172 research outputs found
Use of Web-Based Technology to Enhance Instruction of Virginia\u27s Seventh and Eighth Grade Geometry Standards of Learning.
The purpose of this thesis is to develop web-based modules for enhancing instruction of the geometry sections of the Virginia Standards of Learning in the seventh and eighth grades. While all of Virginia\u27s seventh and eighth grade Standards of Learning strands are certainly worthy of these types of modules, geometry appeals to me most because of the vast amount of web-based resources that will be valuable when organized into modules. It is my hope that teachers of these grades will find this useful in their instruction of geometry
Recommended from our members
Matrix modification for enhancing the transport properties of the human cartilage endplate to improve disc nutrition.
Poor solute transport through the cartilage endplate (CEP) impairs disc nutrition and could be a key factor that limits the success of intradiscal biologic therapies. Here we demonstrate that treating the CEP with matrix metalloproteinase-8 (MMP-8) reduces the matrix constituents that impede solute uptake and thereby improves nutrient diffusion. Human CEP tissues harvested from four fresh cadaveric lumbar spines (age range: 38-66 years old) were treated with MMP-8. Treatment caused a dose-dependent reduction in sGAG, localized reductions to the amount of collagen, and alterations to collagen structure. These matrix modifications corresponded with 16-24% increases in the uptake of a small solute (376 Da). Interestingly, the effects of MMP-8 treatment depended on the extent of non-enzymatic glycation: treated CEPs with high concentrations of advanced glycation end products (AGEs) exhibited the lowest uptake compared to treated CEPs with low concentrations of AGEs. Moreover, AGE concentrations were donor-specific, and the donor tissues with the highest AGE concentrations appeared to have lower uptake than would be expected based on the initial amounts of collagen and sGAG. Finally, increasing solute uptake in the CEP improved cell viability inside diffusion chambers, which supports the nutritional relevance of enhancing the transport properties of the CEP. Taken together, our results provide new insights and in vitro proof-of-concept for a treatment approach that could improve disc nutrition for biologic therapy: specifically, matrix reduction by MMP-8 can enhance solute uptake and nutrient diffusion through the CEP, and AGE concentration appears to be an important, patient-specific factor that influences the efficacy of this approach
Ocean acidification alters predator behaviour and reduces predation rate
Ocean acidification poses a range of threats to marine invertebrates; however, the emerging and likely widespread effects of rising carbon dioxide (COâ) levels on marine invertebrate behaviour are still little understood. Here, we show that ocean acidification alters and impairs key ecological behaviours of the predatory cone snail Conus marmoreus. Projected near-future seawater COâ levels (975 ”atm) increased activity in this coral reef molluscivore more than threefold (from less than 4 to more than 12 mm minâ»Âč) and decreased the time spent buried to less than one-third when compared with the present-day control conditions (390 ”atm). Despite increasing activity, elevated COâ reduced predation rate during predatorâprey interactions with control-treated humpbacked conch, Gibberulus gibberulus gibbosus; 60% of control predators successfully captured and consumed their prey, compared with only 10% of elevated COâ predators. The alteration of key ecological behaviours of predatory invertebrates by near-future ocean acidification could have potentially far-reaching implications for predatorâprey interactions and trophic dynamics in marine ecosystems. Combined evidence that the behaviours of both species in this predatorâprey relationship are altered by elevated COâ suggests food web interactions and ecosystem structure will become increasingly difficult to predict as ocean acidification advances over coming decades
Ocean acidification alters predator behaviour and reduces predation rate
Ocean acidification poses a range of threats to marine invertebrates; however, the emerging and likely widespread effects of rising carbon dioxide (COâ) levels on marine invertebrate behaviour are still little understood. Here, we show that ocean acidification alters and impairs key ecological behaviours of the predatory cone snail Conus marmoreus. Projected near-future seawater COâ levels (975 ”atm) increased activity in this coral reef molluscivore more than threefold (from less than 4 to more than 12 mm minâ»Âč) and decreased the time spent buried to less than one-third when compared with the present-day control conditions (390 ”atm). Despite increasing activity, elevated COâ reduced predation rate during predatorâprey interactions with control-treated humpbacked conch, Gibberulus gibberulus gibbosus; 60% of control predators successfully captured and consumed their prey, compared with only 10% of elevated COâ predators. The alteration of key ecological behaviours of predatory invertebrates by near-future ocean acidification could have potentially far-reaching implications for predatorâprey interactions and trophic dynamics in marine ecosystems. Combined evidence that the behaviours of both species in this predatorâprey relationship are altered by elevated COâ suggests food web interactions and ecosystem structure will become increasingly difficult to predict as ocean acidification advances over coming decades
Microfabrication Lab Furnace Upgrade
This project, undertaken by the Mechanical Engineering Department at California Polytechnic State University, aimed to upgrade the control system, user interface, and control software for Cal Poly\u27s oxidation and diffusion furnaces. The upgrade was designed to enhance the usability of the furnaces for students learning in the microfabrication lab and improve the lab\u27s image for prospective students. The project involved a comprehensive design process, including mechanical design, controls, software, human factors, heat transfer, fluid mechanics, electrical design, integration, and testing. The implementation phase entailed procurement of over 300 distinct components, manufacturing, and assembly.
