348 research outputs found
Stability of bubbles in wax-based oleofoams: decoupling the effects of bulk oleogel rheology and interfacial rheology
Oleofoams are dispersions of gas bubbles in a continuous oil phase and can be stabilized by crystals of fatty acids or waxes adsorbing at the oil-air interface. Because excess crystals in the continuous phase form an oleogel, an effect of the bulk rheology of the continuous phase is also expected. Here, we evaluate the contributions of bulk and interfacial rheology below and above the melting point of a wax forming an oleogel in sunflower oil. We study the dissolution behaviour of single bubbles using microscopy on a temperature-controlled stage. We compare the behaviour of a bubble embedded in an oleofoam, which owes its stability to both bulk and interfacial rheology, to that of a bubble extracted from the oleofoam and resuspended in oil, for which the interfacial dilatational rheology alone provides stability. We find that below the melting point of the wax, bubbles in the oleofoam are stable whereas bubbles that are only coated with wax crystals dissolve. Both systems dissolve when heated above the melting point of the wax. These findings are rationalized through independent bulk rheological measurements of the oleogel at different temperatures, as well as measurements of the dilatational rheological properties of a wax-coated oil-air interface
Stability of bubbles in wax-based oleofoams: decoupling the effects of bulk oleogel rheology and interfacial rheology
Oleofoams are dispersions of gas bubbles in a continuous oil phase and can be stabilized by crystals of fatty acids or waxes adsorbing at the oil-air interface. Because excess crystals in the continuous phase form an oleogel, an effect of the bulk rheology of the continuous phase is also expected. Here, we evaluate the contributions of bulk and interfacial rheology below and above the melting point of a wax forming an oleogel in sunflower oil. We study the dissolution behaviour of single bubbles using microscopy on a temperature-controlled stage. We compare the behaviour of a bubble embedded in an oleofoam, which owes its stability to both bulk and interfacial rheology, to that of a bubble extracted from the oleofoam and resuspended in oil, for which the interfacial dilatational rheology alone provides stability. We find that below the melting point of the wax, bubbles in the oleofoam are stable whereas bubbles that are only coated with wax crystals dissolve. Both systems dissolve when heated above the melting point of the wax. These findings are rationalized through independent bulk rheological measurements of the oleogel at different temperatures, as well as measurements of the dilatational rheological properties of a wax-coated oil-air interface
Probing quantum and classical turbulence analogy through global bifurcations in a von K\'arm\'an liquid Helium experiment
We report measurements of the dissipation in the Superfluid Helium high
REynold number von Karman flow (SHREK) experiment for different forcing
conditions, through a regime of global hysteretic bifurcation. Our
macroscopical measurements indicate no noticeable difference between the
classical fluid and the superfluid regimes, thereby providing evidence of the
same dissipative anomaly and response to asymmetry in fluid and superfluid
regime. %In the latter case, A detailed study of the variations of the
hysteretic cycle with Reynolds number supports the idea that (i) the stability
of the bifurcated states of classical turbulence in this closed flow is partly
governed by the dissipative scales and (ii) the normal and the superfluid
component at these temperatures (1.6K) are locked down to the dissipative
length scale.Comment: 5 pages, 5 figure
Performance Scores in General Practice: A Comparison between the Clinical versus Medication-Based Approach to Identify Target Populations
CONTEXT: From one country to another, the pay-for-performance mechanisms differ on one significant point: the identification of target populations, that is, populations which serve as a basis for calculating the indicators. The aim of this study was to compare clinical versus medication-based identification of populations of patients with diabetes and hypertension over the age of 50 (for men) or 60 (for women), and any consequences this may have on the calculation of P4P indicators. METHODS: A comparative, retrospective, observational study was carried out with clinical and prescription data from a panel of general practitioners (GPs), the Observatory of General Medicine (OMG) for the year 2007. Two indicators regarding the prescription for statins and aspirin in these