623 research outputs found

    Charles W. Peach, palaeobotany and Scotland

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    The move south from Wick to the city of Edinburgh in 1865, some four years after retirement from the Customs service, provided Charles W. Peach with new opportunities for fossil-collecting and scientific networking. Here he renewed and maintained his interest in natural history and made significant palaeobotanical collections from the Carboniferous of the Midland Valley of Scotland. These are distinguished by some interesting characteristics of their documentation which the following generations of fossil collectors and researchers would have done well to emulate. Many of his fossil plant specimens have not only the locality detail,but also the date, month and year of collection neatly handwritten on attached paper labels; as a result, we can follow Peach's collecting activities over a period of some 18 years or so. Comments and even illustrative sketches on the labels of some fossils give us first-hand insight into Peach's observations. Study of these collections now held in National Museums Scotland reveals a pattern of collecting heavily biased towards those localities readily accessible from the newly expanding railways which provided a relatively inexpensive and convenient means of exploring the geology of the neighbourhood of Edinburgh. Charles W. Peach had a very 'hands-on' practical approach to scientific investigation which led him to construct novel glass plates with mounted Sphenopteris cuticle, removed intact from Lower Carboniferous shales and limestones originating in West Lothian. These resemble the herbarium sheets with which he was familiar from his parallel and highly significant work on extant flora including nearshore marine algae. He also prepared hand ground glass microscope slides,particularly of permineralised plant material from Pettycur in Fife, using whatever materials he had to hand at the time. Peach's collection raises questions about the evolution of accepted standards of documentation in private collections, in parallel with the evolution of collecting practices by the new professionals such as the workers of the Geological Survey. Its relatively rapid deposition in museums,compared to many private collections, may also have contributed to its apparently high rate of usage by contemporary workers

    A harvestman (Arachnida: Opiliones) from the Early Devonian Rhynie cherts, Aberdeenshire, Scotland

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    A harvestman (Arachnida: Opiliones) is described from the Early Devonian (Pragian) Rhynie cherts, Aberdeenshire, Scotland. Eophalangium sheari gen. et sp. nov. is the oldest known harvestman. The material includes both males and a female preserving, respectively, a cuticle-lined penis and ovipositor within the opisthosoma. Both these structures are of essentially modern appearance. The Rhynie fossils also show tracheae which are, again, very similar to those of living harvestmen. This is the oldest unequivocal record of arachnid tracheal respiration and indicates that E. sheari was terrestrial. An annulate, setose ovipositor in the female suggests that it can be excluded from the clades Dyspnoi and Laniatores, in which the ovipositor lacks such annulations. However, the penis shows evidence of two muscles, a feature of uncertain polarity seen in modern Troguloidea (Dyspnoi). The presence of median eyes and long legs excludes Cyphophthalmi, and thus, E. sheari is tentatively referred to the suborder Eupnoi. Therefore, this remarkable material is implicitly a crown-group harvestman and is one of the oldest known crown-group chelicerates. It also suggests an extraordinary degree of morphological stasis within the eupnoid line, with the Devonian forms differing little in gross morphology – and perhaps in reproductive behaviour – from their modern counterparts.Peer Reviewe

    The incidence of congenital syphilis in the United Kingdom: February 2010 to January 2015

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    OBJECTIVE: To estimate the incidence of congenital syphilis in the UK. DESIGN: Prospective study. SETTING AND POPULATION: United Kingdom. METHODS: Children born between February 2010 and January 2015 with a suspected diagnosis of congenital syphilis were reported through an active surveillance system. MAIN OUTCOME MEASURES: Number of congenital syphilis cases and incidence. RESULTS: For all years, reported incidence was below the WHO threshold for elimination (<0.5/1000 live births). Seventeen cases (12 male, five female) were identified. About 50% of infants (8/17) were born preterm (<37 weeks' gestation): median birthweight 2000 g (865-3170 g). Clinical presentation varied from asymptomatic to acute disease, including severe anaemia, hepatosplenomegaly, rhinitis, thrombocytopaenia, skeletal damage, and neurosyphilis. One infant was deaf and blind. Median maternal age was 20 years (17-31) at delivery. Where maternal stage of infection was recorded, 6/10 had primary, 3/10 secondary and 1/10 early latent syphilis. Most mothers were white (13/16). Country of birth was recorded for 12 mothers: UK (n = 6), Eastern Europe (n = 3), Middle East (n = 1), and South East Asia (n = 2). The social circumstances of mothers varied and included drug use and sex work. Some experienced difficulty accessing health care. CONCLUSION: The incidence of congenital syphilis is controlled and monitored by healthcare services and related surveillance systems, and is now below the WHO elimination threshold. However, reducing the public health impact of this preventable disease in the UK is highly dependent on the successful implementation of WHO elimination standards across Europe. TWEETABLE ABSTRACT: Congenital syphilis incidence in the UK is at a very low level and well below the WHO elimination threshold

    Respiratory muscle strength as a predictive biomarker for survival in amyotrophic lateral sclerosis

