New York University Paris

A general study is given of the polarization of light scattered by isotropic media whose elements of heterogeneity are not very small in comparison with the wavelength, (suspensions, colloidal solutions, solutions of large molecules, ...). This includes an extension of a theory by R. S. Krishnan, who, considering certain particular states of polarization of the incident light and applying the law of reciprocity, had proved the equality of two of the four coefficients which are to be considered in these cases. Using Stokes' linear representation of the polarization of light beams, it is shown that the scattering through a given angle and for a given wave-length is characterized by the 16 coefficients of the linear forms which express the four polarization parameters of the scattered beam in terms of the four corresponding parameters of the incident beam and that the law of reciprocity leads to six relations between these sixteen coefficients. For an isotropic asymmetrical medium (having rotatory power), the scattering is thus characterized by ten independent coefficients. In the case of a symmetrical medium, four of these coefficients must be zero, leaving only six scattering coefficients, and if the scattering particles are spherical, there are two additional relations between these coefficients. The comparison with dipolar scattering by very small elements shows that the best test to prove multipolar scattering is the existence of some ellipticity in the scattered light when the incident beam is linearly polarized in a direction oblique to the scattering plane.

The prognostic role of circulating tumor cells (CTCs) has been clearly demonstrated in many types of cancer. However, their roles in diagnostic and treatment strategies remain to be defined. In this review, we present an overview of the current clinical validity of CTCs in nonmetastatic and metastatic cancer, and the main studies or concepts investigating the clinical utility of CTCs. In particular, we focus on breast, lung, colorectal, and prostate cancer. Two major topics concerning the clinical utility of CTC are discussed: treatment based on CTC count or CTC variations, and treatment based on the molecular characteristics of CTCs. Although some of these studies are inconclusive, many are still ongoing, and their results could help to define the role of CTCs in the management of cancers. A summary of published or ongoing phase II-III trials is also presented.

1. This review summarises knowledge on the ecology, toxin production, and impacts of toxic freshwater benthic cyanobacterial proliferations. It documents monitoring, management, and sampling strategies, and explores mitigation options. 2. Toxic proliferations of freshwater benthic cyanobacteria (taxa that grow attached to substrates) occur in streams, rivers, lakes, and thermal and meltwater ponds, and have been reported in 19 countries. Anatoxin- and microcystin-containing mats are most commonly reported (eight and 10 countries, respectively). 3. Studies exploring factors that promote toxic benthic cyanobacterial proliferations are limited to a few species and habitats. There is a hierarchy of importance in environmental and biological factors that regulate proliferations with variables such as flow (rivers), fine sediment deposition, nutrients, associated microbes, and grazing identified as key drivers. Regulating factors differ among colonisation, expansion, and dispersal phases. 4. New -omics-based approaches are providing novel insights into the physiological attributes of benthic cyanobacteria and the role of associated microorganisms in facilitating their proliferation. 5. Proliferations are commonly comprised of both toxic and non-toxic strains, and the relative proportion of these is the key factor contributing to the overall toxin content of each mat. 6. While these events are becoming more commonly reported globally, we currently lack standardised approaches to detect, monitor, and manage this emerging health issue. To solve these critical gaps, global collaborations are needed to facilitate the rapid transfer of knowledge and promote the development of standardised techniques that can be applied to diverse habitats and species, and ultimately lead to improved management.

