59 research outputs found

    SLR Station Recovery, Center of Frame Motion, and Time Varying Gravity

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    Weekly station position estimates, beginning with 1993, are derived from the ITRF2008-based SLR processing of up to four satellites: Lageos 1, Lageos2, Starlette, and Stella. Helmert parameters obtained from c omparison of weekly SLR station positions and the a-priori SLRF2008 station complement are evaluated for geocenter motion and scale. Two me thods for modeling time varying gravity are employed in the SLR satel lite POD processing, with GGM03S serving as the static gravity field. Both methods forward model atmosphere gravity derived from 6-hour ECM WF pressure data. The standard approach applies an annual 20x20 field estimated from 4 years of GRACE data, and the IERS2003 recommended linear rates for C20, C30, C40, C21, and S21. The alternate approach us es a new set of low-order/degree 4x4 coefficients estimated weekly fr om SLR & DORIS processing to 10 satellites from 1993-2012. This exper imental tvg4x4 model has been shown to improve the TOPEX, Jason-1, and Jason-2 altimeter satellite orbits,. In this paper we apply the more detailed time-variable gravity modeling to the SLR satellite POD pro cessing and subsequent reference frame analyses. For this study we will evaluate the orbit differences (periodic and secular) for the satel lites concerned, characterize the impact on the station coordinate solutions, and the impact on reference frame parameters (geocenter and s cale)

    Clinical Skills Development in the Virtual Learning Environment: Adapting to a New World

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    The rapid transition to distance learning in response to the unexpected SARS-CoV-2/COVID-19 pandemic led to disruption of clinical skills development, which are typically conducted face-to-face. Consequently, faculty adapted their courses, using a multitude of active learning modalities, to meet student learning objectives in the didactic and experiential settings. Strategies and considerations to implement innovative delivery methods and address potential challenges are elucidated. Furthermore, integration of a layered learning approach may allow for more broad perspectives and allow additional interactions and feedback, which is especially necessary in the virtual environment.https://digitalcommons.chapman.edu/pharmacy_books/1025/thumbnail.jp

    Prevalence of selected infectious disease agents in stray cats in Catalonia, Spain

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    The objective of the current study was to investigate the prevalence rates of the following infectious agents in 116 stray cats in the Barcelona area of Spain: Anaplasma phagocytophilum, Bartonella species, Borrelia burgdorferi, Chlamydia felis, Dirofilaria immitis, Ehrlichia species, feline calicivirus (FCV), feline herpesvirus-1 (FHV-1), feline leukaemia virus (FeLV), feline immunodeficiency virus (FIV), haemoplasmas, Mycoplasma species and Rickettsia species. Serum antibodies were used to estimate the prevalence of exposure to A phagocytophilum, Bartonella species, B burgdorferi, Ehrlichia species and FIV; serum antigens were used to assess for infection by D immitis and FeLV; and molecular assays were used to amplify nucleic acids of Anaplasma species, Bartonella species, C felis, D immitis, Ehrlichia species, FCV, FHV-1, haemoplasmas, Mycoplasma species and Rickettsia species from blood and nasal or oral swabs. Of the 116 cats, 63 (54.3%) had evidence of infection by Bartonella species, FeLV, FIV or a haemoplasma. Anaplasma species, Ehrlichia species or Rickettsia species DNA was not amplified from these cats. A total of 18/116 cats (15.5%) were positive for FCV RNA (six cats), Mycoplasma species DNA (six cats), FHV-1 DNA (three cats) or C felis DNA (three cats). This study documents that shelter cats in Catalonia are exposed to many infectious agents with clinical and zoonotic significance, and that flea control is indicated for cats in the region

    Taxon-Specific Aerosolization of Bacteria and Viruses In an Experimental Ocean-Atmosphere Mesocosm

