bluuebunny/crossref_metadata_2025 huggingface dataset:
Large-Scale and Flexible Self-Powered Triboelectric Tactile Sensing Array for Sensitive Robot Skin
Authors: Liu Huicong , Ji Zhangping , Xu Hui , Sun Ming , Chen Tao , Sun Lining , Chen Guodong , Wang Zhenhua
Published: November 2017

Advances in flexible and multifunctional electronic devices have enabled the realization of sophisticated skin for robotics applications. In this paper, a large-scale, flexible and self-powered tactile sensing array (TSA) for sensitive robot skin is demonstrated based on the triboelectric effect. The device, with 4 × 4 sensing units, was composed of a top triboelectric polyethylene terephthalate (PET) layer, a bottom triboelectric copper (Cu) layer and a bottom PET substrate. A low-cost roll-to-roll ultraviolet embossing fabrication process was induced to pattern the large-scale top PET film with microstructures for high-output performance. The working mechanism and output performance of the triboelectric TSA were demonstrated and characterized, exhibiting good stability and high sensitivity. By integrating a tactile feedback system, the large-scale TSA, acting as intelligent skin for an industrial robot, was able to realize emergency avoidance and safety stop for various unknown obstacles under various working conditions. The system also has good real-time performance. By using a large-scale roll-to-roll fabrication method, this work pushes forward a significant step to self-powered triboelectric TSA and its potential applications in intelligent robot skin.
A Review and Some Complements on Quantile Risk Measures and Their Domain
Authors: Fuchs Sebastian , Schlotter Ruben , Schmidt Klaus
Published: November 2017

In the present paper, we study quantile risk measures and their domain. Our starting point is that, for a probability measure Q on the open unit interval and a wide class L Q of random variables, we define the quantile risk measure ϱ Q as the map that integrates the quantile function of a random variable in L Q with respect to Q. The definition of L Q ensures that ϱ Q cannot attain the value + ∞ and cannot be extended beyond L Q without losing this property. The notion of a quantile risk measure is a natural generalization of that of a spectral risk measure and provides another view of the distortion risk measures generated by a distribution function on the unit interval. In this general setting, we prove several results on quantile or spectral risk measures and their domain with special consideration of the expected shortfall. We also present a particularly short proof of the subadditivity of expected shortfall.
An EM Algorithm for Double-Pareto-Lognormal Generalized Linear Model Applied to Heavy-Tailed Insurance Claims
Authors: Calderín-Ojeda Enrique , Fergusson Kevin , Wu Xueyuan
Published: November 2017

Generalized linear models might not be appropriate when the probability of extreme events is higher than that implied by the normal distribution. Extending the method for estimating the parameters of a double Pareto lognormal distribution (DPLN) in Reed and Jorgensen (2004), we develop an EM algorithm for the heavy-tailed Double-Pareto-lognormal generalized linear model. The DPLN distribution is obtained as a mixture of a lognormal distribution with a double Pareto distribution. In this paper the associated generalized linear model has the location parameter equal to a linear predictor which is used to model insurance claim amounts for various data sets. The performance is compared with those of the generalized beta (of the second kind) and lognorma distributions.
Surface-Enhanced Resonance Raman Scattering of Rhodamine 6G in Dispersions and on Films of Confeito-Like Au Nanoparticles
Authors: Ujihara Masaki , Dang Nhut , Imae Toyoko
Published: November 2017

Surface-enhanced resonance Raman scattering (SERRS) of rhodamine 6G was measured on confeito-like Au nanoparticles (CAuNPs). The large CAuNPs (100 nm in diameter) in aqueous dispersion systems showed stronger enhancing effect (analytical enhancement factor: over 105) of SERRS than the small CAuNPs (50 nm in diameter), while the spherical Au nanoparticles (20 nm in diameter) displayed rather weak intensities. Especially, minor bands in 1400–1600 cm−1 were uniquely enhanced by the resonance effect of CAuNPs. The enhancement factors revealed a concentration dependence of the enhancing effect at low concentration of rhodamine 6G. This dependency was due to a large capacity of hot-spots on CAuNPs, which were formed without agglomeration. The surface-enhancing behaviour in the film systems was similar to that in the dispersions, although the large CAuNPs had lower enhancing effect in the films, and the small CAuNPs and the spherical Au nanoparticles were more effective in their films. These results suggest that the CAuNPs have an advantage in ultrasensitive devices both in dispersions and films, compared to the agglomerate of spherical Au nanoparticles.
An Embedded Wireless Sensor Network with Wireless Power Transmission Capability for the Structural Health Monitoring of Reinforced Concrete Structures
Authors: Gallucci Luca , Menna Costantino , Angrisani Leopoldo , Asprone Domenico , Moriello Rosario Schiano Lo , Bonavolontà Francesco , Fabbrocino Francesco
Published: November 2017

