67 research outputs found
Karyology of the redfin minnows, genus Pseudobarbus Smith, 1841 (Teleostei: Cyprinidae): one of the evolutionarily tetraploid lineages of South African barbines
The karyotypes of six species of Pseudobarbus Smith, 1841, namely P. afer (Peters, 1864), P. asper (Boulenger, 1911), P. burchelli Smith, 1841, P. burgi (Boulenger, 1911), P. phlegethon (Barnard, 1938) and P. tenuis (Barnard, 1938), were examined by conventional Giemsa staining and described. All six karyotypes have 2n = 100 chromosomes, dominated by biarmed chromosomes, as does the only other member of the genus, P. quathlambae (Barnard, 1938). Sex-related intraspecific karyotype variation was not found. The shared chromosome numbers and general similarity of the karyotypes (FN = 186–192) provide a new synapomorphy to support their monophyly, which is already indicated by anatomical and mtDNA markers. Karyotype evolution within the genus has been accompanied by chromosomal inversions and centromeric shifts. Comparison of the diploid number found in Pseudobarbus with other African barbine cyprinines, which have in the region of 2n=50 and lower FNs, suggests a tetraploid evolutionary origin of the genus, possibly by allotetraploidy
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PPARγ agonists negatively regulate αIIbβ3 integrin outside-in signalling and platelet function through upregulation of protein kinase A activity
BACKGROUND:
Agonists for the peroxisome proliferator activated receptor PPARγ, have been shown to have inhibitory effects on platelet activity following stimulation by GPVI and GPCR agonists.
OBJECTIVES:
Profound effects on thrombus formation led us to suspect a role for PPARγ agonists in the regulation of integrin αIIbβ3 mediated signalling. Both GPVI and GPCR signalling pathways lead to αIIbβ3 activation, and signalling through αIIbβ3 plays a critical role in platelet function and normal haemostasis.
METHODS:
The effects of PPARγ agonists on the regulation of αIIbβ3 outside-in signalling was determined by monitoring the ability of platelets to adhere and spread on fibrinogen and undergo clot retraction. Effects on signalling components downstream of αIIbβ3 activation were also determined following adhesion to fibrinogen by western blotting.
RESULTS:
Treatment of platelets with PPARγ agonists inhibited platelet adhesion and spreading on fibrinogen and diminished clot retraction. A reduction in phosphorylation of several components of αIIbβ3 signalling, including the integrin β3 subunit, Syk, PLCγ2, FAK and Akt was also observed as a result of reduced interaction of the integrin β3 subunit with Gα13. Studies of VASP phosphorylation revealed that this was a due to an increase in PKA activity following treatment with PPARγ receptor agonists.
CONCLUSIONS:
This study provides further evidence for anti-platelet actions of PPARγ agonists, identifies a negative regulatory role for PPARγ agonists in the control of integrin αIIbβ3 outside-in signalling, and provides a molecular basis by which the PPARγ agonists negatively regulate platelet activation and thrombus formation
Supercruiser Arrow HS-8
Technology in aeronautics has advanced dramatically since the last design of a production High Speed Civil Transport (HSCT) aircraft. Newly projected requirements call for a new High Speed Civil Transport aircraft with a range of approximately 550 nm and at least 275 passenger capacity. The aircraft must be affordable and marketable. The new HSCT must be able to sustain long-duration flights and to absorb the abuse of daily operation. The new aircraft must be safe and simple to fly and require a minimum amount of maintenance. This aircraft must meet FAA certification criteria of FAR Part 25 and environmental constraints. Several design configurations were examined and two designs were selected for further investigation. The first design employs the delta planform wings and conventional empennage layout. The other design uses a swing wing layout and conventional empennage. Other engineering challenges, including materials and propulsion are also discussed. At a cruise flight speed between Mach 2.2 and Mach 3.0, no current generation of materials can endure the thermal loading of supersonic flight and satisfy the stringent weight requirements. A new generation of lightweight composite materials must be developed for the HSCT. With the enforcement of stage 3 noise restrictions, these new engines must be able to propel the aircraft and satisfy the noise limit. The engine with the most promise is the variable cycle engine. At low subsonic speeds the engine operates like a turbofan engine, providing the most efficient performance. At higher speeds the variable cycle engine operates as a turbojet power plant. The two large engine manufacturers, General Electric and Pratt & Whitney in the United States, are combining forces to make the variable cycle engine a reality
A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)
Meeting abstrac
Karyology of the redfin minnows, genus Pseudobarbus Smith, 1841 (Teleostei: Cyprinidae): one of the evolutionarily tetraploid lineages of South African barbines
The karyotypes of six species of Pseudobarbus Smith, 1841, namely P. afer (Peters, 1864), P. asper (Boulenger, 1911), P. burchelli Smith, 1841, P. burgi (Boulenger, 1911), P. phlegethon (Barnard, 1938) and P. tenuis (Barnard, 1938), were examined by conventional Giemsa staining and described. All six karyotypes have 2n = 100 chromosomes, dominated by biarmed chromosomes, as does the only other member of the genus, P. quathlambae (Barnard, 1938). Sex-related intraspecific karyotype variation was not found. The shared chromosome numbers and general similarity of the karyotypes (FN = 186–192) provide a new synapomorphy to support their monophyly, which is already indicated by anatomical and mtDNA markers. Karyotype evolution within the genus has been accompanied by chromosomal inversions and centromeric shifts. Comparison of the diploid number found in Pseudobarbus with other African barbine cyprinines, which have in the region of 2n=50 and lower FNs, suggests a tetraploid evolutionary origin of the genus, possibly by allotetraploidy.Key words: Pseudobarbus, Barbinae, tetraploidy, cytogenetics, karyotyp
