Previous Classification Schemes Research Articles

Africa's Crustal Architecture Inferred From Probabilistic and Perturbational Inversion of Ambient Noise: ADAMA

AbstractAfrica's continental crust hosts a variety of geologic terrains and is crucial for understanding the evolution of its longest‐lived cratons. However, few of its seismological models are yet to incorporate the largest continent‐wide noise dispersion data sets. Here, we report on new insights into Africa's crustal architecture obtained using a new data set and model assessment product, ADAMA, which comprises a large ensemble of short‐period surface wave dispersion measurements: 5–40 s. We construct a continent‐wide model of Africa's Crust Evaluated with ADAMA's Rayleigh Phase maps (ACE‐ADAMA‐RP). Dispersion maps, and uncertainties, are obtained with a probabilistic approach. This model update, and a crustal taxonomy derived from unsupervised machine learning, reveals that the architecture of Africa's crust can be classified into two main types: primitive (C1: faster velocities with little gradients) and modified (C2–C4: slower velocities in the shallow crust with more pronounced gradients). The Archean shields are “primitive,” showing little variation or secular evolution. The basins, orogens, and continental margins are “modified” and retain imprints of surface deformation. The crustal taxonomy is obtained without a‐priori geological information and differs from previous classification schemes. While most of our reported features are robust, probabilistic modeling suggests caution in the quantitative interpretations where illumination is compromised by low‐quality measurements, sparse coverage or both. Future extension of our approach to other complementary seismological and geophysical data sets—for example, multimode earthquake dispersion, receiver functions, gravity, and mineral physics, will enable continent‐wide lithospheric modeling that extends resolution to the upper mantle.

Ordered ground state configurations of the asymmetric Wigner bilayer system-Revisited with unsupervised learning.

We have reanalyzed the rich plethora of ground state configurations of the asymmetric Wigner bilayer system that we had recently published in a related diagram of states [Antlanger et al., Phys. Rev. Lett. 117, 118002 (2016)], comprising roughly 60 000 state points in the phase space spanned by the distance between the plates and the charge asymmetry parameter of the system. In contrast to this preceding contribution where the classification of the emerging structures was carried out "by hand," we have used for the present contribution machine learning concepts, notably based on a principal component analysis and a k-means clustering approach: using a 30-dimensional feature vector for each emerging structure (containing relevant information, such as the composition of the configuration as well as the most relevant order parameters), we were able to reanalyze these ground state configurations in a considerably more systematic and comprehensive manner than we could possibly do in the previously published classification scheme. Indeed, we were now able to identify new structures in previously unclassified regions of the parameter space and could considerably refine the previous classification scheme, thereby identifying a rich wealth of new emerging ground state configurations. Thorough consistency checks confirm the validity of the newly defined diagram of states.

Beyond BPT: A New Multidimensional Diagnostic Diagram for Classifying Power Sources Tested Using the SAMI Galaxy Survey

Current methods of identifying the ionizing source of nebular emission in galaxies are well defined for the era of single-fiber spectroscopy, but still struggle to differentiate the complex and overlapping ionization sources in some galaxies. With the advent of integral field spectroscopy, the limits of these previous classification schemes are more apparent. We propose a new method for distinguishing the ionizing source in resolved galaxy spectra by use of a multidimensional diagnostic diagram that compares emission-line ratios with velocity dispersion on a spaxel-by-spaxel basis within a galaxy. This new method is tested using the Sydney-Australian-Astronomical-Observatory Multi-object Integral-Field Spectrograph Galaxy Survey (SAMI) Data Release 3 (DR3), which contains 3068 galaxies at z < 0.12. Our results are released as ionization maps available alongside the SAMI DR3 public data. Our method accounts for a more diverse range of ionization sources than the standard suite of emission-line diagnostics; we find 1433 galaxies with a significant contribution from non-star-forming ionization using our improved method as compared to 316 galaxies identified using only emission-line ratio diagnostics. Within these galaxies, we further identify 886 galaxies hosting unique signatures inconsistent with standard ionization by H ii regions, active galactic nuclei, or shocks. These galaxies span a wide range of masses and morphological types and comprise a sizable portion of the galaxies used in our sample. With our revised method, we show that emission-line diagnostics alone do not adequately differentiate the multiple ways to ionize gas within a galaxy.

