Establishing the content validity in Hong Kong of the prioritised criteria of consultation competence in the Leicester Assessment Package (LAP)

Objective: To test the content validity in Hong Kong of the prioritised criteria of consultation competence in the Leicester Assessment Package (LAP). Design: A detailed questionnaire was sent to doctors with experience of family medicine in Hong Kong to seek their views on the seven prioritised consultation categories and 39 component competences in the LAP on a six-point scale (strongly approve to strongly disapprove). Respondents also had the opportunity to reject or suggest alternative categories, components and/or weightings. Background demographic and professional data were collected. Subjects: 489 full members of the HKCFP with current Hong Kong postal address. Main outcome measure: The respondents' collated levels of approval of the LAP consultation categories, component competences and weightings and any consensus for changes. Results: There was a response rate of 57%. Of the respondents 92%, and 82% to 97% either strongly approved or approved of the overall LAP set of consultation categories and the individual categories respectively. Thirty-seven of the 39 suggested component competences were supported by more than 80% of respondents. There was little support for excluding, including or shifting any categories or component competences. Ninety-three percent of respondents were in favour of the need to identify priorities between any categories of consultation competence and 88% of respondents expressed approval of the suggested weightings. Conclusion: The high levels of approval from respondents suggest that the content validity of the categories and components of consultation competence in the LAP has been established in Hong Kong and that the LAP weightings of consultation categories have also been validated. Indeed, the results closely correlate with the findings of the original study in the United Kingdom. The LAP criteria of consultation competence may be used with confidence as measures against which consultation performance can be judged in formative or regulatory assessment (and improvement) of consultation competence in family medicine in Hong Kong.published_or_final_versio

Optimal leverage from non-ergodicity

In modern portfolio theory, the balancing of expected returns on investments against uncertainties in those returns is aided by the use of utility functions. The Kelly criterion offers another approach, rooted in information theory, that always implies logarithmic utility. The two approaches seem incompatible, too loosely or too tightly constraining investors' risk preferences, from their respective perspectives. The conflict can be understood on the basis that the multiplicative models used in both approaches are non-ergodic which leads to ensemble-average returns differing from time-average returns in single realizations. The classic treatments, from the very beginning of probability theory, use ensemble-averages, whereas the Kelly-result is obtained by considering time-averages. Maximizing the time-average growth rates for an investment defines an optimal leverage, whereas growth rates derived from ensemble-average returns depend linearly on leverage. The latter measure can thus incentivize investors to maximize leverage, which is detrimental to time-average growth and overall market stability. The Sharpe ratio is insensitive to leverage. Its relation to optimal leverage is discussed. A better understanding of the significance of time-irreversibility and non-ergodicity and the resulting bounds on leverage may help policy makers in reshaping financial risk controls.Comment: 17 pages, 3 figures. Updated figures and extended discussion of ergodicit

Rotating black holes with equal-magnitude angular momenta in d=5 Einstein-Gauss-Bonnet theory

We construct rotating black hole solutions in Einstein-Gauss-Bonnet theory in five spacetime dimensions. These black holes are asymptotically flat, and possess a regular horizon of spherical topology and two equal-magnitude angular momenta associated with two distinct planes of rotation. The action and global charges of the solutions are obtained by using the quasilocal formalism with boundary counterterms generalized for the case of Einstein-Gauss-Bonnet theory. We discuss the general properties of these black holes and study their dependence on the Gauss-Bonnet coupling constant $\alpha$. We argue that most of the properties of the configurations are not affected by the higher derivative terms. For fixed $\alpha$ the set of black hole solutions terminates at an extremal black hole with a regular horizon, where the Hawking temperature vanishes and the angular momenta attain their extremal values. The domain of existence of regular black hole solutions is studied. The near horizon geometry of the extremal solutions is determined by employing the entropy function formalism.Comment: 25 pages, 7 figure

Thermodynamic instability of doubly spinning black objects

We investigate the thermodynamic stability of neutral black objects with (at least) two angular momenta. We use the quasilocal formalism to compute the grand canonical potential and show that the doubly spinning black ring is thermodynamically unstable. We consider the thermodynamic instabilities of ultra-spinning black objects and point out a subtle relation between the microcanonical and grand canonical ensembles. We also find the location of the black string/membrane phases of doubly spinning black objects.Comment: 25 pages, 7 figures v2: matches the published versio

Moisture transport by Atlantic tropical cyclones onto the North American continent

Tropical Cyclones (TCs) are an important source of freshwater for the North American continent. Many studies have tried to estimate this contribution by identifying TC-induced precipitation events, but few have explicitly diagnosed the moisture fluxes across continental boundaries. We design a set of attribution schemes to isolate the column-integrated moisture fluxes that are directly associated with TCs and to quantify the flux onto the North American Continent due to TCs. Averaged over the 2004–2012 hurricane seasons and integrated over the western, southern and eastern coasts of North America, the seven schemes attribute 7 to 18 % (mean 14 %) of total net onshore flux to Atlantic TCs. A reduced contribution of 10 % (range 9 to 11 %) was found for the 1980–2003 period, though only two schemes could be applied to this earlier period. Over the whole 1980–2012 period, a further 8 % (range 6 to 9 % from two schemes) was attributed to East Pacific TCs, resulting in a total TC contribution of 19 % (range 17 to 22 %) to the ocean-to-land moisture transport onto the North American continent between May and November. Analysis of the attribution uncertainties suggests that incorporating details of individual TC size and shape adds limited value to a fixed radius approach and TC positional errors in the ERA-Interim reanalysis do not affect the results significantly, but biases in peak wind speeds and TC sizes may lead to underestimates of moisture transport. The interannual variability does not appear to be strongly related to the El Nino-Southern Oscillation phenomenon

