434 research outputs found
Measuring patient-reported outcomes: moving beyond misplaced common sense to hard science
Interest in the patient's views of his or her illness and treatment has increased dramatically. However, our ability to appropriately measure such issues lags far behind the level of interest and need. Too often such measurement is considered to be a simple and trivial activity that merely requires the application of common sense. However, good quality measurement of patient-reported outcomes is a complex activity requiring considerable expertise and experience. This review considers the most important issues related to such measurement in the context of chronic disease and details how instruments should be developed, validated and adapted for use in additional languages. While there is often consensus on how best to undertake these activities, there is generally little evidence to support such accord. The present article questions these orthodox views and suggests alternative approaches that have been shown to be effective
Using liminality to understand mothers’ experiences of long-term breastfeeding: ‘Betwixt and between’, and ‘matter out of place’
© 2015, © The Author(s) 2015. Breastmilk is widely considered as the optimum nutrition source for babies and an important factor in both improving public health and reducing health inequalities. Current international/national policy supports long-term breastfeeding. UK breastfeeding initiation rates are high but rapidly decline, and the numbers breastfeeding in the second year and beyond are unknown. This study used the concept of liminality to explore the experiences of a group of women breastfeeding long-term in the United Kingdom, building on Mahon-Daly and Andrews. Over 80 breastfeeding women were included within the study, which used micro-ethnographic methods (participant observation in breastfeeding support groups, face-to-face interviews and online asynchronous interviews via email). Findings about women’s experiences are congruent with the existing literature, although it is mostly dated and from outside the United Kingdom. Liminality was found to be useful in providing insight into women’s experiences of long-term breastfeeding in relation to both time and place. Understanding women’s experience of breastfeeding beyond current usual norms can be used to inform work with breastfeeding mothers and to encourage more women to breastfeed for longer
Green Fluorescent Protein Labeling of Listeria, Salmonella, and Escherichia coli O157:H7 for Safety-Related Studies
Many food safety-related studies require tracking of introduced foodborne pathogens to monitor their fate in complex environments. The green fluorescent protein (GFP) gene (gfp) provides an easily detectable phenotype so has been used to label many microorganisms for ecological studies. The objectives of this study were to label major foodborne pathogens and related bacteria, including Listeria monocytogenes, Listeria innocua, Salmonella, and Escherichia coli O157:H7 strains, with GFP and characterize the labeled strains for stability of the GFP plasmid and the plasmid's effect on bacterial growth. GFP plasmids were introduced into these strains by a CaCl2 procedure, conjugation or electroporation. Stability of the label was determined through sequential propagation of labeled strains in the absence of selective pressure, and rates of plasmid-loss were calculated. Stability of the GFP plasmid varied among the labeled species and strains, with the most stable GFP label observed in E. coli O157:H7. When grown in nonselective media for two consecutive subcultures (ca. 20 generations), the rates of plasmid loss among labeled E. coli O157:H7, Salmonella and Listeria strains ranged from 0%–30%, 15.8%–99.9% and 8.1%–93.4%, respectively. Complete loss (>99.99%) of the plasmid occurred in some labeled strains after five consecutive subcultures in the absence of selective pressure, whereas it remained stable in others. The GFP plasmid had an insignificant effect on growth of most labeled strains. E. coli O157:H7, Salmonella and Listeria strains can be effectively labeled with the GFP plasmid which can be stable in some isolates for many generations without adversely affecting growth rates
Mosquito Infection Responses to Developing Filarial Worms
