182 research outputs found

    Predicting Geotechnical Parameters from Seismic Wave Velocity Using Artificial Neural Networks

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    Geotechnical investigation plays an indispensable role in site characterization and provides necessary data for various construction projects. However, geotechnical measurements are time-consuming, point-based, and invasive. Non-destructive geophysical measurements (seismic wave velocity) can complement geotechnical measurements to save project money and time. However, correlations between geotechnical and seismic wave velocity are crucial in order to maximize the benefit of geophysical information. In this work, artificial neural networks (ANNs) models are developed to forecast geotechnical parameters from seismic wave velocity. Specifically, published seismic wave velocity, liquid limit, plastic limit, water content, and dry density from field and laboratory measurements are used to develop ANN models. Due to the small number of data, models are developed with and without the validation step in order to use more data for training. The results indicate that the performance of the models is improved by using more data for training. For example, predicting seismic wave velocity using more data for training improves the R2 value from 0.50 to 0.78 and reduces the ASE from 0.0174 to 0.0075, and MARE from 30.75 to 18.53. The benefit of adding velocity as an input parameter for predicting water content and dry density is assessed by comparing models with and without velocity. Models incorporating the velocity information show better predictability in most cases. For example, predicting water content using field data including the velocity improves the R2 from 0.75 to 0.85 and reduces the ASE from 0.0087 to 0.0051, and MARE from 10.68 to 7.78. A comparison indicates that ANN models outperformed multilinear regression models. For example, predicting seismic wave velocity using field plus lab data has an ANN derived R2 value that is 81.39% higher than regression model

    Acoustic end corrections for micro-perforated plates

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    © 2019 Acoustical Society of America. Micro-perforated plates (MPPs) are acoustically important elements in micro-electro-mechanical systems (MEMS). In this work an analytical solution for perforated plates is combined with finite element method (FEM) to develop formulas for the reactive and resistive end effects of the perforations on the plate. The reactive end effect is found to depend on the hole radius and porosity. The resistive end effect is found to depend on hole radius only. FEM is also used to develop an understanding of the loss mechanism that corresponds to the resistive end effects. The developed models can be used in optimization studies of the MEMS and MPPs

    Decreased hydrogen peroxide production and mitochondrial respiration in skeletal muscle but not cardiac muscle of the green-striped burrowing frog, a natural model of muscle disuse

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    Suppression of disuse-induced muscle atrophy has been associated with altered mitochondrial reactive oxygen species (ROS) production in mammals. However, despite extended hindlimb immobility, aestivating animals exhibit little skeletal muscle atrophy compared with artificially immobilised mammalian models. Therefore, we studied mitochondrial respiration and ROS (H2O2) production in permeabilised muscle fibres of the green-striped burrowing frog, Cyclorana alboguttata. Mitochondrial respiration within saponin-permeabilised skeletal and cardiac muscle fibres was measured concurrently with ROS production using high-resolution respirometry coupled to custom-made fluorometers. After 4 months of aestivation, C. alboguttata had significantly depressed whole-body metabolism by similar to 70% relative to control (active) frogs, and mitochondrial respiration in saponin-permeabilised skeletal muscle fibres decreased by almost 50% both in the absence of ADP and during oxidative phosphorylation. Mitochondrial ROS production showed up to an 88% depression in aestivating skeletal muscle when malate, succinate and pyruvate were present at concentrations likely to reflect those in vivo. The percentage ROS released per O-2 molecule consumed was also similar to 94% less at these concentrations, indicating an intrinsic difference in ROS production capacities during aestivation. We also examined mitochondrial respiration and ROS production in permeabilised cardiac muscle fibres and found that aestivating frogs maintained respiratory flux and ROS production at control levels. These results show that aestivating C. alboguttata has the capacity to independently regulate mitochondrial function in skeletal and cardiac muscles. Furthermore, this work indicates that ROS production can be suppressed in the disused skeletal muscle of aestivating frogs, which may in turn protect against potential oxidative damage and preserve skeletal muscle structure during aestivation and following arousal

    Characterization and performance of nucleic acid nanoparticles combined with protamine and gold

