83 research outputs found

    The genetic basis and evolution of red blood cell sickling in deer

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    Crescent-shaped red blood cells, the hallmark of sickle-cell disease, present a striking departure from the biconcave disc shape normally found in mammals. Characterized by increased mechanical fragility, sickled cells promote haemolytic anaemia and vaso-occlusions and contribute directly to disease in humans. Remarkably, a similar sickle-shaped morphology has been observed in erythrocytes from several deer species, without obvious pathological consequences. The genetic basis of erythrocyte sickling in deer, however, remains unknown. Here, we determine the sequences of human β-globin orthologues in 15 deer species and use protein structural modelling to identify a sickling mechanism distinct from the human disease, coordinated by a derived valine (E22V) that is unique to sickling deer. Evidence for long-term maintenance of a trans-species sickling/non-sickling polymorphism suggests that sickling in deer is adaptive. Our results have implications for understanding the ecological regimes and molecular architectures that have promoted convergent evolution of sickling erythrocytes across vertebrates

    Fish Intelligence, Sentience and Ethics

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    Fish are one of the most highly utilised vertebrate taxa by humans; they are harvested from wild stocks as part of global fishing industries, grown under intensive aquaculture conditions, are the most common pet and are widely used for scientific research. But fish are seldom afforded the same level of compassion or welfare as warm-blooded vertebrates. Part of the problem is the large gap between people’s perception of fish intelligence and the scientific reality. This is an important issue because public perception guides government policy. The perception of an animal’s intelligence often drives our decision whether or not to include them in our moral circle. From a welfare perspective, most researchers would suggest that if an animal is sentient, then it can most likely suffer and should therefore be offered some form of formal protection. There has been a debate about fish welfare for decades which centres on the question of whether they are sentient or conscious. The implications for affording the same level of protection to fish as other vertebrates are great, not least because of fishing-related industries. Here, I review the current state of knowledge of fish cognition starting with their sensory perception and moving on to cognition. The review reveals that fish perception and cognitive abilities often match or exceed other vertebrates. A review of the evidence for pain perception strongly suggests that fish experience pain in a manner similar to the rest of the vertebrates. Although scientists cannot provide a definitive answer on the level of consciousness for any nonhuman vertebrate, the extensive evidence of fish behavioural and cognitive sophistication and pain perception suggests that best practice would be to lend fish the same level of protection as any other vertebrate

    Assessing transmissibility of SARS-CoV-2 lineage B.1.1.7 in England

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    The SARS-CoV-2 lineage B.1.1.7, designated variant of concern (VOC) 202012/01 by Public Health England1, was first identified in the UK in late summer to early autumn 20202. Whole-genome SARS-CoV-2 sequence data collected from community-based diagnostic testing for COVID-19 show an extremely rapid expansion of the B.1.1.7 lineage during autumn 2020, suggesting that it has a selective advantage. Here we show that changes in VOC frequency inferred from genetic data correspond closely to changes inferred by S gene target failures (SGTF) in community-based diagnostic PCR testing. Analysis of trends in SGTF and non-SGTF case numbers in local areas across England shows that B.1.1.7 has higher transmissibility than non-VOC lineages, even if it has a different latent period or generation time. The SGTF data indicate a transient shift in the age composition of reported cases, with cases of B.1.1.7 including a larger share of under 20-year-olds than non-VOC cases. We estimated time-varying reproduction numbers for B.1.1.7 and co-circulating lineages using SGTF and genomic data. The best-supported models did not indicate a substantial difference in VOC transmissibility among different age groups, but all analyses agreed that B.1.1.7 has a substantial transmission advantage over other lineages, with a 50% to 100% higher reproduction number

    Characterization of behavioral, signaling and cytokine alterations in a rat neurodevelopmental model for schizophrenia, and their reversal by the 5-HT₆ receptor antagonist SB-399885

