140 research outputs found
STUDY BY IMAGE ANALYSIS AND LASER-BASED DROPLET SIZE DISTRIBUTION MEASUREMENT OF THE INFLUENCE OF EIGHT ADJUVANTS ON THE SPRAY FORMATION FOR THREE AGRICULTURAL SPRAY NOZZLES
The liquid sheet characteristics as a function of the adjuvant were measured using digital images. The droplet size distribution was measured using a Malvern particle size analyser. It appears that the dynamical surface tension plays a critical role in the spray formation. Spray formulation containing Li-700, Silwet L-77, Flofix and Actirob are characterised by a lower dynamical surface tension than those containing Tensiofix D03, Trend 90, Frigate and Break-thru S240. For the three agricultural spray nozzles tested and in comparaison with pure water, the first group shortened the length of the liquid sheet before a perforation break-up mode when the second group lengthened it slightly before a wave disintegration break-up mode. The lengthening of the liquid sheet, is followed by a diminution of the VMD.RW-102
Why the energy landscape of barnase is hierarchical
We have used NMR and computational methods to characterize the dynamics of the ribonuclease barnase over a wide range of timescales in free and inhibitor-bound states. Using temperature- and denaturant-dependent measurements of chemical shift, we show that barnase undergoes frequent and highly populated hinge bending. Using relaxation dispersion, we characterize a slower and less populated motion with a rate of 750 ± 200 s-Âč, involving residues around the lip of the active site, which occurs in both free and bound states and therefore suggests conformational selection. Normal mode calculations characterize correlated hinge bending motions on a very rapid timescale. These three measurements are combined with previous measurements and molecular dynamics calculations on barnase to characterize its dynamic landscape on timescales from picoseconds to milliseconds and length scales from 0.1 to 2.5 nm. We show that barnase has two different large-scale fluctuations: one on a timescale of 10-âč-10-ⶠs that has no free energy barrier and is a hinge bending that is determined by the architecture of the protein; and one on a timescale of milliseconds (i.e., 750 s-Âč) that has a significant free energy barrier and starts from a partially hinge-bent conformation. These two motions can be described as hierarchical, in that the more highly populated faster motion provides a platform for the slower (less probable) motion. The implications are discussed. The use of temperature and denaturant is suggested as a simple and general way to characterize motions on the intermediate ns-ÎŒs timescale
Wireless Communication Networks for Gas Turbine Engine Testing
A new trend in the field of Aeronautical Engine Health Monitoring is the implementation of wireless sensor networks (WSNs) for data acquisition and condition monitoring to partially replace heavy and complex wiring harnesses, which limit the versatility of the monitoring process as well as creating practical deployment issues. Using wireless technologies instead of fixed wiring will fuel opportunities for reduced cabling, faster sensor and network deployment, increased data acquisition flexibility and reduced cable maintenance costs. However, embedding wireless technology into an aero engine (even in the ground testing application considered here) presents some very significant challenges, e.g. a harsh environment with a complex RF transmission environment, high sensor density and high data-rate. In this paper we discuss the results of the Wireless Data Acquisition in Gas Turbine Engine Testing (WIDAGATE) project, which aimed to design and simulate such a network to estimate network performance and de-risk the wireless techniques before the deployment
Integrating evolution into ecological modelling: accommodating phenotypic changes in agent based models.
