Why humans build fires shaped the same way.
Ontology highlight
ABSTRACT:
SUBMITTER: Bejan A
PROVIDER: S-EPMC4459218 | biostudies-other | 2015
REPOSITORIES: biostudies-other
Similar Datasets
Project description:Developing interactive ways to teach about concepts such as complementation can be difficult. This approach, supported by learning data, uses blind cavefish as an example.
| S-EPMC3295817 | biostudies-literature
Project description:Human mtDNA shows striking regional variation, traditionally attributed to genetic drift. However, it is not easy to account for the fact that only two mtDNA lineages (M and N) left Africa to colonize Eurasia and that lineages A, C, D, and G show a 5-fold enrichment from central Asia to Siberia. As an alternative to drift, natural selection might have enriched for certain mtDNA lineages as people migrated north into colder climates. To test this hypothesis we analyzed 104 complete mtDNA sequences from all global regions and lineages. African mtDNA variation did not significantly deviate from the standard neutral model, but European, Asian, and Siberian plus Native American variations did. Analysis of amino acid substitution mutations (nonsynonymous, Ka) versus neutral mutations (synonymous, Ks) (kaks) for all 13 mtDNA protein-coding genes revealed that the ATP6 gene had the highest amino acid sequence variation of any human mtDNA gene, even though ATP6 is one of the more conserved mtDNA proteins. Comparison of the kaks ratios for each mtDNA gene from the tropical, temperate, and arctic zones revealed that ATP6 was highly variable in the mtDNAs from the arctic zone, cytochrome b was particularly variable in the temperate zone, and cytochrome oxidase I was notably more variable in the tropics. Moreover, multiple amino acid changes found in ATP6, cytochrome b, and cytochrome oxidase I appeared to be functionally significant. From these analyses we conclude that selection may have played a role in shaping human regional mtDNA variation and that one of the selective influences was climate.
| S-EPMC140917 | biostudies-literature
Project description:Humans often fail to identify a target because of nearby flankers. The nature and stages at which this crowding occurs are unclear, and whether crowding operates via a common mechanism across visual dimensions is unknown. Using a dual-estimation report (N = 42), we quantitatively assessed the processing of features alone and in conjunction with another feature both within and between dimensions. Under crowding, observers misreported colors and orientations (i.e., reported a flanker value instead of the target's value) but averaged the target's and flankers' spatial frequencies (SFs). Interestingly, whereas orientation and color errors were independent, orientation and SF errors were interdependent. These qualitative differences of errors across dimensions revealed a tight link between crowding and feature binding, which is contingent on the type of feature dimension. These results and a computational model suggest that crowding and misbinding are due to pooling across a joint coding of orientations and SFs but not of colors.
| S-EPMC6794901 | biostudies-literature
Project description:The emotional state can influence decision-making under ambiguity. Cognitive bias tests (CBT) proved to be a promising indicator of the affective valence of animals in a context of farm animal welfare. Although it is well-known that humans can influence the intensity of fear and reactions of animals, research on cognitive bias often focusses on housing and management conditions and neglects the role of humans on emotional states of animals. The present study aimed at investigating whether humans can modulate the emotional state of weaned piglets. Fifty-four piglets received a chronic experience with humans: gentle (GEN), rough (ROU) or minimal contact (MIN). Simultaneously, they were individually trained on a go/no-go task to discriminate a positive auditory cue, associated with food reward in a trough, from a negative one, associated with punishments (e.g. water spray). Independently of the treatment (P = 0.82), 59% of piglets completed the training. Successfully trained piglets were then subjected to CBT, including ambiguous cues in presence or absence of a human observer. As hypothesized, GEN piglets showed a positive judgement bias, as shown by their higher percentage of go responses following an ambiguous cue compared to ROU (P = 0.03) and MIN (P = 0.02) piglets, whereas ROU and MIN piglets did not differ (P > 0.10). The presence of an observer during CBT did not modulate the percentage of go responses following an ambiguous cue (P > 0.10). However, regardless of the treatment, piglets spent less time in contact with the trough following positive cues during CBT in which the observer was present than absent (P < 0.0001). This study originally demonstrates that the nature of a chronic experience with humans can induce a judgement bias indicating that the emotional state of farm animals such as piglets can be affected by the way humans interact with them.
| S-EPMC4526664 | biostudies-literature
Project description:There are mean differences in complex traits among global human populations. We hypothesize that part of the phenotypic differentiation is due to natural selection. To address this hypothesis, we assess the differentiation in allele frequencies of trait-associated SNPs among African, Eastern Asian, and European populations for ten complex traits using data of large sample size (up to ~405,000). We show that SNPs associated with height ([Formula: see text]), waist-to-hip ratio ([Formula: see text]), and schizophrenia ([Formula: see text]) are significantly more differentiated among populations than matched "control" SNPs, suggesting that these trait-associated SNPs have undergone natural selection. We further find that SNPs associated with height ([Formula: see text]) and schizophrenia ([Formula: see text]) show significantly higher variance in linkage disequilibrium (LD) scores across populations than control SNPs. Our results support the hypothesis that natural selection has shaped the genetic differentiation of complex traits, such as height and schizophrenia, among worldwide populations.
