cssi/SciSciGPT-SciSciNet huggingface dataset:
Dynamic Phase Calibration Method for CSI-based Indoor Positioning

The demand for location-based services (LBS) increases significantly with the development of smart devices. Their built-in WiFi capability makes WiFi-based approaches essential for a range of indoor positioning applications. In such LBS systems, accessing received signal strength indicator (RSSI) and finer-grained channel state information (CSI) is enabled by modifying commodity WiFi devices. Additionally, multiple-input and multiple-output (MIMO) and orthogonal frequency-division multiplexing (OFDM) provide the spatial and frequency diversity to build the fingerprint database with CSI. However, due to hardware and environmental impacts, such systems suffer from phase errors and fingerprint noise. In this paper, a novel phase calibration method is proposed to reduce the fingerprint noise and improve the accuracy of CSI-based indoor positioning systems. The CSI phase of each subcarrier is extracted from the WiFi access points in a multi-antenna wireless network. First, the phase offset is calculated through the conventional method that uses a linear transformation to remove phase errors. Then, a dynamic phase calibration method is introduced to compensate for the phase offset by tracking the anomalous phase difference between each CSI sample and neighboring subcarrier. Finally, a machine learning algorithm is trained to estimate the target position. The performance of the proposed algorithm is investigated by evaluating the prediction rate from a margin of error (MoE) model and calculating the average distance error between the predicted grid and ground truth. Experimental results show the dynamic phase calibration method outperforms the conventional linear transformation calibration method by a higher prediction rate and improves the average position accuracy.
Ex Vivo MR Histology and Cytometric Feature Mapping Connect Three-dimensional in Vivo MR Images to Two-dimensional Histopathologic Images of Murine Sarcomas

A preclinical multiscale image registration platform facilitated reliable correlative studies of whole-slide cytometric feature maps and MR images to characterize how cytoarchitecture influences MR...
Race-Based Sexual Stereotypes, Gendered Racism, and Sexual Decision Making Among Young Black Cisgender Women:

Background. Due to their intersecting racial identity and gender identity, Black women are characterized by stigmatizing race-based sexual stereotypes (RBSS) that may contribute to persistent, disp...
Obesity Is Associated with Younger Age at Presentation and More Severe Cytopenias in Myelodysplastic Syndromes

Abstract INTRODUCTION Chronic inflammation and immune stimulation have been linked to the development of myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). Abnormal production of adipokines in obesity is known to cause increased oxidative stress and low-grade chronic systemic inflammation. Previous retrospective studies have reported that obesity was associated with increased risk of developing MDS and AML. It has also been suggested that obesity may be an adverse prognostic factor in MDS, resulting in decreased overall survival (OS) and increased risk of conversion to AML in certain subsets of MDS patients, particularly those with lower-risk disease. We sought to further define clinical characteristics associated with obesity in lower-risk MDS. METHODS We used our institution's data mining software to identify patients with biopsy-proven MDS or CMML diagnosed between 2001 and 2016. 88 patients with lower-risk disease (Very Low, Low or Intermediate risk by IPSS-R score) with a body mass index (BMI) documented at the time of diagnosis were selected for this retrospective study. 23 patients had a BMI ≥ 30 (Obese LR-MDS) and 65 patients had a BMI RESULTS Mean BMI was 35.1 kg/m2 in Obese LR-MDS and 23.7 kg/m2 in Non-Obese LR-MDS. Obese LR-MDS patients presented at a significantly younger age (mean age 66 vs. 72, p=0.04). Baseline hemoglobin was significantly lower in the Obese LR-MDS group (mean 8.4 vs. 9.3 g/dL, p=0.03) and so was baseline platelet count (mean 91 vs. 149 x 103/µL, p=0.03). Differences in OS between the two groups were non-significant. Rate of conversion to AML was higher in the Obese LR-MDS group but the difference was not statistically significant (17.4% vs. 6.2%, p=0.23). A higher proportion of patients in the Obese LR-MDS group ultimately required treatment with hypomethylating agents but difference was not statistically significant (39.1% vs. 21.5%, p=0.17). No cytogenetic anomalies were seen at a higher rate in the Obese LR-MDS group. CONCLUSION Obese patients with lower-risk MDS in our analysis presented at a significantly younger age and had more severe anemia and thrombocytopenia at the time of diagnosis than non-obese patients. The significant differences in hemoglobin and platelet count are strongly suggestive of dysfunctional hematopoiesis in obese lower-risk MDS patients. We were not able to corroborate the previously reported findings of decreased OS or increased risk of conversion to AML in this population. We hope to refine our data further with mutational analysis to delineate whether certain mutations have a strong association with obesity and lower-risk MDS. Download : Download high-res image (195KB) Download : Download full-size image Disclosures No relevant conflicts of interest to declare.
Evaluation and Management of Misophonia Using a Hybrid Telecare Approach: A Case Report

