386 research outputs found
Neptune's Migration into a Stirred-Up Kuiper Belt: A Detailed Comparison of Simulations to Observations
Nbody simulations are used to examine the consequences of Neptune's outward
migration into the Kuiper Belt, with the simulated endstates being compared
rigorously and quantitatively to the observations. These simulations confirm
the findings of Chiang et al. (2003), who showed that Neptune's migration into
a previously stirred-up Kuiper Belt can account for the Kuiper Belt Objects
(KBOs) known to librate at Neptune's 5:2 resonance. We also find that capture
is possible at many other weak, high-order mean motion resonances, such as the
11:6, 13:7, 13:6, 9:4, 7:3, 12:5, 8:3, 3:1, 7:2, and the 4:1. The more distant
of these resonances, such as the 9:4, 7:3, 5:2, and the 3:1, can also capture
particles in stable, eccentric orbits beyond 50 AU, in the region of phase
space conventionally known as the Scattered Disk. Indeed, 90% of the simulated
particles that persist over the age of the Solar System in the so-called
Scattered Disk zone never had a close encounter with Neptune, but instead were
promoted into these eccentric orbits by Neptune's resonances during the
migration epoch. This indicates that the observed Scattered Disk might not be
so scattered. This model also produced only a handful of Centaurs, all of which
originated at Neptune's mean motion resonances in the Kuiper Belt. We also
report estimates of the abundances and masses of the Belt's various
subpopulations (e.g., the resonant KBOs, the Main Belt, and the so-called
Scattered Disk), and also provide upper limits on the abundance of Centaurs and
Neptune's Trojans, as well as upper limits on the sizes and abundances of
hypothetical KBOs that might inhabit the a>50 AU zone.Comment: 60 pages, 16 figures. Accepted for publication in the Astronomical
Journa
The Program for climate Model diagnosis and Intercomparison: 20-th anniversary Symposium
Twenty years ago, W. Lawrence (Larry) Gates approached the U.S. Department of Energy (DOE) Office of Energy Research (now the Office of Science) with a plan to coordinate the comparison and documentation of climate model differences. This effort would help improve our understanding of climate change through a systematic approach to model intercomparison. Early attempts at comparing results showed a surprisingly large range in control climate from such parameters as cloud cover, precipitation, and even atmospheric temperature. The DOE agreed to fund the effort at the Lawrence Livermore National Laboratory (LLNL), in part because of the existing computing environment and because of a preexisting atmospheric science group that contained a wide variety of expertise. The project was named the Program for Climate Model Diagnosis and Intercomparison (PCMDI), and it has changed the international landscape of climate modeling over the past 20 years. In spring 2009 the DOE hosted a 1-day symposium to celebrate the twentieth anniversary of PCMDI and to honor its founder, Larry Gates. Through their personal experiences, the morning presenters painted an image of climate science in the 1970s and 1980s, that generated early support from the international community for model intercomparison, thereby bringing PCMDI into existence. Four talks covered GatesÃÂâÃÂÃÂÃÂÃÂs early contributions to climate research at the University of California, Los Angeles (UCLA), the RAND Corporation, and Oregon State University through the founding of PCMDI to coordinate the Atmospheric Model Intercomparison Project (AMIP). The speakers were, in order of presentation, Warren Washington [National Center for Atmospheric Research (NCAR)], Kelly Redmond (Western Regional Climate Center), George Boer (Canadian Centre for Climate Modelling and Analysis), and Lennart Bengtsson [University of Reading, former director of the European Centre for Medium-Range Weather Forecasts (ECMWF)]. The afternoon session emphasized the scientific ideas that are the basis of PCMDIÃÂâÃÂÃÂÃÂÃÂs success, summarizing their evolution and impact. Four speakers followed the various PCMDI-supported climate model intercomparison projects, beginning with early work on cloud representations in models, presented by Robert D. Cess (Distinguished Professor Emeritus, Stony Brook University), and then the latest Cloud Feedback Model Intercomparison Projects (CFMIPs) led by Sandrine Bony (Laboratoire de MÃÂÃÂÃÂétÃÂÃÂÃÂéorologie Dynamique). Benjamin Santer (LLNL) presented a review of the climate change detection and attribution (D & A) work pioneered at PCMDI, and Gerald A. Meehl (NCAR) ended the day with a look toward the future of climate change research
Communicative moves in forestry research introductions: implications for the design of learning materials