On 17 March 2020, a national lockdown began in France in response to the COVID-19 pandemic. Loneliness and social isolation caused by social distancing are long-established major risk factors for a number of psychiatric disorders.1, 2 Quarantine and lockdown have other psychological consequences, such as boredom, irritability, and sleep dysregulation, which are associated with first-episode emergence of psychiatric disorders as well as the exacerbation of pre-existing psychiatric conditions.3, 4 Contamination fear has additional stress associations, for example anxious and obsessional symptoms, or delusional symptoms.5 In addition, psychiatric services have had to be reorganized5, 6 to reduce contact among patients and between patients and professionals; for example, restricting consultations to severe cases; reorganization of health care via teleconsultation; early hospital release and restrictions on new hospitalizations; and closure of daily care facilities. Consequently, patients may have experienced difficulties in accessing psychiatric services or worry about being fined for non-compliance of lockdown rules. Overall, such factors may create a treatment gap and/or lead to a break in follow-up and ongoing treatment, thereby increasing emergency consultations during lockdown.7 This study aimed to compare the number and characteristics of emergency psychiatric consultations during the first 4 weeks of the lockdown in three psychiatric emergency services from Paris and its suburbs, and to compare them to the same period in 2019. Three psychiatric emergency centers took part in the study: one in Paris, and one each in adjacent suburban cities, Colombes and Créteil. We assessed and compared the number and characteristics of emergency consultations during the first 4 weeks of the French lockdown and of the corresponding weeks of 2019. The data from the three centers were pooled. Concerning the categorical variables, the proportions of each sociodemographic, clinical, and outcome category were compared between 2019 and 2020 using two-tailed χ2-tests, with the null hypothesis of an absence of difference between 2019 and 2020. Additional details concerning the data collection and statistical analyses are available in the supplementary materials (Appendix S1). The study was performed in accordance with the Declaration of Helsinki. The data were extracted anonymously from registers, in accordance with the ethical standards of the French National Data Protection Authority. During the first 4 weeks of the national COVID-19-related lockdown, 553 emergency psychiatric consultations were carried out, representing less than half (45.2%) of the corresponding weeks in 2019 (1224 consultations). This decrease was evident in each of the three centers. The decrease concerned all psychiatric diagnoses, especially for anxiety disorders (number of consultations in 2020 representing 36.1% of consultations in 2019), mood disorders (41.1%), and psychotic disorders (67.2%). Total suicide attempts also decreased in 2020 to 42.6% of those in 2019. The diagnostic pattern of presentations significantly changed, with the percentage of consultations for psychotic disorders increasing (31.1% in 2020 vs 24.1% in 2019), and the percentage of anxiety and stress-related disorders decreasing (16.6% vs 20.8%). The rate of first-episode psychiatric consultations decreased (13.8% vs 20.1%). Hospitalization without patients' consent increased (54.2% vs 43.8%). More details are available in Table 1. Given the multifaceted stressors associated with lockdown, the above results show a surprising 54.8% drop in the number of psychiatric emergency consultations during the first 4 weeks of the COVID-19 pandemic. This decrease is evident in the three considered emergency departments and across all psychiatric diagnosis categories, and also concerns suicide attempts. This decrease is not specific to psychiatry: a greater than 50% decrease in daily total consultations was reported in the West China Hospital emergency,8 and similarly in England.9 Clearly, a fear of contamination in emergency departments has contributed to this. Moreover, unnecessary hospital emergency department visits may have decreased. In France, and elsewhere, recent decades have seen a significant increase in the number of emergency department consultations.10 This increase is contributed to by multiple complex factors, including a deterioration in accessibility of primary care services, leading to unnecessary visits. The treatment gap in psychiatry, the gap between experiencing a psychiatric disorder and using treatment services for this disorder, has already been described.7 Our results seem in line with this, given the significant increased proportion of consultations for psychotic disorders, and of hospitalizations without consent, coupled with the significant decrease in primary psychiatric consultations. For the most severe psychiatric disorders, emergency consultations are more necessary, and the decrease is less important. The development of telemedicine would also seem to have contributed to our results. The viability and feasibility of telemedicine consultations are likely to emerge subsequent to the COVID-19-triggered lockdown, possibly indicating a role for their sustained implementation. Finally, as some people may find new strengths and coping strategies during disasters, the current results may arise from an elevation in resilience capacity. Overall, despite the expectation of lockdown-induced stress increasing relapse risk across psychiatric conditions, the numbers of patients seeking emergency psychiatric consultations have decreased during lockdown. Clearly, COVID-19 has had an impact on psychiatric service utilization and will continue to do so,6 whilst also having possible implications for the nature of psychiatric service organization. The data are available on request. We want to thank Dr Yohann Dabi for his advice, Dr Andrei Szöke for his reviewing, and Dr George Anderson for his prompt editing work. No funding was secured for this study. The authors have declared that there are no conflicts of interest in relation to the subject of this study. Appendix S1 Supporting information. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

How do endogenous (voluntary) and exogenous (involuntary) attention modulate activity in visual cortex? Using ROI-based fMRI analysis, we measured fMRI activity for valid and invalid trials (target at cued/un-cued location, respectively), pre- or post-cueing endogenous or exogenous attention, while participants performed the same orientation discrimination task. We found stronger modulation in contralateral than ipsilateral visual regions, and higher activity in valid- than invalid-trials. For endogenous attention, modulation of stimulus-evoked activity due to a pre-cue increased along the visual hierarchy, but was constant due to a post-cue. For exogenous attention, modulation of stimulus-evoked activity due to a pre-cue was constant along the visual hierarchy, but was not modulated due to a post-cue. These findings reveal that endogenous and exogenous attention distinctly modulate activity in visuo-occipital areas during orienting and reorienting; endogenous attention facilitates both the encoding and the readout of visual information whereas exogenous attention only facilitates the encoding of information.