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    Macromolecular nucleic acids such as DNA vaccines, siRNA, and splice-site switching oligomers (SSO) have vast chemotherapeutic potential. Nanoparticulate biomaterials hold promise for DNA and RNA delivery when a means for binding is identified that retains structure-function and provides stabilization by the nanoparticles. In order to provide these benefits of binding, we combined DNA and RNA with protamine— demonstrating association to gold microparticles by electrophoretic, gel shot, fluorescence, and dynamic laser light spectroscopy (DLLS). A pivotal finding in these studies is that the Au-protamine-DNA conjugates greatly stabilize the DNA; and DNA structure and vaccine activity are maintained even after exposure to physical, chemical, and temperature-accelerated degradation. Specifically, protamine formed nanoparticles when complexed to RNA. These complexes could be detected by gel shift and were probed by high throughput absorbance difference spectroscopy (HTADS). Biological activity of these RNA nanoparticles (RNPs) was demonstrated also by a human tumor cell splice-site switching assay and by siRNA delivery against B-Raf—a key cancer target. Finally, RNA:protamine particles inhibited growth of cultured human tumor cells and bacteria. These data provide new insights into DNA and RNA nanoparticles and prospects for their delivery and chemotherapeutic activity

    Power and the durability of poverty: a critical exploration of the links between culture, marginality and chronic poverty

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    Neurological and behavioral abnormalities, ventricular dilatation, altered cellular functions, inflammation, and neuronal injury in brains of mice due to common, persistent, parasitic infection.

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    BACKGROUND: Worldwide, approximately two billion people are chronically infected with Toxoplasma gondii with largely unknown consequences. METHODS: To better understand long-term effects and pathogenesis of this common, persistent brain infection, mice were infected at a time in human years equivalent to early to mid adulthood and studied 5-12 months later. Appearance, behavior, neurologic function and brain MRIs were studied. Additional analyses of pathogenesis included: correlation of brain weight and neurologic findings; histopathology focusing on brain regions; full genome microarrays; immunohistochemistry characterizing inflammatory cells; determination of presence of tachyzoites and bradyzoites; electron microscopy; and study of markers of inflammation in serum. Histopathology in genetically resistant mice and cytokine and NRAMP knockout mice, effects of inoculation of isolated parasites, and treatment with sulfadiazine or alphaPD1 ligand were studied. RESULTS: Twelve months after infection, a time equivalent to middle to early elderly ages, mice had behavioral and neurological deficits, and brain MRIs showed mild to moderate ventricular dilatation. Lower brain weight correlated with greater magnitude of neurologic abnormalities and inflammation. Full genome microarrays of brains reflected inflammation causing neuronal damage (Gfap), effects on host cell protein processing (ubiquitin ligase), synapse remodeling (Complement 1q), and also increased expression of PD-1L (a ligand that allows persistent LCMV brain infection) and CD 36 (a fatty acid translocase and oxidized LDL receptor that mediates innate immune response to beta amyloid which is associated with pro-inflammation in Alzheimer's disease). Immunostaining detected no inflammation around intra-neuronal cysts, practically no free tachyzoites, and only rare bradyzoites. Nonetheless, there were perivascular, leptomeningeal inflammatory cells, particularly contiguous to the aqueduct of Sylvius and hippocampus, CD4+ and CD8+ T cells, and activated microglia in perivascular areas and brain parenchyma. Genetically resistant, chronically infected mice had substantially less inflammation. CONCLUSION: In outbred mice, chronic, adult acquired T. gondii infection causes neurologic and behavioral abnormalities secondary to inflammation and loss of brain parenchyma. Perivascular inflammation is prominent particularly contiguous to the aqueduct of Sylvius and hippocampus. Even resistant mice have perivascular inflammation. This mouse model of chronic T. gondii infection raises questions of whether persistence of this parasite in brain can cause inflammation or neurodegeneration in genetically susceptible hosts

    Self-compassion and risk behavior among people living with HIV/AIDS.

