Basal Position Research Articles

Synthesis, structure, and solution chemistry of mixed-ligand oxidovanadium(IV) complexes incorporating ONO donor hydrazone ligands

Four mixed-ligand oxidovanadium(IV) complexes, [VIVO(L1-4)(phen)], 1-4, incorporating tridentate dibasic ONO donor hydrazone ligands (H2L1-4, general abbreviation H2L) derived from the condensation of 2-picolinyl hydrazide with 2-hydroxy acetophenone and its 5-substituted derivatives as primary ligands and 1,10-phenanthroline (phen) as auxiliary ligand have been synthesized in excellent yields. The complexes were characterized by elemental analyses, magnetic susceptibility measurements, and various spectral (e.g. IR, UV–Vis and EPR) studies. The molecular structure of one of the four complexes has been determined by single-crystal X-ray diffractometry. In 1, the hydrazone ligand is meridionally disposed of, coordinating through one enolic-O, one phenolic-O, and one imine-N. The other basal position is occupied by one pyridine-N of the phen moiety. The axial positions are occupied by one oxido-O atom and the other pyridine-N atom of the phen moiety. The complexes are paramagnetic with one unpaired electron (μeff ≈ 1.73 BM), suggesting no interaction with the neighboring molecules and are EPR active. The complexes display two d-d transitions, one near 725 and the other near 840 nm due to d xy → d xz , d yz and d xy → d x 2 − y 2 transitions, respectively. The other d-d transition associated with d xy → d z 2 transition was not observed as it falls in the UV region, which is masked by highly intense intra-ligand transitions. The complexes display one-electron oxidation peaks in the +0.75 to +0.89 V vs. Ag/AgCl region in the CH3CN solution that show a linear relationship with the Hammett parameter (σ) of the substituents in the aryloxy ring.

MpPUB9, a U-box E3 ubiquitin ligase, acts as a positive regulator by promoting the turnover of MpEXO70.1 under high salinity in Marchantia polymorpha.

Marchantia polymorpha, occupying a basal position in the monophyletic assemblage of land plants, displays a notable expansion of plant U-box (PUB) proteins compared with those in animals. We elucidated the roles of MpPUB9 in regulating salt stress tolerance in M. polymorpha. MpPUB9 expression was rapidly induced by high salinity and dehydration. MpPUB9 possessed an intact U-box domain in the N-terminus. MpPUB9-Citrine localized to punctate structures and was peripherally associated with microsomal membranes. Phenotypic analyses demonstrate that the hyponastic and epinastic thallus growth phenotypes, which were induced by the overexpression and suppression of MpPUB9, may provoke salt stress-resistant and -susceptible phenotypes, respectively. MpPUB9 was also found to directly interact with the exocyst protein MpEXO70.1, leading to its ubiquitination. Under high-salinity conditions, though the stability of MpPUB9 was dramatically increased, MpEXO70.1 showed slightly faster turnover rates. Transcriptome analyses showed that salt treatment and the overexpression of MpPUB9 co-upregulated the genes related to the modulation of H2O2 and cell wall organization. Overall, our results suggest that MpPUB9 plays a crucial role in the positive regulation of salt stress tolerance, resulting from its interaction with MpEXO70.1 and modulating turnover of the protein under high-salt conditions via the coordination of UPS with autophagy.

Museum specimens shedding light on the evolutionary history and cryptic diversity of the hedgehog family Erinaceidae.

The family Erinaceidae encompasses 27 extant species in two subfamilies: Erinaceinae, which includes spiny hedgehogs, and Galericinae, which comprises silky-furred gymnures and moonrats. Although they are commonly recognized by the general public, their phylogenetic history remains incompletely understood, and several species have never been included in any molecular analyses. Additionally, previous research suggested that the species diversity of Erinaceidae might be underestimated. In this study, we sequenced the mitochondrial genomes of 29 individuals representing 18 erinaceid species using 18 freshly collected tissue and 11 historical museum specimens. We also integrated previously published data for a concatenated analysis. We aimed to elucidate the evolutionary relationships within Erinaceidae, estimate divergence times, and uncover potential underestimated species diversity. Our data finely resolved intergeneric and interspecific relationships and presented the first molecular evidence for the phylogenetic position of Mesechinus wangi, Paraechinus micropus, and P. nudiventris. Our results revealed a sister relationship between Neotetracus and Neohylomys gymnures, as well as a sister relationship between Hemiechinus and Mesechinus, supporting previous hypotheses. Additionally, our findings provided a novel phylogenetic position for Paraechinus aethiopicus, placing it in a basal position within the genus. Furthermore, our study uncovered cryptic species diversity within Hylomys suillus as well as in Neotetracus sinensis, Atelerix albiventris, P. aethiopicus, and Hemiechinus auratus, most of which have been previously overlooked.

