Assessment of K-12 educators’ awareness and need for online self-publishing services in the classroom

This thesis surveyed K-12 educators to gauge their comfort level and awareness with online self-publishing services along with required skill sets, testing whether K-12 educators are taking advantage of online self-publishing within the classroom. If educators were to adopt online self-publishing to create material for the students, there is a potential new market for the Print-On-Demand industry. The experimental design involved the creation of an online survey taken by K-12 educators across the United States. The survey was used to gauge respondent comfort level with online self-publishing skills for personal and school use. Their opinions on collaboration with other educators to produce material for the students benefit were also addressed. The main findings of this research were that, 15% of respondents have had personal online self-publishing experience, 61% were aware of popular online self-publishing websites, and editing was viewed as the most helpful skill to have when producing self-published book online. With school use, 44% of respondents reported their school had a student publishing assignment with yearbooks being the most commonly published item in schools. Teacher use in the classroom revealed that 58% of respondents were interested in using self-publishing, 54% of respondents had already produced material for the students benefit. Moreover 90% believed that providing the students with a more targeted and customized learning experience was a main benefit of self-publishing. However, respondents did not understand how online self-publishing could save costs in textbook orders. If educators better understood there is a potential cost savings, it would generate a greater interest in pursuing some form of online self-publishing

Density distribution of particles upon jamming after an avalanche in a 2D silo

We present a complete analysis of the density distribution of particles in a two dimensional silo after discharge. Simulations through a pseudo-dynamic algorithm are performed for filling and subsequent discharge of a plane silo. Particles are monosized hard disks deposited in the container and subjected to a tapping process for compaction. Then, a hole of a given size is open at the bottom of the silo and the discharge is triggered. After a clogging at the opening is produced, and equilibrium is restored, the final distribution of the remaining particles at the silo is analyzed by dividing the space into cells with different geometrical arrangements to visualize the way in which the density depression near the opening is propagated throughout the system. The different behavior as a function of the compaction degree is discussed.Comment: 11 pages, 10 figure

Mitosene-DNA adducts. Characterization of two major DNA monoadducts formed by 1,10-bis(acetoxy)-7-methoxymitosene upon reductive activation

Reductive activation of racemic 1,10-bis(acetoxy)-7-methoxymitosene WV15 in the presence of DNA, followed by enzymatic digestion and HPLC analysis, revealed the formation of various DNA adducts. Reduction is a necessary event for adduct formation to occur. This reductive activation was performed under hypoxic conditions in various ways:  (1) chemically, using a 2-fold excess of sodium dithionite (Na2S2O4), (2) enzymatically using NADH-cytochrome c reductase, (3) electrochemically on a mercury pool working electrode, and (4) catalytically, using a H2/PtO2 system. Five different mitosene−DNA adducts were detected. These adducts were also present when poly(dG-dC) was used instead of DNA, but were absent with poly(dA-dT). All were shown to be adducts of guanine. Reduction of 1,10-dihydroxymitosene WV14 in the presence of DNA did not result in detectable adduct formation, demonstrating the importance of good leaving groups for efficient adduct formation by these mitosenes. Finally, two of the adducts were isolated and their structures elucidated, using mass spectrometry, 1H NMR and circular dichroism (CD). The structures were assigned as the diastereoisomers N2-(1‘ ‘-n-hydroxymitosen-10‘ ‘-yl), 2‘-deoxyguanosine (n = α or β). These type of adducts, in which the mitosene C-10 is covalently bonded to the N-2 of a guanosylic group, are different from the well-known mitomycin C 2‘-deoxyguanosine monoadducts, that is linked via the mitomycin C C-1 position, demonstrating that the order of reactivity of the C-1 and C-10 in these mitosenes is reversed, as compared to mitomycin C. The 7-methoxy substituent of WV15 is a likely factor causing this switch. Evidence is presented that the 7-substituent of mitosenes also influences their DNA alkylation site. Adducts 4 and 5 represent the first isolated and structurally characterized covalent adducts of DNA and a synthetic mitosene

