Activation mechanisms in sodium-doped Silicon MOSFETs

We have studied the temperature dependence of the conductivity of a silicon MOSFET containing sodium ions in the oxide above 20 K. We find the impurity band resulting from the presence of charges at the silicon-oxide interface is split into a lower and an upper band. We have observed activation of electrons from the upper band to the conduction band edge as well as from the lower to the upper band. A possible explanation implying the presence of Hubbard bands is given.Comment: published in J. Phys. : Condens. Matte

Consistency of dust solutions with div H=0

One of the necessary covariant conditions for gravitational radiation is the vanishing of the divergence of the magnetic Weyl tensor H_{ab}, while H_{ab} itself is nonzero. We complete a recent analysis by showing that in irrotational dust spacetimes, the condition div H=0 evolves consistently in the exact nonlinear theory.Comment: 3 pages Revte

Disorder and electron interaction control in low-doped silicon metal-oxide-semiconductor field effect transistors

We fabricated silicon metal-oxide-semiconductor field effect transistors where an additional sodium-doped layer was incorporated into the oxide to create potential fluctuations at the Si-SiO2 interface. The amplitude of these fluctuations is controlled by both the density of ions in the oxide and their position relative to the Si-SiO2 interface. Owing to the high mobility of the ions at room temperature, it is possible to move them with the application of a suitable electric field. We show that, in this configuration, such a device can be used to control both the disorder and the electron-electron interaction strength at the Si-SiO2 interface.Comment: 3 pages, 2 figure

Differences in Academic Performance by School District Size for Students in Special Education: A Multiyear, Statewide Investigation

In this empirical statewide multiyear analysis the extent to which the academic performance of students enrolled in special education was influenced by school district student enrollment was determined Five years of Texas statewide data on the Texas Assessment Knowledge Skills Reading Mathematics Science Social Studies and Writing exams were analyzed as a function of three school district sizes a small-size up to 1 599 students b moderate-size 1 600 to 9 999 students and c large-size 10 000 or more students Inferential statistical procedures revealed that students in special education who were enrolled in large-size school districts had statistically significantly higher passing rates on all five exams than did students in special education who were enrolled in either moderate-size or small-size school districts for all 5 years Effect sizes were smal

Combinations of isoform-targeted histone deacetylase inhibitors and bryostatin analogues display remarkable potency to activate latent HIV without global T-cell activation

AbstractCurrent antiretroviral therapy (ART) for HIV/AIDS slows disease progression by reducing viral loads and increasing CD4 counts. Yet ART is not curative due to the persistence of CD4+ T-cell proviral reservoirs that chronically resupply active virus. Elimination of these reservoirs through the administration of synergistic combinations of latency reversing agents (LRAs), such as histone deacetylase (HDAC) inhibitors and protein kinase C (PKC) modulators, provides a promising strategy to reduce if not eradicate the viral reservoir. Here, we demonstrate that largazole and its analogues are isoform-targeted histone deacetylase inhibitors and potent LRAs. Significantly, these isoform-targeted HDAC inhibitors synergize with PKC modulators, namely bryostatin-1 analogues (bryologs). Implementation of this unprecedented LRA combination induces HIV-1 reactivation to unparalleled levels and avoids global T-cell activation within resting CD4+ T-cells.</jats:p

Graduation Rate Differences by Ethnicity/Race at Texas Community Colleges: A Statewide, Multiyear Examination

In this multiyear, statewide investigation, the degree to which differences were present in graduation rates between Black and White, Black and Hispanic, and Black and Asian students was addressed for the 2007-2008 academic year to the 2015-2016 academic years. Inferential statistical procedures revealed the presence of statistically significant differences for all 9 academic years. In all 9 years, Black students had statistically significantly lower graduation rates than White, Hispanic, and Asian students. Also identified were the Texas community colleges that had the highest and that had the lowest graduation rates of their Black students in the last two academic years. Implications of these findings and recommendations for future research were discussed

Differences in the 1-Year Persistence Rates of International Students by Their Institutional Status at Texas Community Colleges: A Statewide, Multiyear Investigation

In this multiyear, statewide study, the degree to which 1-year persistence rates differed by the institutional status (i.e., stayed or transferred) of International students who were enrolled in Texas community colleges was determined.&nbsp; Inferential statistical procedures revealed the presence of statistically significant differences in 1-year persistence rates between International students who stayed at the same Texas community college and International students who transferred to a different Texas community college.&nbsp; In all cases, the 1-year persistence rates of International students who stayed were higher, 14 to 52 times higher, than the 1-year persistence rate of International students who transferred.&nbsp; In all 15 academic years (i.e., 1999-2000 through 2013-2014), very large effect sizes were present. &nbsp

Gender Differences in Postsecondary Enrollment Rates of Texas Public High School

Examined in this study was the degree to which gender differences were present in the postsecondary enrollment of Texas public high school graduates at Texas 2-year public colleges and at 4-year public universities.&nbsp; Specifically analyzed were the enrollment percentages of males and females for three academic years (i.e., 2012-2013 through 2014-2015) for Texas public high school graduates.&nbsp; Over the 3-year time period analyzed, statistically significant differences were present in the postsecondary enrollment of Texas public high school graduates by gender.&nbsp; Female Texas public high school graduates enrolled in both 2-year and 4-year public institutions at a higher rate than their male counterparts.&nbsp; Moreover, females tended to enroll at 2-year institutions at a higher rate then 4-year institutions.&nbsp; Implications of these results and recommendations for future research were discussed

Evidence for multiple impurity bands in sodium-doped silicon MOSFETs

We report measurements of the temperature-dependent conductivity in a silicon metal-oxide-semiconductor field-effect transistor that contains sodium impurities in the oxide layer. We explain the variation of conductivity in terms of Coulomb interactions that are partially screened by the proximity of the metal gate. The study of the conductivity exponential prefactor and the localization length as a function of gate voltage have allowed us to determine the electronic density of states and has provided arguments for the presence of two distinct bands and a soft gap at low temperature.Comment: 4 pages; 5 figures; Published in PRB Rapid-Communication

Spherical harmonic based noise rejection and neuronal sampling with multi-axis OPMs

In this study we explore the interference rejection and spatial sampling properties of multi-axis Optically Pumped Magnetometer (OPM) data. We use both vector spherical harmonics and eigenspectra to quantify how well an array can separate neuronal signal from environmental interference while adequately sampling the entire cortex. We found that triaxial OPMs have superb noise rejection properties allowing for very high orders of interference (L=6) to be accounted for while minimally affecting the neural space (2dB attenuation for a 60-sensor triaxial system). We show that at least 11th order (143 spatial degrees of freedom) irregular solid harmonics or 95 eigenvectors of the lead field are needed to model the neural space for OPM data (regardless of number of axes measured). This can be adequately sampled with 75-100 equidistant triaxial sensors (225-300 channels) or 200 equidistant radial channels. In other words, ordering the same number of channels in triaxial (rather than purely radial) configuration may give significant advantages not only in terms of external noise rejection but also by minimizing cost, weight and cross-talk