Phylogeography and population genetics of the endemic Italian water voles, Arvicola italicus

The genus Arvicola has a wide palearctic distribution and present two ecological forms – terrestrial and aquatic – characterizing the genus. In Europe two species are present: the most widespread, A. amphibius and A. italicus, endemic to Italy. The aim of the study was to describe the genetic structure and variability in A. italicus and the genetic identity of populations in northeast Italy, an area of biogeographic importance as contact zone for small mammal species.Thirty-six Italian water voles, displaced in population from south to north of Italy, were analyzed by two mitochondrial markers and 8 autosomal microsatellite loci. The phylogenetic analysis on the genus confirmed the presence of major groups mostly corresponding to the species and clades already described. About the Italian specimens, the individuals from one population in northeastern Italy resulted included in A. amphibius revealing the presence of this species in Italy and, in consequence, the possible presence of a putative contact zone between A. italicus and A. amphibius in the northeast. The phylogeny includes a second population from northeast Italy within A. amphibius, but in basal position and with a low support. The values of divergence of this lineage from A. italicus and A. amphibius lie on the threshold between intraspecific and interspecific divergence. Conversely, microsatellite data support a clear distinction between A. amphibius and A. italicus and includes the ambiguous mitochondrial lineage in this latter species. Furthermore, this northeastern population shows evidence of admixture of nuclear loci with the southcentral A. italicus populations, supporting the attribution of these specimens to A. italicus. This pattern could suggest that A. italicus in northeast Italy retained an ancestral haplotype and undergone a long period of isolation respect to the southern populations, without genetic exchange until recent times. Within A. italicus, the admixture shows northern population as the most differentiated showing limited evidence of admixture with the most diverse southcentral. The intraspecific diversity decreases from south to north as expected for an endemic small mammal in Italy. Finally, the low genetic diversity observed in the northern population can be challenging for a species as Arvicola living in fragmented habitats and susceptible to habitat loss; consequently, became important identifying suitable conservation measures for this barely known endemic small mammal.

Characterization of the complete mitochondrial genome of Loxocephala sichuanensis (Hemiptera: Eurybrachidae) with the phylogenetic analyses of Fulgoromorpha

Little is known about the mitochondrial genome of the family Eurybrachidae, with only two species sequenced. This study added one more mitogenome of Loxocephala sichuanensis in this family. The mitochondrial genome length of this species was 15,605 bp, consisting of 37 genes: 13 PCGs, 2 rRNAs, 22 tRNAs, and a control region. An unusually high A + T content, reaching 94.3% at the third codon position of 13 PCGs in Loxocephala, was found in Eurybrachidae, which was the highest among all planthoppers, especially on N-strand. Three tandem repeat regions were detected in the control region. Phylogenetic analyses based on complete mitochondrial genome sequences from 145 species (encompassing 18 planthopper families and 135 species in Fulgoromorpha as ingroup, and 6 other non-planthopper families in Auchenorrhyncha as outgroup) were conducted. Six datasets (PCG123R24, PCG123R2, PCG123, PCG12R24, PCG12R2, PCG12) were established to investigate the influence of 22 tRNAs and the third codon of the 13 PCGs of mitogenome for phylogeny analyses. Both Maximum likelihood and Bayesian trees supported the monophyly of the superfamilies Delphacoidea and Fulgoroidea. Delphacoidea, consisting of Cixiidae and Delphacidae as sister group, was in the basal position of Fulgoromorpha. In Fulgoroidea, the families Meenoplidae and Kinnaridae, Dictyopharidae and Fulgoridae, Acanaloniidae and Tropiduchidae were sister groups which were strongly supported. Caliscelidae was close to the sister group Lophopidae with Eurybrachidae. The four families Flatidae, Nogodinidae, Ricaniidae and Issidae were closely related. The position of Tettigometridae was uncertain. Derbidae and Achilidae form a sister group when 22 tRNAs were included in the phylogeny. The joining of the tRNA sequences of mitochondrial genome enhanced the stability of family-level nodes and adjusted some phylogenetic positions, highlighting the significant role of joining tRNAs in phylogenetic analyses. Including or excluding the third codon position of 13 PCGs generally did not affect the overall phylogenetic structures of Fulgoromorpha.