Trends in Diagnosis and Surgical Management of Patients with Perforated Peptic Ulcer

Introduction While the laparoscopic treatment of perforated peptic ulcers (PPU) has been shown to be feasible and safe, its implementation into routine clinical practice has been slow. Only a few studies have evaluated its overall utility. The aim of this study was to investigate changes in surgical management of PPU and associated outcomes. Material and Methods The study was a retrospective, single institution, population-based review of all patients undergoing surgery for PPU between 2003 and 2009. Patient demographics, diagnostic evaluation, management, and outcomes were evaluated. Results Included were 114 patients with a median age of 67 years (range, 20–100). Women comprised 59% and were older (p<0.001), had more comorbidities (p=0.002), and had a higher Boey risk score (p=0.036) compared to men. Perforation location was gastric/pyloric in 72% and duodenal in 28% of patients. Pneumoperitoneum was diagnosed by plain abdominal x-ray in 30 of 41 patients (75%) and by abdominal computerized tomography (CT) in 76 of 77 patients (98%; p<0.001). Laparoscopic treatment was initiated in 48 patients (42%) and completed in 36 patients (75% of attempted cases). Laparoscopic treatment rate increased from 7% to 46% during the study period (p=0.02). Median operation time was shorter in patients treated via laparotomy (70 min) compared to laparoscopy (82 min) and those converted from laparoscopy to laparotomy (105 min; p=0.017). Postoperative complications occurred in 56 patients (49%). Overall 30-day postoperative mortality was 16%. No statistically significant differences were found in morbidity and mortality between open versus laparoscopic repair. Conclusion This study demonstrates an increased use of CT as the primary diagnostic tool for PPU and of laparoscopic repair in its surgical treatment. These changes in management are not associated with altered outcomes

Heterogeneities in leishmania infantum infection : using skin parasite burdens to identify highly infectious dogs

Background: The relationships between heterogeneities in host infection and infectiousness (transmission to arthropod vectors) can provide important insights for disease management. Here, we quantify heterogeneities in Leishmania infantum parasite numbers in reservoir and non-reservoir host populations, and relate this to their infectiousness during natural infection. Tissue parasite number was evaluated as a potential surrogate marker of host transmission potential. Methods: Parasite numbers were measured by qPCR in bone marrow and ear skin biopsies of 82 dogs and 34 crab-eating foxes collected during a longitudinal study in Amazon Brazil, for which previous data was available on infectiousness (by xenodiagnosis) and severity of infection. Results: Parasite numbers were highly aggregated both between samples and between individuals. In dogs, total parasite abundance and relative numbers in ear skin compared to bone marrow increased with the duration and severity of infection. Infectiousness to the sandfly vector was associated with high parasite numbers; parasite number in skin was the best predictor of being infectious. Crab-eating foxes, which typically present asymptomatic infection and are non-infectious, had parasite numbers comparable to those of non-infectious dogs. Conclusions: Skin parasite number provides an indirect marker of infectiousness, and could allow targeted control particularly of highly infectious dogs

Accurate Detection of Recombinant Breakpoints in Whole-Genome Alignments

We propose a novel method for detecting sites of molecular recombination in multiple alignments. Our approach is a compromise between previous extremes of computationally prohibitive but mathematically rigorous methods and imprecise heuristic methods. Using a combined algorithm for estimating tree structure and hidden Markov model parameters, our program detects changes in phylogenetic tree topology over a multiple sequence alignment. We evaluate our method on benchmark datasets from previous studies on two recombinant pathogens, Neisseria and HIV-1, as well as simulated data. We show that we are not only able to detect recombinant regions of vastly different sizes but also the location of breakpoints with great accuracy. We show that our method does well inferring recombination breakpoints while at the same time maintaining practicality for larger datasets. In all cases, we confirm the breakpoint predictions of previous studies, and in many cases we offer novel predictions

Cryo-EM structure of a helicase loading intermediate containing ORC-Cdc6-Cdt1-MCM2-7 bound to DNA

In eukaryotes, the Cdt1-bound replicative helicase core MCM2-7 is loaded onto DNA by the ORC-Cdc6 ATPase to form a prereplicative complex (pre-RC) with an MCM2-7 double hexamer encircling DNA. Using purified components in the presence of ATP-γS, we have captured in vitro an intermediate in pre-RC assembly that contains a complex between the ORC-Cdc6 and Cdt1-MCM2-7 heteroheptamers called the OCCM. Cryo-EM studies of this 14-subunit complex reveal that the two separate heptameric complexes are engaged extensively, with the ORC-Cdc6 N-terminal AAA+ domains latching onto the C-terminal AAA+ motor domains of the MCM2-7 hexamer. The conformation of ORC-Cdc6 undergoes a concerted change into a right-handed spiral with helical symmetry that is identical to that of the DNA double helix. The resulting ORC-Cdc6 helicase loader shows a notable structural similarity to the replication factor C clamp loader, suggesting a conserved mechanism of action