Memory modeling of counterfactual generation.

We use a computational model of memory search to study how people generate counterfactual outcomes in response to an established target outcome. Hierarchical Bayesian model fitting to data from six experiments reveals that counterfactual outcomes that are perceived as more desirable and more likely to occur are also more likely to come to mind and are generated earlier than other outcomes. Additionally, core memory mechanisms such as semantic clustering and word frequency biases have a strong influence on retrieval dynamics in counterfactual thinking. Finally, we find that the set of counterfactuals that come to mind can be manipulated by modifying the total number of counterfactuals that participants are prompted to generate, and our model can predict these effects. Overall, our findings demonstrate how computational memory search models can be integrated with current theories of counterfactual thinking to provide novel insights into the process of generating counterfactual thoughts. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Limitations to optimal search in naturalistic active learning.

Optimality in active learning is under intense debate in numerous disciplines. We introduce a new empirical paradigm for studying naturalistic active learning, as well as new computational tools for jointly modeling algorithmic and rational theories of information search. Participants in our task can ask questions and learn about hundreds of everyday items but must retrieve queried items from memory. To maximize information gain, participants need to retrieve sequences of dissimilar items. In eight experiments (N = 795), we find that participants are unable to do this. Instead, associative memory mechanisms lead to the successive retrieval of similar items, an established memory effect known as semantic congruence. The extent of semantic congruence (and thus suboptimality in question asking) is unaffected by task instructions and incentives, though participants can identify efficient query sequences when given a choice between query sequences. Overall, our results indicate that participants can distinguish between optimal and suboptimal search if explicitly asked to do so, but have difficulty implementing optimal search from memory. We conclude that associative memory processes may place critical restrictions on people's ability to ask good questions in naturalistic active learning tasks. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Tracing Organophosphate Ester Pollutants in Hadal Trenches─Distribution, Possible Origins, and Transport Mechanisms.

Unraveling the mysterious pathways of pollutants to the deepest oceanic realms holds critical importance for assessing the integrity of remote marine ecosystems. This study tracks the transport of pollutants into the depths of the oceans, a key step in protecting the sanctity of these least explored ecosystems. By analyzing hadal trench samples from the Mariana, Mussau, and New Britain trenches, we found the widespread distribution of organophosphate ester (OPE) flame retardants but a complex transport pattern for the OPE in these regions. In the Mariana Trench seawater column, OPE concentrations range between 17.4 and 102 ng L-1, with peaks at depths of 500 and 4000 m, which may be linked to Equatorial Undercurrent and topographic Rossby waves, respectively. Sediments, particularly in Mariana (422 ng g-1 dw), showed high OPE affinity, likely due to organic matter serving as a transport medium, influenced by "solvent switching", "solvent depletion", and "filtering processes". Amphipods in the three trenches had consistent OPE levels (29.1-215 ng g-1 lipid weight), independent of the sediment pollution patterns. The OPEs in these amphipods appeared more linked to surface-dwelling organisms, suggesting the influence of "solvent depletion". This study highlights the need for an improved understanding of deep-sea pollutant sources and transport, urging the establishment of protective measures for these remote marine habitats.

Chromosome-level genome assembly of hadal snailfish reveals mechanisms of deep-sea adaptation in vertebrates.

As the deepest vertebrate in the ocean, the hadal snailfish (Pseudoliparis swirei), which lives at a depth of 6,000-8,000 m, is a representative case for studying adaptation to extreme environments. Despite some preliminary studies on this species in recent years, including their loss of pigmentation, visual and skeletal calcification genes, and the role of trimethylamine N-oxide in adaptation to high-hydrostatic pressure, it is still unknown how they evolved and why they are among the few vertebrate species that have successfully adapted to the deep-sea environment. Using genomic data from different trenches, we found that the hadal snailfish may have entered and fully adapted to such extreme environments only in the last few million years. Meanwhile, phylogenetic relationships show that they spread into different trenches in the Pacific Ocean within a million years. Comparative genomic analysis has also revealed that the genes associated with perception, circadian rhythms, and metabolism have been extensively modified in the hadal snailfish to adapt to its unique environment. More importantly, the tandem duplication of a gene encoding ferritin significantly increased their tolerance to reactive oxygen species, which may be one of the important factors in their adaptation to high-hydrostatic pressure.