A molecular phylogeny of Noctuini (Lepidoptera: Noctuidae: Noctuinae)

Abstract The tribe Noctuini is comprised over 520 species; many are economically important species that impact human agriculture. Despite their diversity and relevance, relationships of Noctuini have been difficult to resolve. There have been extensive morphological revisions of some of these taxa (e.g., Agrotis Ochsenheimer, Euxoa Hübner); however, there are no studies that focus exclusively on the phylogenetic relationships of the Noctuini. Currently, Noctuini are separated into 2 subtribes, Agrotina and Noctuina. In this study, we tested previous classification schemes with 2 analyses. The total evidence analysis utilized 3 loci for 3 outgroup taxa and 54 noctuine species. Using museum specimens, we collected data from cytochrome oxidase I (COI), Dopa Decarboxylase (DDC), and Elongation factor 1-α (EF1-α) to generate a dataset of 1,378 base pairs (bp) for a total evidence approach. We also used previously published COI sequences for 626 species, resulting in a matrix of 690 bp, termed “the barcode analysis.” We used both Maximum Likelihood and Bayesian approaches for the total evidence analysis, and ML for the barcode analysis. In both sets of results, we found equivocal support for monophyletic Agrotina and Noctuina. We found strong support for smaller, well-described genera (e.g., Spaelotis), but poor support for large genera such as Euxoa, Feltia Walker, and Agrotis. It is likely that a combination of limited taxon/gene sampling, limited gene choice, and the rapid evolution of these species resulted in a lack of phylogenetic resolution in the total evidence topologies. Based on these results, we recommend increased taxon sampling and inclusion of loci that target these rapidly evolving lineages to achieve a better understanding of the phylogeny of Noctuini and its genera.

A new comprehensive Classification Scheme for ECU Tendon Problems at the Wrist.

Based on a systematic review of the literature, description of previous classification schemes and new anatomical knowledge, a new comprehensive classification scheme for ECU tendon problems at the wrist is described.

Use of artificial neural network to evaluate cadmium contamination in farmland soils in a karst area with naturally high background values

In recent years, the naturally high background value region of Cd derived from the weathering of carbonate has received wide attention. Due to the significant difference in soil Cd content and bioavailability among different parent materials, the previous land classification scheme based on total soil Cd content as the classification standard, has certain shortcomings. This study aims to explore the factors influencing soil Cd bioavailability in typical karst areas of Guilin and to suggest a scientific and effective farmland use management plan based on the prediction model. A total of 9393 and 8883 topsoil samples were collected from karst and non-karst areas, respectively. Meanwhile, 149 and 145 rice samples were collected together with rhizosphere soil in karst and non-karst areas, respectively. The results showed that the higher CaO level in the karst area was a key factor leading to elevated soil pH value. Although Cd was highly enriched in karst soils, the higher pH value and adsorption of Mn oxidation inhibited Cd mobility in soils. Conversely, the Cd content in non-karst soils was lower, whereas the Cd level in rice grains was higher. To select the optimal prediction model based on the correlation between Cd bioaccumulation factors and geochemical parameters of soil, artificial neural network (ANN) and linear regression prediction models were established in this study. The ANN prediction model was more accurate than the traditional linear regression model according to the evaluation parameters of the test set. Furthermore, a new land classification scheme based on an ANN prediction model and soil Cd concentration is proposed in this study, making full use of the spatial resources of farmland to ensure safe rice consumption.

