284 research outputs found
Classic connections turning teens on to great literature
No full textGetting teens to read, much less enjoy classic literary fiction is an on-going challenge for educators and librarians. However, Holly Koelling--author, YA librarian, and "booktalker extraordinaire"-offers a variety of techniques for rising to that challenge and successfully selecting, presenting, and connecting teens with great literature in the library and in school. This book defines "classics" and discusses why they are important, then provides a step-by-step process for finding the "hooks" that attract teens, educating yourself about classic literature, and motivating and inspiring readers. This is an upbeat, information-packed guide that anyone working with teen readers will refer to again and again. Learn how to attract, motivate, and inspire teens to read and appreciate great classic literature. A practical guide, packed with ideas, techniques, and booklists
Migratory chondrogenic progenitor cells from late stages of osteoarthritis exhibit gender differences.
No full textLinking oxygen and carbon uptake with the Meridional Overturning Circulation using a transport mooring array
No full text© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Atamanchuk, D., Palter, J., Palevsky, H., Le Bras, I., Koelling, J., & Nicholson, D. Linking oxygen and carbon uptake with the Meridional Overturning Circulation using a transport mooring array. Oceanography, 34(4), (2021): 9, https://doi.org/10.5670/oceanog.2021.supplement.02-03.The Atlantic Meridional Overturning Circulation (AMOC) is a system of ocean currents that transports warm, salty water poleward from the tropics to the North Atlantic. Its structure and strength are monitored at several latitudes by mooring arrays installed by the international ocean sciences community. While the main motivation for deploying these mooring arrays is to understand the AMOC’s influence on Northern Hemisphere climate, the circulation system also plays a crucial role in distributing oxygen (O2) and carbon dioxide (CO2) throughout the global ocean. By adding O2 sensors to several of the moorings at 53°N–60°N (Figure 1) in the western Labrador Sea, Koelling et al. (2021) demonstrated that the formation of deep water, in which the AMOC brings surface water to the deep ocean, is important for supplying the oxygen consumed by deep-ocean ecosystems throughout the North Atlantic. Additionally, variability in the deep-water formation has been linked to changes in the amount of anthropogenic CO2 stored in the subpolar ocean (Raimondi et al., 2021). These studies, using data collected during research cruises and a small number of moored sensors, showed that deep-water formation and the AMOC are key to oxygen and carbon cycles in the North Atlantic. However, the common assumption that the magnitude and variability of O2 and CO2 uptake by the ocean are tied to the dynamics of the AMOC has never been evaluated on the basis of direct observations
STOIC
No full textStoic is a non-fiction childhood trauma memoir. The theme of loss is explored through the manuscript as the author delves into the family dynamics prior to a devastating car accident and the stark realities afterward. The mother is left a paraplegic as a result of the accident. The story takes place in the 1960s and early 1970s. This is one family's tragedy as told from a child's point-of-view. Set in a post-WWII suburban community, the comparison of relative prosperity and the loss of normalcy are detailed. The author incorporates both her Norwegian and German heritage as the family struggles to cope with an invalid mother. Issues of faith are interwoven throughout the text. Stoic is the story of a loving father and his four children as they care for a paraplegic.</p
Migratory chondrogenic progenitor cells from repair tissue during the later stages of human osteoarthritis.
