420 research outputs found

    Revisiting cell-particle association in vitro: A quantitative method to compare particle performance

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    Nanoengineering has the potential to revolutionize medicine by designing drug delivery systems that are both efficacious and highly selective. Determination of the affinity between cell lines and nanoparticles is thus of central importance, both to enable comparison of particles and to facilitate prediction of in vivo response. Attempts to compare particle performance can be dominated by experimental artifacts (including settling effects) or variability in experimental protocol. Instead, qualitative methods are generally used, limiting the reusability of many studies. Herein, we introduce a mathematical model-based approach to quantify the affinity between a cell-particle pairing, independent of the aforementioned confounding artifacts. The analysis presented can serve as a quantitative metric of the stealth, fouling, and targeting performance of nanoengineered particles in vitro. We validate this approach using a newly created in vitro dataset, consisting of seven different disulfide-stabilized poly(methacrylic acid) particles ranging from ~100 to 1000 nm in diameter that were incubated with three different cell lines (HeLa, THP-1, and RAW 264.7). We further expanded this dataset through the inclusion of previously published data and use it to determine which of five mathematical models best describe cell-particle association. We subsequently use this model to perform a quantitative comparison of cell-particle association for cell-particle pairings in our dataset. This analysis reveals a more complex cell-particle association relationship than a simplistic interpretation of the data, which erroneously assigns high affinity for all cell lines examined to large particles. Finally, we provide an online tool (http://bionano.xyz/estimator), which allows other researchers to easily apply this modeling approach to their experimental results

    Perancangan Sistem K3 Dalam Aktivitas Praktikum Teknik Industri Berdasarkan Metode Swift (The Structured What-If Analysis) di Teknik Industri Studi Kasus: Laboratorium Teknik Industri, Lantai 3 Gedung H, Universitas Muhammadiyah Surakarta)

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    Risiko tentang bahaya kerja tidak hanya berada diperusahaan atau digedung-gedung besar tetapi segala tempat yang beresiko menimbulkan kecelakaan kerja tentunya perlu terstandarisasi yang mengacu pada standarisasi K3 demi mendapatkan kenyamanan dan keamanan. Saat ini banyak kita jumpai karyawan di perusahaan yang kurang menyadari terhadap penerapan sistem K3, hal semacam ini tidak lain dikarenakan SDM yang kurang mendukung. Sebagai sarana untuk mulai mengenalkan K3 kedalam sistem edukasi tentunya yang pertama adalah memasukkan mata kuliah K3 didalam perkuliahan, selain itu untuk memperdalam pemahaman mahasiswa bisa juga kita langsung mempraktikkan sistem K3 tersebut didalam sebuah kampus dengan cara membuat bangunan kampus standar dengan detail-detail K3. Sehingga mahasiswa akan paham lebih mendalam dengan adanya praktik langsung didalam kampus melalui Standar Operasional Sistem yang sudah menyerupai sebuah perusahaan. Faktor kecelakaan yang terjadi di laboratorium komputer dan laboratorium PTI diakibatkan karena alat pelindung diri (APD) yang tidak ditaati oleh mahasiswa, melanggar larangan/ peraturan yang telah ditetapkan, dan ketidaktahuan mahasiswa akan pentingnya K3. Metoda SWIFT merupakan metode identifikasi bahaya yang memperkirakan bahaya yang timbul dan mempersiapkan daftar periksa yang dapat mengungkapkan kemungkinan bahaya yang terkandung dalam unit proses. Analisis dilakukan dengan penentuan prioritas bahaya yang terjadi untuk dibuat suatu usulan perbaikan. Tujuan penelitian ini yaitu memberikan usulan perbaikan sistem manajemen keselamatan dan kesehatan kerja pada Teknik Industri menentukan sistem Standar Operational Procedure (SOP) yang akan diamati, mengidentifikasi potensi bahaya yang mungkin terjadi di stasiun kerja menggunakan kata kunci checklist, dan membuat usulan perbaikan

    Evidence for the impact of interventions and medicines reconciliation on problematic polypharmacy in the UK: A rapid review of systematic reviews