Metagenomic 16S rDNA reads of in situ preserved samples revealed microbial communities in the Yongle blue hole.

Our knowledge on biogeochemistry and microbial ecology of marine blue holes is limited due to challenges in collecting multilayered water column and oxycline zones. In this study, we collected samples from 16 water layers in Yongle blue hole (YBH) located in the South China Sea using the in situ microbial filtration and fixation (ISMIFF) apparatus. The microbial communities based on 16S rRNA metagenomic reads for the ISMIFF samples showed high microbial diversity and consistency among samples with similar dissolved oxygen levels. At the same depth of the anoxic layer, the ISMIFF samples were dominated by sulfate-reducing bacteria from Desulfatiglandales (17.96%). The sulfide concentration is the most significant factor that drives the division of microbial communities in YBH, which might support the prevalence of sulfate-reducing microorganisms in the anoxic layers. Our results are different from the microbial community structures of a Niskin sample of this study and the reported samples collected in 2017, in which a high relative abundance of Alteromonadales (26.59%) and Thiomicrospirales (38.13%), and Arcobacteraceae (11.74%) was identified. We therefore demonstrate a new profile of microbial communities in YBH probably due to the effect of sampling and molecular biological methods, which provides new possibilities for further understanding of the material circulation mechanism of blue holes and expanding anoxic marine water zones under global warming.

Genomic evidence for the first symbiotic Deferribacterota, a novel gut symbiont from the deep-sea hydrothermal vent shrimp Rimicaris kairei.

The genus Rimicaris is the dominant organism living in hydrothermal vents. However, little research has been done on the functions of their intestinal flora. Here, we investigated the potential functions of Deferribacterota, which is dominant in the intestine of Rimicaris kairei from the Central Indian Ridge. In total, six metagenome-assembled genomes (MAGs) of Deferribacterota were obtained using the metagenomic approach. The six Deferribacterota MAGs (Def-MAGs) were clustered into a new branch in the phylogenetic tree. The six Def-MAGs were further classified into three species, including one new order and two new genera, based on the results of phylogenetic analysis, relative evolutionary divergence (RED), average nucleotide identity (ANI), average amino acid identity (AAI) and DNA-DNA hybridization (DDH) values. The results of the energy metabolism study showed that these bacteria can use a variety of carbon sources, such as glycogen, sucrose, salicin, arbutin, glucose, cellobiose, and maltose. These bacteria have a type II secretion system and effector proteins that can transport some intracellular toxins to the extracellular compartment and a type V CRISPR-Cas system that can defend against various invasions. In addition, cofactors such as biotin, riboflavin, flavin mononucleotide (FMN), and flavin adenine dinucleotide (FAD) synthesized by R. kairei gut Deferribacterota may also assist their host in surviving under extreme conditions. Taken together, the potential function of Deferribacterota in the hydrothermal R. kairei gut suggests its long-term coevolution with the host.

First evidence and potential sources of novel brominated flame retardants and BDE 209 in the deepest ocean.