The Oldest Swallow (Aves: Passeriformes: Hirundinidae) from the Upper Lower Miocene of Southeastern Siberia.

A new genus and species of fossil swallows, Miochelidon eschata gen. et sp. nov., are described from the Lower Miocene of the Baikal region. This is the only Miocene representative of Hirundinidae and the oldest fossil record of the group. The coracoid of Miochelidon combines generalized and specialized features, suggesting a basal position in the family for the genus. The ulna has a more advanced morphology, like in modern swallows. The find indicates a widespread distribution of basal swallows in the Early Miocene.

Phylogenetic synthesis of morphological and molecular data reveals insights on the classification of diogenid hermit crabs (Crustacea: Decapoda: Anomura).

The family Diogenidae Ortmann, 1892 is a diverse and abundance group of hermit crabs, but their systematics and phylogenetic relationships are highly complex and unresolved. Herein, we gathered nucleotide sequence data from two mitochondrial (16S rRNA and COI) and two nuclear (NaK and PEPCK) genes for a total of 2,308 bp in length across 38 species from six extant diogenid genera. Molecular data were combined with 41 morphological characters to estimate the largest phylogeny of diogenid hermit crabs to date with the aim of testing the proposed taxonomic scheme of Diogenidae and addressing intergeneric relationships within this family. Despite conflicts between mitochondrial and nuclear DNA trees, the combined-data tree reflects the contributions of each dataset, and improves tree resolution and support for internal nodes. Contrary to traditional classification, our total evidence revealed a paraphyletic Diogenidae based on internally nested representatives of Coenobitidae Dana, 1851. Within Diogenidae, the studied diogenid hermit crabs were split between two clades with high support, which contradicts recent morphological classification scheme for Diogenidae sensu lato based on fossil records. The genus Diogenes Dana, 1851 was found nested inside Paguristes Dana, 1851, which formed a clade being separated from the remainder, pointing towards paraphyly in Paguristes. In another clade, Dardanus Paulson, 1875 occupied a basal position relative to the other diogenids, while Calcinus Dana, 1851 and Clibanarius Dana, 1852 showed sister relationships and formed a cluster with Ciliopagurus Forest, 1995. Among the morphological characters examined, carapace shield and telson were identified as phylogenetically significant for grouping diogenid genera, while phylogenetic insignificance of gill number was evidenced by its mosaic pattern in diogenid phylogeny. The present study sheds light on the controversial generic phylogeny of Diogenidae and highlights the necessity for thorough taxonomic revisions of this family as well as some genera (e.g., Paguristes) to reconcile current classifications with phylogenetic relationships.

Comprehensive analysis of the Lycopodium japonicum mitogenome reveals abundant tRNA genes and cis-spliced introns in Lycopodiaceae species.

Lycophytes and ferns represent one of the earliest-diverging lineages of vascular plants, with the Lycopodiaceae family constituting the basal clade among lycophytes. In this research, we successfully assembled and annotated the complete Lycopodium japonicum Thunb. (L. japonicum) mitochondrial genome (mitogenome) utilizing PacBio HiFi sequencing data, resulting in a single circular molecule with a size of 454,458 bp. 64 unique genes were annotated altogether, including 34 protein-coding genes, 27 tRNAs and 3 rRNAs. It also contains 32 group II introns, all of which undergo cis-splicing. We identified 195 simple sequence repeats, 1,948 dispersed repeats, and 92 tandem repeats in the L. japonicum mitogenome. Collinear analysis indicated that the mitogenomes of Lycopodiaceae are remarkably conserved compared to those of other vascular plants. We totally identified 326 RNA editing sites in 31 unique protein-coding genes with 299 sites converting cytosine to uracil and 27 sites the reverse. Notably, the L. japonicum mitogenome has small amounts foreign DNA from plastid or nuclear origin, accounting for only 2.81% of the mitogenome. The maximum likelihood phylogenetic analysis based on 23 diverse land plant mitogenomes and plastid genomes supports the basal position of lycophytes within vascular plants and they form a sister clade to all other vascular lineages, which is consistent with the PPG I classification system. As the first reported mitogenome of Lycopodioideae subfamily, this study enriches our understanding of Lycopodium mitogenomes, and sets the stage for future research on mitochondrial diversity and evolution within the lycophytes and ferns.

