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Ultrasound-Guided Paracentesis
Hutchinson’s Sign in Subungual Melanoma In Situ
Is this the future of food? 'Sexless' seeds that could transform farming
Safety and Efficacy of Obicetrapib in Patients at High Cardiovascular Risk
Author Correction: A virtual rodent predicts the structure of neural activity across behaviours
Advancing Physician-Scientist Training in China — Challenges, Gaps, and Future Directions
China’s chikungunya virus outbreak is a wake up call
‘The wolf is not the bad guy’: working with farmers to protect a reintroduced species
States now have a legal duty to prevent climate harm — justice is in reach
Who is afraid of quantum mechanics? Books in brief
Clarity or accuracy — what makes a good scientific image?
Do social-media bans benefit young people? These data could offer clues
When will life expectancy reach 100? No time soon
How researcher visa curbs threaten science careers
Beer lovers fall into two flavour camps — which one are you in?
Even dinosaurs weren’t safe from this giant croc-like predator
Third-party imitation is not restricted to humans
Abstract Imitation of cultural practices is ubiquitous in humans and often involves faithful copying of intransitive (i.e., non-object directed) gestures and societal norms which play a crucial role in human cumulative cultural evolution. Apart from learning these directly from a tutor, humans often learn passively as third-party observers from the interactions of two or more individuals. Whether third-party imitation has evolved outside humans remains unknown. In the current study, we investigated whether undomesticated blue-throated macaws ( Ara glaucogularis ) could imitate in a third-party setting. A naïve test group ( N = 6) passively observed a conspecific demonstrator performing rare intransitive actions in response to specific human gestural commands. Directly afterwards, the observer received the same gestural commands and performance-contingent rewards. An equally naïve control group ( N = 5) was tested correspondingly, in the absence of third-party demonstrations. The test group learned more target actions (mean = 4.16 versus mean = 2.2) in response to the specific commands, significantly faster and performed them more accurately than the control group. The test group also spontaneously imitated some of the actions even before they received any gestural commands or rewards. Our findings show that third-party imitation, even for intransitive actions, exists outside humans, allowing for rapid adaption to group specific behaviours and possibly cultural conventions in parrots.
Estimations of effective doses received from naturally occurring radioactivity in polymetallic nodules from the deep sea
Abstract The strategic importance of metals found in deep-sea polymetallic nodules has spurred a surge in interest for their exploitation. However, nodules are known to incorporate radionuclides during their growth, so that any industrial processing would involve classifying them as naturally occurring radioactive materials (NORM). As the start of deep-sea mining gets closer, concerns about elevated exposure to radiation that could result from the handling of nodules has recently been raised. In this study, we address this issue within the framework of radiation protection regulations. For the first time, we present estimates of effective doses associated with laboratory work and industrial-scale exploitation, transportation and metallurgical processing of polymetallic nodules. Estimates are based on an analysis of all long-lived radionuclides from the three natural decay chains of uranium-238, uranium-235 and thorium-232 and on radon exhalation rates from dry nodules. We show that effective doses for laboratory workplaces are well below the threshold of 1 millisievert per calendar year (mSv/a) for occupational exposure, even under the most conservative assumptions. Furthermore, we find that the effective doses for personnel on nodule transport vessels and metallurgical processing facilities may exceed the threshold in a conservative scenario. However, with standard radiation protection and mitigation measures common in other NORM-affected industries, effective doses can be kept well below the occupational exposure limit.
Physiological responses in free-ranging Asian elephant populations living across human-production landscapes
Abstract Monitoring the physiology of elephants living in human-production landscapes has become increasingly important for understanding how they cope with various challenges that affect their overall fitness. We assessed physiological stress by measuring faecal glucocorticoid metabolite (fGCM) levels and metabolic states using faecal triiodothyronine (fT3) across three free-ranging Asian elephant populations (one in Central India and two in Northeastern India) whose home ranges encompass varying extents of disturbance in human-production landscapes. We present landscape disturbance metrics to characterize variations in fragmentation and anthropogenic pressures across the study landscapes and use faecal carbon and nitrogen (C/N) ratio as a proxy for dietary quality, with higher C/N values indicating poorer-quality diets. Elephants living in more fragmented habitats in Central India had higher fGCM and lower fT3 levels compared to the Northeastern populations, as well as when compared (only fGCM levels) with a previously-studied Southern Indian elephant population. A positive relationship was observed between faecal C/N ratio and fGCM levels across the populations, except for the Central population. These findings suggest that elephants in highly fragmented landscapes and experiencing significant anthropogenic disturbances have (i) higher adrenal activity to cope with and (ii) reduced metabolic rates to conserve energy in emerging challenging contexts. While elephants may adapt to living in human-modified landscapes to some extent, they may experience high stress levels beyond a threshold of disturbance which can be physiologically costly. This warrants systematic assessments to evaluate how these biological costs impact their fitness, and a re-evaluation of conflict management practices.