Organic anthropogenic pollutants reach even the deepest parts of the oceans, i.e., the hadal trenches. We here presented the concentrations, influencing factors, and potential sources of polybrominated diphenyl ethers (PBDEs) and novel brominated flame retardants (NBFRs) in hadal sediments and amphipods from the Mariana, Mussau and New Britain trenches. Results showed that BDE 209 was the dominant PBDEs congener and DBDPE was the dominant NBFRs. No significant correlation was found between TOC contents and PBDEs or NBFRs levels in sediment. Lipid content and body length were the potential important factors affecting variation in pollutant concentrations in the carapace & muscle of amphipods, while the pollution levels of viscera were mainly affected by the sex and lipid content. PBDEs and NBFRs might reach trench surface seawater through long-range atmospheric transport and oceans currents but with little contribution from the Great Pacific Garbage Patch. Determination of carbon and nitrogen isotopes indicated that the pollutants were transported and accumulated in amphipods and sediment via different pathways. PBDEs and NBFRs in the hadal sediments were generally transported via the settling of sediment particles of either marine or terrigenous origin whereas in amphipods they accumulated via feeding on animal carrion through the food web. This is the first study reporting on BDE 209 and NBFR contaminations in hadal settings and provide new insight on influencing factors and sources of PBDEs and NBFRs in the deepest oceans.

Information acquisition and decision strategies in intertemporal choice.

Intertemporal decision models describe choices between outcomes with different delays. While these models mainly focus on predicting choices, they make implicit assumptions about how people acquire and process information. A link between information processing and choice model predictions is necessary for a complete mechanistic account of decision making. We establish this link by fitting 18 intertemporal choice models to experimental datasets with both choice and information acquisition data. First, we show that choice models have highly correlated fits: people that behave according to one model also behave according to other models that make similar information processing assumptions. Second, we develop and fit an attention model to information acquisition data. Critically, the attention model parameters predict which type of intertemporal choice models best describes a participant's choices. Overall, our results relate attentional processes to models of intertemporal choice, providing a stepping stone towards a complete mechanistic account of intertemporal decision making.

Complex economic decisions from simple neurocognitive processes: the role of interactive attention.

Neurocognitive theories of value-based choice propose that people additively accumulate choice attributes when making decisions. These theories cannot explain the emergence of complex multiplicative preferences such as those assumed by prospect theory and other economic models. We investigate an interactive attention mechanism, according to which attention to attributes (like payoffs) depends on other attributes (like probabilities) attended to previously. We formalize this mechanism using a Markov attention model combined with an accumulator decision process, and test our model on eye-tracking and mouse-tracking data in risky choice. Our tests show that interactive attention is necessary to make good choices, that most participants display interactive attention and that allowing for interactive attention in accumulation-based decision models improves their predictions. By equipping established decision models with sophisticated attentional dynamics, we extend these models to describe complex economic choice, and in the process, we unify two prominent theoretical approaches to studying value-based decision making.

Genome-centric view of the microbiome in a new deep-sea glass sponge species Bathydorus sp.

Sponges are widely distributed in the global ocean and harbor diverse symbiotic microbes with mutualistic relationships. However, sponge symbionts in the deep sea remain poorly studied at the genome level. Here, we report a new glass sponge species of the genus Bathydorus and provide a genome-centric view of its microbiome. We obtained 14 high-quality prokaryotic metagenome-assembled genomes (MAGs) affiliated with the phyla Nitrososphaerota, Pseudomonadota, Nitrospirota, Bdellovibrionota, SAR324, Bacteroidota, and Patescibacteria. In total, 13 of these MAGs probably represent new species, suggesting the high novelty of the deep-sea glass sponge microbiome. An ammonia-oxidizing Nitrososphaerota MAG B01, which accounted for up to 70% of the metagenome reads, dominated the sponge microbiomes. The B01 genome had a highly complex CRISPR array, which likely represents an advantageous evolution toward a symbiotic lifestyle and forceful ability to defend against phages. A sulfur-oxidizing Gammaproteobacteria species was the second most dominant symbiont, and a nitrite-oxidizing Nitrospirota species could also be detected, but with lower relative abundance. Bdellovibrio species represented by two MAGs, B11 and B12, were first reported as potential predatory symbionts in deep-sea glass sponges and have undergone dramatic genome reduction. Comprehensive functional analysis indicated that most of the sponge symbionts encoded CRISPR-Cas systems and eukaryotic-like proteins for symbiotic interactions with the host. Metabolic reconstruction further illustrated their essential roles in carbon, nitrogen, and sulfur cycles. In addition, diverse putative phages were identified from the sponge metagenomes. Our study expands the knowledge of microbial diversity, evolutionary adaption, and metabolic complementarity in deep-sea glass sponges.

