“HURP on” we're off to the kinetochore!

RanGTP has a central role in spindle assembly, but the Ran-regulated factors required to initiate spindle bipolarity and stabilize MT growth toward the chromosomes remain unknown. However, three recent papers (Koffa et al., 2006; Sillje et al., 2006; Wong and Fang, 2006) have identified a single factor, HURP, that may encompass both of these properties

Asymptotic behavior at infinity of solutions of multidimensional second kind integral equations

We consider second kind integral equations of the form x(s) - (abbreviated x - K x = y ), in which Ω is some unbounded subset of Rn. Let Xp denote the weighted space of functions x continuous on Ω and satisfying x (s) = O(|s|-p ),s → ∞We show that if the kernel k(s,t) decays like |s — t|-q as |s — t| → ∞ for some sufficiently large q (and some other mild conditions on k are satisfied), then K ∈ B(XP) (the set of bounded linear operators on Xp), for 0 ≤ p ≤ q. If also (I - K)-1 ∈ B(X0) then (I - K)-1 ∈ B(XP) for 0 < p < q, and (I- K)-1∈ B(Xq) if further conditions on k hold. Thus, if k(s, t) = O(|s — t|-q). |s — t| → ∞, and y(s)=O(|s|-p), s → ∞, the asymptotic behaviour of the solution x may be estimated as x (s) = O(|s|-r), |s| → ∞, r := min(p, q). The case when k(s,t) = к(s — t), so that the equation is of Wiener-Hopf type, receives especial attention. Conditions, in terms of the symbol of I — K, for I — K to be invertible or Fredholm on Xp are established for certain cases (Ω a half-space or cone). A boundary integral equation, which models three-dimensional acoustic propaga-tion above flat ground, absorbing apart from an infinite rigid strip, illustrates the practical application and sharpness of the above results. This integral equation mod-els, in particular, road traffic noise propagation along an infinite road surface sur-rounded by absorbing ground. We prove that the sound propagating along the rigid road surface eventually decays with distance at the same rate as sound propagating above the absorbing ground

The Demographic Imperative in Religious Change in the United States

U.S. Protestants are less likely to belong to “mainline” denominations and more likely to belong to “conservative” ones than used to be the case. Evidence from the General Social Survey indicates that higher fertility and earlier childbearing among women from conservative denominations explains 76% of the observed trend for cohorts born between 1903 and 1973: conservative denominations have grown their own. Mainline decline would have slowed in recent cohorts, but a drop‐off in conversions from conservative to mainline denominations prolonged the decline. A recent rise in apostasy added a few percentage points to mainline decline. Conversions from mainline to conservative denominations have not changed, so they played no role in the restructuring

Path Plan Performance Evaluation of the Challenge 1: A Small Unmanned Surface Vehicle for Radiation Detection and Mapping

This thesis will compare the performance of the Challenge 1 unmanned surface vehicle when autonomously conducting a radiological survey of a bounded, obstacle free, convex polygon via a traditional raster scan versus a novel spiral-like path plan. Currently, unmanned ground vehicles (UGV), unmanned aerial vehicles (UAV), and unmanned surface vehicles (USV) use a simple raster scan to insure complete coverage of a predefined, obstacle free area. Raster scans require a 180 degree change in heading which is easy for tracked UGVs and vertical take-o_ UAVs to accomplish, but more difficult for marine vehicles and fixed winged UAVs. A spiral-like path plan will not completely eliminate turns close to 180 degrees, but presents the possibility of removing the number of sharp turns at the expense of adding more slight turns. The author of this thesis originally hypothesized that this spiral-like path plan would result in shorter autonomous surveys by the Challenge 1 USV, as well as a higher percentage of coverage. Shorter surveys will allow operators such as the mission specialist overseeing a disaster in which radiological material may be present or treaty verification inspectors searching a facility to conduct more surveys in a limited time, which therefore increases the total area searched over this time period as well as provides data to the mission specialist faster. A higher percentage of coverage attained by the spiral-like path plan would guarantee a more complete representation of the area surveyed. To test this hypothesis the author used the 1.15 acre pond at John Crompton Park in College Station, Texas, to generate twenty-five unique convex polygons via teleoperation of the Challenge 1, ranging in size from 450 square meters to 1027 square meters, to which a raster path plan and spiral-like path plan were each used by the Challenge 1 to survey the area, resulting in fifty total runs. Following the data collection, the associated log from each run was used to calculate total survey time, total survey distance, root mean square of cross-track error, Hausdorff Distance (max RMS error), percent coverage, and percent of survey locations inside the bounded convex polygon. The average survey time for a spiral like path plan versus a raster scan was 13.68 seconds shorter (p < :59). The average total distance for a raster path versus a spiral like path was 15.53 meters less (p < :061). The average RMS of cross-track error for a spiral like path plan versus a spiral path plan was 0.31 meters less (p < :123). The average Hausdorff Distance for a spiral like path plan versus a raster scan was 1.53 meters less (p < 0:0005). The average of percent coverage for a raster scan versus a spiral like path was 4:22% higher (p < 0:027). The average of percentage of locations in the bounding area for a raster path versus a spiral like path was 16:88% higher (p < 0:00023). This shows that for α = :05, there is no statistical difference between either of the two path plans for survey time, survey distance, or RMS of cross-track error. However, there is a statistical difference between the two path plans for Hausdorff Distance, percent coverage and percentage of locations inside the bounding area. Due to the spiral path plan's inability to maintain locations inside the bounding area, a raster scan is the best path plan to use when surveying a bounded convex polygon with the Challenge 1 since it results in the highest percentage of coverage with no statistical difference in survey time, survey distance, or RMS of cross-track error. This result is only guaranteed for the Challenge 1 and its associated controller, with potentially different outcomes if tested on other surfaces vehicles, especially those with underwater propellers, rudders, or jet pump (no propeller or rudder) propulsion systems