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    Rationale: Biomarkers for survival in amyotrophic lateral sclerosis (ALS) would facilitate the development of novel drugs. Although respiratory muscle weakness is a known predictor of poor prognosis, a comprehensive comparison of different tests is lacking. Objectives: To compare the predictive power of invasive and noninvasive respiratory muscle strength assessments for survival or ventilator-free survival, up to 3 years. Methods: From a previously published report respiratory muscle strength measurements were available for 78 patients with ALS. Time to death and/or ventilation were ascertained. Receiver operating characteristic analysis was used to determine the cutoff point of each parameter. Measurements and Main Results: Each respiratory muscle strength assessment individually achieved statistical significance for prediction of survival or ventilator-free survival. In multivariate analysis sniff trans-diaphragmatic and esophageal pressure, twitch trans-diaphragmatic pressure (Tw Pdi), age, and maximal static expiratory mouth pressure were significant predictors of ventilation-free survival and Tw Pdi and maximal static expiratory mouth pressure for absolute survival. Although all measures had good specificity, there were differing sensitivities. All cutoff points for the VC were greater than 80% of normal, except for prediction of 3-month outcomes. Sequential data showed a linear decline for direct measures of respiratory muscle strength, whereas VC showed little to no decline until 12 months before death/ventilation. Conclusions: The most powerful biomarker for mortality stratification was Tw Pdi, but the predictive power of sniff nasal inspiratory pressure was also excellent. A VC within normal range suggested a good prognosis at 3 months but was of little other value

    Cyclic-AMP regulates postnatal development of neural and behavioral responses to NaCl in rats

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    During postnatal development rats demonstrate an age-dependent increase in NaCl chorda tympani (CT) responses and the number of functional apical amiloride-sensitive epithelial Na+channels (ENaCs) in salt sensing fungiform (FF) taste receptor cells (TRCs). Currently, the intracellular signals that regulate the postnatal development of salt taste have not been identified. We investigated the effect of cAMP, a downstream signal for arginine vasopressin (AVP) action, on the postnatal development of NaCl responses in 19–23 day old rats. ENaC-dependent NaCl CT responses were monitored after lingual application of 8-chlorophenylthio-cAMP (8-CPT-cAMP) under open-circuit conditions and under ±60 mV lingual voltage clamp. Behavioral responses were tested using 2 bottle/24h NaCl preference tests. The effect of [deamino-Cys1, D-Arg8]-vasopressin (dDAVP, a specific V2R agonist) was investigated on ENaC subunit trafficking in rat FF TRCs and on cAMP generation in cultured adult human FF taste cells (HBO cells). Our results show that in 19–23 day old rats, the ENaC-dependent maximum NaCl CT response was a saturating sigmoidal function of 8-CPT-cAMP concentration. 8-CPT-cAMP increased the voltage-sensitivity of the NaCl CT response and the apical Na+ response conductance. Intravenous injections of dDAVP increased ENaC expression and γ-ENaC trafficking from cytosolic compartment to the apical compartment in rat FF TRCs. In HBO cells dDAVP increased intracellular cAMP and cAMP increased trafficking of γ- and δ-ENaC from cytosolic compartment to the apical compartment 10 min post-cAMP treatment. Control 19–23 day old rats were indifferent to NaCl, but showed clear preference for appetitive NaCl concentrations after 8-CPT-cAMP treatment. Relative to adult rats, 14 day old rats demonstrated significantly less V2R antibody binding in circumvallate TRCs. We conclude that an age-dependent increase in V2R expression produces an AVP-induced incremental increase in cAMP that modulates the postnatal increase in TRC ENaC and the neural and behavioral responses to NaCl

    Comparing plasma and faecal measures of steroid hormones in Adelie penguins Pygoscelis adeliae

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    Physiological measurements of both stress and sex hormones are often used to estimate the consequences of natural or human-induced change in ecological studies of various animals. Different methods of hormone measurement exist, potentially explaining variation in results across studies; methods should be cross-validated to ensure that they correlate. We directly compared faecal and plasma hormone measurements for the first time in a wild free-living species, the Adelie penguin (Pygoscelis adeliae). Blood and faecal samples were simultaneously collected from individual penguins for comparison and assayed for testosterone and corticosterone (or their metabolites). Sex differences and variability within each measure, and correlation of values across measures were compared. For both hormones, plasma samples showed greater variation than faecal samples. Males had higher mean corticosterone concentrations than females, but the difference was only statistically significant in faecal samples. Plasma testosterone, but not faecal testosterone, was significantly higher in males than females. Correlation between sample types was poor overall, and weaker in females than in males, perhaps because measures from plasma represent hormones that are both free and bound to globulins, whereas measures from faeces represent only the free portion. Faecal samples also represent a cumulative measure of hormones over time, as opposed to a plasma ‘snapshot’ concentration. Our data indicate that faecal sampling appears more suitable for assessing baseline hormone concentrations, whilst plasma sampling may best define immediate responses to environmental events. Consequently, future studies should ensure that they select the most appropriate matrix and method of hormone measurement to answer their research questions
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