778 research outputs found
Volatile Liquid Detection by Terahertz Technologies
The prospect of being able to move through security without the inconvenience of separating liquids from bags is an exciting one for passengers, and there are important operational benefits for airports as well. Here, two terahertz (THz) systems, 100 GHz sub-THz line scanner and attenuation total reflection-based THz time domain spectroscopy (TDS), have been used to demonstrate the capability of identifying different liquid samples. Liquid samplesâ THz complex permittivities are measured and their differences have contributed to the variation of 100 GHz 2D images of volatile liquids with different volumes inside of cannister bottles. The acquired attenuation images at 100 GHz can easily be used to distinguish highly absorbed liquids (Water, Ethanol, Fuel Treatment Chemicals) and low loss liquids (Petrol, Diesel, Kerosene and Universal Bottle Cleaner). The results give a promising feasibility for mm-wave imager and THz spectroscopy to efficiently identify different volatile liquids
Doxycycline delays aneurysm rupture in a mouse model of Marfan syndrome
ObjectivesThoracic aneurysms are the main cardiovascular complication of Marfan syndrome (MFS) resulting in premature death. MFS has been associated with mutations of the gene encoding fibrillin-1 (FBN1), a major constituent of the elastic fibers. Matrix metalloproteinases (MMPs) are important in the pathogenesis of abdominal aortic aneurysms but their precise role in MFS is not clear. Doxycycline is a nonspecific MMP inhibitor. The objective of the study was to determine whether docycycline can attenuate matrix degradation and prolong the survival of mice with MFS.MethodsThe study employed a well-characterized animal model of MFS, namely fibrillin-1 under-expressing mice (mgR/mgR mice) that die spontaneously from rupture of the thoracic aorta between 2 to 4 months of age. Mutant and wild type mice were given doxycycline in their drinking water at a concentration designed to provide 100 mg/kg/day beginning at postnatal day (PD) 1, whereas control mice were given water. Treated mice were divided into two groups. One group of animals was followed until death or for 7 months to determine lifespan. In the second group of mice, the ascending thoracic aortas were collected for histological analysis (H&E staining, trichrome staining) and zymography for examining MMP-2 and MMP-9 levels at 6 weeks.ResultsMMP-2 and MMP-9 levels were higher in the thoracic aorta of mgR/mgR mice compared with wild type littermates. Doxycycline-treated mgR/mgR mice lived 132 ± 14.6 days (n = 16) or significantly longer than untreated mutant mice (79 ± 6.7 days, n = 30) (P < 0.01). Connective tissue staining showed that doxycycline treatment decreased elastic fiber degradation in mgR/mgR mice. Furthermore, mgR/mgR mice treated with doxycycline had lower MMP-2 and MMP-9 levels compared with untreated mgR/mgR mice.ConclusionsThis study demonstrates that doxycycline significantly delays aneurysm rupture in MFS-like mice by inhibiting expression of tissue MMP-2 and MMP-9 and thus, degradation of the elastic matrix. The results suggest that MMPs contribute to the progression of thoracic aneurysm in MFS and that doxycycline has the potential to significantly alter the course of the disease.Clinical RelevanceAortic aneurysms are the main cardiovascular complication of Marfan syndrome (MFS) resulting in premature death. ÎČ-blockers offer some benefit but do not address the underlying cause of the progressive aortic degradation. Medical treatment that actually targets recently identified pathogenic factors leading to progressive matrix destruction could significantly impact the clinical course of the disease. A recent study using a mouse model of MFS has demonstrated that TGF- ÎČ antibodies or the angiotensin II type I receptor (AT1) antagonist losartan can both effectively rescue aneurysm progression. We have found that doxycycline, a nonspecific inhibitor of matrix metalloproteinases (MMPs), can decrease elastin degradation and prolong the lifespan of genetically engineered mice that mimic the human disease process. Based on these results, further testing may be warranted to determine if doxycycline could favorable impact the natural history of Marfan syndrome
Coffee and Caffeine Ingestion Have Little Effect on Repeated Sprint Cycling in Relatively Untrained Males
The present study investigated the effect of ingesting caffeine-dose-matched anhydrous caffeine or coffee on the performance of repeated sprints. Twelve recreationally active males (mean ± SD age: 22 ± 2 years, height: 1.78 ± 0.07 m, body mass: 81 ± 16 kg) completed eighteen 4 s sprints with 116 s recovery on a cycle ergometer on four separate occasions in a double-blind, randomised, counterbalanced crossover design. Participants ingested either 3 mg·kgâ1 of caffeine (CAF), 0.09 g·kgâ1 coffee, which provided 3 mg·kgâ1 of caffeine (COF), a taste-matched placebo beverage (PLA), or a control condition (CON) 45 min prior to commencing the exercise protocol. Peak and mean power output and rating of perceived exertion (RPE) were recorded for each sprint. There were no significant differences in peak power output (CAF: 949 ± 199 W, COF: 949 ± 174 W, PLA: 971 ± 149 W and CON: 975 ± 170 W; p = 0.872; η P 2 = 0.02) or mean power output (CAF: 873 ± 172 W, COF: 862 ± 44 W, PLA: 887 ± 119 W and CON: 892 ± 143 W; p = 0.819; η P 2 = 0.03) between experimental conditions. Mean RPE was similar for all trials (CAF: 11 ± 2, COF: 11 ± 2, PLA: 11 ± 2 and CON: 11 ± 2; p = 0.927; η P 2 = 0.01). Neither the ingestion of COF or CAF improved repeated sprint cycling performance in relatively untrained males
