On the Unique Solution of Planet and Star Parameters from an Extrasolar Planet Transit Light Curve

There is a unique solution of the planet and star parameters from a planet transit light curve with two or more transits if the planet has a circular orbit and the light curve is observed in a band pass where limb darkening is negligible. The existence of this unique solution is very useful for current planet transit surveys for several reasons. First, there is an analytic solution that allows a quick parameter estimate, in particular of Rp. Second, the stellar density can be uniquely derived from the transit light curve alone. The stellar density can be used to immediately rule out a giant star (and hence a much larger than planetary companion) and can also be used to put an upper limit on the stellar and planet radius even considering slightly evolved stars. Third, the presence of an additional fully blended star that contaminates an eclipsing system to mimic a planet transit can be largely ruled out from the transit light curve given a spectral type for the central star. Fourth, the period can be estimated from a single-transit light curve and a measured spectral type. All of these applications can be used to select the best planet transit candidates for mass determination by radial velocity follow-up. To use these applications in practice, the photometric precision and time sampling of the light curve must be high (better than 0.005 mag precision and 5 minute time sampling).Comment: 26 pages incl. 11 figs, submitted to Ap

Touchdown--A Victory for Injured Fans at Sporting Events

When fans attend sporting events, they usually do so at their own peril. Fans are expected to assume the known risks of flying baseballs, hockey pucks, or footballs. In fact, Judge Cardozo once summarized this situation by saying, “the timorous may stay at home.” While sports fans generally assume the risk of liability from acts by players that send balls flying into the stands, the question arises as to the liability of stadium owners for injuries caused when one fan injures another fan after a player has sent a ball into the crowd. In Hayden v. University of Notre Dame, the Indiana Court of Appeals found that one fan criminally injured another fan during a scramble for a loose football that had flown into the crowd after a field goal attempt. The court examined recent Indiana case law that articulated the test for determining whether a landowner’s duty is to its invitees extends to protecting them against the criminal acts of third parties. This Note evaluates the options the court faced, the potential misapplication of the law to the facts, and the dangerous policy implication that the court may have created in the process

Monitoring osteoarthritis: a cross-sectional survey in general practice

<b>Background</b> Despite being a highly prevalent chronic condition managed predominantly in primary care and unlike other chronic conditions, osteoarthritis (OA) care is delivered on an ad hoc basis rather than through routine structured review. Evidence suggests current levels of OA care are suboptimal, but little is known about what general practitioners' (GPs) consider important in OA care, and, thus, the scope to improve inconsistency or poor practice is, at present, limited.<p></p> <b>Objectives</b> We investigated GPs' views on and practice of monitoring OA. <p></p> <b>Methods</b> This was a cross-sectional postal survey of 2500 practicing UK GPs randomly selected from the Binley's database. Respondents were asked if monitoring OA patients was important and how monitoring should be undertaken.<p></p> <b>Results</b> Responses were received from 768 GPs of whom 70.8% were male and 89.5% were principals within their practices. Despite 55.4% (n = 405) indicating monitoring patients with OA was important and 78.3% (n = 596) considering GPs the appropriate professionals to monitor OA, only 15.2% (n = 114) did so routinely, and 45% (n = 337) did not monitor any OA patients at all. In total, 61.4% (n = 463) reported that patients should self-monitor. Respondents favored monitoring physical function, pain, and analgesia use over monitoring measures of BMI, self management plans, and exercise advice.<p></p> <b>Conclusions</b> The majority of respondents felt that monitoring OA was important, but this was not reflected in their reported current practice. Much of what they favored for monitoring was in line with published guidance, suggesting provision of suboptimal care does not result from lack of knowledge and interventions to improve OA care must address barriers to GPs engaging in optimal care provision

