Mitral Annular Disjunction in the Context of Mitral Valve Prolapse: Identifying the At-Risk Patient

Mitral annular disjunction (MAD), a separation between the left atrium/mitral valve annulus and the left ventricular myocardium, is frequently seen in patients with arrhythmic mitral valve prolapse. Although an association exists between MAD and ventricular arrhythmias, little is known regarding the identification of individuals at high risk. Multimodality imaging including echocardiography, computed tomography, cardiac magnetic resonance, and positron emission tomography can play an important role in both the diagnosis and risk stratification of MAD. Due to a paucity of data, clinical decision making in a patient with MAD is challenging and remains largely empirical. Although MAD itself can be corrected surgically, the prevention and treatment of associated arrhythmias may require medical therapy, catheter ablation, and an implantable cardioverter-defibrillator. Prospective data are required to define the role of implantable cardioverter-defibrillators, targeted catheter ablation, and surgical correction in selected, at-risk patients.

Phylogenetics and phylogeography of Euphorbia canariensis reveal an extreme Canarian-Asian disjunction but limited inter-island colonization

Euphorbia canariensis is an iconic endemic species representative of the lowland xerophytic communities of the Canary Islands. It is widely distributed in the archipelago despite having diasporas unspecialized for long-distance dispersal. Here, we reconstructed the evolutionary history of E. canariensis at two levels: a time-calibrated phylogenetic analysis aimed at clarifying interspecific relationships and large-scale biogeographic patterns; and a phylogeographic study focused on the history of colonization across the Canary Islands. For the phylogenetic study, we sequenced the ITS region for E. canariensis and related species of Euphorbia sect. Euphorbia. For the phylogeographic study, we sequenced two cpDNA regions for 28 populations representing the distribution range of E. canariensis. The number of inter-island colonization events was explored using PAICE, a recently developed method that includes a sample size correction. Additionally, we used species distribution modelling (SDM) to evaluate environmental suitability for E. canariensis through time. Phylogenetic results supported a close relationship between E. canariensis and certain Southeast Asian species (E. epiphylloides, E. lacei, E. sessiliflora). In the Canaries, E. canariensis displayed a west-to-east colonization pattern, not conforming to the "progression rule", i.e. the concordance between phylogeographic patterns and island emergence times. We estimated between 20 and 50 inter-island colonization events, all of them in the Quaternary, and SDM suggested a late Quaternary increase in environmental suitability for E. canariensis. The extreme biogeographic disjunction between Macaronesia and Southeast Asia (ca. 11,000 km) parallels that found in a few other genera (Pinus, Dracaena). We hypothesize that these disjunctions are better explained by extinction across north Africa and southwest Asia rather than long-distance dispersal. The relatively low number of inter-island colonization events across the Canaries is congruent with the low dispersal capabilities of E. canariensis.

The scope and role of deduction in infant cognition

The origins of the human capacity for logically structured thought are still a mystery. Studies on young humans, which can be particularly informative, present conflicting results. Infants seem able to generate competing hypotheses1,2,3 and monitor the certainty or probability of one-shot outcomes,4,5,6,7,8 suggesting the existence of an articulated language of thought.9 However, sometimes toddlers10 and even children younger than 411,12,13,14 fail tasks seemingly requiring the same representational abilities. One fundamental test for the presence of logical abilities is the concept of disjunction as a way into the conception of alternative possibilities, and of disjunctive elimination as a way to prune them. Here, we document their widespread presence in 19-month-old infants. In a word-referent association task, both bilingual and monolingual infants display a pattern of oculomotor inspection previously found to be a hallmark of disjunctive reasoning in adults and children,15,16 showing that the onset of logical reasoning is not crucially dependent on language experience. The pattern appears when targets are novel, but also when both objects and words are known, though likely not yet sedimented into a mature lexicon. Disjunctive reasoning also surfaces in a non-linguistic location search task, not prompted by violated expectations, showing that infants reason by elimination spontaneously. Together, these results help answer long-standing empirical and philosophical puzzles about the role of logic in early knowledge development, suggesting that by increasing confidence in some options while eliminating alternatives, logic provides scaffolding for the organization of knowledge about the world, language, and language-world relations.

