Roembke T.C.,University of Iowa |
Roembke T.C.,DeLTA Center |
Wasserman E.A.,University of Iowa |
Wasserman E.A.,DeLTA Center |
And 2 more authors.
Journal of Experimental Psychology: General | Year: 2016
Adaptive behaviors are believed to be shaped by both positive (the strengthening of correct associations) and negative (the pruning of incorrect associations or the building of inhibitory associations) forms of associative learning. However, there has been little direct documentation of how these basic processes participate in the learning of rich associative networks that support cognitive behaviors like categorization. Although negative associative learning is an important component of theories of development, it is not clear whether it involves acquiring specific (experience-dependent) content or represents a more general aspect of (experience-expectant) development. The authors thus trained pigeons on a complex many-to-many learning paradigm previously established as an analog to human word learning. Pigeons learned to map 16 objects onto 16 distinct report tokens; the authors manipulated the amount of negative associative learning that could occur by restricting which tokens were available as incorrect options. In testing, accuracy was lower on trials with foils that had not been presented with a target than on trials with previously experienced foils. Moreover, when the correct token was withheld, pigeons preferred foils novel to the target object over previously experienced foils. A second experiment replicated these results and further found that these effects only emerged after some positive associations had been acquired. Findings indicate that the learning of rich associative networks does not depend solely on positive associative learning, but also on negative associative learning; this conclusion has important implications for basic learning theories in both animals and humans, as well as for theories of development. © 2016 American Psychological Association.
Mengistu A.,U.S. Department of Agriculture |
Bond J.,Southern Illinois University Carbondale |
Mian R.,Ohio State University |
Nelson R.,270 National Soybean Research Center |
And 2 more authors.
Crop Science | Year: 2011
Frogeye leaf spot (FLS) of soybean [Glycine max (L.) Merr.], caused by Cercospora sojina K. Hara, has been a problem in the southern United States for many years. Cultivars resistant to FLS have been developed for planting in this area, and resistance in many of these cultivars is conditioned by the Rcs3 allele at the Rcs3 locus, which provides immunity to all known races of the pathogen. Frogeye leaf spot has recently become a greater problem in the northern United States, and few C. sojina resistant cultivars and breeding lines adapted to this area have been identified. The objectives of this study were to (i) identify maturity group (MG) 00 to VII accessions resistant to C. sojina race 11 by field screening at multiple locations over years and (ii) determine if FLS resistance in these accessions is likely to be conditioned by the Rcs3 allele. A total of 522 accessions were evaluated for reaction to race 11 in field trials in Missouri and Illinois during 2006 and 2007, and 84 of these lines did not develop symptoms of FLS and were field screened for reaction to natural inoculum in Tennessee during 2008. Nine accessions of the 84 lines were susceptible. The remaining 75 were subsequently tested for the possible presence of Rcs3 using five molecular markers located within 2 cM of the gene. Of these 75 accessions, only PI 437726, PI 438302B, and PI 494851 had the Rcs3 haplotype of the cultivar Davis, the source of Rcs3. The soybean accessions predicted not to have the Rcs3 allele and with no FLS symptoms in field trials may also be useful in developing soybean cultivars with resistance to FLS. © Crop Science Society of America.
Straub C.M.,University of Utah |
Price R.R.,Intermountain Healthcare |
Matthews D.,University of Utah |
Handrahan D.L.,Statistical Data Center |
Sergelen D.,Delta Center
World Journal of Surgery | Year: 2011
Background: Although laparoscopic cholecystectomy was first introduced in Mongolia in 1994, the benefits of the laparoscopic approach have been largely unavailable to the majority of the population. The burden of gallbladder disease in Mongolia is significant. Despite the barriers to expanding laparoscopic surgery in Mongolia (lack of physical resources and adequate training opportunities, a difficult political situation, and an austere environment), the Health Sciences University of Mongolia (HSUM) began looking for ways to further the development of laparoscopy for the entire country, including the rural areas where half the population resides. Methods: Combined didactic and practical training courses lasting 2 weeks were developed collaboratively by a private nongovernmental organization and HSUM. The courses were taught at tertiary care centers in the capital city (Ulaanbaatar) and in a smaller, rural city (Erdenet), the regional northern referral center. Demographic data, preoperative diagnosis, ultrasound and operative findings, operative times, length of hospital stay, and intraoperative and postoperative complication rates were compared from 2007-2008 from hospitals in Ulaanbaatar and Erdenet. Results: A total of 36 surgeons participated in the training classes, and a total of 410 laparoscopic cholecystectomies were performed. Ultrasound was used as a diagnostic tool in all cases. There was no significant difference in intraoperative or postoperative complications between hospitals in the capital, where the procedures were performed by skilled laparoscopic surgeons, and in Erdenet, where the training courses first introduced laparoscopic cholecystectomy. Neither were there differences in complication rates between cases during the teaching and nonteaching periods. Conclusions: Laparoscopic cholecystectomy can be expanded safely to the regional diagnostic referral centers in rural Mongolia through short-term training courses as a method to markedly improve access and outcomes for the 50% of the country previously denied the benefits of minimally invasive surgery. © 2011 Société Internationale de Chirurgie.
