GROSS AND ULTRASONOGRAPHIC ANATOMY OF THE COELOMIC ORGANS OF HEALTHY AXOLOTLS (AMBYSTOMA MEXICANUM).

The objectives of this study were to describe the gross anatomy and ultrasonographic appearance of coelomic organs in subadult and adult axolotls (Ambystoma mexicanum), to describe an ultrasound technique, and to test correlations of ultrasonographic measurement with body length, width, and weight. Necropsies of coelomic organs were conducted on 10 axolotls (females = 5; males = 5) and ultrasound on 11 (males = 5; females = 6). Animals were kept in water and maintained conscious during ultrasound. The heart, caudal vena cava, liver, gallbladder, spleen, esophagus, stomach, colon, kidneys, ovaries, and fat bodies were identified in all study subjects, although testicles were identified in only 6/7 subjects. The pancreas and adrenal glands could not be identified in any animals, either during necropsy or ultrasonography. Coelomic and pericardial effusion was present in all animals. Ultrasonographic measurements of the liver, spleen, myocardial thickness, and right and left kidney length were highly repeatable (correlation value [CV] < 5%) and the esophagus, spleen, caudal vena cava, fat bodies, gallbladder, colon thickness, right kidney height and width, and right testicle diameter were statistically repeatable (CV < 10%).

Case report: Intracoelomic neoplastic mass of undetermined origin in an Asia minor spur-thighed tortoise (Testudo graeca ibera).

This article describes the diagnostic, treatment and attempted characterization of a neoplasia of undetermined origin in a Asia minor spur-thighed tortoise. A 21-year-old male Asia minor spur-thighed tortoise (Testudo graeca ibera) was admitted for a 4-month history of diarrhea, and a 2-month history of anorexia and lethargy. Physical examination revealed a firm midcoelomic mass in the right prefemoral fossa. Blood biochemistry indicated hypocalcemia and mild elevation of aspartate aminotransferase. Supportive care was administered in the form of heating, baths, and calcium injections. Ultrasound examination of the coelomic cavity revealed a 6-cm diameter, highly vascularized mass with liver-like echogenicity. Neoplasia was suspected, and endoscopy was performed, revealing a brown circumscribed mass with smooth edges. Surgical removal of the mass was evaluated by CT scan and achieved via a plastrotomy; however, the patient died 1 day post-surgery. The mass was located on the dorsal right side of the coelomic cavity in the anatomic location of the right testicle. Histopathology revealed neoplastic cells organized in packets supported by fibrous septa. Neoplastic cells showed moderate and inconsistent positive immunohistochemical labeling for S100 and NSE, and negative immunohistochemical labeling for pan-cytokeratin, vimentin, CD3, CD79a, chromogranin A, and synaptophysin. The prominent histological and anatomical characteristics of the mass indicated a possible testicular or neuroendocrine (e.g., adrenal gland) origin. Due to inconclusive immunohistochemical profiles and poorly differentiated neoplastic cells, only a final diagnosis of intracoelomic malignant tumor of undetermined origin could be established. This case underscores the difficulties encountered in achieving definitive diagnoses of neoplastic diseases in reptile medicine.

Pancuronium Bromide for Chemical Immobilization of Adult Nile Crocodiles (Crocodylus niloticus): A Field Study.

(1) Background: Pancuronium bromide is a neuromuscular blocker used for immobilizing crocodiles that can be reversed with neostigmine. A recommended drug dose has only been established for saltwater crocodiles (Crocodylus porosus), mostly based on trials in juveniles and subadults. After trialing a dose recommendation in a small cohort of nine Nile crocodiles (Crocodylus niloticus), we developed and applied a new dose recommendation for large adult Nile crocodiles. (2) Methods: we trialed and adapted a pancuronium bromide (Pavulon 4 mg/2 mL) dose in Nile crocodiles originally established for saltwater crocodiles and applied the new dose for the immobilization of 32 Nile crocodiles destined for transport. Reversal was achieved with neostigmine (Stigmine 0.5 mg/mL). (3) Results: Nine crocodiles were included in the trial phase; the induction time was highly variable (average: 70 min; range: 20-143 min), and the recovery time was prolonged (average: 22 h; range: 50 min-5 days), especially in large animals after reversal with neostigmine. Based on these results, we established a dose-independent recommendation (3 mg pancuronium bromide and 2.5 mg neostigmine) for animals weighing ≥ 270 kg (TL ≥ ~3.8 m). When applied to 32 adult male crocodiles (BW range: 270-460 kg; TL range: 3.76-4.48 m), the shortest induction time was ~20 min and the longest ~45 min. (4) Conclusions: Pancuronium bromide and its antidote, neostigmine, are effective for the immobilization and reversal of adult male Nile crocodiles (TL ≥ 3.8 m or BW ≥ 270 kg) when given in a weight-independent fashion.