Maintenance strategies based on structural health monitoring can provide effective support in the optimization of scheduled repair of existing structures, thus enabling their lifetime to be extended. With specific regard to reinforced concrete (RC) structures, the state of the art seems to still be lacking an efficient and cost-effective technique capable of monitoring material properties continuously over the lifetime of a structure. Current solutions can typically only measure the required mechanical variables in an indirect, but economic, manner, or directly, but expensively. Moreover, most of the proposed solutions can only be implemented by means of manual activation, making the monitoring very inefficient and then poorly supported. This paper proposes a structural health monitoring system based on a wireless sensor network (WSN) that enables the automatic monitoring of a complete structure. The network includes wireless distributed sensors embedded in the structure itself, and follows the monitoring-based maintenance (MBM) approach, with its ABCDE paradigm, namely: accuracy, benefit, compactness, durability, and easiness of operations. The system is structured in a node level and has a network architecture that enables all the node data to converge in a central unit. Human control is completely unnecessary until the periodic evaluation of the collected data. Several tests are conducted in order to characterize the system from a metrological point of view and assess its performance and effectiveness in real RC conditions.
Adaptive Monocular Visual–Inertial SLAM for Real-Time Augmented Reality Applications in Mobile Devices
Authors: Piao Jin-Chun , Kim Shin-Dug
Published: November 2017

Simultaneous localization and mapping (SLAM) is emerging as a prominent issue in computer vision and next-generation core technology for robots, autonomous navigation and augmented reality. In augmented reality applications, fast camera pose estimation and true scale are important. In this paper, we present an adaptive monocular visual–inertial SLAM method for real-time augmented reality applications in mobile devices. First, the SLAM system is implemented based on the visual–inertial odometry method that combines data from a mobile device camera and inertial measurement unit sensor. Second, we present an optical-flow-based fast visual odometry method for real-time camera pose estimation. Finally, an adaptive monocular visual–inertial SLAM is implemented by presenting an adaptive execution module that dynamically selects visual–inertial odometry or optical-flow-based fast visual odometry. Experimental results show that the average translation root-mean-square error of keyframe trajectory is approximately 0.0617 m with the EuRoC dataset. The average tracking time is reduced by 7.8%, 12.9%, and 18.8% when different level-set adaptive policies are applied. Moreover, we conducted experiments with real mobile device sensors, and the results demonstrate the effectiveness of performance improvement using the proposed method.
Big Social Network Data and Sustainable Economic Development
Authors: Can Umit , Alatas Bilal
Published: November 2017

New information technologies have led to the rapid and effective growth of social networks. The amount of data produced by social networks has increased the value of the big data concept, which is one of the popular current phenomena. The immediate or unpredictable effects of a wide array of economic activities on large masses and the reactions to them can be measured by using social media platforms and big data methods. Thus, it would be extremely beneficial to analyze the harmful environmental and social impacts that are caused by unsustainable business applications. As social networks and big data are popular realms currently, their efficient use would be an important factor in sustainable economic development. Accurate analysis of people’s consumption habits and economic tendencies would provide significant advantages to companies. Moreover, unknown consumption factors that affect the economic preferences of individuals can be discovered and economic efficiency can be increased. This study shows that the numerous solution opportunities that are provided by social networks and big data have become significant tools in dynamic policy creation by companies and states, in solving problems related to women’s rights, the environment, and health.
Cooling Energy Implications of Occupant Factor in Buildings under Climate Change
Authors: Lim Ji , Yun Geun
Published: November 2017

Occupant factor is a critical element in the overall energy consumption of buildings. This study aims to reveal how occupant factors influence the energy consumption of example buildings in Seoul, Tokyo, and Hong Kong under climate change projections, and to prioritize factors with energy saving potential for buildings in consideration of future climate change. The study finds that the cooling degree-hours base of 23.3 °C in the three cities sharply increases with future climate change by analyzing future hourly weather data produced herein. Simulations are made with EnergyPlus Runtime Language (Erl) for modeling occupant behavior. The simulation results reveal that a dynamic thermostat control based on an adaptive comfort model is an effective method to reduce cooling energy consumption under future climate change, reducing cooling energy consumption by up to 18% in some instances. In particular, we reveal that a combined application of the adaptive comfort control, nighttime ventilation, and the use of occupancy-based lighting and equipment result in reducing cooling energy consumption by 28%. The outcomes of this study are potentially useful in providing cost-effective solutions to adapt buildings for future climate change with simple modifications to occupant behavior. Also, the roles of renewable energy are briefly discussed.
Pointers to earlier diagnosis of endometriosis: a nested case-control study using primary care electronic health records
Authors: Burton Christopher , Iversen Lisa , Bhattacharya Sohinee , Ayansina Dolapo , Saraswat Lucky , Sleeman Derek
Published: November 2017

Background

Endometriosis is a condition with relatively non-specific symptoms, and in some cases a long time elapses from first-symptom presentation to diagnosis.

Aim

To develop and test new composite pointers to a diagnosis of endometriosis in primary care electronic records.

Design and setting

This is a nested case-control study of 366 cases using the Practice Team Information database of anonymised primary care electronic health records from Scotland. Data were analysed from 366 cases of endometriosis between 1994 and 2010, and two sets of age and GP practice matched controls: (a) 1453 randomly selected females and (b) 610 females whose records contained codes indicating consultation for gynaecological symptoms.

Method

Composite pointers comprised patterns of symptoms, prescribing, or investigations, in combination or over time. Conditional logistic regression was used to examine the presence of both new and established pointers during the 3 years before diagnosis of endometriosis and to identify time of appearance.