The EXPLORE Project I: A Deep Search for Transiting Extrasolar Planets

(Abridged) We discuss the design considerations of the EXPLORE (EXtra-solar PLanet Occultation REsearch) project, a series of transiting planet searches using 4-m-class telescopes to continuously monitor a single field of stars in the Galactic Plane in each ~2 week observing campaign. We discuss the general factors which determine the efficiency and the number of planets found by a transit search, including time sampling strategy and field selection. The primary goal is to select the most promising planet candidates for radial velocity follow-up observations. We show that with very high photometric precision light curves that have frequent time sampling and at least two detected transits, it is possible to uniquely solve for the main parameters of the eclipsing system (including planet radius) based on several important assumptions about the central star. Together with a measured spectral type for the star, this unique solution for orbital parameters provides a powerful method for ruling out most contaminants to transiting planet candidates. For the EXPLORE project, radial velocity follow-up observations for companion mass determination of the best candidates are done on 8-m-class telescopes within two or three months of the photometric campaigns. This same-season follow-up is made possible by the use of efficient pipelines to produce high quality light curves within weeks of the observations. We conclude by presenting early results from our first search, EXPLORE I, in which we reached <1% rms photometric precision (measured over a full night) on ~37,000 stars to I <= 18.2.Comment: accepted by ApJ. Main points unchanged but more thorough discussion of some issues. 36 pages, including 14 figure

On the Period Distribution of Close-In Extrasolar Giant Planets

Transit (TR) surveys for extrasolar planets have recently uncovered a population of ``very hot Jupiters,'' planets with orbital periods of P< 3 d. At first sight this may seem surprising, given that radial velocity (RV) surveys have found a dearth of such planets, despite the fact that their sensitivity increases with decreasing P. We examine the confrontation between RV and TR survey results, paying particular attention to selection biases that favor short-period planets in transit surveys. We demonstrate that, when such biases and small-number statistics are properly taken into account, the period distribution of planets found by RV and TR surveys are consistent at better than the 1-sigma level. This consistency holds for a large range of reasonable assumptions. In other words, there are not enough planets detected to robustly conclude that the RV and TR short-period planet results are inconsistent. Assuming a logarithmic distribution of periods, we find that the relative frequency of very hot Jupiters (VHJ: P=1-3 d) to hot Jupiters (HJ: P=3-9 d) is 10-20%. Given an absolute frequency of HJ of ~1%, this implies that approximately one star in ~500-1000 has a VHJ. We also note that VHJ and HJ appear to be distinct in terms of their upper mass limit. We discuss the implications of our results for planetary migration theories, as well as present and future TR and RV surveys.Comment: 11 pages, 4 figures, 2 tables. Minor changes. Accepted to ApJ, to appear in the April 20, 2005 issue (v623

Multifractal nature of ocular aberration dynamics of the human eye

Ocular monochromatic aberrations display dynamic behavior even when the eye is fixating on a stationary stimulus. The fluctuations are commonly characterized in the frequency domain using the power spectrum obtained via the Fourier transform. In this paper we used a wavelet-based multifractal analytical approach to provide a more in depth analysis of the nature of the aberration fluctuations. The aberrations of five subjects were measured at 21 Hz using an open-view Shack-Hartmann sensor. We show that the aberration dynamics are multifractal. The most frequently occurring Hölder exponent for the rms wavefront error, averaged across the five subjects, was 0.31 ± 0.10. This suggests that the time course of the aberration fluctuations is antipersistant. Future applications of multifractal analysis are discussed

Koopman-theoretic Approach for Identification of Exogenous Anomalies in Nonstationary Time-series Data

In many scenarios, it is necessary to monitor a complex system via a time-series of observations and determine when anomalous exogenous events have occurred so that relevant actions can be taken. Determining whether current observations are abnormal is challenging. It requires learning an extrapolative probabilistic model of the dynamics from historical data, and using a limited number of current observations to make a classification. We leverage recent advances in long-term probabilistic forecasting, namely {\em Deep Probabilistic Koopman}, to build a general method for classifying anomalies in multi-dimensional time-series data. We also show how to utilize models with domain knowledge of the dynamics to reduce type I and type II error. We demonstrate our proposed method on the important real-world task of global atmospheric pollution monitoring, integrating it with NASA's Global Earth System Model. The system successfully detects localized anomalies in air quality due to events such as COVID-19 lockdowns and wildfires.Comment: 10 pages, 8 figure

Prevalence of Occupational Stress among Secondary School Teachers in Public Schools in the District of Colombo, Sri Lanka