No full textSummaryThe regeneration of diseased hyaline cartilage continues to be a great challenge, mainly because degeneration—caused either by major injury or by age-related processes—can overextend the tissue's self-renewal capacity. We show that repair tissue from human articular cartilage during the late stages of osteoarthritis harbors a unique progenitor cell population, termed chondrogenic progenitor cells (CPCs). These exhibit stem cell characteristics such as clonogenicity, multipotency, and migratory activity. The isolated CPCs, which exhibit a high chondrogenic potential, were shown to populate diseased tissue ex vivo. Moreover, downregulation of the osteogenic transcription factor runx-2 enhanced the expression of the chondrogenic transcription factor sox-9. This, in turn, increased the matrix synthesis potential of the CPCs without altering their migratory capacity. Our results offer new insights into the biology of progenitor cells in the context of diseased cartilage tissue. Our work may be relevant in the development of novel therapeutics for the later stages of osteoarthritis
Evaluation of Enzymatic Breakers for the Reduction of Environmental and Health Hazards Associated with Hydraulic Fracturing Fluids
No full textEngineering: 2nd Place (The Ohio State University Denman Undergraduate Research Forum)Hydraulic fracturing ("fracking") is the process in which highly-pressurized fluids are injected underground to obtain energy resources that could not otherwise be accessed. Under high pressures, fissures are created in rock formations, which free trapped energy resources. The fluids used are composed mostly of water with chemical additives, which each add a specific functionality. A polymer increases fluid viscosity to initiate the fracture. A crosslinker may be added to further increase viscosity. Breakers decrease fluid viscosity for flowback. Despite its ability to retrieve critical energy resources, a primary concern with fracturing is its impact to human health and the environment. Many fluid components are toxic and there is fear that the fluid may contaminate groundwater. The goal of the research was to identify alternative components for fracturing fluids. Specifically, breakers were examined. Current breakers are strong oxidizers which degrade the polymer by a free-radical mechanism at high temperatures. Enzymatic breakers, however, are benign to environmental and human health. Two cellulasic enzymes, β-mannanase and α-galactosidase, were proposed as alternative breakers and their performance was compared to that of ammonium persulfate, the industry-standard breaker. Polymer (0.5% wt. guar) and crosslinked polymer (0.5% wt. guar, 0.25% wt. sodium tetraborate) fluids were broken at well conditions (50oC) and industry-standard concentrations (ammonium persulfate: 0.01-0.1 wt. %; enzymes: 0.01-0.1 U/mL) over time (18 hr.). Rheological testing of these fluids included frequency sweeps (0.1-100 rads/s) and steady shear rate sweeps (0.1-100 1/s) to determine viscosity change over time and breaker kinetics. Filter cake testing was performed to study polymer degradation over time, as the breaker liberated low molecular weight oligomers. Enzymes show promise in competing with ammonium persulfate as a breaker, although further testing is necessary. More environmentally-friendly components for fracking fluids may allow hydraulic fracturing, important to the US energy portfolio, to continue with substantially-decreased risk.A one-year embargo was granted for this item.Academic Major: Chemical Engineerin
Hoehere Standzeiten beim Schaftfraesen durch Optimierung des Anschnittes
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Characterizing the perceived quality degradation of still-camera motion blur
No full textCamera motion blur was examined in two experiments, in an attempt to behaviorally validate candidate predictors of the associated degradation in photographic image quality.
In the first experiment, motion of a hand-held 35-mm single-lens-reflex camera was measured using inertial sensors while film was simultaneously exposed. Thirty-two subjects photographed two studio scenes at 1/60-s, 1/30-s, 1/15-s, and 1/8-s shutter speeds, replicated four times. Several spatial image quality metrics (blur size, Subjective Quality Factor, SQF; Modulation Transfer Function ,Area, MTFA; and Equivalent Passband, Ne), derived analytically from the motion data, were used as dependent measures for statistical analysis.
All three modulation-transfer-function (MTF)-based analytic quality metrics were strongly intercorrelated. Under these measures, the 1/60-s shutter speed yielded significantly higher quality photographs than the other speeds. The 1/8-s condition proved the worst. A difference between the 1/30-s and 1/15-s conditions was not reliably supported under the MTF-based metrics, although a significantly greater blur size resulted on average in the longer exposure. Tripod-mounted exposures compared favorably with the hand-held shots at 1/15 s and 1/8 s, but differences were not statistically supported at the two faster speeds.
In the second experiment, 16 prints of each scene were selected from those collected in the first experiment. The log-transformed analytic SQF values were used to select the prints, ranging from worst to best at equal increments. Measures of perceived image quality and sharpness were derived from psychophysical judgments by 48 observers.
Linear regression analyses identified several analytic models that predicted substantial amounts of the variance in mean judgments across all observers. The analytic SQF, MTFA, and Ne metrics based on the products of the unidimensional values in x and y each accounted for roughly 90% of the variance in relative judgments. The use of any of these measures is recommended for the evaluation of motion blur in future camera-shake studies. As a secondary choice, for computational ease, the blur size can be used.Ph. D
Composition analysis and transition energies of ultrathin Sn-rich GeSn quantum wells
No full textWhile GeSn alloys with high Sn content constitute direct group-IV semiconductors, their growth on Si remains challenging. The deposition of a few monolayers of pure Sn on Ge and their overgrowth with Ge using molecular beam epitaxy can be a means of obtaining Sn-rich quantum wells with very high Sn content while maintaining high crystal quality. Here, we provide structural and compositional information on such structures with very high accuracy. Based on our characterization results we theoretically predict transition energies and compare them with experimental results from photoluminescence measurements. Our results constitute the groundwork for tuning the molecular beam epitaxy based growth of Sn-rich quantum wells and dots for applications in electronic and optoelectronic devices
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