Distribution, Abundance, and Spatial Variability of Microplastic Pollution in Surface Waters of Lake Superior

Plastic pollution in oceans and lakes has been a concern for more than three decades, and largely through the breakdown of large plastics, microplastic pollution has been of real concern for over 20 years. Most research has focused on marine settings but freshwater systems are equally vulnerable to microplastic pollution. The Laurentian Great Lakes system has been the subject of little microplastic research and Lake Superior has received even less focus than the other four lakes. The objective of this study is to fill that knowledge gap and determine the abundance and spatial distribution, spatial variability, and polymer identities of microplastic pollution in the surface waters of Lake Superior. In 2014, 94 double net samples were collected from the surface waters of Lake Superior and preserved. These samples comprise the most comprehensive surface water survey of any of the Great Lakes to date, and the first to employ double neuston net trawls. Since there is not yet a standardized sampling method, a comparison of side-by-side samples will indicate whether single net surveys are sufficient and could be used as the standard sampling method. A total of 187 samples was processed using wet peroxide oxidation and analyzed using a dissecting microscope. A sampling of all plastic particles collected were also analyzed using FTIR spectrometry to determine polymer identity. Abundances calculated throughout Lake Superior show wide variability, ranging between 4,000 to more than 100,000 particles/km2 but the majority of locations have an abundance between 20,000 to 50,000 particles/km2. Average abundance in Lake Superior is 30,271 particles/km2 (95% confidence interval of the mean ranges from 20,917 to 39,797 particles/km2) which suggests a total count of more than 2.4 billion (1.7 to 3.3 billion) particles across the lake’s surface. Both the calculated average and lake wide total for Superior are higher than Lake Michigan, which as an average abundance of 17, 276 particles/km2 and holds roughly 1 billion particles. Lake Erie is more polluted than both Lake Superior and Lake Michigan, with an average abundance of 105,502 particles/km2 and a total of roughly 2.7 billion particles. Lake Superior was expected to have lower abundances than Lake Michigan because of lower population density and industrialization, but the higher numbers can likely be attributed to the greater size and longer residence time of Lake Superior. Distributions of plastic particles, characterized by size fraction and type, differed between nearshore and offshore samples and between samples collected in Eastern versus Western portion of the lake. No difference was detected between the paired net samples, indicating that single net sampling produces a representative estimate of microplastic particle abundance and distribution within a body of water. Most of the particles found were fibres (67%), and most were contained in the smallest classified size fraction (0.3-1 mm) indicative of the low population density and industrialization along the shores of Lake Superior. The most common type of polymer found was polyethylene (51%), followed by polypropylene (19%) which was expected given global plastics production is dominated by polyethylene, followed by polypropylene. This is also similar to results obtained from other studies. Types of plastic present, when separated by morphology and size, can help identify pollution sources which is a necessary step in plastic pollution management

Advanced trajectory tracking for UAVs using combined feedforward/feedback control design

Trajectory tracking is a major challenge for UAVs. The more complex the trajectory is, the more accurate tracking is required with minimum divergence from the trajectory. Apart from active trajectory tracking mechanisms, current solutions to accurate trajectory tracking in narrow areas require low speed motions. This paper presents a systematic design methodology using centralised feedforward/feedback control architecture for advanced trajectory tracking without compromising the speed of the vehicle. Using the norm as a measure for the design criteria, the proposed method proves fast tracking with no overshooting and less actuators energy compared with single degree-of-freedom feedback control method. The results are verified using simulations for two systems: a tri-rotor VTOL UAV (fully actuated system), and a quadrotor trainer (over-actuated system)

Crystallization And Preliminary X-Ray Analysis Of A Chitinase From The Fungal Pathogen Coccidioides Immitis

Chitinase is necessary for fungal growth and cell division and, therefore, is an ideal target for the design of inhibitors which may act as antifungal agents. A chitinase from the fungal pathogen Coccidioides immitis has been expressed as a fusion protein with gluathione-S-transferase (GST), which aids in purification. After cleavage from GST, chitinase was crystallized from 30% PEG 4000 in 0.1 M sodium acetate pH 4.6. The crystals have a tetragonal crystal lattice and belong to space group P4(1)2(1)2 or P4(3)2(1)2 and diffract to 2.2 Angstrom resolution. The unit-cell parameters are a = b = 91.2, c = 95.4 Angstrom; there is only one chitinase molecule in the asymmetric unit.National Institutes of Health GM 30048National Science Foundation MCB-9601096Foundation for ResearchWelch FoundationMolecular Bioscience

Does capitation affect patient satisfaction and prevalence of out-of-pocket payments in the insured? A propensity score analysis of Ghana's demographic and health survey data.

