Race in the Life Sciences: An Empirical Assessment, 1950-2000

The mainstream narrative regarding the evolution of race as an idea in the scientific community is that biological understandings of race dominated throughout the nineteenth and twentieth centuries up until World War II, after which a social constructionist approach is thought to have taken hold. Many believe that the horrific outcomes of the most notorious applications of biological race—eugenics and the Holocaust—moved scientists away from thinking that race reflects inherent differences and toward an understanding that race is a largely social, cultural, and political phenomenon. This understanding of the evolution of race as a scientific idea informed the way that many areas of law conceptualize human equality, including civil rights, human rights, and constitutional law. This Article provides one of the first large-scale empirical assessments of publications in peer-reviewed biomedical and life science journals to examine whether biological theories of race actually lost credibility in the life sciences after World War II. We find that biological theories of race transformed yet persisted in the dominant academic discourse up through modern times—a finding that contradicts the central narrative that the life sciences became “color-blind” or “post-racial” several decades ago. The continued salience of biological race in the life sciences suggests that more attention needs to be paid to the questionable assumptions driving this research on biological race and its potential spillover effects, i.e., how persisting claims of biological race in the scientific literature might reconstitute its significance in law and society in a manner that may be harmful to racial minorities

Issues for computer modelling of room acoustics in non-concert hall settings

The basic principle of common room acoustics computer models is the energy-based geometrical room acoustics theory. The energy-based calculation relies on the averaging effect provided when there are many reflections from many different directions, which is well suited for large concert halls at medium and high frequencies. In recent years computer modelling has become an established tool in architectural acoustics design thanks to the advance in computing power and improved understanding of the modelling accuracy. However concert hall is only one of many types of built environments that require good acoustic design. Increasingly computer models are being sought for non-concert hall applications, such as in small rooms at low frequencies, flat rooms in workplace surroundings, and long enclosures such as underground stations. In these built environments the design issues are substantially difference from that of concert halls and in most cases the common room acoustics models will needed to be modified or totally re-formulated in order to deal with these new issues. This paper looks at some examples of these issues. In workplace environments we look at the issues of directional propagation and volume scattering by furniture and equipment instead of the surface scattering that is common assumed in concert hall models. In small rooms we look at the requirement of using wave models, such as boundary element models, or introducing phase information into geometrical room acoustics models to determine wave behaviours. Of particular interest is the ability of the wave models to provide phase information that is important not only for room modes but for the construction of impulse response for auralisation. Some simulated results using different modelling techniques will be presented to illustrate the problems and potential solutions

Conditional preparation of states containing a definite number of photons

A technique for conditionally creating single- or multimode photon-number states is analyzed using Bayesian theory. We consider the heralded N-photon states created from the photons produced by an unseeded optical parametric amplifier when the heralding detector is the time-multiplexed photon-number-resolving detector recently demonstrated by Fitch, et al. [Phys. Rev. A 68, 043814 (2003).] and simultaneously by Achilles, et al. [Opt. Lett. 28, 2387 (2003).]. We find that even with significant loss in the heralding detector, fields with sub-Poissonian photon-number distributions can be created. We also show that heralded multimode fields created using this technique are more robust against detector loss than are single-mode fields.Comment: 6 pages, 6 figures, reference added, typos corrected, content update

Next Generation Neutron Detection for Next Generation Nuclear Reactors

Track I: Power GenerationIncludes audio file (31 min.)As the demand for nuclear energy increases worldwide, and MO reactors come online, so does the availability of spent fuel that may be used as a medium of terror. That is, fuel for and waste or byproducts from fissile material refining and nuclear reactors (e.g. plutonium) pose a serious threat with respect to radiological dispersal and nuclear bomb detonation. Radiological dispersal can include fallout by means of water or atmospheric transport (e.g., dumping waste in a river) while fissile trafficking can include the transport of plutonium across a border by seaport entry. In order to safely increase the use of nuclear energy in Missouri, sensitive techniques for nuclear detection must be developed. Presently available commercial detectors are not sensitive enough to detect even large (~3kg) quantities of weapons grade plutonium that are hidden in a barrel of water; our borders are effectively open to critical mass sized plutonium transport. Profs. Caruso, Ching and Kruger (UMKC Physics) are developing detectors capable of a ten times increase in detection sensitivity over existing commercial detectors that will provide a critical component to the future Missouri nuclear safeguarding infrastructure

