Simultaneous Exoplanet Characterization and deep wide-field imaging with a diffractive pupil telescope

High-precision astrometry can identify exoplanets and measure their orbits and masses, while coronagraphic imaging enables detailed characterization of their physical properties and atmospheric compositions through spectroscopy. In a previous paper, we showed that a diffractive pupil telescope (DPT) in space can enable sub-microarcsecond accuracy astrometric measurements from wide-field images by creating faint but sharp diffraction spikes around the bright target star. The DPT allows simultaneous astrometric measurement and coronagraphic imaging, and we discuss and quantify in this paper the scientific benefits of this combination for exoplanet science investigations: identification of exoplanets with increased sensitivity and robustness, and ability to measure planetary masses to high accuracy. We show how using both measurements to identify planets and measure their masses offers greater sensitivity and provides more reliable measurements than possible with separate missions, and therefore results in a large gain in mission efficiency. The combined measurements reliably identify potentially habitable planets in multiple systems with a few observations, while astrometry or imaging alone would require many measurements over a long time baseline. In addition, the combined measurement allows direct determination of stellar masses to percent-level accuracy, using planets as test particles. We also show that the DPT maintains the full sensitivity of the telescope for deep wide-field imaging, and is therefore compatible with simultaneous scientific observations unrelated to exoplanets. We conclude that astrometry, coronagraphy, and deep wide-field imaging can be performed simultaneously on a single telescope without significant negative impact on the performance of any of the three techniques.Comment: 15 pages, 6 figures. This second paper, following the paper describing the diffractive pupil telescope (DPT) astrometric technique, shows how simultaneous astrometry and coronagraphy observations, enabled by the DPT concept, constrain the orbital parameters and mass of exoplanet

Telescope to Observe Planetary Systems (TOPS): a high throughput 1.2-m visible telescope with a small inner working angle

The Telescope to Observe Planetary Systems (TOPS) is a proposed space mission to image in the visible (0.4-0.9 micron) planetary systems of nearby stars simultaneously in 16 spectral bands (resolution R~20). For the ~10 most favorable stars, it will have the sensitivity to discover 2 R_E rocky planets within habitable zones and characterize their surfaces or atmospheres through spectrophotometry. Many more massive planets and debris discs will be imaged and characterized for the first time. With a 1.2m visible telescope, the proposed mission achieves its power by exploiting the most efficient and robust coronagraphic and wavefront control techniques. The Phase-Induced Amplitude Apodization (PIAA) coronagraph used by TOPS allows planet detection at 2 lambda/d with nearly 100% throughput and preserves the telescope angular resolution. An efficient focal plane wavefront sensing scheme accurately measures wavefront aberrations which are fed back to the telescope active primary mirror. Fine wavefront control is also performed independently in each of 4 spectral channels, resulting in a system that is robust to wavefront chromaticity.Comment: 12 pages, SPIE conference proceeding, May 2006, Orlando, Florid

TOPS: a small space telescope using phase induced-amplitude apodization (PIAA) to image rocky and giant exo-planets

The Telescope to Observe Planetary Systems (TOPS) is a proposed space mission to image planetary systems of nearby stars simultaneously in a few wide spectral bands covering the visible light (0.4-0.9 μm). It achieves its power by combining a high accuracy wavefront control system with a highly efficient Phase-Induced Amplitude Apodization (PIAA) coronagraph which provides strong suppression very close to the star (within 2 λ/D). The PIAA coronagraphic technique opens the possibility of imaging Earthlike planets in visible light with a smaller telescope than previously supposed. If sized at 1.2-m, TOPS would image and characterize many Jupiter-sized planets, and discover 2 RE rocky planets within habitable zones of the ≈10 most favorable stars. With a larger 2-m aperture, TOPS would have the sensitivity to reveal Earth-like planets in the habitable zone around ≈20 stars, and to characterize any found with low resolution spectroscopy. Unless the occurrence of Earth-like planets is very low (η⊕ <~ 0.2), a useful fraction of the TPF-C scientific program would be possible with aperture much smaller than the baselined 8 by 3.5m for TPF, with its more conventional coronagraph. An ongoing laboratory experiment has successfully demonstrated high contrast coronagraphic imaging within 2 λ/d with the PIAA coronagraph / focal plane wavefront sensing scheme envisioned for TOPS

