Peer-review in a world with rational scientists: Toward selection of the average

One of the virtues of peer review is that it provides a self-regulating selection mechanism for scientific work, papers and projects. Peer review as a selection mechanism is hard to evaluate in terms of its efficiency. Serious efforts to understand its strengths and weaknesses have not yet lead to clear answers. In theory peer review works if the involved parties (editors and referees) conform to a set of requirements, such as love for high quality science, objectiveness, and absence of biases, nepotism, friend and clique networks, selfishness, etc. If these requirements are violated, what is the effect on the selection of high quality work? We study this question with a simple agent based model. In particular we are interested in the effects of rational referees, who might not have any incentive to see high quality work other than their own published or promoted. We find that a small fraction of incorrect (selfish or rational) referees can drastically reduce the quality of the published (accepted) scientific standard. We quantify the fraction for which peer review will no longer select better than pure chance. Decline of quality of accepted scientific work is shown as a function of the fraction of rational and unqualified referees. We show how a simple quality-increasing policy of e.g. a journal can lead to a loss in overall scientific quality, and how mutual support-networks of authors and referees deteriorate the system.Comment: 5 pages 4 figure

Development of improved plastic foam generating agents and techniques for Saturn applications Final report, Jul. 1964 - Jun. 1965

Foam system compressive strength analysis, solid urethane castings to screen polymer systems, and prepolymer methods of foam preparation in plastic foam development for Saturn projec

UT Health RGV COVID-19 Testing Report

Purpose: This health surveillance project\u27s goal was to organize de-identified data received from UT Health RGV with the intent to provide timely reporting to testing sites and health affairs directors. We aimed to explore how testing rates differ between counties, testing sites and age groups from March 30 through August 7, 2020. We looked at different demographics and compared the positivity rates for each testing site. For this report, we will detail information for the pediatric population (ages 0-18). Materials and Methods: A codebook and database were created with information about COVID-19 test data to formulate reports to the testing sites and directors. We used SPSS software to run descriptive statistics and preliminary analysis to help visualize the data. Results: Based on the American Academy of Pediatrics report on August 13, 2020, Texas only provides pediatric age distribution for 8% of their test results. Based on our data from the Rio Grande Valley, we can aid in reporting test results that included pediatrics demographics. We found that 40.6% (N=1016) of patients 18 or younger at time of testing tested positive (compared to the national average of 3.6-18.3%), 5.7% of total tests were done on patients 18 or younger (compared to 3-12% nationally), and 7.8% of our positive cases were in patients 18 or younger (compared to 9.1% nationally). By county, the positivity rates for COVID-19 testing were as follows: Cameron = 29.8% (N=6379), Hidalgo = 29.3% (N=11249), Starr = 14.3%(N=63), Willacy = 27.3% (N=99), Other TX = 14.3% (N=112), Out of state = 16.7% (N=54). Test positivity by testing site was: Edinburg = 28.7% (N=9637), Mercedes = 30.3% (N=2840), Harlingen = 31.6% (N=3377), Brownsville = 26.8% (N=2102). Limitations: Not all data is from unique individuals; this database includes retested individuals. Therefore, data results should be interpreted with caution. Additionally, when patients selected their race and ethnicity, the race options included all of the major races, yet ethnicity was limited to the Hispanic/Latino race and a blanket option for “non-Hispanic/Latino”, without the ability to choose other ethnicities. Interpreting data about ethnicity is therefore limited. Discussion: Further analysis is needed to identify patients retested. A data subset of retested individuals will provide accurate test positivity rate. Overall, the database can provide insightful pediatric data to establish rates of pediatric COVID-19 infections in South Texas. We hope that the data and analysis provided can help inform legislative decision making

Modelling Knudsen number effects in suspension high velocity oxy fuel thermal spray

Suspension high velocity oxy fuel thermal spray is a system characterized by supersonic velocities and length scales of particles of the order of nm – µm. As the effects of rarefication become significant the assumptions within the continuum models begin to collapse, the effects of rarefication can be evaluated through the flow Knudsen number. Modifications to the numerical modelling must be made to incorporate the effects of rarefaction. This study looks to include the effects of rarefication into the computational fluid dynamics (CFD) models for the suspension high velocity oxy-fuel (SHVOF) thermal spray process. A model for the heat transfer coefficient that take into account the Knudsen and Mach number effects is employed. Finally, the Ranz-Marshall correlation for the Nusselt number is compared to the Kavanau correlation and a compressible Nusselt number correlation. The model is validated through comparisons of particle temperatures which are obtained from two colour pyrometry measurements using a commercially available Accuraspray 4.0 diagnostic system. This study shows that there is a significant improvement in the prediction of inflight particle temperatures when accounting for the effects of compressibility and the effects of rarefication on the Nusselt number