A proposed new mineralogical classification system for granitic pegmatites

ABSTRACTThe current classification of granitic pegmatites, originally introduced by Černý (1991a), has been the accepted system for grouping pegmatites of diverse mineralogy and chemistry for nearly three decades. Despite its general acceptance, several issues have been highlighted (Müller et al. 2022) which have imposed some limitations on its use and therefore necessitated the need to reevaluate its methodology. A new classification for granitic pegmatites is proposed in an attempt to be more inclusive of pegmatite types omitted in previous classification schemes. The new approach utilizes a more comprehensive suite of accessory minerals and defines three pegmatite groups which are genetically related to granite plutons and the anatexis of metaigneous and metasedimentary protoliths. Pegmatites belonging to Groups 1 and 2 are generated from the residual melts of S-, A-, and I-type granite magmatism (RGM) as well as being direct products of anatexis (DPA), whereas Group 3 pegmatites are only derived by anatexis.

Primary cutaneous lymphoma: the 2018 update of the WHO-EORTC classification

Primary cutaneous lymphomas are a heterogeneous group of cutaneous T-cell lymphomas (CTCL) and cutaneous B-cell lymphomas (CBCL) that present in the skin with no evidence of extracutaneous disease at the time of diagnosis. In the last decade the 2005 WHO-EORTC consensus classification has served as a golden standard for the diagnosis and classification of these conditions. Recently, an updated version of the WHO-EORTC was published. This classification contains several new entities, including primary cutaneous acral CD8+ T-cell lymphoma and EBV-positive mucocutaneous ulcer, while other conditions were slightly modified. Herein, the characteristic features of the different types of CTCL and CBCL are presented, differences with previous classification schemes discussed and the results of more recent molecular studies with clinical implications for these conditions reviewed. In addition, an update of the frequency and survival of the different types of primary cutaneous lymphomas is provided.

Research on aesthetic models based on neural architecture search

Computational aesthetics, which uses computers to learn human aesthetic habits and ultimately replace humans in scoring images, has become a hot topic in recent years due to its wide application. Most of the initial research is to manually extract features and use classifiers such as support vector machines to score images. With the development of deep learning, traditional manual feature extraction methods are gradually replaced by convolutional neural networks to extract more comprehensive features. However, it is a huge challenge to artificially design an aesthetic neural network. Recently, Neural Architecture Search has upsurged to find suitable neural networks for many tasks in deep learning. In this paper, we first attempt to combine Neural Architecture Search with computational aesthetics. We design and apply a customized progressive differentiable architecture search strategy to obtain a light-weighted and efficient aesthetic baseline model. In addition, we simulate the multi-person rating mechanism by outputting the distribution of the aesthetic value of the image, replacing the previous classification scheme of judging the beauty and unbeauty of the image by the threshold value, and propose a self-weighted Earth Mover’s Distance loss to better fit human subjective scoring. Based on the baseline model, we further introduce several strategies including an attention mechanism, the dilated convolution, and adaptive pooling, to enhance the performance. Finally, we design several groups of comparative experiments to demonstrate the effectiveness of our baseline aesthetic model and the introduced improvement strategies.

Symmetry Classes of Open Fermionic Quantum Matter

We present a full symmetry classification of fermion matter in and out of thermal equilibrium. Our approach starts from first principles, the ten different classes of linear and anti-linear state transformations in fermionic Fock spaces, and symmetries defined via invariance properties of the dynamical equation for the density matrix. The object of classification are then the generators of reversible dynamics, dissipation and fluctuations featuring in the generally irreversible and interacting dynamical equations. A sharp distinction between the symmetries of equilibrium and out of equilibrium dynamics, respectively, arises from the different role played by `time' in these two cases: In unitary quantum mechanics as well as in `micro-reversible' thermal equilibrium, anti-linear transformations combined with an inversion of time define time reversal symmetry. However, out of equilibrium an inversion of time becomes meaningless, while anti--linear transformations in Fock space remain physically significant, and hence must be considered in autonomy. The practical consequence of this dichotomy is a novel realization of antilinear symmetries (six out of the ten fundamental classes) in non-equilibrium quantum dynamics that is fundamentally different from the established rules of thermal equilibrium. At large times, the dynamical generators thus symmetry classified determine the steady state non-equilibrium distributions for arbitrary interacting systems. To illustrate this principle, we consider the fixation of a symmetry protected topological phase in a system of interacting lattice fermions. More generally, we consider the practically important class of mean field interacting systems, represented by Gaussian states. This class is naturally described in the language of non-Hermitian matrices, which allows us to compare to previous classification schemes in the literature.

