3,524 research outputs found
cRIsp: Crowdsourcing Representation Information to Support Preservation
In this paper, we describe a new collaborative approach to the collection of representation information to ensure long term access to digital content. Representation information is essential for successful rendering of digital content in the future. Manual collection and maintenance of representation information has so far proven to be highly resource intensive and is compounded by the massive scale of the challenge, especially for repositories with no format limitations. This solution combats these challenges by drawing upon the wisdom and knowledge of the crowd to identify online sources of representation information, which are then collected, classified, and managed using existing tools. We suggest that nominations can be harvested and preserved by participating established web archives, which themselves could obviously benefit from such extensive collections. This is a low cost, low resource approach to collecting essential representation information of widespread relevance
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Strain and temperature sensors using multimode optical fiber Bragg gratings and correlation signal processing
Multimode fiber optic Bragg grating sensors for
strain and temperature measurements using correlation signal processing methods have been developed. Two multimode Bragg grating sensors were fabricated in 62/125 m graded-index silica
multimode fiber; the first sensor was produced by the holographic method and the second sensor by the phase mask technique. The sensors have signal reflectivity of approximately 35% at peak
wavelengths of 835 nm and 859 nm, respectively.
Strain testing of both sensors has been done from 0 to 1000 ΌΔ and the temperature testing from 40 to 80°C. Strain and temperature sensitivity values are 0.55 pm/ΌΔ and 6 pm/°C, respectively.
The sensors are being applied in a power-by-light hydraulic valve monitoring system
Clinical presentation, auscultation recordings, ultrasonographic findings and treatment response of 12 adult cattle with chronic suppurative pneumonia: case study
Auscultation is considered the critical component of the veterinary clinical examination for the diagnosis of bovine respiratory disease but the accuracy with which adventitious sounds reflect underlying lung pathology remains largely unproven. Modern portable ultrasound machines provide the veterinary practitioner with an inexpensive, non-invasive tool with which to examine the pleural surfaces and superficial lung parenchyma. Simultaneous recording of sounds overlying normal lung and defined pathology allows critical assessment of auscultated sounds in the same animal removing confounding factors such as respiratory rate and thickness of the chest wall (body condition). Twelve cows, referred to the University of Edinburgh Veterinary School, were diagnosed with chronic suppurative pneumonia and enrolled into this prospective study to record and monitor lung sounds, ultrasonographic findings, and response to a standardised antibiotic treatment regimen. Most cows (8/12) had a normal rectal temperature on presentation but all cows had received antibiotic therapy at some time in the previous two weeks and six animals were receiving antibiotic treatment upon admission. All cattle were tachypnoeic (>40 breaths per minute) with frequent and productive coughing, halitosis, and a purulent nasal discharge most noticeable when the head was lowered. Ultrasonographic examination of the chest readily identified pathological changes consistent with severe lung pathology subsequently confirmed as chronic suppurative pneumonia in four cows at necropsy; eight cows recovered well after antibiotic treatment and were discharged two to six weeks after admission. It proved difficult to differentiate increased audibility of normal lung sounds due to tachypnoea from wheezes; coarse crackles were not commonly heard. In general, sounds were reduced in volume over consolidated lung relative to normal lung tissue situated dorsally. Rumen contraction sounds were commonly transmitted over areas of lung pathology. Trueperella (formerly Arcanobacterium) pyogenes was isolated from three of four lung tissue samples at necrospy. Treatment with procaine penicillin for 42 consecutive days resulted in marked improvement with return to normal appetite and improvement in body condition in 8 of 12 cows (67%) where lesions did not extend more than 10-15 cm above the level of the olecranon on both sides of the chest
Antibacterial Composite Materials Based on the Combination of Polyhydroxyalkanoates With Selenium and Strontium Co-substituted Hydroxyapatite for Bone Regeneration.