Extended Timed Up and Go assessment as a clinical indicator of cognitive state in Parkinson\u27s disease

Objective: To evaluate a modified extended Timed Up and Go (extended-TUG) assessment against a panel of validated clinical assessments, as an indicator of Parkinson’s disease (PD) severity and cognitive impairment. Methods: Eighty-seven participants with idiopathic PD were sequentially recruited from a Movement Disorders Clinic. An extended-TUG assessment was employed which required participants to stand from a seated position, walk in a straight line for 7 metres, turn 180 degrees and then return to the start, in a seated position. The extended-TUG assessment duration was correlated to a panel of clinical assessments, including the Unified Parkinson’s Disease Rating Scale (MDS-UPDRS), Quality of Life (PDQ-39), Scales for Outcomes in Parkinson’s disease (SCOPA-Cog), revised Addenbrooke’s Cognitive Index (ACE-R) and Barratt’s Impulsivity Scale 11 (BIS-11). Results: Extended-TUG time was significantly correlated to MDS-UPDRS III score and to SCOPA-Cog, ACE-R (p\u3c0.001) and PDQ-39 scores (p\u3c0.01). Generalized linear models determined the extended-TUG to be a sole variable in predicting ACE-R or SCOPA-Cog scores. Patients in the fastest extended-TUG tertile were predicted to perform 8.3 and 13.4 points better in the SCOPA-Cog and ACE-R assessments, respectively, than the slowest group. Patients who exceeded the dementia cut-off scores with these instruments exhibited significantly longer extended-TUG times. Conclusions: Extended-TUG performance appears to be a useful indicator of cognition as well as motor function and quality of life in PD, and warrants further evaluation as a first line assessment tool to monitor disease severity and response to treatment. Poor extended-TUG performance may identify patients without overt cognitive impairment form whom cognitive assessment is needed

A Study on the Parallelization of Terrain-Covering Ant Robots Simulations

Agent-based simulation is used as a tool for supporting (time-critical) decision making in differentiated contexts. Hence, techniques for speeding up the execution of agent-based models, such as Parallel Discrete Event Simulation (PDES), are of great relevance/benefit. On the other hand, parallelism entails that the final output provided by the simulator should closely match the one provided by a traditional sequential run. This is not obvious given that, for performance and efficiency reasons, parallel simulation engines do not allow the evaluation of global predicates on the simulation model evolution with arbitrary time-granularity along the simulation time-Axis. In this article we present a study on the effects of parallelization of agent-based simulations, focusing on complementary aspects such as performance and reliability of the provided simulation output. We target Terrain Covering Ant Robots (TCAR) simulations, which are useful in rescue scenarios to determine how many agents (i.e., robots) should be used to completely explore a certain terrain for possible victims within a given time. © 2014 Springer-Verlag Berlin Heidelberg

Entanglement between static and flying qubits in quantum wires

A weakly bound electron in a semiconductor quantum wire is shown to become entangled with an itinerant electron via the coulomb interaction. The degree of entanglement and its variation with energy of the injected electron, may be tuned by choice of spin and initial momentum. Full entanglement is achieved close to energies where there are spin-dependent resonances. Possible realisations of related device structures are discussed

A Hartree-Fock Study of Persistent Currents in Disordered Rings

For a system of spinless fermions in a disordered mesoscopic ring, interactions can give rise to an enhancement of the persistent current by orders of magnitude. The increase in the current is associated with a charge reorganization of the ground state. The interaction strength for which this reorganization takes place is sample-dependent and the log-averages over the ensemble are not representative. In this paper we demonstrate that the Hartree-Fock method closely reproduces results obtained by exact diagonalization. For spinless fermions subject to a short-range Coulomb repulsion U we show that due to charge reorganization the derivative of the persistent current is a discontinuous function of U. Having established that the Hartree-Fock method works well in one dimension, we present corresponding results for persistent currents in two coupled chains.Comment: 4 pages, 6 figures, Submitted to Phys. Rev.