Results

A number of composite pointers that were strongly predictive of endometriosis were observed. These included pain and menstrual symptoms occurring within the same year (odds ratio [OR] 6.5, 95% confidence interval [CI] = 3.9 to 10.6), and lower gastrointestinal symptoms occurring within 90 days of gynaecological pain (OR 6.1, 95% CI = 3.6 to 10.6). Although the association of infertility with endometriosis was only detectable in the year before diagnosis, several pain-related features were associated with endometriosis several years earlier.

Conclusion

Useful composite pointers to a diagnosis of endometriosis in GP records were identified. Some of these were present several years before the diagnosis and may be valuable targets for diagnostic support systems.
Use of an electronic consultation system in primary care: a qualitative interview study
Authors: Banks Jon , Farr Michelle , Salisbury Chris , Bernard Elly , Northstone Kate , Edwards Hannah , Horwood Jeremy
Published: November 2017

Background

The level of demand on primary care continues to increase. Electronic or e-consultations enable patients to consult their GP online and have been promoted as having potential to improve access and efficiency.

Aim

To evaluate whether an e-consultation system improves the ability of practice staff to manage workload and access.

Design and setting

A qualitative interview study in general practices in the West of England that piloted an e-consultation system for 15 months during 2015 and 2016.

Method

Practices were purposefully sampled by location and level of e-consultation use. Clinical, administrative, and management staff were recruited at each practice. Interviews were transcribed and analysed thematically.

Results

Twenty-three interviews were carried out across six general practices. Routine e-consultations offered benefits for the practice because they could be completed without direct contact between GP and patient. However, most e-consultations resulted in GPs needing to follow up with a telephone or face-to-face appointment because the e-consultation did not contain sufficient information to inform clinical decision making. This was perceived as adding to the workload and providing some patients with an alternative route into the appointment system. Although this was seen as offering some patient benefit, there appeared to be fewer benefits for the practices.

Conclusion

The experiences of the practices in this study demonstrate that the technology, in its current form, fell short of providing an effective platform for clinicians to consult with patients and did not justify their financial investment in the system. The study also highlights the challenges of remote consultations, which lack the facility for real time interactions.
Training Oncoplastic Breast Surgeons: The Canadian Fellowship Experience
Authors: Maxwell J. , Arnaout A. , Hanrahan R. , Brackstone M.
Published: November 2017

Background: Oncoplastic breast surgery combines traditional oncologic breast conservation with plastic surgery techniques to achieve improved aesthetic and quality-of-life outcomes without sacrificing oncologic safety. Clinical uptake and training remain limited in the Canadian surgical system. In the present article, we detail the current state of oncoplastic surgery (OPS) training in Canada, the United States, and worldwide, as well as the experience of a Canadian clinical fellow in OPS. Methods: The clinical fellow undertook a 9-month audit of breast surgical cases. All cases performed during the fellow’s OPS fellowship were included. The fellowship ran from October 2015 to June 2016. Results: During the 9 months of the fellowship, 67 mastectomies were completed (30 simple, 17 modified radical, 12 skin-sparing, and 8 nipple-sparing). The fellow participated in 13 breast reconstructions. Of 126 lumpectomies completed, 79 incorporated oncoplastic techniques. Conclusions: The experience of the most recent OPS clinical fellow suggests that Canadian OPS training is feasible and achievable. Commentary on the current state of Canadian OPS training suggests areas for improvement. Oncoplastic surgery is an important skill for breast surgical oncologists, and access to training should be improved for Canadian surgeons.
Short-Course Lenalidomide Plus Low-Dose Dexamethasone in the Treatment of Newly Diagnosed Multiple Myeloma—A Single-Centre Pragmatic Study
Authors: Jose W. M. , Pavithran K. , Ganesan T. S.
Published: November 2017

Purpose: We assessed response to treatment, toxicity, time to progression, progression-free survival, and overall survival in patients newly diagnosed with multiple myeloma who were ineligible for or unwilling to undergo transplantation and who were treated with a combination of lenalidomide and low-dose dexamethasone for a fixed 6 cycles in a resource-constrained environment. Methods: This pragmatic study, conducted in a single tertiary cancer centre in South India, enrolled patients from May 2009 till April 2011. Treatment included lenalidomide 25 mg daily for 21 days, with dexamethasone 40 mg on days 1, 8, 15, and 22 of a 28-day cycle, for 6 cycles. Response was evaluated after the 3rd and 6th cycles of treatment. All patients were followed for 5 years. Results: The study enrolled 51 patients. Median age in the group was 61 years (range: 38–76 years). Immunoglobulin G or A myeloma constituted 70.6% of the diagnoses, and light-chain myeloma constituted 29.4%. Stages I, II, and III (International Staging System) disease constituted 21.4%, 28.6%, and 50% of the diagnoses respectively. All patients were transplantation-eligible, but 34 (66.7%) refused for economic reasons. After treatment, 19.6% of the patients achieved a stringent complete response; 35.3%, a complete response; 5.9%, a very good partial response; and 29.4%, a partial response, for an overall response rate of 90.2%. Stable disease was seen in 3.9% of patients, and progressive disease, in 5.9%. Grade 3 or greater nonhematologic and hematologic toxicity occurred in 35.2% and 11.7% of patients respectively. Pulmonary embolism occurred in 1 patient. No patient experienced deep-vein thrombosis or peripheral neuropathy. The median follow-up duration was 66 months. All patients experienced disease progression. Median progression-free survival was 16 months. In 10 patients, re-challenge with lenalidomide and dexamethasone achieved a second complete response. At the time of writing, 19 patients had died. The overall survival rate at 5 years was 62.74%. Median overall survival is not yet reached. Conclusions: In a resource-constrained setting, lenalidomide with low-dose dexamethasone is an effective treatment with acceptable toxicity in patients newly diagnosed with multiple myeloma and not planned for transplantation. Complete responses were significantly more frequent than reported in the Western literature. Occurrence of clinical deep-vein thrombosis was rare, but hyperglycemia was common. An abbreviated course of treatment is suboptimal in multiple myeloma. Maintenance regimens should be advocated.
Conditional Survival after a Diagnosis of Malignant Brain Tumour in Canada: 2000–2008
Authors: Yuan Y. , Ross J. , Shi Q. , Davis F. G.
Published: November 2017