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    This was a rapid review of systematic reviews (SRs) on problematic polypharmacy (PP) in the UK. The commissioner-defined topics were burden of PP, interventions to reduce PP, implementation activities to increase uptake of interventions, and efficient handover between primary and secondary care to reduce PP. Databases including Medline were searched to June 2019, SR quality was assessed using AMSTAR-2 (A MeaSurement Tool to Assess systematic Reviews) and a narrative synthesis was undertaken. Except for burden of PP (SRs had to include UK studies), there were no restrictions on country, location of care or outcomes. Nine SRs were included. On burden, three SRs (including six UK studies) found a high prevalence of polypharmacy in long term care. PP was associated with mortality, although unclear if causal, with no information on costs or health consequences. On interventions, six reviews (27 UK studies) found that interventions can reduce PP, but no effects on health outcomes. On handover between primary and secondary care, one review (two UK studies) found medicine reconciliation activities to reduce medication discrepancies at care transitions reduce PP, although the evidence is low quality. No SRs on implementation activities to increase uptake of interventions were found. SR quality was variable, with some concerns regarding meta-analysis methods. Evidence of the extent of PP in the UK, and what interventions to address it are effective in the UK, is limited. Future UK research is needed on the prevalence and consequences of PP, the effectiveness and cost-effectiveness of interventions to reduce PP, and barriers and activities to ensure uptake

    Fungal entomopathogens: new insights on their ecology

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    An important mechanism for insect pest control should be the use of fungal entomopathogens. Even though these organisms have been studied for more than 100 y, their effective use in the field remains elusive. Recently, however, it has been discovered that many of these entomopathogenic fungi play additional roles in nature. They are endophytes, antagonists of plant pathogens, associates with the rhizosphere, and possibly even plant growth promoting agents. These findings indicate that the ecological role of these fungi in the environment is not fully understood and limits our ability to employ them successfully for pest management. In this paper, we review the recently discovered roles played by many entomopathogenic fungi and propose new research strategies focused on alternate uses for these fungi. It seems likely that these agents can be used in multiple roles in protecting plants from pests and diseases and at the same time promoting plant growth

    Insertion of an Esterase Gene into a Specific Locust Pathogen (Metarhizium acridum) Enables It to Infect Caterpillars

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    An enduring theme in pathogenic microbiology is poor understanding of the mechanisms of host specificity. Metarhizium is a cosmopolitan genus of invertebrate pathogens that contains generalist species with broad host ranges such as M. robertsii (formerly known as M. anisopliae var. anisopliae) as well as specialists such as the acridid-specific grasshopper pathogen M. acridum. During growth on caterpillar (Manduca sexta) cuticle, M. robertsii up-regulates a gene (Mest1) that is absent in M. acridum and most other fungi. Disrupting M. robertsii Mest1 reduced virulence and overexpression increased virulence to caterpillars (Galleria mellonella and M. sexta), while virulence to grasshoppers (Melanoplus femurrubrum) was unaffected. When Mest1 was transferred to M. acridum under control of its native M. robertsii promoter, the transformants killed and colonized caterpillars in a similar fashion to M. robertsii. MEST1 localized exclusively to lipid droplets in M. robertsii conidia and infection structures was up-regulated during nutrient deprivation and had esterase activity against lipids with short chain fatty acids. The mobilization of stored lipids was delayed in the Mest1 disruptant mutant. Overall, our results suggest that expression of Mest1 allows rapid hydrolysis of stored lipids, and promotes germination and infection structure formation by M. robertsii during nutrient deprivation and invasion, while Mest1 expression in M. acridum broadens its host range by bypassing the regulatory signals found on natural hosts that trigger the mobilization of endogenous nutrient reserves. This study suggests that speciation in an insect pathogen could potentially be driven by host shifts resulting from changes in a single gene

    Safe Parallelism: Compiler Analysis Techniques for Ada and OpenMP

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    There is a growing need to support parallel computation in Ada to cope with the performance requirements of the most advanced functionalities of safety-critical systems. In that regard, the use of parallel programming models is paramount to exploit the benefits of parallelism. Recent works motivate the use of OpenMP for being a de facto standard in high-performance computing for programming shared memory architectures. These works address two important aspects towards the introduction of OpenMP in Ada: the compatibility of the OpenMP syntax with the Ada language, and the interoperability of the OpenMP and the Ada runtimes, demonstrating that OpenMP complements and supports the structured parallelism approach of the tasklet model. This paper addresses a third fundamental aspect: functional safety from a compiler perspective. Particularly, it focuses on race conditions and considers the fine-grain and unstructured capabilities of OpenMP. Hereof, this paper presents a new compiler analysis technique that: (1) identifies potential race conditions in parallel Ada programs based on OpenMP or Ada tasks or both, and (2) provides solutions for the detected races.This work was supported by the Spanish Ministry of Science and Innovation under contract TIN2015-65316-P, and by the FCT (Portuguese Foundation for Science and Technology) within the CISTER Research Unit (CEC/04234).Peer ReviewedPostprint (author's final draft

