1,006 research outputs found
Hydrologic Data Collection Program for New Mexico
The objective of this thesis is to present a program for the collection of basic hydrologic data for the state of New Mexico. It is an expansion of the existing program which currently becomes more inadequate with the progressively extensive use of the water resources of the state. The need for hydrologic data for planning and operation of water use and control structures far exceeds that obtained by the existing program.
Types of data reported upon are climatological, stream flow, ground water, quality of water, suspended sediment, snow cover and reservoir, valley and channel sedimentation. For the purposes presented herein the individual programs are listed by the five larger drainage basins within the state. These are the Rio Grande, the Pecos, the Canadian, the Gila and the San Juan rivers
Building Place Value Understanding Through Modeling and Structure
Place value is a concept in which students in elementary school struggle and instruction and curricular materials continue to introduce and teach place value in a disconnected fashion. This study introduced place value through a modeling perspective, focusing specifically on using the bar model to represent units and quantity. The investigation piloted a place value module highlighting the use of the bar model in four first grade classrooms with high percentages of diverse learners, many from low-income families and with limited English language proficiency. The results indicated students successfully described the differences between units of 1 and 10 and could build and describe numbers in their teens and twenties. Students’ vocabulary and understanding of place value improved over a three-week period, suggesting visual models can be used as an effective model to promote place value understanding
Five Key Ideas to Teach Fractions and Decimals with Understanding
The teaching of fractions and decimals is a significant challenge for many teachers due to the inherent difficulty of the topic for students as well as the lack of high-quality, modernized curricular materials. This article examines the key ideas of teaching fractions and decimals for understanding that are evident in the current research literature and the curricular materials and teaching strategies from high-achieving nations
Developing Mathematical Thinking: Changing Teachers’ Knowledge and Instruction
In the present research, we evaluated the effectiveness of a multi-year professional development program in mathematics for elementary teachers. Each year the program focused on a different domain of mathematics. We found the program increased teachers’ knowledge of (a) number and operations, (b) measurement and geometry, and (c) probability and statistics. We also examined the relation between mathematical knowledge and teaching practices. Across the three domains neither pretest nor posttest mathematical knowledge were related to classroom teaching practices. However, change in knowledge was positively related to six different dimensions of teaching practice for number and operations, and for measurement and geometry; and was positively related to four or six dimensions for probability and statistics. That is, those teachers with greater changes in knowledge demonstrated more effective instruction
The Effects of Professional Development on Elementary Students’ Mathematics Achievement
This paper describes the effects of a professional development (PD) program – Developing Mathematical Thinking – on student achievement. Six Title I elementary schools with similar demographics, within one school district, were chosen to participate as either a treatment or comparison school. Three schools were chosen to participate in professional development that incorporates effective PD recommendations. All the teachers had to participate in all aspects of the PD, thereby eliminating potential self-selection bias. Using the state standardized achievement test as the before and after measure, results suggest improved student performance after professional development was implemented over a two year period
Developing a Multi-Dimensional Early Elementary Mathematics Screener and Diagnostic Tool: The Primary Mathematics Assessment
There is a critical need to identify primary level students experiencing difficulties in mathematics to provide immediate and targeted instruction that remediates their deficits. However, most early math screening instruments focus only on the concept of number, resulting in inadequate and incomplete information for teachers to design intervention efforts. We propose a mathematics assessment that screens and provides diagnostic information in six domains that are important to building a strong foundation in mathematics. This article describes the conceptual framework and psychometric qualities of a web-based assessment tool, the Primary Math Assessment (PMA). The PMA includes a screener to identify students at risk for poor math outcomes and a diagnostic tool to provide a more in-depth profile of children’s specific strengths and weaknesses in mathematics. The PMA allows teachers and school personnel to make better instructional decisions by providing more targeted analyses
Resistant tissues of modern marchantioid liverworts resemble enigmatic Early Paleozoic microfossils
Absence of a substantial pretracheophyte fossil record for bryophytes (otherwise predicted by molecular systematics) poses a major problem in our understanding of earliest land-plant structure. In contrast, there exist enigmatic Cambrian–Devonian microfossils (aggregations of tubes or sheets of cells or possibly a combination of both) controversially interpreted as an extinct group of early land plants known as nematophytes. We used an innovative approach to explore these issues: comparison of tube and cell-sheet microfossils with experimentally degraded modern liverworts as analogues of ancient early land plants. Lower epidermal surface tissues, including rhizoids, of Marchantia polymorpha and Conocephalum conicum were resistant to breakdown after rotting for extended periods or high-temperature acid treatment (acetolysis), suggesting fossilization potential. Cell-sheet and rhizoid remains occurred separately or together depending on the degree of body degradation. Rhizoid break-off at the lower epidermal surface left rimmed pores at the centers of cell rosettes; these were similar in structure, diameter, and distribution to pores characterizing nematophyte cell-sheet microfossils known as Cosmochlaina. The range of Marchantia rhizoid diameters overlapped that of Cosmochlaina pores. Approximately 14% of dry biomass of Marchantia vegetative thalli and 40% of gametangiophores was resistant to acetolysis. Pre- and posttreatment cell-wall autofluorescence suggested the presence of phenolic compounds that likely protect lower epidermal tissues from soil microbe attack and provide dimensional stability to gametangiophores. Our results suggest that at least some microfossils identified as nematophytes may be the remains of early marchantioid liverworts similar in some ways to modern Marchantia and Conocephalum
By Shepherd, et all, posted on November 29th, 2013 in Articles, Climate
Earth is increasingly an “urbanized ” planet. The “World Population Clock ” registered a Population of 7,175,309,538 at 8:30 pm (LST) on Oct. 6, 2013. Current and future trends suggest that this population will increasingly reside in cities. Currently, 52 percent of the world population is urban, which means we are a majority “urbanized ” society. Figure 1 indicates this trend will continue, wit
Parallelization of Kinetic Theory Simulations
Numerical studies of shock waves in large scale systems via kinetic
simulations with millions of particles are too computationally demanding to be
processed in serial. In this work we focus on optimizing the parallel
performance of a kinetic Monte Carlo code for astrophysical simulations such as
core-collapse supernovae. Our goal is to attain a flexible program that scales
well with the architecture of modern supercomputers. This approach requires a
hybrid model of programming that combines a message passing interface (MPI)
with a multithreading model (OpenMP) in C++. We report on our approach to
implement the hybrid design into the kinetic code and show first results which
demonstrate a significant gain in performance when many processors are applied.Comment: 10 pages, 3 figures, conference proceeding
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