Non--linear magnetic field decay in neutron stars -- Theory and observations

XMM-Newton observations of SN 1987 A

Magnetars versus Radio Pulsars: MHD Stability in Newborn Highly Magnetized Neutron Stars

Confirmation of the occurrence of the Hall instability in the non-linear regime.

The occurrence of the Hall instability in crusts of isolated neutron stars