Two brains in action: joint-action coding in the primate frontal cortex

Daily life often requires the coordination of our actions with those of another partner. After sixty years (1968-2018) of behavioral neurophysiology of motor control, the neural mechanisms which allow such coordination in primates are unknown. We studied this issue by recording cell activity simultaneously from dorsal premotor cortex (PMd) of two male interacting monkeys trained to coordinate their hand forces to achieve a common goal. We found a population of 'joint-action cells' that discharged preferentially when monkeys cooperated in the task. This modulation was predictive in nature, since in most cells neural activity led in time the changes of the "own" and of the "other" behavior. These neurons encoded the joint-performance more accurately than 'canonical action-related cells', activated by the action per se, regardless of the individual vs. interactive context. A decoding of joint-action was obtained by combining the two brains activities, using cells with directional properties distinguished from those associated to the 'solo' behaviors. Action observation-related activity studied when one monkey observed the consequences of the partner's behavior, i.e. the cursor's motion on the screen, did not sharpen the accuracy of 'joint-action cells' representation, suggesting that it plays no major role in encoding joint-action. When monkeys performed with a non-interactive partner, such as a computer, 'joint-action cells' representation of the "other" (non-cooperative) behavior was significantly degraded. These findings provide evidence of how premotor neurons integrate the time-varying representation of the self-action with that of a co-actor, thus offering a neural substrate for successful visuo-motor coordination between individuals.SIGNIFICANT STATEMENTThe neural bases of inter-subject motor coordination were studied by recording cell activity simultaneously from the frontal cortex of two interacting monkeys, trained to coordinate their hand forces to achieve a common goal. We found a new class of cells, preferentially active when the monkeys cooperated, rather than when the same action was performed individually. These 'joint-action neurons' offered a neural representation of joint-behaviors by far more accurate than that provided by the canonical action-related cells, modulated by the action per se regardless of the individual/interactive context. A neural representation of joint-performance was obtained by combining the activity recorded from the two brains. Our findings offer the first evidence concerning neural mechanisms subtending interactive visuo-motor coordination between co-acting agents

Tracing megafaunal extinctions with dung fungal spores

animals went extinct across extensive areas of the planet (Martin & Klein, 1984; MacPhee, 1999). Although a widespread phenomenon, late Quaternary extinctions of the so-called ‘megafauna’ varied greatly in intensity and timing around the world. So, while Europe, Asia, and Africa experienced only limited losses toward the end of the Pleistocene, the Americas, Australia, Madagascar and many Oceanic islands suffered dramatic extinctions. In North America, more than two-thirds of the mammals weighing more than 44 kg disappeared about 11,000 years ago (Alroy, 2001). Nearly at the same time, in South America most of the species of medium to large mammals also vanished. Australia witnessed an even more catastrophic continent-wide die-off. Some 23 of the 24 genera of Australian land vertebrates with a body mass of 45 to 1000 kilograms had died out by around 46,000 years ago (Roberts et al., 2001). The casualties of this ‘marvellous fact’, as the English naturalist Alfred Russell Wallace called it over a century ago (Wallace, 1876), bear exotic names that evoke fantastic images. Among them were fearsome claw-footed kangaroos that weighed 300 kilograms and the giant marsupial equivalents of rhinoceros and leopard in Australia. Somewhat later in North America, sabre-toothed cats, giant bisons, mammoths, mastodons, and also less well known mammals like the short-faced bear and the giant beaver went extinct. The whopping half-ton elephant birds, the heaviest birds ever known, giant lemurs and other strange beasts disappeared from the island of Madagascar within the last millennium (Burney, 1999)

Servizi postali

The paper discusses the evolutionary path of the European postal industry turned from a inefficient state-owned monopoly into highly competitive market, in sight of the envisaged market liberalization by the year 2011. National operators adopt different strategies toward the increasing competition. France and the UK are willing to maintain Universal Service Obligations and an access regime to their delivery networks. The Netherlands, Germany and Scandinavian countries instead favor value-added services, intermediate between ordinary letters and the express courier. While the former base their strategy by maintaining free, universal and non excludable letter delivery, the latter may introduce new charges in delivery. The industry face the so called e-substitution, arising when paper letters are substituted by e-mails.