Phylogeography and genetic variation in Western Jacob's ladder (Polemonium occidentale) provide insights into the origin and conservation of rare species in the Great Lakes region

The perennial herb Western Jacob's Ladder (Polemonium occidentale, Polemoniaceae) is widespread in the mountains of western North America but reappears as a disjunct in the Great Lakes Region in Minnesota and Wisconsin, USA as the narrow endemic P. occidentale subsp. lacustre. This distribution is shown by a diverse assemblage of angiosperms. It has been hypothesized that these species became isolated just after the Last Glacial Maximum, but this has not been tested. Additionally, the genetic diversity and population connectivity of the endemic Great Lakes flora has been understudied, with important conservation implications. Using genotyping-by-sequencing, we examined the relationship of P. occidentale subsp. lacustre to its closest relatives, relationships among all known populations, and genetic diversity within these populations. Polemonium occidentale subsp. lacustre represents an isolated, unique lineage that diverged from its closest relatives 1.3 Ma and arrived in the Great Lakes Region by at least 38 ka. Nearly all extant populations diverged prior to the Last Glacial Maximum, are genetically distinct, and show little within-population genetic diversity. Clonality may mitigate reduction in diversity due to drift. Mixed population signal between Wisconsin and some Minnesota populations may be due to gene flow during the Late Pleistocene. While populations of P. occidentale subsp. lacustre may be relictual from a now extinct western relative, it is best treated as a distinct species. Conservation efforts should focus more on ensuring that current populations remain rather than maintaining large populations sizes across a few populations. However, encouraging habitat heterogeneity may accomplish both simultaneously.

Uniloculares Based on Plastid Genome Analysis

Scientists have long been captivated by biogeographic disjunctions, and disjunctions between East Asia and North America have been particularly well-studied at the genus and family levels. By contrast, disjunctions between eastern and western Asia have received less attention. Euonymus L. is taxonomically divided into two sections based on the number of cells in anthers as follows: E. sect. Uniloculares has one-celled anthers and occurs mainly in Asia, whereas E. sect. Biloculares has two-celled anthers and is distributed globally. We used Illumina sequencing to investigate the genomes of four species in sect. Uniloculares. The chloroplast (cp) genomes are highly conserved (157,290-158,094 bp). Pseudogenisation of ndhF and intron loss in rps16 was detected. Based on the cp genomes of the four species of E. sect. Uniloculares, we propose a novel hypothesis of disjunction between eastern and western Asia. Biogeographic reconstruction and molecular dating revealed that sect. Uniloculares separated from its sect. Biloculares forebears 4.0 Mya during the Pliocene era. The radial diversification of sect. Uniloculares from East Asia and the establishment of the western Asian clade during the Pleistocene era (1.9 Mya) were the results of both dispersal and vicariance, making the section the youngest diverged clade conforming to age estimation. The centre of origin of sect. Uniloculares was determined to be in East Asia. Disjunctions and diversification between eastern and western Asia in sect. Uniloculares are thought to have been caused by changes in monsoon patterns, temperature variations, and the emergence of the Gobi Desert.

An Evolutionary Study of Carex Subg. Psyllophorae (Cyperaceae) Sheds Light on a Strikingly Disjunct Distribution in the Southern Hemisphere, With Emphasis on Its Patagonian Diversification

