Biotic alteration of oceanic basalt glass

The subsurface microbial biosphere in the igneous oceanic crust has implications for global geochemical cycling, early life on Earth, and the search for life on Mars. Microscopic evidence of a subsurface microbial ecosystem includes biotic alteration textures associated with basaltic glass. The exact conditions in the basaltic layer that make this a viable ecosystem remain unknown. Geologic investigations rely on the principle that the present is the key to the past and therefore the conditions evident in rocks today can be used to elucidate conditions occurring over time. The application of this principle to basaltic rocks sampled from the modern ocean containing biotic alteration textures is the primary objective of this study. This study is a global investigation into the relationship between the morphology of biotic alteration and its abundance in the ocean crust and the environmental conditions associated with the host rocks. The Ocean Drilling Program and the Deep Sea Drilling program provided subseafloor basaltic glass samples used in this study. The unique morphologies of the biotic alteration textures present were identified using a classification system and the abundance of biotic alteration was estimated as a percent of the total alteration present in the samples. Nine distinctive textures were selected for correlation with five environmental parameters including sample age, sample depth in basalt, overlying sediment thickness, temperature, and secondary mineralogy. These parameters served as proxies for the environment associated with biotic alteration such as oxidizing conditions, fluid flow, pH, and temperature tolerances for microbial growth. Preliminary results indicated the abundance and the frequency of biotic alteration textures varied with the environmental conditions. Statistical analyses were conducted to assess the strength and direction of the variation between the biotic alteration and environmental parameters. I found that several biotic alteration textures and biotic alteration abundance had statistically significant correlations with sample age, sample depth into basalt, temperature, and some secondary minerals. The subseafloor biosphere is a complex environment influenced by many variables. This investigation into how the evidence of biotic alteration preserved in basaltic glass varies with the environmental conditions represents a step towards understanding the dynamics of the ecosystem in the ocean crust

Oldest Known Eucalyptus Macrofossils Are from South America

The evolutionary history of Eucalyptus and the eucalypts, the larger clade of seven genera including Eucalyptus that today have a natural distribution almost exclusively in Australasia, is poorly documented from the fossil record. Little physical evidence exists bearing on the ancient geographical distributions or morphologies of plants within the clade. Herein, we introduce fossil material of Eucalyptus from the early Eocene (ca. 51.9 Ma) Laguna del Hunco paleoflora of Chubut Province, Argentina; specimens include multiple leaves, infructescences, and dispersed capsules, several flower buds, and a single flower. Morphological similarities that relate the fossils to extant eucalypts include leaf shape, venation, and epidermal oil glands; infructescence structure; valvate capsulate fruits; and operculate flower buds. The presence of a staminophore scar on the fruits links them to Eucalyptus, and the presence of a transverse scar on the flower buds indicates a relationship to Eucalyptus subgenus Symphyomyrtus. Phylogenetic analyses of morphological data alone and combined with aligned sequence data from a prior study including 16 extant eucalypts, one outgroup, and a terminal representing the fossils indicate that the fossils are nested within Eucalyptus. These are the only illustrated Eucalyptus fossils that are definitively Eocene in age, and the only conclusively identified extant or fossil eucalypts naturally occurring outside of Australasia and adjacent Mindanao. Thus, these fossils indicate that the evolution of the eucalypt group is not constrained to a single region. Moreover, they strengthen the taxonomic connections between the Laguna del Hunco paleoflora and extant subtropical and tropical Australasia, one of the three major ecologic-geographic elements of the Laguna del Hunco paleoflora. The age and affinities of the fossils also indicate that Eucalyptus subgenus Symphyomyrtus is older than previously supposed. Paleoecological data indicate that the Patagonian Eucalyptus dominated volcanically disturbed areas adjacent to standing rainforest surrounding an Eocene caldera lake

Macrophage scavenger receptor 1 mediates lipid-induced inflammation in non-alcoholic fatty liver disease

