Four-Day Modified School Systems in Rural Oklahoma

Over the past 40 years, school districts in rural areas have been forced to move to a modified four-day school schedule. As of 2019, 650 schools in over 25 states operate on a four-day modified school model. The purpose of this qualitative case study was to explore teachers’ and administrators’ perceptions of the four-day school week. Four research questions guided the study: (a) How do teachers and administrators perceive the four-day school system in Oklahoma?, (b) Why do teachers and administrators support or not support a four-day school system in Oklahoma?, (c) How do teachers and administrators perceive the impact of the four- day school system on students’ academic performance?, and (d) What suggestions do teachers and administrators have for districts considering the implementation of the four-day school week? The participants were 15 teachers and five administrators from rural school districts in Oklahoma. Interviews and a focus group discussion were adopted as instruments for the study. Data were collected through Zoom and analyzed manually. The findings showed seven significant emergent themes. The significant themes for interviews were (a) increased teacher and student attendance, (b) increased student morale and decreased discipline issues, (c) increased teacher morale and retention, and (d) more time for family and personal business. The significant themes for the focus group discussion consisted of (a) increased teacher and student attendance, (b) increased student morale and decreased discipline issues, and (c) school finance benefits. Recommendations were included

Shock-compressed MgSiO_3 glass, enstatite, olivine, and quartz: Optical emission, temperatures, and melting

Optical emission of MgSiO_3 glass, enstatite, olivine, and quartz under shock wave compression was investigated with optical pyrometry at discrete wavelengths ranging from visible to near infrared. We develop a new analysis of optical emission that does not require a gray body assumption. Instead, at each wavelength, the optical linear absorption coefficients (α) and blackbody spectral radiances (L_(λb)) of shocked and unshocked materials were obtained by nonlinear fitting to the time-resolved radiance from the target assembly. The absorption spectra of unshocked samples corresponding to the measured values of α reproduce those from independent static optical spectroscopic measurements. The measured values of α (ranging from 7 to 56 mm^(−1)) for shocked samples indicate that shock-induced high-pressure phases (including melt) can be regarded essentially as black bodies in the optical range investigated, although starting phases such as enstatite and olivine have band-like spectra at ambient conditions. The effect of emission from the air gap at the driver sample interface on the recorded radiance can be resolved, but α and L_(λb) cannot be separated for this component of the signal. The shock velocity-particle velocity relationships of these silicates derived from radiance history are in accord with previous investigations using independent techniques. Given the limited amount of shock wave data, possible high-pressure melting curves of Mg-perovskite and its assemblage with periclase are deduced; their melting temperatures near the core-mantle boundary (CMB) being 6000 ± 500 K and 4000 ± 300 K, respectively. It is proposed that Mg-perovskite melts with density increase at the CMB pressure

Shock-induced melting of MgSiO_3 perovskite and implications for melts in Earth's lowermost mantle

New shock wave equation of state (EOS) data for enstatite and MgSiO_3 glass constrain the density change upon melting of Mg-silicate perovskite up to 200 GPa. The melt becomes denser than perovskite near the base of Earth's lower mantle. This inference is confirmed by shock temperature data suggesting a negative pressure-temperature slope along the melting curve at high pressure. Although melting of Earth's mantle involves multiple phases and chemical components, this implies that the partial melts invoked to explain anomalous seismic velocities in the lowermost mantle may be dynamically stable

Teaching Literacy: A Puzzle-Based Approach

In an effort to achieve stronger, curricular alignment and establish a more concrete relationship between literacy theory and instructional practice, curricular redesign within an undergraduate, literacy methods course commenced. With a clear rationale for why course redesign was necessary, a collective vision rooted with intention and focused on student learning drove the redesign process. After much thought and critical reflection, instructional planning was complete and the Model of the Complete, Literate Student was born. This research-based model holistically identifies ten puzzle pieces critical to one’s literacy development and ultimately, became the framework that anchored all course content. Course redesign was successful and yielded many benefits including: a meaningful showcase of literacy instruction and assessment; improved scaffolding to better support student learning; intentional, instructional planning; richer learning experiences for students; and, opportunities for professional collaboration. While course redesign is complete, the appropriate next step would be to closely examine students’ perceptions of the redesigned course, as well as the effectiveness of the model to further support student learning

Superradiant lasing from J-aggregated molecules adsorbed onto colloidal silver

Cataloged from PDF version of article.The picosecond time-resolved emission spectrum of the cyanine dye 1,18-diethyl-3,38- bis-~3-sulfopropyl!-5,58,6,68-tetrachlorobenzimidazolocarbocyanine ~also known as BIC! adsorbed onto colloidal silver was examined as a function of laser pulse energy at room temperature. BIC is found to aggregate on colloidal silver, and the number of coherently responding molecules involved in the one-exciton state ~i.e., the coherence length! was estimated to involve 8–9 molecules. Lasing at a remarkably low incident pulse energy threshold was found for this system and explained in terms of a mechanism involving superradiant states created in coherently coupled adsorbed molecules that emit photons which stimulate emission from other spatially distributed superradiant states. © 1998 American Institute of Physics

The Wilson-Garnjobst heterokaryon incompatibility tester strains of Neurospora crassa contain modifiers which influence growth rate of heterokaryons and distort segregation ratios.