Pseudo-chromosome-length genome assembly for a deep-sea eel Ilyophis brunneus sheds light on the deep-sea adaptation.

High hydrostatic pressure, low temperature, and scarce food supply are the major factors that limit the survival of vertebrates in extreme deep-sea environments. Here, we constructed a high-quality genome of the deep-sea Muddy arrowtooth eel (MAE, Ilyophis brunneus, captured below a depth of 3,500 m) by using Illumina, PacBio, and Hi-C sequencing. We compare it against those of shallow-water eel and other outgroups to explore the genetic basis that underlies the adaptive evolution to deep-sea biomes. The MAE genome was estimated to be 1.47 Gb and assembled into 14 pseudo-chromosomes. Phylogenetic analyses indicated that MAE diverged from its closely related shallow-sea species, European eel, ∼111.9 Mya and experienced a rapid evolution. The genome evolutionary analyses primarily revealed the following: (i) under high hydrostatic pressure, the positively selected gene TUBGCP3 and the expanded family MLC1 may improve the cytoskeleton stability; ACOX1 may enhance the fluidity of cell membrane and maintain transport activity; the expansion of ABCC12 gene family may enhance the integrity of DNA; (ii) positively selected HARS likely maintain the transcription ability at low temperatures; and (iii) energy metabolism under a food-limited environment may be increased by expanded and positively selected genes in AMPK and mTOR signaling pathways.

Comparative Analysis of the Mitochondrial Genome of Galatheanthemum sp. MT-2020 (Actiniaria Galatheanthemidae) From a Depth of 9,462 m at the Mariana Trench.

The hadal zone, which represents the deepest marine habitat on Earth (6,000-11,000 m), is a harsh environment mainly characterized by extremely high hydrostatic pressure, and this habitat is believed to have a high degree of endemism. The deep-sea anemone family Galatheanthemidae comprises two valid species exclusively from the hadal; however, no other information about this family is currently available. In the present study, a sea anemone was collected from a depth of 9,462 m at the Mariana Trench and was defined as Galatheanthemum sp. MT-2020 (Actiniaria Galatheanthemidae). The mitochondrial genome of Galatheanthemum sp. MT-2020 was circular, was 16,633 bp in length, and contained two ribosomal RNA genes, 13 protein-coding genes and two transfer RNA genes. The order of the genes of Galatheanthemum sp. MT-2020 was identical to that of the majority of the species of the order Actiniaria. The value of the AT-skew was the lowest in the whole mitochondrial genome, with a positive GC skew value for the atp8 gene, while other species, except Antholoba achates, had the negative values of the GC skew. Galatheanthemum sp. MT-2020 was clustered with another abyssal species, Paraphelliactis xishaensis, in the phylogenetic tree, and these species diverged in the early Jurassic approximately 200 Mya from the shallow-sea species. The usage ratio of valine, which is one of the five amino acids with the strongest barophilic properties, in the mitochondrial genomes of the two abyssal species was significantly higher than that in other species with habitats above the depth of 3,000 m. The ω (dN/dS) ratio of the genomes was 2.45-fold higher than that of the shallow-sea species, indicating a slower evolutionary rate. Overall, the present study is the first to provide a complete mitogenome of sea anemones from the hadal and reveal some characteristics that may be associated with adaptation to an extreme environment.

Cerebellum anatomy predicts individual risk-taking behavior and risk tolerance.

