We generalize Baker–Bowler’s theory of matroids over tracts to orthogonal matroids, define orthogonal matroids with coefficients in tracts in terms of Wick functions, orthogonal signatures, circuit sets and orthogonal vector sets, and establish basic properties on functoriality, duality and minors. Our cryptomorphic definitions of orthogonal matroids over tracts provide proofs of several representation theorems for orthogonal matroids. In particular, we give a new proof that an orthogonal matroid is regular if and only if it is representable over ${\mathbb F}_2$ and ${\mathbb F}_3$, which was originally shown by Geelen [16], and we prove that an orthogonal matroid is representable over the sixth-root-of-unity partial field if and only if it is representable over ${\mathbb F}_3$ and ${\mathbb F}_4$.

Microwaves (MWs) have emerged as a promising sensing technology to complement optical methods for monitoring floating plastic litter. This study uses machine learning (ML) to identify optimal MW frequencies for detecting floating macroplastics (>5 cm) across S, C, and X-bands. Data were obtained from dedicated wideband backscattering radio measurements conducted in a controlled indoor scenario that mimics deep-sea conditions. The paper presents new strategies to directly analyze the frequency domain signals using ML algorithms, instead of generating an image from those signals and analyzing the image. We propose two ML workflows, one unsupervised, to characterize the difference in feature importance across the measured MW spectrum, and the other supervised, based on multilayer perceptron, to study the detection accuracy in unseen data. For the tested conditions, the backscatter response of the plastic litter is optimal at X-band frequencies, achieving accuracies up to 90% and 80% for lower and higher water wave heights, respectively. Multiclass classification is also investigated to distinguish between different types of plastic targets. ML results are interpreted in terms of the physical phenomena obtained through numerical analysis, and quantified through an energy-based metric.

Hurricane Irma devastated the island of Barbuda in September 2017. Motivated by the need to assess the population status of the endemic Barbuda Warbler Setophaga subita and resident Yellow Warbler S. petechia bartholemica, we used distance sampling to estimate total abundance (i.e. density and population size in a well-defined survey region, accounting for incomplete counts due to imperfect detection) in October 2017 and March 2019. Vocalising warblers were more detectable than non-vocalising warblers (two-tailed z scores >2.01, P values <0.04). In October 2017, detectability and density of the Barbuda Warbler were higher at points where the Yellow Warbler was undetected than detected (z > 2.20, P <0.03), suggesting competitive interactions following the hurricane. However, detectability did not differ (z = 0.45, P = 0.62) and density was higher (z = 2.11, P = 0.03) for the Barbuda Warbler at points where the Yellow Warbler was detected than undetected in March 2019, suggesting non-competitive coexistence after population recovery. The density (i.e. no. individuals/ha) and population size (no. individuals in the 9,000-ha survey region) of the Barbuda Warbler increased (z = -2.60, P = 0.01) from 0.27 (SE = 0.03) and 2,436 (SE = 261) in October 2017 to 0.40 (SE = 0.02) and 3,570 (SE = 171) in March 2019. The density and population size of the Yellow Warbler also increased (z = -2.40, P = 0.02) from 0.68 (SE = 0.03) and 6,093 (SE = 269) in October 2017 to 0.80 (SE = 0.04) and 7,158 (SE = 358) in March 2019. Owing to the small distribution range and threats from hurricanes and habitat loss on the island, the Barbuda Warbler should remain classified as “Vulnerable” to extinction. However, the more abundant and widely distributed Yellow Warbler should remain classified as of “Least Concern”.

We investigate the pullback measure attractors for non-autonomous stochastic p-Laplacian equations driven by nonlinear noise on thin domains. The concept of complete orbits for such systems is presented to establish the structures of pullback measure attractors. We first present some essential uniform estimates, as well as the existence and uniqueness of pullback measure attractors. A novel technical proof method is shown to overcome the difficulty of the estimates of the solutions in $W^{1,p}$ on thin domains. Then, we prove the upper semicontinuity of these measure attractors as the $(n + 1)$-dimensional thin domains collapse onto the lower n-dimensional space.

