Two Earth-sized planets orbiting Kepler-20

Since the discovery of the first extrasolar giant planets around Sun-like stars, evolving observational capabilities have brought us closer to the detection of true Earth analogues. The size of an exoplanet can be determined when it periodically passes in front of (transits) its parent star, causing a decrease in starlight proportional to its radius. The smallest exoplanet hitherto discovered has a radius 1.42 times that of the Earth's radius (R Earth), and hence has 2.9 times its volume. Here we report the discovery of two planets, one Earth-sized (1.03R Earth) and the other smaller than the Earth (0.87R Earth), orbiting the star Kepler-20, which is already known to host three other, larger, transiting planets. The gravitational pull of the new planets on the parent star is too small to measure with current instrumentation. We apply a statistical method to show that the likelihood of the planetary interpretation of the transit signals is more than three orders of magnitude larger than that of the alternative hypothesis that the signals result from an eclipsing binary star. Theoretical considerations imply that these planets are rocky, with a composition of iron and silicate. The outer planet could have developed a thick water vapour atmosphere.Comment: Letter to Nature; Received 8 November; accepted 13 December 2011; Published online 20 December 201

Using molecular data for epidemiological inference: assessing the prevalence of Trypanosoma brucei rhodesiense in Tsetse in Serengeti, Tanzania

Background: Measuring the prevalence of transmissible Trypanosoma brucei rhodesiense in tsetse populations is essential for understanding transmission dynamics, assessing human disease risk and monitoring spatio-temporal trends and the impact of control interventions. Although an important epidemiological variable, identifying flies which carry transmissible infections is difficult, with challenges including low prevalence, presence of other trypanosome species in the same fly, and concurrent detection of immature non-transmissible infections. Diagnostic tests to measure the prevalence of T. b. rhodesiense in tsetse are applied and interpreted inconsistently, and discrepancies between studies suggest this value is not consistently estimated even to within an order of magnitude. Methodology/Principal Findings: Three approaches were used to estimate the prevalence of transmissible Trypanosoma brucei s.l. and T. b. rhodesiense in Glossina swynnertoni and G. pallidipes in Serengeti National Park, Tanzania: (i) dissection/microscopy; (ii) PCR on infected tsetse midguts; and (iii) inference from a mathematical model. Using dissection/microscopy the prevalence of transmissible T. brucei s.l. was 0% (95% CI 0–0.085) for G. swynnertoni and 0% (0–0.18) G. pallidipes; using PCR the prevalence of transmissible T. b. rhodesiense was 0.010% (0–0.054) and 0.0089% (0–0.059) respectively, and by model inference 0.0064% and 0.00085% respectively. Conclusions/Significance: The zero prevalence result by dissection/microscopy (likely really greater than zero given the results of other approaches) is not unusual by this technique, often ascribed to poor sensitivity. The application of additional techniques confirmed the very low prevalence of T. brucei suggesting the zero prevalence result was attributable to insufficient sample size (despite examination of 6000 tsetse). Given the prohibitively high sample sizes required to obtain meaningful results by dissection/microscopy, PCR-based approaches offer the current best option for assessing trypanosome prevalence in tsetse but inconsistencies in relating PCR results to transmissibility highlight the need for a consensus approach to generate meaningful and comparable data

MICE: The muon ionization cooling experiment. Step I: First measurement of emittance with particle physics detectors

Copyright @ 2011 APSThe Muon Ionization Cooling Experiment (MICE) is a strategic R&D project intended to demonstrate the only practical solution to providing high brilliance beams necessary for a neutrino factory or muon collider. MICE is under development at the Rutherford Appleton Laboratory (RAL) in the United Kingdom. It comprises a dedicated beamline to generate a range of input muon emittances and momenta, with time-of-flight and Cherenkov detectors to ensure a pure muon beam. The emittance of the incoming beam will be measured in the upstream magnetic spectrometer with a scintillating fiber tracker. A cooling cell will then follow, alternating energy loss in Liquid Hydrogen (LH2) absorbers to RF cavity acceleration. A second spectrometer, identical to the first, and a second muon identification system will measure the outgoing emittance. In the 2010 run at RAL the muon beamline and most detectors were fully commissioned and a first measurement of the emittance of the muon beam with particle physics (time-of-flight) detectors was performed. The analysis of these data was recently completed and is discussed in this paper. Future steps for MICE, where beam emittance and emittance reduction (cooling) are to be measured with greater accuracy, are also presented.This work was supported by NSF grant PHY-0842798

