Septuagenarians with non‐small cell lung carcinoma can successfully undergo curative lung resection with a low incidence of post‐operative complications. A video‐assisted thoracoscopic surgery approach to surgical resection results in similar post‐operative outcomes to open thoracotomy; however, the significantly shorter mean hospital length of stay may be clinically relevant in this elderly population. Abstract Background Spread of technology and increased surveillance have led to more...
Wed Apr 29, 2020 15:40
A retrospective cohort study that has aimed to externally validate the American College of Surgeons National Surgical Quality Improvement Program surgical risk calculator in a high‐risk, Australian, emergency general surgery cohort was conducted. It was found that the calculator was accurate in being able to predict mortality in this group. This has implications on how we as surgeons can assess a patient's risk, how we approach the informed consent process and how we can optimize preoperative management...
Wed Apr 29, 2020 15:38
Investigating the different aetiologies associated with portal venous gas and their respective outcomes. Abstract Background Historically finding of portal venous gas (PVG) has been considered as an ominous sign and an indication for emergency surgery and reportedly has a high mortality rate. However, with the recent increasing use of imaging studies, cases of PVG associated with benign and non‐life‐threatening causes are increasing. The purpose of our study was to investigate the different...
Wed Apr 29, 2020 15:34
All patients in Victoria with pancreas cancer diagnosed between 2011 and 2015 were included in this population study. Of most note, 23% of patients treated with intended curative intent never received systemic therapy. Only 1.5% were treated with neoadjuvant therapy and 51% with metastatic disease never received any anti‐tumour treatment. Abstract Background The Victorian Pancreas Cancer summit 2017 analysed state‐wide data on management of Victorians with pancreas cancer between 2011 and...
Wed Apr 29, 2020 11:47
Nitrogen is an essential element to life and exerts a strong control on global biological productivity. The rise and spread of nitrogen-utilizing microbial metabolisms profoundly shaped the biosphere on the early Earth. Here we reconciled gene and species trees to identify birth and horizontal gene transfer events for key nitrogen-cycling genes, dated with a time-calibrated tree of life, in order to examine the timing of the proliferation of these metabolisms across the tree of life. Our results...
03:00
Genetic correlations between traits may cause correlated responses to selection. Previous models described the conditions under which genetic correlations are expected to be maintained. Selection, mutation and migration are all proposed to affect genetic correlations, regardless of whether the underlying genetic architecture consists of pleiotropic or tightly-linked loci affecting the traits. Here, we investigate the conditions under which pleiotropy and linkage have differential effects on the genetic...
03:00
Artificial selection is a promising approach to manipulate the function of microbial communities. Here, we report the outcome of two artificial selection experiments at the microbial community level. Both experiments used "propagule" strategies, in which a set of the best-performing communities are used as the inocula to form a new generation of communities. In both cases, the selected communities are compared to a control treatment where communities are randomly selected. The first experiment used...
03:00
In a side-by-side comparison of evolutionary dynamics between the 2019/2020 SARS-CoV-2 and the 2003 SARS-CoV, we were surprised to find that SARS-CoV-2 resembles SARS-CoV in the late phase of the 2003 epidemic after SARS-CoV had developed several advantageous adaptations for human transmission. Our observations suggest that by the time SARS-CoV-2 was first detected in late 2019, it was already pre-adapted to human transmission to an extent similar to late epidemic SARS-CoV. However, no precursors...
Sat May 02, 2020 03:00
Organisms rely on inducible and constitutive immune defences to combat infection. Constitutive immunity enables a rapid response to infection but may carry a cost for uninfected individuals, leading to the prediction that it will be favoured when infection rates are high. When we exposed populations of Drosophila melanogaster to intense parasitism by the parasitoid wasp Leptopilina boulardi, they evolved resistance by developing a more reactive cellular immune response. Using single-cell RNA sequencing,...
Sat May 02, 2020 03:00
SARS-CoV-2, the causative agent of the COVID-2019 pandemic is an RNA virus prone to mutations. Information on mutations within the circulating strains of the virus is pivotal to understand disease spread and dynamics. Here, we analyse the mutations associated with 2,954 globally reported high quality genomes of SARS-CoV-2 with special emphasis on genomes of viral strains from India. Molecular phylogenetic analysis suggests that SARS-CoV-2 strains circulating in India form five distinct phyletic clades...
