48-year-old with Coronavirus Disease 2019

Case Presentation: A 48-year-old male who presented with signs and symptoms suggestive of an upper respiratory infection was seen at an urgent care, he had a negative chest radiograph and was discharged. With no other cases of coronavirus disease 2019 (COVID-19) in the state, the patient presented to the emergency department two days later with worsening shortness of breath.Discussion: There are a variety of findings on both chest radiograph and computed tomography of the chest that suggests COVID-19

Aperture synthesis for gravitational-wave data analysis: Deterministic Sources

Gravitational wave detectors now under construction are sensitive to the phase of the incident gravitational waves. Correspondingly, the signals from the different detectors can be combined, in the analysis, to simulate a single detector of greater amplitude and directional sensitivity: in short, aperture synthesis. Here we consider the problem of aperture synthesis in the special case of a search for a source whose waveform is known in detail: \textit{e.g.,} compact binary inspiral. We derive the likelihood function for joint output of several detectors as a function of the parameters that describe the signal and find the optimal matched filter for the detection of the known signal. Our results allow for the presence of noise that is correlated between the several detectors. While their derivation is specialized to the case of Gaussian noise we show that the results obtained are, in fact, appropriate in a well-defined, information-theoretic sense even when the noise is non-Gaussian in character. The analysis described here stands in distinction to ``coincidence analyses'', wherein the data from each of several detectors is studied in isolation to produce a list of candidate events, which are then compared to search for coincidences that might indicate common origin in a gravitational wave signal. We compare these two analyses --- optimal filtering and coincidence --- in a series of numerical examples, showing that the optimal filtering analysis always yields a greater detection efficiency for given false alarm rate, even when the detector noise is strongly non-Gaussian.Comment: 39 pages, 4 figures, submitted to Phys. Rev.

On the crosscorrelation between Gravitational Wave Detectors for detecting association with Gamma Ray Bursts

Crosscorrelation of the outputs of two Gravitational Wave (GW) detectors has recently been proposed [1] as a method for detecting statistical association between GWs and Gamma Ray Bursts (GRBs). Unfortunately, the method can be effectively used only in the case of stationary noise. In this work a different crosscorrelation algorithm is presented, which may effectively be applied also in non-stationary conditions for the cumulative analysis of a large number of GRBs. The value of the crosscorrelation at zero delay, which is the only one expected to be correlated to any astrophysical signal, is compared with the distribution of crosscorrelation of the same data for all non-zero delays within the integration time interval. This background distribution is gaussian, so the statistical significance of an experimentally observed excess would be well-defined. Computer simulations using real noise data of the cryogenic GW detectors Explorer and Nautilus with superimposed delta-like signals were performed, to test the effectiveness of the method, and theoretical estimates of its sensitivity compared to the results of the simulation. The effectiveness of the proposed algorithm is compared to that of other cumulative techniques, finding that the algorithm is particularly effective in the case of non-gaussian noise and of a large (100-1000s) and unpredictable delay between GWs and GRBs.Comment: 7 pages, 4 figures, 1 table. Submitted by Phys. Rev.

Modeling Maxwell's demon with a microcanonical Szilard engine

Following recent work by Marathe and Parrondo [PRL, 104, 245704 (2010)], we construct a classical Hamiltonian system whose energy is reduced during the adiabatic cycling of external parameters, when initial conditions are sampled microcanonically. Combining our system with a device that measures its energy, we propose a cyclic procedure during which energy is extracted from a heat bath and converted to work, in apparent violation of the second law of thermodynamics. This paradox is resolved by deriving an explicit relationship between the average work delivered during one cycle of operation, and the average information gained when measuring the system's energy

Measurement of Critical Contact Angle in a Microgravity Space Experiment

Mathematical theory predicts that small changes in container shape or in contact angle can give rise to large shifts of liquid in a microgravity environment. This phenomenon was investigated in the Interface Configuration Experiment on board the USML-2 Space Shuttle flight. The experiment's "double proboscis" containers were designed to strike a balance between conflicting requirements of sizable volume of liquid shift (for ease of observation) and abruptness of the shift (for accurate determination of critical contact angle). The experimental results support the classical concept of macroscopic contact angle and demonstrate the role of hysteresis in impeding orientation toward equilibrium

