Tyre particle exposure affects the health of two key estuarine invertebrates.

Tyre wear particles may be the largest source of microplastic to the natural environment, yet information on their biological impacts is inadequate. Two key estuarine invertebrates; the clam Scrobicularia plana and the ragworm Hediste diversicolor were exposed to 10% tyre particles in sediment for three days. Both species consumed the particles, although S. plana consumed 25x more than H. diversicolor (967 compared with 35 particles.g-1 wet weight, respectively). We then investigated the impact of 21 days exposure to different concentrations of tyre particles in estuarine sediments (0.2, 1, and 5% dry weight sediment) on aspects of the health of S. plana and H. diversicolor. Reductions in feeding and burial rates were observed for S. plana but not H. diversicolor, whilst both species showed a decrease in protein content in response to the greatest tyre particle concentration (5%), linked to an 18% decrease in energy reserves for H. diversicolor. Five percent tyre particle exposure led to an increase in total glutathione in the tissues of H. diversicolor, whilst lipid peroxidation decreased in the digestive glands of S. plana, possibly due to an increase in cell turnover. This study found that S. plana's health was impacted at lower concentrations than H. diversicolor, likely due to its consumption of large quantities of sediment. At the high exposure concentration (5%), the health of both invertebrates was impacted. This study did not separate the effects caused by the microplastic particles versus the effects of the chemical additives leaching from these particles, but our results do indicate that future studies should investigate effects in isolation and in combination, to determine the main drivers of toxicity

Separating Stimulus-Induced and Background Components of Dynamic Functional Connectivity in Naturalistic fMRI

We consider the challenges in extracting stimulus-related neural dynamics from other intrinsic processes and noise in naturalistic functional magnetic resonance imaging (fMRI). Most studies rely on inter-subject correlations (ISC) of low-level regional activity and neglect varying responses in individuals. We propose a novel, data-driven approach based on low-rank plus sparse (L+S) decomposition to isolate stimulus-driven dynamic changes in brain functional connectivity (FC) from the background noise, by exploiting shared network structure among subjects receiving the same naturalistic stimuli. The time-resolved multi-subject FC matrices are modeled as a sum of a low-rank component of correlated FC patterns across subjects, and a sparse component of subject-specific, idiosyncratic background activities. To recover the shared low-rank subspace, we introduce a fused version of principal component pursuit (PCP) by adding a fusion-type penalty on the differences between the columns of the low-rank matrix. The method improves the detection of stimulus-induced group-level homogeneity in the FC profile while capturing inter-subject variability. We develop an efficient algorithm via a linearized alternating direction method of multipliers to solve the fused-PCP. Simulations show accurate recovery by the fused-PCP even when a large fraction of FC edges are severely corrupted. When applied to natural fMRI data, our method reveals FC changes that were time-locked to auditory processing during movie watching, with dynamic engagement of sensorimotor systems for speech-in-noise. It also provides a better mapping to auditory content in the movie than ISC

New web-based applications for mechanistic case diagramming

The goal of mechanistic case diagraming (MCD) is to provide students with more in-depth understanding of cause and effect relationships and basic mechanistic pathways in medicine. This will enable them to better explain how observed clinical findings develop from preceding pathogenic and pathophysiological events. The pedagogic function of MCD is in relating risk factors, disease entities and morphology, signs and symptoms, and test and procedure findings in a specific case scenario with etiologic pathogenic and pathophysiological sequences within a flow diagram. In this paper, we describe the addition of automation and predetermined lists to further develop the original concept of MCD as described by Engelberg in 1992 and Guerrero in 2001. We demonstrate that with these modifications, MCD is effective and efficient in small group case-based teaching for second-year medical students (ratings of ~3.4 on a 4.0 scale). There was also a significant correlation with other measures of competency, with a ‘true’ score correlation of 0.54. A traditional calculation of reliability showed promising results (α =0.47) within a low stakes, ungraded environment. Further, we have demonstrated MCD's potential for use in independent learning and TBL. Future studies are needed to evaluate MCD's potential for use in medium stakes assessment or self-paced independent learning and assessment. MCD may be especially relevant in returning students to the application of basic medical science mechanisms in the clinical years

Heterogeneity of impacts of high CO2 on the North Western European Shelf

The increase in atmospheric CO2 is a dual threat to the marine environment: from one side it drives climate change, leading to modifications in water temperature, circulation patterns and stratification intensity; on the other side it causes a decrease in marine pH (ocean acidification, or OA) due to the increase in dissolved CO2. Assessing the combined impact of climate change and OA on marine ecosystems is a challenging task. The response of the ecosystem to a single driver can be highly variable and remains still uncertain; additionally the interaction between these can be either synergistic or antagonistic. In this work we use the coupled oceanographic–ecosystem model POLCOMS-ERSEM driven by climate forcing to study the interaction between climate change and OA. We focus in particular on carbonate chemistry, primary and secondary production. The model has been run in three different configurations in order to assess separately the impacts of climate change on net primary production and of OA on the carbonate chemistry, which have been strongly supported by scientific literature, from the impact of biological feedbacks of OA on the ecosystem, whose uncertainty still has to be well constrained. The global mean of the projected decrease of pH at the end of the century is about 0.27 pH units, but the model shows significant interaction among the drivers and high variability in the temporal and spatial response. As a result of this high variability, critical tipping point can be locally and/or temporally reached: e.g. undersaturation with respect to aragonite is projected to occur in the deeper part of the central North Sea during summer. Impacts of climate change and of OA on primary and secondary production may have similar magnitude, compensating in some area and exacerbating in others

Integrated human papillomavirus analysis as an adjunct for triage of atypical cervical cytology

published_or_final_versio

Costs associated with febrile neutropenia in solid tumor and lymphoma patients - an observational study in Singapore.

