Towards the Formalization of Fractional Calculus in Higher-Order Logic

Fractional calculus is a generalization of classical theories of integration and differentiation to arbitrary order (i.e., real or complex numbers). In the last two decades, this new mathematical modeling approach has been widely used to analyze a wide class of physical systems in various fields of science and engineering. In this paper, we describe an ongoing project which aims at formalizing the basic theories of fractional calculus in the HOL Light theorem prover. Mainly, we present the motivation and application of such formalization efforts, a roadmap to achieve our goals, current status of the project and future milestones.Comment: 9 page

All-cause hospitalisation according to demographic group in people living with HIV in the current ART era: Recent findings from a cohort study in the UK

OBJECTIVE: We investigated differences in all-cause hospitalisation between key demographic groups among people with HIV in the UK in the current ART era. DESIGN/METHODS: We used data from the Royal Free HIV Cohort study between 2007 and 2018. Individuals were classified into five groups: men who have sex with men (MSM), Black African men who have sex with women (MSW), MSW of other ethnicity, Black African women and women of other ethnicity. We studied hospitalisations during the first year after HIV diagnosis (Analysis-A) separately from those more than one year after diagnosis (Analysis-B). In Analysis-A, time to first hospitalisation was assessed using Cox regression adjusted for age and diagnosis date. In Analysis-B, subsequent hospitalisation rate was assessed using Poisson regression, accounting for repeated hospitalisation within individuals, adjusted for age, calendar year, time since diagnosis. RESULTS: The hospitalisation rate was 30.7/100 person-years in the first year after diagnosis and 2.7/100 person-years subsequently; 52% and 13% hospitalisations respectively were AIDS-related. Compared to MSM, MSW and women were at much higher risk of hospitalisation during the first year [aHR (95%CI): 2.7 (1.7-4.3), 3.0 (2.0-4.4), 2.0 (1.3-2.9), 3.0 (2.0-4.5) for Black African MSW; other ethnicity MSW; Black African women; other ethnicity women respectively, Analysis-A] and remained at increased risk subsequently [corresponding aIRR (95% CI): 1.7 (1.2-2.4), 2.1 (1.5-2.8), 1.5 (1.1-1.9), 1.7 (1.2-2.3), Analysis-B]. CONCLUSIONS: In this setting with universal healthcare, substantial variation exists in hospitalisation risk across demographic groups, both in early and subsequent periods after HIV diagnosis, highlighting the need for targeted interventions

"My Story" - HIV positive adolescents tell their story through film

The global commitment to universal access for people in need of antiretroviral therapy has transformed the lives of adolescents with HIV. In contrast, there has been limited commitment at policy or service level to the need for effective therapeutic interventions which can help them to cope with their life experiences. It is imperative that the scale up of antiretroviral therapy programmes is accompanied by evidence-based therapeutic approaches if we are to assist adolescents to make informed treatment and secondary prevention decisions and to enjoy happy, fulfilled lives. This pilot study sought to evaluate the digital storytelling process as a therapeutic intervention for 12 HIV positive adolescents and young people within Africaid's Zvandiri programme in Harare, Zimbabwe. Drawing on narrative therapy, each storyteller created a digital film in which they narrated their life experiences and dominant themes in their lives. Storytellers found the process therapeutic as it helped them to move away from the negative themes which dominated their lives to a newer, richer perspective of their lives in which they had overcome challenges. Their films have provided caregivers and programmers with new insights into the challenges they faced and appropriate interventions for other adolescents living with HIV

Sperm death and dumping in Drosophila

Mating with more than one male is the norm for females of many species. In addition to generating competition between the ejaculates of different males, multiple mating may allow females to bias sperm use. In Drosophila melanogaster, the last male to inseminate a female sires approximately 80% of subsequent progeny. Both sperm displacement, where resident sperm are removed from storage by the incoming ejaculate of the copulating male, and sperm incapacitation, where incoming seminal fluids supposedly interfere with resident sperm, have been implicated in this pattern of sperm use. But the idea of incapacitation is problematic because there are no known mechanisms by which an individual could damage rival sperm and not their own. Females also influence the process of sperm use, but exactly how is unclear. Here we show that seminal fluids do not kill rival sperm and that any 'incapacitation' is probably due to sperm ageing during sperm storage. We also show that females release stored sperm from the reproductive tract (sperm dumping) after copulation with a second male and that this requires neither incoming sperm nor seminal fluids. Instead, males may cause stored sperm to be dumped or females may differentially eject sperm from the previous mating

Persistent drying in the tropics linked to natural forcing.

