1,096 research outputs found
Preliminary OARE absolute acceleration measurements on STS-50
On-orbit Orbital Acceleration Research Experiment (OARE) data on STS-50 was examined in detail during a 2-day time period. Absolute acceleration levels were derived at the OARE location, the orbiter center-of-gravity, and at the STS-50 spacelab Crystal Growth Facility. The tri-axial OARE raw acceleration measurements (i.e., telemetered data) during the interval were filtered using a sliding trimmed mean filter in order to remove large acceleration spikes (e.g., thrusters) and reduce the noise. Twelve OARE measured biases in each acceleration channel during the 2-day interval were analyzed and applied to the filtered data. Similarly, the in situ measured x-axis scale factors in the sensor's most sensitive range were also analyzed and applied to the data. Due to equipment problem(s) on this flight, both y- and z- axis sensitive range scale factors were determined in a separate process (using the OARE maneuver data) and subsequently applied to the data. All known significant low-frequency corrections at the OARE location (i.e., both vertical and horizontal gravity-gradient, and rotational effects) were removed from the filtered data in order to produce the acceleration components at the orbiter's center-of-gravity, which are the aerodynamic signals along each body axes. Results indicate that there is a force of unknown origin being applied to the Orbiter in addition to the aerodynamic forces. The OARE instrument and all known gravitational and electromagnetic forces were reexamined, but none produce the observed effect. Thus, it is tentatively concluded that the Orbiter is creating the environment observed
The Active Management of Impending Cephalopelvic Disproportion in Nulliparous Women at Term: A Case Series
Background. The Active Management of Risk in Pregnancy at Term (AMOR-IPAT) protocol has been associated in several studies with significant reductions of group cesarean delivery rate. Present within each of these studies were nulliparous women with risk factors for cephalopelvic disproportion. Risk factors for cephalopelvic disproportion in nulliparous women are especially important because they represent the precursors for the most common indication for primary cesarean delivery. Cases. Three examples of exposure of urban nulliparous women to the AMOR-IPAT protocol are presented. Each woman's risk factor profile for Cephalopelvic Disproportion (CPD) was used to estimate her Upper Limit of Optimal Time of Vaginal Delivery for CPD (UL-OTDcpd). Labor management and clinical outcomes for each case are presented. A simple table summarizing induction rates and birth outcome rates of exposed versus nonexposed nulliparous women is also presented. Conclusion. Because the mode of delivery of the first birth substantially impacts birth options in later pregnancies, the impact of AMOR-IPAT on nulliparous patients is particularly important. Determining the UL-OTDcpd in nulliparous patients, and carefully inducing each patient who has not entered labor by her UL-OTDcpd, may be an effective way of lowering rates of cesarean delivery in nulliparous women
Darwin\u27s Bee-Trap: The Kinetics of Catasetum, a New World Orchid
The orchid genera Catasetum employs a hair-trigger activated, pollen release mechanism, which forcibly attaches pollen sacs onto foraging insects in the New World tropics. This remarkable adaptation was studied extensively by Charles Darwin and he termed this rapid response sensitiveness. Using high speed video cameras with a frame speed of 1000 fps, this rapid release was filmed and from the subsequent footage, velocity, speed, acceleration, force and kinetic energy were computed
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A multi-disciplinary Delphi method to identify consensus in the management of intracranial germ cell tumours
The management of intracranial germ-cell tumours is complex because of varied clinical presentations, tumour sites, treatments and outcomes, and the need for multidisciplinary input. Participants of the 2013 Third International CNS Germ Cell Tumour Symposium (Cambridge, UK) agreed to undertake a multidisciplinary Delphi process to identify consensus in the clinical management of intracranial germ-cell tumours. 77 delegates from the symposium were selected as suitable experts in the field and were invited to participate in the Delphi survey, of which 64 (83%) responded to the invitation. Invited participants represented multiple disciplines from Asia, Australasia, Europe, and the Americas. 38 consensus statements encompassing aspects of intracranial germ-cell tumour work-up, staging, treatment, and follow-up were prepared. To achieve consensus, statements required at least 70% agreement from at least 60% of respondents. Overall, 34 (89%) of 38 statements met consensus criteria. This international Delphi approach has defined key areas of consensus that will help guide and streamline clinical management of patients with intracranial germ-cell tumours. Additionally, the Delphi approach identified areas of different understanding and clinical practice internationally in the management of these tumours, areas which should be the focus of future collaborative studies. Such efforts should translate into improved patient outcomes.This is the accepted manuscript. It is currently embargoed pending publication
OARE flight maneuvers and calibration measurements on STS-58
The Orbital Acceleration Research Experiment (OARE), which has flown on STS-40, STS-50, and STS-58, contains a three axis accelerometer with a single, nonpendulous, electrostatically suspended proofmass which can resolve accelerations to the nano-g level. The experiment also contains a full calibration station to permit in situ bias and scale factor calibration. This on-orbit calibration capability eliminates the large uncertainty of ground-based calibrations encountered with accelerometers flown in the past on the orbiter, thus providing absolute acceleration measurement accuracy heretofore unachievable. This is the first time accelerometer scale factor measurements have been performed on orbit. A detailed analysis of the calibration process is given along with results of the calibration factors from the on-orbit OARE flight measurements on STS-58. In addition, the analysis of OARE flight maneuver data used to validate the scale factor measurements in the sensor's most sensitive range is also presented. Estimates on calibration uncertainties are discussed. This provides bounds on the STS-58 absolute acceleration measurements for future applications
Integrated Metabonomic-Proteomic Analysis of an Insect-Bacterial Symbiotic System
The health of animals, including humans, is dependent on their resident microbiota, but the complexity
of the microbial communities makes these associations difficult to study in most animals. Exceptionally,
the microbiology of the pea aphid Acyrthosiphon pisum is dominated by a single bacterium Buchnera
aphidicola (B. aphidicola). A 1H NMR-based metabonomic strategy was applied to investigate metabolic
profiles of aphids fed on a low essential amino acid diet and treated by antibiotic to eliminate B.