UCE-based phylogenomics of the lepidopteran endoparasitoid wasp subfamily Rogadinae (Hymenoptera: Braconidae) unveils a new Neotropical tribe.

During the past two decades, the phylogenetic relationships and higher-level classification of the subfamily Rogadinae have received relevant contributions based on Sanger, mitogenome and genome-wide nuclear DNA sequence data. These studies have helped to update the circumscription and tribal classification of this subfamily, with six tribes currently recognised (Aleiodini, Betylobraconini, Clinocentrini, Rogadini, Stiropiini and Yeliconini). The tribal relationships within Rogadinae, however, are yet to be fully resolved, including the status of tribe Facitorini, previously regarded as betylobraconine, with respect to the members of Yeliconini. We conducted a phylogenomic analysis among the tribes of Rogadinae based on genomic ultraconserved element (UCE) data and extensive taxon sampling including three undescribed genera of uncertain tribal placement. Our almost fully supported estimate of phylogeny confirmed the basal position of Rogadini within the subfamily and a Facitorini clade (Yeliconini+Aleiodini) that led us to propose the former group as a valid rogadine tribe (Facitorini stat. res.). Stiropiini, however, was recovered for the first time as sister to the remaining rogadine tribes except Rogadini, and Clinocentrini as sister to a clade with Betylobraconini+the three undescribed genera. The relationships recovered and morphological examination of the material included led us to place the latter three new genera and recently described genus Gondwanocentrus within a new rogadine tribe, Gondwanocentrini Shimbori & Zaldívar-Riverón trib. nov. We described these genera (Ghibli Shimbori & Zaldívar-Riverón gen. nov., Racionais Shimbori & Zaldívar-Riverón gen. nov. and Soraya Shimbori gen. nov.) with two or three new species each (G. miyazakii Shimbori & Zaldívar-Riverón sp. nov., G. totoro Shimbori & Zaldívar-Riverón sp. nov., R. brunus Shimbori & Zaldívar-Riverón sp. nov., R. kaelejay Shimbori & Zaldívar-Riverón sp. nov., R. superstes Shimbori & Zaldívar-Riverón sp. nov., S. alencarae Shimbori sp. nov. and S. venus Shimbori & Zaldívar-Riverón sp. nov.). A new species of Facitorini, Jannya pasargadae Gadelha & Shimbori sp. nov., is also described. Our newly proposed classification expands the number of tribes and genera within Rogadinae to 8 and 66 respectively. ZooBank: urn:lsid:zoobank.org:pub:51951C78-069A-4D8B-B5F0-7EBD4D9D21CE.

Genomic diversity and analysis of resistance determinants of <i>Salmonella enterica</i> subspecies <i>enterica</i> serotype Kentucky isolated in Russia

Introduction. Salmonella Kentucky sequence type ST198 is one of the epidemiologically significant non-typhoidal Salmonella clones worldwide and is characterized by the presence of highly resistant strains and the ability to adapt to different animal hosts and environmental conditions. The aim of this study was to analyze S. Kentucky strains isolated from various sources in Russia in terms of their phylogenetic position within the global diversity of the pathogen and their genetic characteristics. Materials and methods. We examined 55 strains of S. Kentucky by whole-genome sequencing, which were isolated from 2010 to 2022 from various sources (clinical strains, food, as well as from farm animals, feed and environmental samples). Whole genome sequencing was performed using Illumina platforms. Phylogenetic analysis based on nucleotide variation analysis included an additional 390 S. Kentucky strains. Results. Most of the Russian strains (n = 50) belonged to the ST198 sequence type, four strains were ST314 and one strain was ST152. Of the 50 Russian sequence-type ST198 strains, 44 belonged to the international monophyletic MDR lineage S. Kentucky ST198, and belonged to four separate sublineages, six strains occupying a basal position in relation to the MDR lineage. A total of 320 genes and mutations responsible for resistance to antimicrobial agents were identified. The most common were point mutations in the QRDR region. In most cases, Russian strains were characterized by the presence of variants of the SGI1-K genomic island. Moreover, the putative structure of SGI1 was correlated with the phylogenetic clustering of S. Kentucky sublineages. Conclusions. The results of the study made it possible to assess the population structure of Russian S. Kentucky ST198 strains on a global scale and determine the genetic determinants of antibiotic resistance, including the structure of the SGI1 genomic island.