Human risk tolerance is highly idiosyncratic and individuals often show distinctive preferences when faced with similar risky situations. However, the neural underpinnings of individual differences in risk-taking remain unclear. Here we combined structural and perfusion MRI and examined the associations between brain anatomy and individual risk-taking behavior/risk tolerance in a sample of 115 healthy participants during the Balloon Analogue Risk Task, a well-established sequential risky decision paradigm. Both whole brain and region-of-interest analyses showed that the left cerebellum gray matter volume (GMV) has a strong association with individual risk-taking behavior and risk tolerance, outperforming the previously reported associations with the amygdala and right posterior parietal cortex (PPC) GMV. Left cerebellum GMV also accounted for risk tolerance and risk-taking behavior changes with aging. However, regional cerebral blood flow (CBF) provided no additional predictive power. These findings suggest a novel cerebellar anatomical contribution to individual differences in risk tolerance. Further studies are necessary to elucidate the underestimated important role of cerebellum in risk-taking.

Carbon metabolism and adaptation of hyperalkaliphilic microbes in serpentinizing spring of Manleluag, the Philippines.

Reduced substrates produced by the serpentinization reaction under hydration of olivine may have fuelled biological processes on early Earth. To understand the adaptive strategies and carbon metabolism of the microbes in the serpentinizing ecosystems, we reconstructed 18 draft genomes representing dominant species of Omnitrophicaeota, Gammaproteobacteria and Methanobacteria from the Manleluag serpentinizing spring in Zambales, Philippines (hyperalkaline and rich in methane and hydrogen). Phylogenomics revealed that two genomes were affiliated with a candidate phylum NPL-UPA2 and the references of all our genomes were derived from ground waters, hot springs and the deep biosphere. C1 metabolism appears to be widespread as most of the genomes code for methanogenesis, CO oxidation and CO2 fixation. However, likely due to the low CO2 concentration and election acceptors, the biomass in the spring was extremely low (<103 cell/ml). Various Na+ and K+ transporters and Na+ -driving ATPases appear to be encoded by these genomes, suggesting that nutrient acquisition, bioenergetics and normal cytoplasmic pH were dependent on Na+ and K+ pumps. Our results advance our understanding of the metabolic potentials and bioenergetics of serpentinizing springs and provide a framework of the ecology of early Earth.

Do women's natural hormonal fluctuations modulate prosociality? A within-subject analysis.

Prosocial behavior is central to functional societies. While studies have shown that the administration of exogenous hormones modulates prosocial propensities, it remains unclear whether natural hormonal fluctuations track women's prosocial behavior. In this study, we investigated the relationships between women's natural salivary steroid hormone levels (estradiol, progesterone, and testosterone) and their prosociality in a variety of contexts, as measured by three behavioral tasks (Charitable Donation, Social Value Orientation, and Social Discounting tasks) and one self-reported questionnaire (the Prosocial Tendencies Measure). Participants completed five weekly laboratory tests to obtain within-subject hormonal fluctuation data and prosociality measurements. In a pre-registered analysis, we found little evidence supporting the hypotheses that women's prosociality tracked natural changes in salivary estradiol, progesterone, estradiol-to-progesterone ratio, or testosterone. Our results demonstrate the importance of performing within-subject analyses when examining the relationships between hormonal levels and social behavior.

An ontology of decision models.

Decision models are essential theoretical tools in the study of choice behavior, but there is little consensus about the best model for describing choice, with different fields and different research programs favoring their own idiosyncratic sets of models. Even within a given field, decision models are seldom studied alongside each other, and insights obtained using 1 model are not typically generalized to others. We present the results of a large-scale computational analysis that uses landscaping techniques to generate a representational structure for describing decision models. Our analysis includes 89 prominent models of risky and intertemporal choice, and results in an ontology of decision models, interpretable in terms of model spaces, clusters, hierarchies, and graphs. We use this ontology to measure the properties of individual models and quantify the relationships between different models. Our results show how decades of quantitative research on human choice behavior can be synthesized within a single representational framework. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Characteristics of Two Crustins from Alvinocaris longirostris in Hydrothermal Vents.

