644 research outputs found

    Undulation Instability of Epithelial Tissues

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    Treating the epithelium as an incompressible fluid adjacent to a viscoelastic stroma, we find a novel hydrodynamic instability that leads to the formation of protrusions of the epithelium into the stroma. This instability is a candidate for epithelial fingering observed in vivo. It occurs for sufficiently large viscosity, cell-division rate and thickness of the dividing region in the epithelium. Our work provides physical insight into a potential mechanism by which interfaces between epithelia and stromas undulate, and potentially by which tissue dysplasia leads to cancerous invasion.Comment: 4 pages, 3 figure

    Teratogenic risk and contraceptive counselling in psychiatric practice: analysis of anticonvulsant therapy

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    <p>Background: Anticonvulsants have been used to manage psychiatric conditions for over 50 years. It is recognised that some, particularly valproate, carbamazepine and lamotrigine, are human teratogens, while others including topiramate require further investigation. We aimed to appraise the documentation of this risk by psychiatrists and review discussion around contraceptive issues.</p> <p>Methods: A retrospective review of prescribing patterns of four anticonvulsants (valproate, carbamazepine, lamotrigine and topiramate) in women of child bearing age was undertaken. Documented evidence of discussion surrounding teratogenicity and contraceptive issues was sought.</p> <p>Results: Valproate was most commonly prescribed (n=67). Evidence of teratogenic risk counselling at medication initiation was sub-optimal ‚Äď 40% of individuals prescribed carbamazepine and 22% of valproate. Documentation surrounding contraceptive issues was also low- 17% of individuals prescribed carbamazepine and 13% of valproate.</p> <p>Conclusion: We found both low rates of teratogenic risk counselling and low rates of contraception advice in our cohort. Given the high rates of unplanned pregnancies combined with the relatively high risk of major congenital malformations, it is essential that a detailed appraisal of the risks and benefits associated with anticonvulsant medication occurs and is documented within patients‚Äô psychiatric notes.</p&gt

    Socio-economic impact of Foot-and-Mouth Disease outbreaks and control measures:An analysis of Mongolian outbreaks in 2017

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    Mongolia is a large landlocked country in central Asia and has one of the highest per capita livestock ratios in the world. During 2017 reported Foot and Mouth disease (FMD) outbreaks in Mongolia increased considerably, prompting widespread disease control measures. This study estimates the socio‚Äźeconomic impact of FMD and subsequent control measures on Mongolian herders. The analysis encompassed quantification of the impact on subsistence farmers‚Äô livelihoods and food security and estimation of the national level gross losses due to reaction and expenditure during 2017. Data were collected from 112 herders across eight Provinces that reported disease. Seventy of these herders had cases of FMD, while 42 did not have FMD in their animals but were within quarantine zones. Overall, 86/112 herders reported not drinking milk for a period of time and 38/112 reduced their meat consumption. Furthermore, 55 herders (49.1%) had to borrow money to buy food, medicines and/or pay bills or bank loans. Among herders with FMD cases, the median attack rate was 31.7%, 3.8% and 0.59% in cattle, sheep and goats respectively, with important differences across Provinces. Herders with clinical cases before the winter had higher odds of reporting a reduction in their meat consumption. National level gross losses due to FMD in 2017 were estimated using government data. The estimate of gross economic loss was 18.4 billion Mongolian‚Äźtugriks (US$7.35 million) which equates to approximately 0.65% of the Mongolian GDP. The FMD outbreaks combined with current control measures has negatively impacted herders‚Äô livelihoods (including herders with and without cases of FMD) which is likely to reduce stakeholder advocacy. Possible strategies that could be employed to ameliorate the negative effects of the current control policy were identified. The findings and approach are relevant to other FMD endemic regions aiming to control the disease

    Mathematical and Statistical Techniques for Systems Medicine: The Wnt Signaling Pathway as a Case Study