This paper reports on a genre-based analysis of the rhetorical moves in research article introductions (RAIs) in Forestry, an established applied science discipline. Based on Swales’ (2004) revised CARS model, this study covers 20 RAs collected from four high impact Forestry journals. Our findings indicate that although Forestry RAIs largely conform to the revised CARS framework, prominent variations in step occurrences are noteworthy in comparison to those in other disciplines. The incidence of centrality claims in Forestry is significantly higher than those in some established disciplines. Research niches in Forestry are predominantly established using gap indications and positive justifications, thus showing (i) considerable similarity compared to those in Wildlife Behaviour, and (ii) notable difference compared to those in Civil Engineering. Hypothesis formulation also appears in half of the Forestry RAIs, thus exhibiting a significant distinction in comparison to those in Wildlife Behaviour and Civil Engineering. In terms of method-related summaries, Forestry resembles Civil Engineering rather than Wildlife Behaviour, given that two-thirds of Civil Engineering RAIs included such summative methodological statements while none of the writers in Wildlife Behaviour considered it necessary to incorporate this step in the beginning of a research paper. Based on the findings reported in this paper, we argue that rhetorical strategies actually constitute a crucial aspect in which different scientific disciplines can be distinguished and recognised. More importantly, varying degrees of emphasis need to be placed on different rhetorical steps while language instructors design teaching materials aimed at guiding learners in the writing of research introductions in courses on English for Research Purposes (ERP)
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Advancing Pharmacist Collaborative Care within Academic Health Systems.
INTRODUCTION:The scope of pharmacy practice has evolved over the last few decades to focus on the optimization of medication therapy. Despite this positive impact, the lack of reimbursement remains a significant barrier to the implementation of innovative pharmacist practice models. SUMMARY:We describe the successful development, implementation and outcomes of three types of pharmacist collaborative care models: (1) a pharmacist with physician oversight, (2) pharmacist-interprofessional teams and (3) physician-pharmacist teams. The outcome measurement of these pharmacist care models varied from the design phase to patient volume measurement and to comprehensive quality dashboards. All of these practice models have been successfully funded by affiliated health systems or grants. CONCLUSIONS:The expansion of pharmacist services delivered by clinical faculty has several benefits to affiliated health systems: (1) significant improvements in patient care quality, (2) access to experts in specialty areas, and (3) the dissemination of outcomes with national and international recognition, increasing the visibility of the health system
Feasibility of store-and-forward teledermatology in out-patient care: A prospective study from rural India utilising specialist referral services through an instant messaging platform - "WhatsApp"
Objectives: The COVID-19 pandemic has placed unprecedented demands on the delivery of health care in rural areas of India. We examined the feasibility of store-and-forward mobile teledermatology for outpatient access to specialist dermatologic care in underserved areas in India. Methods: We conducted a prospective study using smartphone-based teledermatology, connecting six underserved clinics manned by primary care physicians (PCP) to three dermatologists, using the instant messaging platform WhatsApp. We assessed the concordance between PCPs and dermatologists (using Cohen’s kappa coefficient), consultation time, the spectrum of conditions, and the outcome. Results: Of the 730 dermatology patients screened in the clinics, (13%) (36 males and 59 females) required teleconsultation, among which 61.1% were non-infective, 34.7% were infective, and the diagnosis could not be ascertained in 4.2 %. The mean time takenwas 13.5 (± 18.4) minutes. Twenty per cent (n=19) required referral, and 80% (n=76) of consultations could be resolved at the clinic, of whom 36.8 % were cured, 38.2% had moderate, 4% had minimal improvement, 13% were lost to follow-up, and 8% refused treatment. Cure was observed in viral infections and eczema. The diagnostic concordance ranged from low values [0.38 (95% CI: 0-0.68)] in infective to moderate [0.66 (95% CI: 0.42-0.83), p=0.033] in non-infective disorders. Conclusion: Asynchronous mobile teledermatology, using specialist referral via instant messaging platforms, is a powerful modality for providing real-time dermatologic care, while offering a very promising alternative for decreasing healthcare disparities and continuity of services even in adverse situations like the Covid-19 pandemic
An update on Gardneralla vaginalis associated bacterial vaginosis in Malaysia
