Formation of the methyl cation by photochemistry in a protoplanetary disk.

Forty years ago, it was proposed that gas-phase organic chemistry in the interstellar medium can be initiated by the methyl cation CH3+ (refs. 1-3), but so far it has not been observed outside the Solar System4,5. Alternative routes involving processes on grain surfaces have been invoked6,7. Here we report James Webb Space Telescope observations of CH3+ in a protoplanetary disk in the Orion star-forming region. We find that gas-phase organic chemistry is activated by ultraviolet irradiation.

Subjective age of acquisition norms for 1604 English words by Spanish L2 speakers of English and their relationship with lexico-semantic, affective, sociolinguistic and proficiency variables.

Psycholinguistic studies have shown that there are many variables implicated in language comprehension and production. At the lexical level, subjective age of acquisition (AoA), the estimate of the age at which a word is acquired, is key for stimuli selection in psycholinguistic studies. AoA databases in English are often used when testing a variety of phenomena in second language (L2) speakers of English. However, these have limitations, as the norms are not provided by the target population (L2 speakers of English) but by native English speakers. In this study, we asked native Spanish L2 speakers of English to provide subjective AoA ratings for 1604 English words, and investigated whether factors related to 14 lexico-semantic and affective variables, both in Spanish and English, and to the speakers' profile (i.e., sociolinguistic variables and L2 proficiency), were related to the L2 AoA ratings. We used boosted regression trees, an advanced form of regression analysis based on machine learning and boosting algorithms, to analyse the data. Our results showed that the model accounted for a relevant proportion of deviance (58.56%), with the English AoA provided by native English speakers being the strongest predictor for L2 AoA. Additionally, L2 AoA correlated with L2 reaction times. Our database is a useful tool for the research community running psycholinguistic studies in L2 speakers of English. It adds knowledge about which factors-linked to the characteristics of both the linguistic stimuli and the speakers-affect L2 subjective AoA. The database and the data can be downloaded from: https://osf.io/gr8xd/?view_only=73b01dccbedb4d7897c8d104d3d68c46 .

Compression and ablation of the photo-irradiated molecular cloud the Orion Bar.

The Orion Bar is the archetypal edge-on molecular cloud surface illuminated by strong ultraviolet radiation from nearby massive stars. Our relative closeness to the Orion nebula (about 1,350 light years away from Earth) means that we can study the effects of stellar feedback on the parental cloud in detail. Visible-light observations of the Orion Bar show that the transition between the hot ionized gas and the warm neutral atomic gas (the ionization front) is spatially well separated from the transition between atomic and molecular gas (the dissociation front), by about 15 arcseconds or 6,200 astronomical units (one astronomical unit is the Earth-Sun distance). Static equilibrium models used to interpret previous far-infrared and radio observations of the neutral gas in the Orion Bar (typically at 10-20 arcsecond resolution) predict an inhomogeneous cloud structure comprised of dense clumps embedded in a lower-density extended gas component. Here we report one-arcsecond-resolution millimetre-wave images that allow us to resolve the molecular cloud surface. In contrast to stationary model predictions, there is no appreciable offset between the peak of the H2 vibrational emission (delineating the H/H2 transition) and the edge of the observed CO and HCO+ emission. This implies that the H/H2 and C+/C/CO transition zones are very close. We find a fragmented ridge of high-density substructures, photoablative gas flows and instabilities at the molecular cloud surface. The results suggest that the cloud edge has been compressed by a high-pressure wave that is moving into the molecular cloud, demonstrating that dynamical and non-equilibrium effects are important for the cloud evolution.

A far-ultraviolet-driven photoevaporation flow observed in a protoplanetary disk.

Most low-mass stars form in stellar clusters that also contain massive stars, which are sources of far-ultraviolet (FUV) radiation. Theoretical models predict that this FUV radiation produces photodissociation regions (PDRs) on the surfaces of protoplanetary disks around low-mass stars, which affects planet formation within the disks. We report James Webb Space Telescope and Atacama Large Millimeter Array observations of a FUV-irradiated protoplanetary disk in the Orion Nebula. Emission lines are detected from the PDR; modeling their kinematics and excitation allowed us to constrain the physical conditions within the gas. We quantified the mass-loss rate induced by the FUV irradiation and found that it is sufficient to remove gas from the disk in less than a million years. This is rapid enough to affect giant planet formation in the disk.

Replacing academic journals.