| S-EPMC5951811 | biostudies-literature
Project description:Rhesus monkeys are widely used as an animal model for human memory, including visual working memory (VWM). It is, however, unknown whether the same principles govern VWM in humans and rhesus monkeys. Here, we tested both species in nearly identical change-localization paradigms and formally compared the same set of models of VWM limitations. These models include the classic item-limit model and recent noise-based (resource) models, as well as hybrid models that combine a noise-based representation with an item limit. By varying the magnitude of the change in addition to the typical set size manipulation, we were able to show large differences in goodness of fit among the five models tested. In spite of quantitative performance differences between the species, we find that the variable-precision model--a noise-based model--best describes the behavior of both species. Adding an item limit to this model does not help to account for the data. Our results suggest evolutionary continuity of VWM across primates and help establish the rhesus monkey as a model system for studying the neural substrates of multiple-item VWM.
| S-EPMC5079709 | biostudies-literature
Project description:Providing remote psychotherapy using technology is a growing practice, especially since the outbreak of the COVID-19 pandemic. Even if in numerous studies video conferencing psychotherapy (VCP) was found to be clinically effective, some doubts continue to exist about how the psychotherapeutic alliance works in the online setting, and the characteristics of the empathic process are still poorly understood. This is an exploratory study aimed at analyzing the degree of empathy between the psychotherapist and client pair, and the degree of support perceived by the client who shall be referred to as the patient interchangeably in this study, comparing the sessions in person with those online, during the current pandemic, in order to discriminate the impact of empathy in the digital setting. The sample analyzed was composed of 23 patients with different severity of pathology engaged in online and in-person therapeutic sessions with five psychotherapists of different theoretical leanings. The scores of the support and empathy scale, obtained by both members of the psychotherapeutic couple in the two settings, were analyzed and compared. The test used belongs to an Italian adaptation of the Empathic Understanding (EU) of the Relationship Inventory. What emerged from comparing the scores was interesting: Unlike the psychotherapists, the patients perceived their therapists as significantly more empathic and supportive in the remote setting. These are rather important data, because the literature documents that client empathic perception measures represent a more accurate measure of the empathic relationship and, in general, can predict a good treatment outcome. Although these results need further investigation, they represent an important contribution in filling the scientific gap in the understanding of digital empathy. Also, this study provides new insights for future research on the characteristics and impact empathy has on the practice of remote psychotherapy.
| S-EPMC8490728 | biostudies-literature
Project description:Forest fires are a serious environmental hazard in southern Europe. Quantitative assessment of recent trends in fire statistics is important for assessing the possible shifts induced by climate and other environmental/socioeconomic changes in this area. Here we analyse recent fire trends in Portugal, Spain, southern France, Italy and Greece, building on a homogenized fire database integrating official fire statistics provided by several national/EU agencies. During the period 1985-2011, the total annual burned area (BA) displayed a general decreasing trend, with the exception of Portugal, where a heterogeneous signal was found. Considering all countries globally, we found that BA decreased by about 3020 km2 over the 27-year-long study period (i.e. about -66% of the mean historical value). These results are consistent with those obtained on longer time scales when data were available, also yielding predominantly negative trends in Spain and France (1974-2011) and a mixed trend in Portugal (1980-2011). Similar overall results were found for the annual number of fires (NF), which globally decreased by about 12600 in the study period (about -59%), except for Spain where, excluding the provinces along the Mediterranean coast, an upward trend was found for the longer period. We argue that the negative trends can be explained, at least in part, by an increased effort in fire management and prevention after the big fires of the 1980's, while positive trends may be related to recent socioeconomic transformations leading to more hazardous landscape configurations, as well as to the observed warming of recent decades. We stress the importance of fire data homogenization prior to analysis, in order to alleviate spurious effects associated with non-stationarities in the data due to temporal variations in fire detection efforts.
| S-EPMC4794223 | biostudies-literature
Project description:The neural mechanisms underlying human working memory are often inferred from studies using old-world monkeys. Humans use working memory to selectively memorize important information. We recently reported that monkeys do not seem to use selective memorization under experimental conditions that are common in monkey research, but less common in human research. Here we compare the performance of humans and monkeys under the same experimental conditions. Humans selectively remember important images whereas monkeys largely rely on recency information from nonselective memorization. Working memory studies in old-world monkeys must be interpreted cautiously when making inferences about the mechanisms underlying human working memory.
| S-EPMC5066608 | biostudies-literature
Project description:The extant literature indicates that threat enhances cognitive processing and physiological arousal. However, being largely based on fear-relevant processes, this model overlooks other adaptive but inhibitory mechanisms in alternative threat emotions such as disgust. Combining visual event-related potential (VERP) indices (P1 and P250/s) with a simple visual search task, we contrasted behavioral and neural responses to carefully controlled images of fear, disgust, or neutral emotion (as a baseline condition). Consistent with previous findings, fear augmented VERP amplitude and electrical current density in associate visual cortices, paralleled by facilitated object search. Conversely, disgust generated an opposite pattern of effects, reflected by reduced VERP potentials and diminished visual cortical current density along with slowed search time. These results demonstrated suppressed sensory perceptual and attentional processing of disgust information, akin to the central ecological function of disgust to minimize contact with contagious objects to avoid contamination and disease. Notably, the rapid emergence of discrimination between fear and disgust as early as 96 ms after stimulus emphasizes the efficiency of emotional classification not only between threat and nonthreat, but also within the threat domain itself. Finally, a positive correlation between anxiety and behavioral and neural divergence of fear and disgust further indicates that despite their convergence on the core affect of threat, disgust and fear instigate distinct response profiles, providing novel insights into the manifold and sometimes paradoxical symptomology in anxiety disorders.
| S-EPMC3077897 | biostudies-other