Human lymphatic filariasis is a mosquito-vectored disease caused by the nematode parasites Wuchereria bancrofti, Brugia malayi and Brugia timori. These are relatively large roundworms that can cause considerable damage in compatible mosquito vectors. In order to assess how mosquitoes respond to infection in compatible mosquito-filarial worm associations, microarray analysis was used to evaluate transcriptome changes in Aedes aegypti at various times during B. malayi development. Changes in transcript abundance in response to the different stages of B. malayi infection were diverse. At the early stages of midgut and thoracic muscle cell penetration, a greater number of genes were repressed compared to those that were induced (20 vs. 8). The non-feeding, intracellular first-stage larvae elicited few differences, with 4 transcripts showing an increased and 9 a decreased abundance relative to controls. Several cecropin transcripts increased in abundance after parasites molted to second-stage larvae. However, the greatest number of transcripts changed in abundance after larvae molted to third-stage larvae and migrated to the head and proboscis (120 induced, 38 repressed), including a large number of putative, immunity-related genes (∼13% of genes with predicted functions). To test whether the innate immune system of mosquitoes was capable of modulating permissiveness to the parasite, we activated the Toll and Imd pathway controlled rel family transcription factors Rel1 and Rel2 (by RNA interference knockdown of the pathway's negative regulators Cactus and Caspar) during the early stages of infection with B. malayi. The activation of either of these immune signaling pathways, or knockdown of the Toll pathway, did not affect B. malayi in Ae. aegypti. The possibility of LF parasites evading mosquito immune responses during successful development is discussed
A space–time Trefftz discontinuous Galerkin method for the acoustic wave equation in first-order formulation
We introduce a space–time Trefftz discontinuous Galerkin method for the first-order transient acoustic wave equations in arbitrary space dimensions, extending the one-dimensional scheme of Kretzschmar et al. (IMA J Numer Anal 36:1599–1635, 2016). Test and trial discrete functions are space–time piecewise polynomial solutions of the wave equations. We prove well-posedness and a priori error bounds in both skeleton-based and mesh-independent norms. The space–time formulation corresponds to an implicit time-stepping scheme, if posed on meshes partitioned in time slabs, or to an explicit scheme, if posed on “tent-pitched” meshes. We describe two Trefftz polynomial discrete spaces, introduce bases for them and prove optimal, high-order h-convergence bounds
Sliding Wear Behavior of Al2O3-TiO2 Coatings Fabricated by the Suspension Plasma Spraying Technique
[EN] The friction and dry sliding wear behavior of alumina and alumina-titania near-nanometric coatings were examined. Coatings were obtained by the suspension plasma spraying technique. Dry sliding wear tests were performed on a ball-on-disk tribometer, with an Al2O3 ball as counterpart material, a normal load of 2 N, a sliding distance of 1200 m and a sliding speed of 0.1 m/s. The effect of including TiO2 in the fabricated coatings on friction coefficient behavior, wear rates and wear damage patterns was determined. The addition of TiO2 to the coatings was found to greatly increase wear resistance by, for example, 2.6-fold for 40 wt% of TiO2. The analysis of the wear surface was correlated with microstructural parameters, mechanical properties and wear rates.The authors wish to thank for the Spanish Ministry of Economy and Competitiveness (MAT2012-38364-C03) and the Autonomous Government of Valencia for funding for the stay in SPCTS-UMR CNRS (France), and the French FCENANOSURF consortium funded by the French Ministry and Industry and local governments of Region Centre and Region Limousin.Klyatskina, E.; Espinosa Fernández, L.; Darut, G.; Segovia López, EF.; Salvador Moya, MD.; Montavon, G.; Agorges, H. (2015). Sliding Wear Behavior of Al2O3-TiO2 Coatings Fabricated by the Suspension Plasma Spraying Technique. Tribology Letters. 59(1):1-9. https://doi.org/10.1007/s11249-015-0530-5S19591Pawlowski, L.: The Science and Engineering of Thermal Spray Coatings. Wiley: Hoboken (2008)Lampe, Th, Eisenberg, S., Cabeo, E.R.: Plasma surface engineering in the automotive industry—trends and future prospective. Surf. Coat. Technol. 174–175, 1–7 (2003)Wang, Y., Jiang, S., Wang, M., Wang, S., Xiao, T.D., Strutt, P.R.: Abrasive wear characteristics of plasma sprayed nanostructured alumina/titania coatings. Wear 237, 176–185 (2000)Kabacoff, L.T.: Nanoceramic coatings exhibit much higher toughness and wear resistance than conventional coatings. AMPITAC Newslett. 6(1), 37–42 (2002)Wang, M., Shaw, L.L.: Effects of the powder manufacturing method on microstructure and wear performance of plasma sprayed alumina–titania coatings. Surf. Coat. Technol. 202, 34–44 (2007)Shaw, L.L., Goberman, D., Ren, R., Gell, M., Jing, S., Wang, Y., Xiao, T.D., Strutt, P.R.: The dependency of microstructure and properties of nanostructured coatings on plasma spray conditions. Surf. Coat. Technol. 130, 1–8 (2000)Dahotre, N.B., Nayak, S.: Nanocoatings for engine application. Surf. Coat. Technol. 194(1), 58–67 (2005)Sathish, S., Geetha, M., Aruna, S.T., Balaji, N., Rajam, K.S., Asokamani, R.: Sliding wear behavior of plasma sprayed nanoceramic coatings for biomedical applications. Wear 271, 934–941 (2011)Pawlowski, L.: Finely grained nanometric and submicrometric coatings by thermal sparing: a review. Surf. Coat. Technol. 