The article presents a revised dating of a major late medieval inquisition of heresy, challenging the dating of the records established since the 1880s. The inquisitor Petrus Zwicker’s proceedings against Brandenburgian and Pomeranian Waldensians in Stettin did not take place between November 1392 and March 1394, with an 11-month pause between March 1393 and February 1394, as has been the scholarly consensus up till now. Instead, the prosecution was a continuous process that started in November 1393 and lasted till late March 1394. The article discusses the problems of the established dating that is based on now-outdated information about the inquisitor’s itinerary and an ambiguous 15th-century commentary on the register volume. The internal evidence of the register, such as the way different deponents refer to the same events, strongly points towards an uninterrupted process. The revised timeline for the inquisitions solves several contradictions in interpreting the records and proposes new lines of inquiry. A novel reconstruction of the last Waldensian minister’s visit to Stettin and surroundings is provided in the last section of the article. In general, the article addresses the constant need to re-evaluate established interpretations of premodern sources, including those uncontested in the scholarship.

This work attempts to better understand the significance of morphological diversity among fungal-algal contact zones present in lichens. We used TEM to examine a variety of lichen symbioses involving non-trebouxialean green algae that show intraparietal penetration by the mycobiont. A principal focus was on Endocarpon pusillum, a well-known member of a family (Verrucariaceae; Eurotiomycetes) previously reported to be characterized by unwalled haustoria exposing a naked fungal protoplast. Peg-like haustoria arose from an inner layer(s) of the mycobiont cell wall that broke through outer layers and penetrated a short distance into the wall of the green algal symbiont (Diplosphaera). In both fungal and algal cells at the contact interface, lomasome-like vesicles and tubules occurred as modifications of the plasmalemma intermixed with wall materials at the inner surface of the cell wall. A fungal cell wall was consistently present around the haustorium, which resembled those depicted in earlier TEM studies of Verrucariaceae. Previously published micrographs of Verrucariaceae purporting to show wall-less haustoria surrounded by an empty space are believed to have been misinterpreted. However, in the isidiose Porina and foliicolous Calopadia, Byssoloma and Fellhanera species (Lecanoromycetes), we did observe extreme degrees of reduction in the mycobiont cell wall at symbiont contact interfaces. In those lichens, a broad area of the fungal cell bulged into the adjacent algal symbiont, broadly invaginating the wall of the latter and penetrating it intraparietally without differentiation of a distinct haustorial structure. The mycobiont wall surrounding such protrusions often thinned to near indistinguishability towards its extremity. The protrusion made direct contact with the algal cell wall; no empty space occurred between them. We propose that the short, peg-like intraparietal haustoria bind the symbionts and help maintain cell contacts amid the stresses of tissue expansion and shrinkage, thereby avoiding disruption of the continuous hydrophobic coating that facilitates transfer between them. Broader contact interfaces with extremely thin adjacent walls may facilitate solute flow between symbionts. Reciprocal penetration of algal protrusions into mycobiont cells, noted in Porina as well as other lichens studied previously, is a neglected but potentially significant indication that both symbionts may actively work to maintain functional contact interfaces.

A new species of the genus Verdeia is described from the continental slope of the Potiguar Basin, Rio Grande do Norte, Brazil at a depth of 150 m. Verdeia setosa sp. nov. is readily distinguished from its congeners by the ornamentation of the larger gnathopod 2 in males and the densely setose basis of pereopods 6–7. This is also a new record of the genus from Brazilian waters. We presented an amended diagnosis of the genus to accommodate all Verdeia species and discuss these changes. Furthermore, an identification key to the family Melitidae from Brazil is provided.

Adolescents may not necessarily have a specific mental health challenge to seek information on mental health. They may be genuinely curious on how to better understand these issues, especially when mental health is being discussed in school, among peers and with parents. The purpose of this study was to examine the frequency and factors associated with online information seeking about mental health among adolescents. A total of 702 high school students from Belgrade, Serbia, participated in the study and filled in an anonymous questionnaire about sociodemographics, digital behaviors and the Electronic Health Literacy Scale (eHEALS). The prevalence of seeking information about mental health in our study sample was 23.5% (165/702). The multivariate model showed that having a lower school performance, lower eHEALS score and browsing health blogs, social media and websites run by physicians and health institutions were independently associated with online information seeking about mental health. Additionally, searching for online information about psychoactive substances, bullying and medications was independently associated with online information seeking about mental health among adolescents. Adolescents are familiar with a variety of sources of online health information, but choose specific online platforms to read about mental health. These platforms could be utilized to promote mental well-being in high schools.

This paper develops methods for simplifying systems of partial differential equations (PDEs) that have families of conservation laws which depend on arbitrary functions of the independent or dependent variables. Cases are identified in which such methods can be combined with reduction using families of symmetries to give a multiple reduction; this is analogous to the double reduction of order for ordinary differential equations (ODE) with variational symmetries. Applications are given, including a widely used class of pseudoparabolic equations and several mean curvature equations.