Decreased sound tolerance (DST) is a negative reaction to environmental sounds and is estimated to affect 3.5% of the population. This case report presents the evaluation and management of an adult female with severe, longstanding misophonia. Her evaluation included comprehensive audiometric testing (including uncomfortable loudness levels) and a detailed assessment of the impact of DST on her life. She enrolled in tinnitus retraining therapy and began receiving treatment aiming to facilitate habituation of bothersome environmental sounds. This case was complicated by the advent of the coronavirus disease 2019 (COVID-19) pandemic and a telemedicine hybrid approach was employed to increase access to audiologic care. Using this structure, some appointments occurred in person in the clinic and others occurred via a telemedicine video visit format. Telemedicine video visits facilitated in-depth discussions, afforded the opportunity to answer questions, and provided the option of cloud-based remote programming of on-ear devices. Future care will continue to employ a hybrid approach.
Sport and Recreational Causes of Nasal Bone Fractures.

OBJECTIVE Nasal bone fractures are the most common facial bone fractures. However, there is limited literature on the etiology of these fractures, particularly distribution across sports and other recreational activities. METHODS The Nationwide Electronic Injury Surveillance System (NEISS) national injury database was queried for emergency department visits involving the diagnosis of nasal or nose fractures associated with sports and recreation activities over the most recent 10 year span available. Demographic, disposition, and weighted incidence were analyzed. RESULTS Total incidence of nasal fractures across 10 years was 158 979. The mean age of nasal bone fractures was 20.4 years old. Nasal fractures were more common in males (74.6%) and white patients (54.1%). National estimated incidence of nasal fractures decreased from 21 028 in 2009 to 11 108 in 2018, a reduction of 47.2%. The most common causes among all patients were basketball (23.2%), baseball (17.1%), softball (9.8%), soccer (7.4%), and football (7%). In pediatric patients, the most common cause was baseball (25.1%). The majority (98.1%) of patients were discharged from the emergency department, while 0.9% of patients were admitted. CONCLUSION The most common recreational causes of nasal fractures are sports, with the most common being non-contact sports like basketball and baseball. However, the incidence of nasal bone fractures due to recreational causes nationwide has decreased significantly over the past 10 years. This may reflect improved safety protocols among athletes.
Design of a Portable Implementation of Partitioned Point-to-Point Communication Primitives

The Message Passing Interface (MPI) has been the dominant message passing solution for scientific computing for decades. MPI point-to-point communications are highly efficient mechanisms for process-to-process communication. However, MPI performance is slowed by concurrency protections in the MPI library when processes utilize multiple threads. MPI’s current thread-level interface imposes these overheads throughout the library when thread safety is needed. While much work has been done to reduce multithreading overheads in MPI, a solution is needed that reduces the number of messages exchanged in a threaded environment. Partitioned communication is included in the MPI 4.0 standard as an alternative that addresses the challenges of multithreaded communication in MPI today. Partitioned communication reduces overall message volume by creating a buffer-sharing mechanism between threads such that they can indicate when portions of a communication buffer are available to be sent. Separation of the control and data planes in MPI is enabled by allowing persistent initialization and single occurrence message buffer matching from the indication that the data is ready to be sent. This enables the usage of underlying hardware primitives like triggered operations, where commands (destination, size, etc.) can be set up prior to data buffer readiness with readiness triggered by a simple doorbell/counter later. This approach is useful for future development of MPI operations in environments where traditional networking commands can have performance challenges, like accelerators (GPUs, FPGAs). In this paper, we detail the design and implementation of a layered library (built on top of MPI-3.1) and an integrated Open MPI solution that supports the new, MPI-4.0 partitioned communication feature set. The library will enable applications to use currently released MPI implementations and older legacy libraries to provide partitioned communication support while also enabling further exploration of this new communication model in new applications and use cases. We will compare the designs of the library and native Open MPI support, provide performance results and comparisons between the two approaches, and lessons learned from the implementation of partitioned communication in both library and native forms. We find that the native implementation and library have similar performance with a percentage difference under 0.94% in microbenchmarks and performance within 5% for a partitioned communication enabled proxy application.
Structure and Mechanism of the Azobobacter vinelandii Fe-Protein

Transfer of electrons between the Fe-protein and the MoFe-protein of the nitrogenase complex is a highly specific reaction requiring that a number of criteria be satisfied. For example, the Fe-protein is the unique donor for the reduction of substrates. Low redox potential alone does not appear to be sufficient for electron transfer as other low potential electron carrier proteins are inactive. Futhermore, Fe-proteins having similar amino acid sequences will not necessarily be equally active i n heterocomp lexes with the MoFe-protein. Because electron transfer occurs in the binary complex of the MoFe-protein and the MgAXP:Fe-protein, the correct orientation of the proteins to align the electron donor and acceptor sites, as encoded in the primary sequences, must be maintained. After each cycle of electron transfer, the protein complex and hydrolyzed nucleotide must dissocate. (Where in the cycle the ATP is hydrolyzed has not been determined.)
A Statistical Method for Crack Detection from Vibrothermography Inspection Data

AbstractNondestructive evaluation methods are widely used in quality control processes for critical components in systems such as aircraft engines and nuclear power plants. These same methods are also used in periodic field inspection to assure that the system continues to be reliable while it is in service. This paper describes a detection algorithm to automatically analyze vibrothermography sequence-of-image inspection data used to detect cracks in jet engine fan blades. Principal components analysis is used for dimension reduction. Then the fitted coefficients of the first principal component are processed by using robust regression to produce studentized residuals that are used in the crack-detection rules. We also show how to quantify the probability of detection for the algorithm. The detection algorithm is both computationally efficient and accurate. It correctly identified several cracks in our experimental data that were not detected by the standard human visual inspection method.
Immunochemical studies on myosin. 3. Immunochemical comparison of myosins from chicken skeletal heart and smooth muscles.