Teacher occupational stress is increasing globally. We aimed to determine the prevalence of occupational stress among secondary teachers, to advocate policies for prevention of occupational stress among teachers in Sri Lanka. A cross-sectional study included 1426 secondary teachers, selected using multistage cluster sampling from public schools of Colombo, Sri Lanka. Validated Teacher Stress Inventory-Sinhala (TSI-Sinhala) assessed occupational stress. Prevalence of high [15.9% (95% CI: 14.0%-17.8%)] and moderate [67.5% (95% CI: 65.1%-69.9%)] occupational stress among secondary teachers, resulted an overall high prevalence of 83.4% (95%CI: 81.4%-85.3%). Moderate occupational stress among female teachers (68.6%, 95% CI: 65.7-71.5%) was significantly higher than males (61.9%. 95% CI: 58.9-64.9%). Urgent attention to preventative interventions for occupational stress among teachers in Sri Lanka is recommended

Simulation and Interpretation of the Genesis of Tropical Storm Gert (2005) as Part of the NASA Tropical Cloud Systems and Processes Experiment

Several hypotheses have been put forward for the how tropical cyclones (tropical storms and hurricanes in the Atlantic) first develop circulation at the surface, a key event that needs to occur before a storm can begin to draw energy from the warm ocean. One hypothesis suggests that the surface circulation forms from a "top-down" approach in which a storm s rotating circulation begins at middle levels of the atmosphere and builds down to the surface through processes related to light "stratiform" (horizontally extensive) precipitation. Another hypothesis suggests a bottom-up approach in which deep thunderstorm towers (convection) play the major role in spinning up the flow at the surface. These "hot towers" form in the area of the mid-level circulation and strongly concentrate this rotation at low levels within their updrafts. Merger of several of these hot towers then intensifies the surface circulation to the point in which a storm forms. This paper examines computer simulations of Tropical Storm Gert (2005), which formed in the Gulf of Mexico during the National Aeronautics and Space Administration s (NASA) Tropical Cloud Systems and Processes (TCSP) Experiment, to investigate the development of low-level circulation and, in particular, whether stratiform or hot tower processes were responsible for the storm s formation. Data from NASA satellites and from aircraft were used to show that the model did a good job of reproducing the formation and evolution of Gert. The simulation shows that a mix of both stratiform and convective rainfall occurred within Gert. While the stratiform rainfall clearly acted to increase rotation at middle levels, the diverging outflow beneath the stratiform rain worked against spinning up the low-level winds. The hot towers appeared to dominate the low-level flow, producing intense rotation within their cores and often being associated with significant pressure falls at the surface. Over time, many of these hot towers merged, with each merger adding to the rotation of the storm and the pressure falls at the surface. This process continued to increase the strength of the storm until the storm made landfall on the east coast of Mexico. These results support the bottom-up hypothesis for development

Discussing prognosis with patients with osteoarthritis: a cross-sectional survey in general practice

Osteoarthritis is a leading cause of chronic pain and disability and one of the most common conditions diagnosed and managed in primary care. Despite the evidence that patients would value discussions about the course of osteoarthritis to help them make informed treatment decisions and plan for the future, little is known of GPs’ practice of, or views regarding, discussing prognosis with these patients. A cross-sectional postal survey asked 2500 randomly selected UK GPs their views on discussing prognosis with patients with osteoarthritis and potential barriers or facilitators to such discussions. They were also asked if prognostic discussions were part of their current practice and what indicators they considered important in assessing the prognosis associated with osteoarthritis. Of 768 respondents (response rate 30.7 %), the majority felt it necessary to discuss prognosis with osteoarthritis patients (n = 738, 96.1 %), but only two thirds reported that it was part of their routine practice (n = 498, 64.8 %). Most respondents found predicting the course of osteoarthritis (n = 703, 91.8 %) and determining the prognosis of patients difficult (n = 589, 76.7 %). Obesity, level of physical disability and pain severity were considered the most important prognostic indicators in osteoarthritis. Although GPs consider prognostic discussions necessary for patients with osteoarthritis, few prioritise these discussions. Lack of time and perceived difficulties in predicting the disease course and determining prognosis for patients with osteoarthritis may be barriers to engaging in prognostic discussions. Further research is required to identify ways to assist GPs making prognostic predictions for patients with osteoarthritis and facilitate engagement in these discussions