Inside Online Charter Schools

Online charter schools -- also known as virtual charters or cyber charters -- are publicly funded schools of choice that deliver student instruction via telecommunications. Today, about 200 online charter schools are operating in the United States, serving about 200,000 students at the elementary, middle, and high school grade levels. Although online instruction is increasing rapidly, there have been few studies of their operations and effects. In innovative new research funded by the Walton Family Foundation, the National Study of Online Charter Schools offers a rigorous analysis of online charter schools and their effects. Mathematica Policy Research's report provides the first nationwide data and analysis of the operations and instructional approaches of online charter schools, based on data collected in a survey completed by 127 principals of online charter schools across the country and public data from the U.S. Department of Education

The Immediate Effects of Carbon Composite Ankle Foot Orthoses on Balance and Gait in Individuals with Peripheral Neuropathy: A Pilot Study

Peripheral neuropathy (PN) is a neurological disorder that involves damage or disease of the peripheral nervous system. Diabetes is one of the most common causes on PN, while another large percentage of cases are idiopathic in nature. Individuals with PN often experience a distal to proximal progression of motor and sensory deficits such as loss of proprioception, muscle weakness, and loss of ankle reflexes. Since lower extremity proprioception plays a primary role in postural control, individuals with PN demonstrate difficulty maintaining balance, especially under conditions in which vision or vestibular input are also compromised. Because of these deficits, individuals with PN demonstrate an increased risk of falling. To improve balance in these individuals, literature suggests that providing additional or alternative sensory cues may enhance postural control. One practical strategy for improving sensory input that has been investigated is the use of orthotics or ankle-foot orthoses (AFO) to augment tactile and proprioceptive input to the foot and lower leg. Significant improvements in both sensory organization and postural motor control have been shown to occur with some commonly used AFOs, however, relatively little is known about how the newer generation carbon composite AFO may positively or negatively influence individuals with PN.https://ecommons.udayton.edu/dpt_symposium/1012/thumbnail.jp

On the Origin and Evolution of Life in the Galaxy

A simple stochastic model for evolution, based upon the need to pass a sequence of n critical steps (Carter 1983, Watson 2008) is applied to both terrestrial and extraterrestrial origins of life. In the former case, the time at which humans have emerged during the habitable period of the Earth suggests a value of n = 4. Progressively adding earlier evolutionary transitions (Maynard Smith and Szathmary, 1995) gives an optimum fit when n = 5, implying either that their initial transitions are not critical or that habitability began around 6 Ga ago. The origin of life on Mars or elsewhere within the Solar System is excluded by the latter case and the simple anthropic argument is that extraterrestrial life is scarce in the Universe because it does not have time to evolve. Alternatively, the timescale can be extended if the migration of basic progenotic material to Earth is possible. If extra transitions are included in the model to allow for Earth migration, then the start of habitability needs to be even earlier than 6 Ga ago. Our present understanding of Galactic habitability and dynamics does not exclude this possibility. We conclude that Galactic punctuated equilibrium (Cirkovic et al. 2009), proposed as a way round the anthropic problem, is not the only way of making life more common in the Galaxy.Comment: See http://www.astrobiologysociety.org/index.ph

Ehrlichia and Spotted Fever Group Rickettsiae Surveillance in Amblyomma americanum in Virginia Through Use of a Novel Six-Plex Real-Time PCR Assay