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    Ocean-derived, airborne microbes play important roles in Earth’s climate system and human health, yet little is known about factors controlling their transfer from the ocean to the atmosphere. Here, we study microbiomes of isolated sea spray aerosol (SSA) collected in a unique ocean–atmosphere facility and demonstrate taxon-specific aerosolization of bacteria and viruses. These trends are conserved within taxonomic orders and classes, and temporal variation in aerosolization is similarly shared by related taxa. We observe enhanced transfer into SSA of Actinobacteria, certain Gammaproteobacteria, and lipid-enveloped viruses; conversely, Flavobacteriia, some Alphaproteobacteria, and Caudovirales are generally under-represented in SSA. Viruses do not transfer to SSA as efficiently as bacteria. The enrichment of mycolic acid-coated Corynebacteriales and lipid-enveloped viruses (inferred from genomic comparisons) suggests that hydrophobic properties increase transport to the sea surface and SSA. Our results identify taxa relevant to atmospheric processes and a framework to further elucidate aerosolization mechanisms influencing microbial and viral transport pathways

    Consequences and Utility of the Zinc-Dependent Metalloprotease Activity of Anthrax Lethal Toxin

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    Anthrax is caused by the gram-positive bacterium Bacillus anthracis. The pathogenesis of this disease is dependent on the presence of two binary toxins, edema toxin (EdTx) and lethal toxin (LeTx). LeTx, the major virulence factor contributing to anthrax, contains the effector moiety lethal factor (LF), a zinc-dependent metalloprotease specific for targeting mitogen-activated protein kinase kinases. This review will focus on the protease-specific activity and function of LF, and will include a discussion on the implications and consequences of this activity, both in terms of anthrax disease, and how this activity can be exploited to gain insight into other pathologic conditions

    The global distribution and diversity of protein vaccine candidate antigens in the highly virulent Streptococcus pnuemoniae serotype 1

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    Serotype 1 is one of the most common causes of pneumococcal disease worldwide. Pneumococcal protein vaccines are currently being developed as an alternate intervention strategy to pneumococcal conjugate vaccines. Pre-requisites for an efficacious pneumococcal protein vaccine are universal presence and minimal variation of the target antigen in the pneumococcal population, and the capability to induce a robust human immune response. We used in silico analysis to assess the prevalence of seven protein vaccine candidates (CbpA, PcpA, PhtD, PspA, SP0148, SP1912, SP2108) among 445 serotype 1 pneumococci from 26 different countries, across four continents. CbpA (76%), PspA (68%), PhtD (28%), PcpA (11%) were not universally encoded in the study population, and would not provide full coverage against serotype 1. PcpA was widely present in the European (82%), but not in the African (2%) population. A multi-valent vaccine incorporating CbpA, PcpA, PhtD and PspA was predicted to provide coverage against 86% of the global population. SP0148, SP1912 and SP2108 were universally encoded and we further assessed their predicted amino acid, antigenic and structural variation. Multiple allelic variants of these proteins were identified, different allelic variants dominated in different continents; the observed variation was predicted to impact the antigenicity and structure of two SP0148 variants, one SP1912 variant and four SP2108 variants, however these variants were each only present in a small fraction of the global population (<2%). The vast majority of the observed variation was predicted to have no impact on the efficaciousness of a protein vaccine incorporating a single variant of SP0148, SP1912 and/or SP2108 from S. pneumoniae TIGR4. Our findings emphasise the importance of taking geographic differences into account when designing global vaccine interventions and support the continued development of SP0148, SP1912 and SP2108 as protein vaccine candidates against this important pneumococcal serotype

    Pneumococcal lineages associated with serotype replacement and antibiotic resistance in childhood invasive pneumococcal disease in the post-PCV13 era: an international whole-genome sequencing study