Abstract 1. 1. Fluorescein-labelled antisera to 3 times precipitated skeletal muscle myosin are localized to the A bands of both skeletal and heart muscle myofibrils. This observation has suggested that cardiac- and skeletal-muscle myosins are immunologically closely related. 2. 2. Unpublished observations of certain peculiarities associated both with the fluorescence patterns of antibody stained cardiac myofibrils and with the gel-diffusion analyses of cardiac myosin vs. antisera, against skeletal-muscle myosin have raised doubts about the immunochemical relationships between the two myosins. 3. 3. The same and similar preparations of the myosins and their antisera which had been used in previous immunochemical studies on cardiac and skeletal-muscle myosins were used in the present gel-diffusion studies. Because smooth-muscle myosin is thought to be functionally and physicochemically similar to the other two myosins, its immunochemical relationships to them was also studied. 4. 4. The results show that the myosins obtained from the three different types of chicken muscle, if sufficiently purified, are immunochemically distinct from one another.
AlGaN/GaN HEMTs versus InAlN/GaN HEMTs fabricated by150-nm Y-gate process

Y-gate process with short gate length (150 nm) and low parasitic gate capacitance (25%-reduction than conventional T-gate process) was successfully developed using an i-line stepper. This simple process is suitable for mass-production of high speed GaN high-electron mobility transistors (HEMTs). With this process technology, we fabricated AlGaN/GaN HEMTs and InAlN/GaN HEMTs, respectively. We confirmed InAlN/GaN HEMTs are superior to AlGaN/GaN HEMTs in terms of DC and RF characteristics. We could obtain high transconductance g m of 460 mS/mm and high current gain cutoff frequency f T of 70 GHz by combination of InAlN/GaN HEMTs and Y-gate process.
Umbrella potential of plants and dragonflies for wetland conservation: a quantitative case study using the umbrella index

Summary 1 Shortcuts to measuring biodiversity enable prioritization of conservation effort in the face of limited time, personnel and funding. The conservation umbrella approach focuses management effort according to individual species that may confer protection to a larger community. This approach can help guide the management agenda towards attainable goals by maximizing conservation returns per unit effort. The development of the umbrella index has shown promise in identifying umbrella species in terrestrial ecosystems but has received little attention with respect to the management of wetland ecosystems. 2 We used the umbrella index to assess the umbrella potential of vascular plants and dragonflies (Odonata) from 15 wetland impoundments in northern Mississippi, USA. The presence of adult odonates was determined by repeated visual surveys and plant lists were compiled from 50 plots per site. 3 Umbrella schemes, or the sites occupied by top umbrella species, missed large numbers of beneficiary species and occurrences. With one exception, umbrella schemes failed to optimize conservation returns relative to randomized schemes in both assemblages. Also, umbrella schemes approximately equalled the performance of non-umbrella schemes both overall and for species with a low rate of occurrence. Low occurrence rates in both assemblages may have hindered umbrella index performance because the index assumes that species with moderate occurrence rates have the most umbrella potential. 4 Cross-taxon analyses (Mantel tests and McNemar tests) suggested transferability of plant and dragonfly umbrella schemes, and non-random association between the plants and dragonflies in these wetlands. 5 Synthesis and applications. Despite the questionable performance of umbrella schemes in our study, the use of a quantitative ecological tool such as the umbrella index instead of political or popularity criteria is strongly recommended for future selection of umbrella species. The results of cross-taxon analyses supported growing evidence for spatial and functional relationships between wetland macrophytes and adult odonates. We suggest that the more easily measured assemblage can be used to set priorities for wetland conservation planning in circumstances where human resources are constrained.
Chapter 1 Flagellar Amputation and Regeneration in Chlamydomonas