PMCID: PMC3733718This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Evolutionary change is a characteristic of living organisms and forms one of the ways in which species adapt to changed conditions. However, most ecological models do not incorporate this ubiquitous phenomenon. We have developed a model that takes a 'phenotypic gambit' approach and focuses on changes in the frequency of phenotypes (which differ in timing of breeding and fecundity) within a population, using, as an example, seasonal breeding. Fitness per phenotype calculated as the individual's contribution to population growth on an annual basis coincide with the population dynamics per phenotype. Simplified model variants were explored to examine whether the complexity included in the model is justified. Outputs from the spatially implicit model underestimated the number of individuals across all phenotypes. When no phenotype transitions are included (i.e. offspring always inherit their parent's phenotype) numbers of all individuals are always underestimated. We conclude that by using a phenotypic gambit approach evolutionary dynamics can be incorporated into individual based models, and that all that is required is an understanding of the probability of offspring inheriting the parental phenotype
Chronic hand eczema in Europe:Patient experiences and perspectives (CHEPEP) in qualitative interviews
Background: Chronic hand eczema (CHE) is a very common skin disease among the European population. It causes itch and pain and, in more severe cases, seriously impairs hand functioning at work and in private life. Objectives: To explore perspectives of people with lived experience on CHE-related problems, wishes and goals. Methods: Following a qualitative approach, we conducted topic-guided interviews in five European countries and applied template analysis to identify recurrent themes among patients with CHE. Results: We interviewed 60 patients in seven outpatient dermatological and occupational medicine clinics in Croatia, Denmark, Germany, the Netherlands and Spain. Five main themes were identified: (1) knowledge about the disease and its course, (2) preventive behaviour, (3) hand eczema therapy, (4) impact on everyday life and (5) attitudes towards CHE and healthcare. Participants did not feel well informed about CHE, especially about causes, triggers and treatment options. Preventive measures were experienced as more or less effective but also cumbersome. Experiences with therapy were diverse. Treatment satisfaction depended on the results and on the perceived support from the treatment teams. Participants found it important to be taken seriously, to receive practical advice, to try out additional treatments or examinations, find new hope and have occupational perspectives. They wished that others could better understand the physical and emotional burden of CHE. Patient support groups were not mentioned. Participants found it important to learn to take care of themselves and accept life with CHE. Conclusions: Due to its annoying symptoms, high visibility and impaired functioning at work and in private life, CHE has a high emotional and social impact. Some people may require support to learn coping with CHE and its prevention. Patients wish for information about causes and triggers. They value physicians who listen to them and keep looking for solutions.</p
Characterizations of how species mediate ecosystem properties require more comprehensive functional effect descriptors
The importance of individual species in mediating ecosystem process and functioning is generally accepted, but categorical descriptors that summarize species-specific contributions to ecosystems tend to reference a limited number of biological traits and underestimate the importance of how organisms interact with their environment. Here, we show how three functionally contrasting sediment-dwelling marine invertebrates affect fluid and particle transport - important processes in mediating nutrient cycling - and use high-resolution reconstructions of burrow geometry to determine the extent and nature of biogenic modification. We find that individual functional effect descriptors fall short of being able to adequately characterize how species mediate the stocks and flows of important ecosystem properties and that, in contrary to common practice and understanding, they are not substitutable with one another because they emphasize different aspects of species activity and behavior. When information derived from these metrics is combined with knowledge of how species behave and modify their environment, however, detailed mechanistic information emerges that increases the likelihood that a species functional standing will be appropriately summarized. Our study provides evidence that more comprehensive functional effect descriptors are required if they are to be of value to those tasked with projecting how altered biodiversity will influence future ecosystems
Nasopharyngeal Myoepithelial Carcinoma Mimicking Nasopharyngeal Carcinoma
AbstractMyoepithelial carcinoma (malignant myoepithelioma) (MC) is a rare tumor, defined as a malignant salivary neoplasm composed almost exclusively of tumor cells with myoepithelial differentiation. It can arise in unusual location sites, such as the nasopharynx, and may be difficult to approach. Nasopharyngeal MC can sometimes present as a nasopharyngeal mass which may be mistaken for primary nasopharyngeal carcinoma (NPC). The treatment strategy for nasopharyngeal MC is different from NPC, and maximal surgical resection of the main lesion is still considered as the mainstay of therapy. Herein we present a 32-year-old man with a nasopharyngeal mass which was initially mistaken as NPC, and which was later confirmed as MC after a comprehensive review of the pathology
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