Radiofrequency-based treatment in therapy-related clinical practice – a narrative review. Part I : acute conditions

This is an Accepted Manuscript of an article published by Taylor & Francis Group in Physical Therapy Reviews on 24 June 2015, available online at: https://www.tandfonline.com/doi/full/10.1179/1743288X15Y.0000000016Background: Radiofrequency electromagnetic field (RFEMF or simply RF)-based electrophysical agents (EPAs) have been employed in therapy-related clinical practice for several decades. They are used to reduce pain and inflammation and enhance tissue healing. Although these agents have generally become less popular in contemporary therapy practice, surveys have shown that some of these modalities are still reasonably widely used. Objective: To review the evidence for the use of non-invasive low frequency RFs (30 kHz–30 MHz) in therapy-related clinical practice. Major findings: All peer reviewed therapy-related clinical studies published in English and concerning low frequency RF were sought. Identified literature was divided into acute and chronic segments based on their clinical area and analysed to assess the volume and scope of current evidence. The studies on acute conditions were reviewed in detail for this paper. One hundred twenty clinical studies were identified, of which 30 related to acute conditions. The majority of studies employed Pulsed Shortwave Therapy (PSWT). Twenty-two studies out of 30 were related to conditions of pain and inflammation, seven to tissue healing and one to acute pneumothorax. No studies were identified on frequencies other than shortwave. Conclusions: Evidence for and against RF-based therapy is available. There is reasonable evidence in support of PSWT to alleviate postoperative pain and promote postoperative wound healing. Evidence for other acute conditions is sparse and conflicting. A general lack of research emphasis in the non-shortwave RF band is evident, with studies on acute conditions almost non-existent. Further and wider research in this area is warranted.Peer reviewe

The ACA training programme to improve communication between general practitioners and their palliative care patients: development and applicability

<p>Abstract</p> <p>We describe the development of a new training programme on GP-patient communication in palliative care, and the applicability to GPs and GP Trainees. This ‘ACA training programme’ focuses on <b> <it>A</it> </b><it>vailability</it> of the GP for the patient, <b> <it>C</it> </b><it>urrent issues</it> that should be raised by the GP, and <b> <it>A</it> </b><it>nticipating</it> various scenarios. Evaluation results indicate the ACA training programme to be applicable to GPs and GP Trainees. The ACA checklist was appreciated by GPs as useful both in practice and as a learning tool, whereas GP Trainees mainly appreciated the list for use in practice.</p

Alignment of the stellar spin with the orbits of a three-planet system

The Sun’s equator and the planets’ orbital planes are nearly aligned, which is presumably a consequence of their formation from a single spinning gaseous disk. For exoplanetary systems this well-aligned configuration is not guaranteed: dynamical interactions may tilt planetary orbits, or stars may be misaligned with the protoplanetary disk through chaotic accretion1 , magnetic interactions[superscript 2] or torques from neighbouring stars. Indeed, isolated ‘hot Jupiters’ are often misaligned and even orbiting retrograde[superscript 3, 4]. Here we report an analysis of transits of planets over starspots[superscript 5, 6, 7] on the Sun-like star Kepler-30 (ref. 8), and show that the orbits of its three planets are aligned with the stellar equator. Furthermore, the orbits are aligned with one another to within a few degrees. This configuration is similar to that of our Solar System, and contrasts with the isolated hot Jupiters. The orderly alignment seen in the Kepler-30 system suggests that high obliquities are confined to systems that experienced disruptive dynamical interactions. Should this be corroborated by observations of other coplanar multi-planet systems, then star–disk misalignments would be ruled out as the explanation for the high obliquities of hot Jupiters, and dynamical interactions would be implicated as the origin of hot Jupiters.United States. National Aeronautics and Space Administration (Science MissionDirectorate

Moral Distress Amongst American Physician Trainees Regarding Futile Treatments at the End of Life: A Qualitative Study.