Recent interest and accelerated research into the genetics of heterokaryon incompatibility (HI) in Neurospora crassa has led to increased use of the original Wilson-Garnjobst HI tester strains available from FGSC (1994 Catalog of Strains, Part VII.D.1.). We have found inconsistencies and abnormalities in both growth of heterokaryons and segregation of markers in crosses using these strains. First noticed was a lack of vigor and incomplete complementation of markers in forced heterokaryons when compared to compatible heterokaryons with known Oak Ridge (OR) background. Secondly, skewed allele ratios were recorded in crosses between the Wilson-Garnjobst strains and strains with OR background. Perkins and Bjorkman raised a cautionary note about these strains (1978 Neurospora Newsl. 25:24-25), however, they concentrated primarily on the scot mutant present in these and other strains originating from the Rockefeller-Lindegren (RL) background. We have attempted to further characterize the erratic behavior of Wilson-Garnjobst strains and determine if the scot mutant or other modifiers of HI are responsible

Relationships Between Indices of Macrovascular and Microvascular Function in Young, Black Women

Blacks (BL) exhibit an exaggerated prevalence of and mortality from cardiovascular disease (CVD) relative to other populations. Macro- and microvascular dysfunction is often a hallmark of heightened CVD risk, with both demonstrated in BL. However, data regarding this dysfunction remains sparse, particularly in BL women. Common indices of vascular function include flow-mediated dilation (FMD) and reactive hyperemia (RH) following a brief period of suprasystolic cuff occlusion and cutaneous thermal reactivity to local heating (LH). However, the relationship between these indices has not been established in BL women. PURPOSE: The present study aimed to test the relationship between indices of vascular function in BL women as assessed by FMD, RH, and LH. METHODS: To test this hypothesis, 6 white women (WW) and 6 BW (age: 22±2 vs. 21±3, respectively) were studied. FMD and RH were assessed following a period of suprasystolic cuff occlusion. Briefly, a rapid inflation cuff was secured just distal to the antecubital fossa for arterial occlusion. Blood velocity (Vmean; cm ∙ s-1) and vessel diameter (d; mm) were measured continuously via high-resolution, duplex Doppler ultrasound during a 2-min baseline, 5-min of cuff occlusion, and 3-min of recovery. FMD was determined as the percent dilation from baseline (%FMD) while RH was determined as the peak and area under the curve (AUC) responses for shear rate (8 ∙ Vmean ∙ d-1) and blood flow (Vmean ∙ π ∙ (d ∙ 20-1)2 ∙ 60). Cutaneous thermal reactivity was assessed using laser-Doppler flowmetry during a standard LH protocol and reported as cutaneous vascular conductance (CVC; red blood cell flux/mean arterial pressure). Following a baseline with local skin temperature clamped at 33°C, a 39°C heat stimulus was applied to induce cutaneous vasodilation for ~30-min. The sustained vasodilation at the end of heating is predominantly nitric oxide mediated and provides an index of microvascular function. As the LH component served as part of a larger intradermal microdialysis protocol, maximal blood flow responses were elicited via combined intradermal sodium nitroprusside (28mM) infusion and 43°C heating. CVC during the 39°C plateau was normalized to maximal CVC (%CVCmax) to account for intersite variability. Pearson correlations were then performed between the FMD, RH, and LH responses. RESULTS: Significant relationships were observed between %FMD and shear AUC (r = 0.89; P = 0.02), and blood flow AUC (r = 0.92; P = 0.01) in WW, but not in BW (r = 0.63; P = 0.18 and r = -0.24; P = 0.65, respectively). However, neither FMD nor RH correlated with the cutaneous blood flow responses to LH (P \u3e 0.05) in either WW or BW. CONCLUSION: These preliminary data suggest that FMD is highly correlated to some indices of RH in WW, but that this relationship does not hold in BW. Further, there appears to be no relationship between microvascular function as assessed by RH and LH in either population

