4,216 research outputs found

    Obituary: Arthur Cruickshank 1932 - 2011. A native Gondwanan, who studied the former continent's fossil tetrapods

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    Dr Arthur Richard Ivor Cruickshank died on 4th December 2011, aged 79, in the Borders General Hospital, Melrose, Scotland. Arthur Cruickshank was part of the post-war generation of palaeontologists who laid the foundations on which today’s researchers build. Appropriately for someone from an expatriate Scots family living in Kenya, much of his work was on the extinct reptiles of the great southern palaeocontinent of Gondwana

    HZE beam transport in multilayered materials

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    A nonperturbative analytic solution of the high charge and energy (HZE) Green's function is used to implement a computer code for laboratory ion beam transport in multiple-layered materials. The code is established to operate on the Langley nuclear fragmentation model used in space engineering applications. Computational procedures are established to generate linear energy transfer (LET) distributions for a specified ion beam and target for comparison with experimental measurement. Comparison with Fe-56 ion with Pb-Al and Pb-(CH2)(x) targets shows reasonable agreement

    A cnidarian homologue of an insect gustatory receptor functions in developmental body patterning.

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    Insect gustatory and odorant receptors (GRs and ORs) form a superfamily of novel transmembrane proteins, which are expressed in chemosensory neurons that detect environmental stimuli. Here we identify homologues of GRs (Gustatory receptor-like (Grl) genes) in genomes across Protostomia, Deuterostomia and non-Bilateria. Surprisingly, two Grls in the cnidarian Nematostella vectensis, NvecGrl1 and NvecGrl2, are expressed early in development, in the blastula and gastrula, but not at later stages when a putative chemosensory organ forms. NvecGrl1 transcripts are detected around the aboral pole, considered the equivalent to the head-forming region of Bilateria. Morpholino-mediated knockdown of NvecGrl1 causes developmental patterning defects of this region, leading to animals lacking the apical sensory organ. A deuterostome Grl from the sea urchin Strongylocentrotus purpuratus displays similar patterns of developmental expression. These results reveal an early evolutionary origin of the insect chemosensory receptor family and raise the possibility that their ancestral role was in embryonic development

    Operationalizing Sustainability as a Safe Policy Space

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    It is possible to frame sustainability as occurring when the global or local system is within a set of limits and boundaries, such as the concept of safe operating spaces within planetary boundaries. However, such framings, whilst highly useful conceptually, have been difficult to translate into operation, especially in the development of policies. Here we show how it is possible to define a safe operating space, bounded by sets of constraints. These constraints can be of a variety of forms (e.g., income, or biodiversity), and, importantly, they need not all be converted to a single common metric such as money. The challenge is to identify a set of policy options that define the “safe policy space” which maintains the system within the safe operating space defined by boundaries. A formal methodology, Co-Viability Analysis (CVA), can be used to do this. This provides a coherent framework to operationalize sustainability and has a number of extra advantages. First, defining a safe policy space allows for a political choice of which policies and so is not prescriptive—such as would be the case if a single policy option were defined. Secondly, by allowing each boundary to be defined with its own scale of measurement, it avoids the necessity of having to value natural capital or ecosystem services in financial terms. This framework, therefore, has the potential to allow decision-makers to genuinely meet the needs of their people, now and in the future

    Wearable Positive End-Expiratory Pressure Valve Improves Exercise Performance

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    Positive end-expiratory pressure (PEEP) provides benefits to pulmonary patients, yet effects in healthy, exercising adults are unknown. PURPOSE: We designed two experiments (EXP) to test a novel PEEP (4.2 cmH2O PEEP) mouthpiece (PMP) on maximal cycling performance of physically active volunteers. METHODS: EXP-1 PMP vs. control (CON) mouthpiece (N=9, Age=30±2 yr, Weight=72.2±3.7 kg, BMI=24.4±1.2, 5♂); and EXP-2 PMP vs. no mouthpiece (NMP) (N=10, Age=27±1 yr, Weight=76.7±3.6 kg, BMI=23.9±0.8, ♂). Exercise test procedures for both experiments were identical. On Day 1, under the first mouthpiece condition assigned at random subjects performed graded exercise cycling testing (GXT) (Corival®) for VO2peak (ml*kg*min-1), oxygen pulse (mlO2*bt) (O2pulse), GXT endurance time (s) (GXT-T), and VO2(ml*kg*min-1)-at-ventilatory-threshold (VO2 @VT). Subjects returned 72 h later (Day 2), to complete an endurance ride timed (s)to exhaustion (VTER) at an intensity equivalent to their VO2 @VT power (W). One week later, subjects repeated exercise testing protocols (Days 3 & 4, time-of-day controlled) under the alternate mouthpiece condition. RESULTS: Selected outcomes were as follows (paired T-test, *PMP vs. CON, respectively: VO2peak=45.2±2.4* vs. 42.4±2.3; VO2@VT=33.7±2.0 vs. 32.3±1.6; GXT-T=521.7±73.4* vs. 495.3±72.8; VTER=846.2±166.0 vs. 743.1±124.7; O2pulse=24.5±1.4* vs. 23.1±1.3. PMP vs. NMP, respectively: VO2peak=43.3±1.6* vs. 41.7±1.6; VO2@AT=31.1±1.2* vs. 29.1±1.3; GXT-T=511.7*±49.6 vs. 486.4±49.6; VTER 872.4±134.0 vs. 792.9 ± 122.4; O2pulse=24.1±0.9* vs. 23.4±0.9. CONCLUSION: These results demonstrate that the novel PEEP mouthpiece we tested confers a significant performance benefit to cyclists completing high intensity exercise. By extension, it is likely to be an advantage in any physical activity having an aerobic component