The space density of z>4 blazars

High redshift blazars are an important class of Active Galactic Nuclei (AGN) that can provide an independent estimate of the supermassive black-hole mass function in high redshift radio-loud AGN without the bias due to absorption along the line-of-sight. Using the Cosmic Lens All Sky Survey (CLASS) we built a complete radio flux-limited sample of high redshift (z>4) blazars suitable for statistical studies. By combining dedicated optical observations and the SDSS spectroscopic database, we obtained a sample of 26 blazar candidates with a spectroscopic redshift above 4. On the basis of their radio spectrum we distinguish between blazars and QSO with a Gigahertz Peaked Spectrum (GPS) like spectrum. Out of the 18 confirmed blazars 14 constitute a completely identified, flux-limited sample down to a magnitude of 21 (AB). Using this complete sample we derive a space density of blazars with 4<z<5.5 of rho=0.13 (+0.05,-0.03) Gpc^-3. This is the first actual estimate of the blazar space density in this range of redshift. This value is in good agreement with the extrapolation of the luminosity function and cosmological evolution based on a sample of flat-spectrum radio quasars selected at lower redshifts and it is consistent with a cosmological evolution peaking at z$\sim$2 similar to radio-quiet QSO. We do not confirm, instead, the presence of a peak at z~4 in the space density evolution, recently suggested using an X-ray selected sample of blazars. It is possible that this extreme peak of the evolution is present only among the most luminous blazars.Comment: 14 pages, accepted for publication on MNRAS (https://doi.org/10.1093/mnras/sty3526

A standalone bioreactor system to deliver compressive load under perfusion flow to hBMSC-seeded 3D chitosan-graphene templates

The availability of engineered biological tissues holds great potential for both clinical applications and basic research in a life science laboratory. A prototype standalone perfusion/compression bioreactor system was proposed to address the osteogenic commitment of stem cells seeded onboard of 3D chitosan-graphene (CHT/G) templates. Testing involved the coordinated administration of a 1 mL/min medium flow rate together with dynamic compression (1% strain at 1 Hz; applied twice daily for 30 min) for one week. When compared to traditional static culture conditions, the application of perfusion and compression stimuli to human bone marrow stem cells using the 3D CHT/G template scaffold induced a sizable effect. After using the dynamic culture protocol, there was evidence of a larger number of viable cells within the inner core of the scaffold and of enhanced extracellular matrix mineralization. These observations show that our novel device would be suitable for addressing and investigating the osteogenic phenotype commitment of stem cells, for both potential clinical applications and basic research

Nonlinear Trimodal Regression Analysis of Radiodensitometric Distributions to Quantify Sarcopenic and Sequelae Muscle Degeneration.

Efst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked Files.Muscle degeneration has been consistently identified as an independent risk factor for high mortality in both aging populations and individuals suffering from neuromuscular pathology or injury. While there is much extant literature on its quantification and correlation to comorbidities, a quantitative gold standard for analyses in this regard remains undefined. Herein, we hypothesize that rigorously quantifying entire radiodensitometric distributions elicits more muscle quality information than average values reported in extant methods. This study reports the development and utility of a nonlinear trimodal regression analysis method utilized on radiodensitometric distributions of upper leg muscles from CT scans of a healthy young adult, a healthy elderly subject, and a spinal cord injury patient. The method was then employed with a THA cohort to assess pre- and postsurgical differences in their healthy and operative legs. Results from the initial representative models elicited high degrees of correlation to HU distributions, and regression parameters highlighted physiologically evident differences between subjects. Furthermore, results from the THA cohort echoed physiological justification and indicated significant improvements in muscle quality in both legs following surgery. Altogether, these results highlight the utility of novel parameters from entire HU distributions that could provide insight into the optimal quantification of muscle degeneration.European Commissio