Removing Orbital Debris with Lasers

Orbital debris in low Earth orbit (LEO) are now sufficiently dense that the use of LEO space is threatened by runaway collisional cascading. A problem predicted more than thirty years ago, the threat from debris larger than about 1 cm demands serious attention. A promising proposed solution uses a high power pulsed laser system on the Earth to make plasma jets on the objects, slowing them slightly, and causing them to re-enter and burn up in the atmosphere. In this paper, we reassess this approach in light of recent advances in low-cost, light-weight modular design for large mirrors, calculations of laser-induced orbit changes and in design of repetitive, multi-kilojoule lasers, that build on inertial fusion research. These advances now suggest that laser orbital debris removal (LODR) is the most cost-effective way to mitigate the debris problem. No other solutions have been proposed that address the whole problem of large and small debris. A LODR system will have multiple uses beyond debris removal. International cooperation will be essential for building and operating such a system.Comment: 37 pages, 15 figures, in preparation for submission to Advances in Space Researc

A Study of a Mini-drift GEM Tracking Detector

A GEM tracking detector with an extended drift region has been studied as part of an effort to develop new tracking detectors for future experiments at RHIC and for the Electron Ion Collider that is being planned for BNL or JLAB. The detector consists of a triple GEM stack with a small drift region that was operated in a mini TPC type configuration. Both the position and arrival time of the charge deposited in the drift region were measured on the readout plane which allowed the reconstruction of a short vector for the track traversing the chamber. The resulting position and angle information from the vector could then be used to improve the position resolution of the detector for larger angle tracks, which deteriorates rapidly with increasing angle for conventional GEM tracking detectors using only charge centroid information. Two types of readout planes were studied. One was a COMPASS style readout plane with 400 micron pitch XY strips and the other consisted of 2x10mm2 chevron pads. The detector was studied in test beams at Fermilab and CERN, along with additional measurements in the lab, in order to determine its position and angular resolution for incident track angles up to 45 degrees. Several algorithms were studied for reconstructing the vector using the position and timing information in order to optimize the position and angular resolution of the detector for the different readout planes. Applications for large angle tracking detectors at RHIC and EIC are also discussed.Comment: Submitted to the IEEE Transactions on Nuclear Scienc

Prevalence and severity of dental caries among American Indian and Alaska Native preschool children

Objectives: To describe the Indian Health Service (IHS) oral health surveillance system and the oral health status of American Indian and Alaska Native (AI/AN) children aged 1‐5 years. Methods: A stratified probability sample of IHS/tribal sites was selected. Children were screened by trained examiners at community‐based locations including medical clinics, Head Start, preschools, kindergarten, and Women, Infants, and Children (WIC). Data collection was limited to the primary dentition and included number of teeth present plus number of teeth with cavitated lesions, restorations, and extracted because of decay. Number of molars with sealants and urgency of need for dental care data were also obtained. Statistical analyses were performed with SAS (SAS Institute Inc., Cary, NC, USA). Sample weights were used to produce population estimates based on selection probabilities. Results: A total of 8,461 AI/AN children 12‐71 months of age were screened at 63 IHS/tribal sites, approximately 7 percent of the estimated IHS user population of the same age. Overall, 54 percent of the children had decay experience, 39 percent had untreated decay, 7 percent had primary molar sealants, 36 percent needed early or urgent dental care, and 6 percent needed urgent dental care. The mean of decayed, missing, or filled teeth was 3.5 (95 percent confidence interval, 3.1‐3.9). The prevalence of decay experience increased with age; 21 percent of 1‐year‐olds and 75 percent of 5‐year‐olds had a history of caries. When stratified by IHS area, there were substantial differences in the oral health of preschool children. Conclusions: The results confirm that in the United States, AI/AN children served by IHS/tribal programs are one of the racial/ethnic groups at highest risk of caries.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/93514/1/j.1752-7325.2012.00331.x.pd

Rapid Molecular Detection Methods for Arboviruses of Livestock of Importance to Northern Europe

Arthropod-borne viruses (arboviruses) have been responsible for some of the most explosive epidemics of emerging infectious diseases over the past decade. Their impact on both human and livestock populations has been dramatic. The early detection either through surveillance or diagnosis of virus will be a critical feature in responding and resolving the emergence of such epidemics in the future. Although some of the most important emerging arboviruses are human pathogens, this paper aims to highlight those diseases that primarily affect livestock, although many are zoonotic and some occasionally cause human mortality. This paper also highlights the molecular detection methods specific to each virus and identifies those emerging diseases for which a rapid detection methods are not yet developed

Autofluorescence lifetime augmented reality as a means for real-time robotic surgery guidance in human patients.

