Maximum-likelihood estimation of specific differential phase and attenuation in rain

Precise estimation of propagation parameters in precipitation media is of interest to improve the performance of communications systems and in remote sensing applications. In this paper, we present maximum-likelihood estimators of specific attenuation and specific differential phase in rain. The model used for obtaining the cited estimators assumes coherent propagation, reflection symmetry of the medium, and Gaussian statistics of the scattering matrix measurements. No assumptions about the microphysical properties of the medium are needed. The performance of the estimators is evaluated through simulated data. Results show negligible estimators bias and variances close to Cramer–Rao bounds

ATRA mechanically reprograms pancreatic stellate cells to suppress matrix remodelling and inhibit cancer cell invasion

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignancy with a dismal survival rate. Persistent activation of pancreatic stellate cells (PSCs) can perturb the biomechanical homoeostasis of the tumour microenvironment to favour cancer cell invasion. Here we report that ATRA, an active metabolite of vitamin A, restores mechanical quiescence in PSCs via a mechanism involving a retinoic acid receptor beta (RAR-β)-dependent downregulation of actomyosin (MLC-2) contractility. We show that ATRA reduces the ability of PSCs to generate high traction forces and adapt to extracellular mechanical cues (mechanosensing), as well as suppresses force-mediated extracellular matrix remodelling to inhibit local cancer cell invasion in 3D organotypic models. Our findings implicate a RAR-β/MLC-2 pathway in peritumoural stromal remodelling and mechanosensory-driven activation of PSCs, and further suggest that mechanical reprogramming of PSCs with retinoic acid derivatives might be a viable alternative to stromal ablation strategies for the treatment of PDAC

(Poly)phenolic content and profile and antioxidant capacity of whole-grain cookies are better estimated by simulated digestion than chemical extraction

It is widely recognized that the biological effects of phytochemicals cannot be attributed to the native compounds present in foods but rather to their metabolites endogenously released after intake. Bioavailability depends on bioaccessibility, which is the amount of the food constituent that is released from the matrix in the gastrointestinal tract. The use of chemical extraction to evaluate the content and profile of phytochemicals does not mirror the physiological situation in vivo, and their bioaccessibility should be considered while assessing their nutritional significance in human health. The current study was designed to compare the (poly)phenolic profile and content and antioxidant capacity of whole-grain (WG) cookies using chemical extraction and a more physiological approach based on simulated digestion. Three types of organic WG cookies (made with durum, Italian khorasan, or KAMUT\uae khorasan wheat) were considered, either fermented by Saccharomyces Cerevisiae or sourdough. Although the flour type and the fermentation process influenced the release of phytochemicals from the cookie matrix, in almost all samples, the simulated digestion appeared the most efficient procedure. Our results indicate that the use of chemical extraction for evaluation of the phytochemicals content and antioxidant capacity of food could lead to underestimation and underline the need for more physiological extraction methods

Phylogenetic analysis of the Pantomorus-Naupactus complex (Coleoptera: Curculionidae: Entiminae) from North and Central America

We undertook the first cladistic analysis of the Pantomorus-Naupactus complex (Coleoptera: Curculionidae) from North and Central America, based on 35 species and 61 morphological characters, plus 1151 bp of the mtDNA COI and Cyt b genes. The morphological and the combined matrices analyzed with TNT yielded a single most parsimonious cladogram that allows recognition of two main lineages within the Pantomorus-Naupactus complex in North and Central America. One is represented by the species formerly placed in Phacepholis and the Pantomorus species group II sensu Sharp, ranging along the Pacific coast of Central America and Mexico and reaching the Great Plains of North America in the United States, yet not occurring in South America. The other lineage is represented by the species of Naupactus and Pantomorus: species group I, with closer relationships to the South American species of these genera. The Pantomorus group I includes the type species of the genus P. albosignatus Boheman whereas the Pantomorus group II includes the type species of Athetetes Pascoe, 1886 (A. globicollis Pascoe). Based on the results of our phylogenetic analysis, we recommend retaining the name Pantomorus Schoenherr for most species of the Pantomorus group I, except P. stupidus (Boheman) and P. femoratus Sharp which should be transferred to Naupactus Dejean. Moreover, we enlarge the previous concept of Phacepholis to include most species of the Pantomorus group II, and we establish the synonymy of Athetetes Pascoe, 1886 with Phacepholis Horn, 1876, being the latter the valid name, by priority.We undertook the first cladistic analysis of the Pantomorus-Naupactus complex (Coleoptera: Curculionidae) from North and Central America, based on 35 species and 61 morphological characters, plus 1151 bp of the mtDNA COI and Cyt b genes. The morphological and the combined matrices analyzed with TNT yielded a single most parsimonious cladogram that allows recognition of two main lineages within the Pantomorus-Naupactus complex in North and Central America. One is represented by the species formerly placed in Phacepholis and the Pantomorus species group II sensu Sharp, ranging along the Pacific coast of Central America and Mexico and reaching the Great Plains of North America in the United States, yet not occurring in South America. The other lineage is represented by the species of Naupactus and Pantomorus: species group I, with closer relationships to the South American species of these genera. The Pantomorus group I includes the type species of the genus P. albosignatus Boheman whereas the Pantomorus group II includes the type species of Athetetes Pascoe, 1886 (A. globicollis Pascoe). Based on the results of our phylogenetic analysis, we recommend retaining the name Pantomorus Schoenherr for most species of the Pantomorus group I, except P. stupidus (Boheman) and P. femoratus Sharp which should be transferred to Naupactus Dejean. Moreover, we enlarge the previous concept of Phacepholis to include most species of the Pantomorus group II, and we establish the synonymy of Athetetes Pascoe, 1886 with Phacepholis Horn, 1876, being the latter the valid name, by priority.Fil: Rosas, María V.. Universidad Nacional Autónoma de México; MéxicoFil: Morrone, Juan José. Universidad Nacional Autónoma de México; MéxicoFil: del Rio, Maria Guadalupe. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Lanteri, Analia Alicia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; Argentin