    Angular momentum sharing in dissipative collisions

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    Light charged particles emitted by the projectile-like fragment were measured in the direct and reverse collision of 93^{93}Nb and 116^{116}Sn at 25 AMeV. The experimental multiplicities of Hydrogen and Helium particles as a function of the primary mass of the emitting fragment show evidence for a correlation with net mass transfer. The ratio of Hydrogen and Helium multiplicities points to a dependence of the angular momentum sharing on the net mass transfer.Comment: 8 pages, 2 figure

    Effect of different UCOE-promoter combinations in creation of engineered cell lines for the production of Factor VIII

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    <p>Abstract</p> <p>Background</p> <p>The most common approach used in generating cell lines for the production of therapetic proteins relies on gene amplification induced by a drug resistance gene e. g., DHFR and glutamine synthetase. Practically, this results in screening large number of clones for the one that expresses high levels of the biologic in a stable manner. The inefficiency of mammalian vector systems to express proteins in a stable manner typically involves silencing of the exogenous gene resulting from modifications such as methylation of CpG DNA sequences, histone deacetylation and chromatin condensation. The use of un-methylated CpG island fragments from housekeeping genes referred to as UCOE (ubiquitous chromatin opening elements) in plasmid vectors is now well established for increased stability of transgene expression. However, few UCOE-promoter combinations have been studied to date and in this report we have tested 14 different combinations.</p> <p>Findings</p> <p>In this report we describe studies with two different UCOEs (the 1.5 Kb human RNP fragment and the 3.2 Kb mouse RPS3 fragment) in combination with various promoters to express a large protein (B domain deleted factor VIII; BDD-FVIII) in a production cell line, BHK21. We show here that there are differences in expression of BDD-FVIII by the different UCOE-promoter combinations in both attached and serum free suspension adapted cells. In all cases, the 1.5 Kb human RNP UCOE performed better in expressing BDD-FVIII than their corresponding 3.2 Kb mouse RPS3 UCOE. Surprisingly, in certain scenarios described here, expression from a number of promoters was equivalent or higher than the commonly used and industry standard human CMV promoter.</p> <p>Conclusion</p> <p>This study indicates that certain UCOE-promoter combinations are better than others in expressing the BDD-FVIII protein in a stable manner in BHK21 cells. An empirical study such as this is required to determine the best combination of UCOE-promoter in a vector for a particular production cell line.</p

    Design and rationale of the high-sensitivity Troponin T Rules Out Acute Cardiac Insufficiency Trial

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    BACKGROUND: Acute heart failure (AHF) is a common presentation in the Emergency Department (ED), and most patients are admitted to the hospital. Identification of patients with AHF who have a low risk of adverse events and are suitable for discharge from the ED is difficult, and an objective tool would be useful. METHODS: The highly sensitive Troponin T Rules Out Acute Cardiac Insufficiency Trial (TACIT) will enroll ED patients being treated for AHF. Patients will undergo standard ED evaluation and treatment. High-sensitivity troponin T (hsTnT) will be drawn at the time of enrollment and 3 hours after the initial draw. The initial hsTnT draw will be no more than 3 hours after initiation of therapy for AHF (vasodilator, loop diuretic, noninvasive ventilation). Treating clinicians will be blinded to hsTnT results. We will assess whether hsTnT, as a single measurement or in series, can accurately predict patients at low risk of short-term adverse events. CONCLUSION: TACIT will explore the value of hsTnT measurements in isolation, or in combination with other markers of disease severity, for the identification of ED patients with AHF who are at low risk of short-term adverse events
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