Exactly Sparse Delayed-State Filters for View-Based SLAM

This paper reports the novel insight that the simultaneous localization and mapping (SLAM) information matrix is exactly sparse in a delayed-state framework. Such a framework is used in view-based representations of the environment that rely upon scan-matching raw sensor data to obtain virtual observations of robot motion with respect to a place it has previously been. The exact sparseness of the delayed-state information matrix is in contrast to other recent feature-based SLAM information algorithms, such as sparse extended information filter or thin junction-tree filter, since these methods have to make approximations in order to force the feature-based SLAM information matrix to be sparse. The benefit of the exact sparsity of the delayed-state framework is that it allows one to take advantage of the information space parameterization without incurring any sparse approximation error. Therefore, it can produce equivalent results to the full-covariance solution. The approach is validated experimentally using monocular imagery for two datasets: a test-tank experiment with ground truth, and a remotely operated vehicle survey of the RMS Titanic     

Microengineered dynamometer for microfan thrust measurement

The fabrication, development and thrust testing of a microengineered three-beam suspended structure manufactured in nickel is described. The structure is intended to be used as a support for axial-flow microfans and microturbines. The purpose of the test device is to measure torsional friction drag as a function of thrust force in configurations where microfans have cup-shaped bearings     

Simulating Entrainment and Particle Fluxes in Stratified Estuaries

Settling and entrainment are the dominant processes governing noncohesive particle concentration throughout the water column of salt-wedge estuaries. Determination of the relative contribution of these transport processes is complicated by vertical gradients in turbulence and fluid density. A differential-turbulence column (DTC) was designed to simulate a vertical section of a natural water column. With satisfactory characterization of turbulence dissipation and saltwater entrainment, the DTC facilitates controlled studies of suspended particles under estuarine conditions. The vertical decay of turbulence in the DTC was found to obey standard scaling law relations when the characteristic length scale for turbulence in the apparatus was incorporated. The entrainment rate of a density interface also followed established grid-stirred turbulence scaling laws. These relations were used to model the change in concentration of noncohesive particles above a density interface. Model simulations and experimental data from the DTC were consistent over the range of conditions encountered in natural salt-wedge estuaries. Results suggest that when the ratio of entrainment rate to particle settling velocity is small, sedimentation is the dominant transport process, while entrainment becomes significant as the ratio increases.     

Computer models of Kabul, Afghanistan, medium-wave antennas

Design and implementation of new feed systems for two Russian-built skirted Franklin vertical antennas near Kabul, Afghanistan, were accomplished using moment method techniques. To facilitate re-tuning to new operating frequencies, the original stub-tuned matching network was replaced with a conventional "T" network. The proper settings of the terminating stubs on the lower skirts in order to obtain the desired current distributions were also evaluated by moment method techniques. At the completion of the installation, the measured drive impedances correlated very well with the calculated values, indicating achievement of the desired performance.     

Use of a High-Temperature Integrating Sphere Reflectometer for Surface-Temperature Measurements

The National Institute of Standards and Technology (NIST) has developed a new facility for the characterization of the infrared spectral emissivity of samples between 150 and 1,000°C. For accurate measurement of the sample surface temperatures above 150°C, the system employs a high-temperature reflectometer to obtain the surface temperature of the sample. This technique is especially useful for samples that have significant temperature gradients due to the thermal conductivity of the sample and the heating mechanism used. The sample temperature is obtained through two measurements: (a) an indirect sample emissivity measurement with an integrating sphere reflectometer and (b) a relative radiance measurement (at the same wavelengths as in (a)) of the sample as compared to a blackbody source. The results are combined with a knowledge of the blackbody temperature and Planck’s law to obtain the sample temperature. The reflectometer’s integrating sphere is a custom design that accommodates the sample and heater to allow reflectance measurements at temperature. The sphere measures the hemispherical-near- normal (8°) reflectance factor of the sample compared relative to a previously calibrated room-temperature reference sample. The reflectometer technique of sample temperature measurement is evaluated with several samples of varying reflectance. Temperature results are compared with values simultaneously obtained from embedded thermocouples and temperature-drop calculations using a knowledge of the sample’s thermal conductivity.     

Measurement and structural invariance of parent ratings of ADHD and ODD symptoms across gender for American and Malaysian children.