Volatile Liquid Detection by Terahertz Technologies
From Frontiers via Jisc Publications RouterHistory: received 2020-12-08, collection 2021, accepted 2021-02-11, epub 2021-04-08Publication status: PublishedThe prospect of being able to move through security without the inconvenience of separating liquids from bags is an exciting one for passengers, and there are important operational benefits for airports as well. Here, two terahertz (THz) systems, 100 GHz sub-THz line scanner and attenuation total reflection-based THz time domain spectroscopy (TDS), have been used to demonstrate the capability of identifying different liquid samples. Liquid samplesâ THz complex permittivities are measured and their differences have contributed to the variation of 100 GHz 2D images of volatile liquids with different volumes inside of cannister bottles. The acquired attenuation images at 100 GHz can easily be used to distinguish highly absorbed liquids (Water, Ethanol, Fuel Treatment Chemicals) and low loss liquids (Petrol, Diesel, Kerosene and Universal Bottle Cleaner). The results give a promising feasibility for mm-wave imager and THz spectroscopy to efficiently identify different volatile liquids
Using botanic gardens and arboreta to help identify urban trees for the future
Societal Impact StatementDiversification of urban forests is essential to enhance their resilience to future biotic threats as well as those posed by a changing climate. Arboreta and botanic gardens host a wide range of plant material that can be evaluated to inform tree selection policy. This study demonstrates that plant functional traits, such as the water potential at leaf turgor loss, can be highly instructive when developing evidence-based recommendations for urban environments. However, if botanic collections are to fulfil a critical role in understanding plant response to environment, they should not be managed solely as visitor attractions but must have scientific objectives at the forefront of management policy.SummaryArboreta and botanic gardens host a multitude of species that can be utilized in research focused on improving diversity within urban forests. Higher tree species diversity will enhance the resilience of urban forests to abiotic and biotic threats and help deliver strategies that foster sustainable communities. Consequently, this study aims to demonstrate the value of botanic collections as a resource for research into tree species selection for more resilient urban landscapes. As water stress is a major constraint for trees in urban environments, understanding the drought tolerance of species is essential for urban tree selection. This study evaluates a key functional trait relating to drought tolerance. Using vapor pressure osmometry, the water potential at leaf turgor loss was evaluated for 96 species using plant material from seven botanic collections in North America and Europe. Leaf turgor loss contrasted widely in the temperate deciduous trees evaluated and, in summer, ranged from -1.7 MPa to -3.9 MPa. Significant differences in drought tolerance were also apparent across genera and closely related cultivars. Osmotic adjustment was shown to be a major physiological factor driving leaf turgor loss. A meta-analysis also demonstrated that leaf turgor loss was closely related to a drought-tolerance scale based on observations of tree performance under drought. Arboreta and botanic collections can play a vital role in the evaluation of plant material for urban environments, provided they are curated with scientific objectives at the forefront of management policy and are not managed purely as visitor attractions
Scaling of the B and D meson spectrum in lattice QCD
We give results for the and the meson spectrum using NRQCD on the
lattice in the quenched approximation. The masses of radially and orbitally
excited states are calculated as well as -wave hyperfine and -wave fine
structure. Radially excited -states are observed for the first time. Radial
and orbital excitation energies match well to experiment, as does the
strange-non-strange -wave splitting. We compare the light and heavy quark
mass dependence of various splittings to experiment. Our -results cover a
range in lattice spacings of more than a factor of two. Our -results are
from a single lattice spacing and we compare them to numbers in the literature
from finer lattices using other methods. We see no significant dependence of
physical results on the lattice spacing.