Replacing traditional journals with a more modern solution is not a new idea. Here, we propose ways to overcome the social dilemma underlying the decades of inaction. Any solution needs to not only resolve the current problems but also be capable of preventing takeover by corporations: it needs to replace traditional journals with a decentralized, resilient, evolvable network that is interconnected by open standards and open-source norms under the governance of the scholarly community. It needs to replace the monopolies connected to journals with a genuine, functioning and well-regulated market. In this new market, substitutable service providers compete and innovate according to the conditions of the scholarly community, avoiding sustained vendor lock-in. Therefore, a standards body needs to form under the governance of the scholarly community to allow the development of open scholarly infrastructures servicing the entire research workflow. We propose a redirection of money from legacy publishers to the new network by funding bodies broadening their minimal infrastructure requirements at recipient institutions to include modern infrastructure components replacing and complementing journal functionalities. Such updated eligibility criteria by funding agencies would help realign the financial incentives for recipient institutions with public and scholarly interest.

Would You Sacrifice Yourself to Save Five Lives? Processing a Foreign Language Increases the Odds of Self-Sacrifice in Moral Dilemmas.

Foreign languages blunt emotional reactions to moral dilemmas. In this study, we aimed at clarifying whether this reduced emotional response applies to the emotions related to the self, empathy, or both. Participants were presented with moral dilemmas, written in their native or foreign language, in which they could sacrifice one man or themselves in order to save five lives (or do nothing and therefore leave five people to die). They were more willing to sacrifice themselves when processing the dilemmas in their foreign language. Also, empathy scores were reduced when responding in the foreign language, but were no reliable predictors of participants' responses to the dilemmas. These results suggest that processing a foreign language reduces emotional reactivity due to psychological and emotional self-distance.

The Psychological Impact of the COVID-19 Pandemic Affected Decision-Making Processes.

A sample of 641 participants were presented with four decision-making tasks during the first stages of the COVID-19 lockdown in Spain: The dictator game, framing problems, utilitarian/deontological and altruistic/egoistic moral dilemmas. Participants also completed questionnaires on mental health status and experiences related to the COVID-19 pandemic. We used boosted regression trees (an advanced form of regression analysis based on machine learning) to model relationships between responses to the questionnaires and decision-making tasks. Results showed that the psychological impact of the COVID-19 pandemic predicted participants' responses to the framing problems and utilitarian/deontological and altruistic/egoistic moral dilemmas (but not to the dictator game). More concretely, the more psychological impact participants suffered, the more they were willing to choose the safest response in the framing problems, and the more deontological/altruistic were their responses to moral dilemmas. These results suggest that the psychological impact of the COVID-19 pandemic might prompt automatic processes.

On the Nature of the Word-Reduction Phenomenon: The Contribution of Bilingualism.

Word reduction refers to how predictable words are shortened in features such as duration, intensity, or pitch. However, its origin is still unclear: Are words reduced because it is the second time that conceptual representations are activated, or because words are articulated twice? If word reduction is conceptually driven, it would be irrelevant whether the same referent is mentioned twice but using different words. However, if is articulatory, using different words for the same referent could prevent word reduction. In the present work, we use bilingualism to explore the conceptual or articulatory origin of word reduction in language production. Word reduction was compared in two conditions: a non-switch condition, where the two mentions of a referent were uttered in the same language, and a switch condition, where the referent was said in both languages. Dyads of participants completed collaborative maps in which words were uttered twice in Catalan or in Spanish, either repeating or switching the language between mentions. Words were equally reduced in duration, intensity, and pitch in non-switch and in switch conditions. Furthermore, the cognate status of words did not play any role. These findings support the theory that word reduction is conceptually driven.

Molecular tracers of radiative feedback in Orion (OMC-1) Widespread CH+ (J = 1-0), CO (10-9), HCN (6-5), and HCO+ (6-5) emission.