Objective: To update the status of Gardnerella vaginalis (G. vaginalis) as a causative agent of bacterial vaginosis (BV) in Malaysia and to define its epidemiology, metronidazole resistance and virulence properties. Methods: It is a single-centre (Gynaecology clinic at the Hospital Kuala Lumpur, Malaysia) prospective study with laboratory-based microbiological follow up and analyses. Vaginal swabs collected from the patients suspected for BV were subjected to clinical BV diagnosis, isolation and identification of G. vaginalis, metronidazole susceptibility testing, vaginolysin and sialidase gene PCR, Piot's biotyping and amplified ribosomal DNA restriction analysis genotyping. Results: Among the 207 patients suspected for BV, G. vaginalis was isolated from 47 subjects. G. vaginalis coexisted with Trichomonas vaginalis and Candida albicans in 26 samples. Three G. vaginalis isolates were resistant to metronidazole. Biotyping revealed 1 and 7 as the common types. Amplified ribosomal DNA restriction analysis genotype II was found to be more common (n = 22; 46%) than I (n = 12; 25.53%) and III (n = 13; 27.6%). All genotype I and III isolates carried the sialidase gene, while 91.6% and 84.6% contained the vaginolysin gene. Genotype I was significantly associated with post-gynaecological surgical complications and abortions (P = 0.002). Conclusions: The existence of pathogenic G. vaginalis clones in Malaysia including drug resistant strains should not be taken lightly and needs to be monitored as these may bring more complications especially among women of child bearing age and pregnant women
Extreme debris disk variability : exploring the diverse outcomes of large asteroid impacts during the era of terrestrial planet formation
The most dramatic phases of terrestrial planet formation are thought to be oligarchic and chaotic growth, on timescales of up to 100─200 Myr, when violent impacts occur between large planetesimals of sizes up to protoplanets. Such events are marked by the production of large amounts of debris, as has been observed in some exceptionally bright and young debris disks (termed extreme debris disks). Here we report five years of Spitzer measurements of such systems around two young solar-type stars: ID8 and P1121. The short-term (weekly to monthly) and long-term (yearly) disk variability is consistent with the aftermaths of large impacts involving large asteroid-sized bodies. We demonstrate that an impact-produced clump of optically thick dust, under the influence of the dynamical and viewing geometry effects, can produce short-term modulation in the disk light curves. The long-term disk flux variation is related to the collisional evolution within the impact-produced fragments once released into a circumstellar orbit. The time-variable behavior observed in the P1121 system is consistent with a hypervelocity impact prior to 2012 that produced vapor condensates as the dominant impact product. Two distinct short-term modulations in the ID8 system suggest two violent impacts at different times and locations. Its long-term variation is consistent with the collisional evolution of two different populations of impact-produced debris dominated by either vapor condensates or escaping boulders. The bright, variable emission from the dust produced in large impacts from extreme debris disks provides a unique opportunity to study violent events during the era of terrestrial planet formation
Iris Liveness Detection Competition (LivDet-Iris) -- The 2020 Edition
Launched in 2013, LivDet-Iris is an international competition series open to
academia and industry with the aim to assess and report advances in iris
Presentation Attack Detection (PAD). This paper presents results from the
fourth competition of the series: LivDet-Iris 2020. This year's competition
introduced several novel elements: (a) incorporated new types of attacks
(samples displayed on a screen, cadaver eyes and prosthetic eyes), (b)
initiated LivDet-Iris as an on-going effort, with a testing protocol available
now to everyone via the Biometrics Evaluation and Testing
(BEAT)(https://www.idiap.ch/software/beat/) open-source platform to facilitate
reproducibility and benchmarking of new algorithms continuously, and (c)
performance comparison of the submitted entries with three baseline methods
(offered by the University of Notre Dame and Michigan State University), and
three open-source iris PAD methods available in the public domain. The best
performing entry to the competition reported a weighted average APCER of
59.10\% and a BPCER of 0.46\% over all five attack types. This paper serves as
the latest evaluation of iris PAD on a large spectrum of presentation attack
instruments.Comment: 9 pages, 3 figures, 3 tables, Accepted for presentation at
International Joint Conference on Biometrics (IJCB 2020
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