Background: “Conditional survival probability” is defined as the probability that a patient will survive an additional time, given that the patient has already survived a defined period of time after diagnosis. Such estimates might be more relevant for clinicians and patients during post-diagnosis care, because survival probability projections are based on the patient’s survival to date. Here, we provides the first population-based estimates of conditional survival probabilities by histology for brain cancer in Canada. Methods: Canadian Cancer Registry data were accessed for patients diagnosed with primary brain cancers during 2000–2008. Kaplan–Meier survival probabilities were estimated by histology. Conditional survival probabilities at 6 months (short-term, denoted SCS) and 2 years (long-term, denoted LCS) were derived from the Kaplan–Meier survival estimates for a range of time periods. Results: Among the 20,875 patients who met the study criteria, SCS increased by a margin of 16–18 percentage points from 6-month survivors to 2-year survivors for the three most aggressive brain cancers. The LCS for 2-year survivors was 66% or greater for all tumour groups except glioblastoma. The LCS for 4-year survivors was 62% or greater for all histologies. For glioblastoma and diffuse astrocytoma, the LCS increased each year after diagnosis. For all other histologies, the LCS first increased and then plateaued from 2 years after diagnosis. The LCS and SCS both worsened with increasing older age at diagnosis. Summary: We report histologically specific conditional survival probabilities that can have value for clinicians practicing in Canada as they plan the course of follow-up for individual patients with brain cancer.
A Case of Metastatic Prostate Cancer and Immune Thrombocytopenia
Authors: Betsch D. M. , Gray S. , Zed S. E.
Published: November 2017

Prostate cancer frequently metastasizes to bone, but bone marrow involvement is relatively less common. In advanced prostate cancer, significant bone marrow infiltration can result in hematologic abnormalities such as anemia and thrombocytopenia. We report the case of a patient who presented with a new diagnosis of thrombocytopenia at the same time that he presented with prostate cancer metastatic to bone. He was found to have immune thrombocytopenia (ITP) which responded to treatment with steroids. We discuss this case and review the literature on ITP in the setting of advanced malignancy.
The Clinical Significance of Occult Gynecologic Primary Tumours in Metastatic Cancer
Authors: Hannouf M. B. , Winquist E. , Mahmud S. M. , Brackstone M. , Sarma S. , Rodrigues G. , Rogan P. K. , Hoch J. S. , Zaric G. S.
Published: November 2017

Objective: We estimated the frequency of occult gynecologic primary tumours (GPTS) in patients with metastatic cancer from an uncertain primary and evaluated the effect on disease management and overall survival (OS). Methods: We used Manitoba administrative health databases to identify all patients initially diagnosed with metastatic cancer during 2002–2011. We defined patients as having an “occult” primary tumour if the primary was classified at least 6 months after the initial diagnosis. Otherwise, we considered patients to have “obvious” primaries. We then compared clinicopathologic and treatment characteristics and 2-year OS for women with occult and with obvious GPTS. We used Cox regression adjustment and propensity score methods to assess the effect on OS of having an occult GPT. Results: Among the 5953 patients diagnosed with metastatic cancer, occult primary tumours were more common in women (n = 285 of 2552, 11.2%) than in men (n = 244 of 3401, 7.2%). In women, GPTS were the most frequent occult primary tumours (n = 55 of 285, 19.3%). Compared with their counterparts having obvious GPTS, women with occult GPTS (n = 55) presented with similar histologic and metastatic patterns but received fewer gynecologic diagnostic examinations during diagnostic work-up. Women with occult GPTS were less likely to undergo surgery, waited longer for radiotherapy, and received a lesser variety of chemotherapeutic agents. Having an occult compared with an obvious gpt was associated with decreased OS (hazard ratio: 1.62; 95% confidence interval: 1.2 to 2.35). Similar results were observed in adjusted analyses. Conclusions: In women with metastatic cancer from an uncertain primary, GPTS constitute the largest clinical entity. Accurate diagnosis of occult GPTS early in the course of metastatic cancer might lead to more effective treatment decisions and improved survival outcomes.
Cost Analysis of Breast Cancer Diagnostic Assessment Programs
Authors: Honein-AbouHaidar G.N. , Hoch J. S. , Dobrow M. J. , Stuart-McEwan T. , McCready D. R. , Gagliardi A. R.
Published: November 2017

