Strategies for Using a Spatial Method to Promote Active Learning of Probability Concepts

We developed and tested strategies for using spatial representations to help students understand core probability concepts, including the multiplication rule for computing a joint probability from a marginal and conditional probability, interpreting an odds value as the ratio of two probabilities, and Bayesian inference. The general goal of these strategies is to promote active learning by introducing concepts in an intuitive spatial format and then encouraging students to try to discover the explicit equations associated with the spatial representations. We assessed the viability of the proposed active-learning approach with two exercises that tested undergraduates’ ability to specify mathematical equations after learning to use the spatial solution method. A majority of students succeeded in independently discovering fundamental mathematical concepts underlying probabilistic reasoning. For example, in the second exercise, 76% of students correctly multiplied marginal and conditional probabilities to find joint probabilities, 86% correctly divided joint probabilities to get an odds value, and 69% did both to achieve full Bayesian inference. Thus, we conclude that the spatial method is an effective way to promote active learning of probability equations

Safety and Mobility Analysis of Rolling Slowdown for Work Zones: Comparison with Full Closure

There are times when the traffic lanes through a work zone must be kept clear for activities such as placing overhead beams, erecting overhead signs, and installing power lines, and other temporary roadway work activities. As an alternative to a full road closure, a rolling slowdown can typically provide up to 30 minutes to complete such activities without bringing approaching traffic to a complete halt. Using data from recent rolling slowdowns and full closures carried on the Indiana interstate network and a simulation approach, this study compares rolling slowdowns to full closures from safety and mobility standpoints. The study suggests that while rolling slowdowns are more impactful in terms of travel times, they are a safer option than full closures as they often form a forward moving shockwave causing, lower hard braking rates, and consequently a lower probability of causing a crash

Integrated One-Dimensional Modeling of Asphaltene Deposition in Wellbores/Pipelines

—Asphaltene deposition in wellbores/pipelines causes serious production losses in the oil and gas industry. This work presents a numerical model to predict asphaltene deposition in wellbores/pipelines. This model consists of two modules: a Thermodynamic Module and a Transport Module. The Thermodynamic Module models asphaltene precipitation using the Peng-Robinson Equation of State with Peneloux volume translation (PR-Peneloux EOS). The Transport Module covers the modeling of fluid transport, asphaltene particle transport and asphaltene deposition. These modules are combined via a thermodynamic properties lookup-table generated by the Thermodynamic Module prior to simulation. In this work, the Transport Module and the Thermodynamic Module are first verified and validated separately. Then, the integrated model is applied to an oilfield case with asphaltene deposition problem where a reasonably accurate prediction of asphaltene deposit profile is achieve

Early warning device for detection of pollutants in water

Due to a growing need to protect water resources from contamination, there is a requirement for the development of more reliable and cost effective devices for water quality monitoring. The aim of the AQUAWARN project is to develop and deploy a fully autonomous water quality monitoring device that can measure nitrite, nitrate, phosphate and pH colorimetrically in fresh water and wastewater, and communicate the information to stakeholders in real time

Early warning pollution detection device for application in water quality

It has been well recognised that water is a valuable resource and the quality of our water systems require sampling at a higher temporal and spatial frequency than is currently taking place. The AQUAWARN project aims to meet this challenge through the development of commercially competitive water quality monitoring devices. These will be capable of performing analytical measurements in situ - primarily aimed at freshwater and wastewater systems. The analytes of interest are mainly phosphate, nitrite, nitrate, and pH. The initial focus of this project is the assessment and optimisation of appropriate colorimetric chemistries for each sensing target. These chemistries have been developed and optimised using bench-top instrumentation. Integration within microfluidic chips followed to reduce the per sample costs. Microfluidic technology uses minute amounts of reagent per sample measurement, allowing for a dramatic increase in the number of potential assays per unit volume of reagent. Moreover, the integration of LEDs and photodiodes as light sources and detectors, coupled with syringe pumps, opens the way to new generations of low-cost, portable, and autonomous devices, capable of performing multiple in-situ measurements.  For example, an analysis requiring 50 uL of reagent implies 2,000 measurements are possible per 100 mL of reagent

Factores de riesgo de mortalidad en pacientes que presentaron peritonitis en diálisis peritoneal crónica en el Hospital Militar Central de Bogotá

In Colombia, chronic peritoneal dialysis (CPD) is one of the most common forms of onset of chronic renal replacement therapy. Complications associated with therapy are low. However, the peritonitis associated with CKD has been related to change from therapeutic mode to chronic hemodialysis with increased hospitalization rates. A case-control study was performed to evaluate the mortality and risk factors associated in patients who presented peritonitis in CPS in the period from January 1st of 2010 to December 31st of 2012. The risk factors identified for the development of peritonitis and mortality were not statistically significant. The cases of peritonitis attributed to fatigue of the caregiver presented an increased risk of recurrence and relapse. In regard to the risk of mortality it was found to be 1.75 times greater in men, 1.6 times higher in males, 2.2 times greater in patients older than 75 years, 3.5 times higher in diabetic patients and 5.6 timeshigher in hypertensive patients.La diálisis peritoneal crónica (DPC) es una de las opciones más frecuentes de inicio de terapia de remplazo renal crónico en Colombia. La presencia de complicaciones inherentes a la terapia tiene baja incidencia, sin embargo, la peritonitis asociada con DPC se ha relacionado con el posterior cambio de modalidad terapéutica a hemodiálisis crónica y con aumento de las tasas de hospitalización. Se desarrolló un estudio de casos y controles con el fin de evaluar la mortalidad y posibles factores de riesgo asociados en los pacientes que presentaron peritonitis en DPC en el periodo comprendido entre el 1 de enero de 2010 y el 31 de diciembre de 2012.Los factores de riesgo identificados para desarrollo de peritonitis y mortalidad no tuvieron significancia estadística. Los casos de peritonitis atribuidos a fatiga del cuidador, presentaron mayor riesgo de recurrencia y recaída de la peritonitis. En cuanto al riesgo de mortalidad se encontró que la probabilidad para la presentación de dicho desenlace fue 1,75 veces mayor en los hombres, 2.2 veces mayor en los pacientes mayores de 75 años, 3.5 veces mayor en los diabéticos y 5.6 veces más elevado en los pacientes hipertensos

