42 research outputs found

    The first super-Earth Detection from the High Cadence and High Radial Velocity Precision Dharma Planet Survey

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    The Dharma Planet Survey (DPS) aims to monitor about 150 nearby very bright FGKM dwarfs (within 50 pc) during 2016-2020 for low-mass planet detection and characterization using the TOU very high resolution optical spectrograph (R\approx100,000, 380-900nm). TOU was initially mounted to the 2-m Automatic Spectroscopic Telescope at Fairborn Observatory in 2013-2015 to conduct a pilot survey, then moved to the dedicated 50-inch automatic telescope on Mt. Lemmon in 2016 to launch the survey. Here we report the first planet detection from DPS, a super-Earth candidate orbiting a bright K dwarf star, HD 26965. It is the second brightest star (V=4.4V=4.4 mag) on the sky with a super-Earth candidate. The planet candidate has a mass of 8.47±0.47MEarth\pm0.47M_{\rm Earth}, period of 42.38±0.0142.38\pm0.01 d, and eccentricity of 0.040.03+0.050.04^{+0.05}_{-0.03}. This RV signal was independently detected by Diaz et al. (2018), but they could not confirm if the signal is from a planet or from stellar activity. The orbital period of the planet is close to the rotation period of the star (39-44.5 d) measured from stellar activity indicators. Our high precision photometric campaign and line bisector analysis of this star do not find any significant variations at the orbital period. Stellar RV jitters modeled from star spots and convection inhibition are also not strong enough to explain the RV signal detected. After further comparing RV data from the star's active magnetic phase and quiet magnetic phase, we conclude that the RV signal is due to planetary-reflex motion and not stellar activity.Comment: 13 pages, 17 figures, Accepted for publication in MNRA

    The first super-Earth detection from the high cadence and high radial velocity precision Dharma Planet Survey

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    The Dharma Planet Survey (DPS) aims to monitor about 150 nearby very bright FGKM dwarfs (within 50 pc) during 2016–2020 for low-mass planet detection and characterization using the TOU very high resolution optical spectrograph (⁠R≈100000⁠, 380–900 nm). TOU was initially mounted to the 2-m Automatic Spectroscopic Telescope at Fairborn Observatory in 2013–2015 to conduct a pilot survey, then moved to the dedicated 50-inch automatic telescope on Mt. Lemmon in 2016 to launch the survey. Here, we report the first planet detection from DPS, a super-Earth candidate orbiting a bright K dwarf star, HD 26965. It is the second brightest star (V = 4.4 mag) on the sky with a super-Earth candidate. The planet candidate has a mass of 8.47 ± 0.47MEarth, period of 42.38 ± 0.01 d, and eccentricity of 0.04+0.05−0.03⁠. This radial velocity (RV) signal was independently detected by Díaz et al., but they could not confirm if the signal is from a planet or stellar activity. The orbital period of the planet is close to the rotation period of the star (39–44.5 d) measured from stellar activity indicators. Our high precision photometric campaign and line bisector analysis of this star do not find any significant variations at the orbital period. Stellar RV jitters modelled from star-spots and convection inhibition are also not strong enough to explain the RV signal detected. After further comparing RV data from the star’s active magnetic phase and quiet magnetic phase, we conclude that the RV signal is due to planetary-reflex motion and not stellar activity

    Childhood adversity, mental health and suicide (CHASE): a protocol for a longitudinal case-control linked data study