Problems and needs for improving primary care of osteoarthritis patients: the views of patients, general practitioners and practice nurses

BACKGROUND: Osteoarthritis (OA) is highly prevalent and has substantial impact on quality of life as well as on healthcare costs. The general practitioner (GP) often is the first care provider for patients with this chronic disease. The aim of this study was to identify health care needs of patients with OA and to reveal possible obstacles for improvements in primary care management of OA patients. METHODS: We performed semi-structured interviews with a stratified sample of 20 patients, 20 GPs and 20 practice nurses. RESULTS: Diagnosing OA posed no major problem, but during the course of OA, GPs found it difficult to distinguish between complaints resulting from the affection of the joints and complaints related to a concomitant depression. Patients felt to be well informed about the degenerative nature of the disease and possible side effects of medications, but they lacked information on individual consequences of the disease. Therefore, the most important concerns of many patients were pain and fear of disability which they felt to be addressed by GPs only marginally. Regarding pain treatment, physicians and patients had an ambivalent attitude towards NSAIDs and opiates. Therefore, pain treatment was not performed according to prevailing guidelines. GPs felt frustrated about the impact of counselling regarding life style changes but on the other hand admitted to have no systematic approach to it. Patients stated to be aware of the impact of life style on OA but lacked detailed information e.g. on how to exercise. Several suggestions were made concerning improvement. CONCLUSION: GPs should focus more on disability and pain and on giving information about treatment since these topics are inadequately addressed. Advanced approaches are needed to increase GPs impact on patients' life style. Being aware of the problem of labelling patients as chronically ill, a more proactive, patient-centred care is needed

Rationale, design and conduct of a comprehensive evaluation of a primary care based intervention to improve the quality of life of osteoarthritis patients. The PraxArt-project: a cluster randomized controlled trial [ISRCTN87252339]

BACKGROUND: Osteoarthritis (OA) has a high prevalence in primary care. Conservative, guideline orientated approaches aiming at improving pain treatment and increasing physical activity, have been proven to be effective in several contexts outside the primary care setting, as for instance the Arthritis Self management Programs (ASMPs). But it remains unclear if these comprehensive evidence based approaches can improve patients' quality of life if they are provided in a primary care setting. METHODS/DESIGN: PraxArt is a cluster randomised controlled trial with GPs as the unit of randomisation. The aim of the study is to evaluate the impact of a comprehensive evidence based medical education of GPs on individual care and patients' quality of life. 75 GPs were randomised either to intervention group I or II or to a control group. Each GP will include 15 patients suffering from osteoarthritis according to the criteria of ACR. In intervention group I GPs will receive medical education and patient education leaflets including a physical exercise program. In intervention group II the same is provided, but in addition a practice nurse will be trained to monitor via monthly telephone calls adherence to GPs prescriptions and advices and ask about increasing pain and possible side effects of medication. In the control group no intervention will be applied at all. Main outcome measurement for patients' QoL is the GERMAN-AIMS2-SF questionnaire. In addition data about patients' satisfaction (using a modified EUROPEP-tool), medication, health care utilization, comorbidity, physical activity and depression (using PHQ-9) will be retrieved. Measurements (pre data collection) will take place in months I-III, starting in June 2005. Post data collection will be performed after 6 months. DISCUSSION: Despite the high prevalence and increasing incidence, comprehensive and evidence based treatment approaches for OA in a primary care setting are neither established nor evaluated in Germany. If the evaluation of the presented approach reveals a clear benefit it is planned to provide this GP-centred interventions on a much larger scale