aphidicola. In addition, differential gel electrophoresis (DIGE) with mass spectrometry was utilized to
determine the alterations of proteins induced by these treatments. We found that these perturbations
resulted in significant changes to the abundance of 15 metabolites and 238 proteins. Ten (67%) of the
metabolites with altered abundance were amino acids, with nonessential amino acids increased and
essential amino acids decreased by both perturbations. Over-represented proteins in the perturbed
treatments included catabolic enzymes with roles in amino acid degradation and glycolysis, various
cuticular proteins, and a C-type lectin and regucalcin with candidate defensive roles. This analysis
demonstrates the central role of essential amino acid production in the relationship and identifies
candidate proteins and processes underpinning the function and persistence of the association
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Circulating microRNAs as biomarkers to assist the management of the malignant germ-cell-tumour subtype choriocarcinoma.
Germ-cell-tumours (GCTs) are heterogeneous and management is complex. The current conventional biomarkers, alpha-fetoprotein and human-chorionic-gonadotropin (HCG), have limited utility for diagnosis/follow-up as secretion is restricted to specific malignant-GCT subtypes and long half-life can make interpretation and clinical decision-making challenging. We sought to identify circulating microRNAs that reflected choriocarcinoma disease activity more accurately than HCG in a metastatic primary mediastinal nonseminomatous-GCT (PMNSGCT) case with elevated diagnostic serum HCG (>250,000U/L), consistent with pure choriocarcinoma. We undertook comprehensive microRNA profiling (n=754 microRNAs) using two 384-well TaqMan Low-Density-Array cards in 16 serum samples; 10 from PMNSGCT diagnosis/follow-up and six controls. Key findings underwent confirmatory qRT-PCR. We identified a serum panel of choriocarcinoma-specific ‘chromosome-19-microRNA-cluster’ (C19MC) microRNAs that were highly elevated at diagnosis but fell rapidly on treatment and normalised before the second full chemotherapy course. We also re-confirmed serum elevation of the previously identified malignant-GCT marker miR-371a-3p at diagnosis. These circulating microRNA markers reflected choriocarcinoma disease activity more accurately than serum HCG and real-time knowledge would have assisted clinical decision-making. With further study, these microRNA markers will facilitate future management of such patients and are likely to result in improved outcomes.Acknowledgment of research support: The authors acknowledge grant funding from the St. Baldrick’s Foundation [reference 358099], the Isaac Newton Trust [reference 15.40f], the Medical Research Council [reference MR/R001146/1] and Addenbrooke’s Charitable Trust [reference 23/17 B (iv)]. We are grateful for support from the Max Williamson Fund and from Christiane and Alan Hodson, in memory of their daughter Olivia. The funders were not involved in study design, data collection or interpretation, or decision to submit for publication
A comparison of collision cross section values obtained via travelling wave ion mobility-mass spectrometry and ultra high performance liquid chromatography-ion mobility-mass spectrometry : application to the characterisation of metabolites in rat urine
A comprehensive Collision Cross Section (CCS) library was obtained via Travelling Wave Ion Guide mobility measurements through direct infusion (DI). The library consists of CCS and Mass Spectral (MS) data in negative and positive ElectroSpray Ionisation (ESI) mode for 463 and 479 endogenous metabolites, respectively. For both ionisation modes combined, TWCCSN2 data were obtained for 542 non-redundant metabolites. These data were acquired on two different ion mobility enabled orthogonal acceleration QToF MS systems in two different laboratories, with the majority of the resulting TWCCSN2 values (from detected compounds) found to be within 1% of one another. Validation of these results against two independent, external TWCCSN2 data sources and predicted TWCCSN2 values indicated to be within 1-2% of these other values. The same metabolites were then analysed using a rapid reversed-phase ultra (high) performance liquid chromatographic (U(H)PLC) separation combined with IM and MS (IM-MS) thus providing retention time (tr), m/z and TWCCSN2 values (with the latter compared with the DI-IM-MS data). Analytes for which TWCCSN2 values were obtained by U(H)PLC-IM-MS showed good agreement with the results obtained from DI-IM-MS. The repeatability of the TWCCSN2 values obtained for these metabolites on the different ion mobility QToF systems, using either DI or LC, encouraged the further evaluation of the U(H)PLC-IM-MS approach via the analysis of samples of rat urine, from control and methotrexate-treated animals, in order to assess the potential of the approach for metabolite identification and profiling in metabolic phenotyping studies. Based on the database derived from the standards 63 metabolites were identified in rat urine, using positive ESI, based on the combination of tr, TWCCSN2 and MS data.</p
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