293 research outputs found

    Inferring networks from time series: a neural approach

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    Network structures underlie the dynamics of many complex phenomena, from gene regulation and foodwebs to power grids and social media. Yet, as they often cannot be observed directly, their connectivities must be inferred from observations of their emergent dynamics. In this work we present a powerful and fast computational method to infer large network adjacency matrices from time series data using a neural network. Using a neural network provides uncertainty quantification on the prediction in a manner that reflects both the non-convexity of the inference problem as well as the noise on the data. This is useful since network inference problems are typically underdetermined, and a feature that has hitherto been lacking from network inference methods. We demonstrate our method's capabilities by inferring line failure locations in the British power grid from observations of its response to a power cut. Since the problem is underdetermined, many classical statistical tools (e.g. regression) will not be straightforwardly applicable. Our method, in contrast, provides probability densities on each edge, allowing the use of hypothesis testing to make meaningful probabilistic statements about the location of the power cut. We also demonstrate our method's ability to learn an entire cost matrix for a non-linear model from a dataset of economic activity in Greater London. Our method outperforms OLS regression on noisy data in terms of both speed and prediction accuracy, and scales as N2N^2 where OLS is cubic. Since our technique is not specifically engineered for network inference, it represents a general parameter estimation scheme that is applicable to any parameter dimension

    Using Wearable Devices for Non-invasive, Inexpensive Physiological Data Collection

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    Using sensors to gather physiological data about users can provide valuable insights for Information Systems (IS) research that are not availed through traditional measures. While useful in many laboratory settings, many of these physiological sensors (e.g., fMRI, EEG, EKG, etc.) are impractical and severely limited in other scenarios due to (1) prohibitive cost, (2) small sample size, (3) invasiveness, and (4) the difficulty to match psychological traits to physiological measures. In this study, we demonstrate how inexpensive consumer-grade wearable technologies overcome these first three limitations while we extend existing research on exploring the fourth limitation

    The Nutrition Education Initiative Resource Guide: Examining Effectiveness with Middle School Students and Perceptions of Science Teachers

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    Background and Purpose: With obesity in children and youth continuing to be a major health problem in the U.S., schools are considered an important setting to implement programs to address the issue but few have focused on middle school students. The purposes of this study were to: 1) determine the effectiveness of a school-based nutrition education program, the Nutrition Education Initiative (NEI) Resource Guide, in improving school lunch eating behaviors of middle school students, and 2) identify science teachers’ perceptions of the materials. Implementation: The project was implemented by 16 middle school science teachers and 309 seventh grade students in a medium-sized north Florida community. The NEI Guide included three conceptual areas (Build a Healthy Base, Choose Sensibly and Aim for Fitness), major concepts, objectives, narrative information, and teaching strategies. Evaluation: Using a pre-/post without control group design, the study involved collecting data via food recall surveys with students, and surveys and interviews with teachers. Data were analyzed using descriptive statistics and paired t-tests. Results: During lunch time, a higher proportion of students met the recommended dietary servings for dairy, meat, vegetables, fruit, juice and grains from pre-test to post-test. Students also significantly increased dietary intake of meat (p< .01), fruit (p< .01) and fruit/juice combined (p< .05); and significantly decreased intake of fried vegetables (p< .001), with decreased fat intake approaching significance (p< .06). Differences in dietary patterns were noted between the two schools studied. Science teachers perceived the NEI Guide as effective; yet they also identified challenges including lack of adequate training, lack of time to implement the materials, and lack of collaboration with the project team. Conclusion: The project outcomes suggest that middle school science teachers can positively impact school lunch eating behaviors of middle school students in selected schools by incorporating nutrition education in their curricula

    "The Business Case for Racial Equity" Quantifies the Cost of Racism in the U.S.

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    Altarum Institute and the W.K. Kellogg Foundation (WKKF) released a report detailing the economic impact of racism, and the benefits of advancing racial equity as the demography of our nation continues to evolve

    The Business Case for Racial Equity, 2013

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    Striving for racial equity -- a world where race is no longer a factor in the distribution of opportunity -- is a matter of social justice. But moving toward racial equity can generate significant economic returns as well. When people face barriers to achieving their full potential, the loss of talent, creativity, energy, and productivity is a burden not only for those disadvantaged, but for communities, businesses, governments, and the economy as a whole. Initial research on the magnitude of this burden in the United States (U.S.), as highlighted in this brief, reveals impacts in the trillions of dollars in lost earnings, avoidable public expenditures, and lost economic output

