Questions: What is the mechanism of bog ground layer colonization post‐fire? Is species colonization stochastic or does facilitation occur?
Location: Boreal bog peatland near Crow Lake, Alberta, ...Canada.
Methods: Diaspore‐addition treatments were applied in 2003 to autoclaved peat samples from high and low microtopographic positions within a recently burned bog. Colonization was assessed within the plots in 2005 and compared to control plots to determine treatment success and patterns of colonization.
Results: A significant degree of ground layer colonization was found two years after fire, with Polytrichum strictum dominating the site. Colonization was greater in low (wet) plots, although only P. strictum and Sphagnum angustifolium had significant colonization. No effect of diaspore addition was observed and Sphagnum was only found in conjunction with P. strictum.
Conclusions: Environmental conditions and species life history strategy are more important than diaspore availability for post‐fire colonization. True mosses (e.g. P. strictum) appearto facilitate Sphagnum colonization.
The upper crustal location of the foci of the Spitak earthquake of December 7, 1988, and its aftershocks is proved. It is demonstrated that the seismological network in Armenia and Georgia allowed ...unequivocal focal depth identification based on the kinematic data. The waveforms of all the Spitak earthquakes are typical of sources in the upper crust. It is noted that up to now, mantle earthquakes in the Caucasus have only been revealed in the Terek–Sunzha depression.
Oral Cancer in Swedish Snuff Dippers HIRSCH, Jan M; WALLSTRÖM, Mats; CARLSSON, Anders-Petter ...
Anticancer research,
08/2012, Letnik:
32, Številka:
8
Journal Article
Recenzirano
Over recent decades there has been debate over whether or not Swedish snuff is carcinogenic in humans. Animal studies and molecular biological and experimental studies have shown the carcinogenic ...potential of Swedish snuff, but this has not been proved in prospective randomized studies. We present a case series of patients with oral squamous cell carcinomas diagnosed at the sites where the patients had used Swedish snuff for several years. Sixteen male patients were referred to and treated at Oral and Maxillofacial Surgery Departments and Ear, Nose and Throat clinics at seven different hospitals in Sweden. The mean age of the patients at the time of diagnosis was 72.9 years and the mean time of snuff use prior to cancer diagnosis was 42.9 years. This case series shows that Swedish snuff may not be a harmless alternative to smoking.
Drawing Upon Lessons Learned Swanson, Julie Dingle
The Gifted child quarterly,
07/2016, Letnik:
60, Številka:
3
Journal Article
Recenzirano
Javits Gifted and Talented Education Program has provided a wealth of knowledge on culturally and linguistically diverse (CLD) gifted learners and how to support teachers in their work with CLD ...students. This study examined five impactful Javits projects through qualitative inquiry centered on how innovative practice takes root or not. Using grounded theory tradition, examination of Javits project participation enabled insight into how educators act and react to innovation as well as their perceptions of CLD student impacts. Data sources (documents, conversations with principal investigators, and interviews with 14 educators) provide evidence for what sustains effective, research-based practices and explores continued student benefits. Major findings are (a) context matters in sustaining innovation, (b) powerful curriculum and instruction can transform teaching and teachers, and (c) student impacts continue. Data point to leadership as an underlying element in sustaining innovation. Leaders ensure that innovation extends from broad-based goals; they develop innovation through scale-up and involvement of others; they purposefully track results. Growing effective approaches is critical to access and opportunity and CLD-gifted learners’ talent development.
Charge injection and generation mechanisms under intense electric fields (up to 109 V m−1 ) in mineral oil are assessed experimentally and numerically. For this, current-voltage characteristics under ...positive and negative polarities are measured in a needle-plane configuration using sharp needles (with tip radius Rtip ≤ 1.1 m). In addition, a state of the art electro-hydrodynamic (EHD) model is implemented to calculate the contribution of the different mechanisms on the high-field conduction currents in the liquid. In order to evaluate exclusively the contribution of field emission, experiments are also performed in vacuum. It is found that neither field emission nor field ionisation can explain the conduction currents measured in mineral oil. It is proposed that field molecular ionisation, as described by Zener tunnelling model for solids, and electron impact ionisation are the processes dominating the generation of excess electron-ion pairs in mineral oil under positive and negative polarity, respectively. It is also shown that Zener molecular ionisation alone grossly overestimates the measured currents when parameters previously suggested in the literature for mineral oil are used. Preliminary model parameters for these mechanisms that best fit the conduction currents measured in mineral oil are presented and discussed.
Shareholder welfare (also addressed as shareholder primacy and shareholder value in the corporate governance and economics theory literature, and here used interchangeably with the more generic term ...shareholder welfare) has been fortified in the present regime of investor capitalism and is today widely normalized and taken for granted. However, when examining the theoretical tenets, operative methodologies, and stated preferences regarding the virtues of efficiency as a primary economic objective, and wider assumptions regarding alleged costs generated in the corporate system on the basis of managerial discretion and extant corporate legislation and court rulings, the advocacy of the benefits of shareholder welfare is compromised considerably; i. e., it is based on unjustified preferences and far from irrefutable propositions. Tracing the roots of agency theory and its forceful defence of shareholder welfare back to Chicago economics price theory and its application in law and economics scholarship, instituted in the early 1960s, theoretical inconsistencies in the predominant corporate governance model are demonstrated, accompanied by empirical materials that discredit the claim that the market for corporate control can replace, at low cost, the management discretion governance model. The study thus contributes to the critique of the role of shareholder welfare advocacy in investor capitalism.
This paper reexamines whether higher cigarette taxes will substantially reduce youth smoking. We study the impact of taxes during exactly the period in adolescence in which most smokers start their ...habits. We find weak or nonexistent tax effects in models of the onset of smoking between eighth and twelfth grades, models of the onset of heavy smoking between eighth and twelfth grades, and discrete‐time hazard models that include state fixed effects. We also provide a new perspective on the relationship between smoking and schooling: students who eventually drop out of school are already more likely to smoke in the eighth grade.
Taiwan is only one of four consolidated Asian democracies. Democratizing Taiwan provides the most comprehensive analysis of Taiwan's peaceful democratization including the past authoritarian ...experience, leadership both within and outside government, popular protest and elections, and constitutional interpretation and amendments.
The resources available to parents and the actions parents can take to further their children's education is reviewed through a collection of essays that focus on the social and economic resources of ...the family and by looking into the home, community, and school to see how families are involved in educational activities. The importance of parent involvement in learning that is not formally tied to the school is stressed. Information for the studies came from the National Education Longitudinal Study of 1988, a national random sample of 26,000 eighth graders and their parents, teachers, and school administrators. The following chapters are included: (1) "Parents, Their Children, and Schools: An Introduction" (Barbara Schneider); (2) "Parent Involvement in the Home, School, and Community" (Chandra Muller and David Kerbow); (3) "Family Structure Effects on Student Outcomes" (Seh-Ahn Lee); (4) "Parent Involvement and Academic Achievement: An Analysis of Family Resources Available to the Child" (Chandra Muller); (5) "Parental Intervention in the School: The Context of Minority Involvement" (David Kerbow and Annette Bernhardt); and (6) "Parent Choice and Inequality" (James S. Coleman, Kathryn S. Schiller, and Barbara Schneider). (Contains 47 tables, 21 figures, and 65 references.) (SLD)
PDF
