806 research outputs found
Premotor cortex in observing erroneous action: An fMRI study
The lateral premotor cortex (PMC) is involved during action observation in monkeys and humans, reflecting a matching process between observed actions and their corresponding motor schemata. In the present study, functional magnetic resonance imaging (fMRI) was used to investigate if paying attention to the two observable action components, objects and movements, modulates premotor activation during the observation of actions. Participants were asked to classify presented movies as showing correct actions, erroneous actions, or senseless movements. Erroneous actions were incorrect either with regard to employed objects, or to performed movements. The experiment yielded two major results: (1) The ventrolateral premotor cortex (vPMC) and the anterior part of the intraparietal sulcus (aIPS) are strongly activated during the observation of actions in humans. Premotor activation was dominantly located within Brodmann Area (BA) 6, and sometimes extended into BA 44. (2) The presentation of object errors and movements errors allowed to disentangle brain activations corresponding to the analysis of movements and objects in observed actions. Left premotor areas were more involved in the analysis of objects, whereas right premotor areas were dominant in the analysis of movements. It is suggested that the analysis of categorical information, like objects, and that of coordinate information, like movements, are pronounced in different hemispheres
Evolutionary biology of birds and their associated microbiota in the Madrean Archipelago sky islands
Sky islands are disjunct patches of montane forested habitat in a matrix of desert, grasslands, and scrub. I investigated intraspecific evolutionary biology of two bird species—the White‐breasted Nuthatch (Sitta carolinensis) and the Brown Creeper (Certhia americana)—in the Madrean Archipelago sky islands (Arizona, USA), a biodiversity and evolution hotspot. In addition, I explored patterns of codiversification of these two birds and their associated gut microbial communities. The two bird studies revealed different patterns of diversification within the sky islands. The White‐breasted Nuthatch exhibits a pattern of isolation by environment, where genetic differences among populations are related to environmental differences of those localities. In contrast, the Brown Creeper has a strong genetic break between northern and southern populations, with no evidence of gene flow between lineages. When I investigated codiversification of birds and their microbial communities, I found no relationship between host genetic diversity and microbial community alpha diversity, while genetic differentiation between birds was significantly related with beta diversity between microbial communities. This dissertation provides a first step in comparative evolutionary biology of Madrean Archipelago avian taxa, and adds to the knowledge of the factors shaping microbial community diversity in wild animals
Comparison of Target-Capture and Restriction-Site Associated DNA Sequencing for Phylogenomics: A Test in Cardinalid Tanagers (Aves, Genus: Piranga)
This is a pre-copyedited, author-produced version of an article accepted for publication in Systematic Biology following peer review. The version of record, Joseph D. Manthey, Luke C. Campillo, Kevin J. Burns, Robert G. Moyle; Comparison of Target-Capture and Restriction-Site Associated DNA Sequencing for Phylogenomics: A Test in Cardinalid Tanagers (Aves, Genus: Piranga), Systematic Biology, Volume 65, Issue 4, 1 July 2016, Pages 640–650, is available online at: ttps://doi.org/10.1093/sysbio/syw005.Restriction-site associated DNA sequencing (RAD-seq) and target capture of specific genomic regions, such as ultraconserved elements (UCEs), are emerging as two of the most popular methods for phylogenomics using reduced-representation genomic data sets. These two methods were designed to target different evolutionary timescales: RAD-seq was designed for population-genomic level questions and UCEs for deeper phylogenetics. The utility of both data sets to infer phylogenies across a variety of taxonomic levels has not been adequately compared within the same taxonomic system. Additionally, the effects of uninformative gene trees on species tree analyses (for target capture data) have not been explored. Here, we utilize RAD-seq and UCE data to infer a phylogeny of the bird genus Piranga. The group has a range of divergence dates (0.5–6 myr), contains 11 recognized species, and lacks a resolved phylogeny. We compared two species tree methods for the RAD-seq data and six species tree methods for the UCE data. Additionally, in the UCE data, we analyzed a complete matrix as well as data sets with only highly informative loci. A complete matrix of 189 UCE loci with 10 or more parsimony informative (PI) sites, and an approximately 80% complete matrix of 1128 PI single-nucleotide polymorphisms (SNPs) (from RAD-seq) yield the same fully resolved phylogeny of Piranga. We inferred non-monophyletic relationships of Pirangalutea individuals, with all other a priori species identified as monophyletic. Finally, we found that species tree analyses that included predominantly uninformative gene trees provided strong support for different topologies, with consistent phylogenetic results when limiting species tree analyses to highly informative loci or only using less informative loci with concatenation or methods meant for SNPs alone
