gebhart/patrepeval huggingface dataset:
Cone-beam reconstruction using the backprojection of locally filtered projections (2005)

This paper describes a flexible new methodology for accurate cone beam reconstruction with source positions on a curve (or set of curves). The inversion formulas employed by this methodology are based on first backprojecting a simple derivative in the projection space and then applying a Hilbert transform inversion in the image space. The local nature of the projection space filtering distinguishes this approach from conventional filtered-backprojection methods. This characteristic together with a degree of flexibility in choosing the direction of the Hilbert transform used for inversion offers two important features for the design of data acquisition geometries and reconstruction algorithms. First, the size of the detector necessary to acquire sufficient data for accurate reconstruction of a given region is often smaller than that required by previously documented approaches. In other words, more data truncation is allowed. Second, redundant data can be incorporated for the purpose of noise reduction. The validity of the inversion formulas along with the application of these two properties are illustrated with reconstructions from computer simulated data. In particular, in the helical cone beam geometry, it is shown that 1) intermittent transaxial truncation has no effect on the reconstruction in a central region which means that wider patients can be accommodated on existing scanners, and more importantly that radiation exposure can be reduced for region of interest imaging and 2) at maximum pitch the data outside the Tam-Danielsson window can be used to reduce image noise and thereby improve dose utilization. Furthermore, the degree of axial truncation tolerated by our approach for saddle trajectories is shown to be larger than that of previous methods.
A normal distribution for tensor-valued random variables: applications to diffusion tensor MRI (2003)

Diffusion tensor magnetic resonance imaging (DT-MRI) provides a statistical estimate of a symmetric, second-order diffusion tensor of water, D, in each voxel within an imaging volume. We propose a new normal distribution, p(D) alpha exp(-1/2 D: A: D), which describes the variability of D in an ideal DT-MRI experiment. The scalar invariant, D : A : D, is the contraction of a positive definite symmetric, fourth-order precision tensor, A, and D. A correspondence is established between D: A: D and the elastic strain energy density function in continuum mechanics--specifically between D and the second-order infinitesimal strain tensor, and between A and the fourth-order tensor of elastic coefficients. We show that A can be further classified according to different classical elastic symmetries (i.e., isotropy, transverse isotropy, orthotropy, planar symmetry, and anisotropy). When A is an isotropic fourth-order tensor, we derive an explicit analytic expression for p(D), and for the distribution of the three eigenvalues of D, p(gamma1, gamma2, gamma3), which are confirmed by Monte Carlo simulations. We show how A can be estimated from either real or synthetic DT-MRI data for any given experimental design. Here we propose a new criterion for an optimal experimental design: that A be an isotropic fourth-order tensor. This condition ensures that the statistical properties of D (and quantities derived from it) are rotationally invariant. We also investigate the degree of isotropy of several DT-MRI experimental designs. Finally, we show that the univariate and multivariate distributions are special cases of the more general tensor-variate normal distribution, and suggest how to generalize p(D) to treat normal random tensor variables that are of third- (or higher) order. We expect that this new distribution, p(D), should be useful in feature extraction; in developing a hypothesis testing framework for segmenting and classifying noisy, discrete tensor data; and in designing experiments to measure tensor quantities.
Self‐sustained n‐type memory transistor devices based on natural cellulose paper fibers (2009)

Abstract Reported herein is the architecture for a nonvolatile n‐type memory paper field‐effect transistor. The device was built via the hybrid integration of natural cellulose fibers (pine and eucalyptus fibers embedded in resin with ionic additives), which act simultaneously as substrate and gate dielectric, using passive and active semiconductors, respectively, as well as amorphous indium zinc and gallium indium zinc oxides for the gate electrode and channel layer, respectively. This was complemented by the use of continuous patterned metal layers as source/drain electrodes.
Detection and imaging of arbitrarily moving targets with single-channel SAR (2003)

