A revision of Prolimulus woodwardi Fritsch, 1899 with comparison to other highly paedomorphic belinurids

Xiphosurida is an ingroup of marine Euchelicerata often referred to as “living fossils”. However, this oxymoronic term is inapplicable for Paleozoic and early Mesozoic forms, as during these periods the group experienced notable evolutionary radiations; particularly the diverse late Palaeozoic clade Belinurina. Despite the iconic nature of the group, select species in this clade have been left undescribed in the light of recent geometric morphometric and phylogenetic considerations and methodologies. To this end, we re-describe Prolimulus woodwardi Fritsch, 1899 using new and type specimens to reveal more details on appendage anatomy and possible ecology. Furthermore, we present geometric morphometric and phylogenetic analyses that uncover relationships between P. woodwardi and other belinurids without genal spines. Both approaches highlight that a clade containing Prolimulus Fritsch, 1899, Liomesaspis Raymond, 1944, Alanops Racheboeuf, Vannier & Anderson, 2002 and Stilpnocephalus Selden, Simonetto & Marsiglio, 2019 may exist. While we do not erect a new group to contain these genera, we note that these genera exemplify the extreme limits of the Belinurina radiation and a peak in horseshoe crab diversity and disparity. This evidence also illustrates how changes in heterochronic timing are a key evolutionary phenomenon that can drive radiations among animals

Revision of “Bellinurus” carteri (Chelicerata: Xiphosura) from the Late Devonian of Pennsylvania, USA

Horseshoe crabs are an iconic group of marine chelicerates that have an impressive fossil record extending back to at least the Lower Ordovician. Despite their long fossil record and associated palaeontological interest, a range of fossil horseshoe crab taxa erected in the 19th and 20th centuries have remained understudied. Recent phylogenetic hypotheses have led to improvements in the understanding of xiphosuran origins and evolutionary history; however, the resolution among the basal-most Devonian-aged members remains poor. Here, the type specimen of “Bellinurus” carteri Eller, 1940 from the Late Devonian of Pennsylvania is reconsidered. Based on a revised morphological description and comparison, we conclude that the species is not referable to the genus Bellinurus and erected a new genus: Pickettia gen. nov. A phylogenetic analysis resolves Pickettia carteri within a polytomy containing taxa previously considered to comprise the group Kasibelinuridae, but which is currently a paraphyletic assemblage. We discuss P. carteri within the context of other stem xiphosurids and conclude that the diversity of this assemblage has been overstated. The redescription of P. carteri highlights the need for more inclusive studies to resolve the evolutionary relationships of stem xiphosurids

Incidence of non-01 Vibrio cholerae and Aeromonas spp. in fresh water in Araraquara, Brazil

The occurrence of Aeromonas spp., Vibrio cholerae, and Plesiomonas shigelloides in fresh water from various sources in Araraquara, State of São Paulo, Brazil was determined. Samples from ten distinct irrigation systems used in vegetable cultivation, from five distinct streams, from two reservoirs, from one artificial lake, and from three distinct springs were analyzed. All isolates were serotyped and tested for hemolysin, cytotoxin, heat-stable (ST) and heat-labile (LT) enterotoxins production; presence of plasmid; autoagglutination and drug resistance. V. cholerae isolates were also tested for cholera enterotoxin (CT) production, and Aeromonas isolates for suicide phenomenon. No P. shigelloides was found. V. cholerae non 01 was found in five irrigation water samples and in three stream samples. Aeromonas sp. were isolated in two samples of irrigation water, in three streams, and in one reservoir. All the V. cholerae and Aeromonas isolates were positive for P-hemolysin production, and all Aeromonas isolates were positive for suicide phenomenon; cytotoxic activities were observed in two Aeromonas strains. Cholera enterotoxin was not found in eight V. cholerae non-01 isolates tested by the Y-1 mouse adrenal cell. All isolates were also negative for the other virulence markers. Ii cholelerae isolates were found to be sensitive to the majority of drugs tested, while Aeromonas strains presented multiple drug resistance.

Individual error correction drives responsive self-assembly of army ant scaffolds

An inherent strength of evolved collective systems is their ability to rapidly adapt to dynamic environmental conditions, offering resilience in the face of disruption. This is thought to arise when individual sensory inputs are filtered through local interactions, producing an adaptive response at the group level. To understand how simple rules encoded at the individual level can lead to the emergence of robust group-level (or distributed) control, we examined structures we call "scaffolds," self-assembled by Eciton burchellii army ants on inclined surfaces that aid travel during foraging and migration. We conducted field experiments with wild E. burchellii colonies, manipulating the slope over which ants traversed, to examine the formation of scaffolds and their effects on foraging traffic. Our results show that scaffolds regularly form on inclined surfaces and that they reduce losses of foragers and prey, by reducing slipping and/or falling of ants, thus facilitating traffic flow. We describe the relative effects of environmental geometry and traffic on their growth and present a theoretical model to examine how the individual behaviors underlying scaffold formation drive group-level effects. Our model describes scaffold growth as a control response at the collective level that can emerge from individual error correction, requiring no complex communication among ants. We show that this model captures the dynamics observed in our experiments and is able to predict the growth-and final size-of scaffolds, and we show how the analytical solution allows for estimation of these dynamics.publishe

Chemical, spectroscopic characterization, and in vitro antibacterial studies of a new gold(I) complex with N-acetyl-L-cysteine

A new gold(I) complex with N-acetyl-L-cysteine was synthesized and characterized by chemical and spectroscopic techniques. The elemental and thermal analyses of the solid compound fit to the composition AuC5H8NO3S center dot 0.75H2O. Solid-state 13C-nuclear magnetic resonance (SSNMR) and infrared (IR) analyses indicate the coordination of the ligand to Au(I) through sulfur. The insolubility of the complex in both polar and non-polar solvents supports a polymeric structure. The antibacterial activity of the complex was evaluated by antibiogram assays using the disc diffusion method. The compound showed effective antibacterial activity against Staphylococcus aureus (Gram positive) and Escherichia coli (Gram negative) bacterial cells.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Palladium(ii) Complex With S-allyl-l-cysteine: New Solid-state Nmr Spectroscopic Measurements, Molecular Modeling And Antibacterial Assays.

Nuclear magnetic resonance studies, molecular modeling and antibacterial assays of the palladium(II) complex with S-allyl-L-cysteine (deoxyalliin) are presented. Studies based on solid and solution 13C and 15N nuclear magnetic resonance (NMR) spectroscopy confirmed that the palladium(II) complex preserved the same structural arrangement in both states, with no modifications on coordination sphere when dissolved in water. Density functional theory (DFT) studies stated that the trans isomer is the most stable one. Antibacterial activities of S-allyl-L-cysteine and its palladium(II) complex were evaluated by antibiogram assays using the disc diffusion method. The palladium(II) complex showed an effective antibacterial activity against Staphylococcus aureus (Gram-positive), Escherichia coli and Pseudomonas aeruginosa (Gram-negative) bacterial cells.78313-