Guidance algorithms for a free-flying space robot

Robotics is a promising technology for assembly, servicing, and maintenance of platforms in space. Several aspects of planning and guidance for telesupervised and fully autonomous robotic servicers are investigated. Guidance algorithms for proximity operation of a free flyer are described. Numeric trajectory optimization is combined with artificial intelligence based obstacle avoidance. An initial algorithm and the results of its simulating platform servicing scenario are discussed. A second algorithm experiment is then proposed

Potential Clinical Roles for Metabolic Imaging with Hyperpolarized [1-(13)C]Pyruvate.

Work in KMB’s laboratory is supported by a Cancer Research UK Programme grant (17242) and the CRUK-EPSRC Imaging Centre in Cambridge and Manchester (16465). Clinical studies are funded by a Strategic Award from the Wellcome Trust (095962). E.M.S. was a recipient of a fellowship from the European Union Seventh Framework Programme (FP7/2007-2013) under the Marie Curie Initial Training Network METAFLUX (project number 264780). E.M.S. also acknowledges the educational support of the Programme for Advanced Medical Education from Calouste Gulbenkian Foundation, Champalimaud Foundation, Ministerio de Saude and Fundacao para a Ciencia e Tecnologia, Portugal.This is the final version of the article. It first appeared from Frontiers via http://dx.doi.org/10.3389/fonc.2016.0005

The Optical Polarization and Warm Absorber in IRAS 17020+4544

We report the detection of ionized absorption in the ASCA spectrum of the narrow-line Seyfert 1 galaxy IRAS 17020+4544. Subsequent optical spectropolarimetry revealed high polarization increasing from 3% in the red to 5% in the blue, indicating electron or dust scattering as a likely origin. The broad emission line H$\alpha$ is somewhat less polarized than the continuum, supporting a location of the polarizing material within the AGN. The Balmer line decrement and reddened optical spectrum support the presence of a dusty warm absorber in this object. We compared the broad band optical polarization and ionized X-ray absorption of a collection of Seyfert 1 and 1.5 galaxies, excluding classes of objects that are likely to have significant neutral X-ray absorption. Warm absorber objects are generally more likely to have high optical polarization than objects with no detected ionized absorption. This result lends additional support to the idea that the warm absorber is associated with dust and implies either that dust transmission is responsible for at least part of the polarization or that the polarization is revealed because of the dimming of the optical spectrum. Spectropolarimetry of Seyfert 1s generally locates the scattering material inside the narrow-line region and often close to or within the broad line region, consistent with estimates of the location of the dusty warm absorber.Comment: 11 pages using (AASTeX) aaspp4.sty and 3 Postscript figures. Accepted for publication in Astrophysical Journal Letter

Jet directions in Seyfert galaxies: B and I imaging data

We present the results of broad-band B and I imaging observations for a sample of 88 Seyfert galaxies (29 Seyfert 1's and 59 Seyfert 2's), selected from a mostly isotropic property, the flux at 60$\mu$m. We also present the B and I imaging results for an additional sample of 20 Seyfert galaxies (7 Seyfert 1's and 13 Seyfert 2's), selected from the literature and known to have extended radio emission. The I band images are fitted with ellipses to determine the position angle and ellipticity of the host galaxy major axis. This information will be used in a future paper, combined with information from radio observations, to study the orientation of radio jets relative to the plane of their host galaxies (Kinney et al. 2000). Here we present surface brightness profiles and magnitudes in the B and I bands, as well as mean ellipticities and major axis position angles.Comment: To appear in The Astrophysical Journal Supplement Series, June 2000. 48 pages, 7 tables, 19 gif and 11 postscript figures. Better quality figures can be obtained with the autho

Direct enhancement of nuclear singlet order by dynamic nuclear polarization

Hyperpolarized singlet order is available immediately after dissolution DNP, avoiding need for additional preparation steps. We demonstrate this procedure on a sample of [1,2–13C2]pyruvic aci

Imaging metabolism with hyperpolarized (13)C-labeled cell substrates.

Non-invasive (13)C magnetic resonance spectroscopy measurements of the uptake and subsequent metabolism of (13)C-labeled substrates is a powerful method for studying metabolic fluxes in vivo. However, the technique has been hampered by a lack of sensitivity, which has limited both the spatial and temporal resolution. The introduction of dissolution dynamic nuclear polarization in 2003, which by radically enhancing the nuclear spin polarization of (13)C nuclei in solution can increase their sensitivity to detection by more than 10(4)-fold, revolutionized the study of metabolism using magnetic resonance, with temporal and spatial resolutions in the seconds and millimeter ranges, respectively. The principal limitation of the technique is the short half-life of the polarization, which at ∼20-30 s in vivo limits studies to relatively fast metabolic reactions. Nevertheless, pre-clinical studies with a variety of different substrates have demonstrated the potential of the method to provide new insights into tissue metabolism and have paved the way for the first clinical trial of the technique in prostate cancer. The technique now stands on the threshold of more general clinical translation. I consider here what the clinical applications might be, which are the substrates that most likely will be used, how will we analyze the resulting kinetic data, and how we might further increase the levels of polarization and extend polarization lifetime.The work in KMB’s laboratory on imaging metabolism with hyperpolarized 13C-labeled cell substrates is currently sup-ported by grants from Cancer Research UK (17242, 16465), a Wellcome Trust Strategic Award (095962) and a Marie Curie Initial Training Network (EUROPOL).This is the author accepted manuscript. The final version is available from the American Chemical Society via http://dx.doi.org/10.1021/jacs.5b0330