Objectives: Diagnostic assessment programs (DAPS) appear to improve the diagnosis of cancer, but evidence of their cost-effectiveness is lacking. Given that no earlier study used secondary financial data to estimate the cost of diagnostic tests in the province of Ontario, we explored how to use secondary financial data to retrieve the cost of key diagnostic test services in DAPS, and we tested the reliability of that cost-retrieving method with hospital-reported costs in preparation for future cost-effectiveness studies. Methods: We powered our sample at an alpha of 0.05, a power of 80%, and a margin of error of ±5%, and randomly selected a sample of eligible patients referred to a dap for suspected breast cancer during 1 January–31 December 2012. Confirmatory diagnostic tests received by each patient were identified in medical records. Canadian Classification of Health Intervention procedure codes were used to search the secondary financial data Web portal at the Ontario Case Costing Initiative for an estimate of the direct, indirect, and total costs of each test. The hospital-reported cost of each test received was obtained from the host-hospital’s finance department. Descriptive statistics were used to calculate the cost of individual or group confirmatory diagnostic tests, and the Wilcoxon signed-rank test or the paired t-test was used to compare the Ontario Case Costing Initiative and hospital-reported costs. Results: For the 191 identified patients with suspected breast cancer, the estimated total cost of $72,195.50 was not significantly different from the hospital-reported total cost of $72,035.52 (p = 0.24). Costs differed significantly when multiple tests to confirm the diagnosis were completed during one patient visit and when confirmatory tests reported in hospital data and in medical records were discrepant. The additional estimated cost for non-salaried physicians delivering diagnostic services was $28,387.50. Conclusions: It was feasible to use secondary financial data to retrieve the cost of key diagnostic tests in a breast cancer dap and to compare the reliability of the costs obtained by that estimation method with hospital-reported costs. We identified the strengths and challenges of each approach. Lessons learned from this study have to be taken into consideration in future cost-effectiveness studies.
Staging and Surgical Approaches in Gastric Cancer: A Clinical Practice Guideline
Authors: Coburn N. , Cosby R. , Klein L. , Knight G. , Malthaner R. , Mamazza J. , Mercer C. D. , Ringash J.
Published: November 2017

Background: Resection is the cornerstone of cure for gastric adenocarcinoma; however, several aspects of surgical intervention remain controversial or are suboptimally applied at a population level, including staging, extent of lymphadenectomy (LND), minimum number of lymph nodes that have to be assessed, gross resection margins, use of minimally invasive surgery, and relationship of surgical volumes with patient outcomes and resection in stage IV gastric cancer. Methods: Literature searches were conducted in databases including MEDLINE (up to 10 June 2016), EMBASE (up to week 24 of 2016), the Cochrane Library and various other practice guideline sites and guideline developer Web sites. A practice guideline was developed. Results: One guideline, seven systematic reviews, and forty-eight primary studies were included in the evidence base for this guidance document. Seven recommendations are presented. Conclusions: All patients should be discussed at a multidisciplinary team meeting, and computed tomography (CT) imaging of chest and abdomen should always be performed when staging patients. Diagnostic laparoscopy is useful in the determination of M1 disease not visible on ct images. A D2 LND is preferred for curative-intent resection of gastric cancer. At least 16 lymph nodes should be assessed for adequate staging of curative-resected gastric cancer. Gastric cancer surgery should aim to achieve an R0 resection margin. In the metastatic setting, surgery should be considered only for palliation of symptoms. Patients should be referred to higher-volume centres and those that have adequate support to manage potential complications. Laparoscopic resections should be performed to the same standards as those for open resections, by surgeons who are experienced in both advanced laparoscopic surgery and gastric cancer management.
Timeliness of the Oncology Drug Review Process for Public Funding in Canada
Authors: Younis T. , Skedgel C.
Published: November 2017

The oncology drug review process for public funding in Canada (Figure 1) encompasses both. [...]
Expanding the molecular-ruler process through vapor deposition of hexadecanethiol
Authors: Patron Alexandra M , Hooker Timothy S , Santavicca Daniel F , Causey Corey P , Mullen Thomas J
Published: November 2017

