2,050 research outputs found
Modulation of foregut synaptic activity controls resorption of molting fluid during larval molts of the moth Manduca sexta
We examined the role of the foregut in the resorption of molting fluid (MF) from the exuvial space during the last larval-larval molt of the moth Manduca sexta. In intermolt larvae, the activity of the foregut is characterized by robust peristaltic contractions. With the onset of the molt, MF is secreted into the exuvial space where it digests and weakens the old cuticle. The appearance of MF in the exuvial space is accompanied by a dramatic reduction in the amplitude of the foregut contractions. Foregut peristalsis returned about halfway through the molt, followed shortly by the appearance of MF in the gut. These observations suggested that larvae use their foreguts to remove MF from the exuvial space. Animals whose foreguts were surgically inactivated did not resorb their MF and most failed to successfully shed their old cuticles. The reduction in foregut motility at the onset of the molt was correlated with a sharp decline in the amplitude of the excitatory junctional potentials. With the onset of the molt there was also a decline in the number of presynaptic terminals on the foregut that loaded with the activity-dependent dye FM1-43. In the second half of the molt, the appearance of MF in the foregut and the return of foregut motility was correlated with an increase in FM1-43 loading. These data reveal that during a larval-larval molt, vesicle release and/or recycling of the presynaptic endings on the foregut muscles is modulated to assure the proper timing of MF resorption
Comparing and combining physically-based and empirically-based approaches for estimating the hydrology of ungauged catchments
Examination of lunar scientific objectives and evaluation and development studies for possible post-Apollo period Semiannual status report, 1 Jul. - 31 Dec. 1970
Lunar seismic velocity models and lunar reverberation calculation
Wind tunnel testing of a full scale helicopter blade section with an upstream active Gurney flap
Wind tunnel tests were performed on an aerofoil section comparable to that of a full scale helicopter blade section with an upstream active Gurney flap in the framework of the European project CleanSky ITD Green RotorCraft. A modified NACA0012 profile was used, with 23 Kulite pressure transducers embedded in the profile’s surface and with an integrated actuator system for the Gurney flap. The Gurney flap, positioned at 95% of the chord length and with a deployed size of 1.3% of the chord length, extended the full span width of the section. The aerofoil was supported by a mounting system with automated control of the angle of attack. The effect of the Gurney flap is assessed for various deployment strategies. The test campaign carried out was successful. The aerodynamic behaviour can be extracted from the data and contains valuable information for validation of 2D numerical models developed by other partners in the project. The most important improvement of the setup for future use is the stabilisation of the inclinometer readings, which showed a significant amount of noise
Hydrological impacts of floodplain restoration: a case study of the River Cherwell, UK
International audienceThis paper investigates the impacts on floods of hypothetical changes to river channel geometry by construction or removal of embankments to prevent water spreading onto the floodplain at high flows. A numerical model is applied to the River Cherwell between Oxford and Banbury to simulate changes to flood hydrographs. Embanking the river increases the peak flows downstream by 50-150%. Restoring the river channel through the floodplain to pre-engineered dimensions reduces peak flow by around 10-15% and increases peak water levels within the floodplain by 0.5-1.6 m. These results suggest that floodplain rehabilitation, in terms of embankment removal or returning the channel to pre-engineered dimensions, can be a valuable part of the flood management strategy of a catchment. Both measures lead to increased inundation of the floodplain, which can be positive for ecological restoration. Keywords: floodplains, hydrological impacts, rehabilitation, flood frequenc
Chrysanthemum species used as food and medicine: Understanding quality differences on the global market
Background
Chrysanthemum flowers [Ch. x morifolium (Ramat.) Hemsl. and Ch. indicum L.] are a globally used and pharmacologically interesting botanical drug, however, with variable product quality.
Objective
We aim at understanding the chemical variability of primary material available commercially based on different origins and associated quality problems like contamination with heavy metals. This needs to be assessed in the context of the current regulations for this botanical drug and associated problems.
Material and Methods
15 C. indicum L. and 50 C. x morifolium (Ramat.) Hemsl., including a range of geographical cultivars recognized in China, samples from the USA, Europe and China were analyzed using High Performance Thin Layer Chromatography (HPTLC) to compare their general chemical profile. Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) was used to quantify heavy metal contamination.
Results
The: HPTLC fingerprints of C. indicum samples are clearly distinguishable from C. x morifolium. Fingerprints of samples from the same cultivars collected from markets in different countries (USA and China) show different patterns. Large variance of fingerprints within each cultivar group was observed. The heavy metal analysis showed excessive amounts of some harmful heavy metal in some commercial products with excessive cadmium being the most frequent problem.
Conclusions
The Chinese medicinal cultivars vary. Differences between samples sourced from the USA and China might be ascribable to geographical factors (e.g. soil composition), degradation during transport/storage or adulteration, but geographical differences should also be taken into account. Importantly, a much more detailed definition of the drug are needed for better quality control. In addition, with continuous contamination problem observed, a more widespread regulation is an essential requirement for better quality
Aseptic meningitis in a patient taking etanercept for rheumatoid arthritis: a case report
Background \ud
We report a case of a 53 year old lady recently commenced on etanercept, an anti-TNF (tumour necrosis factor) therapy for rheumatoid arthritis presenting with \ud
confusion, pyrexia and an erythematous rash. \ud
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Case presentation \ud
A lumbar puncture was highly suggestive of bacterial meningitis, but CSF cultures produced no growth, and polymerase chain reactions (PCR) for all previously reported bacterial, fungal and viral causes of meningitis were negative. \ud
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Conclusions \ud
This case report describes aseptic meningitis as a previously unreported complication of etanercept therapy, and serves as a reminder of the rare but potentially lifethreatening risk of serious infections in patients taking anti-TNF therapy for a variety of conditions
Plant loading uncertainties and their incorporation in probabilistic creep damage assessments
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