Carex subgenus Psyllophorae is an engaging study group due to its early diversification compared to most Carex lineages, and its remarkable disjunct distribution in four continents corresponding to three independent sections: sect. Psyllophorae in Western Palearctic, sect. Schoenoxiphium in Afrotropical region, and sect. Junciformes in South America (SA) and SW Pacific. The latter section is mainly distributed in Patagonia and the Andes, where it is one of the few Carex groups with a significant in situ diversification. We assess the role of historical geo-climatic events in the evolutionary history of the group, particularly intercontinental colonization events and diversification processes, with an emphasis on SA. We performed an integrative study using phylogenetic (four DNA regions), divergence times, diversification rates, biogeographic reconstruction, and bioclimatic niche evolution analyses. The crown age of subg. Psyllophorae (early Miocene) supports this lineage as one of the oldest within Carex. The diversification rate probably decreased over time in the whole subgenus. Geography seems to have played a primary role in the diversification of subg. Psyllophorae. Inferred divergence times imply a diversification scenario away from primary Gondwanan vicariance hypotheses and suggest long-distance dispersal-mediated allopatric diversification. Section Junciformes remained in Northern Patagonia since its divergence until Plio-Pleistocene glaciations. Andean orogeny appears to have acted as a northward corridor, which contrasts with the general pattern of North-to-South migration for temperate-adapted organisms. A striking niche conservatism characterizes the evolution of this section. Colonization of the SW Pacific took place on a single long-distance dispersal event from SA. The little ecological changes involved in the trans-Pacific disjunction imply the preadaptation of the group prior to the colonization of the SW Pacific. The high species number of the section results from simple accumulation of morphological changes (disparification), rather than shifts in ecological niche related to increased diversification rates (radiation).

Do Monkeys and Young Children Understand Exclusive "Or" Relations? A Commentary on Ferrigno et al. (2021)

Ferrigno et al. (2021) claim to provide evidence that monkeys can reason through the disjunctive syllogism (given A or B, not A, therefore B) and conclude that monkeys therefore understand logical "or" relations. Yet their data fail to provide evidence that the baboons they tested understood the exclusive "or" relations in the experimental task. For two mutually exclusive possibilities-A or B-the monkeys appeared to infer that B was true when A was shown to be false, but they failed to infer that B was false when A was shown to be true. In our own research, we recently found an identical response pattern in 2.5- to 4-year-old children, whereas 5-year-olds demonstrated that they could make both inferences. The monkeys' and younger children's responses are instead consistent with an incorrect understanding of A and B as having an inclusive "or" relation. Only the older children provided compelling evidence of representing the exclusive "or" relation between A and B.

The Interpretation of Disjunction in the Scope of Dou in Child Mandarin

A recent theory provides a unified cross-linguistic analysis of the interpretations that are assigned to expressions for disjunction, Negative Polarity Items, Free Choice Items, and the non-interrogative uses of wh-phrases in languages such as Mandarin Chinese. If this approach is on the right track, children should be expected to demonstrate similar patterns in the acquisition of these linguistic expressions. Previous research has found that, by age four, children have acquired the knowledge that both the existential indefinite renhe “any” and wh-words in Mandarin Chinese are interpreted as Negative Polarity Items when they are bound by downward entailing operators, but the same expressions are interpreted as Free Choice Items (with a conjunctive interpretation) when they are bound by deontic modals (Mandarin keyi) or by the Mandarin adverbial quantifier dou “all”. The present study extends this line of research to the Mandarin disjunction word huozhe. A Truth Value Judgment Task was used to investigate the possibility that disjunction phrases that are bound by the adverbial quantifier dou generate a conjunctive interpretation in the grammars of Mandarin-speaking 4-year-old children. The findings confirmed this prediction. We discuss the implications of the findings for linguistic theory and for language learnability.

