OPTIMIZATION OF DISCUS FLIGHT

We use a 3-D model for men’s and women’s discus flight including initial discus flight path angle β0, angle of attack α0, pitch attitude δ0 as well as release speed v0 and initial spin rate p0. We study in detail optimal release conditions depending on a constant wind velocity of v0 =5 m/s blowing from different directions γ=0°, 10° up to 350°. Here γ =0°, 180°, 90°, and 270° correspond to tail wind, head wind, wind from the left, and wind from the right, respectively. The optimal wind for men is head wind from the right (γ= 220°). In this case optimal men’s strategy at v0=25 m/s is β0 = 33°, α0= 23°, δ0= 30° with a range r=74.80 m. Optimal wind for women is wind exactly from the right (γ= 270°). The optimal women’s strategy at v0=24 m/s is β0 = 41°, α0= 32°, δ0 = 30° with a range r=61.26 m. In all cases we assume an initial spin rate of p0=50 rad/s. At the moment of release, the angle of attack α0 of the discus symmetry plane should always be less than the flight path angle β0. Also, we can show that a faster-spinning discus imparts greater gyroscopic stability and therefore achieves a better throw. We used evolutionary algorithms to perform the optimization

Reflections on a decade of delivering PMTCT in Khayelitsha, South Africa

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Using Grizzly Bears to Assess Harvest-Ecosystem Tradeoffs in Salmon Fisheries

Using grizzly bears as surrogates for “salmon ecosystem” function, the authors develop a generalizable ecosystem-based management framework that enables decision-makers to quantify ecosystem-harvest tradeoffs between wild and human recipients of natural resources like fish

How accurately do routinely reported HIV viral load suppression proportions reflect progress towards the 909090 target in the population on antiretroviral treatment in Khayelitsha South Africa

Background. The Joint United Nations Programme on HIV/AIDS (UNAIDS) third 90-90-90 target requires 90% of patients on antiretroviral treatment (ART) to be virally suppressed (<1 000 copies/mL). In Khayelitsha, Cape Town, South Africa viral load (VL) suppression of <400 copies/mL was reported as 89% in 2016, but only 56% of patients had a result recorded in routine data. We conceived a VL ‘cascade’ to represent the steps required for an expected VL to be reported as complete in routine data and thus contribute to reported VL suppression: among those for whom a VL is ‘expected’, a sample must be collected and tested (‘done’), a result must be ‘filed’ in the patient folder, ‘noted’ by a clinician and electronically ‘captured’. The low reported completion suggested gaps along the VL cascade and cast doubt on the validity of reported suppression.Objectives. To assess the validity of routinely reported VL suppression and identify barriers to VL completion.Methods. A retrospective cohort study between 1 July 2015 and 30 June 2016, which included all Khayelitsha patients receiving ART, with a routine VL expected, was conducted. We obtained data routinely captured on site and VL data from the laboratory system. A sample of 1 035 patient folders was reviewed. VL suppression was calculated using laboratory data, including all tests done, and compared with reported suppression based on on-site captured electronic data. Successful progression through each step on the VL cascade was estimated. We used logistic regression to identify factors associated with laboratory data and reported VL testing.Results. Of 22 991 patients for whom a routine VL test was due, 84% were done, 79% filed, 76% noted and 55% captured. Using all laboratory data, VL suppression was  estimated as 82%, 87%, 89% and 91% at the 50, 200, 400 and 1 000 copies/mL thresholds, respectively, but reported suppression using captured results was 80%, 86%, 88% and 89% at those thresholds. Routine VL testing is more likely to be done in children <15 years old (adjusted odds ratio (aOR) 1.89, 95% confidence interval (CI) 1.45 - 2.48) and pregnant women (aOR 1.90, 95% CI 1.28 - 2.81) than in men, adjusted for facility.Conclusions. Despite a low reported completion, VL testing completion was high. Reported suppression using captured data was similar to suppression calculated using all laboratory data, which provided an accurate measure of progress towards the 90-90-90 target. More work is needed to reach the 16% of patients missed by routine testing

Interlaboratory Evaluation of Rodent Pulmonary Responses to Engineered Nanomaterials: The NIEHS Nano GO Consortium

Background: Engineered nanomaterials (ENMs) have potential benefits, but they also present safety concerns for human health. Interlaboratory studies in rodents using standardized protocols are needed to assess ENM toxicity. Methods: Four laboratories evaluated lung responses in C57BL/6 mice to ENMs delivered by oropharyngeal aspiration (OPA), and three labs evaluated Sprague-Dawley (SD) or Fisher 344 (F344) rats following intratracheal instillation (IT). ENMs tested included three forms of titanium dioxide (TiO2) [anatase/rutile spheres (TiO2-P25), anatase spheres (TiO2-A), and anatase nanobelts (TiO2-NBs)] and three forms of multiwalled carbon nanotubes (MWCNTs) [original (O), purified (P), and carboxylic acid “functionalized� (F)]. One day after treatment, bronchoalveolar lavage fluid was collected to determine differential cell counts, lactate dehydrogenase (LDH), and protein. Lungs were fixed for histopathology. Responses were also examined at 7 days (TiO2 forms) and 21 days (MWCNTs) after treatment. Results: TiO2-A, TiO2-P25, and TiO2-NB caused significant neutrophilia in mice at 1 day in three of four labs. TiO2-NB caused neutrophilia in rats at 1 day in two of three labs, and TiO2-P25 and TiO2-A had no significant effect in any of the labs. Inflammation induced by TiO2 in mice and rats resolved by day 7. All MWCNT types caused neutrophilia at 1 day in three of four mouse labs and in all rat labs. Three of four labs observed similar histopathology to O-MWCNTs and TiO2-NBs in mice. Conclusions: ENMs produced similar patterns of neutrophilia and pathology in rats and mice. Although interlaboratory variability was found in the degree of neutrophilia caused by the three types of TiO2 nanoparticles, similar findings of relative potency for the three types of MWCNTs were found across all laboratories, thus providing greater confidence in these interlaboratory comparisons