The development of methods to produce nanoscale features with tailored chemical functionalities is fundamental for applications such as nanoelectronics and sensor fabrication. The molecular-ruler process shows great utility for this purpose as it combines top-down lithography for the creation of complex architectures over large areas in conjunction with molecular self-assembly, which enables precise control over the physical and chemical properties of small local features. The molecular-ruler process, which most commonly uses mercaptoalkanoic acids and metal ions to generate metal-ligated multilayers, can be employed to produce registered nanogaps between metal features. Expansion of this methodology to include molecules with other chemical functionalities could greatly expand the overall versatility, and thus the utility, of this process. Herein, we explore the use of alkanethiol molecules as the terminating layer of metal-ligated multilayers. During this study, it was discovered that the solution deposition of alkanethiol molecules resulted in low overall surface coverage with features that varied in height. Because features with varied heights are not conducive to the production of uniform nanogaps via the molecular-ruler process, the vapor-phase deposition of alkanethiol molecules was explored. Unlike the solution-phase deposition, alkanethiol islands produced by vapor-phase deposition exhibited markedly higher surface coverages of uniform heights. To illustrate the applicability of this method, metal-ligated multilayers, both with and without an alkanethiol capping layer, were utilized to create nanogaps between Au features using the molecular-ruler process.
Evidence That the Directly Imaged Planet HD 131399 Ab Is a Background Star
Authors: Nielsen Eric L. , Rosa Robert J. De , Rameau Julien , Wang Jason J. , Esposito Thomas M. , Millar-Blanchaer Maxwell A. , Marois Christian , Vigan Arthur , Ammons S. Mark , Artigau Etienne , Bailey Vanessa P. , Blunt Sarah , Bulger Joanna , Chilcote Jeffrey , Cotten Tara , Doyon René , Duchêne Gaspard , Fabrycky Daniel , Fitzgerald Michael P. , Follette Katherine B. , Gerard Benjamin L. , Goodsell Stephen J. , Graham James R. , Greenbaum Alexandra Z. , Hibon Pascale , Hinkley Sasha , Hung Li-Wei , Ingraham Patrick , Jensen-Clem Rebecca , Kalas Paul , Konopacky Quinn , Larkin James E. , Macintosh Bruce , Maire Jérôme , Marchis Franck , Metchev Stanimir , Morzinski Katie M. , Murray-Clay Ruth A. , Oppenheimer Rebecca , Palmer David , Patience Jennifer , Perrin Marshall , Poyneer Lisa , Pueyo Laurent , Rafikov Roman R. , Rajan Abhijith , Rantakyrö Fredrik T. , Ruffio Jean-Baptiste , Savransky Dmitry , Schneider Adam C. , Sivaramakrishnan Anand , Song Inseok , Soummer Remi , Thomas Sandrine , Wallace J. Kent , Ward-Duong Kimberly , Wiktorowicz Sloane , Wolff Schuyler
Published: November 2017

We present evidence that the recently discovered, directly imaged planet HD 131399 Ab is a background star with nonzero proper motion. From new JHK1L′ photometry and spectroscopy obtained with the Gemini Planet Imager, VLT/SPHERE, and Keck/NIRC2, and a reanalysis of the discovery data obtained with VLT/SPHERE, we derive colors, spectra, and astrometry for HD 131399 Ab. The broader wavelength coverage and higher data quality allow us to reinvestigate its status. Its near-infrared spectral energy distribution excludes spectral types later than L0 and is consistent with a K or M dwarf, which are the most likely candidates for a background object in this direction at the apparent magnitude observed. If it were a physically associated object, the projected velocity of HD 131399 Ab would exceed escape velocity given the mass and distance to HD 131399 A. We show that HD 131399 Ab is also not following the expected track for a stationary background star at infinite distance. Solving for the proper motion and parallax required to explain the relative motion of HD 131399 Ab, we find a proper motion of 12.3 mas yr−1. When compared to predicted background objects drawn from a galactic model, we find this proper motion to be high but consistent with the top 4% fastest-moving background stars. From our analysis, we conclude that HD 131399 Ab is a background K or M dwarf.
Further Lunar Occultations from the 2.4 m Thai National Telescope
Authors: Richichi A. , Tasuya O. , Irawati P. , Yadav R. K.
Published: November 2017

We present the latest lunar occultation (LO) results obtained at the 2.4 m Thai National Telescope, continuing a program started in 2014. We report on 21 LO events for 20 stellar sources, yielding 7 binary stars, 1 angular diameter, and 1 star with extended circumstellar emission. These results, some of which are obtained for the first time, are discussed in the context of previous observations when available.
Polarized Transmission Spectrum of Earth as Observed during a Lunar Eclipse
Authors: Takahashi Jun , Itoh Yoichi , Hosoya Kensuke , Yanamandra-Fisher Padma A. , Hattori Takashi
Published: November 2017

Polarization during a lunar eclipse is a forgotten mystery. Coyne & Pellicori reported the detection of significant polarization during the lunar eclipse on 1968 April 13. Multiple scattering during the first transmission through Earth’s atmosphere was suggested as a possible cause of the polarization, but no conclusive determination was made. No further investigations on polarization during a lunar eclipse are known. We revisit this mystery with an interest in possible application to extrasolar planets; if planetary transmitted light is indeed polarized, it may be possible to investigate an exoplanet atmosphere using “transit polarimetry.” Here we report results of the first spectropolarimetry for the Moon during a lunar eclipse on 2015 April 4. We observed polarization degrees of 2%–3% at wavelengths of 500–600 nm; in addition, an enhanced feature was detected at the O2 A band near 760 nm. The observed time variation and wavelength dependence are consistent with an explanation of polarization caused by double scattering during the first transmission through Earth’s atmosphere, accompanied by latitudinal atmospheric inhomogeneity. Transit polarimetry for exoplanets may be useful to detect O2 gas and to probe the latitudinal atmospheric inhomogeneity, and it is thus worthy of serious consideration.
A Zone of Preferential Ion Heating Extends Tens of Solar Radii from the Sun
Authors: Kasper J. C. , Klein K. G. , Weber T. , Maksimovic M. , Zaslavsky A. , Bale S. D. , Maruca B. A. , Stevens M. L. , Case A. W.
Published: November 2017