Major Emerging Fungal Diseases of Reptiles and Amphibians.

Emerging infectious diseases (EIDs) are caused by pathogens that have undergone recent changes in terms of geographic spread, increasing incidence, or expanding host range. In this narrative review, we describe three important fungal EIDs with keratin trophism that are relevant to reptile and amphibian conservation and veterinary practice. Nannizziopsis spp. have been mainly described in saurians; infection results in thickened, discolored skin crusting, with eventual progression to deep tissues. Previously only reported in captive populations, it was first described in wild animals in Australia in 2020. Ophidiomyces ophidiicola (formely O. ophiodiicola) is only known to infect snakes; clinical signs include ulcerating lesions in the cranial, ventral, and pericloacal regions. It has been associated with mortality events in wild populations in North America. Batrachochytrium spp. cause ulceration, hyperkeratosis, and erythema in amphibians. They are a major cause of catastrophic amphibian declines worldwide. In general, infection and clinical course are determined by host-related characteristics (e.g., nutritional, metabolic, and immune status), pathogens (e.g., virulence and environmental survival), and environment (e.g., temperature, hygrometry, and water quality). The animal trade is thought to be an important cause of worldwide spread, with global modifications in temperature, hygrometry, and water quality further affecting fungal pathogenicity and host immune response.

Characterization of the Halochromic Gloeocapsin Pigment, a Cyanobacterial Biosignature for Paleobiology and Astrobiology.

Ultraviolet (UV)-screening compounds represent a substantial asset for the survival of cyanobacteria in extreme environments exposed to high doses of UV radiations on modern and early Earth. Among these molecules, the halochromic pigment gloeocapsin remains poorly characterized and studied. In this study, we identified a gloeocapsin-producing cultivable cyanobacteria: the strain Phormidesmis nigrescens ULC007. We succeeded to extract, to partially purify, and to compare the dark blue pigment from both the ULC007 culture and an environmental Gloeocapsa alpina dominated sample. FT-IR and Raman spectra of G. alpina and P. nigrescens ULC007 pigment extracts strongly suggested a common backbone structure. The high-pressure liquid chromatography-UV-MS/MS analysis of the ULC007 pigment extract allowed to narrow down the molecular formula of gloeocapsin to potentially five candidates within three classes of halochromic molecules: anthraquinone derivatives, coumarin derivatives, and flavonoids. With the discovery of gloeocapsin in P. nigrescens, the production of this pigment is now established for three lineages of cyanobacteria (including G. alpina, P. nigrescens, and Solentia paulocellulare) that belong to three distinct orders (Chroococcales, Pleurocapsales, Synechoccocales), inhabiting very diverse environments. This suggests that gloeocapsin production was a trait of their common ancestor or was acquired by lateral gene transfer. This work represents an important step toward the elucidation of the structure of this enigmatic pigment and its biosynthesis, and it potentially provides a new biosignature for ancient cyanobacteria. It also gives a glimpse on the evolution of UV protection strategies, which are relevant for early phototrophic life on Earth and possibly beyond.

Intracellular bound chlorophyll residues identify 1 Gyr-old fossils as eukaryotic algae.

The acquisition of photosynthesis is a fundamental step in the evolution of eukaryotes. However, few phototrophic organisms are unambiguously recognized in the Precambrian record. The in situ detection of metabolic byproducts in individual microfossils is the key for the direct identification of their metabolisms. Here, we report a new integrative methodology using synchrotron-based X-ray fluorescence and absorption. We evidence bound nickel-geoporphyrins moieties in low-grade metamorphic rocks, preserved in situ within cells of a ~1 Gyr-old multicellular eukaryote, Arctacellularia tetragonala. We identify these moieties as chlorophyll derivatives, indicating that A. tetragonala was a phototrophic eukaryote, one of the first unambiguous algae. This new approach, applicable to overmature rocks, creates a strong new proxy to understand the evolution of phototrophy and diversification of early ecosystems.

A Public Health Research Agenda for Managing Infodemics: Methods and Results of the First WHO Infodemiology Conference.