Ice-sheet bed 3-D tomography

This is the published version. Copyright 2010 International Glaciological SocietyInformation on bed topography and basal conditions is essential to developing the next-generation ice-sheet models needed to generate a more accurate estimate of ice-sheet contribution to sea-level rise. Synthetic aperture radar (SAR) images of the ice–bed can be analyzed to obtain information on bed topography and basal conditions. We developed a wideband SAR, which was used during July 2005 to perform measurements over a series of tracks between the GISP2 and GRIP cores near Summit Camp, Greenland. The wideband SAR included an eight-element receive-antenna array with multiple-phase centers. We applied the MUltiple SIgnal Classification (MUSIC) algorithm, which estimates direction of arrival signals, to single-pass multichannel data collected as part of this experiment to obtain fine-resolution bed topography. This information is used for producing fine-resolution estimates of bed topography over a large swath of 1600m, with a 25m posting and a relative accuracy of approximately 10m. The algorithm-derived estimate of ice thickness is within 10m of the GRIP ice-core length. Data collected on two parallel tracks separated by 500m and a perpendicular track are compared and found to have difference standard deviations of 9.1 and 10.3m for the parallel and perpendicular tracks, respectively

Passing the Torch: Continuation of the South Carolina Libraries Journal

In this article, The South Carolina Libraries Editorial Board discusses the history and rebuilding of the South Carolina Libraries journal, the official publication of the South Carolina Library Association (SCLA). As the journal adjusted in response to community needs, changes in the Editorial Board, the publication cycle, and peer review process were made to expand and enhance the functionality, appearance, and content of the journal. The Editorial Board reviews strategies for library community members – including practitioners, research faculty, and LIS students – to become involved as a part of the publication through authoring, book reviewing, peer reviewing, or artwork for future issues

Physiological and morphological properties of Dbx1-derived respiratory neurons in the pre-Botzinger complex of neonatal mice

Key points center dot The transcription factor Dbx1 gives rise to putatively respiratory rhythm-generating neurons in the pre-Botzinger complex. Comparative analysis of Dbx1-derived (Dbx1+) and non-Dbx1- derived (Dbx1) neurons can help elucidate the cellular bases of respiratory rhythm generation. center dot In vitro, Dbx1+ neurons activate earlier in the respiratory cycle, discharge larger magnitude inspiratory bursts and exhibit a lower rheobase compared with Dbx1 neurons. center dot The Dbx1+ neurons tend to express the intrinsic currents IA (transient outward A-current) and Ih (hyperpolarization-activated current) in diametric opposition, which may facilitate temporal summation of excitatory synaptic inputs, whereas the Dbx1 neurons show no significant pattern of expression regarding IA and Ih. center dot The Dbx1+ neurons exhibit smooth, spineless dendrites that project in the transverse plane, whereas the Dbx1 neurons are confined to the transverse plane to a lesser extent and sometimes exhibit spines. center dot The properties of Dbx1+ neurons that may contribute to respiratory rhythmogenesis include a high level of excitability linked to ongoing network activity and dendritic properties that may facilitate synaptic integration. Abstract Breathing in mammals depends on an inspiratory-related rhythm that is generated by glutamatergic neurons in the pre-Botzinger complex (preBotC) of the lower brainstem. A substantial subset of putative rhythm-generating preBotC neurons derive from a single genetic line that expresses the transcription factor Dbx1, but the cellular mechanisms of rhythmogenesis remain incompletely understood. To elucidate these mechanisms, we carried out a comparative analysis of Dbx1-expressing neurons (Dbx1+) and non-Dbx1-derived (Dbx1) neurons in the preBotC. Whole-cell recordings in rhythmically active newborn mouse slice preparations showed that Dbx1+ neurons activate earlier in the respiratory cycle and discharge greater magnitude inspiratory bursts compared with Dbx1 neurons. Furthermore, Dbx1+ neurons required less input current to discharge spikes (rheobase) in the context of network activity. The expression of intrinsic membrane properties indicative of A-current (IA) and hyperpolarization-activated current (Ih) tended to be mutually exclusive in Dbx1+ neurons. In contrast, there was no such relationship in the expression of currents IA and Ih in Dbx1 neurons. Confocal imaging and digital morphological reconstruction of recorded neurons revealed dendritic spines on Dbx1 neurons, but Dbx1+ neurons were spineless. The morphology of Dbx1+ neurons was largely confined to the transverse plane, whereas Dbx1 neurons projected dendrites to a greater extent in the parasagittal plane. The putative rhythmogenic nature of Dbx1+ neurons may be attributable, in part, to a higher level of intrinsic excitability in the context of network synaptic activity. Furthermore, Dbx1+ neuronal morphology may facilitate temporal summation and integration of local synaptic inputs from other Dbx1+ neurons, taking place largely in the dendrites, which could be important for initiating and maintaining bursts and synchronizing activity during the inspiratory phase