Multiple origins of polyploidy in the phylogeny of southern African barbs (Cyprinidae) as inferred from mtDNA markers
International audienceThe cyprinid genus Barbus, with more than 800 nominal species, is an apparently polyphyletic assemblage to which a number of unrelated species, groups and/or assemblages have been assigned. It includes species that exhibit three different ploidy levels: diploid, tetraploid and hexaploid. Several lineages of the family Cyprinidae constitute a major component of the African freshwater ichthyofauna, having about 500 species, and fishes assigned to the genus 'Barbus' have the most species on the continent. We used complete sequences of the mitochondrial cytochrome b gene in order to infer phylogenetic relationships between diploid, tetraploid and hexaploid species of 'Barbus' occurring in southern Africa, the only region where representatives of all of the three ploidy levels occur. The results indicate that most of the lineages are incorrectly classified in the genus 'Barbus'. The southern African tetraploids probably originated from southern African diploids. They constitute a monophyletic group distinct from tetraploids occurring in the Euro-Mediterranean region (Barbus sensu stricto). The 'small' African diploid species seem to be paraphyletic, while the 'large' African hexaploid barbs species are of a single, recent origin and form a monophyletic group. The evidence of multiple, independent origins of polyploidy occurring in the African cyprinine cyprinids thus provides a significant contribution to the knowledge on the systematic diversity of these fishes, and warrants a thorough taxonomic reorganization of the genus
Exploring Continuous Pressure Input for Mobile Phones
The input capabilities of mobile phones are limited by their physical form factor. Approaches to augmenting those capabilities that expand the input space without negatively impacting size or weight are particularly desirable. We propose adding simple pressure sensors under the keypad buttons to provide multiple channels of continuous pressure input. Pressure input supports a larger and more interesting interaction space without some of the unusual or unwanted qualities of some other approaches. We describe an implementation of our pressure-augmented system and show a number of interaction techniques, some old and some new, facilitated by continual pressure. We contrast these techniques with previous sensor-augmentation devices and highlight notable differences and advantages
A retrospective cohort study of risk factors and outcomes in older patients admitted to an inner-city geriatric unit in London during first peak of COVID-19 pandemic.
PURPOSE: Compared to younger patients, coronavirus disease 2019 (COVID-19) clinical presentation in older people can be more heterogeneous and fatal. We aim to describe a cohort of older adults admitted in an inner-city London hospital during the first peak of the pandemic. METHODS: A retrospective observational study that enrolled older adults consecutively admitted into two geriatric wards with suspected or confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We collected socio-demographic data, comorbidities, symptoms at presentation and/or during admission, biochemical and radiological data and outcomes at 28 days. RESULTS: One hundred twenty-four patients were included, and 75% were > 80 years old. 19.5% of COVID-19 cases were judged to be hospital-acquired. More than half presented or developed typical symptoms, respiratory failure or fatigue. 46.8% were diagnosed with delirium, 24.2% with falls and dysphagia was present in 13.7%. The mortality rate was 29.8% and was higher among males, those > 80 years, patients with a higher grade of frailty, a history of dementia or chronic kidney disease, as well as those diagnosed with respiratory failure, acute kidney injury or hypernatremia. Independent predictors of mortality were male sex, age > 80 years, respiratory failure and hypernatremia. CONCLUSION: We have described a cohort of patients with SARS-CoV-2 infection in the first UK peak of the global pandemic. We found that these patients had significant frailty with multiple comorbidities. There was a high mortality and increased dependency and greater social care need in survivors
Bat Diversity at Ikh Nart Nature Reserve, Mongolia
Bats represent one of the least studied mammal groups in Mongolia, and
little is known about the distribution and ecology of species in the country.
We surveyed bats in Ikh Nart Nature Reserve, which lies at the intersection
of two ecozones in Mongolia, to determine the species present and obtain
preliminary data on habitat associations. We conducted mist net surveys
at 9 sites, including 4 at natural springs, 2 at human-made wells, and 3 at
sites without water, from June to August 2011. We captured 149 individuals
representing 3 species,
Myotis aurascens, Eptesicus gobiensis,
and
Vespertilio
sp. One species,
E.
gobiensis
, represents a new record for the reserve. We
captured all three species at sites near natural springs, only one species,
M.
aurascens,
at human-made well sites, and no bats at sites without water.
We also collected basic morphometric measurements for
M. aurascens
and
E. gobiensis
. Analysis of morphometric measurements for
M. aurascens
indicated some sexual dimorphisms. Our results provide a baseline estimate
of bats in Ikh Nart and suggest that bat diversity is greater than previously
thought. Our results also validate the presence of
E. gobiensis
and suggest that
the species we captured associate mainly with natural water sources
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