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    Sexual risk behavior and illicit drug use among people living with HIV/AIDS (PLWHA) contribute to poor health and onward transmission of HIV. The aim of this collaborative multi-site nursing research study was to explore the association between self-compassion and risk behaviors in PLWHA. As part of a larger project, nurse researchers in Canada, China, Namibia, Puerto Rico, Thailand and the US enrolled 1211 sexually active PLWHA using convenience sampling. The majority of the sample was male, middle-aged, and from the US. Illicit drug use was strongly associated with sexual risk behavior, but participants with higher self-compassion were less likely to report sexual risk behavior, even in the presence of illicit drug use. Self-compassion may be a novel area for behavioral intervention development for PLWHA

    Transnasal Humidified Rapid Insufflation Ventilatory Exchange in children requiring emergent intubation (Kids THRIVE): a statistical analysis plan for a randomised controlled trial

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    Published online: 31 May 2023The placement of an endotracheal tube for children with acute or critical illness is a low-frequency and high-risk procedure, associated with high rates of first-attempt failure and adverse events, including hypoxaemia. To reduce the frequency of these adverse events, the provision of oxygen to the patient during the apnoeic phase of intubation has been proposed as a method to prolong the time available for the operator to insert the endotracheal tube, prior to the onset of hypoxaemia. However, there are limited data from randomised controlled trials to validate the efficacy of this technique in children. The technique known as transnasal humidified rapid insufflation ventilatory exchange (THRIVE) uses high oxygen flow rates (approximately 2 L/kg/min) delivered through nasal cannulae during apnoea. It has been shown to at least double the amount of time available for safe intubation in healthy children undergoing elective surgery. The technique and its application in real time have not previously been studied in acutely ill or injured children presenting to the emergency department or admitted to an intensive care unit. The Kids THRIVE trial is a multicentre, international, randomised controlled trial (RCT) in children less than 16 years old undergoing emergent intubation in either the intensive care unit or emergency department of participating hospitals. Participants will be randomised to receive either the THRIVE intervention or standard care (no apnoeic oxygenation) during their intubation. The primary objective of the trial is to determine if the use of THRIVE reduces the frequency of oxygen desaturation and increases the frequency of first-attempt success without hypoxaemia in emergent intubation of children compared with standard practice. The secondary objectives of the study are to assess the impact of the use of THRIVE on the rate of adverse events, length of mechanical ventilation and length of stay in intensive care. In this paper, we describe the detailed statistical analysis plan as an update of the previously published protocol.Shane George, Kristen Gibbons, Tara Williams, Susan Humphreys, Ben Gelbart, Renate Le Marsney, Simon Craig, David Tingay, Arjun Chavan, Andreas Schibler, for the Kids THRIVE Investigators, Paediatric Research in Emergency Departments International Collaborative (PREDICT) and the Australia, New Zealand Intensive Care Society Paediatric Study Group (ANZICS PSG). Kids THRIVE Investigators: Shane George ... Subodh Ganu et al

    Alternative patterns of sex chromosome differentiation in Aedes aegypti (L).

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    BACKGROUND: Some populations of West African Aedes aegypti, the dengue and zika vector, are reproductively incompatible; our earlier study showed that divergence and rearrangements of genes on chromosome 1, which bears the sex locus (M), may be involved. We also previously described a proposed cryptic subspecies SenAae (PK10, Senegal) that had many more high inter-sex FST genes on chromosome 1 than did Ae.aegypti aegypti (Aaa, Pai Lom, Thailand). The current work more thoroughly explores the significance of those findings. RESULTS: Intersex standardized variance (FST) of single nucleotide polymorphisms (SNPs) was characterized from genomic exome capture libraries of both sexes in representative natural populations of Aaa and SenAae. Our goal was to identify SNPs that varied in frequency between males and females, and most were expected to occur on chromosome 1. Use of the assembled AaegL4 reference alleviated the previous problem of unmapped genes. Because the M locus gene nix was not captured and not present in AaegL4, the male-determining locus, per se, was not explored. Sex-associated genes were those with FST values ≥ 0.100 and/or with increased expected heterozygosity (H exp , one-sided T-test, p < 0.05) in males. There were 85 genes common to both collections with high inter-sex FST values; all genes but one were located on chromosome 1. Aaa showed the expected cluster of high inter-sex FST genes proximal to the M locus, whereas SenAae had inter-sex FST genes along the length of chromosome 1. In addition, the Aaa M-locus proximal region showed increased H exp levels in males, whereas SenAae did not. In SenAae, chromosomal rearrangements and subsequent suppressed recombination may have accelerated X-Y differentiation. CONCLUSIONS: The evidence presented here is consistent with differential evolution of proto-Y chromosomes in Aaa and SenAae
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