The project\u27s primary goal was to ensure safety and reliability, considering the operational conditions of the furnace and the associated safety requirements. A structural prototype was developed, which provided insights into the real-world operations of the design. The design verification process was exhaustive and thorough, conforming to the specifications detailed in the Specifications Table. Various tests were conducted to evaluate the functionality and safety of the system, including a dry run test, sensor test, and code testing.
The project matters as it enhances the educational experience for students in the microfabrication lab, providing a user-friendly control over the furnace system. It also improves the lab\u27s image, making it more appealing to prospective students. The project\u27s success demonstrates the effectiveness of a comprehensive design and implementation process in achieving safety and reliability in a complex engineering system
Social Factors Affecting Treatment of Cervical Cancer: Ethical Issues and Policy Implications
Health care in the United States has become a privilege rather than a right. Patients who have the greatest need are the ones most likely to be denied this privilege. Despite recent advances in disease detection and treatment, many patients do not receive even the bare minimum of care. The high complexity of the health care system in the setting of patients with low levels of health literacy significantly affects the ability to seek and receive treatment in a timely fashion. In addition, lack of insurance, transportation, and social support further complicate access to care. To truly provide a standard of care to all patients, regardless of resources, our health care system must evolve to address the needs of the population. In this paper, we report a tragic case where social factors affected the outcome of a single mother with advanced cervical cancer
Beryllium and Alpha-Element Abundances in a Large Sample of Metal-Poor Stars
The light elements, Li, Be, and B, provide tracers for many aspects of
astronomy including stellar structure, Galactic evolution, and cosmology. We
have taken spectra of Be in 117 metal-poor stars ranging in metallicity from
[Fe/H] = -0.5 to -3.5 with Keck I + HIRES at a resolution of 42,000 and
signal-to-noise ratios of near 100. We have determined the stellar parameters
spectroscopically from lines of Fe I, Fe II, Ti I and Ti II. The abundances of
Be and O were derived by spectrum synthesis techniques, while abundances of Fe,
Ti, and Mg were found from many spectral line measurements. There is a linear
relationship between [Fe/H] and A(Be) with a slope of +0.88 +-0.03 over three
orders of magnitude in [Fe/H]. We fit the relationship between A(Be) and [O/H]
with both a single slope and with two slopes. The relationship between [Fe/H]
and [O/H] seems robustly linear and we conclude that the slope change in Be vs.
O is due to the Be abundance. Although Be is a by-product of CNO, we have used
Ti and Mg abundances as alpha-element surrogates for O in part because O
abundances are rather sensitive to both stellar temperature and surface
gravity. We find that A(Be) tracks [Ti/H] very well with a slope of 1.00
+-0.04. It also tracks [Mg/H] very well with a slope of 0.88 +-0.03. We find
that there are distinct differences in the relationships of A(Be) and [Fe/H]
and of A(Be) and [O/H] for our dissipative stars and our accretive stars. We
suggest that the Be in the dissipative stars was primarily formed by GCR
spallation and Be in the accretive stars was formed in the vicinity of SN II.Comment: Accepted for Ap.J. Nov. 10, 2011, v. 741 70 pages, 27 figures, 5
table
- âŠ