Figures of Merit for Wind and Solar PV Integration in Electricity Grids

349-357In future electrical grids, high levels of Variable Renewable Energy (VRE) penetration including solar photovoltaics (PV) and wind energy is expected. This poses a challenge in system operation and planning especially in balancing electricity demand and supply. This paper examines figures of merit for wind and solar integration in electricity grids. Quantitative tools such as load duration curves, correlation analyses, and the Fourier transform were used to study the intermittency/variability of wind and solar PV power. Time series data on power production from the European Network of Transmission System Operators for Electricity (ENTSO-E), and Réseau de Transport d'Électricité (RTE) were used for the analyses. The analyses illustrate that despite the valuable amount of energy that can be obtained from wind and solar PV, these energy sources cannot be used as baseload power supply. Solar PV power is available for approximately 50% of the time year-round. Wind power output on the other hand can reach very small magnitudes of just a few megawatts several times in a year. More to that, wind is positively correlated over long distances, even exceeding 3000 km and aggregating wind fleets over a large geographic area might not guarantee continuous availability of wind power. Nonetheless, these sources can still be integrated in electricity grids in high proportions, provided intermittency mitigation options such as energy storage, curtailment, and demand-response are implemented

Serological Evidence of Discrete Spatial Clusters of Plasmodium falciparum Parasites

BACKGROUND: Malaria transmission may be considered to be homogenous with well-mixed parasite populations (as in the classic Ross/Macdonald models). Marked fine-scale heterogeneity of transmission has been observed in the field (i.e., over a few kilometres), but there are relatively few data on the degree of mixing. Since the Plasmodium falciparum Erythrocyte Membrane Protein 1 (PfEMP1) is highly polymorphic, the host's serological responses may be used to infer exposure to parasite sub-populations. METHODS AND FINDINGS: We measured the antibody responses to 46 individual PfEMP1 domains at four time points among 450 children in Kenya, and identified distinct spatial clusters of antibody responses to individual domains. 35 domains showed strongly significant sero-clusters at p = 0.001. Individuals within the high transmission hotspot showed the greatest diversity of anti-PfEMP1 responses. Individuals outside the hotspot had a less diverse range of responses, even if as individuals they were at relatively intense exposure. CONCLUSIONS: We infer that antigenically distinct sub-populations of parasites exist on a fine spatial scale in a study area of rural Kenya. Further studies should examine antigenic variation over longer periods of time and in different study areas

Implementing the package of CDC and WHO recommended linkage services: Methods, outcomes, and costs of the Bukoba Tanzania Combination Prevention Evaluation peer-delivered, linkage case management program, 2014-2017

Although several studies have evaluated one or more linkage services to improve early enrollment in HIV care in Tanzania, none have evaluated the package of linkage services recommended by the Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO). We describe the uptake of each component of the CDC/WHO recommended package of linkage services, and early enrollment in HIV care and antiretroviral therapy (ART) initiation among persons with HIV who participated in a peer-delivered, linkage case management (LCM) program implemented in Bukoba, Tanzania, October 2014 –May 2017. Of 4206 participants (88% newly HIV diagnosed), most received recommended services including counseling on the importance of early enrollment in care and ART (100%); escort by foot or car to an HIV care and treatment clinic (CTC) (83%); treatment navigation at a CTC (94%); telephone support and appointment reminders (77% among clients with cellphones); and counseling on HIV-status disclosure and partner/family testing (77%), and on barriers to care (69%). During three periods with different ART-eligibility thresholds [CD4<350 (Oct 2014 –Dec 2015, n = 2233), CD4≤500 (Jan 2016 –Sept 2016, n = 1221), and Test & Start (Oct 2016 –May 2017, n = 752)], 90%, 96%, and 97% of clients enrolled in HIV care, and 47%, 67%, and 86% of clients initiated ART, respectively, within three months of diagnosis. Of 463 LCM clients who participated in the last three months of the rollout of Test & Start, 91% initiated ART. Estimated per-client cost was $44 United States dollars (USD) for delivering LCM services in communities and facilities overall, and$18 USD for a facility-only model with task shifting. Well accepted by persons with HIV, peer-delivered LCM services recommended by CDC and WHO can achieve near universal early ART initiation in the Test & Start era at modest cost and should be considered for implementation in facilities and communities experiencing <90% early enrollment in ART care

Surface Co-Expression of Two Different PfEMP1 Antigens on Single Plasmodium falciparum-Infected Erythrocytes Facilitates Binding to ICAM1 and PECAM1

The Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) antigens play a major role in cytoadhesion of infected erythrocytes (IE), antigenic variation, and immunity to malaria. The current consensus on control of variant surface antigen expression is that only one PfEMP1 encoded by one var gene is expressed per cell at a time. We measured var mRNA transcript levels by real-time Q-PCR, analysed var gene transcripts by single-cell FISH and directly compared these with PfEMP1 antigen surface expression and cytoadhesion in three different antibody-selected P. falciparum 3D7 sub-lines using live confocal microscopy, flow cytometry and in vitro adhesion assays. We found that one selected parasite sub-line simultaneously expressed two different var genes as surface antigens, on single IE. Importantly, and of physiological relevance to adhesion and malaria pathogenesis, this parasite sub-line was found to bind both CD31/PECAM1 and CD54/ICAM1 and to adhere twice as efficiently to human endothelial cells, compared to infected cells having only one PfEMP1 variant on the surface. These new results on PfEMP1 antigen expression indicate that a re-evaluation of the molecular mechanisms involved in P. falciparum adhesion and of the accepted paradigm of absolutely mutually exclusive var gene transcription is required