BACKGROUND: Ghana's National Health Insurance Scheme (NHIS) piloted capitation payment for primary care services in the Ashanti region from 2012 to 2017. Capitation was piloted as a means of cost containment but also to induce managed competition among health providers to improve the responsiveness of healthcare delivery. This study examined the effects of exposure to capitation on perceived health service quality and prevalence of out-of-pocket payments in NHIS insured clients. METHODS: Respondents of the 2014 Ghana Demographic and Health Survey (G-DHS) who reported having a valid NHIS card as their only form of health insurance coverage and made a health facility visit within the 6 months prior to the survey were used to assess the exposure effects of capitation on four outcomes: overall patient satisfaction, perceived friendliness of health staff, perceived adequacy of consultation time, and prevalence of out-of-pocket payments. We applied propensity score matching to balance distributions of covariates and to compare outcomes between exposed NHIS insured clients and their unexposed counterparts. RESULTS: NHIS insured clients exposed to capitation had 10 percentage points higher probability of encountering out-of-pocket payments than their unexposed counterparts (p = 0.009; 95% CI: 2.5-17.8%). There was no evidence of a difference between the two exposure groups for ratings of the three quality perceptions outcomes examined: overall patient satisfaction, difference 0.63 units (p = 0.46); perceived friendliness of health staff, difference 1.1% (p = 0.50); and perceived adequacy of consultation times, difference 0.1% (p = 0.96). CONCLUSION: In the Ghanaian context, our results suggest capitation was associated with a greater probability of out-of-pocket payments and no difference in perceived service quality. Future research should examine clinical quality of healthcare and how much out-of-pocket payment occurred under capitation

The differential short- and long-term effects of HIV-1 latency-reversing agents on T cell function

Despite the extraordinary success of HIV-1 antiretroviral therapy in prolonging life, infected individuals face lifelong therapy because of a reservoir of latently-infected cells that harbor replication competent virus. Recently, compounds have been identified that can reverse HIV-1 latency in vivo. These latency- reversing agents (LRAs) could make latently-infected cells vulnerable to clearance by immune cells, including cytolytic CD8+ T cells. We investigated the effects of two leading LRA classes on CD8+ T cell phenotype and function: the histone deacetylase inhibitors (HDACis) and protein kinase C modulators (PKCms). We observed that relative to HDACis, the PKCms induced much stronger T cell activation coupled with non-specific cytokine production and T cell proliferation. When examining antigen-specific CD8+ T cell function, all the LRAs except the HDACi Vorinostat reduced, but did not abolish, one or more measurements of CD8+ T cell function. Importantly, the extent and timing of these effects differed between LRAs. Panobinostat had detrimental effects within 10 hours of drug treatment, whereas the effects of the other LRAs were observed between 48 hours and 5 days. These observations suggest that scheduling of LRA and CD8+ T cell immunotherapy regimens may be critical for optimal clearance of the HIV-1 reservoir

Billion-atom Synchronous Parallel Kinetic Monte Carlo Simulations of Critical 3D Ising Systems

An extension of the synchronous parallel kinetic Monte Carlo (pkMC) algorithm developed by Martinez {\it et al} [{\it J.\ Comp.\ Phys.} {\bf 227} (2008) 3804] to discrete lattices is presented. The method solves the master equation synchronously by recourse to null events that keep all processors time clocks current in a global sense. Boundary conflicts are rigorously solved by adopting a chessboard decomposition into non-interacting sublattices. We find that the bias introduced by the spatial correlations attendant to the sublattice decomposition is within the standard deviation of the serial method, which confirms the statistical validity of the method. We have assessed the parallel efficiency of the method and find that our algorithm scales consistently with problem size and sublattice partition. We apply the method to the calculation of scale-dependent critical exponents in billion-atom 3D Ising systems, with very good agreement with state-of-the-art multispin simulations

Effector and Central Memory Poly-Functional CD4+ and CD8+ T Cells are Boosted upon ZOSTAVAX® Vaccination