Radiological Hazards of Iodine-131 Therapy

Once iodine-131 is administered to a patient undergoing therapy, the individual becomes a significant source of radiation exposure to attending staff and other patients. The patient also becomes a source of radioactive contamination since much of the administered radioiodine is gradually eliminated via urinary excretion, exhaled air, and perspiration. Duke University Medical Center uses iodine-131 for three different types of cancer treatments: sodium iodide for thyroid carcinoma, monoclonal antibodies for neoplastic meningitis, and metaiodobenzylguanidine (MiBG) for neuroendocrine tumors. The primary focus of this study was to assess the radiological hazards to the medical staff attending these isolated patients and to members of the general public near the patient rooms. In addition, data from this study were used to design special rooms to house patients undergoing radioiodine therapy. The amount of radioiodine administered to the 17 patients in this study ranged from 2.2 GBq (60 mCi) to 11.2 GBq (303 mCi). Exposure rates were measured using an ion chamber at several locations within patient rooms as well as in the hallway and accessible adjacent rooms. Measurements taken within patient rooms ranged from 4.1 x 10[-8] C kg[-1] hr[-1] (0.16 mR hr[-1]) to 1.7 x 10[-5] C kg[-1] hr[-1] (67 mR hr[-1]). Exposure rates ranged from 8.3 x 10[-9] C kg[-1] hr[-1] (0.032 mR hr[-1]) to 4.1 x 10[-7] C kg[-1] hr[-1] (1.6 mR hr[-1]) in the hallways and accessible adjacent rooms. Thermoluminescent dosimeters (TLDs) mounted on the walls, floor, and ceiling of patient rooms were used to determine accumulated dose equivalents for the duration of the patient treatments. The TLD results ranged from 0.20 mSv (20 mrem) to 19.5 mSv (1,950 mrem). Using a portable GM detector, contamination surveys were performed in patient rooms after the patients were discharged from the hospital. Detected contamination levels ranged from 100 c min[-1] to 240,000 c min[-1]. Air sampling was also performed to determine the concentration of radioiodine in the air and to evaluate the necessity for "negative pressure" patient therapy rooms. Exposure rate measurements and dose equivalent measurements suggest that a potential hazard exists for both the attending medical staff and the general public. Dedicating two new lead lined rooms for iodine-131 therapies would greatly reduce hazards to the general public as well as ease the patient room decontamination process for the radiation safety staff. Air sampling results proved to be inconclusive since activity was seen throughout the air sampling units.Master of Science in Public Healt

Health of Philippine Emigrants Study (HoPES): study design and rationale.

BackgroundImmigrants to the United States are usually healthier than their U.S.-born counterparts, yet the health of immigrants declines with duration of stay in the U.S. This pattern is often seen for numerous health problems such as obesity, and is usually attributed to acculturation (the adoption of "American" behaviors and norms). However, an alternative explanation is secular trends, given that rates of obesity have been rising globally. Few studies of immigrants are designed to distinguish the effects of acculturation versus secular trends, in part because most studies of immigrants are cross-sectional, lack baseline data prior to migration, and do not have a comparison group of non-migrants in the country of origin. This paper describes the Health of Philippine Emigrants Study (HoPES), a study designed to address many of these limitations.MethodsHoPES is a dual-cohort, longitudinal, transnational study. The first cohort consisted of Filipinos migrating to the United States (n = 832). The second cohort consisted of non-migrant Filipinos who planned to remain in the Philippines (n = 805). Baseline data were collected from both cohorts in 2017 in the Philippines, with follow-up data collection planned over 3 years in either the U.S. for the migrant cohort or the Philippines for the non-migrant cohort. At baseline, interviewers administered semi-structured questionnaires that assessed demographic characteristics, diet, physical activity, stress, and immigration experiences. Interviewers also measured weight, height, waist and hip circumferences, blood pressure, and collected dried blood spot samples.DiscussionMigrants enrolled in the study appear to be representative of recent Filipino migrants to the U.S. Additionally, migrant and non-migrant study participants are comparable on several characteristics that we attempted to balance at baseline, including age, gender, and education. HoPES is a unique study that approximates a natural experiment from which to study the effects of immigration on obesity and other health problems. A number of innovative methodological strategies were pursued to expand the boundaries of current immigrant health research. Key to accomplishing this research was investment in building collaborative relationships with stakeholders across the U.S. and the Philippines with shared interest in the health of migrants