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Racial diversity among faculty, students, and administrators is increasing at universities in the United States. These changes have been uneven, with growth in underrepresented students exceeding that of faculty diversity. To address these and other inequities, a growing number of universities have established an executive‐level chief diversity officer (CDO). Our study offers a first empirical examination of this effort at selected 4‐year U.S. universities from 2001 to 2019 using unique data on the initial hiring date of a CDO and publicly available demographic data. We provide a comprehensive overview of demographic trends within our data and find confidence intervals around the estimated instantaneous average treatment effect for an executive‐level CDO on diverse hiring tightly contain zero. Estimated treatment effects are small and lack statistical significance within 4 years of a CDO position being established. We discuss other possible factors that explain trends toward higher diversity on campus and several possible constraints.

The significance of the bonus program Targeted Selective Reenlistment Bonus (TSRB) offered by the United States Army for its human resource management is discussed. The program has helped in increasing the number of soldiers reenlisting as well as those serving in undesirable locations. TSRB's feasibility in other large organizations is examined.

You wake up one morning to discover that your child is ill: His forehead feels hot to the touch, and his rapid breathing has a wheezing sound. You live in Malawi, where your health care options are few. When the local clinic opens, you wait for your turn with the solitary clinic worker. She's not a doctor, but she's been trained to identify and handle routine problems. [ABSTRACT FROM AUTHOR]

In previous work, we have proposed a dynamic, interactive system for conveying visual information via hearing and touch. The system is implemented with a touch screen that allows the user to interrogate a two-dimensional (2-D) object layout by active finger scanning while listening to spatialized auditory feedback. Sound is used as the primary source of information for object localization and identification, while touch is used both for pointing and for kinesthetic feedback. Our previous work considered shape and size perception of simple objects via hearing and touch. The focus of this paper is on the perception of a 2-D layout of simple objects with identical size and shape. We consider the selection and rendition of sounds for object identification and localization. We rely on the head-related transfer function for rendering sound directionality, and consider variations of sound intensity and tempo as two alternative approaches for rendering proximity. Subjective experiments with visually-blocked subjects are used to evaluate the effectiveness of the proposed approaches. Our results indicate that intensity outperforms tempo as a proximity cue, and that the overall system for conveying a 2-D layout is quite promising.

Polychlorinated biphenyl (PCB) levels and the factors affecting PCB accumulation in subadult and maturing Chinook salmon Oncorhynchus tshawytschafrom Puget Sound were characterized. Specifically, we (1) determined PCB levels in Chinook salmon from Puget Sound and compared them with levels in Chinook salmon from other West Coast populations, (2) determined whether PCB accumulation mainly occurred in the freshwater or marine habitats, and (3) quantified the relative importance of fish age, fish size (fork length), lipid content, and saltwater age (the number of winters spent in saltwater) on PCB concentration. The average PCB concentration measured in skinless muscle tissue samples of subadult and maturing Chinook salmon collected from Puget Sound was 53 ng/g (wet weight), which was 3-5 times higher than those measured in six other populations of Chinook salmon on the West Coast of North America. Concentrations in the Puget Sound samples varied from 10 to 220 ng/g. A comparison of PCB body burdens between subyearling smolts and returning adults revealed that almost all of the PCBs (>96%) were accumulated in the marine habitats. Surprisingly, although PCBs were mostly accumulated in marine habitats, PCB exposure was lowest in the largest fish that spent the most time in saltwater. Collectively, saltwater age, fish size, and lipids only accounted for 37% of the observed variation in PCB concentration, indicating that some other attribute of the fish's marine ecology accounted for the variation in PCB levels among Puget Sound Chinook salmon and for their elevated PCB levels relative to other West Coast populations. We hypothesized that residency in the contaminated Puget Sound environment was a major factor contributing to the higher and more variable PCB concentrations in these fish. This hypothesis was supported with an independent data set from a fishery assessment model, which estimated that 29% of subyearling Chinook salmon and 45% of yearling out-migrants from Puget Sound displayed resident behavior.

This paper describes simulations using fuzzy rules that show how Nash equilibrium behavior can be achieved by boundedly rational agents in two‐player games with infinite strategy spaces. That is, we show how agents using simple “rules of thumb” can achieve near‐equilibrium outcomes without any overt computation of the equilibrium. This is accomplished by using a genetic algorithm to approximate repeated play. Two games of differing complexities, both with analytic solutions, are examined: a repeated linear‐demand Cournot game and a contestable rent game. When fuzzy rules used only the most recent information, the games we examined converged to outcomes similar to their respective Coumot‐Nash equilibrium outcomes. When fuzzy rules “remembered” play from the more distant past, we found that the games converged more slowly, if at all.

Second‐order differential toroidal and unidirectional microphones derived using a bipolar first‐order differential sensor and a reflecting plane are described. The bipolar first‐order differential microphone is positioned with its axis perpendicular to and suspended a few centimeters from a large acoustically reflecting surface. The resulting sensor image is phase reversed resulting in a transducer that is a linear quadrupole. The linear quadrupole can be described by two dimensions, the distance corresponding to the dipole distance and twice the distance from the reflecting plane. If the reflecting surface is large enough or if the wall of a room is used, the resulting microphone becomes a second‐order differential unidirectional microphone. The match between the sensor and its image from a good acoustic reflector results in a second‐order differential microphone with 3‐dB beamwidth of ±33° and no grating lobes below 3 kHz for a 2.5‐cm spacing between the sensor and reflecting surface. A wall‐mounted toroid can be formed by using two bipolar first‐order sensors at right angles to each other and with the axis of each sensor at 45° to the reflecting surface and a spacing between transducers that is twice the height of the transducers from the reflecting plane. A table‐mounted toroid can be realized by properly combining a filtered version of a suspended first‐order sensor and an omnidirectional sensor flush mounted to the reflecting table top.