Negation and Free Choice Inference in Child Mandarin

In sentences with internal negation, Free Choice Inferences (FCIs) are canceled (Chierchia, 2013). The present study investigated the possibility that FCIs are negated, not canceled, by external negation. In previous research, both Mandarin-speaking children and adults were found to license FCIs in affirmative sentences with a modal verb and the disjunction word huozhe ‘or’ (Zhou et al., 2013). The present study contrasted internal versus external negation in sentences that contained all the ingredients needed to license FCIs. Four experiments were conducted using the Truth Value Judgment Task (Crain and Thornton, 1998). Experiment 1 tested Mandarin-speaking children and adults using sentences with internal negation, a modal verb and disjunction. As expected, children did not license FCIs; rather, they assigned a ‘neither’ interpretation to disjunction. Also as expected, adults analyzed disjunction as taking scope over internal negation, yielding a ‘not both’ interpretation (Jing et al., 2005). Experiment 1 provided the benchmarks for sentences with external negation in Experiments 2-4. Experiment 2 confirmed that English-speaking adults distinguish between internal and external negation in sentences with disjunction. In Experiment 3, external negation was conveyed by the focus adverb zhiyou ‘only’. External negation eliminated the between-group differences observed in Experiment 1. Both children and adults analyzed external negation as taking scope over disjunction. Experiment 4 tested the effect of external negation on the computation of FCIs. The test sentences only differed from Experiment 1 by using external negation, rather than internal negation. Again, children and adults interpreted the test sentences in the same way. Most importantly, in contrast to Experiment 1 (with internal negation), both groups analyzed external negation as negating, rather than canceling, FCIs. The findings support the distinction between internal and external negation.

An account of subjective probability judgment for joint events: Conjunctive and disjunctive

Probability judgment is a vital part of many aspects of everyday life. In the present paper, we present a new theory of the way in which individuals produce probability estimates for joint events: conjunctive and disjunctive. We propose that a majority of individuals produce conjunctive (disjunctive) estimates by making a quasi-random adjustment, positive or negative, from the less (more) likely component probability with the other component playing no obvious role. In two studies, we produce evidence supporting propositions that follow from our theory. First, the component probabilities do appear to play the distinct roles we propose in determining the joint event probabilities. Second, contrary to probability theory and other accounts of probability judgment, we show that the conjunctive-less likely probability difference is unrelated to the more likely disjunctive probability difference (in normative theory these quantities are identical). In conclusion, while violating the norms of probability judgment, we argue that estimates produced in the manner we propose will be close enough to the normative values especially given the changing nature of the external environment and the incomplete nature of available information.

Scalar and Ignorance Inferences Are Both Computed Immediately upon Encountering the Sentential Connective: The Online Processing of Sentences with Disjunction Using the Visual World Paradigm

Accounts based on the pragmatic maxim of quantity make different predictions about the computation of scalar versus ignorance inferences. These different predictions are evaluated in two eye-tracking experiments using a visual world paradigm to assess the on-line computation of inferences. The test sentences contained disjunction phrases, which engender both kinds of inferences. The first experiment documented that both inferences are computed immediately upon encountering the disjunctive connective, at nearly identical temporal locations. The second experiment was designed to determine whether or not there exists an intermediate stage at which the truth of the corresponding conjunction phrase is ignored. No such stage was found.

Ecological range shift in the polyploid members of the South American genus Fosterella (Bromeliaceae)

Background and Aims

The distribution of polyploidy along a relatively steep Andean elevation and climatic gradient is studied using the genus Fosterella L.B. Sm. (Bromeliaceae) as a model system. Ecological differentiation of cytotypes and the link of polyploidy with historical biogeographic processes such as dispersal events and range shift are assessed.

Methods

4',6-Diamidino-2-phenylindole (DAPI) staining of nuclei and flow cytometry were used to estimate the ploidy levels of 159 plants from 22 species sampled throughout the distribution range of the genus. Ecological differentiation among ploidy levels was tested by comparing the sets of climatic variables. Ancestral chromosome number reconstruction was carried out on the basis of a previously generated phylogeographic framework.

Key Results

This study represents the first assessment of intrageneric, intraspecific and partially intrapopulational cytotype diversity in a genus of the Bromeliaceae family. In Fosterella , the occurrence of polyploidy was limited to the phylogenetically isolated penduliflora and rusbyi groups. Cytotypes were found to be ecologically differentiated, showing that polyploids preferentially occupy colder habitats with high annual temperature variability (seasonality). The combined effects of biogeographic history and adaptive processes are presumed to have shaped the current cytotype distribution in the genus.

Conclusions

The results provide indirect evidence for both adaptive ecological and non-adaptive historical processes that jointly influenced the cytotype distribution in the predominantly Andean genus Fosterella (Bromeliaceae). The results also exemplify the role of polyploidy as an important driver of speciation in a topographically highly structured and thus climatically diverse landscape.