The population of the lone star tick Amblyomma americanum has expanded in North America over the last several decades. It is known to be an aggressive and nondiscriminatory biter and is by far the most common human-biting tick encountered in Virginia. Few studies of human pathogen prevalence in ticks have been conducted in our state since the mid-twentieth century. We developed a six-plex real-time PCR assay to detect three Ehrlichia species (E. chaffeensis, E. ewingii, and Panola Mountain Ehrlichia) and three spotted fever group Rickettsiae (SFGR; R. amblyommii, R. parkeri, and R. rickettsii) and used it to test A. americanum from around the state. Our studies revealed a presence of all three Ehrlichia species (0–24.5%) and a high prevalence (50–80%) of R. amblyommii, a presumptively nonpathogenic SFGR, in all regions surveyed. R. parkeri, previously only detected in Virginia’s Amblyomma maculatum ticks, was found in A. americanum in several surveyed areas within two regions having established A. maculatum populations. R. rickettsii was not found in any sample tested. Our study provides the first state-wide screening of A. americanum ticks in recent history and indicates that human exposure to R. amblyommii and to Ehrlichiae may be common. The high prevalence of R. amblyommii, serological cross-reactivity of all SFGR members, and the apparent rarity of R. rickettsii in human biting ticks across the eastern United States suggest that clinical cases of tick-borne disease, including ehrlichiosis, may be commonly misdiagnosed as Rocky Mountain spotted fever, and that suspicion of other SFGR as well as Ehrlichia should be increased. These data may be of relevance to other regions where A. americanum is prevalent

Benchmarking thiolate driven photoswitching of cyanine dyes

Carbocyanines are among the best performing dyes in single-molecule localization microscopy (SMLM), but their performance critically relies on optimized photoswitching buffers. Here, we study the versatile role of thiols in cyanine photoswitching at varying intensities generated in a single acquisition by a micro-electromechanical systems (MEMS) mirror placed in the excitation path. The key metrics we have analysed as a function of the thiolate concentration are photon budget, on-state and off-state lifetimes and the corresponding impact on image resolution. We show that thiolate acts as a concentration bandpass filter for the maximum achievable resolution and determine a minimum of ~1 mM is necessary to facilitate SMLM measurements. We also identify a concentration bandwidth of 1-16 mM in which the photoswitching performance can be balanced between high molecular brightness and high off-time to on-time ratios. Furthermore, we monitor the performance of the popular oxygen scavenger system based on glucose and glucose oxidase over time and show simple measures to avoid acidification during prolonged measurements. Finally, the impact of buffer settings is quantitatively tested on the distribution of the glucose transporter protein 4 within the plasma membrane of adipocytes. Our work provides a general strategy for achieving optimal resolution in SMLM with relevance for the development of novel buffers and dyes

Diagnosis of Partial Body Radiation Exposure in Mice Using Peripheral Blood Gene Expression Profiles

In the event of a terrorist-mediated attack in the United States using radiological or improvised nuclear weapons, it is expected that hundreds of thousands of people could be exposed to life-threatening levels of ionizing radiation. We have recently shown that genome-wide expression analysis of the peripheral blood (PB) can generate gene expression profiles that can predict radiation exposure and distinguish the dose level of exposure following total body irradiation (TBI). However, in the event a radiation-mass casualty scenario, many victims will have heterogeneous exposure due to partial shielding and it is unknown whether PB gene expression profiles would be useful in predicting the status of partially irradiated individuals. Here, we identified gene expression profiles in the PB that were characteristic of anterior hemibody-, posterior hemibody- and single limb-irradiation at 0.5 Gy, 2 Gy and 10 Gy in C57Bl6 mice. These PB signatures predicted the radiation status of partially irradiated mice with a high level of accuracy (range 79–100%) compared to non-irradiated mice. Interestingly, PB signatures of partial body irradiation were poorly predictive of radiation status by site of injury (range 16–43%), suggesting that the PB molecular response to partial body irradiation was anatomic site specific. Importantly, PB gene signatures generated from TBI-treated mice failed completely to predict the radiation status of partially irradiated animals or non-irradiated controls. These data demonstrate that partial body irradiation, even to a single limb, generates a characteristic PB signature of radiation injury and thus may necessitate the use of multiple signatures, both partial body and total body, to accurately assess the status of an individual exposed to radiation

Stability Testing of PtxSn1 − x/C Anodic Catalyst for Renewable Hydrogen Production Via Electrochemical Reforming of Ethanol

