9,092 research outputs found
Comparison of calculated and experimental cascade performance for controlled-diffusion compressor stator blading
The mid-span section of a previously reported controlled-diffusion compressor stator has been experimentally evaluated in cascade. Measurements are taken over a range of incidence angles for blade chord Reynolds numbers from 470,000 to 690,000. Blade chord length is 12.7 cm, aspect ratio is 2.0, and solidity is 1.67. Measurements include conventional cascade performance parameters as well as blade surface pressures. Computations are made for the inviscid flow field, surface boundary layers, and loss for several of the blade inlet angle conditions, are compared against corresponding data
Motilin receptor (version 2020.4) in the IUPHAR/BPS Guide to Pharmacology Database
Motilin receptors (provisional nomenclature) are activated by motilin, a 22 amino-acid peptide derived from a precursor (MLN, P12872), which may also generate a motilin-associated peptide. Activation of these receptors by endogenous motilin released from endocrine cells within the mucosa of the duodenum during fasting, induces propulsive phase III movements, part of the gastric migrating motor complex, and promotes the sensation of hunger. Drugs and other non-peptide compounds which activate the motilin receptor may generate a more long-lasting ability to increase cholinergic activity within the upper gut, to promote gastrointestinal motility; this activity is suggested to be responsible for the gastrointestinal prokinetic effects of certain macrolide antibiotics (often called motilides; e.g. erythromycin), although for many of these molecules the evidence is sparse. Relatively high doses of these compounds may induce vomiting and in humans, nausea
An assessment of the effects of neurokinin<sub>1</sub> receptor antagonism against nausea and vomiting: Relative efficacy, sites of action and lessons for future drug development.
A ābroad-spectrumā anti-vomiting effect of neurokinin1 receptor antagonists (NK1RA), shown in preclinical animal studies, has been supported by a more limited range of clinical studies in different indications. However, this review suggests that compared with vomiting, the self-reported sensation of nausea is less affected or possibly unaffected (depending on the stimulus) by NK1 receptor antagonism, a common finding for āanti-emeticsā.
The stimulus-independent effects of NK1RAs against vomiting are explicable by actions within the central pattern generator (CPG; ventral brainstem) and the nucleus tractus solitarius (NTS; dorsal brainstem), with additional effects on vagal afferent activity for certain stimuli (e.g., highly emetogenic chemotherapy). The CPG and NTS neurones are multifunctional so the notable lack of obvious effects of NK1RAs on other reflexes mediated by the same neurones suggests that their anti-vomiting action is dependent on the activation state of the pathway leading to vomiting.
Nausea requires activation of cerebral pathways by projection of information from the NTS. Although NK1 receptors are present in cerebral nuclei implicated in nausea, and imaging studies show very high receptor occupancy at clinically used doses, the variable or limited ability of NK1RAs to inhibit nausea emphasises (a) our inadequate understanding of the mechanisms of nausea and (b) that classification of a drug as an āanti-emeticā may give a false impression of efficacy against nausea versus vomiting.
We discuss the potential mechanisms for the differential efficacy of NK1RA and the implications for future development of drugs which can effectively treat nausea, an area of unmet clinical need
Motilin receptor in GtoPdb v.2021.2
Motilin receptors (provisional nomenclature) are activated by motilin, a 22 amino-acid peptide derived from a precursor (MLN, P12872), which may also generate a motilin-associated peptide. There are significant species differences in the structure of motilin and its receptor. In humans and large mammals such as dog, activation of these receptors by motilin released from endocrine cells in the duodenal mucosa during fasting, induces propulsive phase III movements. This activity is associated with promoting hunger in humans. Drugs and other non-peptide compounds which activate the motilin receptor may generate a more long-lasting ability to increase cholinergic activity within the upper gut, to promote gastrointestinal motility; this activity is suggested to be responsible for the gastrointestinal prokinetic effects of certain macrolide antibiotics (often called motilides; e.g. erythromycin, azithromycin), although for many of these molecules the evidence is sparse. Relatively high doses may induce vomiting and in humans, nausea
Automated mound detection using LiDAR and Object-Based Image Analysis in Beaufort County, SC
The study of prehistoric anthropogenic mounded featuresā earthen mounds, shell heaps, and shell rings ā in the American Southeast is stymied by the spotty distribution of systematic surveys across the region. Many extant, yet unidentified, archaeological mound features continue to evade detection due to the heavily forested canopies that occupy large areas of the region, making pedestrian surveys difficult and preventing aerial observation. The use of object-based image analysis (OBIA) as a tool for analysing light detection and ranging (LiDAR) data, however, offers an inexpensive opportunity to address this challenge. Using publicly available LiDAR data from Beaufort County, South Carolina and an OBIA approach that incorporates morphometric classification and statistical template matching, we systematically identify over 150 previously undetected archaeological mound features. This result improves our overall knowledge of settlement patterns by providing a systematic knowledge about prehistoric landscapes
On ionization and luminescence in flames
An explanation based upon reaction kinetics is presented to account for the deviation of measured ionization levels obtained from reflection experiments from the values computed assuming chemical equilibrium. The heat transfer to the unburned fuel is also considered
Out of plane analysis for composite structures
Simple two dimensional analysis techniques were developed to aid in the design of strong joints for integrally stiffened/bonded composite structures subjected to out of plane loads. It was found that most out of plane failures were due to induced stresses arising from rapid changes in load path direction or geometry, induced stresses due to changes in geometry caused by buckling, or direct stresses produced by fuel pressure or bearing loads. While the analysis techniques were developed to address a great variety of out of plane loading conditions, they were primarily derived to address the conditions described above. The methods were developed and verified using existing element test data. The methods were demonstrated using the data from a test failure of a high strain wingbox that was designed, built, and tested under a previous program. Subsequently, a set of design guidelines were assembled to assist in the design of safe, strong integral composite structures using the analysis techniques developed
The Integration of Lidar and Legacy Datasets Provides Improved Explanations for the Spatial Patterning of Shell Rings in the American Southeast
Archaeologists have struggled to combine remotely sensed datasets with preexisting information for landscape-level analyses. In the
American Southeast, for example, analyses of lidar data using automated feature extraction algorithms have led to the identification of over
40 potential new pre-European-contact Native American shell ring deposits in Beaufort County, South Carolina. Such datasets are vital for understanding settlement distributions, yet a comprehensive assessment requires remotely sensed and previously surveyed archaeological data. Here, we use legacy data and airborne lidar-derived information to conduct a series of point pattern analyses using spatial models that we designed to assess the factors that best explain the location of shell rings. The results reveal that ring deposit locations are highly clustered and best explained through a combination of environmental conditions such as distance to water and elevation as well as social factors
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