An overview of recent applications of computational modelling in neonatology

This article has been made available through the Brunel Open Access Publishing Fund.This paper reviews some of our recent applications of Computational Fluid Dynamics (CFD) to model heat and mass transfer problems in neonatology and investigates the major heat and mass transfer mechanisms taking place in medical devices such as incubators, radiant warmers and oxygen hoods. It is shown that CFD simulations are very flexible tools that can take into account all modes of heat transfer in assisting neonatal care and improving the design of medical devices.Brunel Open Access Publishing Fun

Characterization of Chlorella sorokiniana, UTEX 1230

This paper characterizes the strain Chlorella sorokiniana UTEX 1230 within a laboratory setting using a 1 L bubble column. The findings show that productivity can be trebled under mixotrophic conditions (from 0.2 g·L−1·d−1 to 0.66 g·L−1·d−1) with the addition of sodium acetate. The results also indicate that both the growth rate and final yield increase with the cultivation temperature, with most parameters showing an optimum in the range of 30–35 °C. The maximum specific growth rate was found to be in the region of 0.12 h−1 at a surface irradiance between 100–500 µE·m−2·s−1. This high growth rate makes the strain particularly suited to the rapid production of biomass, suitable for either whole cell bioprocessing or bioremediation. However, the relatively low lipid productivity (9.2 mg·L−1·d−1) confirms previous findings which would indicate poor applicability for biodiesel production. The strain shows greater promise in wastewater treatment applications with removal rates of nitrogen and phosphorus in the region of 37 and 30 mg·L−1·d−1 respectively. Furthermore, the findings show that a fed-batch strategy to inorganic nutrient loading can increase the final yield by around 50% compared to a conventional batch run. This is particularly interesting as fed-batch production techniques are rarely used within microalgal cultivation, so provide an interesting avenue for further investigation. Overall, the findings show that C. sorokiniana UTEX 1230 is a robust and fast-growing microalgal strain suitable both for the laboratory and scale-up

Surface ozone in the Colorado northern Front Range and the influence of oil and gas development during FRAPPE/DISCOVER-AQ in summer 2014

High mixing ratios of ozone (O3) in the northern Front Range (NFR) of Colorado are not limited to the urban Denver area but were also observed in rural areas where oil and gas activity is the primary source of O3 precursors. On individual days, oil and gas O3 precursors can contribute in excess of 30 ppb to O3 growth and can lead to exceedances of the EPA O3 National Ambient Air Quality Standard. Data used in this study were gathered from continuous surface O3 monitors for June–August 2013–2015 as well as additional flask measurements and mobile laboratories that were part of the FRAPPE/DISCOVER-AQ field campaign of July–August 2014. Overall observed O3 levels during the summer of 2014 were lower than in 2013, likely due to cooler and damper weather than an average summer. This study determined the median hourly surface O3 mixing ratio in the NFR on summer days with limited photochemical production to be approximately 45–55 ppb. Mobile laboratory and flask data collected on three days provide representative case studies of different O3 formation environments in and around Greeley, Colorado. Observations of several gases (including methane, ethane, CO, nitrous oxide) along with O3 are used to identify sources of O3 precursor emissions. A July 23 survey demonstrated low O3 (45–60 ppb) while August 3 and August 13 surveys recorded O3 levels of 75–80 ppb or more. August 3 exemplifies influence of moderate urban and high oil and gas O3 precursor emissions. August 13 demonstrates high oil and gas emissions, low agricultural emissions, and CO measurements that were well correlated with ethane from oil and gas, suggesting an oil and gas related activity as a NOx and O3 precursor source. Low isoprene levels indicated that they were not a significant contributor to O3 precursors measured during the case studies

1,5-asymmetric induction in the boron-mediated aldol reactions of beta-oxygenated methyl ketones

High levels of substrate-based 1,5-stereoinduction are obtained in the boron-mediated aldol reactions of P-oxygenated methyl ketones with achiral and chiral aldehydes. Remote induction from the boron enolates gives the 1,5-anti adducts, with the enolate pi-facial selectivity critically dependent upon the nature of the beta-alkoxy protecting group. This 1,5-anti aldol methodology has been strategically employed in the total synthesis of several natural products. At present, the origin of the high level of 1,5-anti induction obtained with the boron enolates is unclear, although a model based on a hydrogen bonding between the alkoxy oxygen and the formyl hydrogen has been recently proposed.3082007201

The Parameterized Complexity of Centrality Improvement in Networks

The centrality of a vertex v in a network intuitively captures how important v is for communication in the network. The task of improving the centrality of a vertex has many applications, as a higher centrality often implies a larger impact on the network or less transportation or administration cost. In this work we study the parameterized complexity of the NP-complete problems Closeness Improvement and Betweenness Improvement in which we ask to improve a given vertex' closeness or betweenness centrality by a given amount through adding a given number of edges to the network. Herein, the closeness of a vertex v sums the multiplicative inverses of distances of other vertices to v and the betweenness sums for each pair of vertices the fraction of shortest paths going through v. Unfortunately, for the natural parameter "number of edges to add" we obtain hardness results, even in rather restricted cases. On the positive side, we also give an island of tractability for the parameter measuring the vertex deletion distance to cluster graphs

Regional specialization of Sarcodes sanguinea (Ericaceae) on a single fungal symbiont from the Rhizopogon ellenae (Rhizopogonaceae) species complex.