At a problem seminar in Ithaca, New York, during January 1969, James Eells raised the question (numbered 33 on the circulated list) of whether a paracompact Fréchet manifold admits a locally finite cover by open sets, all of whose intersections are contractible. This had been established in the separable case by David Henderson, who obtained star-finite covers. This note settles the case that the model space is a Banach space homeomorphic to its countably infinite Cartesian power. The cover elements and all nonempty intersections are homeomorphic to the model. A short proof that the nerve of the cover has the homotopy type of the manifold is also included.

The title statement is proved, and it is shown further that the subcontinua of a dendron actually form a Hilbert cube when (and only when) the branch points of the dendron are dense. Along the way, it is established that whenever a Hilbert cube manifold is compactified into a Hilbert cube factor by the addition of another Hilbert cube factor having Property Z in the compactification, then the resulting space is actually a Hilbert cube.

Let $ Q$ and $ P'$ $ P \times Q$ are homeomorphic. A consequence of this result is that the Cartesian product of a countable, locally finite simplicial complex with a separable, infinite-dimensional Fréchet space is a manifold modelled on the Fréchet space. It is also proved that a countably infinite product of nondegenerate spaces is a Hilbert cube provided that the product of each of the spaces with the Hilbert cube is a Hilbert cube. Together with the first result, this establishes that a countably infinite product of nondegenerate, compact, contractible polyhedra is a Hilbert cube. In addition, a proof is given of the (previously unpublished) theorem of R. D. Anderson that a countably infinite product of nondegenerate dendra is a Hilbert cube.

It is shown that if a locally finite-dimensional simplicial complex is given the ``barycentric'' metric, then its product with any Fréchet space X of suitably high weight is a manifold modelled on X, provided that X is homeomorphic to its countably infinite Cartesian power. It is then shown that if X is Banach, all paracompact X-manifolds may be represented (topologically) by such products.

Presents letters to the editors referencing articles and topics about politics and administration discussed in previous issues of The Nation. "Police Brutality," which focused on the incidents of police brutality in Union Square on March 6, 1930 in the U.S.; "There is a Conspiracy," which focused on the book publishing; and "Noble Motives," which focused on the reforms undertaken by President Herbert Hoover.

Directional microphones are best noted for their noise reduction properties in communication systems. Close‐talking differential microphones are particularly useful when the noise environment disturbs the ability to communicate without error, such as in public and cellular telephony, aircraft communications, etc. These differential microphones work best when they are placed within 1 cm from the lips of the talker where the sound field has a large gradient. For a plane‐wave sound field the sensitivity rises proportional to ωn, where n is the order of the difference. Users of differential microphones do not always correctly position the sensor at the proper distance from the mouth and therefore the sensitivity of the microphone may also rise proportional to ωn especially at high frequencies. A method is described of correcting for this high‐frequency gain without significantly degrading the noise canceling properties of first‐ and second‐order differential microphones.

A statement by Korenbaum [J. Acoust. Soc. Am. 91, XXX–XXX (1992)] referring to ‘‘ a more sophisticated choice’’ of a design parameter of directional gradient microphones is questioned.

Directional microphones are being used increasingly for teleconferencing in a variety of environmental conditions such as varying size and design of the rooms in which they function. However, little is known about the subjective effects of varying environments on the hypothetical improvements produced by these complex microphone systems. It is possible, but quite difficult and expensive, to directly test any proposed microphone system design in a variety of actual or experimental rooms. An alternative approach is use of computer simulation, both of the microphone system and the room environment. A complex microphone system can be modeled as a collection of point microphones distributed in space and summed with appropriate time delays. Established room simulation modeling methods were used. Combining both models together, with appropriate attention to spatial and time resolution of the microphone model, allows calculation of the impulse response of the complete structure, in an arbitrary room environment. The resulting impulse response can be used as a filter for speech. Results of such simulations are presented and compared with real room results.

Second‐order differential microphones provide an excellent means for obtaining a superdirectional response with frequency‐independent directivity and small size. By subtracting the output of two closely spaced first‐order differential dipole [cos(θ)] microphones, a linear quadrupole is obtained whose directivity pattern is cos2(θ). This particular directivity pattern is realized only when the microphones are in an acoustic free‐field. When differential systems are placed on or near a finite surface, the effects of diffraction and scattering can significantly modify the directional response relative to the free‐field conditions. Since most differential microphones in teleconferencing and business environments are placed on a desktop surface, it is important to understand the effects of diffraction on these systems. A second‐order differential microphone was constructed that has been tested for directivity fluctuation in the presence of a large reflecting surface. These experimental results match predicted theoretical patterns for diffraction on a hard disk. Further experimentation with varying surface treatment and different reflector geometries have given valuable insight into the effects of diffraction and scattering on differential microphones placed on a finite reflecting surface.