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    Background: Invasive pneumococcal disease remains an important health priority owing to increasing disease incidence caused by pneumococci expressing non-vaccine serotypes. We previously defined 621 Global Pneumococcal Sequence Clusters (GPSCs) by analysing 20 027 pneumococcal isolates collected worldwide and from previously published genomic data. In this study, we aimed to investigate the pneumococcal lineages behind the predominant serotypes, the mechanism of serotype replacement in disease, as well as the major pneumococcal lineages contributing to invasive pneumococcal disease in the post-vaccine era and their antibiotic resistant traits. Methods: We whole-genome sequenced 3233 invasive pneumococcal disease isolates from laboratory-based surveillance programmes in Hong Kong (n=78), Israel (n=701), Malawi (n=226), South Africa (n=1351), The Gambia (n=203), and the USA (n=674). The genomes represented pneumococci from before and after pneumococcal conjugate vaccine (PCV) introductions and were from children younger than 3 years. We identified predominant serotypes by prevalence and their major contributing lineages in each country, and assessed any serotype replacement by comparing the incidence rate between the pre-PCV and PCV periods for Israel, South Africa, and the USA. We defined the status of a lineage as vaccine-type GPSC (≥50% 13-valent PCV [PCV13] serotypes) or non-vaccine-type GPSC (>50% non-PCV13 serotypes) on the basis of its initial serotype composition detected in the earliest vaccine period to measure their individual contribution toward serotype replacement in each country. Major pneumococcal lineages in the PCV period were identified by pooled incidence rate using a random effects model. Findings: The five most prevalent serotypes in the PCV13 period varied between countries, with only serotypes 5, 12F, 15B/C, 19A, 33F, and 35B/D common to two or more countries. The five most prevalent serotypes in the PCV13 period varied between countries, with only serotypes 5, 12F, 15B/C, 19A, 33F, and 35B/D common to two or more countries. These serotypes were associated with more than one lineage, except for serotype 5 (GPSC8). Serotype replacement was mainly mediated by expansion of non-vaccine serotypes within vaccine-type GPSCs and, to a lesser extent, by increases in non-vaccine-type GPSCs. A globally spreading lineage, GPSC3, expressing invasive serotypes 8 in South Africa and 33F in the USA and Israel, was the most common lineage causing non-vaccine serotype invasive pneumococcal disease in the PCV13 period. We observed that same prevalent non-vaccine serotypes could be associated with distinctive lineages in different countries, which exhibited dissimilar antibiotic resistance profiles. In non-vaccine serotype isolates, we detected significant increases in the prevalence of resistance to penicillin (52 [21%] of 249 vs 169 [29%] of 575, p=0·0016) and erythromycin (three [1%] of 249 vs 65 [11%] of 575, p=0·0031) in the PCV13 period compared with the pre-PCV period. Interpretation: Globally spreading lineages expressing invasive serotypes have an important role in serotype replacement, and emerging non-vaccine serotypes associated with different pneumococcal lineages in different countries might be explained by local antibiotic-selective pressures. Continued genomic surveillance of the dynamics of the pneumococcal population with increased geographical representation in the post-vaccine period will generate further knowledge for optimising future vaccine design. Funding: Bill & Melinda Gates Foundation, Wellcome Sanger Institute, and the US Centers for Disease Control.Fil: Lo, Stephanie W.. Wellcome Sanger Institute; Reino UnidoFil: Gladstone, Rebecca A.. Wellcome Sanger Institute; Reino UnidoFil: van Tonder, Andries J.. Wellcome Sanger Institute; Reino UnidoFil: Lees, John A.. University Of New York. School Of Medicine; Estados UnidosFil: du Plessis, Mignon. National Institute For Communicable Diseases; SudáfricaFil: Benisty, Rachel. Ben Gurion University of the Negev; IsraelFil: Givon Lavi, Noga. Ben Gurion University of the Negev; IsraelFil: Hawkins, Paulina A.. University of Emory. Rollins School of Public Health; Estados UnidosFil: Cornick, Jennifer E.. Malawi liverpool wellcome trust; MalauiFil: Kwambana Adams, Brenda. University College London; Estados UnidosFil: Law, Pierra Y.. University of Hong Kong; ChinaFil: Ho, Pak Leung. University of Hong Kong; ChinaFil: Antonio, Martin. Medical Research Council Unit The Gambia; GambiaFil: Everett, Dean B.. University of Edinburgh; Reino UnidoFil: Dagan, Ron. Ben Gurion University of the Negev; IsraelFil: Von Gottberg, Anne. National Institute For Communicable Diseases; SudáfricaFil: Klugman, Keith P.. University of Emory. Rollins School of Public Health; Estados UnidosFil: McGee, Lesley. Centers for Disease Control and Prevention; Estados UnidosFil: Breiman, Robert F.. University of Emory. Rollins School of Public Health; Estados UnidosFil: Bentley, Stephen D.. Wellcome Sanger Institute; Reino UnidoFil: Brooks, Abdullah W.. The Global Pneumococcal Sequencing Consortium; Reino UnidoFil: Corso, Alejandra. The Global Pneumococcal Sequencing Consortium; Reino Unido. Dirección Nacional de Institutos de Investigación. Administración Nacional de Laboratorios e Institutos de Salud. Instituto Nacional de Enfermedades Infecciosas. Área de Antimicrobianos; ArgentinaFil: Davydov, Alexander. The Global Pneumococcal Sequencing Consortium; Reino UnidoFil: Maguire, Alison. The Global Pneumococcal Sequencing Consortium; Reino UnidoFil: Pollard, Andrew. The Global Pneumococcal Sequencing Consortium; Reino UnidoFil: Kiran, Anmol. The Global Pneumococcal Sequencing Consortium; Reino UnidoFil: Skoczynska, Anna. The Global Pneumococcal Sequencing Consortium; Reino UnidoFil: Moiane, Benild. The Global Pneumococcal Sequencing Consortium; Reino UnidoFil: Beall, Bernard. The Global Pneumococcal Sequencing Consortium; Reino UnidoFil: Sigauque, Betuel. The Global Pneumococcal Sequencing Consortium; Reino UnidoFil: Aanensen, David. The Global Pneumococcal Sequencing Consortium; Reino UnidoFil: Lehmann, Deborah. The Global Pneumococcal Sequencing Consortium; Reino UnidoFil: Faccone, Diego Francisco. Dirección Nacional de Institutos de Investigación. Administración Nacional de Laboratorios e Institutos de Salud. Instituto Nacional de Enfermedades Infecciosas. Área de Antimicrobianos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Global emergence and population dynamics of divergent serotype 3 CC180 pneumococci