Phylogenomics of Ichneumoninae (Hymenoptera, Ichneumonidae) reveals pervasive morphological convergence and the shortcomings of previous classifications

AbstractThe evolutionary history of Ichneumoninae, the largest subfamily of ichneumonid wasps, is investigated using genomic ultraconserved elements (UCEs). The dataset includes 147 species in 130 genera of Ichneumoninae and 155 outgroup taxa from 19 subfamilies. Matrices with varying degrees of completeness were analysed with different partition schemes and the resulting topologies were found to be mostly congruent. All analyses recovered Ichneumoninae as a monophyletic group, sister to all other Ichneumoniformes except Agriotypinae. Almost no support was found for previous tribal classification schemes, except that the tribes Phaeogenini and Platylabini are largely monophyletic. A new tribal classification is proposed based on the relationships recovered, consisting of seven tribes: Alomyini Förster, Phaeogenini Förster, Notosemini Townes, Eurylabini Heinrich, Platylabini Berthoumieu, Ichneumonini Latreille and a new monogeneric tribe, Abzariini Santos &amp; Wahl. As documented in other lineages of Ichneumonidae, pervasive morphological convergence poses a challenge to the establishment of higher‐level groups that are both monophyletic and diagnosable. Extremely short branches at the base of the Ichneumoninae clade suggest that the group may have undergone a rapid radiation when it first diverged, potentially associated with its specialization on lepidopteran hosts. Multiple changes in the morphology of the female abdomen suggest that morphological convergence is associated with multiple transitions in the use of pupal versus larval hosts across the subfamily. The results demonstrate the power of phylogenomic approaches to resolve evolutionary relationships in hyper‐diverse and poorly studied insect groups and to provide a framework for testing evolutionary hypotheses.

Microglial peri-somatic abutments classify two novel types of GABAergic neuron in the inferior colliculus.

Emerging evidence suggests functional roles for microglia in the healthy, mature nervous system. However, we know little of the cellular density and ramified morphology of microglia in sensory systems, and even less of their inter-relationship with inhibitory neurons. We therefore conducted fluorescent multi-channel immunohistochemistry and confocal microscopy in guinea pigs of both sexes for Iba1, GAD67, GFAP, calbindin, and calretinin. We explored these markers in the inferior colliculi (IC), which contain sub-regions specialized for different aspects of auditory processing. First, we found that while the density of Iba1+ somata is similar throughout the IC parenchyma, Iba1+ microglia in dorsal cortex are significantly more ramified than those in the central nucleus or lateral cortex. Conversely, Iba1+ ramifications in ventral central nucleus, a region with the highest density of GAD67+ (putative GABAergic) neurons in IC, are longer with fewer ramifications. Second, we observed extensive abutments of ramified Iba1+ processes onto GAD67+ somata throughout the whole IC and developed novel measures to quantify these. Cluster analyses revealed two novel sub-types of GAD67+ neuron that differ in the quantity of Iba1+ somatic abutments they receive. Unlike previous classification schemes for GAD67+ neurons in IC, these clusters are not related to GAD67+ soma size. Taken together, these data demonstrate that microglial ramifications vary between IC sub-regions in the healthy, adult IC, possibly related to the ongoing demands of their niche. Furthermore, Iba1+ abutments onto neuronal somata are a novel means by which GAD67+ neurons can be classified.

A New Subclass of Exoribonuclease-Resistant RNA Found in Multiple Genera of Flaviviridae.