Anapachydiscus (Anapachydiscus) haegerti n. sp., an ammonite belonging to the Pachydiscidae, is reported for the first time from the upper Campanian Northumberland Formation of Hornby Island, British Columbia. Thirty-five specimens have allowed for the complete ontogenetic reconstruction of the taxon as well as thanatocoenosic (death assemblage) observations with paleoecological implications for ammonoid early life. Although isolated juvenile specimens occur, instances of concretions containing a multitude of individuals are typical. One concretion yielding twenty-six early-stage juveniles lends support to a mode of preservation reflective of life association through a taphonomic process of capture and burial. The new species presents age-diagnostic utility as a distinct fossil within the molluscan assemblage of the Nostoceras (Didymoceras?) adrotans regional subzone; a highly constrained interval of the upper Campanian in the eastern North Pacific. A specimen attributed to Anapachydiscus (Anapachydiscus) cf. A. (A.) fascicostatus from the upper Campanian of the Cedar District Formation on Denman Island is also described, and the genus Anapachydiscus is retained with an emended diagnosis. Additional collections have enabled revised conceptualizations of Pachydiscus (Pachydiscus) hornbyense and Pachydiscus (Pachydiscus) ootacodensis accounting for the spectrum of variance within these species. Recognition of an upper Campanian P. (P.) ootacodensis–Pachydiscus (Pachydiscus) suciaensis Concurrent-range Zone is proposed for the eastern North Pacific to assist broader efforts of interregional biostratigraphic correlation given the endemic limitation of the latter taxon.

UUID: http://zoobank.org/d8eb27f6-7221-4efb-9548-ec2001986b19

Squamate faunas from the lower Eocene of Europe are rare. We here describe pleurodontan iguanian (potentially Geiseltaliellus Kuhn, 1944), scincoid, and Squamata indet. jaw remains from Cos locality (near the Caylus village, southwestern France). The age of the Cos deposit has been proposed to fit the MP 10−11 interval (MP 10b; late Ypresian). Thus, it either corresponds to the end of the Early Eocene Climatic Optimum (EECO) or slightly postdates it. Although very fragmentary, the finds represent the first evidence of these clades in this locality, which is one of the oldest from Phosphorites du Quercy, adding to the squamate paleobiodiversity of the site. Besides iguanians and scincoids, the fauna also includes gekkotans, glyptosaurids, varanoids, and a constrictor snake. Some of the genera from Cos are known solely from this locality, revealing a crucial part of the squamate history in Europe. In the last few years, our knowledge of the Paleocene and especially early Eocene lizard faunas has increased. This allows a better understanding of the faunas and their changes due to temperature changes and migrations. Records are still very sketchy at European localities, but the overall picture is somewhat clearer, even on a smaller scale. A small but visible drop in lizard diversity appears to be present at localities from MP 8−9 relative to those from MP 7, whereas at MP 10, the diversity slightly increased. This appears to correlate well with observed changes in temperature.

A new species of syngnathiform fish, Gerpegezhus daniaoriundus n. sp., from the Eocene Fur Formation of Denmark is described herein. The description is based on 17 specimens preserved in either soft diatomite or carbonate concretions. The two lithologies result in different preservation of the morphological features. Gerpegezhus daniaoriundus n. sp. exhibits a set of diagnostic features of the extinct monotypic family Gerpegezhidae and of the genus Gerpegezhus, including (1) greatly elongated body, (2) presence of ossified myoseptal tendons, (3) lower procurrent caudal-fin rays absent, (4) dorsal- and anal-fin spines absent, and (5) pelvic fin and girdle absent. It can be separated from the species Gerpegezhus paviai by having a much slenderer body bearing unpaired leaf-like appendages protruding from its ventral side, and completely different meristic values, including up to 39 (or 40) vertebrae, a total of 16 unbranched caudal-fin rays, dorsal and anal fins with 5 and 16 unbranched rays, respectively, and a different organization of body armor comprising two dorsal bilateral series of dermal plates. The occurrence of the genus Gerpegezhus from the Fur Formation provides a remarkable example of the biogeographic relationships between the North Sea realm and the Tethys in the earliest Eocene.

http://zoobank.org/3a57ae6b-faae-44c6-9a0a-aaeea03b57b3