Due to the threat posed by the rapid growth in the resistance of microbial species to antibiotics, there is an urgent need to develop novel materials for biomedical applications capable of providing antibacterial properties without the use of such drugs. Bone healing represents one of the applications with the highest risk of postoperative infections, with potential serious complications in case of bacterial contaminations. Therefore, tissue engineering approaches aiming at the regeneration of bone tissue should be based on the use of materials possessing antibacterial properties alongside with biological and functional characteristics. In this study, we investigated the combination of polyhydroxyalkanoates (PHAs) with a novel antimicrobial hydroxyapatite (HA) containing selenium and strontium. Strontium was chosen for its well-known osteoinductive properties, while selenium is an emerging element investigated for its multi-functional activity as an antimicrobial and anticancer agent. Successful incorporation of such ions in the HA structure was obtained. Antibacterial activity against Staphylococcus aureus 6538P and Escherichia coli 8739 was confirmed for co-substituted HA in the powder form. Polymer-matrix composites based on two types of PHAs, P(3HB) and P(3HO-co-3HD-co-3HDD), were prepared by the incorporation of the developed antibacterial HA. An in-depth characterization of the composite materials was conducted to evaluate the effect of the filler on the physicochemical, thermal, and mechanical properties of the films. In vitro antibacterial testing showed that the composite samples induce a high reduction of the number of S. aureus 6538P and E. coli 8739 bacterial cells cultured on the surface of the materials. The films are also capable of releasing active ions which inhibited the growth of both Gram-positive and Gram-negative bacteria
Application and investigation of a bound for outcome reporting bias
BACKGROUND: Direct empirical evidence for the existence of outcome reporting bias is accumulating and this source of bias is recognised as a potential threat to the validity of meta-analysis of randomised clinical trials. METHODS: A method for calculating the maximum bias in a meta-analysis due to publication bias is adapted for the setting where within-study selective non-reporting of outcomes is suspected, and compared to the alternative approach of missing data imputation. The properties of both methods are investigated in realistic small sample situations. RESULTS: The results suggest that the adapted Copas and Jackson approach is the preferred method for reviewers to apply as an initial assessment of robustness to within-study selective non-reporting. CONCLUSION: The Copas and Jackson approach is a useful method for systematic reviewers to apply to assess robustness to outcome reporting bias
Spatial and topological organization of DNA chains induced by gene co-localization
Transcriptional activity has been shown to relate to the organization of
chromosomes in the eukaryotic nucleus and in the bacterial nucleoid. In
particular, highly transcribed genes, RNA polymerases and transcription factors
gather into discrete spatial foci called transcription factories. However, the
mechanisms underlying the formation of these foci and the resulting topological
order of the chromosome remain to be elucidated. Here we consider a
thermodynamic framework based on a worm-like chain model of chromosomes where
sparse designated sites along the DNA are able to interact whenever they are
spatially close-by. This is motivated by recurrent evidence that there exists
physical interactions between genes that operate together. Three important
results come out of this simple framework. First, the resulting formation of
transcription foci can be viewed as a micro-phase separation of the interacting
sites from the rest of the DNA. In this respect, a thermodynamic analysis
suggests transcription factors to be appropriate candidates for mediating the
physical interactions between genes. Next, numerical simulations of the polymer
reveal a rich variety of phases that are associated with different topological
orderings, each providing a way to increase the local concentrations of the
interacting sites. Finally, the numerical results show that both
one-dimensional clustering and periodic location of the binding sites along the
DNA, which have been observed in several organisms, make the spatial
co-localization of multiple families of genes particularly efficient.Comment: Figures and Supplementary Material freely available on
http://dx.doi.org/10.1371/journal.pcbi.100067
Selective Affimers Recognise the BCLâ2 Family Proteins BCLâxL and MCLâ1âthrough Noncanonical Structural Motifs