Viruses have developed innovative strategies to exploit the cellular machinery and overcome the antiviral defenses of the host, often using specifically structured RNA elements. Examples are found in the Flavivirus genus (in the family Flaviviridae), where during flaviviral infection, pathogenic subgenomic flaviviral RNAs (sfRNAs) accumulate in the cell. These sfRNAs are formed when a host cell 5' to 3' exoribonuclease degrades the viral genomic RNA but is blocked by an exoribonuclease-resistant RNA structure (xrRNA) located in the viral genome's 3' untranslated region (UTR). Although known to exist in several Flaviviridae genera, the full distribution and diversity of xrRNAs in this family were unknown. Using the recently solved high-resolution structure of an xrRNA from the divergent flavivirus Tamana bat virus (TABV) as a reference, we used bioinformatic searches to identify xrRNAs in the remaining three genera of Flaviviridae: Pegivirus, Pestivirus, and Hepacivirus We biochemically and structurally characterized several examples, determining that they are genuine xrRNAs with a conserved fold. These new xrRNAs look superficially similar to the previously described xrRNAs but possess structural differences making them distinct from previous classes of xrRNAs. Overall, we have identified the presence of xrRNA in all four genera of Flaviviridae, but not in all species. Our findings thus require adjustments of previous xrRNA classification schemes and expand the previously known distribution of xrRNA in Flaviviridae.IMPORTANCE The members of the Flaviviridae comprise one of the largest families of positive-sense single-stranded RNA (+ssRNA) and are divided into the Flavivirus, Pestivirus, Pegivirus, and Hepacivirus genera. The genus Flavivirus contains many medically relevant viruses such as Zika virus, dengue virus, and Powassan virus. In these, a part of the RNA of the virus twists up into a distinct three-dimensional shape called an exoribonuclease-resistant RNA (xrRNA) that blocks the ability of the cell to "chew up" the viral RNA. Hence, part of the RNA of the virus remains intact, and this protected part is important for viral infection. These xrRNAs were known to occur in flaviviruses, but whether they existed in the other members of the family was not known. In this study, we identified a new subclass of xrRNA found not only in flaviviruses but also in the remaining three genera. The fact that these structured viral RNAs exist throughout the Flaviviridae family suggests they are important parts of the infection strategy of diverse pathogens, which could lead to new avenues of research.

Classifying rodent diets for comparative research

AbstractThe foods consumed by animals reflect their adaptations and ecological roles, which makes diet an important trait for ecological, evolutionary, and paleobiological research. Rodents are the most species‐rich order of mammals and are also ecologically diverse, consuming a wide range of foods.To relate form with function, and to study diversification in the context of diet and feeding, researchers should follow classification schemes that capture diet composition.We evaluated existing diet datasets for mammals as well as previous classification schemes developed for rodents. To propose a suitable categorical scheme, we defined splits within plant‐eating and animal‐eating rodents, aiming to capture the intrinsic differences in diet composition in terms of the accessibility, nutrient content, and digestibility of various food items.Our proposal includes eight categories (Carnivore, Folivore, Frugivore, Granivore, Omnivore, Specialist Herbivore, Unknown, and Vermivore) in which species can be assigned with information from species accounts and field guides. To avoid ambiguity, we provide examples and detailed criteria for each diet category.For biologically tractable comparative research, we ask researchers to use our diet categories for rodent species. The categories can also be applied at other taxonomic levels or to different populations, sexes, or ontogenetic stages. We call for further study of the natural history of small mammals and the uptake of primary data into open databases.