In synthetic aperture radar (SAR) images, moving targets cause imaging errors like defocusing and/or displacement, depending on the direction of their motion. In order to get a correct and focused image of the moving targets, the knowledge of the target parameters position and velocity is necessary. Here, an algorithm for detection, parameter estimation, and imaging of ground-based targets, moving in arbitrary directions, is presented. The algorithm is based on evaluation of a sequence of single-look SAR images which is generated from conventional, single-channel SAR raw data. Position and velocity of the moving targets are estimated by applying two observation models, whereby aliasing due to a motion-induced Doppler shift is considered. In this way, the moving targets can be detected almost independent of their moving direction. The estimated parameters are used to compensate for the imaging errors in the SAR images. Finally, the real motion of the targets in the scene is visualised in a compensated image sequence.
Mesenchymal Stem Cell Population Derived from Human Pluripotent Stem Cells Displays Potent Immunomodulatory and Therapeutic Properties (2014)

Mesenchymal stem cells (MSCs) are being tested in a wide range of human diseases; however, loss of potency and inconsistent quality severely limit their use. To overcome these issues, we have utilized a developmental precursor called the hemangioblast as an intermediate cell type in the derivation of a highly potent and replenishable population of MSCs from human embryonic stem cells (hESCs). This method circumvents the need for labor-intensive hand-picking, scraping, and sorting that other hESC-MSC derivation methods require. Moreover, unlike previous reports on hESC-MSCs, we have systematically evaluated their immunomodulatory properties and in vivo potency. As expected, they dynamically secrete a range of bioactive factors, display enzymatic activity, and suppress T-cell proliferation that is induced by either allogeneic cells or mitogenic stimuli. However, they also display unique immunophenotypic properties, as well as a smaller size and >30,000-fold proliferative capacity than bone marrow-derived MSCs. In addition, this is the first report which demonstrates that hESC-MSCs can inhibit CD83 up-regulation and IL-12p70 secretion from dendritic cells and enhance regulatory T-cell populations induced by interleukin 2 (IL-2). This is also the first report which shows that hESC-MSCs have therapeutic efficacy in two different autoimmune disorder models, including a marked increase in survival of lupus-prone mice and a reduction of symptoms in an autoimmune model of uveitis. Our data suggest that this novel and therapeutically active population of MSCs could overcome many of the obstacles that plague the use of MSCs in regenerative medicine and serve as a scalable alternative to current MSC sources.
Co-axial Micro-Cathode Arc Thruster (CA-uCAT) and Performance Characterization (2011)

mCAT) named Co-axial Micro-Cathode Arc Thruster (CA-mCAT) has been designed. The behavior of the CAmCAT was studied and characterized in this paper. A half-ball shape Langmuir probe was employed to measure the total ion current over the thruster arc current. It is found that new thruster design (CA-mCAT) yields the transport eciency of around 45% without need in application magnetic eld, and this is close to the maximum ratio for mCAT when magnetic eld was utilized. To optimize the performance of CAmCAT , the magnetic eld eect on CAmCAT have been studied. Four assembled Langmuir probes were developed to characterize the rotation of the cathode spot as a result of an applied magnetic eld. It is found that an applied magnetic eld leads to an increase of cathode spots rotational speed. Also, the velocity of ions moving from the CA-mCAT cathode spots were measured using a set of grid probes along the path of the plasma plume expansion. It was found that the ion drift velocity had increased when magnetic eld increased (from 0mT up to 300mT). The average ion velocity increases with the increase of magnetic eld by factor of 2-3 up to about (5-6) 10 4 m /s with an applied magnetic eld strength of 300mT.
Untangling mixed information to calibrate resource utilization in virtual machines (2011)