BackgroundThe primary objective was to describe the total direct inpatient costs among solid tumor and lymphoma patients with chemotherapy-induced febrile neutropenia (FN) and the factors that were associated with higher direct cost. The secondary objective was to describe the out-of-pocket patient payments and the factors that were associated with higher out-of-pocket patient payments.MethodsThis was a single-center observational study conducted at the largest cancer center in Singapore. All of the adult cancer patients hospitalized due to FN from 2009 to 2012 were studied. The primary outcomes were the total hospital cost and the out-of-pocket patient payments (adjusted by government subsidy) per FN episode. Univariate analysis and multiple linear regression were conducted to identify the factors associated with higher FN costs.ResultsThree hundred and sixty seven adult cancer patients were documented with FN-related hospitalizations. The mean total hospital cost was US$4,193 (95$3,779-4,607) and the mean out-of-pocket patient payment was US$2,230 (95$1,976-2,484), per FN episode. The factors associated with a higher total hospital cost were longer length of stay, severe sepsis, and lymphoma as underlying cancer. The out-of-pocket patient payment was positively associated with longer length of stay, severe sepsis, lymphoma diagnosed as underlying cancer, the therapeutic use of granulocyte colony-stimulating factor (GCSF), the private ward class, and younger patients.ConclusionsThe total hospital cost and out-of-pocket patient payments of FN management in lymphoma cases were substantial compared with other solid tumors. Factors associated with a higher FN management cost may be useful for developing appropriate strategies to reduce the cost of FN for cancer patients

Modelling the combined impacts of climate change and direct anthropogenic drivers on the ecosystem of the northwest European continental shelf

The potential response of the marine ecosystem of the northwest European continental shelf to climate change under a medium emissions scenario (SRES A1B) is investigated using the coupled hydrodynamics-ecosystem model POLCOMS-ERSEM. Changes in the near future (2030–2040) and the far future (2082–2099) are compared to the recent past (1983–2000). The sensitivity of the ecosystem to potential changes in multiple anthropogenic drivers (river nutrient loads and benthic trawling) in the near future is compared to the impact of changes in climate. With the exception of the biomass of benthic organisms, the influence of the anthropogenic drivers only exceeds the impact of climate change in coastal regions. Increasing river nitrogen loads has a limited impact on the ecosystem whilst reducing river nitrogen and phosphate concentrations affects net primary production(netPP) and phytoplankton and zooplankton biomass. Direct anthropogenic forcing is seen to mitigate/amplify the effects of climate change. Increasing river nitrogen has the potential to amplify the effects of climate change at the coast by increasing netPP. Reducing river nitrogen and phosphate mitigates the effects of climate change for netPP and the biomass of small phytoplankton and large zooplankton species but amplifies changes in the biomass of large phytoplankton and small zooplankton

Intermittent preventive treatment with dihydroartemisinin-piperaquine in Ugandan schoolchildren selects for Plasmodium falciparum transporter polymorphisms that modify drug sensitivity.

Dihydroartemisinin-piperaquine (DP) offers prolonged protection against malaria, but its impact on Plasmodium falciparum drug sensitivity is uncertain. In a trial of intermittent preventive treatment in schoolchildren in Tororo, Uganda, in 2011 to 2012, monthly DP for 1 year decreased the incidence of malaria by 96% compared to placebo; DP once per school term offered protection primarily during the first month after therapy. To assess the impact of DP on selection of drug resistance, we compared the prevalence of key polymorphisms in isolates that emerged at different intervals after treatment with DP. Blood obtained monthly and at each episode of fever was assessed for P. falciparum parasitemia by microscopy. Samples from 160 symptomatic and 650 asymptomatic episodes of parasitemia were assessed at 4 loci (N86Y, Y184F, and D1246Y in pfmdr1 and K76T in pfcrt) that modulate sensitivity to aminoquinoline antimalarials, utilizing a ligase detection reaction-fluorescent microsphere assay. For pfmdr1 N86Y and pfcrt K76T, but not the other studied polymorphisms, the prevalences of mutant genotypes were significantly greater in children who had received DP within the past 30 days than in those not treated within 60 days (86Y, 18.0% versus 8.3% [P = 0.03]; 76T, 96.0% versus 86.1% [P = 0.05]), suggesting selective pressure of DP. Full sequencing of pfcrt in a subset of samples did not identify additional polymorphisms selected by DP. In summary, parasites that emerged soon after treatment with DP were more likely than parasites not under drug pressure to harbor pfmdr1 and pfcrt polymorphisms associated with decreased sensitivity to aminoquinoline antimalarials. (This study has been registered at ClinicalTrials.gov under no. NCT01231880.)