Sat May 02, 2020 03:00
Genetic conflict is considered a key driver in the evolution of new reproductive and sex determining systems. In particular, reproductive strategies with non-Mendelian inheritance, where parents do not contribute equally to the genetic makeup of their offspring. One of the most extraordinary examples of non-Mendelian inheritance is paternal genome elimination (PGE), a form of haplodiploidy which has evolved repeatedly across arthropods. Under PGE, males are diploid but only transmit maternally-inherited...
Sat May 02, 2020 03:00
Hybridization and introgression are common processes among numerous plant species that present both challenges and opportunities for studies of species delimitation, phylogenetics, taxonomy, and adaptation. Rhus integrifolia and R. ovata are two ecologically important shrubs native to the southwestern USA and Mexico, and are known to hybridize frequently, but the morphological, genetic, and ecological implications of hybridization in these species are poorly studied on a broad geographic scale. Analyses...
Sat May 02, 2020 03:00
Gonadotropic hormones coordinate processes in diverse tissues regulating animal reproductive physiology and behavior. Juvenile hormone (JH) is the ancient and most common gonadotropin in insects, but not in advanced eusocial honey bees and ants. To probe the evolutionary basis of this change, we combined endocrine manipulations, transcriptomics, and behavioral analyses to study JH regulated processes in a bumble bee showing an intermediate level of sociliality. We found that in the fat body, more...
Sat May 02, 2020 03:00
MicroRNA target sites are often conserved during evolution and purifying selection to maintain such sites is expected. On the other hand, comparative analyses identified a paucity of microRNA target sites in co-expressed transcripts, and novel target sites can potentially be deleterious. We proposed that selection against novel target sites pervasive. The analysis of derived allele frequencies revealed that, when the derived allele is a target site, the proportion of non-target sites is higher than...
Sat May 02, 2020 03:00
Sexually antagonistic (SA) genetic variation -- in which genotypes favoured in one sex are disfavoured in the other -- is predicted to be common and has been documented in several animal and plant populations, yet we currently know little about its pervasiveness among species or its population genetic basis. Recent applications of genomics in studies of SA genetic variation have highlighted considerable methodological challenges to the identification and characterisation of SA genes, raising questions...
Fri May 01, 2020 03:00
Schistosomiasis persists in some Asian regions despite targeted end-game elimination measures. To determine the causes of this persistence, we performed reduced representation genome sequencing on Schistosoma japonicum miracidia collected across multiple years from transmission hotspots in Sichuan, China. We discovered strong geographic structure, suggesting that local rather than imported reservoirs are key sources of infection persistence. At the village level, parasites collected after praziquantel...
Fri May 01, 2020 03:00
Among vertebrates, placental mammals are particularly variable in the covariance between their cranial shapes and body size (allometry), with the notable exception of rodents. Australian murid rodents present an opportunity to assess the cause of this anomaly because they radiated on an ecologically diverse continent unique for lacking other terrestrial placentals. Here we used 3D geometric morphometrics to quantify species-level and evolutionary allometries in 38 species (317 crania) from all Australian...
Fri May 01, 2020 03:00
Killer meiotic drivers are genetic parasites that destroy 'sibling' gametes lacking the driver allele. The fitness costs of drive can lead to selection of unlinked suppressors. This suppression could involve evolutionary tradeoffs that compromise gametogenesis and contribute to infertility. Schizosaccharomyces pombe, an organism containing numerous gamete-killing wtf drivers, offers a tractable system to test this hypothesis. Here, we demonstrate that in scenarios analogous to outcrossing, wtf drivers...
Fri May 01, 2020 03:00
Changes in complex phenotypes, such as pathogenicity levels, trophic lifestyle, and habitat shifts are brought on by multiple genomic changes: sub- and neo-functionalization, loss of function, and levels of gene expression. Thus, detecting the signature of selection in coding sequences and associating it with shifts in phenotypic state can unveil the genes underlying complex traits. Phylogenetic branch-site codon models are routinely applied to detect changes in selective patterns along specific...
Fri May 01, 2020 03:00
Evolutionary theory predicts that vertically transmitted symbionts are selected for low virulence, as their fitness is directly correlated to that of their host. In contrast with this prediction, the Wolbachia strain wMelPop drastically reduces its Drosophila melanogaster host lifespan at high rearing temperatures. It is generally assumed that this feature is maintained because the D. melanogaster-wMelPop symbiosis is usually not exposed to environmental conditions in which the symbiont is virulent....