BACKGROUND: Ethical challenges are common in end of life care; the uncertainty of prognosis and the ethically permissible boundaries of treatment create confusion and conflict about the balance between benefits and burdens experienced by patients. OBJECTIVE: We asked physician trainees in internal medicine how they reacted and responded to ethical challenges arising in the context of perceived futile treatments at the end of life and how these challenges contribute to moral distress. DESIGN: Semi-structured in-depth qualitative interviews. PARTICIPANTS: Twenty-two internal medicine residents and fellows across three American academic medical centers. APPROACH: This study uses systematic qualitative methods of data gathering, analysis and interpretation. KEY RESULTS: Physician trainees experienced significant moral distress when they felt obligated to provide treatments at or near the end of life that they believed to be futile. Some trainees developed detached and dehumanizing attitudes towards patients as a coping mechanism, which may contribute to a loss of empathy. Successful coping strategies included formal and informal conversations with colleagues and superiors about the emotional and ethical challenges of providing care at the end of life. CONCLUSIONS: Moral distress amongst physician trainees may occur when they feel obligated to provide treatments at the end of life that they believe to be futile or harmful.This study was funded by the Health Resources and Service Administration T32 HP10025-20 Training Grant, the Gates Cambridge Scholarship, Society of General Internal Medicine Founders Grant, and the Ho-Chiang Palliative Care Research Fellowship at the Johns Hopkins School of Medicine.This is the author accepted manuscript. The final version is available from Springer via http://dx.doi.org/10.1007/s11606-015-3505-

Correlations of EGFR mutations and increases in EGFR and HER2 copy number to gefitinib response in a retrospective analysis of lung cancer patients

<p>Abstract</p> <p>Background</p> <p>Gefitinib, a small molecule tyrosine kinase inhibitor of the Epidermal Growth Factor Receptor (<it>EGFR</it>), has shown limited efficacy in the treatment of lung cancer. Recognized clinical predictors of response to this drug, specifically female, non-smoker, Asian descent, and adenocarcinoma, together suggest a genetic basis for drug response. Recent studies have addressed the relationship between response and either sequence mutations or increased copy number of specific receptor tyrosine kinases. We set out to examine the relationship between response and the molecular status of two such kinases, <it>EGFR </it>and <it>HER2</it>, in 39 patients treated with gefitinib at the BC Cancer Agency.</p> <p>Methods</p> <p>Archival patient material was reviewed by a pathologist and malignant cells were selectively isolated by laser microdissection or manual recovery of cells from microscope slides. Genomic DNA was extracted from 37 such patient samples and exons 18–24, coding for the tyrosine kinase domain of <it>EGFR</it>, were amplified by PCR and sequenced. <it>EGFR </it>and <it>HER2 </it>copy number status were also assessed using FISH in 26 samples. Correlations between molecular features and drug response were assessed using the two-sided Fisher's exact test.</p> <p>Results</p> <p>Mutations previously correlated with response were detected in five tumours, four with exon 19 deletions and one with an exon 21 missense L858R point mutation. Increased gene copy number was observed in thirteen tumours, seven with <it>EGFR </it>amplification, three with <it>HER2 </it>amplification, and three with amplification of both genes. In our study cohort, a correlation was not observed between response and <it>EGFR </it>mutations (exon 19 deletion p = 0.0889, we observed a single exon 21 mutation in a non-responder) or increases in <it>EGFR </it>or <it>HER2 </it>copy number (p = 0.552 and 0.437, respectively).</p> <p>Conclusion</p> <p>Neither mutation of <it>EGFR </it>nor increased copy number of <it>EGFR </it>or <it>HER2 </it>was diagnostic of response to gefitinib in this cohort. However, validation of these features in a larger sample set is appropriate. Identification of additional predictive biomarkers beyond <it>EGFR </it>status may be necessary to accurately predict treatment outcome.</p

Potential impact of invasive alien species on ecosystem services provided by a tropical forested ecosystem: a case study from Montserrat

Local stakeholders at the important but vulnerable Centre Hills on Montserrat consider that the continued presence of feral livestock (particularly goats and pigs) may lead to widespread replacement of the reserve’s native vegetation by invasive alien trees (Java plum and guava), and consequent negative impacts on native animal species. Since 2009, a hunting programme to control the feral livestock has been in operation. However long-term funding is not assured. Here, we estimate the effect of feral livestock control on ecosystem services provided by the forest to evaluate whether the biodiversity conservation rationale for continuation of the control programme is supported by an economic case. A new practical tool (Toolkit for Ecosystem Service Site-based Assessment) was employed to measure and compare ecosystem service provision between two states of the reserve (i.e. presence and absence of feral livestock control) to estimate the net consequences of the hunting programme on ecosystem services provided by the forest. Based on this we estimate that cessation of feral livestock management would substantially reduce the net benefits provided by the site, including a 46 % reduction in nature-based tourism (from $419,000 to$228,000) and 36 % reduction in harvested wild meat (from $205,000 to$132,000). The overall net benefit generated from annual ecosystem service flows associated with livestock control in thereserve, minus the management cost, was $214,000 per year. We conclude that continued feral livestock control is important for maintaining the current level of ecosystem services provided by the reserve