Evaluation of the epistemic state of the speaker/author

Language users are sensitive to their language's grammatical requirements, the plausibility of the situation described and the information shared by speaker and listener. We propose that they are also sensitive to whether an author is likely to be in a state of knowledge that actually supports the assertion being made. Failure to be in such a state reduces the naturalness of the assertion. Consistent with this proposal, sentences with a disjoined noun phrase are judged to be less natural than their conjunctive counterparts, presumably because the author of a disjunctive sentence must know that an event took place but not know which of the two individuals was the agent. This unlikely state of knowledge reduces the naturalness of the sentence. The results of three experiments indicate that providing evidence that the speaker could be in an unlikely epistemic state reduces the disjunction penalty; a fourth extends the demonstration of the penalty from coordinated noun phrases to coordinated verb phrases. We also present one experiment that explores the possibility that disjunction penalty is due to the unexpectedness of a disjunction. These findings demonstrate that language users evaluate linguistic input in light of the epistemic state of its author.

C-Command in the Grammars of Children with High Functioning Autism

A recent study questioned the adherence of children with Autism Spectrum Disorders (ASD) to a linguistic constraint on the use of reflexive pronouns (Principle A) in sentences like Bart's dad is touching himself. This led researchers to question whether children with ASD are able to compute the hierarchical structural relationship of c-command, and raised the possibility that the children rely on a linear strategy for reference assignment. The current study investigates the status of c-command in children with ASD by testing their interpretation of sentences like (1) and (2) that tease apart use of c-command and a linear strategy for reference assignment.

The girl who stayed up late will not get a dime or a jewel (C-command)

The girl who didn't go to sleep will get a dime or a jewel (Non C-command)

These examples both contain negation (not or didn't) and disjunction (or). In (1), negation c-commands the disjunction phrase, yielding a conjunctive entailment. This gives rise to the meaning that the girl who stayed up late won't get a dime and she won't get a jewel. In (2), negation is positioned inside a relative clause and it does not c-command disjunction. Therefore, no conjunctive entailment follows. Thus, (2) is true if the girl just gets a dime or just a jewel, or possibly both. If children with ASD lack c-command, then (1) will not give rise to a conjunctive entailment. In this case, children might rely on a linear strategy for reference assignment. Since negation precedes disjunction in both (1) and (2), they might be interpreted in a similar manner. Likewise, children who show knowledge of c-command should perform well on sentences governed by Principle A. These hypotheses were tested in experiments with 12 Australian children with HFA, aged 5;4 to 12;7, and 12 typically-developing controls, matched on non-verbal IQ. There was no significant difference in the pattern of responses by children with HFA and the control children on either (1) and (2) or the Principle A sentences. The findings provide preliminary support for the proposal that knowledge of c-command and Principle A is intact in HFA children.

Evolution along the Great Rift Valley: phenotypic and genetic differentiation of East African white-eyes (Aves, Zosteropidae)

The moist and cool cloud forests of East Africa represent a network of isolated habitats that are separated by dry and warm lowland savannah, offering an opportunity to investigate how strikingly different selective regimes affect species diversification. Here, we used the passerine genus Zosterops (white-eyes) from this region as our model system. Species of the genus occur in contrasting distribution settings, with geographical mountain isolation driving diversification, and savannah interconnectivity preventing differentiation. We analyze (1) patterns of phenotypic and genetic differentiation in high- and lowland species (different distribution settings), (2) investigate the potential effects of natural selection and temporal and spatial isolation (evolutionary drivers), and (3) critically review the taxonomy of this species complex. We found strong phenotypic and genetic differentiation among and within the three focal species, both in the highland species complex and in the lowland taxa. Altitude was a stronger predictor of phenotypic patterns than the current taxonomic classification. We found longitudinal and latitudinal phenotypic gradients for all three species. Furthermore, wing length and body weight were significantly correlated with altitude and habitat type in the highland species Z. poliogaster. Genetic and phenotypic divergence showed contrasting inter- and intraspecific structures. We suggest that the evolution of phenotypic characters is mainly driven by natural selection due to differences in the two macro-habitats, cloud forest and savannah. In contrast, patterns of neutral genetic variation appear to be rather driven by geographical isolation of the respective mountain massifs. Populations of the Z. poliogaster complex, as well as Z. senegalensis and Z. abyssinicus, are not monophyletic based on microsatellite data and have higher levels of intraspecific differentiation compared to the currently accepted species.

