16,552 research outputs found

    On-line multiobjective automatic control system generation by evolutionary algorithms

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    Evolutionary algorithms are applied to the on- line generation of servo-motor control systems. In this paper, the evolving population of controllers is evaluated at run-time via hardware in the loop, rather than on a simulated model. Disturbances are also introduced at run-time in order to pro- duce robust performance. Multiobjective optimisation of both PI and Fuzzy Logic controllers is considered. Finally an on-line implementation of Genetic Programming is presented based around the Simulink standard blockset. The on-line designed controllers are shown to be robust to both system noise and ex- ternal disturbances while still demonstrating excellent steady- state and dvnamic characteristics

    Do Natural Disasters Affect Trust/Trustworthiness? Evidence from the 2010 Chilean Earthquake

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    A series of trust games were conducted in Chile to analyze whether the past 2010 earthquake affected trust and trustworthiness in rural communities. Results show that trust levels are invariant between villages affected by the earthquake and villages not affected by this shock (control group). However, we find statistical evidence that trustworthiness has diminished in areas affected by the earthquake. Results are relevant for policy regarding aid and recovery of communities affected by these types of disasters.Trust games, natural disasters, trustworthiness, Community/Rural/Urban Development, International Development, C93, O13,

    ESTIMATED IMPACT OF NON-PRICE COORDINATION OF FED CATTLE PURCHASES ON MEAT PACKER PROCESSING COSTS

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    Stochastic simulation of daily slaughter level was used in conjunction with an estimated packing plant cost curve to assess potential reductions in processing costs due to improved vertical coordination between feedlots and packing plants. Results indicate that processing cost reductions of 1to1 to 5 per head may be possible. Savings result from ensuring a more stable processing volume that is near the plant's cost-minimizing level of production.cattle, cost curve, meat packing, vertical coordination, Industrial Organization, Livestock Production/Industries,

    The Sleep Condition Indicator: a clinical screening tool to evaluate insomnia disorder

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    Objective: Describe the development and psychometric validation of a brief scale (the Sleep Condition Indicator (SCI)) to evaluate insomnia disorder in everyday clinical practice.<p></p> Design: The SCI was evaluated across five study samples. Content validity, internal consistency and concurrent validity were investigated.<p></p> Participants: 30 941 individuals (71% female) completed the SCI along with other descriptive demographic and clinical information.<p></p> Setting: Data acquired on dedicated websites.<p></p> Results: The eight-item SCI (concerns about getting to sleep, remaining asleep, sleep quality, daytime personal functioning, daytime performance, duration of sleep problem, nights per week having a sleep problem and extent troubled by poor sleep) had robust internal consistency (α≥0.86) and showed convergent validity with the Pittsburgh Sleep Quality Index and Insomnia Severity Index. A two-item short-form (SCI-02: nights per week having a sleep problem, extent troubled by poor sleep), derived using linear regression modelling, correlated strongly with the SCI total score (r=0.90).<p></p> Conclusions: The SCI has potential as a clinical screening tool for appraising insomnia symptoms against Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria.<p></p&gt

    Innate Intracellular Antiviral Responses Restrict the Amplification of Defective Virus Genomes of Parainfluenza Virus 5.

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    During the replication of parainfluenza virus 5 (PIV5), copyback defective virus genomes (DVGs) are erroneously produced and are packaged into "infectious" virus particles. Copyback DVGs are the primary inducers of innate intracellular responses, including the interferon (IFN) response. While DVGs can interfere with the replication of nondefective (ND) virus genomes and activate the IFN-induction cascade before ND PIV5 can block the production of IFN, we demonstrate that the converse is also true, i.e., high levels of ND virus can block the ability of DVGs to activate the IFN-induction cascade. By following the replication and amplification of DVGs in A549 cells that are deficient in a variety of innate intracellular antiviral responses, we show that DVGs induce an uncharacterized IFN-independent innate response(s) that limits their replication. High-throughput sequencing was used to characterize the molecular structure of copyback DVGs. While there appears to be no sequence-specific break or rejoining points for the generation of copyback DVGs, our findings suggest there are region, size, and/or structural preferences selected for during for their amplification.IMPORTANCE Copyback defective virus genomes (DVGs) are powerful inducers of innate immune responses both in vitro and in vivo They impact the outcome of natural infections, may help drive virus-host coevolution, and promote virus persistence. Due to their potent interfering and immunostimulatory properties, DVGs may also be used therapeutically as antivirals and vaccine adjuvants. However, little is known of the host cell restrictions which limit their amplification. We show here that the generation of copyback DVGs readily occurs during parainfluenza virus 5 (PIV5) replication, but that their subsequent amplification is restricted by the induction of innate intracellular responses. Molecular characterization of PIV5 copyback DVGs suggests that while there are no genome sequence-specific breaks or rejoin points for the generation of copyback DVGs, genome region, size, and structural preferences are selected for during their evolution and amplification

    A QTL for osteoporosis detected in an F2 population derived from White Leghorn chicken lines divergently selected for bone index

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    Osteoporosis, resulting from progressive loss of structural bone during the period of egg-laying in hens, is associated with an increased susceptibility to bone breakage. To study the genetic basis of bone strength, an F cross was produced from lines of hens that had been divergently selected for bone index from a commercial pedigreed White Leghorn population. Quantitative trait loci (QTL) affecting the bone index and component traits of the index (tibiotarsal and humeral strength and keel radiographic density) were mapped using phenotypic data from 372 F individuals in 32 F families. Genotypes for 136 microsatellite markers in 27 linkage groups covering ∼80% of the genome were analysed for association with phenotypes using within-family regression analyses. There was one significant QTL on chromosome 1 for bone index and the component traits of tibiotarsal and humeral breaking strength. Additive effects for tibiotarsal breaking strength represented 34% of the trait standard deviation and 7.6% of the phenotypic variance of the trait. These QTL for bone quality in poultry are directly relevant to commercial populations

    Imaging analysis of LDEF craters

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    Two small craters in Al from the Long Duration Exposure Facility (LDEF) experiment tray A11E00F (no. 74, 119 micron diameter and no. 31, 158 micron diameter) were analyzed using Auger electron spectroscopy (AES), time-of-flight secondary ion mass spectroscopy (TOF-SIMS), low voltage scanning electron microscopy (LVSEM), and SEM energy dispersive spectroscopy (EDS). High resolution images and sensitive elemental and molecular analysis were obtained with this combined approach. The result of these analyses are presented

    A Third Pandemic is on the Horizon

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    The emergence of the novel SARS-CoV-2 virus and the resultant COVID-19 pandemic has brought the world to a standstill. In the United States, the morbidity and mortality associated with COVID-19 infection has disproportionately impacted Black, Indigenous and People of Color (BIPOC) communities, highlighting an underlying “second pandemic” perpetuated by the deeply-rooted health care inequities and social determinants of health. In this manuscript, we warn about a “Third Pandemic” on the horizon which could be driven by federal policies that fail to ensure equitable access to COVID-specific therapeutics for BIPOC communities, and the potential inequitable implementation of such policies that could further perpetuate disparities in health outcomes
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