Fri May 01, 2020 03:00
Experimental and theoretical studies have highlighted the impact of gene flow on the probability of evolutionary rescue in structured habitats. Mathematical modelling and simulations of evolutionary rescue in spatially or otherwise structured populations showed that intermediate migration rates can often maximize the probability of rescue in gradually or abruptly deteriorating habitats. These theoretical results corroborate the positive effect of gene flow on evolutionary rescue that has been identified...
Fri May 01, 2020 03:00
The evolutionary transition to multicellularity has occurred on numerous occasions, but transitions to complex life forms are rare. While the reasons are unclear, relevant factors include the intensity of within- versus between-group selection that are likely to have shaped the course of life cycle evolution. A highly structured environment eliminates the possibility of mixing between evolving lineages, thus ensuring strong competition between groups. Less structure intensifies competition within...
Thu Apr 30, 2020 03:00
We have developed an analysis pipeline to facilitate real-time mutation tracking in SARS-CoV-2, focusing initially on the Spike (S) protein because it mediates infection of human cells and is the target of most vaccine strategies and antibody-based therapeutics. To date we have identified fourteen mutations in Spike that are accumulating. Mutations are considered in a broader phylogenetic context, geographically, and over time, to provide an early warning system to reveal mutations that may confer...
Thu Apr 30, 2020 03:00
Resident microbes (microbiota) can shape host organismal function and adaptation in the face of environmental change. Invasion of new habitats exposes hosts to novel selection pressures, but the impacts on microbiota and their relationship with hosts after this transition (e.g., how rapidly symbioses are formed, whether microbes influence invasion success) are unclear. We used high-throughput 16S rRNA sequencing of New Zealand (native) and European (invasive) populations of the freshwater snail Potamopyrgus...
Thu Apr 30, 2020 03:00
Communication based on small signalling molecules is widespread among bacteria. Recently, such communication was also described in bacteriophages. Upon infection of a host cell, temperate phages of the Bacillus subtilis-infecting SPbeta group induce the secretion of a phage-encoded signalling peptide, which is used to inform the lysis-lysogeny decision in subsequent infections: the phages produce new virions and lyse their host cell when the signal concentration is low, but favour a latent infection...
Thu Apr 30, 2020 03:00
Polyploidy is pervasive in angiosperm evolution and plays important roles in adaptation and speciation. However, polyploid groups are understudied due to complex sequence homology, challenging genome assembly, and taxonomic complexity. Here we study adaptive divergence in taxonomically complex eyebrights (Euphrasia), where recent divergence, phenotypic plasticity and hybridisation blur species boundaries. We focus on three closely-related tetraploid species with contrasting ecological preferences,...
Thu Apr 30, 2020 03:00
Integrins are transmembrane receptor proteins that activate signal transduction pathways upon extracellular matrix binding. The Integrin Mediated Adhesion Complex (IMAC), mediates various cell physiological process. The IMAC was thought to be an animal specific machinery until over the last decade these complexes were discovered in Obazoa, the group containing animals, fungi, and several microbial eukaryote lineages. Amoebozoa is the eukaryotic supergroup sister to Obazoa. Even though Amoebozoa represents...
Thu Apr 30, 2020 03:00
Heliamphora is a genus of carnivorous pitcher plants endemic to the Guiana Highlands with fragmented distributions. We presented a well resolved, time-calibrated, and nearly comprehensive Heliamphora phylogeny estimated using Bayesian inference and maximum likelihood based on nuclear genes (26S, ITS, and PHYC) and secondary calibration. We used stochastic mapping to infer ancestral states of morphological characters and ecological traits. Our ancestral state estimations revealed that the pitcher...
Thu Apr 30, 2020 03:00
Despite reproducing without sexual recombination, the root-knot nematode Meloidogyne incognita is adaptive and versatile. Indeed, this species displays a global distribution, is able to parasitize a large range of plants and can overcome plant resistance in a few generations. The mechanisms underlying this adaptability without sex remain poorly known and only low variation at the single nucleotide polymorphism level have been observed so far across different geographical isolates with distinct ranges...
