Hands-On Physical Science for In-Service Teachers

The initiation of the Virginia Commonwealth University B.S. in Science program was reported in this journal Fall 1999 as a program designed to meet the academic content major of a teacher preparation program for elementary and middle school mathematics and science teachers [1]. This paper reports the current status of the interdisciplinary B.S. in Science degree program including program enrollment data and trends. Also described are refinements in the required curriculum, which include a newly developed geometry, a mathematical computing course, and an emerging teaching technology course featuring graphing calculators, CBLs, and computer software applications

Sustaining entrepreneurial business: a complexity perspective on processes that produce emergent practice

This article examines the management practices in an entrepreneurial small firm which sustain the business. Using a longitudinal qualitative case study, four general processes are identified (experimentation, reflexivity, organising and sensing), that together provide a mechanism to sustain the enterprise. The analysis draws on concepts from entrepreneurship and complexity science. We suggest that an entrepreneur’s awareness of the role of these parallel processes will facilitate their approaches to sustaining and developing enterprises. We also suggest that these processes operate in parallel at multiple levels, including the self, the business and inter-firm networks. This finding contributes to a general theory of entrepreneurship. A number of areas for further research are discussed arising from this result

Corporate contact tracing as a pandemic response

Since the start of the COVID-19 pandemic, a steady stream of propositions from tech giants and start-ups alike has furnished us with the idea that GPS- or Bluetooth-enabled contact tracing apps are a vital part of the pandemic response. This commentary considers these apps as ‘corporate contact tracing’, emphasizing the private-sector role that such developments imply. We first discuss corporate contact tracing’s potential to de-center the power of public health authorities. Then, using the frames of surveillance capitalism and disaster capitalism, we suggest how corporate contact tracing might feed the rise of corporate power in the public sphere. We question its capacity to address structural inequalities and to foster a social justice vision of public health. And, we wonder whether corporate contact tracing might intensify the effects of discriminatory design and algorithmic oppression. We conclude by calling for a discussion of this technology beyond questions of privacy and efficacy

Separable and Low-Rank Continuous Games

In this paper, we study nonzero-sum separable games, which are continuous games whose payoffs take a sum-of-products form. Included in this subclass are all finite games and polynomial games. We investigate the structure of equilibria in separable games. We show that these games admit finitely supported Nash equilibria. Motivated by the bounds on the supports of mixed equilibria in two-player finite games in terms of the ranks of the payoff matrices, we define the notion of the rank of an n-player continuous game and use this to provide bounds on the cardinality of the support of equilibrium strategies. We present a general characterization theorem that states that a continuous game has finite rank if and only if it is separable. Using our rank results, we present an efficient algorithm for computing approximate equilibria of two-player separable games with fixed strategy spaces in time polynomial in the rank of the game

Genetic Sampling of Palmer\u27s Chipmunks in the Spring Mountains, Nevada

Palmer\u27s chipmunk (Neotamias palmeri) is a medium-sized chipmunk whose range is limited to the higherelevation areas of the Spring Mountain Range, Nevada. A second chipmunk species, the Panamint chipmunk (Neotamias panamintinus), is more broadly distributed and lives in lower-elevation, primarily pinyon-juniper (Pinus monophylla-Juniperus osteosperma) habitat types. Panamint chipmunks are not closely related to Palmer\u27s, but field identification of the 2 species is unreliable. Palmer\u27s chipmunk is a species of concern in the state of Nevada and is listed by the International Union for Conservation of Nature (IUCN) as endangered. As such, conservation of Palmer\u27s chipmunks is a priority in the Spring Mountains National Recreation Area. We sampled putative Palmer\u27s chipmunks from 13 sites distributed across the Spring Mountains during 2010–2011. We removed Panamint chipmunks by using DNA-based identifications and then analyzed the genetic population structure of Palmer\u27s chipmunks by using a panel of 9 microsatellites. Of the 228 samples that were genotyped, 186 were Palmer\u27s; there was no evidence of hybridization between species. Four sites had exclusively Panamint chipmunks, 5 had exclusively Palmer\u27s chipmunks, and 3 had a mixture of the 2 species. In this study, Palmer\u27s chipmunks were exclusively captured at sites above 2400 m elevation, and Panamint chipmunks were exclusively captured at sites below 2200 m. Panamint chipmunks were trapped in areas typed as pinyon-juniper, but they were also trapped at sites typed as ponderosa pine (Pinus ponderosa) and mixed conifer. Both species were trapped at 3 sites; at all 3 sites, the lowerelevation traps contained Panamint chipmunks and the higher ones Palmer\u27s chipmunks. Population structure within Palmer\u27s chipmunks was minimal: heterozygosity was relatively high, and the populations displayed no signs of recent bottlenecks. Indications are that the distribution of Palmer\u27s chipmunk is limited to higher-elevation areas in the Spring Mountains, but within this area, Palmer\u27s chipmunk occurs as a single, large, well-connected, and stable population