There are two non-mutually exclusive theories of individual variations in pro-capitalism opinions. The first theory views pro-capitalism opinions as self-serving: Individuals are opposed to market forces when they threaten their economic rents. The second theory views differences in such opinions as reflecting genuine disagreement on the efficiency of various economic systems. Using individual data, we investigate the validity of both theories, focusing on attitudes toward private ownership, private profit and competition. We find evidence that the first theory explains some of the variations in attitudes. However, consistent with the second theory, we also find evidence of individual learning about the comparative virtues of economic systems. The learning is slow, home-biased and path-dependent. Long-run cultural and historical determinants of pro-market attitudes, such as religion and legal origins, explain more than 40% of the cross-country variations in capitalism aversion. Last, we provide tentative evidence that at the country level, pro-market opinions affect the nature of economic institutions. Our results suggest that the feasibility of economic reform does not depend solely on its impact on the distribution of rents; ideological a-prioris are likely to be important as well. — Augustin Landier, David Thesmar and Mathias Thoenig

To the Editor: Over the past two decades, it has been demonstrated that brain mapping in an awake patient is a very reliable tool for brain tumor resection, allowing us to maximize the extent of resection while minimizing the functional risk.1 This methodology is becoming more and more popular, and different teams have introduced many new tasks in their intraoperative battery, for motor functions2 as well as for cognitive functions.3,4 While the aim of preserving functions better and better cannot be blamed, it should be kept in mind that selecting for each case a personalized minimal set of tasks is crucial: the awake surgery team has to find an optimal trade-off between the number of tasks incorporated in the intraoperative battery and the limited amount of time of the awake period (about 2 h, in keeping with the onset of the patient's tiredness, which renders monitoring unreliable). More than that, there is a risk of introducing tasks that would be too sensitive, in the sense that the removal of a positive site would not necessarily lead to a permanent deficit of the function, meaning that brain mapping would restrict the extent of resection for no good reasons. We, thus, would like to highlight in this letter that the introduction of a new task tapping a specific sensorimotor, cognitive, or emotional process should follow a strict scientific plan. First, it needs to be demonstrated in a retrospective series of patients operated on without any intraoperative monitoring of the task that some of them do indeed suffer from a permanent deficit of the cognitive function at hand. By permanent deficit, we mean a score decrease of 1.5 SD or more at 1 yr after surgery, despite patients benefitting from a targeted rehabilitation program in the postoperative period. Time and training are indeed the two parameters underlying an optimal efficiency of brain plasticity implementation. One or both of the conditions were not met in several recent studies. For example, in the study of Martino et al,5 only 50% of patients were entered in a rehabilitation program, potentially contributing to lessen the degree of recovery of verbal short-term memory, and likely explaining the discrepancy with the study of Teixidor et al.6 Another example is given by a recent study about deficits in spatial working memory,7 in which the chronicity was defined at 1 mo postop, which is too early in the process of recovery. Of note, an analysis of intrapatient changes should be preferred to a group-level analysis. For example, this might explain the discrepancy in the study of Herbet et al8 and the one of Nakajima et al9 regarding the long-term deficits in high-level mentalizing. Once it has been established that some patients do suffer permanent deficits, one needs to determine which part of the resected brain and/or which part of the brain still infiltrated by a residual tumor correlates with the persistent impairment. Again, this is important, as using widely the new task for any location could lead to prematurely stop the resection because of the intraoperative response to electrical stimulation, whereas the function would have recovered in the long term, after an acute period of impairment (the so-called “false positives”10). For example, before introducing intraoperatively the Read the Mind in the Eye test for right-sided frontal tumors,11 Herbet et al8 first demonstrated that resections in the right posterior inferior frontal gyrus were associated with long-term deficits in a subset of patients. Finally, definitive evidence should be given by comparing the cognitive scores of 2 consecutive cohorts, one operated on with task monitoring and one without. Very few studies complied with this requirement. This has been done in a recent study looking at executive function testing during right frontal resections: outcomes were much better in the group in which the Stroop task was monitored compared to the control group.12 In the same vein, Mandonnet et al13 first reported a strong deficit in cognitive flexibility after a right parietal glioma resection and determined how this deficit was caused by a wide disconnection within the associative fibers of the cognitive control network. Then, they demonstrated in a second patient-case with a tumor at a similar location that the stimulation of the white matter in the right parieto-temporal junction disrupted intraoperatively the part B of the trail making test, prompting the surgeon to stop the resection and allowing to preserve cognitive flexibility.14 Last but not least, and although this does not constitute a proof by itself, the fact that several teams adopt a new task is a good indicator of its interest and reproducibility. Hence, several groups have confirmed the usefulness of line bisection,15,16 nonverbal semantic association,16-19 or mentalization tasks,9 following the seminal reports introducing these new tasks.20-22 We, thus, advocate to analyze in a systematic manner the level of evidence before introducing a new intraoperative task. This would help better delineate the situations in which mapping is performed for patient care from situations in which mapping is motivated by a scientific quest. For example, additional tasks, such as a 2-back verbal memory task, have been sometimes introduced into the operating theater, with an identification of structures eliciting disturbances of verbal working memory during electrical mapping, and with, nonetheless, a surgical resection of these structures despite a positive mapping23: therefore, the task was useless for the patient, and was tested only for research purposes. Not to say that new tasks should never be tested only for research, but in this latter case, the patient should be clearly informed and should agree with the purely exploratory nature of this new task monitoring. Disclosures The authors have no personal, financial, or institutional interest in any of the drugs, materials, or devices described in this article.