Thu Apr 30, 2020 03:00
O_LIPlant volatile emissions can recruit predators of herbivores for indirect defence and attract pollinators to aid in pollination. Although volatiles involved in defence and pollinator attraction are primarily emitted from leaves and flowers, respectively, they will co-evolve if their underlying genetic basis is intrinsically linked, either due to pleiotropy or genetic linkage. However, direct evidence of co-evolving defence and floral traits is scarce. C_LIO_LIWe characterized intra-specific...
Thu Apr 30, 2020 03:00
Ammonia-oxidising archaea of the phylum Thaumarchaeota are keystone species in global nitrogen cycling. However, only three of the six known families of the terrestrially ubiquitous order Nitrososphaerales possess representative genomes. Here we provide genomes for the three remaining families and examine the impact of gene duplication, loss and transfer events across the entire phylum. Much of the genomic divergence in this phylum is driven by gene duplication and loss, but we also detected early...
Thu Apr 30, 2020 03:00
To be able to deal with uncertainty is of primary importance to all organisms. When cues provide information about the state of the environment, organisms can use them to respond flexibly. Thus information can provide fitness advantages. Without environmental cues, an organism can reduce the risks of environmental uncertainty by hedging its bets across different scenarios. Risk mitigation is then possible by adopting a life-history of bet-hedging, either randomly switching between phenotypes (diversifying...
Thu Apr 30, 2020 03:00
Population genomic analysis of hybrid zones is instrumental to our understanding of the evolution of reproductive isolation. Many temperate hybrid zones are formed by the secondary contact between two parental populations that had undergone post-glacial range expansion. Here we show that explicitly accounting for historical parental isolation followed by range expansion prior to secondary contact is fundamental for explaining genetic and fitness patterns in these hybrid zones. Specifically, ancestral...
Thu Apr 30, 2020 03:00
As a heritable sequence-specific adaptive immune system, CRISPR-Cas is a powerful force shaping strain diversity in host-virus systems. While the diversity of CRISPR alleles has been explored, the associated structure and dynamics of host-virus interactions have not. We explore the role of CRISPR in mediating the interplay between host-virus interaction structure and eco-evolutionary dynamics in a computational model and compare results with three empirical datasets from natural systems. We show...
Thu Apr 30, 2020 03:00
Many non-sproulating bacterial species can survive for years within exhausted growth media in a state termed long-term stationary phase (LTSP). We have been carrying out evolutionary experiments aimed at elucidating the dynamics of genetic adaptation under LTSP. We showed that Escherichia coli adapts to prolonged resource exhaustion through the highly convergent acquisition of mutations. In the most striking example of such convergent adaptation, we observed that across all independently evolving...
Thu Apr 30, 2020 03:00
The zero-force evolutionary law (ZFEL) of McShea et al. states that independently evolving entities, with no forces or constraints acting on them, will tend to accumulate differences and therefore diverge from each other. McShea et al. quantified the law by assuming normality on an additive arithmetic scale and reflecting negative differences as absolute values, systematically augmenting perceived divergence. The appropriate analytical framework is not additive but proportional, where logarithmic...
Thu Apr 30, 2020 03:00
Insect Hox3/zen genes represent an evolutionary hotspot for changes in function and copy number. Single orthologues are required either for early specification or late morphogenesis of the extraembryonic tissues, which protect the embryo. The tandemly duplicated zen paralogues of the beetle Tribolium castaneum present a unique opportunity to investigate both functions in a single species. We dissect the paralogues' expression dynamics (transcript and protein) and transcriptional targets (RNA-seq...
Wed Apr 29, 2020 03:00
Feasibility, safety, and economic consequences of using low flow anesthesia according to body weight
Abstract Background Low flow anesthesia (LFA) provides a saving up to 75% and improves the dynamics of inhaled anesthesia gas, increases mucociliary clearance, maintains body temperature, and reduces water loss. LFA has been recommended for anesthesiologists in recent years to avoid high fresh gas flow (FGF). However, LFA use is limited due to associated risks. The main purpose of this study was to investigate whether LFA according...
03:00
Abstract Purpose Neurologic complications are seen often after the surgery of the thoracic aorta that uses selective antegrade cerebral perfusion. The objective of this study was to evaluate the impact of atherosclerotic risk factors on neurologic complications in patients who underwent surgery to the thoracic aorta using SCP. Methods Data were collected...
Sat May 02, 2020 03:00
Δεν υπάρχουν σχόλια:
Δημοσίευση σχολίου