The complete chloroplast genome sequence of Viola labradorica (Violaceae)

Viola labradorica is commonly known as Alpine violet, American dog violet, Dog violet, and Labrador violet. This species is distributed throughout eastern Canada and North America. In the present study, we sequenced the chloroplast genome of V. labradorica for the first time and performed a phylogenetic analysis of the genus Viola. The length of the chloroplast genome of V. labradorica was 158,751 bp. A large single-copy region (87,211 bp), a small single-copy region (17,344 bp), and two inverted repeat regions (27,098 bp each) were identified. A phylogenetic analysis was conducted using 77 protein-coding genes from the chloroplast genomes of 34 Viola. Salix koriyanagi (Salicaceae) was used as an outgroup. The genus Viola forms a monophyletic clade. Among the clades for the genus Viola, the sect. Viola formed a clade and was divided into two subclades: subsect. Viola and subsect. Rostratae. Within the subsect. Rostratae, V. labradorica was placed in a basal position. These results contribute to a clear identification of the phylogenetic position of V. labradorica in the subsect. Rostratae.

Phylogenetic Analysis of the Genes in D-Ala-D-Lactate Synthesizing Glycopeptide Resistance Operons: The Different Origins of Functional and Regulatory Genes.

The phylogenetic relationships of glycopeptide resistance proteins were investigated. The amino acid sequences of vanA, vanB, vanR and vanS were used as queries to search against bacterial genomes in the NCBI RefSeq database. Hits with >60% amino acid identity and >90% query coverage were aligned, and phylogenetic trees were reconstructed. The ligase gene phylogenies were highly similar for both queries, revealing two major clusters. One contained [[vanA:vanM][vanB:vanD]vanF] and related proteins, with proteins from different Bacillaceae, mostly from Paenibacillus spp., in basal positions to all, except vanB. Ligases from streptomycetes formed the other cluster. The relative positions of vanH and vanX differed from those of the associated ligases, but the basal position of the Paenibacillus spp. and the separation of proteins of Streptomyces origin were similar. The accessory genes vanW, vanY and vanZ were associated with vanB, vanA/vanM and vanA, respectively; the basal branches were always proteins from different Bacillaceae but never from streptomycetes. Multiple homologs of the regulatory genes vanR and vanS were found in the genomes; those associated with the different ligases were unique to the ligases. Similarly to the accessory genes, vanRS from Bacillales and Clostridia, but never from streptomycetes, was found in the basal positions. In conclusion, the core genes vanA/B/D/F/M, vanH and vanX originate most probably from glycopeptide-producing streptomycetes, with Paenibacillus spp. (or other Bacillaceae) mediating the transfer, while the accessory genes and the regulatory apparatus probably originate from these Bacillaceae.

Reproduction-associated pathways in females of gibel carp (Carassius gibelio) shed light on the molecular mechanisms of the coexistence of asexual and sexual reproduction

