1,895 research outputs found

    It is not good to talk : conversation has a fixed interference cost on attention regardless of difficulty

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    It is well-documented that telephone conversations lead to impaired driving performance. Kunar et al. (Psychon Bull Rev 15:1135–1140, 2008) showed that this deficit was, in part, due to a dual-task cost of conversation on sustained visual attention. Using a multiple object tracking (MOT) task they found that the act of conversing on a hands-free telephone resulted in slower response times and increased errors compared to when participants performed the MOT task alone. The current study investigates whether the dual-task impairment of conversation on sustained attention is affected by conversation difficulty or task difficulty, and whether there was a dual-task deficit on attention when participants overheard half a conversation. Experiment 1 manipulated conversation difficulty by asking participants to discuss either easy questions or difficult questions. The results showed that there was no difference in the dual-task cost depending on conversation difficulty. Experiment 2 showed a similar dual-task deficit of attention in both an easy and a difficult visual search task. Experiments 3 and 4 showed that in contrast to work using a dot tracking and choice reaction time task (Emberson et al., Psychol Sci 21:1383–1388, 2010), there was little deficit on MOT performance of hearing half a conversation, provided people heard the conversations in their native language. The results are discussed in terms of a resource-depleted account of attentional resources showing a fixed conversational-interference cost on attention

    Oil recovery through deemulsification research : separation of water from emulsified oil

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    In an effort to improve the environment, there is a need to recover and reuse the oil and water components of lubricating emulsions used in copper drawing and rolling processes. The Freeport-McMoRan Copper and Gold Inc. copper rod mill located in El Paso, TX was chosen as the site location for this project. It is one of the largest rolling and drawing operation facilities in the world, and it meets the established criteria set by Project ORDER. A large facility generates an average of 8,400 gallons of spent lubricant per day. The WERC emulsion sample contains 98 v% water and 2 v% lubricating oil and contains metal debris that would negatively impact water quality if it were discharged into surface waters. Oil and water are valuable resources and their maximum recoveries are desired. Project ORDER successfully recovers more than 90 v% of the water and essentially all of the oil. The recovered water could be recycled for fresh lubricant production within the facility, eliminating almost all water discharge and reducing water intake. The recovered oil will be sent to oil recyclers, lowering discharge expenses. Project ORDER has carefully evaluated several water recovery, oil recovery, and metal recovery technologies to design the commercial process. The first processing step of Project ORDER is an ultrafiltration (UF) membrane that recovers 90 v% of the water in the spent emulsion sample. As water permeates the membrane, the concentration of oil in the emulsion increases from about 2 v% to 30 v%. The second processing step removes essentially all of the water from the UF concentrate using an evaporator, which operates by passing low pressure steam through a jacketed, agitated vessel. The third processing step removes metal debris from the oil using a depth filter. The fourth processing step utilizes a reverse osmosis (RO) membrane to purify the UF permeate water for recycle. The fifth processing step reduces the amount of waste from the RO reject using an evaporator, which also operates by passing low pressure steam through a jacketed, agitated vessel. The evaporator removes essentially all of the water in the RO reject and the remaining waste is sent for disposal. The evaporated water from both evaporation units is condensed and combined with the RO permeate to be recycled. Based on a spent emulsion production rate of 8,400 gal/day, it costs 793,000peryearforcurrentdisposalbyincineration.ForProjectORDERthefixedcapitalinvestmentis793, 000 per year for current disposal by incineration. For Project ORDER the fixed capital investment is 899,000, the yearly operating cost is 528,000,andthenetpresentworthis528,000, and the net present worth is 413,000 with a 24% discounted rate of return. After the initial investment is recovered, Project ORDER results in a net savings of $265,000 per year. This project is a promising process to achieve all the goals of Task 5. It produces oil with less than 3% water content, produces maximum water yield, minimizes waste solution, avoids the use of harmful materials and is cost and energy efficient. The health and safety of all individuals involved and the environmental impact of Project ORDER is of utmost importance throughout the construction and life of the project. The facility will ensure that all processes will comply with regulations outlined by the Environmental Protection Agency (EPA), Occupational Safety and Health Administration (OSHA), the Resource Conservation and Recovery Act (RCRA), and Texas State and El Paso County regulations. All operations and company procedures will comply with The Emergency Planning and Community Right-to-Know Act of 1986. The following report provides a detailed proposal for an oil and water recovery system, including experimental research results, process optimization, full-scale design, economic analysis, and environmental, health and safety considerations

    Nephrotoxicity During Vancomycin Therapy in Combination with Piperacillin-Tazobactam or Cefepime