Birth registration and child undernutrition in sub-Saharan Africa

The database comprises data on malnutrition and birth registration rates in 33 sub-Saharan African Countries as retrieved by DHS (http://www.dhsprogram.com) and MICS (http://www.childinfo.org/mics.html) reports. The study protocol includes detailed information on data selection and statistical analyses

Social threat exposure in juvenile mice promotes cocaine-seeking by altering blood clotting and brain vasculature

Childhood maltreatment is associated with increased severity of substance use disorder and frequent relapse to drug use following abstinence. However, the molecular and neurobiological substrates that are engaged during early traumatic events and mediate the greater risk of relapse are poorly understood and knowledge of risk factors is to date extremely limited. In this study, we modeled childhood maltreatment by exposing juvenile mice to a threatening social experience (social stressed, S-S). We showed that S-S experience influenced the propensity to reinstate cocaineseeking after periods of withdrawal in adulthood. By exploring global gene expression in blood leukocytes we found that this behavioral phenotype was associated with greater blood coagulation. In parallel, impairments in brain microvasculature were observed in S-S mice. Furthermore, treatment with an anticoagulant agent during withdrawal abolished the susceptibility to reinstate cocaine-seeking in S-S mice. These findings provide novel insights into a possible molecular mechanism by which childhood maltreatment heightens the risk for relapse in cocaine-dependent individuals

Facial Emotion Recognition and Expression in Parkinson's Disease: An Emotional Mirror Mechanism?

BACKGROUND AND AIM: Parkinson's disease (PD) patients have impairment of facial expressivity (hypomimia) and difficulties in interpreting the emotional facial expressions produced by others, especially for aversive emotions. We aimed to evaluate the ability to produce facial emotional expressions and to recognize facial emotional expressions produced by others in a group of PD patients and a group of healthy participants in order to explore the relationship between these two abilities and any differences between the two groups of participants. METHODS: Twenty non-demented, non-depressed PD patients and twenty healthy participants (HC) matched for demographic characteristics were studied. The ability of recognizing emotional facial expressions was assessed with the Ekman 60-faces test (Emotion recognition task). Participants were video-recorded while posing facial expressions of 6 primary emotions (happiness, sadness, surprise, disgust, fear and anger). The most expressive pictures for each emotion were derived from the videos. Ten healthy raters were asked to look at the pictures displayed on a computer-screen in pseudo-random fashion and to identify the emotional label in a six-forced-choice response format (Emotion expressivity task). Reaction time (RT) and accuracy of responses were recorded. At the end of each trial the participant was asked to rate his/her confidence in his/her perceived accuracy of response. RESULTS: For emotion recognition, PD reported lower score than HC for Ekman total score (p<0.001), and for single emotions sub-scores happiness, fear, anger, sadness (p<0.01) and surprise (p = 0.02). In the facial emotion expressivity task, PD and HC significantly differed in the total score (p = 0.05) and in the sub-scores for happiness, sadness, anger (all p<0.001). RT and the level of confidence showed significant differences between PD and HC for the same emotions. There was a significant positive correlation between the emotion facial recognition and expressivity in both groups; the correlation was even stronger when ranking emotions from the best recognized to the worst (R = 0.75, p = 0.004). CONCLUSIONS: PD patients showed difficulties in recognizing emotional facial expressions produced by others and in posing facial emotional expressions compared to healthy subjects. The linear correlation between recognition and expression in both experimental groups suggests that the two mechanisms share a common system, which could be deteriorated in patients with PD. These results open new clinical and rehabilitation perspectives

Prospects for the Higgs boson self-coupling measurement with the Phase-II CMS detector upgrade using simulated pp collisions at √s = 27 TeV (High Energy LHC)