Due to loss of tactile feedback the assessment of tumor margins during robotic surgery is based only on visual inspection, which is neither significantly sensitive nor specific. Here we demonstrate time-resolved fluorescence spectroscopy (TRFS) as a novel technique to complement the visual inspection of oral cancers during transoral robotic surgery (TORS) in real-time and without the need for exogenous contrast agents. TRFS enables identification of cancerous tissue by its distinct autofluorescence signature that is associated with the alteration of tissue structure and biochemical profile. A prototype TRFS instrument was integrated synergistically with the da Vinci Surgical robot and the combined system was validated in swine and human patients. Label-free and real-time assessment and visualization of tissue biochemical features during robotic surgery procedure, as demonstrated here, not only has the potential to improve the intraoperative decision making during TORS but also other robotic procedures without modification of conventional clinical protocols

Pharmacists subjected to disciplinary action: Characteristics and risk factors

Abstract Objective To establish whether there are any characteristics of pharmacists that predict their likelihood of being subjected to disciplinary action. Methods The setting was the Royal Pharmaceutical Society of Great Britain's Disciplinary Committee. One hundred and seventeen pharmacists, all of whom had been referred to the Disciplinary Committee, were matched with a quota sample of 580 pharmacists who had not been subjected to disciplinary action but that matched the disciplined pharmacists on a set of demographic factors (gender, country of residence, year of registration). Frequency analysis and regression analysis were used to compare the two groups of pharmacists in terms of sector of work, ethnicity, age and country of training. Descriptive statistics were also obtained from the disciplined pharmacists to further explore characteristics of disciplinary cases and those pharmacists who undergo them. Key findings While a number of characteristics appeared to increase the likelihood of a pharmacist being referred to the disciplinary committee, only one of these – working in a community pharmacy – was statistically significant. Professional misconduct accounted for a greater proportion of referrals than did clinical malpractice, and approximately one-fifth of pharmacists who went before the Disciplinary Committee had previously been disciplined by the Society. Conclusions This study provides initial evidence of pharmacist characteristics that are associated with an increased risk of being disciplined, based upon the data currently available. It is recommended that follow-up work is carried out using a more extensive dataset in order to confirm the statistical trends identified here. </jats:sec

Laser ablation loading of a surface-electrode ion trap

We demonstrate loading by laser ablation of $^{88}$Sr$^+$ ions into a mm-scale surface-electrode ion trap. The laser used for ablation is a pulsed, frequency-tripled Nd:YAG with pulse energies of 1-10 mJ and durations of 3-5 ns. An additional laser is not required to photoionize the ablated material. The efficiency and lifetime of several candidate materials for the laser ablation target are characterized by measuring the trapped ion fluorescence signal for a number of consecutive loads. Additionally, laser ablation is used to load traps with a trap depth (40 meV) below where electron impact ionization loading is typically successful ($\gtrsim$ 500 meV).Comment: 4 pages, 4 figure

Violent and victimized bodies: sexual violence policy in England and Wales

This paper uses the notion of the body to frame an archaeology of sexual violence policy in England and Wales, applying and developing Pillow’s ideas. It argues that the dominant construction is of sexual violence as an individualized crime, with the solution being for a survivor to report, and with support often instrumentalized in relation to criminal justice objectives. However, criminal justice proceedings can intensify or create further trauma for sexual violence survivors. Furthermore, in addition to criminalizing the violent body and supporting the victimized one, there is a need for policy to produce alternative types of bodies through preventative interventions. Much sexual violence is situated within (hetero) sexual dynamics constructing a masculine aggressor and a feminine body which eventually yields. Prevention must therefore focus on developing embodied boundaries, and narratives at the margins of policy could underpin such efforts