Self-catalyzed synthesis of a nano-capsule and its application as a heterogeneous RCMP catalyst and nano-reactor

A novel polymeric nano-capsule bearing quaternary ammonium iodide (QAI) groups on both the outer and inner surfaces of the shell was synthesized via self-catalyzed polymerization-induced self-assembly (PISA). Because QAI works as a catalyst of reversible complexation mediated living radical polymerization (RCMP), the obtained nano-capsule was exploited as a dual RCMP catalyst based on the outer and inner QAI groups. Benefitting from the outer QAI groups, the nano-capsule served as a supported heterogeneous RCMP catalyst with good recyclability to generate polymers outside the nano-capsule. Benefitting from the inner QAI groups, the nano-capsule served as a nano-reactor to generate polymers inside the nano-capsule. The nano-capsule served as a substrate-sorting nano-reactor based on the selective diffusivity of small molecules and polymers through the shell by their sizes. Namely, large molecules (polymers) once generated in the nano-reactor are not permeable through the shell, enabling the entrapment of the generated polymers in the nano-capsule. A homopolymer, an amphiphilic block copolymer, and a multi-polarity and multielemental block copolymer were synthesized and entrapped in the nano-capsule.National Research Foundation (NRF)Published versionThis work was supported by the National Research Foundation (NRF) Investigatorship in Singapore (NRF-NRFI05-2019-0001)

A semi-automated multiplex high-throughput assay for measuring IgG antibodies against <em>Plasmodium falciparum</em> erythrocyte membrane protein 1 (PfEMP1) domains in small volumes of plasma

BACKGROUND: The level of antibodies against PfEMP1 is routinely quantified by the conventional microtitre enzyme-linked immunosorbent assay (ELISA). However, ELISA only measures one analyte at a time and requires a relatively large plasma volume if the complete antibody profile of the sample is to be obtained. Furthermore, assay-to-assay variation and the problem of storage of antigen can influence ELISA results. The bead-based assay described here uses the BioPlex(100 )(BioRad, Hercules, CA, USA) system which can quantify multiple antibodies simultaneously in a small plasma volume. METHODS: A total of twenty nine PfEMP1 domains were PCR amplified from 3D7 genomic DNA, expressed in the Baculovirus system and purified by metal-affinity chromatography. The antibody reactivity level to the recombinant PfEMP1 proteins in human hyper-immune plasma was measured by ELISA. In parallel, these recombinant PfEMP1 proteins were covalently coupled onto beads each having its own unique detection signal and the human hyper-immune plasma reactivity was detected for each individual protein using a BioPlex(100 )system. Protein-coupled beads were analysed at two time points seven months apart, before and after lyophilization and the results compared to determine the effect of storage and lyophilization respectively on the beads. Multiplexed protein-coupled beads from twenty eight unique bead populations were evaluated on the BioPlex(100 )system against pooled human hyper-immune plasma before and after lyophilization. RESULTS: The bead(-)based assay was sensitive, accurate and reproducible. Four recombinant PfEMP1 proteins C17, D5, D9 and D12, selected on the basis that they showed a spread of median fluorescent intensity (MFI) values from low to high when analysed by the bead-based assay were analysed by ELISA and the results from both analyses were highly correlated. The Spearman's rank correlation coefficients (Rho) were ≥ 0.86, (P < 0.0001) for all comparisons. Bead-based assays gave similar results regardless of whether they were performed on individual beads or on multiplexed beads; lyophilization had no impact on the assay performance. Spearman's rank correlation coefficients (Rho) were ≥ 0.97, (P < 0.0001) for all comparisons. Importantly, the reactivity of protein-coupled non-lyophilized beads decreased with long term storage at 4°C in the dark. CONCLUSION: Using this lyophilized multiplex assay, antibody reactivity levels to twenty eight different recombinant PfEMP1 proteins were simultaneously measured using a single microliter of plasma. Thus, the assay reported here provides a useful tool for rapid and efficient quantification of antibody reactivity against PfEMP1 variants in human plasma

A semi-automated multiplex high-throughput assay for measuring IgG antibodies against erythrocyte membrane protein 1 (PfEMP1) domains in small volumes of plasma-5

Asma (white bars) and a pooled naïve plasma from Danish donors (black bars). The results were expressed as median fluorescent intensity (MFI).<p><b>Copyright information:</b></p><p>Taken from "A semi-automated multiplex high-throughput assay for measuring IgG antibodies against erythrocyte membrane protein 1 (PfEMP1) domains in small volumes of plasma"</p><p>http://www.malariajournal.com/content/7/1/108</p><p>Malaria Journal 2008;7():108-108.</p><p>Published online 12 Jun 2008</p><p>PMCID:PMC2435541.</p><p></p

A semi-automated multiplex high-throughput assay for measuring IgG antibodies against erythrocyte membrane protein 1 (PfEMP1) domains in small volumes of plasma-0

Asma (white bars) and a pooled naïve plasma from Danish donors (black bars). The results were expressed as median fluorescent intensity (MFI).<p><b>Copyright information:</b></p><p>Taken from "A semi-automated multiplex high-throughput assay for measuring IgG antibodies against erythrocyte membrane protein 1 (PfEMP1) domains in small volumes of plasma"</p><p>http://www.malariajournal.com/content/7/1/108</p><p>Malaria Journal 2008;7():108-108.</p><p>Published online 12 Jun 2008</p><p>PMCID:PMC2435541.</p><p></p