CLASSIFICATION OF ACL TEARS IN THE PEDIATRIC AND ADOLESCENT POPULATION

Background:There have been previous imaging classification schemes in the literature that described ACL tears in adults and pediatric patients. More recent publications have described the epidemiology, injury mechanisms, and repair versus reconstruction techniques. None have proposed an arthroscopic classification for pediatric patients.Purpose:To describe our experience with a novel arthroscopic classification using 4 patterns of ACL tears depending on the type of tear and the tissue quality.Methods:An IRB approved prospective with 2 parts to this study:Part 1: Single center prospective case series using descriptive statistics of intraoperative findings. We included children ≤18 years old with an ACL tear who underwent surgery within 8 weeks of injury. Those with associated ligamentous injuries or revision surgery were excluded. We proposed a 4-stage classification as follows: I. Avulsion off femur II. <10% tear from femoral end III. Midsubstance tear IV. Single bundle tear.Part 2: Four fellowship-trained surgeons from two tertiary children’s hospitals classified ACL injury based on intraoperative video of 33 randomly selected surgeries. 2 rounds of classification were performed. Inter and intra-observer reliability studies were calculated using Kappa statistics.Results:120 patients (73 males and 47 females) with mean age of 16 (9-20) years and mean BMI 26 (16-51) were included in this study. 59 patients (49%) had left sided injury while 61 (51%) had right sided injury. 29 (24%) patients reported contact injury while 91 (76%) reported non-contact. Isolated ACL injury was recorded in 49 patients only (41%) while concomitant injuries were recorded in 71 patients (59%). The most common associated injury was the lateral meniscus tear (33%), followed by lateral and medial meniscus tear (13.4%). According to our classification, 23 (19.2%) patients were type I, 15 (12.5%) were type II, 65 (54.2%) were type III, and 17 (14.2%) were type IV. The intra-rater reliability was excellent for 2 reviewers, good for 1 and marginal for another. The overall inter rater reliability for all 4 reviewers was marginal for both readings (k=0.35, 95% CI: 0.23-0.44; k=0.26, 95%CI: 0.16-0.35 respectively).Conclusion:With renewed interest in ACL repairs and techniques, a classification system for ACL tears can guide a proper surgical plan. Our classification system provides a step to achieve this goal. It showed overall good intra-observer reliability, with marginal inter-observer reliability.

Shape Dependence of Falling Snow Crystals’ Microphysical Properties Using an Updated Shape Classification

We present ground-based in situ snow measurements in Kiruna, Sweden, using the ground-based in situ instrument Dual Ice Crystal Imager (D-ICI). D-ICI records dual high-resolution images from above and from the side of falling natural snow crystals and other hydrometeors with particle sizes ranging from 50 μ m to 4 mm. The images are from multiple snowfall seasons during the winters of 2014/2015 to 2018/2019, which span from the beginning of November to the middle of May. From our images, the microphysical properties of individual particles, such as particle size, cross-sectional area, area ratio, aspect ratio, and shape, can be determined. We present an updated classification scheme, which comprises a total of 135 unique shapes, including 34 new snow crystal shapes. This is useful for other studies that are using previous shape classification schemes, in particular the widely used Magono–Lee classification. To facilitate the study of the shape dependence of the microphysical properties, we further sort these individual particle shapes into 15 different shape groups. Relationships between the microphysical properties are determined for each of these shape groups.

Neotropical Turtle Blood Flukes: Two New Genera and Species from the Amazon River Basin with a Key to Genera and Comments on a Marine-Derived Parasite Lineage in South America

Two new genera and species of freshwater turtle blood flukes (TBFs) are described herein based on specimens infecting the nephritic and mesenteric blood vessels of "matamatas" (a side-necked turtle, Chelus fimbriata [Schneider, 1783] [Pleurodira: Chelidae]) from the Amazon River Basin, Peru. These taxa comprise the first-named species and the first-proposed genera of freshwater TBFs from the continent of South America. A new comparison of all TBF genera produced 6 morphologically diagnosed groups that are discussed in light of previous TBF classification schemes and a novel phylogenetic hypothesis based on the nuclear large subunit ribosomal DNA (28S). Considering external and internal anatomical features, species of the new genera (Atamatam Bullard and Roberts n. gen., Paratamatam Bullard and Roberts n. gen.) are most similar to each other and are together most similar to those of several marine TBF genera. The 28S phylogenetic analysis supported the monophyly of all 6 morphologically diagnosed groups of genera. Most notably, the freshwater TBFs of South America comprise a derived group nested within the clade that includes the paraphyletic marine TBFs. Not surprisingly in light of morphology, another marine TBF lineage (Neospirorchis Price, 1934) clustered with the freshwater TBFs of Baracktrema Roberts, Platt, and Bullard, 2016 and Unicaecum Stunkard, 1925. Our results, including an ancestral state reconstruction, indicated that (1) freshwater TBFs have colonized marine turtles twice independently and that (2) the South American freshwater TBFs comprise a marine-derived lineage. This is the first evidence that TBFs have twice independently transitioned from a marine to freshwater definitive host. Marine incursion is considered as a possible mechanism affecting the natural history of marine-derived freshwater TBFs in South America. A dichotomous key to accepted TBF genera is provided.