Gibel carp (Carassius gibelio) is a cyprinid fish that originated in eastern Eurasia and is considered as invasive in European freshwater ecosystems. The populations of gibel carp in Europe are mostly composed of asexually reproducing triploid females (i.e., reproducing by gynogenesis) and sexually reproducing diploid females and males. Although some cases of coexisting sexual and asexual reproductive forms are known in vertebrates, the molecular mechanisms maintaining such coexistence are still in question. Both reproduction modes are supposed to exhibit evolutionary and ecological advantages and disadvantages. To better understand the coexistence of these two reproduction strategies, we performed transcriptome profile analysis of gonad tissues (ovaries) and studied the differentially expressed reproduction-associated genes in sexual and asexual females. We used high-throughput RNA sequencing to generate transcriptomic profiles of gonadal tissues of triploid asexual females and males, diploid sexual males and females of gibel carp, as well as diploid individuals from two closely-related species, C. auratus and Cyprinus carpio. Using SNP clustering, we showed the close similarity of C. gibelio and C. auratus with a basal position of C. carpio to both Carassius species. Using transcriptome profile analyses, we showed that many genes and pathways are involved in both gynogenetic and sexual reproduction in C. gibelio; however, we also found that 1500 genes, including 100 genes involved in cell cycle control, meiosis, oogenesis, embryogenesis, fertilization, steroid hormone signaling, and biosynthesis were differently expressed in the ovaries of asexual and sexual females. We suggest that the overall downregulation of reproduction-associated pathways in asexual females, and their maintenance in sexual ones, allows the populations of C. gibelio to combine the evolutionary and ecological advantages of the two reproductive strategies. However, we showed that many sexual-reproduction-related genes are maintained and expressed in asexual females, suggesting that gynogenetic gibel carp retains the genetic toolkits for meiosis and sexual reproduction. These findings shed new light on the evolution of this asexual and sexual complex.

A new basal hupehsuchian from the Early Triassic of South China and its implication to the phylogenetic relationships of Ichthyosauromorpha (Reptilia: Diapsida)

ABSTRACT The endemic Hupehsuchia from the Early Triassic of South China is generally accepted as the sister group of ichthyosauriforms and represents the only ichthyosauromorph that lived mainly in the shallow aquatic environment. Therefore, the detailed morphological study of basal hupehsuchians is important to elucidate the relationships of Ichthyosauromorpha with other reptiles. However, Nanchangosaurus, the most basal hupehsuchian taxon, is represented by only two skeletons, and the morphology of its palate and most of the appendicular skeleton remains unknown, limiting its role in resolving the phylogenetic relationships of Ichthyosauromorpha. Here we report a new hupehsuchian specimen from the Early Triassic of South China, which we have identified as a new morphotype of Nanchangosaurus. The new skeleton shows for the first time the morphology of the palate, zeugopodium and autopodium in Nanchangosaurus. Phylogenetic analyses including new morphological information from this skeleton support the recent recovery of an aquatic clade that includes the three major Triassic marine reptile groups. A clade comprising Helveticosaurus and Sauropterygomorpha forms the sister group to Ichthyosauromorpha, and Thalattosauria occupies the most basal position in this large aquatic clade. Archosauromorpha is recovered as a sister group to this aquatic clade, and together they form part of a monophyletic Archelosauria.

Assessing V6 RWPT and V6-V1 interpeak time as conduction system capture criteria in non-basal LBBAP lead positions

Abstract Background In left bundle branch area pacing(LBBAP) a basal septal lead position is usually aimed for. However, in clinical practice LBBAP leads might be implanted in a non-basal position. A basal lead position is characterized by a paced monophasic R-wave in lead V6, whereas a non-basal position leads to a paced Rs/rS pattern in lead V6(1). Because differences in interval from pacing stimulus to peak R-wave in lead V6(V6 RWPT) and interval between peak R-wave in lead V6 and lead V1(V6-V1 interpeak time) in non-basal positions might be observed, it is unclear if the current cut-off values for these intervals can be used for conduction system capture(CSC) verification in non-basal placed LBBAP leads. Purpose To investigate the differences in paced V6 RWPT and V6-V1 interpeak time between basally and non-basally implanted LBBAP leads and to identify optimal cut-off values for CSC verification in non-basally implanted LBBAP leads. Methods Patients implanted with an LBBAP lead were retrospectively screened and included when a paced Rs/rS was demonstrated in lead V6 >20%(1) of the total QRS amplitude. A random selection of LBBAP patients without a paced Rs/rS in lead V6 implanted in the same period were included as comparator. CSC was confirmed by an output-dependent QRS transition at decremental voltage output pacing or an interval from the left-sided Purkinje potential to V6RWPT in intrinsic rhythm equal to paced V6RWPT. If none of these were present, left ventricular septal pacing was assumed. Results Eighty patients were included for analyses. Baseline characteristics are presented in fig. 1. Patients with non-basally implanted LBBAP leads were significantly younger(p=0.004) and showed a significantly shorter interval from left-sided Purkinje potential to QRS onset(p=0.041). Paced V6RWPT was significantly shorter in a non-basal lead position (70±12ms vs. 77±9ms, p=0.005), fig 2A. V6-V1 interpeak time was significantly longer in non-basal lead positions(52±14ms vs. 40±9 ms, p<0.001), fig 2A. A V6RWPT cut-off <70ms(sens. 78%, spec. 83%, AUC 0.79) was optimal for CSC confirmation in non-basal lead positions with 100% specificity achieved <55ms. A V6-V1 interpeak time cut-off >47ms(sens. 74%, spec. 65%, AUC 0.73) was optimal for CSC capture confirmation with 100% specificity achieved >73ms, fig 2b. Conclusion The interval from left-sided Purkinje potential to QRS onset in patients with a paced Rs/rS in lead V6 is significantly shorter than in patients with a paced monophasic R in lead V6, suggesting a more distal lead position. This lead position leads to significant shortening of V6 RWPT and prolongation of V6-V1 interpeak time, affecting known diagnostic criteria for conduction system capture. An optimal cut-off <70 ms and 100% specificity <55ms for conduction system capture confirmation with V6 RWPT is suggested. An optimal cut-off >47ms and 100% specificity >73ms for conduction system capture confirmation with V6-V1 interpeak time is suggested.

