853 research outputs found
Measures of distance from a randomly located point to neighboring lattice points for rectangular and hexagonal point lattices Technical report no. 3
Probability density function and distribution function of distance from random point in polygon to the nearest corner in lattic
Abstracts of unpublished theses on the gifted child found in the School of Education Library at Boston University which were not included in the Gaffney thesis of 1958
Thesis (Ed.M.)--Boston UniversityAndrews, Charles Herbert. "A Survey of Curriculum Materials of Value for the Teaching of Gifted Elementary School Children in the Language Arts Area." Unpublished Ed. M. Thesis, Boston University School of Education, 1957. Problem. To determine the curriculum materials which should be included in an elementary school classroom devoted to the maximal effective teaching of gifted children in the language arts area. [TRUNCATED
A probability law obtained by compounding the Poisson and half-normal probability laws Technical report no. 4
Discrete probability law obtained by assuming Poisson variable parameter is distributed according to half-normal probability la
Some comments on certain technical aspects on geographic information systems Technical report no. 2
Two-dimensional machine language and spatial statistics for design and development of geographic information system
The Grey Areas : Ways Teachers Make Meaning of and Describe Enacting Professional Ethics
This dissertation explored the experiences of 12 classroom teachers making meaning of their ethical practice in K–12 schools. The study uncovered how these teachers identify and problematize ethical issues as they relate to their practice. Through semi-structured interviewing, participants’ experiences around ethical practice were recorded and analyzed using Gilligan’s (1982) Listening Guide. The data collected provides insight into how these teachers make meaning of their practices, a process characterized by a complex interplay amongst personal and professional beliefs around caring and protecting students and their needs, a sense of responsibility as employees to adhere to district and school policies, an obligation to uphold the standards of the teaching profession, and the contextualized pressures and expectations of their specific teaching communities. Overall, the study describes the ways in which participants make meaning of their ethical practice amidst the increasing demands of the standards movement and accountability-based reforms that have contextualized teachers lived daily experiences. In particular, in sharing their stories, this study brings to light many instances of K–12 teachers resisting these demands imposed in order to best support the learning and long-term development of their students. I aim to provide a nuanced view into how these teachers remain committed to carrying out what is in students’ best interests. Their efforts creatively and quietly resisting and negotiating the structural and human pressures imposed on them are heartwarming at times. Similarly, their struggles, anxieties, disappointments, distress, and fatigue are heartbreaking but offer a glimpse into how these educators are enacting ethical practice despite the challenging contexts of schools today
Analytical Results for the Statistical Distribution Related to Memoryless Deterministic Tourist Walk: Dimensionality Effect and Mean Field Models
Consider a medium characterized by N points whose coordinates are randomly
generated by a uniform distribution along the edges of a unitary d-dimensional
hypercube. A walker leaves from each point of this disordered medium and moves
according to the deterministic rule to go to the nearest point which has not
been visited in the preceding \mu steps (deterministic tourist walk). Each
trajectory generated by this dynamics has an initial non-periodic part of t
steps (transient) and a final periodic part of p steps (attractor). The
neighborhood rank probabilities are parameterized by the normalized incomplete
beta function I_d = I_{1/4}[1/2,(d+1)/2]. The joint distribution
S_{\mu,d}^{(N)}(t,p) is relevant, and the marginal distributions previously
studied are particular cases. We show that, for the memory-less deterministic
tourist walk in the euclidean space, this distribution is:
S_{1,d}^{(\infty)}(t,p) = [\Gamma(1+I_d^{-1})
(t+I_d^{-1})/\Gamma(t+p+I_d^{-1})] \delta_{p,2}, where t=0,1,2,...,\infty,
\Gamma(z) is the gamma function and \delta_{i,j} is the Kronecker's delta. The
mean field models are random link model, which corresponds to d \to \infty, and
random map model which, even for \mu = 0, presents non-trivial cycle
distribution [S_{0,rm}^{(N)}(p) \propto p^{-1}]: S_{0,rm}^{(N)}(t,p) =
\Gamma(N)/\{\Gamma[N+1-(t+p)]N^{t+p}\}. The fundamental quantities are the
number of explored points n_e=t+p and I_d. Although the obtained distributions
are simple, they do not follow straightforwardly and they have been validated
by numerical experiments.Comment: 9 pages and 4 figure