Approximately half of the world's population lives in the tropics, and future changes in the hydrological cycle will impact not just the freshwater supplies but also energy production in areas dependent upon hydroelectric power. It is vital that we understand the mechanisms/processes that affect tropical precipitation and the eventual surface hydrological response to better assess projected future regional precipitation trends and variability. Paleo-climate proxies are well suited for this purpose as they provide long time series that pre-date and complement the present, often short instrumental observations. Here we present paleo-precipitation data from a speleothem located in Mesoamerica that reveal large multi-decadal declines in regional precipitation, whose onset coincides with clusters of large volcanic eruptions during the nineteenth and twentieth centuries. This reconstruction provides new independent evidence of long-lasting volcanic effects on climate and elucidates key aspects of the causal chain of physical processes determining the tropical climate response to global radiative forcing.A.W. thanks the Swiss Federal Institute of Technology both for hosting his sabbatical and for the analysis of the stable isotopes. A.W. also thanks Cluster of Excellence CliSAP at the University of Hamburg for sponsoring collaboration. Collection of GU-Xi-1 by T.M. was supported through a sabbatical granted by the University of Puerto Rico (Mayagu¨ez) and the National Geographic Society Grant no. 3089-85 to T.M. partially supported survey of the cave and location of the stalagmite. The research was supported in part by the National Science Foundation ATM-1003502. Y.K. was also supported by grant NA10OAR4310137 from the National Oceanic and Atmospheric Administration— Climate Program Office. S.F.M.B. acknowledges financial support from the Schweizer National Fond Project CRS122 132646/1. D.B. was supported by National Science Foundation Grant ATM-1003219. G.L. acknowledges support from Helmholtz through PACES and REKLIM. We acknowledge the World Climate Research Program Working Group on Coupled Modeling, which is responsible for CMIP, and we thank the climate modelling groups for producing and making available their model output. Paul Sammarco (LUMCON) is thanked for some advice regarding statistical and data interpretation. This paper is a Lamont Doherty Contribution number 7901. LB was supported by the French National Research Agency under EL PASO grant 10-Blan-608-01.This is the accepted manuscript. The final version is available at http://www.nature.com/ncomms/2015/150714/ncomms8627/full/ncomms8627.html

The Prevalence of Campylobacter amongst a Free-Range Broiler Breeder Flock Was Primarily Affected by Flock Age

Campylobacter successfully colonizes broiler chickens, but little is known about the longer term natural history of colonization, since most flocks are slaughtered at an immature age. In this study, the prevalence and genetic diversity of Campylobacter colonizing a single free-range broiler breeder flock was investigated over the course of a year. The age of the flock was the most important factor in determining both the prevalence and diversity of Campylobacter over time. There was no correlation with season, temperature, the amount of rain and sunshine, or the dynamics of colonization amongst geographically and temporally matched broiler flocks. The higher prevalence rates coincided with the age at which broiler chickens are typically slaughtered, but then in the absence of bio-security or other intervention methods, and despite changes in flock management, the prevalence fell to significantly lower levels for the remainder of the study. The genetic diversity of Campylobacter increased as the flock aged, implying that genotypes were accumulated within the flock and may persist for a long time. A better understanding of the ecology of Campylobacter within commercial chicken flocks will allow the design of more effective farm-based interventions

Diffusion of e-health innovations in 'post-conflict' settings: a qualitative study on the personal experiences of health workers.