The extreme temperatures and nonthermal nature of the solar corona and solar wind arise from an unidentified physical mechanism that preferentially heats certain ion species relative to others. Spectroscopic indicators of unequal temperatures commence within a fraction of a solar radius above the surface of the Sun, but the outer reach of this mechanism has yet to be determined. Here we present an empirical procedure for combining interplanetary solar wind measurements and a modeled energy equation including Coulomb relaxation to solve for the typical outer boundary of this zone of preferential heating. Applied to two decades of observations by the Wind spacecraft, our results are consistent with preferential heating being active in a zone extending from the transition region in the lower corona to an outer boundary 20–40 solar radii from the Sun, producing a steady-state super-mass-proportional α-to-proton temperature ratio of 5.2–5.3. Preferential ion heating continues far beyond the transition region and is important for the evolution of both the outer corona and the solar wind. The outer boundary of this zone is well below the orbits of spacecraft at 1 au and even closer missions such as Helios and MESSENGER, meaning it is likely that no existing mission has directly observed intense preferential heating, just residual signatures. We predict that the Parker Solar Probe will be the first spacecraft with a perihelion sufficiently close to the Sun to pass through the outer boundary, enter the zone of preferential heating, and directly observe the physical mechanism in action.
Molecular Gas in Debris Disks around Young A-type Stars
Authors: Moór Attila , Curé Michel , Kóspál Ágnes , Ábrahám Péter , Csengeri Timea , Eiroa Carlos , Gunawan Diah , Henning Thomas , Hughes A. Meredith , Juhász Attila , Pawellek Nicole , Wyatt Mark
Published: November 2017

According to the current paradigm of circumstellar disk evolution, gas-rich primordial disks evolve into gas-poor debris disks that are composed of second-generation dust. To explore the transition between these phases, we searched for 12CO, 13CO, and C18O emission in seven dust-rich debris disks around young A-type stars, using the Atacama Large Millimeter/submillimeter Array (ALMA) in Band 6. We discovered molecular gas in three debris disks. In all of these disks, the 12CO line was optically thick, highlighting the importance of less abundant molecules in reliable mass estimates. By supplementing our target list with literature data, we compiled a volume-limited sample of dust-rich debris disks around young A-type stars within 150 pc. We obtained a CO detection rate of 11/16 above a 12CO J = 2–1 line luminosity threshold of ∼1.4 × 104 Jy km s−1pc2 in the sample. This high incidence implies that the presence of CO gas in the bright debris disks around young A-type stars is more likely the rule than the exception. Interestingly, dust-rich debris disks around young FG-type stars exhibit, with the same detectability threshold as A-type stars, a significantly lower gas incidence. While the transition from the protoplanetary phase to the debris phase is associated with a drop in the dust content, our results exhibit a large spread in the CO mass in our debris sample, with peak values that are comparable to those in the protoplanetary Herbig Ae disks. In the particularly CO-rich debris systems, the gas may have a primordial origin, which is a characteristic of a hybrid disk.
Deuterium Fractionation upon the Formation of Hexamethylenetetramines through Photochemical Reactions of Interstellar Ice Analogs Containing Deuterated Methanol Isotopologues
Authors: Oba Yasuhiro , Takano Yoshinori , Naraoka Hiroshi , Kouchi Akira , Watanabe Naoki
Published: November 2017

Hexamethylenetetramine (HMT) is a representative product after the photolysis of interstellar ice analogs containing methanol followed by warming-up to room temperature. Since interstellar methanol is often significantly enriched in deuterium (D), the HMT photoproduct is expected to inherit D atoms from deuterated methanol. However, D fractionation upon the formation of HMT is not well understood, especially when it is produced from partly deuterated methanol isotopologues such as CH2DOH and CH3OD. Here, we experimentally studied the composition of deuterated HMT (d

n
-HMT, where n is the number of D atoms) at the isotopologue level formed by the photolysis of ice mixtures containing deuterated methanol, CH2DOH or CH3OD, at 10 or 77 K. The analyses were performed using a state-of-the-art high-resolution mass spectrometer coupled with a compound-specific separation technique. The formation of d

n
-HMT (n = 0–8) was confirmed under all experimental conditions. In addition, methyl- and hydroxyl-substituted HMT and their deuterated isotopologues were also obtained in the products. The deuterium enrichment was outstanding when CH2DOH was used rather than CH3OD, and when photolysis was performed at 77 K rather than 10 K. We found that the deuteration level of the formed HMT far exceeded that of the reactants under the present experimental conditions. These results obtained during stable isotope probing of deuterium strongly suggest that HMT can play a role as an organic pool of interstellar D atoms. These may be distributed into other chemical species through molecular evolution in space.
Long-term Spectral Variability of the Ultraluminous X-Ray Source Holmberg IX X–1
Authors: Jithesh V. , Misra Ranjeev , Wang Zhongxiang
Published: November 2017

We investigate the long-term spectral variability in the ultraluminous X-ray source Holmberg IX X–1. By analyzing the data from 8 Suzaku and 13 XMM-Newton observations conducted between 2001 and 2015, we perform a detailed spectral modeling for all spectra with simple models and complex physical models. We find that the spectra can be well explained by a disk-plus-thermal-Comptonization model. Applying this model, we unveil correlations between the X-ray luminosity (

L

X

) and the spectral parameters. One particular correlation is the statistically significant positive correlation between

L

X

and the photon index (Γ), while at the high luminosities of

>
2
×

10

40

erg

s

−
1

, the source becomes marginally hard, which results in a change in the slope of the