Composable security in relativistic quantum cryptography

Relativistic protocols have been proposed to overcome certain impossibility results in classical and quantum cryptography. In such a setting, one takes the location of honest players into account, and uses the signalling limit given by the speed of light to constraint the abilities of dishonest agents. However, composing such protocols with each other to construct new cryptographic resources is known to be insecure in some cases. To make general statements about such constructions, a composable framework for modelling cryptographic security in Minkowski space is required. Here, we introduce a framework for performing such a modular security analysis of classical and quantum cryptographic schemes in Minkowski space. As an application, we show that (1) fair and unbiased coin flipping can be constructed from a simple resource called channel with delay; (2) biased coin flipping, bit commitment and channel with delay through any classical, quantum or post-quantum relativistic protocols are all impossible without further setup assumptions; (3) it is impossible to securely increase the delay of a channel, given several short-delay channels as ingredients. Results(1) and (3) imply in particular the non-composability of existing relativistic bit commitment and coin flipping protocols

Multi-agent paradoxes beyond quantum theory

Which theories lead to a contradiction between simple reasoning principles and modelling observers' memories as physical systems? Frauchiger and Renner have shown that this is the case for quantum theory, with a thought experiment that leads to a multi-agent paradox. Here we generalize the conditions of the Frauchiger-Renner result so that they can be applied to arbitrary physical theories, and in particular to those expressed as generalized probabilistic theories (GPTs). We then apply them to a particular GPT, box world, and find a deterministic contradiction in the case where agents may share a PR box, which is stronger than the quantum paradox, in that it does not rely on post-selection. Obtaining an inconsistency for the framework of GPTs broadens the landscape of theories which are affected by the application of classical rules of reasoning to physical agents. In addition, we model how observers' memories may evolve in box world, in a way consistent with Barrett's criteria for allowed operations

New records of recently described chemosymbiotic bivalves for mud volcanoes within the European waters (Gulf of Cádiz)

Chemosymbiotic bivalves are important members of cold seep communities and information on their distribution in theEuropean waters is still quite scarce. This study reports the presence of living populations and shell remains of some recently described bivalves such as Lucinoma asapheus, Solemya elarraichensis and Acharax gadirae as well as Bathymodiolus sp. in the mud volcanoes of the Spanish Atlantic waters. Living populations of these species were thus far only found in Anastasya, Aveiro and Almazán mud volcanoes, together with other chemosymbiotic metazoa (Siboglinum spp.), suggesting the presence of moderate seepage activity. In other mud volcanoes (Albolote, Gazul), the benthic communities are dominated by sessile filter feeders on authigenic carbonates (chimneys, slabs) and only the shell remains of some chemosymbiotic bivalves were found, indicating earlier or very low seepage conditions. The present study elaborates on the known distribution of L. asapheus and S. elarraichensis to the European waters of the Gulf of Cádiz

An EM/MCMC Markov-witching GARCH behavioral algorithm for random-length lumber futures trading

This paper tests using two-regime Markov-switching models with asymmetric, time-varying exponential generalized autoregressive conditional heteroskedasticity (MS-EGARCH) variances in random-length lumber futures trading. By assuming a two-regime context (a low s=1 and high s=2 volatility), a trading algorithm was simulated with the following trading rule: invest in lumber futures if the probability of being in the high-volatility regime s=2 is lower or equal to 50%, or invest in the 3-month U.S. Treasury bills (TBills) otherwise. The rationale tested in this paper was that using a two-regime Markov-switching (MS) algorithm leads to an overperformance against a buy-and-hold strategy in lumber futures. To extend the current literature in MS trading algorithms, two location parameter scenarios were simulated. The first uses an unconditional mean or expected value (no factors), and the second incorporates market and behavioral factors. With weekly simulations form 2 January 1994 to 28 July 2023, the results suggest that using MS-EGARCH models in a no-factors scenario is appropriate for active lumber futures trading with an accumulated return of 158.33%. Also, the results suggest that it is not useful to add market and behavioral factors in the MS-GARCH estimation because it leads to a lower performance.Junta de Extremadura | Ref. GR2116