202, 4318–4328 (2008)Xiao, D., Wang, Y., Strutt, P.: Fabrication and evaluation of plasma sprayed nanostructured alumina–titania coatings with superior properties. Mater. Sci. Eng. 301, 80–89 (2001)Tjong, S.C., Chen, H.: Nanocrystalline materials and coatings. Mater. Sci. Eng. 45, 1–88 (2004)Fauchais, P., Montavon, G., Bertrand, G.: From powders to thermally sprayed coatings. J. Therm. Spray Technol. 19, 56–80 (2010)Lima, R.S., Marple, B.R.: Thermal spray coatings engineered from nanostructured ceramic agglomerated powders for structural, thermal barrier and biomedical applications: a review. J. Therm. Spray Technol. 16, 40–63 (2007)Fauchais, P., Etchart-Salas, R., Delbos, C., Tognonvi, M., Rat, V., Coudert, J.F., Chartier, T.: Suspension and solution plasma spraying of finely structured layers: potential application to SOFCs. J. Phys. D Appl. Phys. 40, 2394–2406 (2007)Ramachandran, K., Selvajaran, V., Ananthapadmanabhan, P.V., Sreekumar, K.P.: Microstructure, adhesion, micro hardness, abrasive wear resistance and electrical resistivity of the plasma sprayed alumina and alumina–titania coatings. Thin Solid Films 315, 144–152 (1998)Lee, S.W., Morillo, C., Lira-Olivares, J., Kim, S.H., Sekino, T., Niihara, K., Hockey, B.J.: Tribological and microstructural analysis of Al2O3/13TiO2 nanocomposites to use in femoral head of hip replacement. Wear 225, 1040–1044 (2003)Dejang, N., Watcharapasorn, A., Wirojupatump, S., Niranatlumpong, P., Jiansirisomboon, S.: Fabrication and properties of plasma-sprayed Al2O3/TiO2 composite coatings: a role of nano-sized TiO2 addition. Surf. Coat. Technol. 204, 1651–1657 (2010)Yimaz, S.: An evaluation of plasma sprayed coatings based on Al2O3 and Al2O3–13wt% TiO2 with bond coat on pure titanium substrate. Ceram. Int. 35, 2017–2022 (2009)Fervel, V., Normand, B., Coddet, C.: Tribological behavior of plasma sprayed Al2O3-based cermet coatings. Wear 230(1), 70–77 (1999)Vargas, F., Ageorges, H., Fauchais, P., López, M.E.: Mechanical and a tribological performance of Al2O3 coatings elaborated by flame and plasma spraying. Surf. Coat. Technol. 205, 1132–1136 (2010)Bacciochini, A., Ilavsky, J., Montavon, G., Denoirjean, A., Ben-ettouil, F., Valette, S., Fauchais, P., Wittmann-teneze, K.: Quantification of void network architectures of suspension plasma-sprayed (SPS) yttria-stabilized zirconia (YSZ) coatings using ultra-small-angle X-ray scattering (USAXS). Mater. Sci. Eng. 528, 91–102 (2010)ASTM International: ASTM G99-03: Standard test method for wear testing with a pin-on-disc apparatus. ASTM annual book of standards. ASTM International: West Conshohocken (2003)Lancaster, K.: The influence of substrate hardness on the formation and endurance of molybdenum disulphide films. Wear 10, 103–107 (1967)Fauchais, P., Rat, V., Delbos, C., Fazilleau, J., Coudert, J.F., Chartier, T., Bianchi, L.: Understanding of suspension plasma spraying of finely structured coatings for SOFC. IEEE Plasma Sci. 33(2), 920–930 (2005)Bannier, E., Vicent, M., Rayón, E., Benavente, R., Salvador, M.D., Sánchez, E.: Effect of TiO2 addition on the microstructure and nanomechanical properties of Al2O3 suspension plasma sprayed coatings. Appl. Surf. Sci. 316, 141–146 (2014)Darut, G., Klyatskina, E., Valette, S., Carles, P., Denoirjean, A., Montavon, G., Ageorges, H., Segovia, F., Salvador, M.D.: Architecture and phases composition of suspension plasma sprayed alumina–titania sub-micrometer-sized coatings. Mater. 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Over-expression of lysophosphatidic acid receptor-2 in human invasive ductal carcinoma
INTRODUCTION: Lysophosphatidic acid (LPA) is a bioactive phospholipid with diverse effects on various cells. It interacts with at least three G-protein-coupled transmembrane receptors, namely LPA1, LPA2 and LPA3, whose expression in various tumours has not been fully characterized. In the present study we characterized the expression profile of LPA receptors in human breast cancer tissue and assessed the possible roles of each receptor. METHODS: The relative expression levels of each receptor's mRNA against β-actin mRNA was examined in surgically resected invasive ductal carcinomas and normal gland tissue using real-time RT-PCR. LPA2 expression was also examined immunohistochemically using a rat anti-LPA2 monoclonal antibody. RESULTS: In 25 cases normal and cancer tissue contained LPA1 mRNA at similar levels, whereas the expression level of LPA2 mRNA was significantly increased in cancer tissue as compared with its normal counterpart (3479.0 ± 426.6 versus 1287.3 ± 466.8; P < 0.05). LPA3 was weakly expressed in both cancer and normal gland tissue. In 48 (57%) out of 84 cases, enhanced expression of LPA2 protein was confirmed in carcinoma cells as compared with normal mammary epithelium by immunohistochemistry. Over-expression of LPA2 was detected in 17 (45%) out of 38 premenopausal women, as compared with 31 (67%) out of 46 postmenopausal women, and the difference was statistically significant (P < 0.05). CONCLUSION: These findings suggest that upregulation of LPA2 may play a role in carcinogenesis, particularly in postmenopausal breast cancer