Hematemesis, a Distended Abdomen, and Pulseless Electrical Activity – An Unusual Presentation of Boerhaave’s Syndrome

Case Presentation An 82-year-old male with a past medical history significant for coronary artery disease with three stents placed over the last 15 months, diastolic heart failure with preserved EF, atrial fibrillation on warfarin, colon cancer status-post sigmoid resection and prostate cancer status-post prostatectomy who presented with three episodes of melena, hematemesis, and weakness. The patient was in his usual state of health prior to these symptoms. He had no history of gastrointestinal (GI) bleeding or other GI pathology and was a non-drinker and non-smoker. He denied frequent use of non-steroidal anti-inflammatory medications

High-frequency bounds for the Helmholtz equation under parabolic trapping and applications in numerical analysis

This paper is concerned with resolvent estimates on the real axis for the Helmholtz equation posed in the exterior of a bounded obstacle with Dirichlet boundary conditions when the obstacle is \emph{trapping}. There are two resolvent estimates for this situation currently in the literature: (i) in the case of {\em elliptic trapping} the general ``worst case'' bound of exponential growth applies, and examples show that this growth can be realised through some sequence of wavenumbers; (ii) in the prototypical case of {\em hyperbolic trapping} where the Helmholtz equation is posed in the exterior of two strictly convex obstacles (or several obstacles with additional constraints) the nontrapping resolvent estimate holds with a logarithmic loss. This paper proves the first resolvent estimate for {\em parabolic trapping} by obstacles, studying a class of obstacles the prototypical example of which is the exterior of two squares (in 2-d), or two cubes (in 3-d), whose sides are parallel. We show, via developments of the vector-field/multiplier argument of Morawetz and the first application of this methodology to trapping configurations, that a resolvent estimate holds with a polynomial loss over the nontrapping estimate. We use this bound, along with the other trapping resolvent estimates, to prove results about integral-equation formulations of the boundary value problem in the case of trapping. Feeding these bounds into existing frameworks for analysing finite and boundary element methods, we obtain the first wavenumber-explicit proofs of convergence for numerical methods for solving the Helmholtz equation in the exterior of a trapping obstacle

Resource-constrained FPGA Design for Satellite Component Feature Extraction

The effective use of computer vision and machine learning for on-orbit applications has been hampered by limited computing capabilities, and therefore limited performance. While embedded systems utilizing ARM processors have been shown to meet acceptable but low performance standards, the recent availability of larger space-grade field programmable gate arrays (FPGAs) show potential to exceed the performance of microcomputer systems. This work proposes use of neural network-based object detection algorithm that can be deployed on a comparably resource-constrained FPGA to automatically detect components of non-cooperative, satellites on orbit. Hardware-in-the-loop experiments were performed on the ORION Maneuver Kinematics Simulator at Florida Tech to compare the performance of the new model deployed on a small, resource-constrained FPGA to an equivalent algorithm on a microcomputer system. Results show the FPGA implementation increases the throughput and decreases latency while maintaining comparable accuracy. These findings suggest future missions should consider deploying computer vision algorithms on space-grade FPGAs.Comment: 9 pages, 7 figures, 4 tables, Accepted at IEEE Aerospace Conference 202

Probabilistic Principal Component Analysis Applied To Voice Conversion

Abstract-In our model for voice conversion, we represent the joint probabilistic acoustic space of the source and target speakers with a mixture of Probabilistic Principal Component Analyzers (PPCAs). We present a finer resolution of options to the user of the voice conversion system than traditional Gaussian Mixture Model based conversion. Objective experiments demonstrate that the dimension of the PPCA directly impacts resulting objective performance but saves both time and memory complexity. Subjective tests imply that incremental removal of information does not affect the listener perceptually. Thus, the end user can select with more freedom how well the system should perform

Autonomous Rendezvous with Non-cooperative Target Objects with Swarm Chasers and Observers

Space debris is on the rise due to the increasing demand for spacecraft for com-munication, navigation, and other applications. The Space Surveillance Network (SSN) tracks over 27,000 large pieces of debris and estimates the number of small, un-trackable fragments at over 1,00,000. To control the growth of debris, the for-mation of further debris must be reduced. Some solutions include deorbiting larger non-cooperative resident space objects (RSOs) or servicing satellites in or-bit. Both require rendezvous with RSOs, and the scale of the problem calls for autonomous missions. This paper introduces the Multipurpose Autonomous Ren-dezvous Vision-Integrated Navigation system (MARVIN) developed and tested at the ORION Facility at Florida Institution of Technology. MARVIN consists of two sub-systems: a machine vision-aided navigation system and an artificial po-tential field (APF) guidance algorithm which work together to command a swarm of chasers to safely rendezvous with the RSO. We present the MARVIN architec-ture and hardware-in-the-loop experiments demonstrating autonomous, collabo-rative swarm satellite operations successfully guiding three drones to rendezvous with a physical mockup of a non-cooperative satellite in motion.Comment: Presented at AAS/AIAA Spaceflight Mechanics Meeting 2023, 17 pages, 9 figures, 3 table