Crustins are widely distributed among different crustacean groups. They are characterized by a whey acidic protein (WAP) domain, and most examined Crustins show activity against Gram-positive bacteria. This study reports two Crustins, Al-crus 3 and Al-crus 7, from hydrothermal vent shrimp, Alvinocaris longirostris. Al-crus 3 and Al-crus 7 belong to Crustin Type IIa, with a similarity of about 51% at amino acid level. Antibacterial assays showed that Al-crus 3 mainly displayed activity against Gram-positive bacteria with MIC50 values of 10-25 µM. However, Al-crus 7 not only displayed activity against Gram-positive bacteria but also against Gram-negative bacteria Imipenem-resistant Acinetobacter baumannii, in a sensitive manner. Notably, in the effective antibacterial spectrum, Methicillin-sensitive Staphylococcus aureus, Escherichia coli (ESBLs) and Imipenem-resistant A. baumannii were drug-resistant pathogens. Narrowing down the sequence to the WAP domain, Al-crusWAP 3 and Al-crusWAP 7 demonstrated antibacterial activities but were weak. Additionally, the effects on bacteria did not significantly change after they were maintained at room temperature for 48 h. This indicated that Al-crus 3 and Al-crus 7 were relatively stable and convenient for transportation. Altogether, this study reported two new Crustins with specific characteristics. In particular, Al-crus 7 inhibited Gram-negative imipenem-resistant A. baumannii.

Geology, environment, and life in the deepest part of the world's oceans.

The hadal zone, mostly comprising of deep trenches and constituting of the deepest part of the world's oceans, represents the least explored habitat but one of the last frontiers on our planet. The present scientific understanding of the hadal environment is still relatively rudimentary, particularly in comparison with that of shallower marine environments. In the last 30 years, continuous efforts have been launched in deepening our knowledge regarding the ecology of the hadal trench. However, the geological and environmental processes that potentially affect the sedimentary, geochemical and biological processes in hadal trenches have received less attention. Here, we review recent advances in the geology, biology, and environment of hadal trenches and offer a perspective of the hadal science involved therein. For the first time, we release high-definition images taken by a new full-ocean-depth manned submersible Fendouzhe that reveal novel species with an unexpectedly high density, outcrops of mantle and basaltic rocks, and anthropogenic pollutants at the deepest point of the world's ocean. We advocate that the hydration of the hadal lithosphere is a driving force that influences a variety of sedimentary, geochemical, and biological processes in the hadal trench. Hadal lithosphere might host the Earth's deepest subsurface microbial ecosystem. Future research, combined with technological advances and international cooperation, should focus on establishing the intrinsic linkage of the geology, biology, and environment of the hadal trenches.

Insights into the vision of the hadal snailfish Pseudoliparis swirei through proteomic analysis of the eye.

No sunlight can reach the hadal trench, but some fishes dwelling there still have apparent eye morphology. However, whether they are capable of sensing light remains unknown. In this study, the eyes of the dominant hadal endemic snailfish Pseudoliparis swirei from the Mariana Trench were analyzed using liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS). A total of 2088 proteins were identified in the eye proteome, most of which had at least one hit against public databases and could be mapped to 316 metabolic pathways. Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways directly contributing to visual phototransduction were significantly enriched from the top 10% dominant proteins, implying abundant metabolic activities in the eye and it is still a functional visual organ. One rhodopsin was identified in the eye proteome, sequence analysis indicated that it might have an absorption maximum at ∼480 nm and be sensitive to dim blue light. In addition, proteins that might contribute to extreme environment adaptation, such as heat shock proteins and chaperonin-containing T-complex protein 1, were also highly expressed in the eye. Overall, these results provide insights into the molecular mechanism underlying the vision of hadal snailfish and provide a useful database for further research.