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131.
D. Caldwell Hahn Scott G. Summers Kenneth J. Genovese Haiqi He Michael H. Kogut 《Evolutionary biology》2013,40(4):554-561
Immune adaptations of obligate brood parasites attracted interest when three New World cowbird species (Passeriformes, Icteridae, genus Molothrus) proved unusually resistant to West Nile virus. We have used cowbirds as models to investigate the eco-immunological hypothesis that species in parasite-rich environments characteristically have enhanced immunity as a life history adaptation. As part of an ongoing program to understand the cowbird immune system, in this study we measured degranulation and oxidative burst, two fundamental responses of the innate immune system. Innate immunity provides non-specific, fast-acting defenses against a variety of invading pathogens, and we hypothesized that innate immunity experiences particularly strong selection in cowbirds, because their life history strategy exposes them to diverse novel and unpredictable parasites. We compared the relative effectiveness of degranulation and oxidative burst responses in two cowbird species and one related, non-parasitic species. Both innate immune defenses were significantly more functionally efficient in the two parasitic cowbird species than in the non-parasitic red-winged blackbird (Icteridae, Agelaius phoeniceus). Additionally, both immune defenses were more functionally efficient in the brown-headed cowbird (M. ater), an extreme host-generalist brood parasite, than in the bronzed cowbird (M. aeneus), a moderate host-specialist with lower exposure to other species and their parasites. Thus the relative effectiveness of these two innate immune responses corresponds to the diversity of parasites in the niche of each species and to their relative resistance to WNV. This study is the first use of these two specialized assays in a comparative immunology study of wild avian species. 相似文献
132.
133.
James B. Pease Matthew W. Hahn 《Evolution; international journal of organic evolution》2013,67(8):2376-2384
When speciation events occur in rapid succession, incomplete lineage sorting (ILS) can cause disagreement among individual gene trees. The probability that ILS affects a given locus is directly related to its effective population size (Ne), which in turn is proportional to the recombination rate if there is strong selection across the genome. Based on these expectations, we hypothesized that low‐recombination regions of the genome, as well as sex chromosomes and nonrecombining chromosomes, should exhibit lower levels of ILS. We tested this hypothesis in phylogenomic datasets from primates, the Drosophila melanogaster clade, and the Drosophila simulans clade. In all three cases, regions of the genome with low or no recombination showed significantly stronger support for the putative species tree, although results from the X chromosome differed among clades. Our results suggest that recurrent selection is acting in these low‐recombination regions, such that current levels of diversity also reflect past decreases in the effective population size at these same loci. The results also demonstrate how considering the genomic context of a gene tree can assist in more accurate determination of the true species phylogeny, especially in cases where a whole‐genome phylogeny appears to be an unresolvable polytomy. 相似文献
134.
European Wrynecks Jynx torquilla torquilla have generally been considered to be long‐distance Palaearctic–African migrants that spend the non‐breeding season in Sahelian Africa, where they have been reported regularly. Results from tracking individual birds showed that Wrynecks from two Central European populations migrated only relatively short distances to the Iberian Peninsula and northwestern Africa (c. 1500 km and 3000 km, respectively), compared with a minimum distance of about 4500 km to Sahelian Africa. Additionally, differences in wing lengths of populations from Central and Northern Europe support the idea of leap‐frog migration, populations from Northern Europe being long‐distance migrants with a non‐breeding distribution in Sahelian Africa. 相似文献
135.
136.
Kristian Soltesz Jin-Oh Hahn Tore Hägglund Guy A. Dumont J. Mark Ansermino 《Biomedical signal processing and control》2013,8(6):500-508
This paper proposes an individualized approach to closed-loop control of depth of hypnosis during propofol anesthesia. The novelty of the paper lies in the individualization of the controller at the end of the induction phase of anesthesia, based on a patient model identified from the dose–response relationship during induction of anesthesia. The proposed approach is shown to be superior to administration of propofol based on population-based infusion schemes tailored to individual patients. This approach has the potential to outperform fully adaptive approaches in regards to controller robustness against measurement variability due to surgical stimulation. To streamline controller synthesis, two output filters were introduced (inverting the Hill dose–response model and the linear time-invariant sensor model), which yield a close-to-linear representation of the system dynamics when used with a compartmental patient model. These filters are especially useful during the induction phase of anesthesia in which a nonlinear dose–response relationship complicates the design of an appropriate controller. The proposed approach was evaluated in simulation on pharmacokinetic and pharmacodynamic models of 44 patients identified from real clinical data. A model of the NeuroSense, a hypnotic depth monitor based on wavelet analysis of EEG, was also included. This monitor is similar to the well-known BIS, but has linear time-invariant dynamics and does not introduce a delay. The proposed scheme was compared with a population-based controller, i.e. a controller only utilizing models based on demographic covariates for its tuning. On average, the proposed approach offered 25% improvement in disturbance attenuation, measured as the integrated absolute error following a step disturbance. The corresponding standard deviation from the reference was also decreased by 25%. Results are discussed and possible directions of future work are proposed. 相似文献
137.
Min Kwon Joon-Yeop Lee Wang-Youn Won Jae-Woo Park Jung-Ah Min Changtae Hahn Xinyu Gu Ji-Hye Choi Dai-Jin Kim 《PloS one》2013,8(2)
Objective
The aim of this study was to develop a self-diagnostic scale that could distinguish smartphone addicts based on the Korean self-diagnostic program for Internet addiction (K-scale) and the smartphone''s own features. In addition, the reliability and validity of the smartphone addiction scale (SAS) was demonstrated.Methods
A total of 197 participants were selected from Nov. 2011 to Jan. 2012 to accomplish a set of questionnaires, including SAS, K-scale, modified Kimberly Young Internet addiction test (Y-scale), visual analogue scale (VAS), and substance dependence and abuse diagnosis of DSM-IV. There were 64 males and 133 females, with ages ranging from 18 to 53 years (M = 26.06; SD = 5.96). Factor analysis, internal-consistency test, t-test, ANOVA, and correlation analysis were conducted to verify the reliability and validity of SAS.Results
Based on the factor analysis results, the subscale “disturbance of reality testing” was removed, and six factors were left. The internal consistency and concurrent validity of SAS were verified (Cronbach''s alpha = 0.967). SAS and its subscales were significantly correlated with K-scale and Y-scale. The VAS of each factor also showed a significant correlation with each subscale. In addition, differences were found in the job (p<0.05), education (p<0.05), and self-reported smartphone addiction scores (p<0.001) in SAS.Conclusions
This study developed the first scale of the smartphone addiction aspect of the diagnostic manual. This scale was proven to be relatively reliable and valid. 相似文献138.
139.
Christian Montag Elisabeth Hahn Martin Reuter Frank M. Spinath Ken Davis Jaak Panksepp 《PloS one》2016,11(3)
The present study investigated for the first time the relative importance of genetics and environment on individual differences in primary emotionality as measured with the Affective Neuroscience Personality Scales (ANPS) by means of a twin-sibling study design. In N = 795 participants (n = 303 monozygotic twins, n = 172 dizygotic twins and n = 267 non-twin full siblings), moderate to strong influences of genetics on individual differences in these emotional systems are observed. Lowest heritability estimates are presented for the SEEKING system (33%) and highest for the PLAY system (69%). Further, multivariate genetic modeling was applied to the data showing that associations among the six ANPS scales were influences by both, a genetic as well as an environmental overlap between them. In sum, the study underlines the usefulness of the ANPS for biologically oriented personality psychology research. 相似文献
140.