Publisher Summary In flagellar autotomy, Chlamydomonas cells shed their flagella in response to stressful conditions, including extremes of temperature or pH and the presence of noxious agents such as detergents or alcohols in the medium. It serves a protective function for cells in the environment—under adverse conditions the flagella are shed to minimize exposure to environmental stress. There is existence of two different signaling mechanisms for flagellar autotomy. One of these involves the influx of Ca 2+ from the medium through specific channels; the other is proposed to be dependent on the release of intracellular Ca 2+ stores. A rapid increase in inositol 1, 4, 5 triphosphate (IP 3 ) is associated with flagellar autotomy, probably acting to release intracellular calcium. In Chlamydomonas the regeneration of flagella has been studied to provide insight into the synthesis of proteins that constitute the flagella and to characterize mutants with defective flagellar assembly. The procedures described in this chapter are used to amputate flagella under conditions that allow continued cell viability and flagellar regeneration. The most widely used and adaptable procedure to any research or teaching laboratory is pH shock. Suction deflagellation presumably acts by pulling the flagella through the holes of a nitrocellulose filter while retaining the cells on the filter. Techniques have been developed to deflagellate small numbers of cells in each well of a 96-well culture dish. This helps identify mutants with defective flagellar regeneration. Wild-type cells begin to regenerate flagella after amputation. Flagellar length can be assayed by aligning the flagella on fixed cells with an ocular micrometer, which consists of a small glass disk that fits into the eyepiece of the microscope. The grid is calibrated by observing a field micrometer grid.
Test-driven development goes to school

In industry experiments using test-driven development (TDD), some researchers report significantly increased code quality over traditional test-last approaches. Not surprisingly computing and information technology educators have begun to call for the introduction of TDD into the curriculum. This paper explores the pedagogical experience to date in using a test-first approach in the classroom. Selected studies include four experience reports, one conceptual paper, and three experiments comparing TDD against control groups. Issues in operationalizing TDD across the curriculum are examined, including programming language assertion mechanisms, the feasibility of employing test frameworks, and the automated verification of student test plans. Recommendations derived from the literature are presented.
Treatment of Septic Shock with Immunotherapy

Sepsis is the thirteenth leading cause of death in the United States. Despite increased knowledge about its pathophysiology, availability of powerful antibiotics, and advanced diagnostic and monitoring techniques, mortality rates have not changed significantly over the past 30 years. Immunotherapy may improve outcome in the critically ill with sepsis, although trial results have been disappointing to date.
Some Static and Dynamic Aspects of Robust Bayesian Theory

In this presentation, I discuss two features of robust Bayesian theory that arise, naturally, when considering more than one decision maker: (1) On a question of statics — what opportunities are there for Bayesians to engage in cooperative decision making while conforming the group to a (mild) Pareto principle and expected utility theory? (2) On a question of dynamics — what happens, particularly in the short run, when a collection of Bayesian opinions are updated using Bayes’ rule, where each opinion is conditioned on shared data?
Nonlinear structural analysis of vehicle body panels

The large deflection–induced geometric nonlinearity of vehicle body panels under road shipping condition is investigated. The example structure presented is the door outer panel of a passenger car. Studies include nonlinear finite element analysis of displacements, stresses and normal modes, and fracture mechanics analysis for crack growth rate and fatigue life prediction involving large deflections. The modified Newton–Raphson method is employed for the nonlinear analysis, and the fracture mechanics analysis is based on the virtual crack closure technique to compute the structural energy release rate, G. Results show that although the panel transverse deflection is large, i.e. close to panel thickness at the container design loading level, the difference between linear and nonlinear solutions is not significant. The reason is that the panel midplane is not stretched excessively due to the nature of the constraints provided by the container. This situation exists for most vehicle body panels under shipping environments. Therefore, the linear analysis strategy currently used in automotive industry for shipping container design is feasible. The results of the fracture mechanics analysis indicate that the dominant failure mode for the assumed panel fatigue cracking is the opening mode or Mode–I and the panel fatigue life can be greatly improved by properly designing the shipping container.
Optical Evaluation of a Refractive Secondary Concentrator

Refractive secondary concentrators are being considered for solar thermal applications because of their ability to archive maximum efficiency through the use of total internal reflection for the concentration and distribution of solar energy. A prototype refractive secondary concentrator was built based on ray tracing analysis to demonstrate this collection and distribution concept. The design included a conical secondary concentrator and a faceted extractor. The objective of this effort was to functionally evaluate the performance of the refractive secondary concentrator/extractor prototype and to compare the results with modeling. Most of the light was found to exit the refractive secondary concentrator through the extractor. In addition, the degree of attenuation encountered by the light as it passed through the refractive secondary concentrator was of interest. Quantifying optical output and validating the modeling will provide further understanding of the efficiency of the prototype and will provide insight for additional design and materials selection activities.
Spontaneous, synchronous electrical activity in neonatal mouse cortical neurones

Spontaneous [Ca2+]i transients were measured in the mouse neocortex from embryonic day 16 (E16) to postnatal day 6 (P6). On the day of birth (P0), cortical neurones generated widespread, highly synchronous [Ca2+]i transients over large areas. On average, 52% of neurones participated in these transients, and in 20% of slices, an average of 80% participated. These transients were blocked by TTX and nifedipine, indicating that they resulted from Ca2+ influx during electrical activity, and occurred at a mean frequency of 0.91 min−1. The occurrence of this activity was highly centred at P0: at E16 and P2 an average of only 15% and 24% of neurones, respectively, participated in synchronous transients, and they occurred at much lower frequencies at both E16 and P2 than at P0. The overall frequency of [Ca2+]i transients in individual cells did not change between E16 and P2, just the degree of their synchronicity. The onset of this spontaneous, synchronous activity correlated with a large increase in Na+ current density that occurred just before P0, and its cessation with a large decrease in resting resistance that occurred just after P2. This widespread, synchronous activity may serve a variety of functions in the neonatal nervous system.
Shape memory alloy actuated robot prostheses: initial experiments