Young massive stars regulate the physical conditions, ionization, and fate of their natal molecular cloud and surroundings. It is important to find tracers that help quantifying the stellar feedback processes that take place at different spatial scales. We present ~85 arcmin2 (~1.3 pc2) velocity-resolved maps of several submillimeter molecular lines, taken with Herschel/HIFI, toward the closest high-mass star-forming region, the Orion molecular cloud 1 core (OMC-1). The observed rotational lines include probes of warm and dense molecular gas that are difficult, if not impossible, to detect from ground-based telescopes: CH+ (J = 1-0), CO (J = 10-9), HCO+ (J = 6-5) and HCN (J = 6-5), and CH (N, J =1, 3/2-1, 1/2). These lines trace an extended but thin layer (A V ≃3-6 mag or ~1016 cm) of molecular gas at high thermal pressure, P th = n H · T k ≈ 107 - 109 cm-3 K, associated with the far ultraviolet (FUV) irradiated surface of OMC-1. The intense FUV radiation field, emerging from massive stars in the Trapezium cluster, heats, compresses and photoevaporates the cloud edge. It also triggers the formation of specific reactive molecules such as CH+. We find that the CH+ (J = 1-0) emission spatially correlates with the flux of FUV photons impinging the cloud: G 0 from ~103 to ~105. This correlation is supported by constant-pressure photodissociation region (PDR) models in the parameter space P th/G 0 ≈ [5 · 103 - 8 · 104] cm-3 K where many observed PDRs seem to lie. The CH+ (J = 1-0) emission spatially correlates with the extended infrared emission from vibrationally excited H2 (v ≥ 1), and with that of [C ii] 158 µm and CO J = 10-9, all emerging from FUV-irradiated gas. These correlations link the presence of CH+ to the availability of C+ ions and of FUV-pumped H2 (v ≥ 1) molecules. We conclude that the parsec-scale CH+ emission and narrow-line (Δv ≃ 3 km s-1) mid-J CO emission arises from extended PDR gas and not from fast shocks. PDR line tracers are the smoking gun of the stellar feedback from young massive stars. The PDR cloud surface component in OMC-1, with a mass density of 120-240 M ⊙ pc-2, represents ~5% to ~10% of the total gas mass, however, it dominates the emitted line luminosity; the average CO J = 10-9 surface luminosity in the mapped region being ~35 times brighter than that of CO J = 2-1. These results provide insights into the source of submillimeter CH+ and mid-J CO emission from distant star-forming galaxies.

Differential control of isocitrate lyase gene transcription by non-fermentable carbon sources in the milk yeast Kluyveromyces lactis.

The KlICL1 gene, encoding isocitrate lyase in Kluyveromyces lactis, is essential for ethanol utilization. Deletion analyses identified two functional promoter elements, CSRE-A and CSRE-B. Transcription is activated on ethanol, but not on glucose, glycerol or lactate. Expression depends on the KlCat8p transcription factor and KlSip4p binds to the promoter elements. Glycerol diminishes KlICL1 expression and a single carbon source responsive element (CSRE) sequence is both necessary and sufficient to mediate this regulation. The glycerol effect is less pronounced in Saccharomyces cerevisiae than in K. lactis. Mutants lacking KlGUT2 (which encodes the glycerol 3-phosphate dehydrogenase) still show reduced expression in glycerol, whereas mutants deficient in glycerol kinase (Klgut1) do not. We conclude that a metabolite of glycerol is required for this regulation.

Seeing music: The perception of melodic 'ups and downs' modulates the spatial processing of visual stimuli.

Musical melodies have "peaks" and "valleys". Although the vertical component of pitch and music is well-known, the mechanisms underlying its mental representation still remain elusive. We show evidence regarding the importance of previous experience with melodies for crossmodal interactions to emerge. The impact of these crossmodal interactions on other perceptual and attentional processes was also studied. Melodies including two tones with different frequency (e.g., E4 and D3) were repeatedly presented during the study. These melodies could either generate strong predictions (e.g., E4-D3-E4-D3-E4-[D3]) or not (e.g., E4-D3-E4-E4-D3-[?]). After the presentation of each melody, the participants had to judge the colour of a visual stimulus that appeared in a position that was, according to the traditional vertical connotations of pitch, either congruent (e.g., high-low-high-low-[up]), incongruent (high-low-high-low-[down]) or unpredicted with respect to the melody. Behavioural and electroencephalographic responses to the visual stimuli were obtained. Congruent visual stimuli elicited faster responses at the end of the experiment than at the beginning. Additionally, incongruent visual stimuli that broke the spatial prediction generated by the melody elicited larger P3b amplitudes (reflecting 'surprise' responses). Our results suggest that the passive (but repeated) exposure to melodies elicits spatial predictions that modulate the processing of other sensory events.

Spatially resolved images of reactive ions in the Orion Bar,☠☠.