BACKGROUND: An infodemic is an overflow of information of varying quality that surges across digital and physical environments during an acute public health event. It leads to confusion, risk-taking, and behaviors that can harm health and lead to erosion of trust in health authorities and public health responses. Owing to the global scale and high stakes of the health emergency, responding to the infodemic related to the pandemic is particularly urgent. Building on diverse research disciplines and expanding the discipline of infodemiology, more evidence-based interventions are needed to design infodemic management interventions and tools and implement them by health emergency responders. OBJECTIVE: The World Health Organization organized the first global infodemiology conference, entirely online, during June and July 2020, with a follow-up process from August to October 2020, to review current multidisciplinary evidence, interventions, and practices that can be applied to the COVID-19 infodemic response. This resulted in the creation of a public health research agenda for managing infodemics. METHODS: As part of the conference, a structured expert judgment synthesis method was used to formulate a public health research agenda. A total of 110 participants represented diverse scientific disciplines from over 35 countries and global public health implementing partners. The conference used a laddered discussion sprint methodology by rotating participant teams, and a managed follow-up process was used to assemble a research agenda based on the discussion and structured expert feedback. This resulted in a five-workstream frame of the research agenda for infodemic management and 166 suggested research questions. The participants then ranked the questions for feasibility and expected public health impact. The expert consensus was summarized in a public health research agenda that included a list of priority research questions. RESULTS: The public health research agenda for infodemic management has five workstreams: (1) measuring and continuously monitoring the impact of infodemics during health emergencies; (2) detecting signals and understanding the spread and risk of infodemics; (3) responding and deploying interventions that mitigate and protect against infodemics and their harmful effects; (4) evaluating infodemic interventions and strengthening the resilience of individuals and communities to infodemics; and (5) promoting the development, adaptation, and application of interventions and toolkits for infodemic management. Each workstream identifies research questions and highlights 49 high priority research questions. CONCLUSIONS: Public health authorities need to develop, validate, implement, and adapt tools and interventions for managing infodemics in acute public health events in ways that are appropriate for their countries and contexts. Infodemiology provides a scientific foundation to make this possible. This research agenda proposes a structured framework for targeted investment for the scientific community, policy makers, implementing organizations, and other stakeholders to consider.

In Situ Fe and S isotope analyses in pyrite from the 3.2 Ga Mendon Formation (Barberton Greenstone Belt, South Africa): Evidence for early microbial iron reduction.

On the basis of phylogenetic studies and laboratory cultures, it has been proposed that the ability of microbes to metabolize iron has emerged prior to the Archaea/Bacteria split. However, no unambiguous geochemical data supporting this claim have been put forward in rocks older than 2.7-2.5 giga years (Gyr). In the present work, we report in situ Fe and S isotope composition of pyrite from 3.28- to 3.26-Gyr-old cherts from the upper Mendon Formation, South Africa. We identified three populations of microscopic pyrites showing a wide range of Fe isotope compositions, which cluster around two δ56 Fe values of -1.8‰ and +1‰. These three pyrite groups can also be distinguished based on the pyrite crystallinity and the S isotope mass-independent signatures. One pyrite group displays poorly crystallized pyrite minerals with positive Δ33 S values > +3‰, while the other groups display more variable and closer to 0‰ Δ33 S values with recrystallized pyrite rims. It is worth to note that all the pyrite groups display positive Δ33 S values in the pyrite core and similar trace element compositions. We therefore suggest that two of the pyrite groups have experienced late fluid circulations that have led to partial recrystallization and dilution of S isotope mass-independent signature but not modification of the Fe isotope record. Considering the mineralogy and geochemistry of the pyrites and associated organic material, we conclude that this iron isotope systematic derives from microbial respiration of iron oxides during early diagenesis. Our data extend the geological record of dissimilatory iron reduction (DIR) back more than 560 million years (Myr) and confirm that micro-organisms closely related to the last common ancestor had the ability to reduce Fe(III).

Environmentally Friendly Surface Modification Treatment of Flax Fibers by Supercritical Carbon Dioxide.