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    Recent reports have demonstrated that vancomycin (VAN) may lead to an increase in the incidence of acute kidney injury (AKI) when it is combined with antipseudomonal beta-lactams. This study compared the incidence of AKI associated with VAN plus piperacillin-tazobactam (TZP) or cefepime (FEP). This was a retrospective, matched cohort study that was conducted at an academic medical center between September 2010 and September 2014 and that included adult patients without severe chronic or structural kidney disease, dialysis, pregnancy, cystic fibrosis, or a hospital transfer receiving TZP-VAN or FEP-VAN for at least 48 h. The primary outcome was the difference in the AKI incidence between the TZP-VAN and FEP-VAN groups, evaluated using the risk, injury, failure, loss of kidney function, and end-stage kidney disease (RIFLE) criteria. Patients in the two groups were matched on the basis of age, sex, severity of illness, baseline creatinine clearance, hypotension, number of nephrotoxicity risk factors, and intravenous contrast exposure. In total, 4,193 patients met all inclusion criteria (3,605 received TZP-VAN and 588 received FEP-VAN). The unadjusted AKI incidence was 21.4% in patients receiving TZP-VAN, whereas it was 12.6% in patients receiving FEP-VAN (P \u3c 0.001). After the patients were matched, 1,633 patients receiving TZP-VAN and 578 patients receiving FEP-VAN were evaluated. The AKI incidence remained higher in patients receiving TZP-VAN than in those receiving FEP-VAN (21.4% versus 12.5%, P \u3c 0.0001). This trend remained true for all classifications of the RIFLE criteria. After controlling for remaining confounders, TZP-VAN therapy was associated with 2.18 times the odds of AKI than FEP-VAN therapy (95% confidence interval, 1.64 to 2.94 times) in logistic regression. AKI was significantly more common in patients receiving vancomycin in combination with piperacillin-tazobactam than in those receiving vancomycin in combination with cefepime. This finding reinforces the need for the judicious use of combination empirical antimicrobial therapy

    Violent victimization among immigrants: Using the National Violent Death Reporting System to examine foreign-born homicide victimization in the United States

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    Limited research attention has focused on homicides involving foreign-born victims. Using data from the National Violent Death Reporting System, we examined 9428 homicides that occurred in 2017 in the United States across 32 states and D.C. Approximately 8% of homicide victims were foreign-born. Homicide victimization rates were substantially lower for foreign-born persons, compared to U.S.-born persons. However, foreign-born persons from Honduras, El Salvador, and Jamaica had a substantially higher risk of homicide victimization. Notably, few homicides involving foreign-born victims were gang- or drug-trade-related. With the growing number of immigrants in the United States, policy and prevention efforts should be guided by research

    An automated machine learning approach to predict brain age from cortical anatomical measures

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    The use of machine learning (ML) algorithms has significantly increased in neuroscience. However, from the vast extent of possible ML algorithms, which one is the optimal model to predict the target variable? What are the hyperparameters for such a model? Given the plethora of possible answers to these questions, in the last years, automated ML (autoML) has been gaining attention. Here, we apply an autoML library called Tree-based Pipeline Optimisation Tool (TPOT) which uses a tree-based representation of ML pipelines and conducts a genetic programming-based approach to find the model and its hyperparameters that more closely predicts the subject's true age. To explore autoML and evaluate its efficacy within neuroimaging data sets, we chose a problem that has been the focus of previous extensive study: brain age prediction. Without any prior knowledge, TPOT was able to scan through the model space and create pipelines that outperformed the state-of-the-art accuracy for Freesurfer-based models using only thickness and volume information for anatomical structure. In particular, we compared the performance of TPOT (mean absolute error [MAE]: 4.612 ± .124 years) and a relevance vector regression (MAE 5.474 ± .140 years). TPOT also suggested interesting combinations of models that do not match the current most used models for brain prediction but generalise well to unseen data. AutoML showed promising results as a data-driven approach to find optimal models for neuroimaging applications

    Radial Star Formation Histories in 32 Nearby Galaxies

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    The spatially resolved star formation histories are studied for 32 normal star-forming galaxies drawn from the the Spitzer Extended Disk Galaxy Exploration Science survey. At surface brightness sensitivities fainter than 28 mag arcsec−2^{-2}, the new optical photometry is deep enough to complement archival ultraviolet and infrared imaging and to explore the properties of the emission well beyond the traditional optical extents of these nearby galaxies. Fits to the spectral energy distributions using a delayed star formation history model indicate a subtle but interesting average radial trend for the spiral galaxies: the inner stellar systems decrease in age with increasing radius, consistent with inside-out disk formation, but the trend reverses in the outermost regions with the stellar age nearly as old as the innermost stars. These results suggest an old stellar outer disk population formed through radial migration and/or the cumulative history of minor mergers and accretions of satellite dwarf galaxies. The subset of S0 galaxies studied here show the opposite trend compared to what is inferred for spirals: characteristic stellar ages that are increasingly older with radius for the inner portions of the galaxies, and increasingly younger stellar ages for the outer portions. This result suggests that either S0 galaxies are not well modeled by a delayed-τ\tau model, and/or that S0 galaxies have a more complicated formation history than spiral galaxies.Comment: Accepted for publication in the Astronomical Journal. arXiv admin note: text overlap with arXiv:1511.0328
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