On a dinosaur axis from one of the oldest dinosaur-bearing sites worldwide

The axial skeleton is proportionally underrepresented in the fossil record of early dinosaurs, when compared to other skeletal parts (e.g., pelvic girdle and hindlimb). For instance, the axis is poorly known in early dinosaurs, which precludes a better understanding of this important anatomical structure. Therefore, the present contribution fills an important gap with a description of the axis of a new early dinosaur (CAPPA/UFSM 0179). The specimen was collected at the Buriol outcrop, a Triassic fossiliferous locality from southern Brazil (Candelária Sequence, Santa Maria Supersequence) biostratigraphically correlated to Carnian units, placing this specimen among the oldest dinosaurs worldwide. Notable features include the combination of a neural spine that bears an almost straight dorsal margin along its length and presence of an epipophysis. This axis arrangement is unique among Carnian dinosaurs, representing a new morphotype, though a similar morphology is observed in some early theropods. Indeed, a phylogenetic analysis nested the specimen within Theropoda. However, this outcome is probably biased by the large amount of missing data in CAPPA/UFSM 0179 and also due to the limited sampling of the axis in early dinosaurs, particularly among sauropodomorphs. As the specimen comes from the site that includes Buriolestes schultzi (an early sauropodomorph), it is quite plausible that CAPPA/UFSM 0179 might be referable to that taxon. If so, the specimen improves the anatomical knowledge of Buriolestes schultzi, given its axis is yet unknown. An alternative possibility to be considered is that the specimen would belong to a dinosaur not yet known in the Candelária Sequence, which would increase its dinosaur diversity for the outcrop, improving the Triassic dinosaurian record from Southern Brazil

Multifactorial causes of chronic mortality in juvenile sturgeon (Huso huso)

This investigation focused on an episode of chronic mortality observed in juvenile Huso huso sturgeons. The examined subjects underwent pathological, microbiological, molecular, and chemical investigations. Grossly severe body shape deformities, epaxial muscle softening, and multifocal ulcerative dermatitis were the main observed findings. The more constant histopathologic findings were moderate to severe rarefaction and disorganization of the lymphohematopoietic lymphoid tissues, myofiber degeneration, atrophy and interstitial edema of skeletal epaxial muscles, and degeneration and atrophy of the gangliar neurons close to the myofibers. Chemical investigations showed a lower selenium concentration in affected animals, suggesting nutritional myopathy. Other manifestations were nephrocalcinosis and splenic vessel wall hyalinosis. Septicemia due to bacteria such as Aeromonas veronii, Shewanella putrefaciens, Citrobacter freundii, Chryseobacterium sp., and pigmented hyphae were found. No major sturgeon viral pathogens were detected by classical methods. Next-generation sequencing (NGS) analysis confirmed the absence of viral pathogens, with the exception of herpesvirus, at the order level; also, the presence of Aeromonas veronii and Shewanella putrefaciens was confirmed at the family level by the metagenomic classification of NGS data. In the absence of a primary yet undetected biological cause, it is supposed that environmental stressors, including nutritional imbalances, may have led to immune system impairment, facilitating the entry of opportunistic bacteria and mycotic hyphae

Increases in sampling support the southern Gondwanan hypothesis for the origin of dinosaurs

Dinosaurs were ubiquitous in terrestrial ecosystems through most of the Mesozoic and are still diversely represented in the modern fauna in the form of birds. Recent efforts to better understand the origins of the group have resulted in the discovery of many new species of early dinosaurs and their closest relatives (dinosauromorphs). In addition, recent re-examinations of early dinosaur phylogeny have highlighted uncertainties regarding the interrelationships of the main dinosaur lineages (Sauropodomorpha, Theropoda and Ornithischia), and questioned the traditional hypothesis that the group originated in South Gondwana and gradually dispersed over Pangaea. Here, we use a historical approach to examine the impact of new fossil discoveries and changing phylogenetic hypotheses on biogeographic scenarios for dinosaur origins over 20 years of research time, and analyse the results in the light of different fossil record sampling regimes. Our results consistently optimize South Gondwana as the ancestral area for Dinosauria, as well as for more inclusive clades including Dinosauromorpha, and show that this hypothesis is robust to increased taxonomic and geographic sampling and divergent phylogenetic results. Our results do not find any support for the recently proposed Laurasian origin of dinosaurs and suggest that a southern Gondwanan origin is by far the most plausible given our current knowledge of the diversity of early dinosaurs and non-dinosaurian dinosauromorphs