Describes the objectives of a project, which are to design artificial limbs that are lightweight, compact and dexterous, that mimic human anatomy and maintain a high lifting capability. The key to satisfying these objectives is the use of shape memory alloy (SMA) artificial muscles as actuators. A general methodology to find the placement of SMA wires to achieve desired ranges of motion is presented. Two experimental prototypes, emulating human skeletal structures that are actuated by SMA artificial muscles are described in detail.
Near-surface effect in self-diffusion in NbCx

A low diffusivity near-surface porotion of the self-diffusion profiles generated from thin films of 14C-containing tracer materials is noted in three compositions of NbCx. Although commonly observed in diffusion reearch and explained in many ways, it is believed to be caused in the present case by a “delayed tracer effect” wherein nonideal boundary conditions are created by the particular tracer deposition methods, and the tracer atoms continue to enter the specimen thro ughout the time of the diffusion annealing. In drei Verbindungen von NbCx wird ein oberflachennaher Anteil des Eigendiffusionsprofils mit niedriger Diffusionskonstante, der von dunnen Filmen aus 14C-haltigem Material herruhrt, nachgewiesen. Obwohl dieser Anteil allgemein in Diffusionsuntersuchungen beobachtet und in vielfaltiger Weise erklart wird, wird im vorliegenden Fall angenommen, das er durch den „verzogerten Tracer-Effekt” verursacht wird, wobei durch besondere Bedingungen der Tracer-Abla gerung nichtideale Randbedingungen geschaffen werden, und die Tracer-Atome wahrend der ganze n Zeit des Diffusionsgluhens in die Probe eindringen.
Antimicrobial Activity of Chlorhexidine Gluconate Against Natural and Artificial Contamination During Simulation of in-use Conditions

Commercial bottles containing chlorhexidine gluconate (antimicrobial skin cleanser), whether exposed to room atmosphere or experimentally inoculated with Staphylococcus aureus, Pseudomonas aeruginosa, Pseudomonas cepacia, and Proteus mirabilis, did not exhibit microbial growth.
Strength analysis of piezoceramic materials for structural considerations in energy harvesting for UAVs

Vibration energy harvesting has received considerable attention in the research community over the past decade. Typical vibration harvesting systems are designed to be added on to existing host structures and capture ambient vibration energy. An interesting application of vibration energy harvesting exists in unmanned aerial vehicles (UAVs), where a multifunctional approach, as opposed to the traditional method, is needed due to weight and aerodynamic considerations. The authors propose a multifunctional design for energy harvesting in UAVs where the piezoelectric harvesting device is integrated into the wing of a UAV and provides energy harvesting, energy storage, and load bearing capability. The brittle piezoceramic layer of the harvester is a critical member in load bearing applications; therefore, it is the goal of this research to investigate the bending strength of various common piezoceramic materials. Three-point bend tests are carried out on several piezoelectric ceramics including monolithic piezoceramics PZT-5A and PZT-5H, single crystal piezoelectric PMN-PZT, and commercially packaged QuickPack devices. Bending strength results are reported and can be used as a design tool in the development of piezoelectric vibration energy harvesting systems in which the active device is subjected to bending loads.
Circadian Activity and Noise Comparisons of Two Confined Groups with and without Reference to Clock Time

The gross behavior of two comparable groups of normal Ss including men, women, and children was measured continuously over a 2-wk. interval by noise and activity recordings. The second group differed from the first in that no clocks or other mechanical means of recording time were available. Both groups were under relatively identical conditions of isolated confinement in a simulated fallout shelter. Normal cues as to passage of time were not available due to the construction characteristics of the experimental chamber. Thermal and ventilation conditions were maintained at optimal levels. Both measures revealed highly positive correlations between the mean circadian patterns of the two groups. Noise and activity were also highly correlated within groups. Longitudinal comparisons of daily means revealed slightly decreasing noise trends after the fourth day of confinement. Such a trend was not generally apparent in either of the longitudinal activity plots.
Laser photolysis of dye-sensitized nanocapsules occurs via a photothermal pathway.