ZOSTAVAX® is a live attenuated varicella-zoster virus (VZV) vaccine that is licensed for the protection of individuals ≥ 50 years against shingles, and its most common complication, post-herpetic neuralgia. While IFN responses increase upon vaccination, the quality of the T cell response has not been elucidated. By using polychromatic flow cytometry, we characterized the breadth, magnitude, and quality of ex vivo CD4+ and CD8+ T cell responses induced 3 – 4 weeks after ZOSTAVAX vaccination of healthy adults. We show, for the first time that the highest frequencies of VZV-specific CD4+ T cells were poly-functional CD154+IFNγ+IL-2+TNFα+ cells, which were boosted upon vaccination. The CD4+ T cells were broadly reactive to several VZV proteins, with IE63 ranking the highest amongst them in the fold-rise of poly-functional cells, followed by IE62, gB, ORF9, and gE. We identified a novel poly-functional ORF9-specific CD8+ T cell population in 62% of the subjects, and these were boosted upon vaccination. Poly-functional CD4+ and CD8+ T cells produced significantly higher levels of IFNγ, IL-2, and TNFα compared to mono-functional cells. After vaccination, a boost in the expression of IFN by poly-functional IE63-and ORF9-specific CD4+ T cells, and IFNγ, IL-2, and TNFα by ORF9-specific poly-functional CD8+ T cells was observed. Responding poly-functional T cells exhibited both effector (CCR7−CD45RA−CD45RO+), and central (CCR7+CD45RA−CD45RO+) memory phenotypes, which expressed comparable levels of cytokines. Altogether, our studies demonstrate that a boost in memory poly-functional CD4+ T cells, and ORF9-specific CD8+ T cells may contribute towards ZOSTAVAX efficacy

CD32 is expressed on cells with transcriptionally active HIV but does not enrich for HIV DNA in resting T cells

The persistence of HIV reservoirs, including latently infected, resting CD4+ T cells, is the major obstacle to cure HIV infection. CD32a expression was recently reported to mark CD4+ T cells harboring a replication-competent HIV reservoir during antiretroviral therapy (ART) suppression. We aimed to determine whether CD32 expression marks HIV latently or transcriptionally active infected CD4+ T cells. Using peripheral blood and lymphoid tissue of ART-treated HIV+ or SIV+ subjects, we found that most of the circulating memory CD32+ CD4+ T cells expressed markers of activation, including CD69, HLA-DR, CD25, CD38, and Ki67, and bore a TH2 phenotype as defined by CXCR3, CCR4, and CCR6. CD32 expression did not selectively enrich for HIV- or SIV-infected CD4+ T cells in peripheral blood or lymphoid tissue; isolated CD32+ resting CD4+ T cells accounted for less than 3% of the total HIV DNA in CD4+ T cells. Cell-associated HIV DNA and RNA loads in CD4+ T cells positively correlated with the frequency of CD32+ CD69+ CD4+ T cells but not with CD32 expression on resting CD4+ T cells. Using RNA fluorescence in situ hybridization, CD32 coexpression with HIV RNA or p24 was detected after in vitro HIV infection (peripheral blood mononuclear cell and tissue) and in vivo within lymph node tissue from HIV-infected individuals. Together, these results indicate that CD32 is not a marker of resting CD4+ T cells or of enriched HIV DNA–positive cells after ART; rather, CD32 is predominately expressed on a subset of activated CD4+ T cells enriched for transcriptionally active HIV after long-term ART

Vaccination with Ad5 Vectors Expands Ad5-Specific CD8+ T Cells without Altering Memory Phenotype or Functionality

Adenoviral (Ad) vaccine vectors represent both a vehicle to present a novel antigen to the immune system as well as restimulation of immune responses against the Ad vector itself. To what degree Ad-specific CD8(+) T cells are restimulated by Ad vector vaccination is unclear, although such knowledge would be important as vector-specific CD8(+) T cell expansion could potentially further limit Ad vaccine efficacy beyond Ad-specific neutralizing antibody alone.Here we addressed this issue by measuring human Adenovirus serotype 5 (Ad5)-specific CD8(+) T cells in recipients of the Merck Ad5 HIV-1 vaccine vector before, during, and after vaccination by multicolor flow cytometry. Ad5-specific CD8(+) T-cells were detectable in 95% of subjects prior to vaccination, and displayed primarily an effector-type functional profile and phenotype. Peripheral blood Ad5-specific CD8(+) T-cell numbers expanded after Ad5-HIV vaccination in all subjects, but differential expansion kinetics were noted in some baseline Ad5-neutralizing antibody (Ad5 nAb) seronegative subjects compared to baseline Ad5 nAb seropositive subjects. However, in neither group did vaccination alter polyfunctionality, mucosal targeting marker expression, or memory phenotype of Ad5-specific CD8(+) T-cells.These data indicate that repeat Ad5-vector administration in humans expands Ad5-specific CD8(+) T-cells without overtly affecting their functional capacity or phenotypic properties. This is a secondary analysis of samples collected during the 016 trial. Results of the Merck 016 trial safety and immunogenicity have been previously published in the journal of clinical infectious diseases [1].ClinicalTrials.gov NCT00849680[http://www.clinicaltrials.gov/show/NCT00849680]