Pearls and Updates in Dermatopathology for the General Surgical Pathologist: Experts Weigh In on What You Need to Know.

Pearls and Updates in Dermatopathology for the General Surgical Pathologist: Experts Weigh In on What You Need to Know.

Testing the higher-level phylogenetic classification of Digenea (Platyhelminthes, Trematoda) based on nuclear rDNA sequences before entering the age of the 'next-generation' Tree of Life.

Digenea Carus, 1863 represent a highly diverse group of parasitic platyhelminths that infect all major vertebrate groups as definitive hosts. Morphology is the cornerstone of digenean systematics, but molecular markers have been instrumental in searching for a stable classification system of the subclass and in establishing more accurate species limits. The first comprehensive molecular phylogenetic tree of Digenea published in 2003 used two nuclear rRNA genes (ssrDNA = 18S rDNA and lsrDNA = 28S rDNA) and was based on 163 taxa representing 77 nominal families, resulting in a widely accepted phylogenetic classification. The genetic library for the 28S rRNA gene has increased steadily over the last 15 years because this marker possesses a strong phylogenetic signal to resolve sister-group relationships among species and to infer phylogenetic relationships at higher levels of the taxonomic hierarchy. Here, we have updated the database of 18S and 28S rRNA genes until December 2017, we have added newly generated 28S rDNA sequences and we have reassessed phylogenetic relationships to test the current higher-level classification of digeneans (at the subordinal and subfamilial levels). The new dataset consisted of 1077 digenean taxa allocated to 106 nominal families for 28S and 419 taxa in 98 families for 18S. Overall, the results were consistent with previous higher-level classification schemes, and most superfamilies and suborders were recovered as monophyletic assemblages. With the advancement of next-generation sequencing (NGS) technologies, new phylogenetic hypotheses from complete mitochondrial genomes have been proposed, although their power to resolve deep levels of trees remains controversial. Since data from NGS methods are replacing other widely used markers for phylogenetic analyses, it is timely to reassess the phylogenetic relationships of digeneans with conventional nuclear rRNA genes, and to use the new analysis to test the performance of genomic information gathered from NGS, e.g. mitogenomes, to infer higher-level relationships of this group of parasitic platyhelminths.

Physiological Profile of Neuropeptide Y-Expressing Neurons in Bed Nucleus of Stria Terminalis in Mice: State of High Excitability.

Both, the anterior bed nucleus of the stria terminalis (BNST) and the neuropeptide Y (NPY) system are involved in shaping fear and defensive responses that adapt the organism to potentially life-threatening conditions. NPY is expressed in the BNST but NPY-expressing neurons in this critical hub in the stress response network have not been addressed before. Therefore, we performed whole-cell patch-clamp recordings in acute slices of anterior BNST from Npy-hrGFP transgenic mice to identify and characterize NPY-expressing neurons. We show that NPY-positive and NPY-negative neurons in anterior BNST match the previous classification scheme of type I (Regular Spiking), type II (Low-Threshold Bursting), and type III (fast Inward Rectifying) cells, although the proportion of these physiological phenotypes was similar within both neuronal subpopulations. However, NPY-positive and NPY-negative neurons possessed distinct intrinsic electrophysiological properties. NPY-positive neurons displayed higher input resistance and lower membrane capacitance, corresponding to small cell bodies and shorter less ramified dendrites, as compared to their NPY-negative counterparts. Furthermore, NPY-positive neurons generated higher frequent series of action potentials upon membrane depolarization and displayed significantly lower GABAA receptor-mediated synaptic responsiveness during evoked, spontaneous, and elementary synaptic activity. Taken together, these properties indicate an overall state of high excitability in NPY-positive neurons in anterior BNST. In view of the role of the anterior BNST in anxiety- and stress-related behaviors, these findings suggest a scenario where NPY-positive neurons are preferentially active and responsive to afferent inputs, thereby contributing to adaptation of the organism to stressful environmental encounters.