    Reductions in the Prevalence and Incidence of Geohelminth Infections following a City-wide Sanitation Program in a Brazilian Urban Centre

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    In the city of Salvador, a large urban centre in Northeast Brazil, a city-wide sanitation intervention started in 1997, aiming to improve the sewerage coverage of households from 26% to 80%. Our aim was to study the impact of the intervention on the prevalence and incidence of geohelminths in the school-aged population. The longitudinal study comprised two cohorts: from the beginning of 1997 to 1998, where data was collected before the intervention, and at the end of 2003 to 2004, after the intervention. Copro-parasitological examinations were carried out on every individual from both cohorts, at the start and nine months later. Demographic, socio-economic, and environmental data were collected using semi-structured questionnaires. The variables utilized to demonstrate the effects of intervention, when utilized together in a multivariate model, accounted for a 100% observed reduction in the prevalence ratio (PR) and incidence ratio (IR). As well as proving that the variables associated with the effect of the program intervention were mediators in this reduction, the reduction in the PR and IR between these periods demonstrated that modifications to the urban environment, particularly those associated with sanitary sewage systems, affected the health of the population, significantly reducing the prevalence of geohelminths

    Genome Sequencing and Comparative Transcriptomics of the Model Entomopathogenic Fungi Metarhizium anisopliae and M. acridum

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    Metarhizium spp. are being used as environmentally friendly alternatives to chemical insecticides, as model systems for studying insect-fungus interactions, and as a resource of genes for biotechnology. We present a comparative analysis of the genome sequences of the broad-spectrum insect pathogen Metarhizium anisopliae and the acridid-specific M. acridum. Whole-genome analyses indicate that the genome structures of these two species are highly syntenic and suggest that the genus Metarhizium evolved from plant endophytes or pathogens. Both M. anisopliae and M. acridum have a strikingly larger proportion of genes encoding secreted proteins than other fungi, while ∼30% of these have no functionally characterized homologs, suggesting hitherto unsuspected interactions between fungal pathogens and insects. The analysis of transposase genes provided evidence of repeat-induced point mutations occurring in M. acridum but not in M. anisopliae. With the help of pathogen-host interaction gene database, ∼16% of Metarhizium genes were identified that are similar to experimentally verified genes involved in pathogenicity in other fungi, particularly plant pathogens. However, relative to M. acridum, M. anisopliae has evolved with many expanded gene families of proteases, chitinases, cytochrome P450s, polyketide synthases, and nonribosomal peptide synthetases for cuticle-degradation, detoxification, and toxin biosynthesis that may facilitate its ability to adapt to heterogenous environments. Transcriptional analysis of both fungi during early infection processes provided further insights into the genes and pathways involved in infectivity and specificity. Of particular note, M. acridum transcribed distinct G-protein coupled receptors on cuticles from locusts (the natural hosts) and cockroaches, whereas M. anisopliae transcribed the same receptor on both hosts. This study will facilitate the identification of virulence genes and the development of improved biocontrol strains with customized properties

    Do the same genes underlie parallel phenotypic divergence in different Littorina saxatilis populations?

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    Parallel patterns of adaptive divergence and speciation are cited as powerful evidence for the role of selection driving these processes. However, it is often not clear whether parallel phenotypic divergence is underlain by parallel genetic changes. Here, we asked about the genetic basis of parallel divergence in the marine snail Littorina saxatilis, which has repeatedly evolved coexisting ecotypes adapted to either crab predation or wave action. We sequenced the transcriptome of snails of both ecotypes from three distant geographical locations (Spain, Sweden and United Kingdom) and mapped the reads to the L. saxatilis reference genome. We identified genomic regions potentially under divergent selection between ecotypes within each country, using an outlier approach based on FST values calculated per locus. In line with previous studies indicating that gene reuse is generally common, we expected to find extensive sharing of outlier loci due to recent shared ancestry and gene flow between at least two of the locations in our study system. Contrary to our expectations, we found that most outliers were country specific, suggesting that much of the genetic basis of divergence is not shared among locations. However, we did find that more outliers were shared than expected by chance and that differentiation of shared outliers is often generated by the same SNPs. We discuss two mechanisms potentially explaining the limited amount of sharing we observed. First, a polygenic basis of divergent traits might allow for multiple distinct molecular mechanisms generating the same phenotypic patterns. Second, additional, location-specific axes of selection that we did not focus on in this study may produce distinct patterns of genetic divergence within each site
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