Phylogenetic position of Kinnareemimus khonkaenensis (Dinosauria: Theropoda: Ornithomimosauria) from the Lower Cretaceous of Thailand

A small-bodied ornithomimosaur, Kinnareemimus khonkaenensis Buffetaut, Suteethorn, and Tong 2009, from the Lower Cretaceous Sao Khua Formation of northeastern Thailand was first reported in 1995, then named in 2009. It is the only report of this group in Southeast Asia and was concluded to be a member of Ornithomimosauria, more derived than Harpymimus and Garudimimus but more basal than Archaeornithomimus. Since then, a few published studies have analyzed the phylogenetic position of Kinnareemimus but failed to find it within the clade Ornithomimosauria. Here, the phylogenetic analyses for assessing the relationships of Kinnareemimus within Ornithomimosauria were performed. The results suggested it might be a basal ornithomimosaur or belongs to the subclade Deinocheiridae. Kinnareemimus shares with deinocheirids the proximally projected cnemial crest and the shape of the fibula in proximal view. Its metatarsal III shows subarctometatarsalian condition with metatarsal III pinched between II and IV but visible in anterior view proximally, which might have evolved independently from other ornithomimids. However, the basal position of Kinnareemimus could also be due to the immaturity and the incomplete nature of this animal.

Left bundle branch area pacing improves right ventricular function and synchrony

BackgroundThe impact of left bundle branch area pacing (LBBAP) on right ventricular (RV) function and tricuspid regurgitation (TR) remains unclear. ObjectiveWe aimed to assess the long-term effects of LBBAP on RV performance and on TR. MethodsRV function was evaluated using RV free wall strain, tricuspid annular plane systolic excursion, fractional area changing, and systolic velocity of the lateral tricuspid annulus. The presence of reverse septal flash (RSF) and basal bulge (BB) was used to assess RV motion pattern. The distance between the lead entry site on the interventricular septum and the septal leaflet of the tricuspid annulus (lead-TV distance) was measured. ResultsThe analysis included 122 subjects [62 men (50.8%); mean age 76.5 ± 11.4 years] with a median follow-up of 21 months (18–24.5 months). During follow-up, RV free wall strain improved significantly (15.2 ± 5.8 vs 16.4 ± 5.5; P < .001) while tricuspid annular plane systolic excursion, systolic, and fractional area changing remained unchanged. Left ventricular ejection fraction was an independent predictor of improved RV function (B = 3.51; 95% confidence interval 1.39–8.9; P = .01). With LBBAP, RSF disappeared in 22 of 23 patients (96%) and BB in 15 of 22 patients (68%) in whom RSF and BB were present at baseline, respectively. RV function improvement was significantly higher when RSF was present at baseline (14 patients vs 11 patients; P = .02). At follow-up, no significant deterioration in TR occurred for the overall group. However, a lead-TV distance of <24.5 mm was associated with TR progression. ConclusionLBBAP has a favorable impact on RV function. A basal LBBAP position is associated with worsening TR.