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    IntroductionSuicide is a tragic outcome with devastating consequences. In 2018, Scotland experienced a 15% increase in suicide from 680 to 784 deaths. This was marked among young people, with an increase of 53% in those aged 15-24, the highest since 2007. Early intervention in those most at risk is key, but identification of individuals at risk is complex, and efforts remain largely targeted towards universal suicide prevention strategies with little evidence of effectiveness. Recent evidence suggests childhood adversity is a predictor of subsequent poor social and health outcomes, including suicide. This protocol reports on methodology for harmonising lifespan hospital contacts for childhood adversity, mental health, and suicidal behaviour. This will inform where to 1) focus interventions, 2) prioritise trauma-informed approaches, and 3) adapt support avenues earlier in life for those most at risk.MethodsThis study will follow a case-control design. Scottish hospital data (physical health SMR01; mental health SMR04; maternity/birth record SMR02; mother’s linked data SMR01, SMR04, death records) from 1981 to as recent as available will be extracted for people who died by suicide aged 10-34, and linked on Community Health Index unique identifier. A randomly selected control population matched on age and geography at death will be extracted in a 1:10 ratio. International Classification of Disease (ICD) codes will be harmonised between ICD9-CM, ICD9, ICD10-CM and ICD10 for childhood adversity, mental health, and suicidal behaviour.ResultsICD codes for childhood adversity from four key studies are reported in two categories, 1) Maltreatment or violence-related codes, and 2) Codes suggestive of maltreatment. ‘Clinical Classifications Software’ ICD codes to operationalise mental health codes are also reported. Harmonised lifespan ICD categories were achieved semi-automatically, but required labour-intensive supplementary manual coding. Cross-mapped codes are reported.ConclusionThere is a dearth of evidence about touchpoints prior to suicide. This study reports methods and harmonised ICD codes along the lifespan to understand hospital contact patterns for childhood adversity, which come to the attention of hospital practitioners

    The impact of surgical delay on resectability of colorectal cancer: An international prospective cohort study

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    AIM: The SARS-CoV-2 pandemic has provided a unique opportunity to explore the impact of surgical delays on cancer resectability. This study aimed to compare resectability for colorectal cancer patients undergoing delayed versus non-delayed surgery. METHODS: This was an international prospective cohort study of consecutive colorectal cancer patients with a decision for curative surgery (January-April 2020). Surgical delay was defined as an operation taking place more than 4 weeks after treatment decision, in a patient who did not receive neoadjuvant therapy. A subgroup analysis explored the effects of delay in elective patients only. The impact of longer delays was explored in a sensitivity analysis. The primary outcome was complete resection, defined as curative resection with an R0 margin. RESULTS: Overall, 5453 patients from 304 hospitals in 47 countries were included, of whom 6.6% (358/5453) did not receive their planned operation. Of the 4304 operated patients without neoadjuvant therapy, 40.5% (1744/4304) were delayed beyond 4 weeks. Delayed patients were more likely to be older, men, more comorbid, have higher body mass index and have rectal cancer and early stage disease. Delayed patients had higher unadjusted rates of complete resection (93.7% vs. 91.9%, P = 0.032) and lower rates of emergency surgery (4.5% vs. 22.5%, P < 0.001). After adjustment, delay was not associated with a lower rate of complete resection (OR 1.18, 95% CI 0.90-1.55, P = 0.224), which was consistent in elective patients only (OR 0.94, 95% CI 0.69-1.27, P = 0.672). Longer delays were not associated with poorer outcomes. CONCLUSION: One in 15 colorectal cancer patients did not receive their planned operation during the first wave of COVID-19. Surgical delay did not appear to compromise resectability, raising the hypothesis that any reduction in long-term survival attributable to delays is likely to be due to micro-metastatic disease

    Beyond Time and Space: using AI to Solve Client Service Challenges Now and Into the Future

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    One of the biggest challenges for libraries today is fulfilling client service requests 24/7. We have skilled staff in the Library during the day and evening, and LiveChat for those not able to visit in person, but what happens after hours? Who is there to help those who work shifts, have children, live on the other side of the planet or just prefer studying at 2am? Artificial intelligence (AI) promises an affordable solution, but will it provide the quality, flexibility and authenticity needed to ensure client satisfaction? Importantly, can the accuracy and veracity of responses be assured? At the University of Wollongong, the Library has teamed up with Academic AI specialists, Engineering and Information Science Faculty and a team of exceptionally gifted students to solve this problem. Using a combination of Agile Scrum and design thinking methodology to ensure client satisfaction and service needs were met, the team commenced building a chatbot designed to converse, provide assistance, and refer clients when needed – in other words: to create, rather than recruit, a new Library staff member. This paper will explore the journey, noting the challenges, breakthroughs and methodologies used to create and evaluate the chatbot