We report high angular resolution (4.9″×3.0″) images of reactive ions SH+, HOC+, and SO+ toward the Orion Bar photodissociation region (PDR). We used ALMA-ACA to map several rotational lines at 0.8 mm, complemented with multi-line observations obtained with the IRAM 30 m telescope. The SH+ and HOC+ emission is restricted to a narrow layer of 2″- to 10″-width (≈800 to 4000 AU depending on the assumed PDR geometry) that follows the vibrationally excited [Formula: see text] emission. Both ions efficiently form very close to the H/H2 transition zone, at a depth of Av≲1 mag into the neutral cloud, where abundant C+, S+, and [Formula: see text] coexist. SO+ peaks slightly deeper into the cloud. The observed ions have low rotational temperatures (Trot≈10-30 K≪Tk) and narrow line-widths (~2-3 km s-1), a factor of ≃2 narrower that those of the lighter reactive ion CH+. This is consistent with the higher reactivity and faster radiative pumping rates of CH+ compared to the heavier ions, which are driven relatively faster toward smaller velocity dispersion by elastic collisions and toward lower Trot by inelastic collisions. We estimate column densities and average physical conditions from an excitation model (n(H2)≈105-106 cm-3, n(e-)≈10 cm-3, and Tk≈200 K). Regardless of the excitation details, SH+ and HOC+ clearly trace the most exposed layers of the UV-irradiated molecular cloud surface, whereas SO+ arises from slightly more shielded layers.

Processing advantage for emotional words in bilingual speakers.

Effects of emotion on word processing are well established in monolingual speakers. However, studies that have assessed whether affective features of words undergo the same processing in a native and nonnative language have provided mixed results: Studies that have found differences between native language (L1) and second language (L2) processing attributed the difference to the fact that L2 learned late in life would not be processed affectively, because affective associations are established during childhood. Other studies suggest that adult learners show similar effects of emotional features in L1 and L2. Differences in affective processing of L2 words can be linked to age and context of learning, proficiency, language dominance, and degree of similarity between L2 and L1. Here, in a lexical decision task on tightly matched negative, positive, and neutral words, highly proficient English speakers from typologically different L1s showed the same facilitation in processing emotionally valenced words as native English speakers, regardless of their L1, the age of English acquisition, or the frequency and context of English use.

Revised spectroscopic parameters of SH(+) from ALMA and IRAM 30m observations.

Hydrides represent the first steps of interstellar chemistry. Sulfanylium (SH(+)), in particular, is a key tracer of energetic processes. We used ALMA and the IRAM 30 m telescope to search for the lowest frequency rotational lines of SH(+) toward the Orion Bar, the prototypical photo-dissociation region illuminated by a strong UV radiation field. On the basis of previous Herschel/HIFI observations of SH(+), we expected to detect emission of the two SH(+) hyperfine structure (HFS) components of the NJ = 10-01 fine structure (FS) component near 346 GHz. While we did not observe any lines at the frequencies predicted from laboratory data, we detected two emission lines, each ~15 MHz above the SH(+) predictions and with relative intensities and HFS splitting expected for SH(+). The rest frequencies of the two newly detected lines are more compatible with the remainder of the SH(+) laboratory data than the single line measured in the laboratory near 346 GHz and previously attributed to SH(+). Therefore, we assign these new features to the two SH(+) HFS components of the NJ = 10-01 FS component and re-determine its spectroscopic parameters, which will be useful for future observations of SH(+), in particular if its lowest frequency FS components are studied. Our observations demonstrate the suitability of these lines for SH(+) searches at frequencies easily accessible from the ground.

Coming of age: a review of embodiment and the neuroscience of semantics.

Over the last decade, there has been an increasing body of work that explores whether sensory and motor information is a necessary part of semantic representation and processing. This is the embodiment hypothesis. This paper presents a theoretical review of this work that is intended to be useful for researchers in the neurosciences and neuropsychology. Beginning with a historical perspective, relevant theories are placed on a continuum from strongly embodied to completely unembodied representations. Predictions are derived and neuroscientific and neuropsychological evidence that could support different theories is reviewed; finally, criticisms of embodiment are discussed. We conclude that strongly embodied and completely disembodied theories are not supported, and that the remaining theories agree that semantic representation involves some form of convergence zones (Damasio, 1989) and the activation of modal content. For the future, research must carefully define the boundaries of semantic processing and tackle the representation of abstract entities.