PACS: 11.15.Ha 12.38.Gc 14.40.Lb 14.40.NdComment: 78 pages, 29 tables, 30 figures Revised version. Minor corrections to
spelling and wordin
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Supporting knowledge translation through collaborative translational research initiatives: 'bridging' versus 'blurring' boundary-spanning approaches in the UK CLAHRC initiative
Recent policy initiatives in the UK and internationally have sought to promote knowledge translation between the 'producers' and 'users' of research. Within this paper we explore how boundary-spanning interventions used within such initiatives can support knowledge translation between diverse groups. Using qualitative data from a 3-year research study conducted from January 2010 to December 2012 of two case-sites drawn from the CLAHRC initiative in the UK, we distinguish two different approaches to supporting knowledge translation; a 'bridging' approach that involves designated roles, discrete events and activities to span the boundaries between communities, and a 'blurring' approach that de-emphasises the boundaries between groups, enabling a more continuous process of knowledge translation as part of day-to-day work-practices. In this paper, we identify and differentiate these boundary-spanning approaches and describe how they emerged from the context defined by the wider CLAHRC networks. This highlights the need to develop a more contextualised analysis of the boundary-spanning that underpins knowledge translation processes, relating this to the distinctive features of a particular case
Relevance of the JAK2V617F mutation in patients with deep vein thrombosis of the leg
Venous thromboembolism (VTE) can be the first presenting symptom in myeloproliferative neoplasms (MPN). Studies have demonstrated a high prevalence of the JAK2V617F mutation in patients with splanchnic vein thrombosis. Fewer studies have been done in patients with thrombosis outside the splanchnic area, showing a lower prevalence although the clinical relevance of the mutation in these patients, e.g., progression to overt MPN, remains unknown. The objective of this study was to determine the effect size of JAK2V617F in prospectively collected DNA samples of patients objectively diagnosed with deep vein thrombosis (DVT) of the leg and controls without DVT, with follow-up on JAK2V617F-positive patients to assess clinical relevance. Presence of JAK2V617F was determined in DNA samples from 187 patients with DVT and 201 controls, using quantitative RT-PCR. Hematological parameters were also analyzed. All initially JAK2V617F-positive patients were reassessed. Of 187 patients with DVT, 178 were analyzed for JAK2V617F, and in four (2.3%; 95% CI 0.1â4.4), JAK2V617F was present. Of 201 controls, 198 were analyzed; one was JAK2V617F positive (0.5%; 95% CI â0.5â1.5, OR 4.5; 95% CI 0.5â40.9). None had MPN features, nor upon reassessment after a median follow-up of 68.5Â months. Four JAK2V617F-positive patients with DVT and one control without DVT did not develop overt MPN after a median follow-up of nearly 6Â years. Thus, in patients with non-splanchnic venous thrombosis, JAK2V617F appears not to be clinically relevant
Managing software engineers and their knowledge
This chapter begins by reviewing the history of software engineering as a profession, especially the so-called software crisis and responses to it, to help focus on what it is that software engineers do. This leads into a discussion of the areas in software engineering that are problematic as a basis for considering knowledge management issues. Some of the previous work on knowledge management in software engineering is then examined, much of it not actually going under a knowledge management title, but rather âlearningâ or âexpertiseâ. The chapter goes on to consider the potential for knowledge management in software engineering and the different types of knowledge management solutions and strategies that might be adopted, and it touches on the crucial importance of cultural issues. It concludes with a list of challenges that knowledge management in software engineering needs to address
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