Γ
–

L

X

correlation. Similar variability behavior is observed in the optical depth of the source around

L

X

∼
2
×

10

40

erg

s

−
1

as the source becomes more optically thick. We consider the scenario that a corona covers the inner part of the disk, and the correlations can be explained as being driven by the variability of seed photons from the disk input into the corona. On the basis of the disk-corona model, we discuss the physical processes that are possibly indicated by the variability of the spectral parameters. Our analysis reveals the complex variability behavior of Holmberg IX X–1 and the variability mechanism is likely related to the geometry of the X-ray-emitting regions.
Detecting Binary Compact-object Mergers with Gravitational Waves: Understanding and Improving the Sensitivity of the PyCBC Search
Authors: Nitz Alexander H. , Dent Thomas , Dal Canton Tito , Fairhurst Stephen , Brown Duncan A.
Published: November 2017

We present an improved search for binary compact-object mergers using a network of ground-based gravitational-wave detectors. We model a volumetric, isotropic source population and incorporate the resulting distribution over signal amplitude, time delay, and coalescence phase into the ranking of candidate events. We describe an improved modeling of the background distribution, and demonstrate incorporating a prior model of the binary mass distribution in the ranking of candidate events. We find an

∼
10
%

and

∼
20
%

increase in detection volume for simulated binary neutron star and neutron star black hole systems, respectively, corresponding to a reduction of the false alarm rates assigned to signals by between one and two orders of magnitude.
The Intensity Modulation of the Fluorescent Line by a Finite Light Speed Effect in Accretion-powered X-Ray Pulsars
Authors: Yoshida Yuki , Kitamoto Shunji , Hoshino Akio
Published: November 2017

The X-ray line diagnostic method is a powerful tool for an investigation of plasma around accretion-powered X-ray pulsars. We point out an apparent intensity modulation of emission lines, with their rotation period of neutron stars, due to the finite speed of light (we call this effect the “finite light speed effect”) if the line emission mechanism is a kind of reprocessing, such as fluorescence or recombination after ionization by X-ray irradiation from pulsars. The modulation amplitude is determined by the size of the emission region, which is in competition with the smearing effect by the light crossing time in the emission region. This is efficient if the size of the emission region is roughly comparable to that of the rotation period multiplied by the speed of light. We apply this effect to a symbiotic X-ray pulsar, GX 1+4, where a spin modulation of the intense iron line of which has been reported. The finite light speed effect can explain the observed intensity modulation if its fluorescent region is the size of

∼

10

12

cm.
Widespread Presence of Glycolaldehyde and Ethylene Glycol around Sagittarius B2
Authors: Li Juan , Shen Zhiqiang , Wang Junzhi , Chen Xi , Li Di , Wu Yajun , Dong Jian , Zhao Rongbing , Gou Wei , Wang Jinqing , Li Shanghuo , Wang Bingru , Zheng Xingwu
Published: November 2017

We report the detection of widespread CH2OHCHO and HOCH2CH2OH emission in Galactic center giant molecular cloud Sagittarius B2 using the Shanghai Tianma 65 m Radio Telescope. Our observations show for the first time that the spatial distribution of these two important prebiotic molecules extends over 15 arcmin, corresponding to a linear size of approximately 36 pc. These two molecules are not just distributed in or near the hot cores. The abundance of these two molecules seems to decrease from the cold outer region to the central region associated with star formation activity. Results presented here suggest that these two molecules are likely to form through a low temperature process. Recent theoretical and experimental studies demonstrated that prebiotic molecules can be efficiently formed in icy grain mantles through several pathways. However, these complex ice features cannot be directly observed, and most constraints on the ice compositions come from millimeter observations of desorbed ice chemistry products. These results, combined with laboratory studies, strongly support the existence of abundant prebiotic molecules in ices.
The Impact of Progenitor Mass Loss on the Dynamical and Spectral Evolution of Supernova Remnants
Authors: Patnaude Daniel J. , Lee Shiu-Hang , Slane Patrick O. , Badenes Carles , Nagataki Shigehiro , Ellison Donald C. , Milisavljevic Dan
Published: November 2017

There is now substantial evidence that the progenitors of some core-collapse supernovae undergo enhanced or extreme mass loss prior to explosion. The imprint of this mass loss is observed in the spectra and dynamics of the expanding blast wave on timescales of days to years after core collapse, and the effects on the spectral and dynamical evolution may linger long after the supernova has evolved into the remnant stage. In this paper, we present, for the first time, largely self-consistent end-to-end simulations for the evolution of a massive star from the pre-main sequence, up to and through core collapse, and into the remnant phase. We present three models and compare and contrast how the progenitor mass-loss history impacts the dynamics and spectral evolution of the supernovae and supernova remnants. We study a model that only includes steady mass loss, a model with enhanced mass loss over a period of ∼5000 yr prior to core collapse, and a model with extreme mass loss over a period of ∼500 yr prior to core collapse. The models are not meant to address any particular supernova or supernova remnant, but rather to highlight the important role that the progenitor evolution plays in the observable qualities of supernovae and supernova remnants. Through comparisons of these three different progenitor evolution scenarios, we find that the mass loss in late stages (during and after core carbon burning) can have a profound impact on the dynamics and spectral evolution of the supernova remnant centuries after core collapse.