Server virtualization brings benefits in autonomic resource management, but also leads to new challenges. The challenge the paper addresses is on profiling physical resource utilization information of VMs when consolidated on a single server. Profiling is very difficult due to dynamic mapping relationships of resource activities between the virtual layer and the physical layer. The problem is further exacerbated by cross-resource utilization causality relationships due to virtualization overhead and resource utilization multiplexing across different VMs. We formulate profiling as a source separation problem as studied in digital signal processing, and design a directed factor graph (DFG) to model the multivariate dependence relationships among different resources (CPU, memory, disk, network) across virtual and physical layers. A benchmark based methodology is designed to build a DFG based model for the VM information calibration problem. A run-time calibration mechanism is proposed based on the DFG based model and further enhanced with a robust remodeling method based on guided regression. The proposed methodology outputs estimates of physical resource utilization on individual VMs and physical server aggregate resource utilization. We present a case study using the Xen-virtualization platform and evaluate the methodology for different consolidation scenarios with diverse applications including RUBiS, IOzone, SysBench, and Netperf. The results show that the DFG calibration significantly improves the accuracy of the resource utilization information collected within guest VMs as it reduces relative errors in CPU utilization from 44.8% down to 3.9% for CPU-intensive applications and relative errors in disk write rate from 391.5% down to 10.6% for IO-intensive applications, strongly arguing for the effectiveness of the proposed DFG calibration methodology.
A New Class of Planar Ultrawideband Modular Antenna Arrays With Improved Bandwidth (2017)

The theory, design, fabrication, and measurement of a new class of planar ultrawideband modular antenna (PUMA) arrays are presented. The proposed PUMA array class achieves twice the bandwidth (from 3:1 to 6:1) of the conventional shorted via-based PUMA without using an external matching network and while retaining convenient unbalanced feeding, manufacturing, and assembly characteristics. The chief enabling technical innovation hinges upon the reconfiguration of shorting vias into capacitively-loaded vias that simultaneously: 1) mitigate low-frequency bandwidth-limiting loop modes and 2) shift problematic common-mode resonances out-of-band. A simple theoretical model based on ridged waveguides is proposed that qualitatively and quantitatively explains this novel common-mode mitigation. An infinite array operating over 3.53-21.2 GHz (6:1) is designed to achieve active VSWR <; {2, 2.5, 3.8} while scanning to {broadside, 45°, 60°}, respectively, without oversampling the aperture. D-plane cross-polarization is around {-15, -10} dB for {45°, 60°} scans with high efficiency, i.e., 0.5 dB co-polarized gain loss on average. A dual-polarized prototype 256-port (128 elements per polarization) array is fabricated and measured having good agreement with full-wave finite array simulations.
Biological and chemotherapeutic studies on three semisynthetic cephamycins. (1978)

Three semisynthetic cephamycin antibiotics (7alpha-methoxy-cephalosporins), SK&F 73678, SK&F 83088 (CS-1170) and cefoxitin, have been found to possess favorable biological and chemotherapeutic properties. All three cephamycins are active in vitro against strains of Staphylococcus aureus and a variety of gram-negative bacilli. Beta-lactamase producing organisms including indole-producing Proteus spp., Enterobacter spp. and Serratia strains as well as certain anaerobic bacteria were found to be susceptible to these antibiotics. SK&F 73768 showed somewhat better MIC values than cefoxitin against multiple strains of bacteria. Strains of Pseudomonas aeruginosa and group D streptococci are essentially insensitive to these compounds. Their binding to serum proteins is relatively low. In mice, cefoxitin showed the most favorable pharmacokinetics with respect to peak serum level, serum half-life and urinary recovery. These cephamycins protected mice experimentally infected with a variety of bacterial strains. All three compounds are rapidly bacteriolytic to the logarithmically growing Escherichia coli and belatedly so to Staphylococcus strains with complete sterilizing effect. SK&F 73678 and SK&F 83088 showed activity and potency comparable to or better than cefoxitin and thus can be considered candidates for clinical study.
Six approaches to limited domain concatenative speech synthesis (2006)

