Recent occurrence of Cylindrospermopsis raciborskii, in Waikato lakes of New Zealand.

Cylindrospermopsis raciborskii is a toxin-producing species of cyanobacteria that in autumn 2003 was recorded for the first time in three shallow (max. depth ≤5 m) Waikato lakes and a hydro-electric dam on the Waikato River, New Zealand. It formed water blooms at densities >100 000 cells/ml in Lakes Waahi and Whangape. Net rates of population growth >0.2 day-1 were recorded for C. raciborskii in Lakes Ngaroto, Waahi, and Karapiro, based on comparisons of low numbers (detection of cells/ml) from initial samples and its presence at bloom densities (>15 000 cells/ml) in the subsequent sample "x"-"y" days later. C. raciborskii may be well adapted to rapid proliferation in the Waikato lakes, which are eutrophic to hypertrophic, with high light attenuation, and where nitrogen (N) fixation may provide it with a competitive advantage over non-nitrogen fixing algae under N-limited conditions

Commensurability oscillations due to pinned and drifting orbits in a two-dimensional lateral surface superlattice

We have simulated conduction in a two-dimensional electron gas subject to a weak two-dimensional periodic potential, $V_x \cos(2\pi x/a) + V_y \cos(2\pi y/a)$. The usual commensurability oscillations in $\rho_{xx}(B)$ are seen with $V_x$ alone. An increase of $V_y$ suppresses these oscillations, rather than introducing the additional oscillations in $\rho_{yy}(B)$ expected from previous perturbation theories. We show that this behavior arises from drift of the guiding center of cyclotron motion along contours of an effective potential. Periodic modulation in the magnetic field can be treated in the same way.Comment: 3 pages text, 4 eps figures, revte

Affine extended weak order is a lattice

Coxeter groups are equipped with a partial order known as the weak Bruhat order, such that $u \leq v$ if the inversions of $u$ are a subset of the inversions of $v$. In finite Coxeter groups, weak order is a complete lattice, but in infinite Coxeter groups it is only a meet semi-lattice. Matthew Dyer introduced a larger poset, now known as extended weak order, which contains the weak Bruhat order as an order ideal and coincides with it for finite Coxeter groups. The extended weak order is the containment order on certain sets of positive roots: those which satisfy a geometric condition called "biclosed". The finite biclosed sets are precisely the inversion sets of Coxeter group elements. Dyer conjectured that the extended weak order is always a complete lattice, even for infinite Coxeter groups. In this paper, we prove Dyer's conjecture for Coxeter groups of affine type. To do so, we introduce the notion of a clean arrangement, which is a hyperplane arrangement where the regions are in bijection with biclosed sets. We show that root poset order ideals in a finite or rank 3 untwisted affine root system are clean. We set up a general framework for reducing Dyer's conjecture to checking cleanliness of certain subarrangements. We conjecture this framework can be used to prove Dyer's conjecture for all Coxeter groups.Comment: 29 pages, 11 figures, comments welcom

Distances to the high galactic latitude molecular clouds G192-67 and MBM 23-24

We report on distance determinations for two high Galactic latitude cloud complexes, G192-67 and MBM 23-24. No distance determination exists in the literature for either cloud. Thirty-four early type stars were observed towards the two clouds, more than half of which have parallaxes measured by the Hipparcos satellite. For the remaining stars we have made spectroscopic distance estimates. The data consist of high resolution echelle spectra centered on the Na I D lines, and were obtained over six nights at the Coude Feed telescope at Kitt Peak National Observatory. Interstellar absorption lines were detected towards some of the stars, enabling estimates of the distances to the clouds of 109 +/- 14 pc for G192-67, and of 139 +/- 33 pc for MBM 23-24. We discuss the relationship of these clouds to other ISM features such as the Local Hot Bubble and the local cavity in neutral hydrogen.Comment: 15 pages, 6 embedded figures, to be published in the ApJ Vol. 516, No.

Predicting New Product Success or Failure: A Comparison of U.S. and U.K. Practices

We propose a model that allows managers to assess new product development (NPD) projects, combined with the anticipated strategy, prior to introduction and to estimate a probability of success. This model allows for an evaluation and prioritization of resource commitments. A test of this model that compares companies within the United States (U.S.) and the United Kingdom (U.K.) is provided

Modeling Soil Water Contents and Their Effects on Stream Flow in Kentucky

Soil water contents of eight important soil series in Kentucky were measured periodically during the summer growing season for four years, 1977 through 1980. The soils divided into three groups according to their behavior. The first group (Maury and Crider) is well-drained and never showed excess water above field capacity at any time during the four seasons. The second group (Zanesville, Lowell, Calloway, Grenada and Shelbyville) showed perched water tables at times, especially during the early part of the growing season. The third group was represented by the Huntington soil which has a permanent water table. The in-situ field capacity or upper limits was determined on numerous samples of the Maury, Crider and Shelbyville soil series. Variation within series was rather low, indicating that samples taken at one site are representative of the soil in general. A model for estimating the soil water in each 15 cm layer was developed and proved to work very well with both Maury and Crider soils. Lowell soil was predicted poorly by the model, with other soils being intermediate. A variation of the model which assumed that the lowest layer of the Huntington was always at the upper limit due to a permanent water table also worked well. The water calculated from the model as deep drainage was used as a measure of increase in streamflow and compared to measured streamflow on three watersheds and four soils in 1978 and 1979. The R2 values ranged from 0.41 to 0.95 and the slope, which ideally should be 1.0, ranged from 0.54 to 1.36. The quantitative measure of streamflow was not satisfactory but the prediction of events was quite good. Modifications in the model that seem to be required include provisions for evaporation from foliage with small rains, higher evapotranspiration at lower soil water contents, less deep drainage with small rains and an aquifer storage factor