BACKGROUND: Technological innovations have the potential to strengthen human resources for health and improve access and quality of care in challenging 'post-conflict' contexts. However, analyses on the adoption of technology for health (that is, 'e-health') and whether and how e-health can strengthen a health workforce in these settings have been limited so far. This study explores the personal experiences of health workers using e-health innovations in selected post-conflict situations. METHODS: This study had a cross-sectional qualitative design. Telephone interviews were conducted with 12 health workers, from a variety of cadres and stages in their careers, from four post-conflict settings (Liberia, West Bank and Gaza, Sierra Leone and Somaliland) in 2012. Everett Roger's diffusion of innovation-decision model (that is, knowledge, persuasion, decision, implementation, contemplation) guided the thematic analysis. RESULTS: All health workers interviewed held positive perceptions of e-health, related to their beliefs that e-health can help them to access information and communicate with other health workers. However, understanding of the scope of e-health was generally limited, and often based on innovations that health workers have been introduced through by their international partners. Health workers reported a range of engagement with e-health innovations, mostly for communication (for example, email) and educational purposes (for example, online learning platforms). Poor, unreliable and unaffordable Internet was a commonly mentioned barrier to e-health use. Scaling-up existing e-health partnerships and innovations were suggested starting points to increase e-health innovation dissemination. CONCLUSIONS: Results from this study showed ICT based e-health innovations can relieve information and communication needs of health workers in post-conflict settings. However, more efforts and investments, preferably driven by healthcare workers within the post-conflict context, are needed to make e-health more widespread and sustainable. Increased awareness is necessary among health professionals, even among current e-health users, and physical and financial access barriers need to be addressed. Future e-health initiatives are likely to increase their impact if based on perceived health information needs of intended users

Reduced susceptibility to pyrethroid insecticide treated nets by the malaria vector Anopheles gambiae s.l. in western Uganda

<p>Abstract</p> <p>Background</p> <p>Pyrethroid insecticide-treated mosquito nets are massively being scaled-up for malaria prevention particularly in children under five years of age and pregnant mothers in sub-Saharan Africa. However, there is serious concern of the likely evolution of widespread pyrethroid resistance in the malaria vector <it>Anopheles gambiae s.l</it>. due to the extensive use of pyrethroid insecticide-treated mosquito nets. The purpose of this study was to ascertain the status of pyrethroid resistance in <it>An. gambiae s.l</it>. in western Uganda.</p> <p>Methods</p> <p>Wild mosquitoes (1–2 days old) were exposed in 10 replicates to new nets impregnated with K-othrine (Deltamethrin 25 mg/m²), Solfac EW50 (Cyfluthrin 50 mg/m²) and Fendona 6SC (Cypermethrin 50 mg/m²) and observed under normal room temperature and humidity (Temperature 24.8°C���27.4°C, Humidity 65.9–45.7). A similar set of mosquitoes collected from the control area 80 km away were exposed to a deltamethrin 25 mg/m²impregnated net at the same time and under the same conditions. The 10-year mean KDT₅₀and mortality rates for each of the three pyrethroid insecticides were compared using the Student <it>t</it>-test.</p> <p>Results</p> <p>A significant increase in the mean knockdown time (KDT₅₀) and mean mortality rate were observed in almost all cases an indication of reduced susceptibility. The overall results showed a four-fold increase in the mean knockdown time (KDT₅₀) and 1.5-fold decrease in mortality rate across the three pyrethroid insecticides. There was a significant difference in the 10-year mean KDT₅₀between deltamethrin and cyfluthrin; deltamethrin and cypermethrin, but no significant difference between cyfluthrin and cypermethrin. The 10-year mean difference in KDT50 for mosquitoes exposed to deltamethrin from the control site was significantly different from that of mosquitoes from the intervention site (p<0.05, t=3.979, 9df). The 10-year mean difference in mortality rate between deltamethrin (84.64%); cyfluthrin (74.18%); cypermethrin (72.19%) and the control (90.45%) showed a significant decline in mortality across all the three insecticides.</p> <p>Conclusion</p> <p>Generally the results showed a trend of increase in mosquito resistance status with cross-resistance against all the three pyrethroid insecticides. This study reveals for the first time the development of pyrethroid resistance in <it>An. gambiae s.l</it>. in Western Uganda. It is therefore strongly recommended that the impact of this development on malaria control efforts be closely monitored and alternative fabric treatments be considered before this problem curtails community wide implementation of this malaria control strategy in Uganda.</p