The neural processing of taste
Although there have been many recent advances in the field of gustatory neurobiology, our knowledge of how the nervous system is organized to process information about taste is still far from complete. Many studies on this topic have focused on understanding how gustatory neural circuits are spatially organized to represent information about taste quality (e.g., "sweet", "salty", "bitter", etc.). Arguments pertaining to this issue have largely centered on whether taste is carried by dedicated neural channels or a pattern of activity across a neural population. But there is now mounting evidence that the timing of neural events may also importantly contribute to the representation of taste. In this review, we attempt to summarize recent findings in the field that pertain to these issues. Both space and time are variables likely related to the mechanism of the gustatory neural code: information about taste appears to reside in spatial and temporal patterns of activation in gustatory neurons. What is more, the organization of the taste network in the brain would suggest that the parameters of space and time extend to the neural processing of gustatory information on a much grander scale
RNA-seq analyses of blood-induced changes in gene expression in the mosquito vector species, Aedes aegypti
<p>Abstract</p> <p>Background</p> <p>Hematophagy is a common trait of insect vectors of disease. Extensive genome-wide transcriptional changes occur in mosquitoes after blood meals, and these are related to digestive and reproductive processes, among others. Studies of these changes are expected to reveal molecular targets for novel vector control and pathogen transmission-blocking strategies. The mosquito <it>Aedes aegypti </it>(Diptera, Culicidae), a vector of Dengue viruses, Yellow Fever Virus (YFV) and Chikungunya virus (CV), is the subject of this study to look at genome-wide changes in gene expression following a blood meal.</p> <p>Results</p> <p>Transcriptional changes that follow a blood meal in <it>Ae. aegypti </it>females were explored using RNA-seq technology. Over 30% of more than 18,000 investigated transcripts accumulate differentially in mosquitoes at five hours after a blood meal when compared to those fed only on sugar. Forty transcripts accumulate only in blood-fed mosquitoes. The list of regulated transcripts correlates with an enhancement of digestive activity and a suppression of environmental stimuli perception and innate immunity. The alignment of more than 65 million high-quality short reads to the <it>Ae. aegypti </it>reference genome permitted the refinement of the current annotation of transcript boundaries, as well as the discovery of novel transcripts, exons and splicing variants. <it>Cis</it>-regulatory elements (CRE) and <it>cis</it>-regulatory modules (CRM) enriched significantly at the 5'end flanking sequences of blood meal-regulated genes were identified.</p> <p>Conclusions</p> <p>This study provides the first global view of the changes in transcript accumulation elicited by a blood meal in <it>Ae. aegypti </it>females. This information permitted the identification of classes of potentially co-regulated genes and a description of biochemical and physiological events that occur immediately after blood feeding. The data presented here serve as a basis for novel vector control and pathogen transmission-blocking strategies including those in which the vectors are modified genetically to express anti-pathogen effector molecules.</p
Cognitive Reserve and the Prevention of Dementia: the Role of Physical and Cognitive Activities
Purpose of Review: The article discusses the two most significant modifiable risk factors for dementia, namely, physical inactivity and lack of stimulating cognitive activity, and their effects on developing cognitive reserve. Recent Findings: Both of these leisure-time activities were associated with significant reductions in the risk of dementia in longitudinal studies. In addition, physical activity, particularly aerobic exercise, is associated with less age-related gray and white matter loss and with less neurotoxic factors. On the other hand, cognitive training studies suggest that training for executive functions (e.g., working memory) improves prefrontal network efficiency, which provides support to brain functioning in the face of cognitive decline. Summary: While physical activity preserves neuronal structural integrity and brain volume (hardware), cognitive activity strengthens the functioning and plasticity of neural circuits (software), thus supporting cognitive reserve in different ways. Future research should examine whether lifestyle interventions incorporating these two domains can reduce incident dementia
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