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    Post-weaning social isolation of rats produces neuroanatomical, neurochemical and behavioral alterations resembling some core features of schizophrenia. This study examined the ability of the 5-HT₆ receptor antagonist SB-399885 to reverse isolation-induced cognitive deficits, then investigated alterations in hippocampal cell proliferation and hippocampal and frontal cortical expression of selected intracellular signaling molecules and cytokines. Male Lister-hooded rats (weaned on post-natal day 21-24 and housed individually or in groups of 3-4) received six i.p. injections of vehicle (1% Tween 80, 1 mL/kg) or SB-399885 (5 or 10 mg/kg) over a two week period starting 40 days post-weaning, on the days that locomotor activity, novel object discrimination (NOD), pre-pulse inhibition of acoustic startle and acquisition, retention and extinction of a conditioned freezing response (CFR) were assessed. Tissue was collected 24 h after the final injection for immunohistochemistry, reverse-phase protein microarray and western blotting. Isolation rearing impaired NOD and cue-mediated CFR, decreased cell proliferation within the dentate gyrus, and elevated hippocampal TNFα levels and Cdc42 expression. SB-399885 reversed the NOD deficit and partially normalized CFR and cell proliferation. These effects were accompanied by altered expression of several members of the c-Jun N-terminal Kinase (JNK) and p38 MAPK signaling pathways (including TAK1, MKK4 and STAT3). Although JNK and p38 themselves were unaltered at this time point hippocampal TAK1 expression and phosphorylation correlated with visual recognition memory in the NOD task. Continued use of this neurodevelopmental model could further elucidate the neurobiology of schizophrenia and aid assessment of novel therapies for drug-resistant cognitive symptoms

    Actinides isotopic analysis using a 1 MV AMS system

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    The VEGA 1 MV AMS system at ANSTO has been custom-designed to cover analysis of a wide range of long-lived radioisotopes, including routine radiocarbon analysis and multiple-isotope analysis of actinides. The system incorporates 1.0 m radius injection and analysing magnets with o -axis cups on high and low mass sides. Following the analysing magnet, rare isotope beams pass through a 1m radius spherical electrostatic analyser and a 120 1 m radius magnet. The detector station consists of a two-anode gas detector, with o -axis options to direct isotopes to either a Faraday cup or an electron multiplier ion counter. All three analysing magnets are fitted with electrostatic bouncer systems. At the LE end, the bouncer works in the usual way for all isotope combinations of interest, including 12C-13C-14C and actinides. The HE bouncers are used to transmit a range of masses of interest for actinides analysis, for example mass 239 to 244 Pu isotopes. For uranium analysis, the less rare isotopes can be directed to o axis cups or the ion counter. Software has been implemented to enable a high degree of exibility in analysing up to 8 isotopes at a time. In this paper we present details of the system and its performance and applications. © The Author

    Problems and solutions in laboratory testing for hemophilia.

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    A diagnosis of hemophilia A or hemophilia B begins with clinical assessment of the patient and is facilitated by laboratory testing. The influence of the latter on a diagnosis of hemophilia A or hemophilia B is clear-a diagnosis cannot be made without laboratory confirmation of a deficiency of factor FVIII (FVIII) or factor IX (FIX), respectively. Moreover, the degree of hemophilia severity is specifically characterized by laboratory test results. In turn, patient management, including choice and application of therapies, is influenced by the diagnosis, as well as by identification of respective disease severity. An incorrect diagnosis may lead to inappropriate management and unnecessary therapy, and thus to adverse outcomes. Moreover, identification of factor inhibitors in hemophilia will lead to additional and differential treatments, and incorrect identification of inhibitors or inhibitor levels may also lead to inappropriate management. Problems in hemophilia diagnosis or inhibitor detection can occur at any stage in the clinical diagnosis/laboratory interface, from the "pre-preanalytical" to "preanalytical" to "analytical" to "postanalytical" to "post-postanalytical." This report outlines the various problems in laboratory testing for hemophilia and provides various strategies or solutions to overcome these challenges. Although some outlined solutions are specific to the potential errors related to hemophilia, others are general in nature and can be applied to other areas of laboratory hemostasis. Key to improvement in this area is adoption of best practice by all involved, including clinicians, phlebotomists, and laboratories. Also key is the recognition that such errors may occur, and thus that clinicians should assess laboratory test results in the context of their patient's clinical history and follow-up any potential errors, thus avoid misdiagnoses, by requesting repeat testing on a fresh sample
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