Morphological diversity of saber-tooth upper canines and its functional implications.

Elongated upper canine teeth, commonly known as saber-teeth, have evolved three times within the sub-order Feliformia. The species that wielded them flourished throughout the Cenozoic and have historically been separated into two morphological groups: the dirk-tooths with longer, flatter canines, and the scimitar-tooths with shorter, serrated teeth. However, quantitative morphological analysis has not been conducted on these teeth to determine the true amount of diversity within the group, and how the upper canine morphology of extant feliforms compared to their extinct relatives has also not been explored. Using Geometric Morphometric analysis, it is shown that saber-tooth upper canine morphology is exceptionally diverse, with no extant clade having all its members occupy the same morphospace based on tooth length and curvature. Instead, a neutral basal morphospace is observed for all groups and diversification from this basal position is seen as species become more derived. A distinct and consistent scimitar tooth morphology is also not observed within the morphospace. When compared with extant taxa, several saber-tooth species are seen to be morphologically similar to extant feliforms, several of which exhibit novel dietary strategies in comparison to the obligate carnivore felids. Biomechanical analyses of different actual and theoretical tooth shapes demonstrate that saber-teeth upper canines further represent a functional compromise between sharpness, curvature, and length on the one hand, and robustness and material investment on the other.

Exploring genital and pregenital musculature in Synthesiomyia nudiseta (Diptera: Muscidae: Reinwardtiinae): Insights into evolutionary relationships with subfamily Azeliinae

AbstractThe male genital, pregenital skeleton, musculature of male terminalia, and the ovipositor were studied in Synthesiomyia nudiseta (Wulp). A comparison was conducted between the terminal segments and muscles of S. nudiseta and previously studied species of the subfamily Azeliinae. Notable differences were found between previously studied species of the subfamily Azeliinae and Synthesiomyia + Muscina. These differences correspond to apomorphic character states in Synthesiomyia + Muscina, including the large size of the ejaculatory apodeme and the powerful constrictors of the ejaculatory apodeme M 23; the completely membranous sternite VI; the membrane connection of the muscle ISM 5 (lower); the small size of pregonites and postgonites; and the joints of the phallapodeme muscles М 21 at the base of the hypandrial arms. Based on these differences, Synthesiomyia + Muscina can be assigned to the subfamily Reinwardtiinae, as has been confirmed by recent molecular studies. However, similarities in the set of pregenital muscles and the set of phallapodeme muscles between Synthesiomyia + Muscina and the Azeliinae were also noted. These similarities may be considered as plesiomorphic character states, indicating their phylogenetic relationship. It can be argued that Reinwardtiinae + Azeliinae constitute sister groups and occupy the basal position within the family Muscidae.

Crocosphaera watsonii - A widespread nitrogen-fixing unicellular marine cyanobacterium.

Crocosphaera watsonii is a unicellular N2-fixing (diazotrophic) cyanobacterium observed in tropical and subtropical oligotrophic oceans. As a diazotroph, it can be a source of bioavailable nitrogen (N) to the microbial community in N-limited environments, and this may fuel primary production in the regions where it occurs. Crocosphaera watsonii has been the subject of intense study, both in culture and in field populations. Here, we summarize the current understanding of the phylogenetic and physiological diversity of C. watsonii, its distribution, and its ecological niche. Analysis of the relationships among the individual Crocosphaera species and related free-living and symbiotic lineages of diazotrophs based on the nifH gene have shown that the C. watsonii group holds a basal position and that its sequence is more similar to Rippkaea and Zehria than to other Crocosphaera species. This finding warrants further scrutiny to determine if the placement is related to a horizontal gene transfer event. Here, the nifH UCYN-B gene copy number from a recent synthesis effort was used as a proxy for relative C. watsonii abundance to examine patterns of C. watsonii distribution as a function of environmental factors, like iron and phosphorus concentration, and complimented with a synthesis of C. watsonii physiology. Furthermore, we have summarized the current knowledge of C. watsonii with regards to N2 fixation, photosynthesis, and quantitative modeling of physiology. Because N availability can limit primary production, C. watsonii is widely recognized for its importance to carbon and N cycling in ocean ecosystems, and we conclude this review by highlighting important topics for further research on this important species.