Background & Aims: Obesity-associated inflammation is a key player in the pathogenesis of non-alcoholic fatty liver disease (NAFLD). However, the role of macrophage scavenger receptor 1 (MSR1, CD204) remains incompletely understood. Methods: A total of 170 NAFLD liver biopsies were processed for transcriptomic analysis and correlated with clinicopathological features. Msr1-/- and wild-type mice were subjected to a 16-week high-fat and high-cholesterol diet. Mice and ex vivo human liver slices were treated with a monoclonal antibody against MSR1. Genetic susceptibility was assessed using genome-wide association study data from 1,483 patients with NAFLD and 430,101 participants of the UK Biobank. Results: MSR1 expression was associated with the occurrence of hepatic lipid-laden foamy macrophages and correlated with the degree of steatosis and steatohepatitis in patients with NAFLD. Mice lacking Msr1 were protected against diet-induced metabolic disorder, showing fewer hepatic foamy macrophages, less hepatic inflammation, improved dyslipidaemia and glucose tolerance, and altered hepatic lipid metabolism. Upon induction by saturated fatty acids, MSR1 induced a pro-inflammatory response via the JNK signalling pathway. In vitro blockade of the receptor prevented the accumulation of lipids in primary macrophages which inhibited the switch towards a pro-inflammatory phenotype and the release of cytokines such as TNF-ɑ. Targeting MSR1 using monoclonal antibody therapy in an obesity-associated NAFLD mouse model and human liver slices resulted in the prevention of foamy macrophage formation and inflammation. Moreover, we identified that rs41505344, a polymorphism in the upstream transcriptional region of MSR1, was associated with altered serum triglycerides and aspartate aminotransferase levels in a cohort of over 400,000 patients. Conclusions: Taken together, our data suggest that MSR1 plays a critical role in lipid-induced inflammation and could thus be a potential therapeutic target for the treatment of NAFLD. Lay summary: Non-alcoholic fatty liver disease (NAFLD) is a chronic disease primarily caused by excessive consumption of fat and sugar combined with a lack of exercise or a sedentary lifestyle. Herein, we show that the macrophage scavenger receptor MSR1, an innate immune receptor, mediates lipid uptake and accumulation in Kupffer cells, resulting in liver inflammation and thereby promoting the progression of NAFLD in humans and mice

First evidence for Wollemi Pine-type pollen (Dilwynites: Araucariaceae) in South America

We report the first fossil pollen from South America of the lineage that includes the recently discovered, extremely rare Australian Wollemi Pine, Wollemia nobilis (Araucariaceae). The grains are from the late Paleocene to early middle Eocene Ligorio Márquez Formation of Santa Cruz, Patagonia, Argentina, and are assigned to Dilwynites, the fossil pollen type that closely resembles the pollen of modern Wollemia and some species of its Australasian sister genus, Agathis. Dilwynites was formerly known only from Australia, New Zealand, and East Antarctica. The Patagonian Dilwynites occurs with several taxa of Podocarpaceae and a diverse range of cryptogams and angiosperms, but not Nothofagus. The fossils greatly extend the known geographic range of Dilwynites and provide important new evidence for the Antarctic region as an early Paleogene portal for biotic interchange between Australasia and South America.Mike Macphail, Raymond J. Carpenter, Ari Iglesias, Peter Wil

Health technology assessment

Health technology assessment (HTA) is a process by which the worth of a new health care technology is described, principally by gathering, collating, and synthesizing evidence. This synthesis is then used to determine whether the technology should be adopted. The HTA process is linked to national and international regulatory systems that approve health technologies for routine clinical use

Elective neck dissection for salvage total laryngectomy: A systematic review, meta-analysis and "decision-to-treat" approach.

IntroductionThe authors provide an updated, systematic and comprehensive summary of the literature concerning management of the N0 neck in patients for whom primary irradiation for squamous cell carcinoma of the larynx has been unsuccessful and salvage surgery in the form of total laryngectomy (TL) advocated.MethodsBibliographic databases MEDLINE, Cochrane, PubMed and Embase were searched from inception to April 2019, with no language restrictions. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. Risk of bias was defined using the Joanna Briggs Institute guidelines. Outcome measures were defined as the impact of END on locoregional control, complication rate, disease-specific and overall survival (DSS and OS).ResultsThe primary search identified 19 eligible articles, comprising 1353 patients, (1552 ENDs). The overall risk of occult metastases was 14% (9% of ENDs). The relative risk (RR) of developing complications was 1.29 when END was performed, compared to observation of the neck (CI 0.86-1.92). Contrariwise, patients in whom the neck was managed with neck dissection had a decreased risk of developing regional recurrence (RR 0.62, CI 0.35-1.08). There was no statistically significant variation between DSS and OS between END and neck observation groups, respectively.SummaryEND during salvage TL may reduce the rate of regional recurrence, but not at the expense of improving DSS or OS. Rates of occult metastases, regional recurrence and “cure” through salvage neck dissection are not equivalent. Significant bias in all collated manuscripts should encourage the reader to interpret conclusions with caution. Patients should be fully involved in the decision-making process and their performance status and co-morbidities taken carefully into account when deciding to increase the extent of surgery, which we believe should remain limited to TL in the majority of cases