Published versio

Integration of hydro-climatic data and land use in neural networks for modeling river flows: Case of Lobo river in the southwest of Cote d’ivoire

In a context of climate disruption due to uncontrolled human activities, the classical models of rainfall - runoff modeling are almost unusable. In addition on the Lobo River (Southwest of Côte d’Ivoire), no simulation study has been carried out yet despite that, this river has flooded fields and villages causing huge losses in September 2007. Neural networks appear in this case as a solution for simulating flows in the context of non-linearity between rainfall and flow of this river. Climatic data (rainfall, temperature and PET) and land use will be phased in neural models to simulate monthly flows of the river Lobo. Four (4) neuronal model variants were constructed from three (3) hydro-climatic parameters (rainfall, potential evapotranspiration and flow) and the land acquired from Landsat ETM + 1990 and ETM + 2000. Two types of models have been created: the unguided model and the guided model. The simulation with the unguided model did not provide a satisfactory result. In effect, the value of Nash is only 22.90%. However, the NASH value of the guided model is much better than the previous one (85.01, 83.38 and 84.05%). These results help to highlight the importance of land use on the performance of neural networks. This study also demonstrated the ability of artificial neural networks to simulate the nongauged river flows in the context of climate disruption.Key words: Côte d’Ivoire, Lobo, multilayer perception, remote sensing, simulation, hydrology, model, neuron, flow

Application des réseaux de neurones formels pour la prévision des débits mensuels du Bandama blanc à la station de Tortiya (Nord de la Côte d’Ivoire)

Plusieurs travaux témoignent de la capacité des réseaux de neurones à modéliser les débits des rivières. Malheureusement on ignore actuellement si ces modèles neuronaux sont performants pour la prévision du binôme pluie-débit en régime tropical humide en général et particulièrement sur le Bandama Blanc dans le Nord de la Côte d‟Ivoire. Ce travail de recherche permettra de vérifier l‟efficacité des réseaux de neurones formels pour la prévision des débits mensuels du Bandama Blanc à partir de la relation pluie-débit qui est non-linéaire. Trois modèles de réseaux de neurones ont donc été optimisés afin d‟atteindre cet objectif. Une base de données composée du débit, de la pluie, de la température et de  l‟Evapotranspiration Potentiel (ETP) au pas de temps mensuel à été utilisée comme entrée de ces modèles.Ces données ont été normalisées entre 0 et 1 et subdivisées en deux blocs : un premier bloc composé des 2/3 des données (1971-1988) pour l‟apprentissage et un second bloc composé du 1/3 des données (1989- 1997) pour la validation. Ces modèles ont été optimisés avec l‟apprentissage supervisé. Le critère de Nash-Sutcliffe et le coefficient de corrélation (R) ont été utilisés pour tester la performance de ces modèles. Les résultats obtenus montrent que tous les modèles expriment plus de 70% de la variation des débits du Bandama Blanc à Tortiya. Pour tous ces modèles, les valeurs du critère de Nash-Sutcliffe calculées sont nettement supérieures à 70% et les coefficients de corrélation de Pearson sont très élevés et supérieurs à 0,80. Mais, malgré ces bonnes performances, les débits extrêmes sont généralement mal modélisés.Mots-clés : modélisation, apprentissage, perceptron multicouches, rivière

Optimisation and validation of hydrogel-based brain tissue clearing shows uniform expansion across anatomical regions and spatial scales

Imaging of fxed tissue is routine in experimental neuroscience, but is limited by the depth of tissue that can be imaged using conventional methods. Optical clearing of brain tissue using hydrogelbased methods (e.g. CLARITY) allows imaging of large volumes of tissue and is rapidly becoming commonplace in the feld. However, these methods sufer from a lack of standardized protocols and validation of the efect they have upon tissue morphology. We present a simple and reliable protocol for tissue clearing along with a quantitative assessment of the efect of tissue clearing upon morphology. Tissue clearing caused tissue swelling (compared to conventional methods), but this swelling was shown to be similar across spatial scales and the variation was within limits acceptable to the feld. The results of many studies rely upon an assumption of uniformity in tissue swelling, and by demonstrating this quantitatively, research using these methods can be interpreted more reliably