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    The last decade has seen an explosion in models that describe phenomena in systems medicine. Such models are especially useful for studying signaling pathways, such as the Wnt pathway. In this chapter we use the Wnt pathway to showcase current mathematical and statistical techniques that enable modelers to gain insight into (models of) gene regulation, and generate testable predictions. We introduce a range of modeling frameworks, but focus on ordinary differential equation (ODE) models since they remain the most widely used approach in systems biology and medicine and continue to offer great potential. We present methods for the analysis of a single model, comprising applications of standard dynamical systems approaches such as nondimensionalization, steady state, asymptotic and sensitivity analysis, and more recent statistical and algebraic approaches to compare models with data. We present parameter estimation and model comparison techniques, focusing on Bayesian analysis and coplanarity via algebraic geometry. Our intention is that this (non exhaustive) review may serve as a useful starting point for the analysis of models in systems medicine.Comment: Submitted to 'Systems Medicine' as a book chapte

    Recarga artificial en Bajos Submeridionales

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    Se presenta la experiencia en desarrollo en un sector de Bajos Submeridionales pr√≥ximo a Tostado, para monitorear los efectos de la recarga artificial de acu√≠feros. El objetivo del estudio es mejorar la disponibilidad de agua en calidad y cantidad para uso ganadero y evaluar una obra de recarga a partir de un pozo doble prop√≥sito recarga ‚Äď bombeo para mejorar su eficiencia, y difundir estas pr√°cticas.El √°rea piloto se ubica en un paleocauce arenoso del r√≠o Salado. En el mismo se han realizado numerosos estudios geoel√©ctricos, de infiltraci√≥n, sedimentol√≥gicos, qu√≠micos recuperaci√≥n de niveles, de suelos y de recarga. Adem√°s se dispone de una estaci√≥n meteorol√≥gica autom√°tica, caudal√≠metro y freat√≠metros. Se realiz√≥ un an√°lisis de eventos de recarga y su efecto sobre el sistema natural y en la obra. Se concluye que ha resultado exitosa y puede ser transferida a otros ambientes de paleocauces del chaco-santafesino.This work describes an artificial recharge experience of groundwater as source for animal beverage, de veloped on a livestock demonstrative unit, placed in Bajos Submeridionales, Santa Fe province, Argentina. The aim of this study is to improve quality and quantity of water for livestock use, analyze a recharge-pumping well efficiency, and finally to spread this practice in the region. The study area is located in a antique sandy channel of the Salado river, where have been conducted geoelectric studies, sedimentologic, soil and water analysis, pumping and recharge, and infiltration tests. Additionally, it counts with metheorological on-line data from an automatic station, flowmeter, and water-level measurements from digital and analogical devises. An analysis of a recharge event has been conducted in order to assess environmental changes and response of facilities. This successful experience suggests that these kinds of facilities could be applied in similar environments of chaco-santafesino region.Universidad Nacional de La Plat

    Combination of the W boson polarization measurements in top quark decays using ATLAS and CMS data at root s=8 TeV

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    The combination of measurements of the W boson polarization in top quark decays performed by the ATLAS and CMS collaborations is presented. The measurements are based on proton-proton collision data produced at the LHC at a centre-of-mass energy of 8 TeV, and corresponding to an integrated luminosity of about 20 fb(-1)for each experiment. The measurements used events containing one lepton and having different jet multiplicities in the final state. The results are quoted as fractions of W bosons with longitudinal (F-0), left-handed (F-L), or right-handed (F-R) polarizations. The resulting combined measurements of the polarization fractions are F-0= 0.693 +/- 0.014 and F-L= 0.315 +/- 0.011. The fractionF(R)is calculated from the unitarity constraint to be F-R=-0.008 +/- 0.007. These results are in agreement with the standard model predictions at next-to-next-to-leading order in perturbative quantum chromodynamics and represent an improvement in precision of 25 (29)% for F-0(F-L) with respect to the most precise single measurement. A limit on anomalous right-handed vector (V-R), and left- and right-handed tensor (g(L), g(R)) tWb couplings is set while fixing all others to their standard model values. The allowed regions are [-0.11,0.16] for V-R, [-0.08,0.05] for g(L), and [-0.04,0.02] for g(R), at 95% confidence level. Limits on the corresponding Wilson coefficients are also derived.Peer reviewe

    A search for the dimuon decay of the Standard Model Higgs boson with the ATLAS detector