Light-addressable nanocapsules offer a powerful method for delivering spatiotemporally precise signals to cells. Thus far, the mechanism involved in the photolysis of nanocapsules has been opaque. This paper presents experimental evidence that rules out a photochemical pathway in favor of a photothermal mechanism in the far-red photolysis of dye-sensitized, lipid−vesicle based nanocapsules. Photolysis efficiency was unaffected by the presence of radical inhibitors, and mass spectrometry measurements confirmed that the photolytic process did not produce dye radicals. Measurements of dye quantum yield in the lipid membrane showed an inverse correlation between quantum yield of the dye and photolysis efficiency of the vesicle. The result is consistent with the notion that a decrease in quantum yield translates into more vibrational relaxation and thermal motion of the dye molecules in the membrane and thus more efficient photothermal disruption of the vesicle. Furthermore, we observed that the decrease in qu...
Educational Renegades: Dissatisfied Teachers as Drivers of Charter School Formation

The U.S. charter school movement has expanded rapidly, but this growth is geographically uneven at the school district level. Focusing on Arizona—which has the least restrictive charter school law in the United States—we use district variables to determine the factors driving charter market share in 41 districts. Included in our analysis is an explicit measure of teacher dissatisfaction, which is not found in past work. Like previous analyses, we find that greater private school penetration prompts charter formation. In addition, we find quantitative confirmation of the fieldwork of Hess, Maranto, & Milliman (2001) and others suggesting that dissatisfied district school teachers drive Arizona charter growth by starting and staffing those schools.
Earlier Low‐Dose TBI or DST Overcomes CD8+ T‐Cell‐Mediated Alloresistance to Allogeneic Marrow in Recipients of Anti‐CD40L

Treatment with a single injection of anti-CD40L (CD154) monoclonal antibody (mAb) and fully mismatched allogeneic bone marrow transplant (BMT) allows rapid tolerization of CD4+ T cells to the donor. The addition of in vivo CD8 T-cell depletion leads to permanent mixed hematopoietic chimerism and tolerance. We now describe two approaches that obviate the requirement for CD8 T-cell depletion by rapidly tolerizing recipient CD8 T cells in addition to CD4 cells. Administration of donor-specific transfusion (DST) to mice receiving 3 Gy total body irradiation (TBI), BMT and anti-CD40L mAb on day 0 uniformly led to permanent mixed chimerism and tolerance, compared with only 40% of mice receiving similar treatment without DST. In the absence of DST, moving the timing of 3 Gy TBI to day –1 or day –2 instead of day 0 led to rapid (by 2 weeks) induction of CD8+ cell tolerance, and also permitted uniform achievement of permanent mixed chimerism and donor-specific tolerance in recipients of anti-CD40L and BMT on day 0. These nontoxic regimens overcome CD8+ and CD4+ T-cell-mediated alloresistance without requiring host T-cell depletion, permitting the induction of permanent mixed chimerism and tolerance.
Genome-wide localization of exosome components to active promoters and chromatin insulators in Drosophila

Chromatin insulators are functionally conserved DNA-protein complexes situated throughout the genome that organize independent transcriptional domains. Previous work implicated RNA as an important cofactor in chromatin insulator activity, although the precise mechanisms are not yet understood. Here we identify the exosome, the highly conserved major cellular 3' to 5' RNA degradation machinery, as a physical interactor of CP190-dependent chromatin insulator complexes in Drosophila. Genome-wide profiling of exosome by ChIP-seq in two different embryonic cell lines reveals extensive and specific overlap with the CP190, BEAF-32 and CTCF insulator proteins. Colocalization occurs mainly at promoters but also boundary elements such as Mcp, Fab-8, scs and scs', which overlaps with a promoter. Surprisingly, exosome associates primarily with promoters but not gene bodies of active genes, arguing against simple cotranscriptional recruitment to RNA substrates. Similar to insulator proteins, exosome is also significantly enriched at divergently transcribed promoters. Directed ChIP of exosome in cell lines depleted of insulator proteins shows that CTCF is required specifically for exosome association at Mcp and Fab-8 but not other sites, suggesting that alternate mechanisms must also contribute to exosome chromatin recruitment. Taken together, our results reveal a novel positive relationship between exosome and chromatin insulators throughout the genome.
Intrastrain Differences in Serotonin and Norepinephrine in Discrete Areas of Rat Brain

Determination of levels of serotonin and norepinephrine in various brain areas of male Sprague-Dawley rats obtained from four different breeder-suppliers showed considerably different basal levels among the various groups, as well as differences in response to monoamine oxidase inhibitors.
Analysis of serial CT scans to assess template and catheter movement in prostate HDR brachytherapy.

Abstract Purpose As prostate high-dose-rate (HDR) brachytherapy becomes more prevalent, varying amounts of catheter displacement have been noted. To investigate the constancy of catheter position and its impact on dose distribution, we analyzed serial dosimetric CT scans. Methods and materials The data from 50 patients were analyzed. During initial CT treatment planning, transverse images of the implant volume were collected, and all structures were digitized into the Nucletron Brachytherapy Planning System. Digitally reconstructed radiographs were generated with rendering of the catheter tips, ischial tuberosity, and perineal template. The distance from each catheter tip to the template and to the ischial tuberosity was measured. The distance between the ischial tuberosity and the template was similarly measured. A second CT set was obtained at different intervals and compared with the first measurement to assess catheter and/or template movement. In 10 patients, the second CT set was obtained before the third fraction in both 2-mm and 5-mm slice sequences, and the latter was used to re-create the HDR plan. Results Although no interfraction catheter movement relative to the template was found, the template-catheter unit moved in a caudal direction between HDR fractions. The amount of displacement was time dependent: 2 mm before the second fraction, 8 mm before the third, and 10 mm before the fourth. When comparing the first HDR treatment with the third, median decreases in the following dosimetric parameters were noted: dose to 90% of the prostate volume, 35% ( r = 0–60); minimal dose to the base, 35% ( r = 17–65); and maximal dose to 1 cm 3 , 13% ( r = 3–19%). Conclusion The interstitial catheters did not slip within the template and were not caudally displaced independently but rather in conjunction with the template. The displacement occurred in a time-dependent fashion, and, without redress, significant dosimetric changes are encountered by the third fraction.
Expression of a functional non-ribosomal peptide synthetase module in Escherichia coli by coexpression with a phosphopantetheinyl transferase

