3,377 research outputs found

    School Site Visits: What can we learn from choice schools in Milwaukee?

    Get PDF
    The School Site Visits study is part of the fifth series of annual reports produced by the School Choice Demonstration Project (SCDP). It describes some of the major challenges experienced and common practices demonstrated by thirteen (13) K-12 schools participating in the Milwaukee Parental Choice Program (MPCP). During the 2010-11 school year, there were 107 religious and secular schools participating in the MPCP. This report is based on visits to six of the high schools and seven K-8 schools that collectively reflect the wide range of characteristics associated with participating schools. This includes whether schools scored above or below average on the 2010-11 Wisconsin Knowledge and Concepts Examinations in math and reading. Teams of researchers from the SCDP conducted one-day visits to each school during the spring and fall of 2011. Using a variety of interview, survey and observation instruments, the research teams gathered information about school practices in six general areas: (1) school culture, (2) student academic success, (3) effective leadership, (4) teacher quality, (5) religious integration and accommodation, and (6) school facilities. We use the data collected during the visits to describe the most common challenges the schools face and the common practices and strategies they use to overcome these challenges. Overall, a number of general lessons were learned

    Linear response functions for a vibrational configuration interaction state

    Get PDF
    Linear response functions are implemented for a vibrational configuration interaction state allowing accurate analytical calculations of pure vibrational contributions to dynamical polarizabilities. Sample calculations are presented for the pure vibrational contributions to the polarizabilities of water and formaldehyde. We discuss the convergence of the results with respect to various details of the vibrational wave function description as well as the potential and property surfaces. We also analyze the frequency dependence of the linear response function and the effect of accounting phenomenologically for the finite lifetime of the excited vibrational states. Finally, we compare the analytical response approach to a sum-over-states approac

    VERTICAL HAND FORCE AND FOREARM EMG DURING A HIGH-STEP ROCK-ON CLIMBING MOVE WITH' AND WITHOUT ADDED MASS

    Get PDF
    Eight experienced climbers completed four trials of a climbing movement known to climbers as a high-step rock-on on a vertical ind.oor wall. Climbers performed 2 trials of each condition of body mass (BM) and body mass plus 4.5 kg of added mass (AM). Two force platforms (FP) were imbedded into the wall flush with the climbing surface and modified to accept artificial climbing holds. During the movement sequence, a point was attained when all. weight was supported by the right foot and right hand on the two FP. Vertical ground reaction force (Fv) and forearm EMG were recorded at 500 Hz throughout the movement. Peak Fv was significantly higher for AM vs BM. Also peak Fv was higher than Fv at peak IEMG. There were no differences in IEMG. Added weight increases the support maintained by the hand, but, is not related to in IEMG at the point of peak force

    Farnesol restores wild-type colony morphology to 96% of \u3ci\u3eCandida albicans\u3c/i\u3e colony morphology variants recovered following treatment with mutagens

    Get PDF
    Candida albicans is a diploid fungus that undergoes a morphological transition between budding yeast, hyphal, and pseudohyphal forms. The morphological transition is strongly correlated with virulence and is regulated in part by quorum sensing. Candida albicans produces and secretes farnesol that regulates the yeast to mycelia morphological transition. Mutants that fail to synthesize or respond to farnesol could be locked in the filamentous mode. To test this hypothesis, a collection of C. albicans mutants were isolated that have altered colony morphologies indicative of the presence of hyphal cells under environmental conditions where C. albicans normally grows only as yeasts. All mutants were characterized for their ability to respond to farnesol. Of these, 95.9% fully or partially reverted to wildtype morphology on yeast malt (YM) agar plates supplemented with farnesol. All mutants that respond to farnesol regained their hyphal morphology when restreaked on YM plates without farnesol. The observation that farnesol remedial mutants are so common (95.9%) relative to mutants that fail to respond to farnesol (4.1%) suggests that farnesol activates and (or) induces a pathway that can override many of the morphogenesis defects in these mutants. Additionally, 9 mutants chosen at random were screened for farnesol production. Two mutants failed to produce detectable levels of farnesol. Candida albicans est un champignon diploïde qui subit une transition morphologique entre les levures en herbe, les hyphes et les formes pseudohyphales. La transition morphologique est fortement corrélée à la virulence et est régulée en partie par la détection du quorum. Candida albicans produit et sécrète du farnésol qui régule la transition morphologique levure-mycélium. Les mutants qui ne parviennent pas à synthétiser ou à répondre au farnésol pourraient être verrouillés en mode filamenteux. Pour tester cette hypothèse, une collection de mutants de C. albicans a été isolée qui ont modifié les morphologies des colonies, indiquant la présence de cellules hyphales dans des conditions environnementales où C. albicans ne pousse normalement que sous forme de levures. Tous les mutants ont été caractérisés pour leur capacité à répondre au farnésol. Parmi ceux-ci, 95,9% sont entièrement ou partiellement revenus à la morphologie de type sauvage sur des plaques de gélose au levure de malt (YM) complétées par du farnésol. Tous les mutants qui répondent au farnésol ont retrouvé leur morphologie hyphale lorsqu\u27ils ont été recréés sur des plaques YM sans farnésol. L\u27observation selon laquelle les mutants curatifs du farnésol sont si communs (95,9%) par rapport aux mutants qui ne répondent pas au farnésol (4,1%) suggère que le farnésol s\u27active et (ou) induit une voie qui peut supplanter bon nombre des défauts de morphogenèse de ces mutants. De plus, 9 mutants choisis au hasard ont été testés pour la production de farnésol. Deux mutants n\u27ont pas réussi à produire des niveaux détectables de farnésol