Separation logic is a well-known assertion language for Hoare-style proof systems. We show that first-order separation logic with a unique record field restricted to two quantified variables and no program variables is undecidable. This is among the smallest fragments of separation logic known to be undecidable, and this contrasts with the decidability of two-variable first-order logic. We also investigate its restriction by dropping the magic wand connective, known to be decidable with nonelementary complexity, and we show that the satisfiability problem with only two quantified variables is not yet elementary recursive. Furthermore, we establish insightful and concrete relationships between two-variable separation logic and propositional interval temporal logic (PITL), data logics, and modal logics, providing an inner circle of closely related logics.

Keloid scars are hypertrophic and proliferating pathological scars extending beyond the initial lesion and without tendency to regression. Usually, keloids are considered and treated as a single entity but clinical observations suggest heterogeneity in keloid morphologies with distinction of superficial/extensive and nodular entities. Within a keloid, heterogeneity could also be detected between superficial and deep dermis or centre and periphery. Focusing on fibroblasts as main actors of keloid formation, we aimed at evaluating intra- and inter-keloid fibroblast heterogeneity by analysing their gene expression and functional capacities (proliferation, migration, traction forces), in order to improve our understanding of keloid pathogenesis. Fibroblasts were obtained from centre, periphery, papillary and reticular dermis from extensive or nodular keloids and were compared to control fibroblasts from healthy skin. Transcriptional profiling of fibroblasts identified a total of 834 differentially expressed genes between nodular and extensive keloids. Quantification of ECM-associated gene expression by RT-qPCR brought evidence that central reticular fibroblasts of nodular keloids are the population which synthesize higher levels of mature collagens, TGFβ, HIF1α and αSMA as compared to control skin, suggesting that this central deep region is the nucleus of ECM production with a centrifuge extension in keloids. Although no significant variations were found for basal proliferation, migration of peripheral fibroblasts from extensive keloids was higher than that of central ones and from nodular cells. Moreover, these peripheral fibroblasts from extensive keloids exhibited higher traction forces than central cells, control fibroblasts and nodular ones. Altogether, studying fibroblast features demonstrate keloid heterogeneity, leading to a better understanding of keloid pathophysiology and treatment adaptation.

We show that first-order separation logic with one record field restricted to two variables and the separating implication (no separating conjunction) is as expressive as weak second-order logic, substantially sharpening a previous result. Capturing weak second-order logic with such a restricted form of separation logic requires substantial updates to known proof techniques. We develop these, and as a by-product identify the smallest fragment of separation logic known to be undecidable: first-order separation logic with one record field, two variables, and no separating conjunction.