This paper (based on an MS Thesis by Robert Utama in the Electrical and Computer Engineering department at Rutgers University) describes 6 limited-domain Text-to-Speech (TTS) systems that are constrained to the digit string and natural number domains (cardinal numbers only). Each of the 6 unit selection-based concatenative TTS systems were implemented in MATLAB. We evaluate and discuss various factors that influenced the naturalness or overall quality of the synthesized voice. Some of the factors studied were the length and type of the synthesis unit and the extent of co-articulation represented in the recorded speech database. We show that it is possible to create a high quality limited domain TTS system either with maximal or with carefully controlled minimal effects of co-articulation.
Proportional Myoelectric Control of Robots: Muscle Synergy Development Drives Performance Enhancement, Retainment, and Generalization (2015)

Proportional myoelectric control has been proposed for user-friendly interaction with prostheses, orthoses, and new human-machine interfaces. Recent research has stressed intuitive controls that mimic human intentions. However, these controls have limited accuracy and functionality, resulting in user-specific decoders with upper-bound constraints on performance. Thus, myoelectric controls have yet to realize their potential as a natural interface between humans and multifunctional robotic controls. This study supports a shift in myoelectric control schemes toward proportional simultaneous controls learned through the development of unique muscle synergies. A multiple day study reveals natural emergence of a new muscle synergy space as subjects identify the system dynamics of a myoelectric interface. These synergies correlate with long-term learning, increasing performance over consecutive days. Synergies are maintained after one week, helping subjects retain efficient control and generalize performance to new tasks. The extension to robot control is also demonstrated with a robot arm performing reach-to-grasp tasks in a plane. The ability to enhance, retain, and generalize control, without needing to recalibrate or retrain the system, supports control schemes promoting synergy development, not necessarily user-specific decoders trained on a subset of existing synergies, for efficient myoelectric interfaces designed for long-term use.
SU-EE-A2-06: Using Multi-Element Detector Arrays for Commissioning Active Wobbling and Energy-Stacking Proton Beams (2007)

Multi-element detector arrays were constructed to characterize the properties of active wobbling and energy-stacking proton beam commissioning. A multi-layer ionization chamber (MLIC) array measured depth doses, and a multi-pad ionization chamber (MPIC) array measured lateral profiles. The MLIC consists of 122 chambers with 1.82mm spatial resolution and has an effective physical density about 60% that of water. The MPIC consists of 128 chambers arranged in two 38cm long orthogonal lines with spatial resolution of 5mm within 10cm radius and 7mm outwardly. During performance tests on the MLIC and MPIC, good collection efficiency with superior reproducibility and linearity were achieved. The relative variation on the sensitivity for each individual chamber was carefully calibrated before use for proton beam characterization. The relatively small charge collection area (6mm in diameter) and volume (0.3 cm3) of each chamber has a well guarded lead and allows one to study the effect of field size on depth dose distributions for fields of approximately 2 cm to 10 cm in diameter. The MLIC is calibrated using a pristine proton beam with range 27cm in water. To calibrate the large dimensional MPIC, uniform lateral dose distributions in water within 1% were generated. Analytical functions were applied to fit measured depth dose and lateral distributions in water during the calibrations. With proper calibrations, the uncertainties of measured depth doses and lateral profiles with these multi-element detector arrays were within 1% with respect to ones measured point by point with an ion chamber in a water phantom. Significant time savings for beam measurements were thus achieved.
Resorbable calcium phosphate bone substitute (1998)

The in vitro and in vivo properties of a novel, fully resorbable, apatitic calcium phosphate bone substitute (ABS) are described. The ABS was prepared from calcium phosphate precursors that were hydrated to form an injectable paste that hardens endothermically at 37 °C to form a poorly crystalline apatitic calcium phosphate (PCA). The PCA reaction product is stable in vivo as determined by FTIR and XRD analysis of rabbit intramuscular implants of ABS retrieved 4, 7, and 14 days postimplantation. Bone formation and resorption characteristics of the ABS material were characterized in a canine femoral slot defect model. Femoral slot defects in dogs were filled with either autologous bone implants or the ABS material. Sections of femoral bone defect site from animals sacrificed at 3, 4, 12, 26, and 52 weeks demonstrated that new bone formation proceeded similarly in both autograft and ABS filled slots. Defects receiving either material were filled with trabecular bone in the first 3 to 4 weeks after implantation; lamellar or cortical bone formation was well established by week 12. New bone formation in ABS filled defects followed a time course comparable to autologous bone graft filled defects. Histomorphometric evaluation of ABS resorption and new bone formation indicated that the ABS material was greater than 99% resorbed within 26 weeks; residual ABS occupied 0.36 ± 0.36% (SEM, n = 4) of the original defect area at 26 weeks. Quantitatively and qualitatively, the autograft and ABS were associated with similar new bone growth and defect filling characteristics. © 1998 John Wiley & Sons, Inc. J Biomed Mater Res (Appl Biomater) 43: 399–409, 1998
Imperceptible Polychromatic Visual Stimuli for Brain-Display Interfaces (2014)