Abstract Background: Non-ribosomal peptide synthetases (NRPSs) found in bacteria abd fungi are multifunctional enzymes that catalyze the synthesis of a variety of biologically important peptides. These enzymes are composed of modular units, each responsible for the activation of an amino acid to an aminoacyl adenylate and for the subsequent formation of an aminoacyl thioester with the sulfhydryl group of a 4′-phosphopantetheine moiety. Attempts to express these modules in Escherichia coli have resulted in recombinant proteins deficient in 4′-phosphopantetheine. The recent identification of a family of phosphopantetheinyl transferases (P-pant transferases) associated with NRPS have led us to investigate whether coexpression of NRPS modules with P-pant transferases in E. coli would lead to the incorporation of 4′-phosphopantetheine. Results: A truncated module of gramicidin S synthetase, PheAT(His 6 ), was expressed as a His 6 fusion protein in E. coli with and without Gsp, the P-pant transferase associated with gramicidin S synthetase. Although PheAT(His 6 ) expressed alone in E. coli catalyzed Phe-AMP formation from Phe and ATP, 80% of the PheAT(His 6 ) that was coexpressed with Gsp could form the Phe thioester in the presence of Phe and ATP. Conclusions: Our finding indicates the presence of an almost equimolar amount of 4′-phosphopantetheine covalently bound to the NRPS module PheAT(His 6 ), and that the functional expression of NRPS modules in E. coli is possible, provided that they are coexpressed with an appropriate P-pant transferase.
Neurochemical Effects of Environmental Chemicals: In Vitro and In Vivo Correlations on Second Messenger Pathwaysa

Polychlorinated biphenyls (PCBs) are persistent, bioaccumulative, toxic, and widely distributed environmental chemicals. There is now both epidemiological and experimental evidence that PCBs cause cognitive deficits; however, the underlying cellular or molecular mechanism(s) is not known. We have hypothesized that altered signal transduction/second messenger homeostasis by PCBs may be associated with these effects since second messengers in signal transduction pathways, such as calcium, inositol phosphates (IP), and protein kinase C (PKC), play key roles in neuronal development and their function. In vitro studies using cerebellar granule neurons and isolated organelle preparations indicate that ortho-PCBs increase intracellular free Ca2+ levels by inhibiting microsomal and mitochondrial Ca2+ buffering and the Ca2+ extrusion process. Ortho-PCBs also increase agonist-stimulated IP accumulation and cause PKC translocation at low micromolar concentrations where no cytotoxicity is observed. On the other hand, non-ortho-PCBs are not effective in altering these events. Further SAR studies indicate that congeners with chlorine substitutions favoring non-coplanarity are active in vitro, while congeners favoring coplanarity are relatively inactive. Subsequent in vivo studies have shown that repeated exposure to a PCB mixture, Aroclor 1254, increases PKC translocation and decreases Ca2+ buffering in the brain, similar to in vitro studies. These changes in vivo are associated with elevated levels of non-coplanar ortho-PCB congeners at levels equivalent to 40-50 microM in brain, the concentrations that significantly inhibited second messenger systems in neuronal cultures in vitro. Current research is focusing on PCB-induced alterations in second messenger systems following developmental exposure.
Non‐state governance and the Internet: civil society and the ICANN

Explores a number of the debates and justification used to support and advance non‐state governance of the Internet in the USA. Reviews public reports released leading up to the formation of the Internet Corporation for Assigned Names and Numbers (ICANN). Concludes that the scope herein is restricted to the jurisdictions and reasoning stated in the policy papers leading to the formation of the ICANN.
Energetic ion beam magnetosphere injection and solar power satellite transport

The effects of ion beam injection in the magnetosphere are considered. The beam's parameters are those characteristic of the ion propulsion engines envisioned for use in solar power satellite placement (Hanley and Guttman, 1978). Specifically, from a detailed analysis of the beam's propagation through the magnetosphere it is shown that the bulk of the ion beam is not stopped in the magnetosphere. However, the relatively small fraction of the beam which is deposited via the beam's sheath loss may give rise to a large distortion in the magnetospheric plasma population. Possible loss mechanisms from the magnetosphere for this artificial energetic ion component are evaluated. Electron Coulomb scattering yields the shortest lifetime throughout most of the plasmasphere provided that plasmasphere heating by beam ions is not too intense. Charge exchange dominates beyond the plasmasphere. The effects of pitch angle scattering due to beam ion turbulence may appreciably shorten beam ion lifetimes throughout the magnetosphere
Aerodynamic characteristics of swirling spray flames: Pressure-jet atomizer