Something’s Fishy: A Genetic Investigations Of Sculpin Species In Western Montana

Sculpin (Cottus spp.) are small, cryptic, bottom-dwelling fish native to cool and coldwater systems throughout North America. Although three species of primarily streamdwelling sculpin are thought to occur in Montana (one of which is a species of concern), their taxonomy, distribution, and origin are not well understood. In western Montana, the present distribution of sculpin species may have been shaped by both historical events, e.g., the Columbian Ice Sheet, and contemporary landscape changes (passage barriers, climate change, pollution, etc.). To evaluate sculpin presence, and species diversity, we analyzed sculpins from river drainages throughout western Montana—the Clark Fork, Blackfoot, Flathead, Bitterroot, Kootenai, Gallatin, Madison, and Missouri—east and west of the Continental Divide. We analyzed 135 samples at the mitochondrial DNA COXI gene and at 11 microsatellite DNA loci. Preliminary results of genetic analysis suggest the presence of four distinct species with hybridization among three of the species in some locations. Hybridization led to uncertainty in species designations based on morphology, but even genetically pure fish were occasionally misidentified. One species may represent an undescribed taxon that is limited in its distribution to the St. Regis drainage, although its relation to sculpin in Idaho is unknown. A second species, previously thought to be Cottus bairdii, is distinct from that taxon and is distributed on both sides of the Continental Divide

Analysis of Collectivism and Egoism Phenomena within the Context of Social Welfare

Comparative benefits provided by the basic social strategies including collectivism and egoism are investigated within the framework of democratic decision-making. In particular, we study the mechanism of growing "snowball" of cooperation.Comment: 12 pages, 5 figures. Translated from Russian. Original Russian Text published in Problemy Upravleniya, 2008, No. 4, pp. 30-3

Dual-barrel conductance micropipet as a new approach to the study of ionic crystal dissolution kinetics

A new approach to the study of ionic crystal dissolution kinetics is described, based on the use of a dual-barrel theta conductance micropipet. The solution in the pipet is undersaturated with respect to the crystal of interest, and when the meniscus at the end of the micropipet makes contact with a selected region of the crystal surface, dissolution occurs causing the solution composition to change. This is observed, with better than 1 ms time resolution, as a change in the ion conductance current, measured across a potential bias between an electrode in each barrel of the pipet. Key attributes of this new technique are: (i) dissolution can be targeted at a single crystal surface; (ii) multiple measurements can be made quickly and easily by moving the pipet to a new location on the surface; (iii) materials with a wide range of kinetics and solubilities are open to study because the duration of dissolution is controlled by the meniscus contact time; (iv) fast kinetics are readily amenable to study because of the intrinsically high mass transport rates within tapered micropipets; (v) the experimental geometry is well-defined, permitting finite element method modeling to allow quantitative analysis of experimental data. Herein, we study the dissolution of NaCl as an example system, with dissolution induced for just a few milliseconds, and estimate a first-order heterogeneous rate constant of 7.5 (±2.5) × 10–5 cm s–1 (equivalent surface dissolution flux ca. 0.5 μmol cm–2 s–1 into a completely undersaturated solution). Ionic crystals form a huge class of materials whose dissolution properties are of considerable interest, and we thus anticipate that this new localized microscale surface approach will have considerable applicability in the future