Three Dimensional Measurements of Asphaltene Deposition in a Transparent Micro-Channel

This study describes a novel experimental approach to directly measure the thicknesses of asphaltene deposits in micro-channels. The thickness of the asphaltene deposit is estimated using a visualization technique based on 3D digital microscopy. The working fluid is a mixture of n-heptane and dead oil. Induced by the addition of n-heptane, the asphaltenes present in crude oil phase separate at ambient temperature to form aggregates of asphaltene-rich phase. Part of the asphaltene aggregates deposit on the walls of the transparent micro-channel. A two-dimensional profile of the deposit across the channel at selected axial sections is measured. The influences of injection mixture volume on the growth of the thickness of deposited asphaltenes is investigated using two experimental conditions, (i) varying elapsed time at constant flow rate and (ii) increasing the flow rate at a constant elapsed time. In both cases the deposit thickness of asphaltene (δ) increases with the total injection volume (V). The experimental results obtained in this work provide new insights into the deposition process at the micro-scale level, which can be used to facilitate the development of more accurate numerical model for this applicatio

Tamarix minoa (Tamaricaceae), a new species from the island of Crete (Greece) based on morphological and plastid molecular sequence data

Tamarix minoa is described from material collected on the S Aegean island of Crete (Kriti), Greece. A morphological comparison with the species considered to be closest, T. africana and T. hampeana, is provided. An original illustration showing the main morphological characters of the new species is also given, as are photographs of the new species in its habitat. The isolated phylogenetic position of T. minoa is shown to be strongly supported by plastid molecular sequence data (trnS-trnG, trnQ-rps16 and ndhF-rpl32), thus warranting its recognition at specific rank.National Geographic Society, research project “Human recreation versus plant diversity on maritime sands in Crete” (NGS grant no. 8573-08). The FPU programme (Mº de Educación, Spain), the I+D+I project CGL2008-05056 (Mº de Educación y Ciencia, Spanish Government), the project OAPN 354-2011 (Mº de Agricultura, Alimentación y Medio Ambiente, Spanish Government) and complementary supporting funds ACIE10-01, ACIE11-05 and ACIE13-08 (University of Alicante, Spain)

Infection importation: a key challenge to malaria elimination on Bioko Island, Equatorial Guinea.

BACKGROUND: The impact of importation of falciparum malaria from mainland Equatorial Guinea on malaria infection in non-travellers and travellers on Bioko Island was examined. METHODS: Malaria indicator surveys were conducted in 2013 and 2014 to assess the association between malaria infection and travel to the mainland. Infection in non-travellers was compared in neighbourhoods of high travel and neighbourhoods of low travel. Boat passengers leaving from and arriving on the island were tested for infection. RESULTS: Children who had travelled to the mainland in the previous eight weeks were at greater risk of infection than those who had not travelled (56 vs 26% in 2013; 42 vs 18% in 2014). Children who had not travelled, living in localities with the highest proportion of travellers, were significantly more likely to be infected compared to those in localities with the smallest proportion of travellers (adjusted odds ratios 7.7 (95% CI 2.3-25) and 5.3 (95% CI 2.5-11) in 2013 and 2014, respectively). Infection in arriving boat passengers was substantially higher than in those departing (70 vs 38%, p = 0.017). DISCUSSION: Malaria importation by travellers poses a serious public health challenge affecting non-travellers as well as travellers

Different involvement of medial prefrontal cortex and dorso-lateral striatum in automatic and controlled processing of a future conditioned stimulus

Recent studies support the idea that stimulus processing in latent inhibition can vary during the course of preexposure. Controlled attentional mechanisms are said to be important in the early stages of preexposure, while in later stages animals adopt automatic processing of the stimulus to be used for conditioning. Given this distinction, it is possible that both types of processing are governed by different neural systems, affecting differentially the retrieval of information about the stimulus. In the present study we tested if a lesion to the dorso-lateral striatum or to the medial prefrontal cortex has a selective effect on exposure to the future conditioned stimulus (CS). With this aim, animals received different amounts of exposure to the future CS. The results showed that a lesion to the medial prefrontal cortex enhanced latent inhibition in animals receiving limited preexposure to the CS, but had no effect in animals receiving extended preexposure to the CS. The lesion of the dorso-lateral striatum produced a decrease in latent inhibition, but only in animals with an extended exposure to the future conditioned stimulus. These results suggest that the dorsal striatum and medial prefrontal cortex play essential roles in controlled and automatic processes. Automatic attentional processes appear to be impaired by a lesion to the dorso-lateral striatum and facilitated by a lesion to the prefrontal cortex.Ministerio de Economía, Industria y Competitividad PSI2015-65500-