The BCLâ2 family is a challenging group of proteins to target selectively due to sequence and structural homologies across the family. Selective ligands for the BCLâ2 family regulators of apoptosis are useful as probes to understand cell biology and apoptotic signalling pathways, and as starting points for inhibitor design. We have used phage display to isolate Affimer reagents (nonâantibodyâbinding proteins based on a conserved scaffold) to identify ligands for MCLâ1, BCLâxL, BCLâ2, BAK and BAX, then used multiple biophysical characterisation methods to probe the interactions. We established that purified Affimers elicit selective recognition of their target BCLâ2 protein. For antiâapoptotic targets BCLâxL and MCLâ1, competitive inhibition of their canonical proteinâprotein interactions is demonstrated. Coâcrystal structures reveal an unprecedented mode of molecular recognition; where a BH3 helix is normally bound, flexible loops from the Affimer dock into the BH3 binding cleft. Moreover, the Affimers induce a change in the target proteins towards a desirable drugâboundâlike conformation. These proofâofâconcept studies indicate that Affimers could be used as alternative templates to inspire the design of selective BCLâ2 family modulators and more generally other proteinâprotein interaction inhibitors
Assessing the psychometric and ecometric properties of neighborhood scales using adolescent survey data from urban and rural Scotland
This work was supported by NHS Health Scotland and the University of St Andrews.Background:Â Despite the well-established need for specific measurement instruments to examine the relationship between neighborhood conditions and adolescent well-being outcomes, few studies have developed scales to measure features of the neighborhoods in which adolescents reside. Moreover, measures of neighborhood features may be operationalised differently by adolescents living in different levels of urban/rurality. This has not been addressed in previous studies. The objectives of this study were to: 1) establish instruments to measure adolescent neighborhood features at both the individual and neighborhood level, 2) assess their psychometric and ecometric properties, 3) test for invariance by urban/rurality, and 4) generate neighborhood level scores for use in further analysis. Methods:Â Data were from the Scottish 2010 Health Behaviour in School-aged Children Survey, which included an over-sample of rural adolescents. The survey responses of interest came from questions designed to capture different facets of the local area in which each respondent resided. Intermediate data zones were used as proxies for neighborhoods. Internal consistency was evaluated by Cronbachâs alpha. Invariance was examined using confirmatory factor analysis. Multilevel models were used to estimate ecometric properties and generate neighborhood scores. Results:Â Two constructs labeled neighborhood social cohesion and neighborhood disorder were identified. Adjustment was made to the originally specified model to improve model fit and measures of invariance. At the individual level, reliability was .760 for social cohesion and .765 for disorder, and between .524 and .571 for both constructs at the neighborhood level. Individuals in rural areas experienced greater neighborhood social cohesion and lower levels of neighborhood disorder compared with those in urban areas. Conclusions:Â The scales are appropriate for measuring neighborhood characteristics experienced by adolescents across urban and rural Scotland, and can be used in future studies of neighborhoods and health. However, trade-offs between neighborhood sample size and reliability must be considered.Publisher PDFPeer reviewe
Osmoregulators proline and glycine betaine counteract salinity stress in canola
Salt inundation leads to increased salinization of arable land in many arid and semi-arid regions. Until genetic solutions are found farmers and growers must either abandon salt-affected fields or use agronomic treatments that alleviate salt stress symptoms. Here, field experiments were carried out to study the effect of the osmoregulators proline at 200 mg L-1 and glycine betaine at 400 mg L-1 in counteracting the harmful effect of soil salinity stress on canola plants grown in Egypt. We assessed growth characteristics, yield and biochemical constituents. Results show first that all growth characters decreased with increasing salinity stress but applied osmoregulators alleviated these negative effects. Second, salinity stress decreased photosynthetic pigments, K and P contents, whilst increasing proline, soluble sugars, ascorbic acid, Na and Cl contents. Third, application of osmoregulators without salt stress increased photosynthetic pigments, proline, soluble sugars, N, K and P contents whilst decreasing Na and Cl contents. It is concluded that the exogenously applied osmoregulators glycine betaine and proline can fully or partially counteract the harmful effect of salinity stress on growth and yield of canola.© INRA and Springer-Verlag, France 2012
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