    Inoculum Size Effect in Dimorphic Fungi: Extracellular Control of Yeast-Mycelium Dimorphism in \u3ci\u3eCeratocystis ulmi\u3c/i\u3e

    Get PDF
    We studied the inoculum size effect in Ceratocystis ulmi, the dimorphic fungus that causes Dutch elm disease. In a defined glucose-proline-salts medium, cells develop as budding yeasts when inoculated at \u3e106 spores per ml and as mycelia when inoculated at type, age of the spores, temperature, pH, oxygen availability, trace metals, sulfur source, phosphorous source, or the concentration of glucose or proline. Similarly, it was not influenced by added adenosine, reducing agents, methyl donors, amino sugars, fatty acids, or carbon dioxide. Instead, growing cells excreted an unknown quorum-sensing factor that caused a morphological shift from mycelia to budding yeasts. This yeast-promoting effect is abolished if it is extracted with an organic solvent such as ethyl acetate. The quorum-sensing activity acquired by the organic solvent could be added back to fresh medium in a dosedependent fashion. The quorum-sensing activity in C. ulmi spent medium was specific for C. ulmi and had no effect on the dimorphic fungus Candida albicans or the photomorphogenic fungus Penicillium isariaeforme. In addition, farnesol, the quorum-sensing molecule produced by C. albicans, did not inhibit mycelial development of C. ulmi when present at concentrations of up to 100 μM. We conclude that the inoculum size effect is a manifestation of a quorum-sensing system that is mediated by an excreted extracellular molecule, and we suggest that quorum sensing is a general phenomenon in dimorphic fungi

    An objective framework to test the quality of candidate indicators of good environmental status

    Get PDF
    Large efforts are on-going within the EU to prepare the Marine Strategy Framework Directive's (MSFD) assessment of the environmental status of the European seas. This assessment will only be as good as the indicators chosen to monitor the 11 descriptors of good environmental status (GEnS). An objective and transparent framework to determine whether chosen indicators actually support the aims of this policy is, however, not yet in place. Such frameworks are needed to ensure that the limited resources available to this assessment optimize the likelihood of achieving GEnS within collaborating states. Here, we developed a hypothesis-based protocol to evaluate whether candidate indicators meet quality criteria explicit to the MSFD, which the assessment community aspires to. Eight quality criteria are distilled from existing initiatives, and a testing and scoring protocol for each of them is presented. We exemplify its application in three worked examples, covering indicators for three GEnS descriptors (1, 5, and 6), various habitat components (seaweeds, seagrasses, benthic macrofauna, and plankton), and assessment regions (Danish, Lithuanian, and UK waters). We argue that this framework provides a necessary, transparent and standardized structure to support the comparison of candidate indicators, and the decision-making process leading to indicator selection. Its application could help identify potential limitations in currently available candidate metrics and, in such cases, help focus the development of more adequate indicators. Use of such standardized approaches will facilitate the sharing of knowledge gained across the MSFD parties despite context-specificity across assessment regions, and support the evidence-based management of European seas

    Long photoperiods sustain high pH in Arctic kelp forests

    Get PDF
    Concern on the impacts of ocean acidification on calcifiers, such as bivalves, sea urchins, and foraminifers, has led to efforts to understand the controls on pH in their habitats, which include kelp forests and seagrass meadows. The metabolism of these habitats can lead to diel fluctuation in pH with increases during the day and declines at night, suggesting no net effect on pH at time scales longer than daily. We examined the capacity of subarctic and Arctic kelps to up-regulate pH in situ and experimentally tested the role of photoperiod in determining the capacity of Arctic macrophytes to up-regulate pH. Field observations at photoperiods of 15 and 24 hours in Greenland combined with experimental manipulations of photoperiod show that photoperiods longer than 21 hours, characteristic of Arctic summers, are conducive to sustained up-regulation of pH by kelp photosynthesis. We report a gradual increase in pH of 0.15 units and a parallel decline in pCO2 of 100 parts per million over a 10-day period in an Arctic kelp forest over midsummer, with ample scope for continued pH increase during the months of continuous daylight. Experimental increase in CO2 concentration further stimulated the capacity of macrophytes to deplete CO2 and increase pH. We conclude that long photoperiods in Arctic summers support sustained up-regulation of pH in kelp forests, with potential benefits for calcifiers, and propose that this mechanism may increase with the projected expansion of Arctic vegetation in response to warming and loss of sea ice.The study was funded by the Danish Environmental Protection Agency within the Danish Cooperation for Environment in the Arctic. It is also a contribution to the Greenland Ecosystem Monitoring program (www.G-E-M.dk) and the Arctic Science Partnership (www.asp-net.org). M.S.-M. was supported by a Fundación “La Caixa” fellowship (Spain). We acknowledge support by the CSIC Open Access Publication Initiative through its Unit of Information Resources for Research (URICI).Peer reviewe
    corecore