36 research outputs found
The genomes of two key bumblebee species with primitive eusocial organization
Background: The shift from solitary to social behavior is one of the major evolutionary transitions. Primitively eusocial bumblebees are uniquely placed to illuminate the evolution of highly eusocial insect societies. Bumblebees are also invaluable natural and agricultural pollinators, and there is widespread concern over recent population declines in some species. High-quality genomic data will inform key aspects of bumblebee biology, including susceptibility to implicated population viability threats. Results: We report the high quality draft genome sequences of Bombus terrestris and Bombus impatiens, two ecologically dominant bumblebees and widely utilized study species. Comparing these new genomes to those of the highly eusocial honeybee Apis mellifera and other Hymenoptera, we identify deeply conserved similarities, as well as novelties key to the biology of these organisms. Some honeybee genome features thought to underpin advanced eusociality are also present in bumblebees, indicating an earlier evolution in the bee lineage. Xenobiotic detoxification and immune genes are similarly depauperate in bumblebees and honeybees, and multiple categories of genes linked to social organization, including development and behavior, show high conservation. Key differences identified include a bias in bumblebee chemoreception towards gustation from olfaction, and striking differences in microRNAs, potentially responsible for gene regulation underlying social and other traits. Conclusions: These two bumblebee genomes provide a foundation for post-genomic research on these key pollinators and insect societies. Overall, gene repertoires suggest that the route to advanced eusociality in bees was mediated by many small changes in many genes and processes, and not by notable expansion or depauperation
Surprised at All the Entropy: Hippocampal, Caudate and Midbrain Contributions to Learning from Prediction Errors
Influential concepts in neuroscientific research cast the brain a predictive machine that revises its predictions when they are violated by sensory input. This relates to the predictive coding account of perception, but also to learning. Learning from prediction errors has been suggested for take place in the hippocampal memory system as well as in the basal ganglia. The present fMRI study used an action-observation paradigm to investigate the contributions of the hippocampus, caudate nucleus and midbrain dopaminergic system to different types of learning: learning in the absence of prediction errors, learning from prediction errors, and responding to the accumulation of prediction errors in unpredictable stimulus configurations. We conducted analyses of the regions of interests' BOLD response towards these different types of learning, implementing a bootstrapping procedure to correct for false positives. We found both, caudate nucleus and the hippocampus to be activated by perceptual prediction errors. The hippocampal responses seemed to relate to the associative mismatch between a stored representation and current sensory input. Moreover, its response was significantly influenced by the average information, or Shannon entropy of the stimulus material. In accordance with earlier results, the habenula was activated by perceptual prediction errors. Lastly, we found that the substantia nigra was activated by the novelty of sensory input. In sum, we established that the midbrain dopaminergic system, the hippocampus, and the caudate nucleus were to different degrees significantly involved in the three different types of learning: acquisition of new information, learning from prediction errors and responding to unpredictable stimulus developments. We relate learning from perceptual prediction errors to the concept of predictive coding and related information theoretic accounts
Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries
Abstract
Background
Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres.
Methods
This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries.
Results
In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia.
Conclusion
This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries
The role of the temporoparietal junction (TPJ) in action observation: Agent detection rather than visuospatial transformation
Recognizing and understanding the actions of others is usually coupled with perceiving someone else's body movements from a third person perspective (3pp) whereas we perceive our own actions from a first person perspective (1pp). From a neural viewpoint, a recent finding is that perceiving actions from a 3pp as compared to a 1pp activates the temporoparietal junction, a brain region associated with visuospatial transformation and perspective taking but also with mental state inference and Theory of Mind (ToM). The present fMRI study characterizes the response profile of TPJ to elucidate its role in action observation. Participants observed naturalistic and pixelized object-directed actions from a 3pp and 1pp. Critically, in the pixelized condition the action goal could only be inferred from the movement kinematics. Both left and right TPJ revealed an interaction: Neural activity in TPJ was enhanced for 3pp vs. 1pp actions in the naturalistic but not pixelized condition. This finding contradicts theories proposing that TPJ is generally involved in transforming the action into the observer's perspective to match perceived body movements with visuomotor representations in the observer's motor system, which would be particularly required when actions can only be inferred from movement kinematics. Instead, our results support the theory that perceptual 3pp-selective cues trigger ToM-related processes such as detection of other agents and reasoning about an action's underlying mental states
The neural representation of human versus nonhuman bipeds and quadrupeds
How do humans recognize humans among other creatures? Recent studies suggest that a preference for conspecifics may emerge already in perceptual processing, in regions such as the right posterior superior temporal sulcus (pSTS), implicated in visual perception of biological motion. In the current functional MRI study, participants viewed point-light displays of human and nonhuman creatures moving in their typical bipedal (man and chicken) or quadrupedal mode (crawling-baby and cat). Stronger activity for man and chicken versus baby and cat was found in the right pSTS responsive to biological motion. The novel effect of pedalism suggests that, if right pSTS contributes to recognizing of conspecifics, it does so by detecting perceptual features (e.g. bipedal motion) that reliably correlate with their appearance. A searchlight multivariate pattern analysis could decode humans and nonhumans across pedalism in the left pSTS and bilateral posterior cingulate cortex. This result implies a categorical human-nonhuman distinction, independent from within-category physical/perceptual variation. Thus, recognizing conspecifics involves visual classification based on perceptual features that most frequently co-occur with humans, such as bipedalism, and retrieval of information that determines category membership above and beyond visual appearance. The current findings show that these processes are at work in separate brain networks
Decoding Concrete and Abstract Action Representations During Explicit and Implicit Conceptual Processing
Action understanding requires a many-to-one mapping of perceived input onto abstract representations that generalize across concrete features. It is debated whether such abstract action concepts are encoded in ventral premotor cortex (PMv; motor hypothesis) or, alternatively, are represented in lateral occipitotemporal cortex (LOTC; cognitive hypothesis). We used fMRI-based multivoxel pattern analysis to decode observed actions at concrete and abstract, object-independent levels of representation. Participants observed videos of 2 actions involving 2 different objects, using either an explicit or implicit task with respect to conceptual action processing. We decoded concrete action representations by training and testing a classifier to discriminate between actions within each object category. To identify abstract action representations, we trained the classifier to discriminate actions in one object and tested the classifier on actions performed on the other object, and vice versa. Region-of-interest and searchlight analyses revealed decoding in LOTC at both concrete and abstract levels during both tasks, whereas decoding in PMv was restricted to the concrete level during the explicit task. In right inferior parietal cortex, decoding was significant for the abstract level during the explicit task. Our findings are incompatible with the motor hypothesis, but support the cognitive hypothesis of action understanding