The purpose of this study was to examine the measurement (configural, metric, scalar, and residual) and structural (factor variance, factor covariance, and factor means) invariance of parent ratings of the attention-deficit/hyperactivity disorder-inattention (ADHD-IN), ADHD-hyperactivity/impulsivity (ADHD-HI), and oppositional defiant disorder (ODD) symptoms as described in the Diagnostic and Statistical Manual of Mental Disorders (4th ed.; American Psychiatric Association, 1994) across boys and girls. In an American pediatric sample (N = 1,015) and a Malaysian elementary school-age sample (N = 928), there was strong support for configural, metric, scalar, residual, factor variance, and covariance invariance across gender within each sample. Both American and Malaysian boys had significantly higher scores on the ADHD-IN and ADHD-HI factor means than did girls, whereas only in the American sample did boys score significantly higher on the ODD factor than did girls. The implications of the results for the study of gender, ethnic, and cultural differences associated with ADHD and ODD are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Partnering Is the Foundation of a Learning Organization

A simple model of an implementation strategy for cultivating a Learning Organization culture is “Transformational Leadership + Group Process = Learning Organization.” This article presents the four key dimensions of Partnering, the Partnering Effectiveness Model, and Principles of Productive Partnering as the basis, or foundation, for following this implementation strategy. Honoring the structure and operating principles of this scientific understanding of Partnering creates a cultural orientation that fosters individual and team learning. Many organizations and their leaders are well intended, yet lack an understanding of the unconscious beliefs, behaviors, and cultural influences that impede learning. Using the implementation process presented, we take a step-by-step approach to systematically exploring what is actually going on now, and how we want things to be. Then, recognizing the need for developing new skills, and change processes, it is a straightforward approach to execute an improvement plan that ensures success.     

Consistent, persistent expression from modified retroviral vectors in murine hematopoietic stem cells

Retroviral vectors based on the Moloney murine leukemia virus (MoMuLV) have shown inconsistent levels and duration of expression as well as a propensity for the acquisition of de novo methylation in vivo. MoMuLV-based vectors are known to contain sequences that are capable of suppressing or preventing expression from the long terminal repeat. Previously, we constructed a series of modified retroviral vectors and showed that they function significantly better than MoMuLV-based vectors in vitro. To test the efficacy of the modified vectors in hematopoietic stem cells in vivo, we examined gene expression and proviral methylation in differentiated hematopoietic colonies formed in the spleens of mice after serial transplantation with transduced bone marrow (2 degreesCFU-S). We found a significant increase in the frequency of expression with our modified vectors (>90% expression in vector DNA containing 2 degreesCFU-S) over the frequency observed with the standard MoMuLV-based vector (28% expression in vector containing 2 degreesCFU-S). Expression from the modified vectors was highly consistent, with expression in >50% of the vector-containing 2 degreesCFU-S from all 20 transplant recipients analyzed, whereas expression from the standard MoMuLV-based vector was inconsistent, with expression in 0-10% of the vector containing 2 degreesCFU-S from 8 recipients and expression in >50% of the vector-containing 2 degreesCFU-S from 4 other recipients. In addition, we established that the modified vectors had a lower level of DNA methylation than the control vector. These findings represent significant advances in the development and evaluation of effective retroviral vectors for application in vivo.     

American Psychological Association Commission on Violence and Youth.

Lists the membership of the commission and discusses its objective of analyzing the roles of perpetrators and victims of violence and the psychosocial consequences of witnessing violent acts and living with the constant threat of violence. The commission is using interdisciplinary expertise to examine the developmental and sustaining factors of violence, as well as frequently targeted groups. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The case for high-dose adjuvant chemotherapy in breast cancer: (I) theoretical considerations

Adjuvant systemic therapy of breast cancer is now a well-established treatment resulting in improved survival. However, the available evidence suggests that it is most unlikely that an individual woman will be cured as a consequence of such treatment. There is, therefore, a pressing need for more effective therapy, particularly for younger women whose degree of axillary nodal involvement indicates a high risk of subsequent relapse. The case for using myelo-ablative chemotherapy for such women is presented in this article. In a subsequent publication we will discuss the clinical data to suggest that such an approach is not only possible with acceptable toxicity, but also could actually offer the increased cure rate sought by clinicians and patients alike.