Changes recorded in cardiac graphoelements bees (Apis mellifera) during contact with fipronil.

A mortality of bees (Apis mellifera) caused by fipronil intoxication, due to its indiscriminate use in crops, has long been attracting the scientific community’s attention, either due to its acute or residual effects. In this study, we assessed the cardiac activity as a biomarker of fipronil intoxication through electrophysiological recordings of bees. Eighteen foragers, from the apiary of EMBRAPA—Eastern Amazon (Belém-Pará), bees were previously anesthetized at low temperature (− 10 °C) for 5 min and properly restrained and fixed on a stereotaxic base, where electrodes were implanted. All these procedures were carried out within a Faraday cage. Eighteen bees were used in the study. Worker bees engaged in foraging activities were selected. The bees were divided into a control group and a group treated with fipronil at 0.025 mg/bee (n = 9). The recordings lasted for 4 min and were evaluated at 1-s intervals represented by the following letters: A = (2–3 s), B = (59–60 s), C = (119–120 s), D = (179–180 s), and E = (239–240 s). The results showed that fipronil reduced the frequency and intensity of cardiac activity, exhibiting rapidly evolving effects, and promoting a disruption of homeostasis in bee hemodynamics. Through the obtained data, it was observed variation in spike amplitude, with a loss of cardiac strength and magnitude of the electrical impulse in the bee’s heart during exposure to fipronil

Stochastic Gravity: Theory and Applications

Whereas semiclassical gravity is based on the semiclassical Einstein equation with sources given by the expectation value of the stress-energy tensor of quantum fields, stochastic semiclassical gravity is based on the Einstein-Langevin equation, which has in addition sources due to the noise kernel. In the first part, we describe the fundamentals of this new theory via two approaches: the axiomatic and the functional. In the second part, we describe three applications of stochastic gravity theory. First, we consider metric perturbations in a Minkowski spacetime, compute the two-point correlation functions of these perturbations and prove that Minkowski spacetime is a stable solution of semiclassical gravity. Second, we discuss structure formation from the stochastic gravity viewpoint. Third, we discuss the backreaction of Hawking radiation in the gravitational background of a black hole and describe the metric fluctuations near the event horizon of an evaporating black holeComment: 100 pages, no figures; an update of the 2003 review in Living Reviews in Relativity gr-qc/0307032 ; it includes new sections on the Validity of Semiclassical Gravity, the Stability of Minkowski Spacetime, and the Metric Fluctuations of an Evaporating Black Hol

EEG-neurofeedback and executive function enhancement in healthy adults: a systematic-review

EEG-neurofeedback training (EEG-NFT) is a promising technique that supports individuals in learning to modulate their brain activity to obtain cognitive and behavioural improvements. EEG-NFT is gaining increasing attention for its potential \u201cpeak performance\u201d applications on healthy individuals. However, evidence for clear cognitive performance enhancements with healthy adults is still lacking. In particular, whether EEG-NFT represents an effective technique for enhancing healthy adults\u2019 executive functions is still controversial. Therefore, the main objective of this systematic-review is to assess whether the existing EEG-NFT studies targeting executive functions have provided reliable evidence for NFT effectiveness. To this end, we conducted a qualitative analysis of the literature since the limited number of retrieved studies did not allow us meta-analytical comparisons. Moreover, a second aim was to identify optimal frequencies as NFT targets for specifically improving executive functions. Overall, our systematic review provides promising evidence for NFT effectiveness in boosting healthy adults\u2019 executive functions. However, more rigorous NFT studies are required in order to overcome the methodological weaknesses that we encountered in our qualitative analysis

Dark Energy Survey Year 3 results: marginalization over redshift distribution uncertainties using ranking of discrete realizations

Cosmological information from weak lensing surveys is maximized by sorting source galaxies into tomographic redshift subsamples. Any uncertainties on these redshift distributions must be correctly propagated into the cosmological results. We present hyperrank, a new method for marginalizing over redshift distribution uncertainties, using discrete samples from the space of all possible redshift distributions, improving over simple parametrized models. In hyperrank, the set of proposed redshift distributions is ranked according to a small (between one and four) number of summary values, which are then sampled, along with other nuisance parameters and cosmological parameters in the Monte Carlo chain used for inference. This approach can be regarded as a general method for marginalizing over discrete realizations of data vector variation with nuisance parameters, which can consequently be sampled separately from the main parameters of interest, allowing for increased computational efficiency. We focus on the case of weak lensing cosmic shear analyses and demonstrate our method using simulations made for the Dark Energy Survey (DES). We show that the method can correctly and efficiently marginalize over a wide range of models for the redshift distribution uncertainty. Finally, we compare hyperrank to the common mean-shifting method of marginalizing over redshift uncertainty, validating that this simpler model is sufficient for use in the DES Year 3 cosmology results presented in companion papers