Looptop Hard X-Ray Emission in Solar Flares: Images and Statistics

The discovery of hard X-ray sources near the top of a flaring loop by the HXT instrument on board the YOHKOH satellite represents a significant progress towards the understanding of the basic processes driving solar flares. In this paper we extend the previous study of limb flares by Masuda (1994) by including all YOHKOH observations up through August 1998. We report that from October 1991 to August 1998, YOHKOH observed 20 X-ray bright limb flares (where we use the same selection criteria as Masuda), of which we have sufficient data to analyze 18 events, including 8 previously unanalyzed flares. Of these 18 events, 15 show detectable impulsive looptop emission. Considering that the finite dynamic range (about a decade) of the detection introduces a strong bias against observing comparatively weak looptop sources, we conclude that looptop emission is a common feature of all flares. We summarize the observations of the footpoint to looptop flux ratio and the spectral indices. We present light curves and images of all the important newly analyzed limb flares. Whenever possible we present results for individual pulses in multipeak flares and for different loops for multiloop flares. We then discuss the statistics of the fluxes and spectral indices of the looptop and footpoint sources taking into account observational selection biases. The importance of these observations (and those expected from the scheduled HESSI satellite with its superior angular spectral and temporal resolution) in constraining acceleration models and parameters is discussed briefly.Comment: 27 pages (13 embedded figures). Accepted for publication in Ap

A multi-data source surveillance system to detect a bioterrorism attack during the G8 summit in Scotland

In 18 weeks, Health Protection Scotland (HPS) deployed a syndromic surveillance system to early-detect natural or intentional disease outbreaks during the G8 Summit 2005 at Gleneagles, Scotland. The system integrated clinical and non-clinical datasets. Clinical datasets included Accident and Emergency (A and E) syndromes, and General Practice (GPs) codes grouped into syndromes. Non-clinical data included telephone calls to a nurse helpline, laboratory test orders, and hotel staff absenteeism. A cumulative sum-based detection algorithm and a log-linear regression model identified signals in the data. The system had a fax-based track for real-time identification of unusual presentations. Ninety-five signals were triggered by the detection algorithms and four forms were faxed to HPS. Thirteen signals were investigated. The system successfully complemented a traditional surveillance system in identifying a small cluster of gastroenteritis among the police force and triggered interventions to prevent further cases

The Effect of Defoliation Interval on Regrowth of Tall Fescue

Herbage yield, persistence and quality optimise when defoliation interval is based on physiological indicators, such as leaf regrowth stage. Examples include ryegrass (Fulkerson & Donaghy, 2001), cocksfoot (Rawnsley et al., 2002), prairie grass (Fulkerson et al., 2000) and kikuyu (Reeves et al., 1996). Yield, persistence and quality optimise because leaf regrowth stage relates closely to plant energy reserves, which generally peak as the number of live leaves/tiller maximise. More frequent defoliation than the optimum reduces energy reserves and leads to a smaller root system, fewer tillers and retarded growth rate (Fulkerson & Donaghy, 2001). Based on plant physiological development, the optimum defoliation interval for tall fescue has not been defined

Implications of using an extended lactation to change from a spring-calving to an autumn-calving farm system in South Taranaki

Recent changes to pasture-supply curves in South Taranaki, and the availability of winter milk premiums have increased farmer interest in changing from a spring-calving to an autumn-calving farm system. One approach to changing the season of calving from spring to autumn is to extend the calving interval (CI) by delaying the mating period by ~8 months, so that they next calve in autumn and undertake an extended lactation [>305 days in milk (DIM)]. A large-scale farmlet experiment was established in South Taranaki to investigate the production and reproduction responses of cows using this approach. In June 2017, 602 springcalving cows were allocated to two farmlets. In one farmlet (SPR) 301 cows were mated in October to maintain a 12-month CI spring-calving pattern. In the other farmlet (AUT, n=301 cows), mating was delayed for eight months, and cows underwent an extended lactation (mean DIM, 488; max DIM, 577) to calve next in autumn 2019. The experiment analysed two lactations for the AUT farmlet and two and a half lactations for the SPR farmlet. Across the total experimental period, milksolids (MS) production was similar between farmlets (1,194 vs. 1,174 kg MS/cow), however, cows in the AUT farmlet were fed more supplementary feed [2,371 vs. 1,951 kg dry matter (DM)/cow]. The extended lactation changed the relationship between feed supply and herd demand, which led to excessive BCS gain and ryegrass staggers for AUT farmlet cows. Further research is required to examine grazing management during extended lactations and to assess the economic implications of this approach.fals