Background The diet impact on cardiovascular diseases has been investigated widely, but the association between dietary patterns (DPs) and subclinical cardiovascular damage remains unclear. More informative DPs could be provided by considering metabolic syndrome components as intermediate markers. This study aimed to identify DPs according to generation and sex using reduced-rank regression (RRR) with metabolic syndrome components as intermediate markers and assess their associations with intima-media thickness, left ventricular mass, and carotid-femoral pulse-wave velocity in an initially healthy population-based family study. Methods and Results This study included 1527 participants from the STANISLAS (Suivi Temporaire Annuel Non-Invasif de la Santé des Lorrains Assurés Sociaux) cohort fourth examination. DPs were derived using reduced-rank regression according to generation (G1: age ≥50 years; G2: age <50 years) and sex. Associations between DPs and cardiovascular damage were analyzed using multivariable linear regression models. Although identified DPs were correlated between generations and sex, qualitative differences were observed: whereas only unhealthy DPs were found for both men generations, healthy DPs were identified in G2 ("fruity desserts") and G1 ("fiber and w3 oil") women. The "alcohol," "fast food and alcohol," "fried, processed, and dairy products," and "meat, starch, sodas, and fat" DPs in G1 and G2 men and in G1 and G2 women, respectively, were associated with high left ventricular mass (β [95% CI], 0.23 [0.10-0.36], 0.76 [0.00-1.52], 1.71 [0.16-3.26], and 1.80 [0.45-3.14]). The "alcohol" DP in G1 men was positively associated with carotid-femoral pulse-wave velocity (0.22 [0.09-0.34]). Conclusions The DPs that explain the maximum variation in metabolic syndrome components had different associations with subclinical cardiovascular damage across generation and sex. Our results indicate that dietary recommendations should be tailored according to age and sex. Clinical Trial Registration URL: http://www.clinicaltrials.gov. Unique identifier: NCT01391442.

We present SIDE, a Semantic Integrated Development Environment. SIDE uses static analysis to enrich existing IDE features and also adds new features. It augments the way existing compilers find syntactic errors - in real time, as the programmer is writing code without execution - by also finding semantic errors, e.g., arithmetic expressions that may overflow. If it finds an error, it suggests a repair in the form of code - e.g., providing an equivalent yet non-overflowing expression. Repairs are correct by construction. SIDE also enhances code refactoring (by suggesting precise yet general contracts), code review (by answering what-if questions), and code searching (by answering questions like "find all the callers where x < y").

No abstract available for this article.

Preterm birth can significantly impact cognitive development, particularly executive functions (EF). This study investigated hot (with emotional/motivational aspects) and cool (purely neutral/cognitive) EF trajectories in preterm and full-term children, examining brain-behavior relationships. It included 3508 participants aged 9-10 years (mean age 10.0 years) at baseline from the Adolescent Brain and Cognitive Development (ABCD®) study, evenly split between preterm and full-term births (54.36 % males; 1.05 % Asian American, 10.69 % Black, 15.68 % Hispanic, 61.57 % White, 11.09 % other). Participants were followed for 4 years, completing MRI scans and a cool EF task at baseline and at the 2-year follow-up, as well as hot/cool and hot EF tasks at the 1- and 3-year follow-ups. Linear mixed models showed varying effects of preterm birth across the different EF tasks. Specifically, preterm children showed persistent cool EF deficits and a catch-up pattern for hot EF, while performance on the hot/cool task showed no association with preterm birth. Brain-behavior bivariate latent change score analyses identified distinct bidirectional relationships in specific regions, suggesting altered cognitive-brain maturation interactions in preterm children. These findings highlight the complex nature of EF development following preterm birth: while cool EF deficits persist, hot EF shows catch-up growth in preterm children during early adolescence. This emphasizes the need for tailored interventions and long-term follow-up in this population.

OBJECTIVES: Sustained virological response (SVR) decreases the risk of hepatitis C virus (HCV)-related events. Nevertheless, a substantial risk of events persists. We estimated incidences and identified factors associated with severe clinical events after SVR following treatment with a direct-acting antiviral (DAA) in HIV/HCV-coinfected patients. METHODS: Participants from the ANRS CO13 HEPAVIH were included if they reached SVR. Incidence rates of overall mortality, liver-related events, AIDS-defining events, ischaemic events and non-liver non-AIDS-defining cancers (NLNA) were estimated. Factors associated with the risk of those events were identified using Poisson models adjusted on age at SVR and sex. RESULTS: In all, 775 participants were included. Incidence rates (95% confidence interval) of liver-related events, overall mortality, AIDS-defining events, ischaemic events and NLNA cancers per 1000 person-years were 5.9 (3.3-10.3), 22.2 (16.8-29.5), 0.6 (0.1-4.5), 7.3 (4.4-12.2) and 13.7 (9.4-20.0), respectively. For all events, incidence rates were higher in cirrhotic than in non-cirrhotic participants. Cirrhosis, liver stiffness and CD4 count were associated with liver-related events. Factors associated with overall mortality were age, cirrhosis, liver stiffness and gamma-glutamyl transferase (GGT). For ischaemic events and NLNA cancers, associated factors were total cholesterol and CD4 count, respectively. CONCLUSIONS: After SVR following a DAA treatment, liver-related and AIDS-defining events were observed less frequently than NLNA cancers. Severity of liver disease was associated with the risk of liver-related events and of overall mortality but not with ischaemic events and NLNA cancers. Factors reflecting HIV infection were associated with NLNA cancers and liver-related events.