Wireless recording of the calls of Rousettus aegyptiacus and their reproduction using electrostatic transducers
Bats are capable of imaging their surroundings in great detail using echolocation. To apply similar methods to human engineering systems requires the capability to measure and recreate the signals used, and to understand the processing applied to returning echoes. In this work, the emitted and reflected echolocation signals of Rousettus aegyptiacus are recorded while the bat is in flight, using a wireless sensor mounted on the bat. The sensor is designed to replicate the acoustic gain control which bats are known to use, applying a gain to returning echoes that is dependent on the incurred time delay. Employing this technique allows emitted and reflected echolocation calls, which have a wide dynamic range, to be recorded. The recorded echoes demonstrate the complexity of environment reconstruction using echolocation. The sensor is also used to make accurate recordings of the emitted calls, and these calls are recreated in the laboratory using custom-built wideband electrostatic transducers, allied with a spectral equalization technique. This technique is further demonstrated by recreating multi-harmonic bioinspired FM chirps. The ability to record and accurately synthesize echolocation calls enables the exploitation of biological signals in human engineering systems for sonar, materials characterization and imaging
Multiple sequence alignment based on set covers
We introduce a new heuristic for the multiple alignment of a set of
sequences. The heuristic is based on a set cover of the residue alphabet of the
sequences, and also on the determination of a significant set of blocks
comprising subsequences of the sequences to be aligned. These blocks are
obtained with the aid of a new data structure, called a suffix-set tree, which
is constructed from the input sequences with the guidance of the
residue-alphabet set cover and generalizes the well-known suffix tree of the
sequence set. We provide performance results on selected BAliBASE amino-acid
sequences and compare them with those yielded by some prominent approaches
Classifying national drinking patterns in Europe between 2000 and 2019: A clustering approach using comparable exposure data
Background and aims: Previously identified national drinking patterns in Europe lack comparability and might be no longer be valid due to changes in economic conditions and policy frameworks. We aimed to identify the most recent alcohol drinking patterns in Europe based on comparable alcohol exposure indicators using a data-driven approach, as well as identifying temporal changes and establishing empirical links between these patterns and indicators of alcohol-related harm. Design: Data from the World Health Organization's monitoring system on alcohol exposure indicators were used. Repeated cross-sectional hierarchical cluster analyses were applied. Differences in alcohol-attributable harm between clusters of countries were analyzed via linear regression. Setting: European Union countries, plus Iceland, Norway and Ukraine, for 2000, 2010, 2015 and 2019. Participants/Cases: Observations consisted of annual country data, at four different time points for alcohol exposure. Harm indicators were only included for 2019. Measurements: Alcohol exposure indicators included alcohol per capita consumption (APC), beverage-specific consumption and prevalence of drinking status indicators (lifetime abstainers, current drinkers, former drinkers and heavy episodic drinking). Alcohol-attributable harm was measured using age-standardized alcohol-attributable Disability-Adjusted Life Years (DALYs) lost and deaths per 100 000 people. Findings: The same six clusters were identified in 2019, 2015 and 2010, mainly characterized by type of alcoholic beverage and prevalence drinking status indicators, with geographical interpretation. Two-thirds of the countries remained in the same cluster over time, with one additional cluster identified in 2000, characterized by low APC. The most recent drinking patterns were shown to be significantly associated with alcohol-attributable deaths and DALY rates. Compared with wine-drinking countries, the mortality rate per 100 000 people was significantly higher in Eastern Europe with high spirits and ‘other’ beverage consumption [(Formula presented.) = 90, 95% confidence interval (CI) = 55–126], and in Eastern Europe with high lifetime abstainers and high spirits consumption ((Formula presented.) = 42, 95% CI = 4–78). Conclusions: European drinking patterns appear to be clustered by level of beverage-specific consumption, with heavy episodic drinkers, current drinkers and lifetime abstainers being distinguishing factors between clusters. Despite the overall stability of the clusters over time, some countries shifted between drinking patterns from 2000 to 2019. Overall, patterns of drinking in the European Union seem to be stable and partly determined by geographical proximity. © 2024 World Health Organization; licensed by Society for the Study of Addiction. Addiction published by John Wiley & Sons Ltd on behalf of Society for the Study of Addiction.We thank