The performance of the HH->bbZZ (l) (l = e, mu) analysis is presented considering the possible High Energy upgrade of the LHC collider, at a center-of-mass energy of √s = 27 TeV and with an integrated luminosity of 15000 fb^{-1}; a comparison of the results with the same study performed in the context of the High Luminosity LHC, at a center-of-mass energy of √s =14 TeV and with an integrated luminosity of 3000 fb^{-1}, is also reported. The Phase-II upgraded CMS detector, expected in 2024, is assumed in both the scenarios. The analysis is fully based on Monte Carlo simulations: the parton-level generation of signal and backgrounds is performed with MADGRAPH5_AMC@NLO, while parton showering and hadronization are achieved with PYTHIA8; the detector response is then obtained in the parametric framework provided by DELPHES. A limit on the di-Higgs signal strength of r =1.45 is estimated at 95% CL in the inclusive bb4l channel, with a corresponding signal significance of 1.43 σ. A study on the prospects for the measurements of the Higgs self-coupling (λ_3) is also performed: the projected confidence interval on k_λ = λ_3/λ_3^{SM} is found to be [-0.7,7.2] at the 95% CL

Sign-to-contract : how to achieve trustless digital timestamping with zero marginal cost

LAUREA MAGISTRALEDimostrare che un particolare dato esisteva prima di un determinato istante è utile in diverse situazioni. Grazie a sistemi che raggiungono un consenso distribuito senza fare affidamento su una terza parte fidata, come Bitcoin, è possibile migliorare la sicurezza di tali marcature temporali, dette anche timestamp. OpenTimestamps è un protocollo che definisce uno standard per la creazione di timestamp e, inoltre, fornisce una soluzione di scalabilità. Attualmente è stato proposto un miglioramento che utilizza i punti della curva ellittica come ancoraggio. Miriamo a dare una panoramica completa su questo nuovo schema, le sue implicazioni e motivazioni, culminando nello sviluppo di un'applicazione reale.Proving that data existed prior to a certain time is helpful in several situations. Thanks to systems achieving distributed consensus without relying on a trusted third party, like Bitcoin, it is possible to enhance the security of such timestamps. OpenTimestamps is a protocol defining a standard for creating timestamps and, in addition, it provides a scalability solution. Currently, an improvement concerning elliptic curve commitments has been proposed. We aim to give an exhaustive overview upon this new scheme, its implications and motivations, culminating in the development of a real world application

Different genes interact with particulate matter and tobacco smoke exposure in affecting lung function decline in the general population

BACKGROUND: Oxidative stress related genes modify the effects of ambient air pollution or tobacco smoking on lung function decline. The impact of interactions might be substantial, but previous studies mostly focused on main effects of single genes. OBJECTIVES: We studied the interaction of both exposures with a broad set of oxidative-stress related candidate genes and pathways on lung function decline and contrasted interactions between exposures. METHODS: For 12679 single nucleotide polymorphisms (SNPs), change in forced expiratory volume in one second (FEV(1)), FEV(1) over forced vital capacity (FEV(1)/FVC), and mean forced expiratory flow between 25 and 75% of the FVC (FEF(25-75)) was regressed on interval exposure to particulate matter >10 microm in diameter (PM10) or packyears smoked (a), additive SNP effects (b), and interaction terms between (a) and (b) in 669 adults with GWAS data. Interaction p-values for 152 genes and 14 pathways were calculated by the adaptive rank truncation product (ARTP) method, and compared between exposures. Interaction effect sizes were contrasted for the strongest SNPs of nominally significant genes (p(interaction)>0.05). Replication was attempted for SNPs with MAF<10% in 3320 SAPALDIA participants without GWAS. RESULTS: On the SNP-level, rs2035268 in gene SNCA accelerated FEV(1)/FVC decline by 3.8% (p(interaction) = 2.5x10(-6)), and rs12190800 in PARK2 attenuated FEV1 decline by 95.1 ml p(interaction) = 9.7x10(-8)) over 11 years, while interacting with PM10. Genes and pathways nominally interacting with PM10 and packyears exposure differed substantially. Gene CRISP2 presented a significant interaction with PM10 (p(interaction) = 3.0x10(-4)) on FEV(1)/FVC decline. Pathway interactions were weak. Replications for the strongest SNPs in PARK2 and CRISP2 were not successful. CONCLUSIONS: Consistent with a stratified response to increasing oxidative stress, different genes and pathways potentially mediate PM10 and tobac smoke effects on lung function decline. Ignoring environmental exposures would miss these patterns, but achieving sufficient sample size and comparability across study samples is challengin