Cognitive remediation therapy interventions could improve cognitive functioning in subjects with autism. To investigate the benefit of a short cognitive training rehabilitation in children with autism spectrum disorder (ASD) on pursuit and fixation performances. We recruited two groups (G1 and G2) of 30 children with ASD, sex-, IQ- and age-matched (mean 11.6 ± 0.5 years), and pursuit and fixation eye movements were recorded twice at T1 and T2. Between T1 and T2, a 10-min cognitive training was performed by the G1 group only, whereas the G2 group had a 10-min of rest. For all children with ASD enrolled in the study, there was a positive correlation between restricted and repetitive behaviour scores of both Autism Diagnostic Interview-Revised (ADI-R) and the Autism Diagnostic Observation Schedule (ADOS) and the number of saccades recorded during the fixation task at T1. At T1, oculomotor performances were similar for both groups of ASD children (G1 and G2). At T2, we observed a significant reduction in the number of saccades made during both pursuit and fixation tasks. Our findings underlined the importance to promote cognitive training rehabilitation for children with ASD, leading to a better performance in inhibitory and attention functioning responsible for pursuit and fixation eye movement's performance.

Background: The COVID-19 pandemic presented families with novel challenges. Mothers were at particular risk for parental burnout, however, there is limited research on self-care behaviors to ameliorate it explicitly for mothers of young children (aged 3 and younger). Moreover, there has been little in-depth analysis on barriers to self-care and how mothers realistically implement it in their lives. Methods: In this article, we explore influences on and barriers to self-care in mothers of young children during the COVID-19 pandemic. Using a content analysis approach, we used verbal testimony from mothers to create a coding framework and applied that framework to the sample ( N = 717). Results: Qualitative analyses revealed that beauty and personal care were the most utilized self-care acts. Two major barriers were lack of childcare and limited time. Social support was the most frequently reported asset to engaging in self-care. Participants noted that the pandemic significantly restricted their access to activities and social support. Conclusions: These findings emphasize the need to encourage mothers to prioritize self-care and incorporate their support systems to facilitate engagement. These results can inform programming to increase self-care behaviors in mothers, particularly during times of high environmental stressors. Future research should examine how resources can be allocated toward barriers of self-care to reduce burnout and improve quality of life.

Abstract Natural language appears to allow the ascription of properties of numeral symbols to the denotation of number referring phrases. The paper describes the phenomenon and presents two alternative explanations for why it obtains. One combining an intuitive semantics for number referring phrases and a predicate-shifting mechanism, the other assigning number referring phrases a structured denotation consisting of two parts: a mathematical object (the number) and a contextually determined numeral symbol. Some preliminary observations in favor of the second analysis are offered.

In this paper, we show that native speakers spontaneously divide the complex meaning of a new word into a presuppositional component and an assertive component. These results argue for the existence of a productive triggering algorithm for presuppositions, one that is not based on alternative lexical items nor on contextual salience. On a methodological level, the proposed learning paradigm can be used to test further theories concerned with the interaction of lexical properties and conceptual biases.

Many sentences can be interpreted both as a metaphor and as a literal claim, depending on the context. The aim of this paper is to show that there are discourse-based systematic constraints on the identification of an utterance as metaphorical, literal, or both (as in the case of twice-apt metaphors), from a normative point of view. We claim that the key is contextual coherence. In order to substantiate this claim, we introduce a novel notion of context as a rich and heterogeneous body of information, including previous discourse, elements coming from the surroundings of the utterance, background information, and Questions Under Discussion (QUD) issued from these three sources. We then define contextual coherence as a relation between what we call the minimal paraphrase of the metaphor and the context, and argue that for an interpretation to be coherent two conditions must be met. First, the minimal paraphrase must address some question in the QUD stack. Second, it must be externally consistent, i.e. consistent with the available contextual information. Finally, we argue that an approach based on contextual coherence is better suited to deal with twice-true and twice-apt metaphors than traditional approaches based on semantic deviance or pragmatic lack of fit.