Revision of the Late Jurassic teleosaurid genus Machimosaurus (Crocodylomorpha, Thalattosuchia)

© 2014 The Authors. Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use, provided the original author and source are credited. The attached file is the published version of the article

Development of a vehicle track interaction model to predict the vibratory benefits of rail grinding in the time domain

Imperfections in the wheel-rail contact are one of the main sources of generation of railway vibrations. Consequently, it is essential to take expensive corrective maintenance measures, the results of which may be unknown. In order to assess the effectiveness of these measures, this paper develops a vehicle-track interaction model in the time domain of a curved track with presence of rail corrugation on the inner rail. To characterize the behavior of the track, a numerical finite element model is developed using ANSYS software, while the behavior of the vehicle is characterized by a unidirectional model of two masses developed with VAMPIRE PRO software. The overloads obtained with the dynamic model are applied to the numerical model and then, the vibrational response of the track is obtained. Results are validated with real data and used to assess the effectiveness of rail grinding in the reduction of wheel-rail forces and the vibration generation phenomenon.Real Herráiz, JI.; Zamorano, C.; Velarte, JL.; Blanco, AE. (2015). Development of a vehicle track interaction model to predict the vibratory benefits of rail grinding in the time domain. Journal of Modern Transportation. 23(3):189-201. doi:10.1007/s40534-015-0078-yS189201233Grassie SL, Kalousek J (1993) Rail corrugation: characteristics, causes and treatments. Proc Inst Mech Eng Part F: J Rail Rapid Transit 207:57–68Grassie SL (2005) Rail corrugation: advances in measurement, understanding and treatment. Wear 258:1224–1234Grassie SL (2009) Rail corrugation: characteristics, causes and treatments. Proc Inst Mech Eng Part F: J Rail Rapid Transit 223:581–596Suda Y, Komine H, Iwasa T, Terumichi Y (2002) Experimental study on mechanism of rail corrugation using corrugation simulator. Wear 253:162–171Jin XS, Wen ZF, Wang KY, Zhou ZR, Liu QY, Li CH (2006) Three-dimensional train–track model for study of rail corrugation. J Sound Vib 293(3):830–855Zhao X, Li Z, Esveld C, Dollevoet R (2007) The dynamic stress state of the wheel–rail contact. In: Proceedings of the 2nd IASME/WSEAS international conference on continuum mechanicsTorstensson P, Nielsen J (2011) Simulation of dynamic vehicle-track interaction on small radius curves. Veh Syst Dyn 49(11):1711–1732Hawari HM, Murray MH (2008) Effects of train characteristics on the rate of deterioration of track roughness. J Eng Mech 134(3):234–239Ling L, Li W, Shang H, Xiao X, Wen Z, Jin X (2014) Experimental and numerical investigation of the effect of rail corrugation on the behaviour of rail fastenings. Veh Syst Dyn 52(9):1211–1231Collette C, Horodinca M, Preumont A (2009) Rotational vibration absorber for the mitigation of rail rutting corrugation. Veh Syst Dyn 47:641–659Egaña J, Viñolas J, Gil-Negrete L (2005) Effect of liquid high positive friction (HPF) modifier on wheel-rail contact and rail corrugation. Tribol Int 38:769–774Real Herraiz JI, Galisteo Cabeza A, Real T, Zamorano Martin C (2012) Study of wave barriers design for the mitigation of railway ground vibrations. J Vibroeng 14(1):408–422Real JI, Zamorano C, Hernandez C, Comendador R, Real T (2014) Computational considerations of 3-D finite element method models of railway vibration prediction in ballasted tracks. J Vibroeng 16(4):1709–1722Andersen L, Jones CJ (2001) Three-dimensional elastodynamic analysis using multiple boundary element domains. ISVR Technical Memorandum, University of Southampton, SouthamptonLópez Pita A (2006) Infraestructuras Ferroviarias. Universitat Politècnica de Catalunya, BarcelonaAlves P, Calçada R, Silva A (2011) Vibrations induced by railway traffic: influence of the mechanical properties of the train on the dynamic excitation mechanism. In: Proceedings of the 8th international conference on structural dynamics, EURODYN 2011, Leuven, BelgiumFerrara R, Leonardi G, Jourdan F (2012) Numerical modelling of train induced vibrations. In: SIIV-5th international congress—sustainability of road infrastructures, Rome, ItalyUzzal RU, Ahmed AK, Bhat RB (2013) Modelling, validation and analysis of a three-dimensional railway vehicle–track system model with linear and nonlinear track properties in the presence of wheel flats. Veh Syst Dyn 51(11):1695–1721Eadie DT, Kalousek J, Chiddick KC (2002) The role of high positive friction (HPF) modifier in the control of short pitch corrugations and related phenomena. Wear 253:185–19