    Algorithms for the correction of photobleaching

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    The measured intensity (ideally in units of photon counts) of a fluorescent sample over time constitutes a time-series called an intensity trace. The idea of fluorescence fluctuation spectroscopy (FFS) is to extract information from intensity traces. Photobleaching is the phenomenon of the breaking of fluorophores (light emitters) over time. Photobleaching causes fluorescent signal to diminish over time. This changes the intensity trace, introducing a downward trend. Many quantitative methods in FFS implicitly assume that there is no bleaching in the data. Hence, data with significant levels of photobleaching must be corrected prior to the application of equations and algorithms in these fields. This correction is often termed detrending, since its aim is to remove the downward trend in the data introduced by photobleaching. Previous detrending methods have two main caveats: 1. They rely on either fitting or smoothing, both of which approximate data as continuous. This is inappropriate for fluorescence intensity data, which is count data (i.e. discrete, not continuous). 2. They require the user to choose a detrending parameter. The choice of this parameter is crucial to the success or failure of the detrending routine, yet instructions on how to choose it did not exist. The work in this thesis solves problems 1 and 2 above by means of an automatic (no user input required) parameter finding routine and a new detrending algorithm which treats the data as discrete and avoids fitting and smoothing, thereby avoiding the approximation of non-continuous data as continuous. These advancements are then used in a study investigating the stoichiometry of the interaction of the HIV-1 virus’ envelope with its cellular receptors and coreceptors over time. This is the first study of its kind in live cells and it was facilitated by the advances in detrending presented in this thesis.</p

    Algorithms for the correction of photobleaching

    No full text
    The measured intensity (ideally in units of photon counts) of a fluorescent sample over time constitutes a time-series called an intensity trace. The idea of fluorescence fluctuation spectroscopy (FFS) is to extract information from intensity traces. Photobleaching is the phenomenon of the breaking of fluorophores (light emitters) over time. Photobleaching causes fluorescent signal to diminish over time. This changes the intensity trace, introducing a downward trend. Many quantitative methods in FFS implicitly assume that there is no bleaching in the data. Hence, data with significant levels of photobleaching must be corrected prior to the application of equations and algorithms in these fields. This correction is often termed detrending, since its aim is to remove the downward trend in the data introduced by photobleaching. Previous detrending methods have two main caveats: 1. They rely on either fitting or smoothing, both of which approximate data as continuous. This is inappropriate for fluorescence intensity data, which is count data (i.e. discrete, not continuous). 2. They require the user to choose a detrending parameter. The choice of this parameter is crucial to the success or failure of the detrending routine, yet instructions on how to choose it did not exist. The work in this thesis solves problems 1 and 2 above by means of an automatic (no user input required) parameter finding routine and a new detrending algorithm which treats the data as discrete and avoids fitting and smoothing, thereby avoiding the approximation of non-continuous data as continuous. These advancements are then used in a study investigating the stoichiometry of the interaction of the HIV-1 virusâ envelope with its cellular receptors and coreceptors over time. This is the first study of its kind in live cells and it was facilitated by the advances in detrending presented in this thesis.</p

    rorynolan/ccnandb: First release

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    The version of the software used in the submission of the HIV stoichiometry paper, December 2017

    The influence of pre-operative antibiotic administration on post-operative morbidity in dental implant placement

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    TX-1-875The success of dental implants for the rehabilitation of both the partially and fully edentulous patient is well documented in the scientific literature. There are no clear guidelines on the use of prophylactic antibiotics in dental implant surgery. There are different protocols being used worldwide and these are often adopted at the surgeons? discretion. There are obvious risks associated with the over prescription of antibiotics such as adverse effects and the increasing emergence of resistant bacterial strains
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