Single-Channel Signal Separation Using Spectral Basis Correlation with Sparse Nonnegative Tensor Factorization

A novel approach for solving the single-channel signal separation is presented the proposed sparse nonnegative tensor factorization under the framework of maximum a posteriori probability and adaptively fine-tuned using the hierarchical Bayesian approach with a new mixing mixture model. The mixing mixture is an analogy of a stereo signal concept given by one real and the other virtual microphones. An “imitated-stereo” mixture model is thus developed by weighting and time-shifting the original single-channel mixture. This leads to an artificial mixing system of dual channels which gives rise to a new form of spectral basis correlation diversity of the sources. Underlying all factorization algorithms is the principal difficulty in estimating the adequate number of latent components for each signal. This paper addresses these issues by developing a framework for pruning unnecessary components and incorporating a modified multivariate rectified Gaussian prior information into the spectral basis features. The parameters of the imitated-stereo model are estimated via the proposed sparse nonnegative tensor factorization with Itakura–Saito divergence. In addition, the separability conditions of the proposed mixture model are derived and demonstrated that the proposed method can separate real-time captured mixtures. Experimental testing on real audio sources has been conducted to verify the capability of the proposed method

Abundance And Ecological Significance Of The Clam Rangia Cuneata (Sowerby, 1831) In The Upper Barataria Estuary (Louisiana, USA)

We proposed that Rangia cuneata (Sowerby, 1831) is an important estuarine bivalve with ecological significance in three coastal lakes in Barataria Bay, Gulf of Mexico—Lake Cataouatche, Lake Salvador and Lac des Allemands. Our goals were to determine the abundance and distribution of Rangia in these lakes and to measure clearance times to elucidate its potential impacts on phytoplankton communities. The estimated average densities of R. cuneata in Lake Cataouatche, Lake Salvador, and Lac des Allemands were 63, 157, and 107 individuals m−2, respectively, which is 30% lower than that observed in nearby Lake Pontchartrain. The size of clams in Lake Salvador was between 4 and 50 mm, while individuals in Lake Cataouatche and Lac des Allemands were mostly \u3e20 mm. We postulate that a relatively infrequent large tropical storm transported the larvae from Lake Salvador to the other two lakes 1 year before our sampling to create this size difference. The clams were up to 99.9% of the total benthic biomass in Lake Salvador, 15.9% in Lake Cataouatche, and 40.0% in Lac des Allemands. The R. cuneata biomass values were between 16.2 and 27.6 g m−2 and the clearance times were 1.0–1.5 days. The clearance times are among the highest previously reported for coastal bivalve communities, which were from cooler climates. The results demonstrate that Rangia can be a critical part of the ecological processes in shallow water systems of the Gulf of Mexico

Size-Dependent Top-Down Control On Phytoplankton Growth By Microzooplankton In Eutrophic Lakes

We hypothesized that the grazing on phytoplankton by the microzooplankton community is size-dependent and, therefore, the top-down control on phytoplankton by microzooplankton community could be one possible mechanism explaining why small phytoplankton become less abundant than large phytoplankton in eutrophic waters. We tested this hypothesis using the dilution method to measure microzooplankton grazing rates and phytoplankton growth rates in the eutrophic waters of the Barataria estuary, southeastern Louisiana. Microzooplankton grazing rates on the slower growing, small phytoplankton (\5 lm) were higher than on the large phytoplankton ([20 lm) which had relatively faster growth rates. The proportional loss of the small, medium, large phytoplankton, and total phytoplankton community by microzooplankton grazing was 44, 53, 0, and 29%, respectively. The relative weakness of top-down grazing control on large phytoplankton by microzooplankton, and the relatively fast growth of large phytoplankton, may be why the average size of phytoplankton, whether isolated cells or colonies, tend to increase in these eutrophic waters and elsewhere