Status and Conflict: A Sociological Perspective on the Urban Race Problem

Cohen’s intention here is to show how certain general principles of sociological theory can explain certain historical aspects of interracial behavior. Writing for a general, as distinct from a sociological, audience, Cohen analyzes effects of status and expectations in mixed-race interaction and shows how the theory can be used to overcome undesirable outcomes. At the time of this TR, the U.S. Civil Rights movements and many instances of violent repression and collective action were common news topics

Unitarity constraint for threshold coherent pion photoproduction on the deuteron and chiral perturbation theory

The contribution of the two-step process gamma + d -> p + n -> pi0 + d to the imaginary part of the amplitude for coherent pion production on the deuteron is calculated exploiting unitarity constraints. The result shows that this absorptive process is not negligible and has to be considered in an extraction of the elementary neutron production amplitude from the gamma + d -> pi0 + d cross section at threshold. In addition, it is argued that a consistent calculation of gamma + d -> pi0 + d in baryon chiral perturbation theory beyond next-to-leading order requires the inclusion of this absorptive process.Comment: 11 pages revtex including 2 postscript figure

Eliminating the Effects of a Status Characteristic

The authors propose a theory in which status generalization from a diffuse status characteristic such as age, race or gender can be eliminated by introducing contradictory information about a specific status characteristic such as task ability. They conducted an experimental test of the theory and found confirmation. The conclusions here differ from results of other experiments in which all status information combined and none was eliminated (including Technical Report #32 and Technical Report #35), and from the aggregation function proposed in the developing theory of status characteristics and expectation states (Berger et al. 1974; 1977)

Vestibular Activation Habituates the Vasovagal Response in the Rat

Vasovagal syncope is a significant medical problem without effective therapy, postulated to be related to a collapse of baroreflex function. While some studies have shown that repeated static tilts can block vasovagal syncope, this was not found in other studies. Using anesthetized, male Long–Evans rats that were highly susceptible to generation of vasovagal responses, we found that repeated activation of the vestibulosympathetic reflex (VSR) with ±2 and ±3 mA, 0.025 Hz sinusoidal galvanic vestibular stimulation (sGVS) caused incremental changes in blood pressure (BP) and heart rate (HR) that blocked further generation of vasovagal responses. Initially, BP and HR fell ≈20–50 mmHg and ≈20–50 beats/min (bpm) into a vasovagal response when stimulated with Sgv\S in susceptible rats. As the rats were continually stimulated, HR initially rose to counteract the fall in BP; then the increase in HR became more substantial and long lasting, effectively opposing the fall in BP. Finally, the vestibular stimuli simply caused an increase in BP, the normal sequence following activation of the VSR. Concurrently, habituation caused disappearance of the low-frequency (0.025 and 0.05 Hz) oscillations in BP and HR that must be present when vasovagal responses are induced. Habituation also produced significant increases in baroreflex sensitivity (p \u3c 0.001). Thus, repeated low-frequency activation of the VSR resulted in a reduction and loss of susceptibility to development of vasovagal responses in rats that were previously highly susceptible. We posit that reactivation of the baroreflex, which is depressed by anesthesia and the disappearance of low-frequency oscillations in BP and HR are likely to be critically involved in producing resistance to the development of vasovagal responses. SGVS has been widely used to activate muscle sympathetic nerve activity in humans and is safe and well tolerated. Potentially, it could be used to produce similar habituation of vasovagal syncope in humans

Introduction to a Theory of Group Structure and Information Exchange

This theoretical paper develops a framework for relationships between group structure and information exchange. Status orders among group members are important in situations that lack well-developed practices for work and clear criteria for evaluating outcomes.Preparation of this manuscript was supported in part by a grant from the National Science Foundation (IS 84/7948)

Interdependence, Interaction, and Productivity

Group tasks require communication, but communication can be excessive and time-wasting. The authors develop propositions group productivity and interaction. High reciprocal interdependence in teams requires high levels of interaction, but when interdependence is low, interaction can interfere with productivity. After developing appropriate measures of the variables, they tested that idea and related ideas with 224 R & D teams and found a strong relationship between communication and productivity on interdependent tasks.This research was supported by the Division of Industrial Science and Technological Innovation of the National Science Foundation under grant #IS1-8304340

Chiral Corrections to Lattice Calculations of Charge Radii

Logarithmic divergences in pion and proton charge radii associated with chiral loops are investigated to assess systematic uncertainties in current lattice determinations of charge radii. The chiral corrections offer a possible solution to the long standing problem of why present lattice calculations yield proton and pion radii which are similar in size.Comment: PostScript file only. Ten pages. Figures included. U. of MD Preprint #92-19

Chiral Extrapolations and Exotic Meson Spectrum

We examine the chiral corrections to exotic meson masses calculated in lattice QCD. In particular, we ask whether the non-linear chiral behavior at small quark masses, which has been found in other hadronic systems, could lead to large corrections to the predictions of exotic meson masses based on linear extrapolations to the chiral limit. We find that our present understanding of exotic meson decay dynamics suggests that open channels may not make a significant contribution to such non-linearities whereas the virtual, closed channels may be important.Comment: 13 pagers, 2 figure

Status Processes in Permanent Work Groups

This WP was published by Cohen and Zhou (1991).The research for this paper was supported by the National Science Foundation. The analysis was funded under N.S.F. grant number SES-8520248, Division of Social and Economic Sciences. The data were collected under N.S.F. Grant #ISI-8304340, Division of Industrial Science and Technological Innovation

Topics in Chiral Perturbation Theory

I consider some selected topics in chiral perturbation theory (CHPT). For the meson sector, emphasis is put on processes involving pions in the isospin zero S-wave which require multi-loop calculations. The advantages and shortcomings of heavy baryon CHPT are discussed. Some recent results on the structure of the baryons are also presented.Comment: 30 pp, TeX, Review talk, Third Workshop on High Energy Particle Physics (WHEPP III), Madras, India, January 1994. 7 figures available upon request. CRN--94/0