The present work investigates the effects of an environmentally friendly treatment based on supercritical carbon dioxide (scCO2) on the interfacial adhesion of flax fibers with thermoset matrices. In particular, the influence of this green treatment on the mechanical (by single yarn tensile test), thermal (by TGA), and chemical (by FT-IR) properties of commercially available flax yarns was preliminary addressed. Results showed that scCO2 can significantly modify the biochemical composition of flax fibers, by selectively removing lignin and hemicellulose, without altering their thermal stability and, most importantly, their mechanical properties. Single yarn fragmentation test results highlighted an increased interfacial adhesion after scCO2 treatment, especially for the vinylester matrix, in terms of reduced debonding and critical fragment length values compared to the untreated yarns by 18.9% and 15.1%, respectively. The treatment was less effective for epoxy matrix, for which debonding and critical fragment length values were reduced to a lesser extent, by 3.4% and 3.7%, respectively.

Author Correction: Early fungi from the Proterozoic era in Arctic Canada.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Early fungi from the Proterozoic era in Arctic Canada.

Fungi are crucial components of modern ecosystems. They may have had an important role in the colonization of land by eukaryotes, and in the appearance and success of land plants and metazoans1-3. Nevertheless, fossils that can unambiguously be identified as fungi are absent from the fossil record until the middle of the Palaeozoic era4,5. Here we show, using morphological, ultrastructural and spectroscopic analyses, that multicellular organic-walled microfossils preserved in shale of the Grassy Bay Formation (Shaler Supergroup, Arctic Canada), which dates to approximately 1,010-890 million years ago, have a fungal affinity. These microfossils are more than half a billion years older than previously reported unambiguous occurrences of fungi, a date which is consistent with data from molecular clocks for the emergence of this clade6,7. In extending the fossil record of the fungi, this finding also pushes back the minimum date for the appearance of eukaryotic crown group Opisthokonta, which comprises metazoans, fungi and their protist relatives8,9.

Cyanobacteria evolution: Insight from the fossil record.

Cyanobacteria played an important role in the evolution of Early Earth and the biosphere. They are responsible for the oxygenation of the atmosphere and oceans since the Great Oxidation Event around 2.4 Ga, debatably earlier. They are also major primary producers in past and present oceans, and the ancestors of the chloroplast. Nevertheless, the identification of cyanobacteria in the early fossil record remains ambiguous because the morphological criteria commonly used are not always reliable for microfossil interpretation. Recently, new biosignatures specific to cyanobacteria were proposed. Here, we review the classic and new cyanobacterial biosignatures. We also assess the reliability of the previously described cyanobacteria fossil record and the challenges of molecular approaches on modern cyanobacteria. Finally, we suggest possible new calibration points for molecular clocks, and strategies to improve our understanding of the timing and pattern of the evolution of cyanobacteria and oxygenic photosynthesis.

The earliest evidence for modern-style plate tectonics recorded by HP-LT metamorphism in the Paleoproterozoic of the Democratic Republic of the Congo.

Knowing which geodynamic regimes characterised the early Earth is a fundamental question. This implies to determine when and how modern plate tectonics began. Today, the tectonic regime is dominated by mobile-lid tectonics including deep and cold subduction. However, in the early Earth (4.5 to 2 Ga) stagnant-lid tectonics may also have occurred. The study of high pressure-low temperature (HP-LT) metamorphic rocks is important, because these rocks are only produced in present-day subduction settings. Here, we characterize the oldest known HP-LT eclogite worldwide (2089 ± 13 Ma; 17-23 kbar/500-550 °C), discovered in the Democratic Republic of the Congo. We provide evidence that the mafic protolith of the eclogite formed at 2216 ± 26 Ma in a rift-type basin, and was then subducted to mantle depths (>55 km) before being exhumed during a complete Wilson cycle lasting ca. 130 Ma. Our results indicate the operation of modern mobile-lid plate tectonics at 2.2-2.1 Ga.

Crystal structure of the diglycidyl ether of eugenol.

The diep-oxy monomer, C13H16O4 {DGE-Eu; systematic name: 2-[3-meth-oxy-4-(oxiran-2-ylmeth-oxy)benz-yl]oxirane}, was synthesized from eugenol by a three-step reaction. It consists of a 1,2,4-tris-ubstituted benzene ring substituted by diglycidyl ether, a meth-oxy group and a methyl-oxirane group. The three-membered oxirane rings are inclined to the benzene ring by 61.0 (3) and 27.9 (3)°. The methyl-ene C atom of one of the two terminal epoxide rings is positionally disordered [refined occupancy ratio = 0.69 (1):0.31 (1)]. In the crystal, mol-ecules are linked by C-H⋯O hydrogen bonds, forming layers parallel to the ab plane. The layers are linked by C-H⋯π inter-actions, forming a three-dimensional network.