Thirteen new records of ferns from Brazil

Thirteen fern species are reported for the first time for Brazil. Among the new records, eight are from Acre state (Cyatheasubincisa, Cyclodiumtrianae, Elaphoglossumstenophyllum, Hypoderrisbrauniana, Pleopeltisstolzei, Thelypterisarcana, Thelypteriscomosa, Thelypterisvaldepilosa), two are from Pará state (Polypodiumflagellare, Tectariaheracleifolia), one from Minas Gerais state (Alsophilasalvinii), one from Ceará state (Campyloneurumcostatum) and one from Bahia state (Thelypterisrolandii). Part of the species shows a disjunct occurrence or illustrates floristic relations between Brazilian and Andean Mountains or Central American Mountains.

Out of the alps: the biogeography of a disjunctly distributed mountain butterfly, the almond-eyed ringlet Erebia alberganus (Lepidoptera, Satyrinae)

Many studies on the biogeography of thermophilic and arctic-alpine species were performed during the past. Only little is known about species with intermediate characteristics. We analyzed the molecular biogeography of the butterfly Erebia alberganus (30 populations, representing 1106 individuals), sampled over the Alps, Apennines (Italy), and the Stara Planina (Bulgaria) using allozyme electrophoresis (17 loci). Genetic analyses revealed 3 major splits, with the strongest between the Stara Planina populations and all other populations, and a weaker split between the Alps and the Apennines. Individuals from the Apennines were genetically nested within the Alps group. The Alps cluster was segregated into 3 groups: the Southwestern, Western/Central, and Eastern Alps. The genetic diversities were highest for the Alps populations and significantly lower in the 2 isolates (Apennines, Stara Planina). The remarkable genetic split between Stara Planina and all other populations and the genetic distinctiveness of the former cluster might be interpreted as an ancient colonization event of this Balkan mountain range. The Apennines populations derive from a more recent expansion out of the Southwestern Alps. After surviving the Würm ice age most probably in the central Apennines, accompanied by genetic modification of some of these populations, northward expansion might have started from the western parts of the central Apennines reaching the northern Apennines during the early postglacial. The subtle genetic differentiation found among the Alps populations probably reflects 3 geographically disjunct Würm glacial centers located at the western slopes of the Southwestern Alps, at the southern slopes of the Central Alps, and in the Southeastern Alps.

Out of the Neotropics: Late Cretaceous colonization of Australasia by American arthropods

The origins of tropical southwest Pacific diversity are traditionally attributed to southeast Asia or Australia. Oceanic and fragment islands are typically colonized by lineages from adjacent continental margins, resulting in attrition of diversity with distance from the mainland. Here, we show that an exceptional tropical family of harvestmen with a trans-Pacific disjunct distribution has its origin in the Neotropics. We found in a multi-locus phylogenetic analysis that the opilionid family Zalmoxidae, which is distributed in tropical forests on both sides of the Pacific, is a monophyletic entity with basal lineages endemic to Amazonia and Mesoamerica. Indo-Pacific Zalmoxidae constitute a nested clade, indicating a single colonization event. Lineages endemic to putative source regions, including Australia and New Guinea, constitute derived groups. Divergence time estimates and probabilistic ancestral area reconstructions support a Neotropical origin of the group, and a Late Cretaceous (ca 82 Ma) colonization of Australasia out of the Fiji Islands and/or Borneo, which are consistent with a transoceanic dispersal event. Our results suggest that the endemic diversity within traditionally defined zoogeographic boundaries might have more complex evolutionary origins than previously envisioned.