A qualitative study of primary care professionals’ views of case finding for depression in patients with diabetes or coronary heart disease in the UK

<p>Background Routinely conducting case finding (also commonly referred to as screening) in patients with chronic illness for depression in primary care appears to have little impact. We explored the views and experiences of primary care nurses, doctors and managers to understand how the implementation of case finding/screening might impact on its effectiveness.</p> <p>Methods Two complementary qualitative focus group studies of primary care professionals including nurses, doctors and managers, in five primary care practices and five Community Health Partnerships, were conducted in Scotland.</p> <p>Results We identified several features of the way case finding/screening was implemented that may lead to systematic under-detection of depression. These included obstacles to incorporating case finding/screening into a clinical review consultation; a perception of replacing individualised care with mechanistic assessment, and a disconnection for nurses between management of physical and mental health. Far from being a standardised process that encouraged detection of depression, participants described case finding/screening as being conducted in a way which biased it towards negative responses, and for nurses, it was an uncomfortable task for which they lacked the necessary skills to provide immediate support to patients at the time of diagnosis.</p> <p>Conclusion The introduction of case finding/screening for depression into routine chronic illness management is not straightforward. Routinized case finding/screening for depression can be implemented in ways that may be counterproductive to engagement (particularly by nurses), with the mental health needs of patients living with long term conditions. If case finding/screening or engagement with mental health problems is to be promoted, primary care nurses require more training to increase their confidence in raising and dealing with mental health issues and GPs and nurses need to work collectively to develop the relational work required to promote cognitive participation in case finding/screening.</p&gt

Management of serology negative human hepatic hydatidosis (caused by Echinococcus granulosus) in a young woman from Bangladesh in a resource-rich setting: A case report

Human cystic echinococcosis (hydatidosis) is a parasitic zoonosis with almost complete worldwide distribution. Echinococcus granulosus, the dog tapeworm, causes hydatidosis which accounts for 95% of human echinococcosis. Although this tapeworm is found in dogs as a definitive host and a number of intermediate hosts, humans are often infected from close contact with infected dogs. Humans are not part of the parasitic lifecycle and serve as accidental hosts. Hydatidosis is an important consideration in the differential diagnosis of hepatic cysts in individuals from endemic areas. Clinicians should be aware of the long incubation period, the high frequency of negative serological tests, and the possibility of intraoperative evaluations of the cyst aspirate being non-diagnostic. We describe a case of serology negative hydatidosis that came to medical attention as an incidental finding in a young woman from Bangladesh. The patient underwent imaging and was then started on albendazole. After several weeks of albendazole, the cyst was punctured, aspirated, injected with hypertonic saline, re-aspirated, and then fully excised. Diagnosis was confirmed by microscopic evaluation of the cyst aspirate. Serological tests for hydatidosis may be negative in patients with early disease and thus should not be used to rule out this disease. Consideration of this diagnosis allows clinicians to avoid the catastrophic spillage of cystic contents risking an anaphylactic reaction, which might prove fatal. Despite World Health Organization hydatidosis staging being based on ultrasound, radiologists in resource-rich setting may prefer MRI in the management and staging of cystic echinococcosis

On the Spatial Distribution of Hard X-Rays from Solar Flare Loops

The aim of this paper is to investigate the spatial structure of the impulsive phase hard X-ray emission from solar flares. This work is motivated by the YOHKOH and the forthcoming HESSI observations. Summarizing past results, it is shown that the transport effects can account for the observations by inhomogeneous loops where there is a strong field convergence and/or density enhancement at the top of the flaring loop. Scattering by plasma turbulence at the acceleration site or pancake type pitch angle distribution of the accelerated electrons can also give rise to enhanced emission at the loop tops. These could be a natural consequence of acceleration by plasma waves. This paper considers a general case of stochastic scattering and acceleration that leads to an isotropic pitch angle distribution and an enhanced emission from the loop tops or the acceleration site. Following the formalism developed in earlier papers the strength and the spectrum of the radiation expected from the acceleration site and the foot points are evaluated and their dependence on the parameters describing the acceleration process and the flare plasma are determined. The theoretical ratio of these two intensities and relative values of their spectral indices are compared with the YOHKOH observations, demonstrating that the above mentioned parameters can be constrained with such observations. It is shown that future high spatial and spectral resolution observations, for example those expected from HESSI, can begin to distinguish between different models and constrain their parameters.Comment: 37 pages with 20 figures. Accepted for publication in ApJ http://www.astronomy.stanford.ed