    Caesarean section for non-medical reasons at term

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    Background: Caesarean section rates are progressively rising in many parts of the world. One suggested reason is increasing requests by women for caesarean section in the absence of clear medical indications, such as placenta praevia, HIV infection, contracted pelvis and, arguably, breech presentation or previous caesarean section. The reported benefits of planned caesarean section include greater safety for the baby, less pelvic floor trauma for the mother, avoidance of labour pain and convenience. The potential disadvantages, from observational studies, include increased risk of major morbidity or mortality for the mother, adverse psychological sequelae, and problems in subsequent pregnancies, including uterine scar rupture and greater risk of stillbirth and neonatal morbidity. An unbiased assessment of advantages and disadvantages would assist discussion of what has become a contentious issue in modern obstetrics. Objectives: To assess, from randomised trials, the effects on perinatal and maternal morbidity and mortality, and on maternal psychological morbidity, of planned caesarean delivery versus planned vaginal birth in women with no clear clinical indication for caesarean section. Search methods: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (April 2009). Selection criteria: All comparisons of intention to perform caesarean section and intention for women to give birth vaginally; random allocation to treatment and control groups; adequate allocation concealment; women at term with single fetuses with cephalic presentations and no clear medical indication for caesarean section. Data collection and analysis: We identified no studies that met the inclusion criteria. Main results: There were no included trials. Authors' conclusions: There is no evidence from randomised controlled trials, upon which to base any practice recommendations regarding planned caesarean section for non-medical reasons at term. In the absence of trial data, there is an urgent need for a systematic review of observational studies and a synthesis of qualitative data to better assess the short- and long-term effects of caesarean section and vaginal birth

    Establishment and Spread of a Single Parthenogenic Genotype of the Mediterranean arundo wasp, Tetramesa romana1, In the Variable Climate of Texas

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    As part of a biological control program for the invasive weed, Arundo donax L., several genotypically unique populations of the parthenogenetic stemgalling wasp, Tetramesa romana Walker (Hymenoptera: Eurytomidae), from Spain and France were released in an infested riparian zone along the Rio Grande from Brownsville to Del Rio, TX. An adventive population of the wasp of unknown origin with limited distribution in Texas was also discovered, evaluated, and released as part of the program. More than 1.2 million wasps representing the mixture of genotypes were aerially released from 2009 to 2011. Wasps dispersed from their original release locations and now have a continuous distribution along the Rio Grande from Brownsville to Del Rio, and have dispersed throughout most of Central Texas with satellite populations as far west as San Angelo (Tom Green County), north as far as Kaufman (Kaufman County), and east to Navasota (Grimes County). The most successful genotype (#4) represented 390 of the 409 wasps recovered and matched both an imported population from the Mediterranean coast of Spain and an adventive population established in Texas before the start of the biological control program. Several other European genotypes of the wasp released in the program apparently failed to establish. This result demonstrated the benefits of evaluating and releasing the maximum genetic diversity of the biological control agent in the introduced range. Abundance of T. romana on the Rio Grande from Laredo to Del Rio averaged 190% more in 2013-2014 compared to a similar study in 2008-2009 before release of the European wasps. A favorability index was developed that showed that conditions from 1969 to 1977 would have been adverse to the wasp; conditions after 2009 were more favorable. Climate matching predicts the wasp will disperse throughout the southern U.S. and Mexico

    EvoFIT composite face construction via practitioner interviewing and a witness-administered protocol

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    Police require reliable facial-composite systems to help identify, arrest and convict criminals. Recent developments, however, have allowed newer versions of the EvoFIT composite system to be made available for policing. The outcome is an online (cloud-based) version and a new system called Witness At Home, both using a simpler interface. Here, we formally compare these two versions to establish potential benefits to policing. Two experiments were conducted. In Experiment 1, participants observed a target identity for 1 minute and returned 4 hours (Witness At Home) or 24 hours (EvoFIT Online) to construct a composite from memory. No significant difference in composite accuracy was found. In Experiment 2, participants constructed a composite, 24-hours after seeing a target identity, using either EvoFIT Online or Witness At Home. A significant increase in accurate identification was found for EvoFIT Online, with some utility for the self-administered procedure, together indicating benefit for these newer systems plus some areas for development

    The oxidative degradation of phenol via in situ H2O2 synthesis using Pd supported Fe-modified ZSM-5 catalysts

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    The oxidative degradation of organic contaminants via the in situ synthesis of H2O2 from dilute streams of H2 and O2 has the potential to significantly reduce the detrimental environmental and health effects associated with the discharge of such pollutants into water bodies, while offering enhanced activity compared to traditional approaches to water treatment. Herein we investigate the efficacy of a series of bifunctional Pd/Fe-ZSM-5 catalysts towards the degradation of phenol, a model wastewater contaminant, where Fe is responsible for the generation of highly reactive oxygen-based species (ROS) from the synthesised H2O2. In particular we demonstrate that through control of Fe speciation and Pd oxidation state it is possible to achieve total conversion of phenol and its derivatives, while also making substantial improvements in regard to catalyst stability over previously studied materials
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