Development of fluorescent probes for bioimaging applications

Fluorescent probes, which allow visualization of cations such as Ca2+, Zn2+ etc., small biomolecules such as nitric oxide (NO) or enzyme activities in living cells by means of fluorescence microscopy, have become indispensable tools for clarifying functions in biological systems. This review deals with the general principles for the design of bioimaging fluorescent probes by modulating the fluorescence properties of fluorophores, employing mechanisms such as acceptor-excited Photoinduced electron Transfer (a-PeT), donor-excited Photoinduced electron Transfer (d-PeT), and spirocyclization, which have been established by our group. The a-PeT and d-PeT mechanisms are widely applicable for the design of bioimaging probes based on many fluorophores and the spirocyclization process is also expected to be useful as a fluorescence off/on switching mechanism. Fluorescence modulation mechanisms are essential for the rational design of novel fluorescence probes for target molecules. Based on these mechanisms, we have developed more than fifty bioimaging probes, of which fourteen are commercially available. The review also describes some applications of the probes developed by our group to in vitro and in vivo systems

Expansion of cardiac ischemia/reperfusion injury after instillation of three forms of multi-walled carbon nanotubes

Background The exceptional physical-chemical properties of carbon nanotubes have lead to their use in diverse commercial and biomedical applications. However, their utilization has raised concerns about human exposure that may predispose individuals to adverse health risks. The present study investigated the susceptibility to cardiac ischemic injury following a single exposure to various forms of multi-walled carbon nanotubes (MWCNTs). It was hypothesized that oropharyngeal aspiration of MWCNTs exacerbates myocardial ischemia and reperfusion injury (I/R injury). Methods Oropharyngeal aspiration was performed on male C57BL/6J mice with a single amount of MWCNT (0.01 - 100 μg) suspended in 100 μL of a surfactant saline (SS) solution. Three forms of MWCNTs were used in this study: unmodified, commercial grade (C-grade), and functionalized forms that were modified either by acid treatment (carboxylated, COOH) or nitrogenation (N-doped) and a SS vehicle. The pulmonary inflammation, serum cytokine profile and cardiac ischemic/reperfusion (I/R) injury were assessed at 1, 7 and 28 days post-aspiration. Results Pulmonary response to MWCNT oropharyngeal aspiration assessed by bronchoalveolar lavage fluid (BALF) revealed modest increases in protein and inflammatory cell recruitment. Lung histology showed modest tissue inflammation as compared to the SS group. Serum levels of eotaxin were significantly elevated in the carboxylated MWCNT aspirated mice 1 day post exposure. Oropharyngeal aspiration of all three forms of MWCNTs resulted in a time and/or dose-dependent exacerbation of myocardial infarction. The severity of myocardial injury varied with the form of MWCNTs used. The N-doped MWCNT produced the greatest expansion of the infarct at any time point and required a log concentration lower to establish a no effect level. The expansion of the I/R injury remained significantly elevated at 28 days following aspiration of the COOH and N-doped forms, but not the C-grade as compared to SS. Conclusion Our results suggest that oropharyngeal aspiration of MWCNT promotes increased susceptibility of cardiac tissue to ischemia/reperfusion injury without a significant pulmonary inflammatory response. The cardiac injury effects were observed at low concentrations of MWCNTs and presence of MWCNTs may pose a significant risk to the cardiovascular system

Trends in Loss to Follow-Up among Migrant Workers on Antiretroviral Therapy in a Community Cohort in Lesotho

BACKGROUND: The provision of antiretroviral therapy (ART) to migrant populations raises particular challenges with respect to ensuring adequate treatment support, adherence, and retention in care. We assessed rates of loss to follow-up for migrant workers compared with non-migrant workers in a routine treatment programme in Morjia, Lesotho. DESIGN: All adult patients (≥18 years) initiating ART between January 1, 2008, and December 31, 2008, and followed up until the end of 2009, were included in the study. We described rates of loss to follow-up according to migrant status by Kaplan-Meier estimates, and used Poisson regression to model associations between migrant status and loss to follow-up controlling for potential confounders identified a priori. RESULTS: Our cohort comprised 1185 people, among whom 12% (148) were migrant workers. Among the migrant workers, median age was 36.1 (29.6-45.9) and the majority (55%) were male. We found no statistically significant differences between baseline characteristics and migrant status. Rates of lost to follow up were similar between migrants and non-migrants in the first 3 months but differences increased thereafter. Between 3 and 6 months after initiating antiretroviral therapy, migrants had a 2.78-fold increased rate of defaulting (95%CI 1.15-6.73); between 6 and 12 months the rate was 2.36 times greater (95%CI 1.18-4.73), whereas after 1 year the rate was 6.69 times greater (95%CI 3.18-14.09). CONCLUSIONS: Our study highlights the need for programme implementers to take into account the specific challenges that may influence continuity of antiretroviral treatment and care for migrant populations