Snapshot 2005: Where the American Public Stands on Terrorism and Preparedness Four Years after September 11

The National Center for Disaster Preparedness (NCDP) 2005 survey of the American public’s attitudes and views on terrorism, preparedness, and associated issues is the latest in a series of national surveys administered annually beginning in the months after September 11, 2001. The survey was completed in July 2005, just after the London Underground bombings and just before Hurricane Katrina. NCDP commissioned national and New York City public opinion polls in the immediate aftermath of September 11, 2001 to gauge the American public’s views and attitudes on a wide range of topics germane to disaster preparedness and emergency events. Since the first polls which were completed 3 and 6-months after September 11, 2001, NCDP has annually commissioned a survey which goes to the field in July-August, just before the anniversary of September 11. The 2005 survey was the fourth annual. Each survey includes trended questions as well as “one-off” questions appropriate to the given time period. Trended questions include confidence in government; willingness and ability to evacuate; personal and family preparedness plans; personal sacrifice; community preparedness; perceptions and engagement of all-hazard preparedness; and other questions thematic with the afore listed.. All questions are cross-tabulated with a variety of demographics including race, age, gender, income, region, size of community, political affiliation, and education. Further, select questions establishing a division of respondent (e.g. those having personal and family preparedness plans versus those who do not) are cross-tabulated with other selected questions to observe correlations. (e.g. awareness of community preparedness plans). The surveys are developed by NCDP investigators in conjunction with Marist, who administers the survey, codes the data, and produces the frequency tables. Full data and trend tables are available on request

Alternative Splicing of AMPA Subunits in Prefrontal Cortical Fields of Cynomolgus Monkeys Following Chronic Ethanol Self-Administration

Functional impairment of the orbital and medial prefrontal cortex underlies deficits in executive control that characterize addictive disorders, including alcohol addiction. Previous studies indicate that alcohol alters glutamate neurotransmission and one substrate of these effects may be through the reconfiguration of the subunits constituting ionotropic glutamate receptor (iGluR) complexes. Glutamatergic transmission is integral to cortico-cortical and cortico-subcortical communication and alcohol-induced changes in the abundance of the receptor subunits and/or their splice variants may result in critical functional impairments of prefrontal cortex in alcohol dependence. To this end, the effects of chronic ethanol self-administration on glutamate receptor ionotropic AMPA (GRIA) subunit variant and kainate (GRIK) subunit mRNA expression were studied in the orbitofrontal cortex (OFC), dorsolateral prefrontal cortex (DLPFC), and anterior cingulate cortex (ACC) of male cynomolgus monkeys. In DLPFC, total AMPA splice variant expression and total kainate receptor subunit expression were significantly decreased in alcohol drinking monkeys. Expression levels of GRIA3 flip and flop and GRIA4 flop mRNAs in this region were positively correlated with daily ethanol intake and blood ethanol concentrations (BEC) averaged over the 6 months prior to necropsy. In OFC, AMPA subunit splice variant expression was reduced in the alcohol treated group. GRIA2 flop mRNA levels in this region were positively correlated with daily ethanol intake and BEC averaged over the 6 months prior to necropsy. Results from these studies provide further evidence of transcriptional regulation of iGluR subunits in the primate brain following chronic alcohol self-administration. Additional studies examining the cellular localization of such effects in the framework of primate prefrontal cortical circuitry are warranted

An Analysis of Masked Bobwhite Collection Locales and Habitat Characteristics

We evaluated the collecting locales of 251 masked bobwhite (Colinus virginianus ridgwayi) specimens in museum collections. Eighteen were from 4 sites in Arizona—all collected by Herbert Brown. The vast majority (93%) of specimens were from the Mexican State of Sonora. We visited and photographed each of the Arizona collection locations and most of the sites in Sonora. Collector descriptions indicate the bird’s principal habitat affiliations were with tall grass-weed (1⁄4 forb) pastures, savannas, and farm fields. All historic localities visited were either in grass-forb habitats along drainages or in present or former savannas adjacent to woody cover and/or agricultural fields between 240 and 1,060 m elevation. These sites were remarkably similar to other bobwhite habitats in subtropic-tropic South Texas and Oaxaca, Mexico. Masked bobwhite habitat was a diverse tropic-subtropic grassland within or adjacent to dense woody cover (thornscrub) and/or farmland. These habitats experienced alterations and loss of the tall grass-weed component due to livestock husbandry. Some former habitat sites appear to have recovered, however, and restoration of the subspecies might be possible if suitable stock exists. Unfortunately, this bird may now be functionally extinct