Organogenesis and embryogenesis in several hypericum perforatum genotypes

St John’s wort (Hypericum perforatum) is a valuable plant used as a herbal remedy or in phytopharmaceutical drugs to treat a variety of physical ailments. Much research has been performed to study the biochemical production of secondary metabolites of in vitro cultured plants or organs. However, all of these studies have looked at the regeneration of plants from explants in only one genotype. In addition, no study has revealed the mechanism of plant regeneration in H. perforatum, i.e. organogenesis or somatic embryogenesis. We found that different genotypes Helos, Topas, Elixir, and Numi responded similarly to regeneration medium. The regeneration responses (i.e. callus, root, or shoot production) of identical explants from different genotypes were similar. However, the source of explant material (leaves, hypocotyls, and roots) from the same genotype had significant effects on the response to media and plant regeneration frequency. Using scanning electron microscopy and light microscopy, the progress of organogenesis and embryogenesis under similar culture conditions was recorded. Root segments were the most responsive explants, producing the maximum number of shoots per explant of all the genotypes.Fundação para a Ciência e a Tecnologia (FCT) - POCTI/AGR/40 283/2001, SFRH/BPD/17102/2004

Building an Aerial-Ground Robotics System for Precision Farming: An Adaptable Solution

[No abstract available

Cytosolic SYT/SS18 Isoforms Are Actin-Associated Proteins that Function in Matrix-Specific Adhesion

SYT (SYnovial sarcoma Translocated gene or SS18) is widely produced as two isoforms, SYT/L and SYT/S, that are thought to function in the nucleus as transcriptional coactivators. Using isoform-specific antibodies, we detected a sizable pool of SYT isoforms in the cytosol where the proteins were organized into filamentous arrays. Actin and actin-associated proteins co-immunoprecipitated with SYT isoforms, which also co-sedimented and co-localized with the actin cytoskeleton in cultured cells and tissues. The association of SYT with actin bundles was extensive yet stopped short of the distal ends at focal adhesions. Disruption of the actin cytoskeleton also led to a breakdown of the filamentous organization of SYT isoforms in the cytosol. RNAi ablation of SYT/L alone or both isoforms markedly impaired formation of stress fibers and focal adhesions but did not affect formation of cortical actin bundles. Furthermore, ablation of SYT led to markedly impaired adhesion and spreading on fibronectin and laminin-111 but not on collagen types I or IV. These findings indicate that cytoplasmic SYT isoforms interact with actin filaments and function in the ability cells to bind and react to specific extracellular matrices

A new structural framework for integrating replication protein A into DNA processing machinery

By coupling the protection and organization of single-stranded DNA (ssDNA) with recruitment and alignment of DNA processing factors, replication protein A (RPA) lies at the heart of dynamic multi-protein DNA processing machinery. Nevertheless, how RPA coordinates biochemical functions of its eight domains remains unknown. We examined the structural biochemistry of RPA’s DNA-binding activity, combining small-angle X-ray and neutron scattering with all-atom molecular dynamics simulations to investigate the architecture of RPA’s DNA-binding core. The scattering data reveal compaction promoted by DNA binding; DNA-free RPA exists in an ensemble of states with inter-domain mobility and becomes progressively more condensed and less dynamic on binding ssDNA. Our results contrast with previous models proposing RPA initially binds ssDNA in a condensed state and becomes more extended as it fully engages the substrate. Moreover, the consensus view that RPA engages ssDNA in initial, intermediate and final stages conflicts with our data revealing that RPA undergoes two (not three) transitions as it binds ssDNA with no evidence for a discrete intermediate state. These results form a framework for understanding how RPA integrates the ssDNA substrate into DNA processing machinery, provides substrate access to its binding partners and promotes the progression and selection of DNA processing pathways

EGFR interacts with the fusion protein of respiratory syncytial virus strain 2-20 and mediates infection and mucin expression.

Respiratory syncytial virus (RSV) is the major cause of viral lower respiratory tract illness in children. In contrast to the RSV prototypic strain A2, clinical isolate RSV 2-20 induces airway mucin expression in mice, a clinically relevant phenotype dependent on the fusion (F) protein of the RSV strain. Epidermal growth factor receptor (EGFR) plays a role in airway mucin expression in other systems; therefore, we hypothesized that the RSV 2-20 F protein stimulates EGFR signaling. Infection of cells with chimeric strains RSV A2-2-20F and A2-2-20GF or over-expression of 2-20 F protein resulted in greater phosphorylation of EGFR than infection with RSV A2 or over-expression of A2 F, respectively. Chemical inhibition of EGFR signaling or knockdown of EGFR resulted in diminished infectivity of RSV A2-2-20F but not RSV A2. Over-expression of EGFR enhanced the fusion activity of 2-20 F protein in trans. EGFR co-immunoprecipitated most efficiently with RSV F proteins derived from "mucogenic" strains. RSV 2-20 F and EGFR co-localized in H292 cells, and A2-2-20GF-induced MUC5AC expression was ablated by EGFR inhibitors in these cells. Treatment of BALB/c mice with the EGFR inhibitor erlotinib significantly reduced the amount of RSV A2-2-20F-induced airway mucin expression. Our results demonstrate that RSV F interacts with EGFR in a strain-specific manner, EGFR is a co-factor for infection, and EGFR plays a role in RSV-induced mucin expression, suggesting EGFR is a potential target for RSV disease