Abstract The effect of swirl on droplet transport processes is examined in a pressure-atomized, hollow-cone kerosene spray, introduced into coflowing nonswirling and swirling air flow fields. An ensemble light scattering technique, based on measurement of the polarization ratio, provided spatially resolved measurements on the local values of droplet mean size and number density in dense regions of the nonburning spray. Laser velocimetry was employed to measure the axial, radial, and tangential velocity components of the droplets and combustion air stream. Droplet velocity distributions and time histories provided information on the transport of individual droplets under nonburning and burning conditions. High-speed cinematography, short-exposure photography, and video movies were also employed to observe the global features of the spray flame. The results reveal that the spray flame has a complex three-dimensional structure. The introduction of swirl to the combustion air modifies the droplet/air velocity field in addition to the spatial distribution of droplet size and number density. Larger droplets are transported downstream relatively unperturbed by the surrounding air stream while smaller droplets are entrained by the recirculating aerodynamic pattern. In addition, observed instabilities during liquid jet breakup appear to result in droplet clustering further downstream. The interaction between the fuel droplets and air flow field is therefore a process that significantly affects the overall characteristics of spray flames. Regulation of fuel/air interactions can mitigate fuel losses into the surrounding environment as well as control flame stability.
Improving computer-based problem solving training: The role of the teacher as mediator

Abstract A number of studies have examined computer games in the classroom in the context of characteristics of the learner and characteristics of the learning environment. The present article examined the role of the teacher in computer-based problem solving. Rocky's Boots (RB) was used as an environment for analyzing the importance and role of the teacher in computer-based problem solving training. The present study provided a systematic examination of the ways in which a teacher might augment the RB program to incorporate a metacognitive emphasis into the training. Specifically examined were: (1) the level of problem solving that sixth grade children could reach in RB without teacher assistance; and (2) the amount and type of help necessary to advance their problem solving performance. Results indicated that all children reached a plateau in this performance. Children were advanced beyond that plateau by teacher intervention. Results are discussed in terms of suggestions for improving RB tutorials and advancing the potential role of the teacher as a critical element in computer-based training.
A Survey of Sensor Selection Schemes in Wireless Sensor Networks

One of the main goals of sensor networks is to provide accurate information about a sensing field for an extended period of time. This requires collecting measurements from as many sensors as possible to have a better view of the sensor surroundings. However, due to energy limitations and to prolong the network lifetime, the number of active sensors should be kept to a minimum. To resolve this conflict of interest, sensor selection schemes are used. In this paper, we survey different schemes that are used to select sensors. Based on the purpose of selection, we classify the schemes into (1) coverage schemes, (2) target tracking and localization schemes, (3) single mission assignment schemes and (4) multiple missions assignment schemes. We also look at solutions to relevant problems from other areas and consider their applicability to sensor networks. Finally, we take a look at the open research problems in this field.
Traffic-Aware Channel Assignment in Enterprise Wireless LANs

Campus and enterprise wireless networks are increasingly characterized by ubiquitous coverage and rising traffic demands. Efficiently assigning channels to access points (APs) in these networks can significantly affect the performance and capacity of the WLANs. The state-of-the-art approaches assign channels statically, without considering prevailing traffic demands. In this paper, we show that the quality of a channel assignment can be improved significantly by incorporating observed traffic demands at APs and clients into the assignment process. We refer to this as traffic-aware channel assignment. We conduct extensive trace-driven and synthetic simulations and identify deployment scenarios where traffic-awareness is likely to be of great help, and scenarios where the benefit is minimal. We address key practical issues in using traffic-awareness, including measuring an interference graph, handling non-binary interference, collecting traffic demands, and predicting future demands based on historical information. We present an implementation of our assignment scheme for a 25-node WLAN testbed. Our testbed experiments show that traffic-aware assignment offers superior network performance under a wide range of real network configurations. On the whole, our approach is simple yet effective. It can be incorporated into existing WLANs with little modification to existing wireless nodes and infrastructure.
Challenges in Offering Inner-City After-School Physical Activity Clubs

Background: Offering physical activity clubs (PACs) for students in urban high schools can provide avenues for increased physical activity (PA); however, little is known about why some clubs are not successful. Purpose: The purpose of this qualitative study was to examine leaders' and students' perspectives on the challenges faced when implementing PACs. Methods: Field observations (n = 115) and interviews with students (n = 278) and adult leaders (n = 126) were conducted over 2 years. The population-based health promotion model (PHPM) was used to analyze and interpret complex interrelationships. Results: Four themes emerged: (1) finding consistently available facility space, (2) providing snacks for adolescents, (3) securing reliable transportation, and (4) balancing clubs with other after-school obligations. Discussion: Leader and students reported challenges that intersected at all 3 streams: upstream, midstream, and downstream. With economic poverty within the community presenting as an upstream chall...