Blowup for Biharmonic NLS

We consider the Cauchy problem for the biharmonic (i.\,e.~fourth-order) NLS with focusing nonlinearity given by $i \partial_t u = \Delta^2 u - \mu \Delta u -|u|^{2 \sigma} u$ for $(t,x) \in [0,T) \times \mathbb{R}^d$, where $0 < \sigma <\infty$ for $d \leq 4$ and $0 < \sigma \leq 4/(d-4)$ for $d \geq 5$; and $\mu \in \mathbb{R}$ is some parameter to include a possible lower-order dispersion. In the mass-supercritical case $\sigma > 4/d$, we prove a general result on finite-time blowup for radial data in $H^2(\mathbb{R}^d)$ in any dimension $d \geq 2$. Moreover, we derive a universal upper bound for the blowup rate for suitable $4/d < \sigma < 4/(d-4)$. In the mass-critical case $\sigma=4/d$, we prove a general blowup result in finite or infinite time for radial data in $H^2(\mathbb{R}^d)$. As a key ingredient, we utilize the time evolution of a nonnegative quantity, which we call the (localized) Riesz bivariance for biharmonic NLS. This construction provides us with a suitable substitute for the variance used for classical NLS problems. In addition, we prove a radial symmetry result for ground states for the biharmonic NLS, which may be of some value for the related elliptic problem.Comment: Revised version. Corrected some minor typos, added some remarks and included reference [12

on Rana Fuscigula and R. Angolensis.

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Zoology of Egypt; The Fishes of the Nile

Book containing plates of fishes of the Nile.https://knowledge.e.southern.edu/kweeks_coll/1037/thumbnail.jp

XXVI.— A List of Reptiles and Batrachians from the Congo Free State, with descriptions of two new snakes

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Cross-Lingual NER for Financial Transaction Data in Low-Resource Languages

We propose an efficient modeling framework for cross-lingual named entity recognition in semi-structured text data. Our approach relies on both knowledge distillation and consistency training. The modeling framework leverages knowledge from a large language model (XLMRoBERTa) pre-trained on the source language, with a student-teacher relationship (knowledge distillation). The student model incorporates unsupervised consistency training (with KL divergence loss) on the low-resource target language. We employ two independent datasets of SMSs in English and Arabic, each carrying semi-structured banking transaction information, and focus on exhibiting the transfer of knowledge from English to Arabic. With access to only 30 labeled samples, our model can generalize the recognition of merchants, amounts, and other fields from English to Arabic. We show that our modeling approach, while efficient, performs best overall when compared to state-of-the-art approaches like DistilBERT pre-trained on the target language or a supervised model directly trained on labeled data in the target language. Our experiments show that it is enough to learn to recognize entities in English to reach reasonable performance in a low-resource language in the presence of a few labeled samples of semi-structured data. The proposed framework has implications for developing multi-lingual applications, especially in geographies where digital endeavors rely on both English and one or more low-resource language(s), sometimes mixed with English or employed singly.Comment: 5 pages, 3 figures. Presented at the SIGIR 2023 Workshop on Knowledge Discovery from Unstructured Data in Financial Services (KDF

L'amorçage sémantique masqué en situation de cocktail party.

International audienceCette étude vise à tester l'automaticité du traitement sémantique durant la perception de la parole grâce à la situation de cocktail party. Les participants devaient effectuer une tâche de décision lexicale sur un item cible inséré dans un cocktail de parole. Celui-ci était composé de voix prononçant des mots sémantiquement liés à la cible (voix amorces) , et d'autres voix prononçant des mots sémantiquement indépendants les uns des autres (voix masquante). L'analyse des résultats a montré qu'un effet d'amorçage n'apparaissait que lorsque le nombre de voix amorces était strictement supérieur au nombre de voix masquantes, mettant en évidence un besoin d'intelligibilité de l'amorce et la nature stratégique de l'effet d'amorçage observé

Action in cognition: the case of language

Empirical research has shown that the processing of words and sentences is accompanied by activation of the brain's motor system in language users. The degree of precision observed in this activation seems to be contingent upon (1) the meaning of a linguistic construction and (2) the depth with which readers process that construction. In addition, neurological evidence shows a correspondence between a disruption in the neural correlates of overt action and the disruption of semantic processing of language about action. These converging lines of evidence can be taken to support the hypotheses that motor processes (1) are recruited to understand language that focuses on actions and (2) contribute a unique element to conceptual representation. This article explores the role of this motor recruitment in language comprehension. It concludes that extant findings are consistent with the theorized existence of multimodal, embodied representations of the referents of words and the meaning carried by language. Further, an integrative conceptualization of “fault tolerant comprehension” is proposed

Action perception theory of cognition and communication

A new perspective on cognition views cortical cell assemblies linking together knowledge about actions and perceptions not only as the vehicles of integrated action and perception processing but, furthermore, as a brain basis for a wide range of higher cortical functions, including attention, meaning and concepts, sequences, goals and intentions, and even communicative social interaction. This article explains mechanisms relevant to mechanistic action perception theory, points to concrete neuronal circuits in brains along with artificial neuronal network simulations, and summarizes recent brain imaging and other experimental data documenting the role of action perception circuits in cognition, language and communication

Acoustic cues for segmentation resist within speaker variation: An EEG study

In order to recognize spoken words, listeners must map sensory information from the acoustic input onto stored lexical entries. Because the speech signal is continuous, listeners must segment the speech stream in order to recognize words. To accomplish the task of segmentation listeners use their tacit knowledge of a wide range of patterns in their native language including cues from allophonic variation, phonotactic constraints, transitional probabilities, lexical stress etc. Among those cues, there is now a growing body of evidence suggesting that fine-grained acoustic information is available for lexical access and used for segmenting the speech stream. Although it is generally agreed that acoustic cues are used on line to segment the speech signal and to bias lexical access, some important questions remained unanswered. First we ought to know whether these cues are robust enough to be used in the context of multiple productions of the same segmentation as speech is by nature variable and listeners are never exposed to invariant speech. The second important open question is that of the timing of the use of the cues

The impact of fire on habitat use by the short-snouted elephant shrew ('Elephantulus brachyrhynchus') in North West Province, South Africa

Several studies have investigated the response of small mammal populations to fire, but few have investigated behavioural responses to habitat modification. In this study we investigated the impact of fire on home range, habitat use and activity patterns of the short-snouted elephant shrew (Elephantulus brachyrhynchus) by radio-tracking individuals before and after a fire event. All animals survived the passage of fire in termite mound refugia. Before the fire, grassland was used more than thickets, but habitat utilization shifted to thickets after fire had removed the grass cover. Thickets were an important refuge both pre- and post-fire, but the proportion of thicket within the home range was greater post-fire. We conclude that fire-induced habitat modification resulted in a restriction of E. brachyrhynchus movements to patches of unburned vegetation. This may be a behavioural response to an increase in predation pressure associated with a reduction in cover, rather than a lack of food. This study highlights the importance of considering the landscape mosaic in fire management and allowing sufficient island patches to remain post-fire ensures the persistence of the small mammal fauna