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    Streptococcus pneumoniae serotype 3 remains a significant cause of morbidity and mortality worldwide, despite inclusion in the 13-valent pneumococcal conjugate vaccine (PCV13). Serotype 3 increased in carriage since the implementation of PCV13 in the USA, while invasive disease rates remain unchanged. We investigated the persistence of serotype 3 in carriage and disease, through genomic analyses of a global sample of 301 serotype 3 isolates of the Netherlands3–31 (PMEN31) clone CC180, combined with associated patient data and PCV utilization among countries of isolate collection. We assessed phenotypic variation between dominant clades in capsule charge (zeta potential), capsular polysaccharide shedding, and susceptibility to opsonophagocytic killing, which have previously been associated with carriage duration, invasiveness, and vaccine escape. We identified a recent shift in the CC180 population attributed to a lineage termed Clade II, which was estimated by Bayesian coalescent analysis to have first appeared in 1968 [95% HPD: 1939–1989] and increased in prevalence and effective population size thereafter. Clade II isolates are divergent from the pre-PCV13 serotype 3 population in non-capsular antigenic composition, competence, and antibiotic susceptibility, the last of which resulting from the acquisition of a Tn916-like conjugative transposon. Differences in recombination rates among clades correlated with variations in the ATP-binding subunit of Clp protease, as well as amino acid substitutions in the comCDE operon. Opsonophagocytic killing assays elucidated the low observed efficacy of PCV13 against serotype 3. Variation in PCV13 use among sampled countries was not independently correlated with the CC180 population shift; therefore, genotypic and phenotypic differences in protein antigens and, in particular, antibiotic resistance may have contributed to the increase of Clade II. Our analysis emphasizes the need for routine, representative sampling of isolates from disperse geographic regions, including historically under-sampled areas. We also highlight the value of genomics in resolving antigenic and epidemiological variations within a serotype, which may have implications for future vaccine development
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