Cardiopulmonary resuscitation quality: Widespread variation in data intervals used for analysis

AIM: There is a growing body of evidence for the relationship between CPR quality and survival in cardiac arrest patients. We sought to describe the characteristics of the analysis intervals used across studies. METHODS: Relevant papers were selected as described in our recent systematic review. From these papers we collected information about (1) the time interval used for analysis; (2) the event that marked the beginning of the analysis interval; and (3) the minimum amount of CPR quality data required for a case to be included in the analysed cohort. We then compared this data across papers. RESULTS: Twenty-one studies reported on the association between CPR quality and cardiac arrest patient survival. In two thirds of studies data from the start of the resuscitation episode was analysed, in particular the first 5minutes. Commencement of the analysis interval was marked by various events including ECG pad placement and first chest compression. Nine studies specified a minimum amount of data that had to have been collected for the individual case to be included in the analysis; most commonly one minute of data. The use of shorter intervals allowed for inclusion of more cases as it included cases that did not have a complete dataset. CONCLUSION: To facilitate comparisons across studies, a standardized definition of the data analysis interval should be developed; one that maximises the amount of cases available without compromising the data's representability of the resuscitation effort

Testing Alternative Theories of Gravity using LISA

We investigate the possible bounds which could be placed on alternative theories of gravity using gravitational wave detection from inspiralling compact binaries with the proposed LISA space interferometer. Specifically, we estimate lower bounds on the coupling parameter \omega of scalar-tensor theories of the Brans-Dicke type and on the Compton wavelength of the graviton \lambda_g in hypothetical massive graviton theories. In these theories, modifications of the gravitational radiation damping formulae or of the propagation of the waves translate into a change in the phase evolution of the observed gravitational waveform. We obtain the bounds through the technique of matched filtering, employing the LISA Sensitivity Curve Generator (SCG), available online. For a neutron star inspiralling into a 10^3 M_sun black hole in the Virgo Cluster, in a two-year integration, we find a lower bound \omega > 3 * 10^5. For lower-mass black holes, the bound could be as large as 2 * 10^6. The bound is independent of LISA arm length, but is inversely proportional to the LISA position noise error. Lower bounds on the graviton Compton wavelength ranging from 10^15 km to 5 * 10^16 km can be obtained from one-year observations of massive binary black hole inspirals at cosmological distances (3 Gpc), for masses ranging from 10^4 to 10^7 M_sun. For the highest-mass systems (10^7 M_sun), the bound is proportional to (LISA arm length)^{1/2} and to (LISA acceleration noise)^{-1/2}. For the others, the bound is independent of these parameters because of the dominance of white-dwarf confusion noise in the relevant part of the frequency spectrum. These bounds improve and extend earlier work which used analytic formulae for the noise curves.Comment: 16 pages, 9 figures, submitted to Classical & Quantum Gravit

The relationship between personality traits, self-report conscientiousness the Conscientiousness Index and academic performance in undergraduate medical students

Personality traits are now accepted as being important factors within the workplace and medical education. Both cognitive ability and conscientiousness have been shown as important predictors of work-related performance within organisational research1. Conscientiousness is in an important trait within any career, but in particular within medicine where a lack of diligence can be disastrous and potentially cost lives. Within undergraduate students, objective measurement of conscientiousness is important since conscientious students are more likely to set and achieve goals. Durham University utilises the Conscientiousness Index (CI) as an objective scalar measure of conscientiousness. The CI has previously been validated against staff and peer views of student professionalism4,5. This study aimed to investigate the relationships between the Big Five personality domains (including the 6 sub-facets of conscientiousness), Conscientiousness Index scores and academic performance in medical students in order to determine whether self-report conscientiousness correlates with the Conscientiousness Index and whether a relationship with academic performance exists

The Origin of Black Hole Entropy in String Theory

I review some recent work in which the quantum states of string theory which are associated with certain black holes have been identified and counted. For large black holes, the number of states turns out to be precisely the exponential of the Bekenstein-Hawking entropy. This provides a statistical origin for black hole thermodynamics in the context of a potential quantum theory of gravity.Comment: 18 pages (To appear in the proceedings of the Pacific Conference on Gravitation and Cosmology, Seoul, Korea, February 1-6, 1996.