Coherent and incoherent scatter radar study of the climatology and day-to-day variability of mean F region vertical drifts and equatorial spread F

We conducted a comprehensive analysis of the vertical drifts and equatorial spread F (ESF) measurements made by the Jicamarca incoherent scatter radar (ISR) between 1994 and 2013. The ISR measurements allowed us to construct not only updated climatological curves of quiet-time vertical plasma drifts but also time-versus-height maps of ESF occurrence over the past two solar cycles. These curves and maps allowed us to better relate the observed ESF occurrence patterns to features in the vertical drift curves than previously possible. We identified an excessively high occurrence of post-midnight F region irregularities during December solstice and low solar flux conditions. More importantly, we also found a high occurrence of ESF events during sudden stratospheric warming (SSW) events. We also proposed and evaluated metrics of evening enhancement of the vertical drifts and ESF occurrence, which allowed us to quantify the relationship between evening drifts and ESF development. Based on a day-to-day analysis of these metrics, we offer estimates of the minimum pre-reversal enhancement (PRE) peak (and mean PRE) values observed prior to ESF development for different solar flux and seasonal conditions. We also found that ESF irregularities can reach the altitudes at least as high as 800 km at the magnetic equator even during low solar flux conditions. ©2015. American Geophysical Union. All Rights Reserved

Lack of Awareness of Human Immunodeficiency Virus (HIV) Infection: Problems and Solutions With Self-reported HIV Serostatus of Men Who Have Sex With Men

Background. Lack of human immunodeficiency virus (HIV) infection awareness may be a driver of racial disparities in HIV infection amongmen who have sex withmen (MSM). Lack of awareness is typicallymeasured by comparing HIV test result to self-reported HIV status. This measure may be subject to reporting bias and alternatives are needed. Methods. The InvolveMENt study examined HIV disparities between black and whiteMSM from Atlanta. Among HIV-positive participants who did not report knowing they were positive, we examined other measures of awareness: HIV viral load (VL)/mL (low VL), antiretroviral (ARV) drugs in blood, and previous HIV case surveillance report. Results. Using self-report only, 32% (62 of 192) of black and 16% (7 of 45) of white MSM were not aware of their HIV infection (P = .03). Using self-report and low VL, 25% (48 of 192) black and 16% (7 of 45) white MSM lacked awareness (P = .18). Using self-report and ARVs, 26% (50 of 192) black and 16% (7 of 45) white MSM lacked awareness (P = .14). Using self-report and surveillance report, 15% (28 of 192) black and 13% (6 of 45) white MSM lacked awareness (P = .83). Conclusions. Self-report only may overestimate true lack of awareness of HIV status for black MSM. If, as our data suggest, black MSM are not less likely to be aware of their HIV infection than are white MSM, then this factor is not a substantial driver of HIV disparity. Future HIV research that depends on accuratemeasurement of HIV status awareness should consider including additional laboratory and case surveillance data

In vitro efficacy of Metarhizium anisopliae sensu lato against unfed Amblyomma parvum (Acari: Ixodidae).

Amblyomma parvum Aragão (Acari: Ixodidae) is a tick species found with wide distribution in the Neotropical region. Even though it is a wildlife-related tick, it is also a frequent parasite of domestic animals, is aggressive to human beings and may harbor pathogenic microorganisms. Therefore, it is a target species for control on domestic animals, particularly those at the rural?wildlife interface. Herein, the efficacy of two isolates (E9 and IBCB 425) of an entomopathogenic fungus, Metarhizium anisopliae sensu lato, already evaluated for ticks that parasitize domestic animals, was tested against unfed A. parvum adults. Both isolates displayed high acaricidal efficacy after immersion in fungal conidial suspensions for 5 min. Isolate E9 killed all ticks by the 7th day post-treatment, and isolate IBCB 425 did so by the 11th day. Tick mortality of 80 and 90% was achieved as early as the 3rd and 4th days, respectively, with both treatments. Thus, if a commercial M. anisopliae s.l. acaricide against domestic animal ticks is developed, it would also be effective against A. parvum

Differential effects of Atomoxetine on executive functioning and lexical decision in Attention-Deficit/Hyperactivity Disorder and Reading Disorder

Objective: The effects of a promising pharmacological treatment for attention-deficit/hyperactivity disorder (ADHD), atomoxetine, were studied on executive functions in both ADHD and reading disorder (RD) because earlier research demonstrated an overlap in executive functioning deficits in both disorders. In addition, the effects of atomoxetine were explored on lexical decision. Methods: Sixteen children with ADHD, 20 children with ADHD + RD, 21 children with RD, and 26 normal controls were enrolled in a randomized placebo-controlled crossover study. Children were measured on visuospatial working memory, inhibition, and lexical decision on the day of randomization and following two 28-day medication periods. Results: Children with ADHD + RD showed improved visuospatial working memory performance and, to a lesser extent, improved inhibition following atomoxetine treatment compared to placebo. No differential effects of atomoxetine were found for lexical decision in comparison to placebo. In addition, no effects of atomoxetine were demonstrated in the ADHD and RD groups. Conclusion: Atomoxetine improved visuospatial working memory and to a lesser degree inhibition in children with ADHD + RD, which suggests differential developmental pathways for co-morbid ADHD + RD as compared to ADHD and RD alone

Nitroheterocyclic drugs cure experimental <i>Trypanosoma cruzi</i> infections more effectively in the chronic stage than in the acute stage

The insect-transmitted protozoan parasite Trypanosoma cruzi is the causative agent of Chagas disease, and infects 5-8 million people in Latin America. Chagas disease is characterised by an acute phase, which is partially resolved by the immune system, but then develops as a chronic life-long infection. There is a consensus that the front-line drugs benznidazole and nifurtimox are more effective against the acute stage in both clinical and experimental settings. However, confirmative studies have been restricted by difficulties in demonstrating sterile parasitological cure. Here, we describe a systematic study of nitroheterocyclic drug efficacy using highly sensitive bioluminescence imaging of murine infections. Unexpectedly, we find both drugs are more effective at curing chronic infections, judged by treatment duration and therapeutic dose. This was not associated with factors that differentially influence plasma drug concentrations in the two disease stages. We also observed that fexinidazole and fexinidazole sulfone are more effective than benznidazole and nifurtimox as curative treatments, particularly for acute stage infections, most likely as a result of the higher and more prolonged exposure of the sulfone derivative. If these findings are translatable to human patients, they will have important implications for treatment strategies

In Vitro and In Vivo High-Throughput Assays for the Testing of Anti-Trypanosoma cruzi Compounds

The treatment of Trypanosoma cruzi infection (the cause of human Chagas disease) remains a significant challenge. Only two drugs, both with substantial toxicity, are available and the efficacy of these dugs is often questioned – in many cases due to the limitations of the methods for assessing efficacy rather than to true lack of efficacy. For these reasons relatively few individuals infected with T. cruzi actually have their infections treated. In this study, we report on innovative methods that will facilitate the discovery of new compounds for the treatment of T. cruzi infection and Chagas disease. Utilizing fluorescent and bioluminescent parasite lines, we have developed in vitro tests that are reproducible and facile and can be scaled for high-throughput screening of large compound libraries. We also validate an in vivo screening test that monitors parasite replication at the site of infection and determines the effectiveness of drug treatment in less than two weeks. More importantly, results in this rapid in vivo test show strong correlations with those obtained in long-term (e.g. 40 day or more) treatment assays. The results of this study remove one of the obstacles for identification of effective and safe compounds to treat Chagas disease