Owen A.J.,University of Iowa |
Owen A.J.,DeLTA Center
Journal of Child Language | Year: 2011
Children with SLI have difficulty with tense and agreement morphology. This study examined the proficiency of these children and their typically developing peers with the coordination of tense and aspect markers in two-clause sentences. Scenarios designed to elicit past tense were presented to five- to eight-year-old children with SLI (n=14) and their normally developing age- and MLU-matched peers (n=24) to examine the omission of tense markers in complex sentences (Owen, 2010). Responses with overt tense/aspect morphology in both clauses were recoded for how similar the use of tense and aspect was across the two clauses. Tense and aspect concordance was high across both sentence types, but aspect-only mismatches were more common than tense mismatches. The three groups of children did not differ from each other on any comparisons. Coordination of temporal information in sentences with more than one time marker does not appear to be especially difficult for these children. © 2010 Cambridge University Press.
Costafreda-Aumedes S.,University of Lleida |
Cardil A.,University of Lleida |
Molina D.M.,University of Lleida |
Daniel S.N.,Delta Center |
And 2 more authors.
IForest | Year: 2016
In Spain, the established fire control policy states that all fires must be controlled and put out as soon as possible. Though budgets have not restricted operations until recently, we still experience large fires and we often face multiple-fire situations. Furthermore, fire conditions are expected to worsen in the future and budgets are expected to drop. To optimize the deployment of firefighting resources, we must gain insights into the factors affecting how it is conducted. We analyzed the national data base of historical fire records in Spain for patterns of deployment of fire suppression resources for large fires. We used artificial neural networks to model the relationships between the daily fire load, fire duration, fire type, fire size and response time, and the personnel and terrestrial and aerial units deployed for each fire in the period 1998-2008. Most of the models highlighted the positive correlation of burned area and fire duration with the number of resources assigned to each fire and some highlighted the negative influence of daily fire load. We found evidence suggesting that firefighting resources in Spain may already be under duress in their compliance with Spain’s current full suppression policy. © SISEF.
Seelke A.M.H.,Delta Center |
Blumberg M.S.,Delta Center
Brain Research | Year: 2010
Until recently, organized and state-dependent neocortical activity in infant rats was thought to commence with the emergence of delta waves at postnatal day (P)11. This view is changing with the discovery of several forms of cortical activity that are detectible soon after birth, including spindle bursts (SBs) and slow activity transients (SATs). Here we provide further evidence of surprisingly rich cortical activity patterns during early development and document, in P5-P13 rats, the appearance, disappearance, and transient expression of three cortical events and oscillations. EEG activity in frontal, parietal, and occipital cortices was recorded in unanesthetized, head-fixed subjects using 16-channel laminar silicon electrodes and Ag-AgCl electrodes. In addition to SATs, we identified two novel forms of activity: cortical sharp potentials (CSPs) and gamma bursts (GBs). SBs were not observed in these areas. CSPs, defined as discrete, biphasic events with a duration of 250 ms, exhibited an inverted-U developmental trajectory with peak prevalence at P9. In contrast, GBs, defined as brief bursts of 40-Hz activity, increased steadily in prevalence and duration from P5 through P13. The prevalence of SATs decreased steadily across the ages tested here. Furthermore, both CSPs and GBs were more likely to occur during sleep than during wakefulness. Because SATs, CSPs, and GBs exhibit different developmental trajectories and rates of occurrence, and can occur independently of each other, they appear to be distinct patterns of neuronal activity. We hypothesize that these diverse patterns of neurophysiological activity reflect the instantaneous local structure and connectivity of the developing neocortex.