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Physical activity counseling in medical school education: a systematic review
Background: Despite a large evidence base to demonstrate the health benefits of regular physical activity (PA), few physicians incorporate PA counseling into office visits. Inadequate medical training has been cited as a cause for this. This review describes curricular components and assesses the effectiveness of programs that have reported outcomes of PA counseling education in medical schools. Methods: The authors systematically searched MEDLINE, EMBASE, PsychINFO, and ERIC databases for articles published in English from 2000 through 2012 that met PICOS inclusion criteria of medical school programs with PA counseling skill development and evaluation of outcomes. An initial search yielded 1944 citations, and 11 studies representing 10 unique programs met criteria for this review. These studies were described and analyzed for study quality. Strength of evidence for six measured outcomes shared by multiple studies was also evaluated, that is, students’ awareness of benefits of PA, change in students’ attitudes toward PA, change in personal PA behaviors, improvements in PA counseling knowledge and skills, self-efficacy to conduct PA counseling, and change in attitude toward PA counseling. Results: Considerable heterogeneity of teaching methods, duration, and placement within the curriculum was noted. Weak research designs limited an optimal evaluation of effectiveness, that is, few provided pre-/post-intervention assessments, and/or included control comparisons, or met criteria for intervention transparency and control for risk of bias. The programs with the most evidence of improvement indicated positive changes in students’ attitudes toward PA, their PA counseling knowledge and skills, and their self-efficacy to conduct PA counseling. These programs were most likely to follow previous recommendations to include experiential learning, theoretically based frameworks, and students’ personal PA behaviors. Conclusions: Current results provide some support for previous recommendations, and current initiatives are underway that build upon these. However, evidence of improvements in physician practices and patient outcomes is lacking. Recommendations include future directions for curriculum development and more rigorous research designs
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Phylogeography and population genetic structure of double-crested cormorants (Phalacrocorax auritus)
The Double-crested Cormorant (Phalacrocorax auritus) is a widespread, colonial, North American waterbird with bicoastal and inland distributions. Four subspecies have been described within North America corresponding to five geographic breeding regions: Interior and North Atlantic cormorants (P. a. auritus); Southeastern cormorants (P. a. floridanus); Alaskan cormorants (P. a. cincinnatus); and Pacific cormorants (P. a. albociliatus). Management strategies vary widely across the species' range according to local perceptions rather than relative population status. An understanding of population genetic structure is necessary for delineating appropriate management units.
We examined the genetic structure of Double-crested Cormorants across their range in the United States and Canada to quantify variation within and among breeding sites and to assess the status of traditional geographically defined subspecies. Sequences (700bp) from domains I and II of the mitochondrial control region were analyzed for 234 Double-crested Cormorants from 23 breeding sites. Variation was also examined at 8 microsatellite loci for 395 cormorants from the same 23 breeding sites. The mtDNA and
microsatellite data provided strong evidence that the Alaskan subspecies is genetically divergent from other populations in North America (net sequence divergence = 6.72%; ΦST for mtDNA control region = 0.738; FST for microsatellite loci = 0.05). Our data also suggested strong genetic divergence in the southwestern U.S.; southern California may represent a zone of introgression resulting from a northward expansion of a unique lineage from the species' range in northwestern Mexico. In contrast, there was little support for recognition of subspecies within the conterminous U.S. and Canada, outside of Alaska. Rather than genetically distinct regions corresponding to the putative subspecies, we observed a distribution of genetic variation consistent with a pattern of gradual isolation by distance. This pattern implies that genetic differences across the range are due to geographic distance rather than discrete subspecific breaks. Although three of the four subspecies were not genetically distinct, potential demographic separation, habitat differences, and recent declines at some colonies within the regions, suggests that the Pacific and possibly the North Atlantic breeding regions may still warrant consideration as distinct populations.