The stability testing of three different synthesized Pt x Sn1 − x /C anodic catalysts has been demonstrated for the renewable generation of hydrogen via the electrochemical reforming of ethanol in a proton exchange membrane (PEM) electrolysis cell. Three Pt-Sn anodic catalysts with different nominal Pt:Sn ratios of 60:40, 70:30, and 80:20 atomic (at.) % were synthetized and characterized by the means of electrochemical tests and XRD. Among them, the Pt-Sn anodic catalyst with 70:30 at. ratio showed the highest electrochemical active surface area (ECSA) and highest electrochemical reforming activity, which allowed the production of pure H2 with the lowest electrical energy requirement (below 23 kWh·kgH2 −1). The stability of the system was also demonstrated through a long-term chronopotentiometry experiment of 48 h in duration. The potential for practical use and coupling this technology with renewable solar energy, a number of cyclic voltammetry tests (with a low scan rate of 0.19 mV·s−1) were also carried out. These experiments were performed by simulating the electrical power produced by a photovoltaic cell. This test showed good stability/reproducibility of the MEA and, hence, a suitable integration between the two technologies for the sustainable energy storage in the form of hydrogen.La prueba de estabilidad de tres catalizadores anódicos de Pt x Sn 1 − x /C sintetizados diferentes se ha demostrado para la generación renovable de hidrógeno a través del reformado electroquímico de etanol en una celda de electrólisis de membrana de intercambio de protones (PEM). Tres catalizadores anódicos de Pt-Sn con diferentes relaciones nominales Pt:Sn de 60:40, 70:30 y 80:20 % atómico (at.) fueron sintetizados y caracterizados por medio de pruebas electroquímicas y XRD. Entre ellos, el catalizador anódico de Pt-Sn con 70:30 at. mostró la mayor superficie electroquímica activa (ECSA) y la mayor actividad de reformado electroquímico, lo que permitió la producción de H 2 puro con el menor requerimiento de energía eléctrica (por debajo de 23 kWh·kg H2 −1 ). La estabilidad del sistema también se demostró mediante un experimento de cronopotenciometría a largo plazo de 48 h de duración. El potencial de uso práctico y el acoplamiento de esta tecnología con la energía solar renovable, también se llevaron a cabo una serie de pruebas de voltamperometría cíclica (con una baja tasa de exploración de 0,19 mV·s- 1 ). Estos experimentos se realizaron simulando la energía eléctrica producida por una celda fotovoltaica. Esta prueba mostró una buena estabilidad/reproducibilidad del MEA y, por tanto, una adecuada integración entre las dos tecnologías para el almacenamiento de energía sostenible en forma de hidrógeno

Contexto bioético de la venta de misoprostol en las farmacias y boticas del Perú

La presente es una investigación bibliográfica y tuvo como objetivos describir, comprender y analizar el contexto bioético de la venta del misoprostol en las farmacias y boticas del Perú. Se analizó la documentación científica así como oficial de instituciones públicas y privadas, nacionales e internacionales, como los riesgos para la salud y vida de la mujer del uso del misoprostol de manera clandestina, la vigencia de este medicamento en las terapias como protector de la mucosa gástrica, su venta en las farmacias y boticas de manera oficial y clandestina. Los resultados indicaron que sí existen por la venta del misoprostol al público transgresiones contra principios bioéticos y regulatorios que ponen en riesgo la vida y la salud de la mujer y del concebido. Las conclusiones proponen alternativas a los problemas bioéticos que plantea este medicamento en su venta en farmacias y boticas del Perú.Tesi

Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy

The alteration of intra-ligand donor-acceptor interactions through torsional connectivity in substituted Re-dppz complexes

The ground and excited properties of a series of [ReCl(CO)3(dppz)] complexes with substituted donor groups have been investigated. Alteration of donor-acceptor communication through modulation of torsional angle and the number and nature of the donor substituent allowed the effects on the photophysical properties to be characterized though both computational and spectroscopic techniques, including TD-DFT, resonance Raman and time resolved infrared. The ground state optical properties show significant variation as a result of donor group modulation, with increased angle between the donor and acceptor blue-shifting and depleting the intensity of the lowest energy transition, which was consistently ILCT in nature. However, across all complexes studied there was minimal perturbation to the excited state properties and dynamics. Three excited states on the picosecond, nanosecond and microsecond time scales were observed in all cases, corresponding to 1ILCT, ππ* and 3ILCT respectively