Alexandra Fleischmann, Ilinca Radu, Dag Rekve and Vladimir Poznyak for establishing and maintaining the WHO global monitoring framework for alcohol and health and the regular updates of the Global Information System on Alcohol and Health; the data analyzed as part of this contribution were collected within this monitoring framework. We also like to express our gratitude to all nominated focal points from Member States, who have filled out the surveys and provided the needed data, as well as to Sergei Bychkov and Sumudu Kasturiarachchi for their overall support with the coordination of data collection and validation procedures in the WHO/Europe. The research leading to these results or outcomes has received funding from the EU4Health under contribution agreement no. SANTE/2022/SI2.883729 (Addressing alcohol harm—capacity building, raising awareness and implementation of best practices in the Union). Its contents are the sole responsibility of the authors and do not necessarily reflect the views of the European Commission. J.R. and K.D.S. were in part supported by a contract by the WHO from the WHO/PAHO Collaboration Centre. J.R. was supported by the Canadian Institutes of Health Research (CIHR FRN 477887)
Improving alcohol health literacy and reducing alcohol consumption: recommendations for Germany
Background: Although the detrimental health effects of alcohol are well established, consumption levels are high in many high-income countries such as Germany. Improving alcohol health literacy presents an integrated approach to alcohol prevention and an important complement to alcohol policy. Our aim was to identify and prioritize measures to enhance alcohol health literacy and hence to reduce alcohol consumption, using Germany as an example.Methods: A series of recommendations for improving alcohol health literacy were derived from a review of the literature and subsequently rated by five experts. Recommendations were rated according to their likely impact on enhancing (a) alcohol health literacy and (b) reducing alcohol consumption. Inter-rater agreement was assessed using a two-way intra-class correlation coefficient (ICC).Results: Eleven recommendations were established for three areas of action: (1) education and information, (2) health care system, and (3) alcohol control policy. Education and information measures were rated high to increase alcohol health literacy but low to their impact on alcohol consumption, while this pattern was reversed for alcohol control policies. The ratings showed good agreement (ICC: 0.85-0.88).Conclusions: Improving alcohol health literacy and reducing alcohol consumption should be considered complementary and become part of a comprehensive alcohol strategy to curb the health, social, and economic burden of alcohol
A genome-wide assessment of stages of elevational parapatry in Bornean passerine birds reveals no introgression: implications for processes and patterns of speciation
Topographically complex regions often contain the close juxtaposition of closely related species along elevational gradients. The evolutionary causes of these elevational replacements, and thus the origin and maintenance of a large portion of species diversity along elevational gradients, are usually unclear because ecological differentiation along a gradient or secondary contact following allopatric diversification can produce the same pattern. We used reduced representation genomic sequencing to assess genetic relationships and gene flow between three parapatric pairs of closely related songbird taxa (Arachnothera spiderhunters, Chloropsis leafbirds, and Enicurus forktails) along an elevational gradient in Borneo. Each taxon pair presents a different elevational range distribution across the island, yet results were uniform: little or no gene flow was detected in any pairwise comparisons. These results are congruent with an allopatric “species-pump” model for generation of species diversity and elevational parapatry of congeners on Borneo, rather than in situ generation of species by “ecological speciation” along an elevational gradient
Generalized Totalizer Encoding for Pseudo-Boolean Constraints
Pseudo-Boolean constraints, also known as 0-1 Integer Linear Constraints, are
used to model many real-world problems. A common approach to solve these
constraints is to encode them into a SAT formula. The runtime of the SAT solver
on such formula is sensitive to the manner in which the given pseudo-Boolean
constraints are encoded. In this paper, we propose generalized Totalizer
encoding (GTE), which is an arc-consistency preserving extension of the
Totalizer encoding to pseudo-Boolean constraints. Unlike some other encodings,
the number of auxiliary variables required for GTE does not depend on the
magnitudes of the coefficients. Instead, it depends on the number of distinct
combinations of these coefficients. We show the superiority of GTE with respect
to other encodings when large pseudo-Boolean constraints have low number of
distinct coefficients. Our experimental results also show that GTE remains
competitive even when the pseudo-Boolean constraints do not have this
characteristic.Comment: 10 pages, 2 figures, 2 tables. To be published in 21st International
Conference on Principles and Practice of Constraint Programming 201
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