This thesis provides the first species-wide assessment of the phylogeography and population genetic structure of the Double-crested Cormorant. It further resulted in the first microsatellite markers developed specifically for a North American pelecaniform. The mitochondrial and microsatellite data provide a comprehensive assessment of the four putative subspecies described for the species. Given the highly varying conservation status of Double-crested Cormorants throughout their range, results of this study provide guidance for conservation and management practices on their behalf in North America
Revising upper-ocean sulfur dynamics near Bermuda : new lessons from 3 years of concentration and rate measurements
© The Author(s), 2015. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Environmental Chemistry 13 (2016): 302-313, doi:10.1071/EN15045.Oceanic biogeochemical cycling of dimethylsulfide (DMS), and its precursor dimethylsulfoniopropionate (DMSP), has gained considerable attention over the past three decades because of the potential role of DMS in climate mediation. Here we report 3 years of monthly vertical profiles of organic sulfur cycle concentrations (DMS, particulate DMSP (DMSPp) and dissolved DMSP (DMSPd)) and rates (DMSPd consumption, biological DMS consumption and DMS photolysis) from the Bermuda Atlantic Time-series Study (BATS) site taken between 2005 and 2008. Concentrations confirm the summer paradox with mixed layer DMS peaking ~90 days after peak DMSPp and ~50 days after peak DMSPp : Chl. A small decline in mixed layer DMS was observed relative to those measured during a previous study at BATS (1992–1994), potentially driven by long-term climate shifts at the site. On average, DMS cycling occurred on longer timescales than DMSPd (0.43 ± 0.35 v. 1.39 ± 0.76 day–1) with DMSPd consumption rates remaining elevated throughout the year despite significant seasonal variability in the bacterial DMSP degrader community. DMSPp was estimated to account for 4–5 % of mixed layer primary production and turned over at a significantly slower rate (~0.2 day–1). Photolysis drove DMS loss in the mixed layer during the summer, whereas biological consumption of DMS was the dominant loss process in the winter and at depth. These findings offer new insight into the underlying mechanisms driving DMS(P) cycling in the oligotrophic ocean, provide an extended dataset for future model evaluation and hypothesis testing and highlight the need for a reexamination of past modelling results and conclusions drawn from data collected with old methodologies.The authors acknowledge funding from the National Science Foundation
(NSF) (OCE-0425166) and the Center for Microbial Oceanography
Research and Education (CMORE) a NSF Science and Technology Center
(EF-0424599)
Environmental, biochemical and genetic drivers of DMSP degradation and DMS production in the Sargasso Sea
Author Posting. © The Author(s), 2011. This is the author's version of the work. It is posted here by permission of John Wiley & Sons for personal use, not for redistribution. The definitive version was published in Environmental Microbiology 14 (2012): 1210-1223, doi:10.1111/j.1462-2920.2012.02700.x.Dimethylsulfide (DMS) is a climatically relevant trace gas produced and cycled by the
surface ocean food web. Mechanisms driving intraannual variability in DMS production and
dimethylsulfoniopropionate (DMSP) degradation in open-ocean, oligotrophic regions were
investigated during a 10 month time-series at the Bermuda Atlantic Time-series Study site in the
Sargasso Sea. Abundance and transcription of bacterial DMSP degradation genes, DMSP lyase
enzyme activity, and DMS and DMSP concentrations, consumption rates, and production rates
were quantified over time and depth. This interdisciplinary dataset was used to test current
hypotheses of the role of light and carbon supply in regulating upper-ocean sulfur cycling.
Findings supported UV-A dependent phytoplankton DMS production. Bacterial DMSP
degraders may also contribute significantly to DMS production when temperatures are elevated
and UV-A dose is moderate, but may favor DMSP demethylation under low UV-A doses. Three
groups of bacterial DMSP degraders with distinct intraannual variability were identified and
niche differentiation was indicated. The combination of genetic and biochemical data suggest a
modified ‘bacterial switch’ hypothesis where the prevalence of different bacterial DMSP
degradation pathways is regulated by a complex set of factors including carbon supply,
temperature, and UV-A dose.This research was funded by National Science Foundation (NSF) grants OCE-
0525928, OCE-072417, and OCE-042516. Additional funding was provided by the NSF Center
for Microbial Oceanography Research and Education (CMORE), the Gordon and Betty Moore
Foundation, the Scurlock Fund, the Ocean Ventures Fund, a National Defense Science and
Engineering Graduate Fellowship, and an Environmental Protection Agency STAR Graduate
Fellowship
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