Steady-state visual evoked potentials (SSVEPs) are responses to repetitive stimuli modulated at a constant temporal frequency on the central retina [1]. Using SSVEPs, Brain-computer interface (BCI) is an interactive system with high potentials. And brain-display interactive (BDI) systems can be regarded as a special type of exogenous BCIs, in which images appear on the displays are used as stimuli to evoke electroencephalographic (EEG) responses from viewers’ visual cortices. For the practical purpose of inducing strong responses, most SSVEP-BCIs employ visual stimuli in the low-frequency band, which causes visual fatigue, migraine headaches and occasionally seizures.
Abstract A042: Keratin 17 is a negative prognostic and predictive biomarker in pancreatic ductal adenocarcinoma (2022)

Abstract Background: There is an urgent need to understand why patients with clinically and histologically identical pancreatic ductal adenocarcinomas (PDACs) differ in response to treatment, disease progression, and survival. Although two standard chemotherapies are available, predictive biomarkers to guide regimen selection have not been defined. We previously reported that keratin 17 (K17) expression is a hallmark of PDAC cases with shortest patient survival. Furthermore, K17, explored using in vitro and in vivo murine models, drives resistance to gemcitabine and 5-fluorouracil, the most common chemotherapeutic agents in the two chemotherapies. Here, we aimed to validate the prognostic value of K17 and to further explore its role as a predictive biomarker. Methods: We used a cohort of 305 cases, with localized disease and who had gone tumor resection. An indirect immunoperoxidase method was used to detect K17 expression on surgical specimens, as previously described. Survival was plotted using the Kaplan–Meier method and hazard ratios (HRs) were calculated using Cox proportional hazard regressions for both, overall survival (OS) and progression-free survival (PFS). Results: Patients in the high-K17 expression group had shorter overall survival [median=25 mo., HR=1.511, p=0.0338] than those in the low-K17 expression group (median=42 mo.). In addition, high K17 expression was associated with shorter median OS (p=0.0280) and PFS (p=0.0434) in patients who were treated with gemcitabine (GEM) or with Gemcitabine/nab-Paclitaxel (GEMTAX) therapy (OS p=0.1959, PFS p=0.0724), compared to low-K17 counterparts. When we further separated our cohort by K17 level of expression and compared GEM and GEMTAX responses, we found that patients with tumors with high K17 expression do not benefit from GEMTAX adjuvant therapy (p=0.0356). Of note, K17 expression within the responder group was significantly lower than in tumors within the non-responder group for both Gem and GEMTAX (p&lt;0.001). Conclusions: K17 expression is confirmed as a robust prognostic biomarker, significantly correlated with poor OS and PFS in two independent cohorts of PDAC patients. More importantly, our results indicate that K17 expression predicts PDAC resistance to gemcitabine and poor response to GEMTAX. Collectively, our findings have implications could guide the development of K17 as a predictive biomarker for gemcitabine-based interventions in both adjuvant and palliative settings, to optimize therapeutic efficacy for PDAC. Citation Format: Lyanne Oblein, Lucia Roa-Peña, Sruthi Babu, Felicia D. Allard, Natalia D. Marchenko, Luisa F. Escobar-Hoyos, Kenneth R. Shroyer. Keratin 17 is a negative prognostic and predictive biomarker in pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr A042.