Jurisprudences of jurisdiction: matters of public authority

This essay examines a number of jurisdictional engagements that point to difficulties in joining or separating relations between public authority, jurisprudences of jurisdiction and the writing of jurisprudence

A model for homeopathic remedy effects: low dose nanoparticles, allostatic cross-adaptation, and time-dependent sensitization in a complex adaptive system

BACKGROUND: This paper proposes a novel model for homeopathic remedy action on living systems. Research indicates that homeopathic remedies (a) contain measurable source and silica nanoparticles heterogeneously dispersed in colloidal solution; (b) act by modulating biological function of the allostatic stress response network (c) evoke biphasic actions on living systems via organism-dependent adaptive and endogenously amplified effects; (d) improve systemic resilience. DISCUSSION: The proposed active components of homeopathic remedies are nanoparticles of source substance in water-based colloidal solution, not bulk-form drugs. Nanoparticles have unique biological and physico-chemical properties, including increased catalytic reactivity, protein and DNA adsorption, bioavailability, dose-sparing, electromagnetic, and quantum effects different from bulk-form materials. Trituration and/or liquid succussions during classical remedy preparation create “top-down” nanostructures. Plants can biosynthesize remedy-templated silica nanostructures. Nanoparticles stimulate hormesis, a beneficial low-dose adaptive response. Homeopathic remedies prescribed in low doses spaced intermittently over time act as biological signals that stimulate the organism’s allostatic biological stress response network, evoking nonlinear modulatory, self-organizing change. Potential mechanisms include time-dependent sensitization (TDS), a type of adaptive plasticity/metaplasticity involving progressive amplification of host responses, which reverse direction and oscillate at physiological limits. To mobilize hormesis and TDS, the remedy must be appraised as a salient, but low level, novel threat, stressor, or homeostatic disruption for the whole organism. Silica nanoparticles adsorb remedy source and amplify effects. Properly-timed remedy dosing elicits disease-primed compensatory reversal in direction of maladaptive dynamics of the allostatic network, thus promoting resilience and recovery from disease. SUMMARY: Homeopathic remedies are proposed as source nanoparticles that mobilize hormesis and time-dependent sensitization via non-pharmacological effects on specific biological adaptive and amplification mechanisms. The nanoparticle nature of remedies would distinguish them from conventional bulk drugs in structure, morphology, and functional properties. Outcomes would depend upon the ability of the organism to respond to the remedy as a novel stressor or heterotypic biological threat, initiating reversals of cumulative, cross-adapted biological maladaptations underlying disease in the allostatic stress response network. Systemic resilience would improve. This model provides a foundation for theory-driven research on the role of nanomaterials in living systems, mechanisms of homeopathic remedy actions and translational uses in nanomedicine

MILLIMETER-WAVE INVESTIGATION OF EVOLVED PLANETARY NEBULAE CHEMISTRY

Author Institution: Steward Observatory, University of Arizona, 933 N. Cherry Avenue, Tucson, AZ 85721We report the detection of C$_2$H and c-C$_3$H$_2$ in a number of evolved planetary nebulae. C$_2$H has been detected in NGC 6720 (Ring Nebula), NGC 7293 (Helix Nebula), and NGC 6781 via the two hyperfine components of the N=1$\rightarrow$0, J=3/2$\rightarrow$1/2 transition near 87 GHz, as well as in M4-9 via the two spin-rotation components of the N=3$\rightarrow$2 transition near 262 Ghz. In the Helix Nebula, the J$_{Ka,Kc}$=1$_{2,0}\rightarrow$0$_{1,0}$ and 10$_{1,0}\rightarrow$9$_{2,0}$ transitions of c-C$_3$H$_2$ have been detected near 85 and 105 GHz, respectively. These detections suggest that the molecular complexity in evolved planetary nebulae is higher than previously thought. It appears that as planetary nebulae expand and age, many-atom molecules may be shielded from UV dissociation because they are contained in dense knots of gas and dust. Further investigation of the gas-phase chemistry of evolved planetary nebulae is being conducted using the Arizona Radio Observatory telescopes