populations were calculated. RESULTS: We analyzed data from 21.690 patients collected by 61 GPs via electronic medical files. Following the clinical-based approach, 2.278 patients were diabetic, 8,271 had hypertension and 1.539 had both against respectively 1.730, 8.511 and 1.304 following the medication-based approach (% agreement = 96%, kappa = 0.69). The main reasons for these differences were: forgetting to code the morbidities in the clinical approach, not taking into account the population of patients who were given life style and diet rules only or taking into account patients for whom morbidities other than hypertension could justify the use of antihypertensive drugs in the medication-based approach. The mean (confidence interval) per doctor was 33.7% (31.5-35.9) for statin indicator and 38.4% (35.4-41.4) for aspirin indicator when the target populations were identified on the basis of clinical criteria whereas they were 37.9% (36.3-39.4) and 43.8% (41.4-46.3) on the basis of treatment criteria. CONCLUSION: The two approaches yield very "similar" scores but these scores cover different realities and offer food for thought on the possible usage of these indicators in the framework of P4P programmes
Immune-Mediated Change in the Expression of a Sexual Trait Predicts Offspring Survival in the Wild
BACKGROUND: The "good genes" theory of sexual selection postulates that females choose mates that will improve their offspring's fitness through the inheritance of paternal genes. In spite of the attention that this hypothesis has given rise to, the empirical evidence remains sparse, mostly because of the difficulties of controlling for the many environmental factors that may covary with both the paternal phenotype and offspring fitness. Here, we tested the hypothesis that offspring sired by males of a preferred phenotype should have better survival in an endangered bird, the houbara bustard (Chlamydotis undulata undulata). METHODOLOGY/PRINCIPAL FINDINGS: We tested if natural and experimentally-induced variation in courtship display (following an inflammatory challenge) predicts the survival of offspring. Chicks were produced by artificial insemination of females, ensuring that any effect on survival could only arise from the transfer of paternal genes. One hundred and twenty offspring were equipped with radio transmitters, and their survival monitored in the wild for a year. This allowed assessment of the potential benefits of paternal genes in a natural setting, where birds experience the whole range of environmental hazards. Although natural variation in sire courtship display did not predict offspring survival, sires that withstood the inflammatory insult and maintained their courtship activity sired offspring with the best survival upon release. CONCLUSIONS: This finding is relevant both to enlighten the debate on "good genes" sexual selection and the management of supportive breeding programs
Prediction of post-operative necrosis after mastectomy: A pilot study utilizing optical diffusion imaging spectroscopy
<p>Abstract</p> <p>Introduction</p> <p>Flap necrosis and epidermolysis occurs in 18-30% of all mastectomies. Complications may be prevented by intra-operative detection of ischemia. Currently, no technique enables quantitative valuation of mastectomy skin perfusion. Optical Diffusion Imaging Spectroscopy (ViOptix T.Ox Tissue Oximeter) measures the ratio of oxyhemoglobin to deoxyhemoglobin over a 1 × 1 cm area to obtain a non-invasive measurement of perfusion (StO<sub>2</sub>).</p> <p>Methods</p> <p>This study evaluates the ability of ViOptix T.Ox Tissue Oximeter to predict mastectomy flap necrosis. StO<sub>2 </sub>measurements were taken at five points before and at completion of dissection in 10 patients. Data collected included: demographics, tumor size, flap length/thickness, co-morbidities, procedure length, and wound complications.</p> <p>Results</p> <p>One patient experienced mastectomy skin flap necrosis. Five patients underwent immediate reconstruction, including the patient with necrosis. Statistically significant factors contributing to necrosis included reduction in medial flap StO<sub>2 </sub>(p = 0.0189), reduction in inferior flap StO<sub>2 </sub>(p = 0.003), and flap length (p = 0.009).</p> <p>Conclusion</p> <p>StO<sub>2 </sub>reductions may be utilized to identify impaired perfusion in mastectomy skin flaps.</p
Pediatric-onset Evans syndrome: Heterogeneous presentation and high frequency of monogenic disorders including LRBA and CTLA4 mutations
Evans syndrome (ES) is defined by the combination of autoimmune hemolytic anemia and immune thrombocytopenia. Clinical presentation includes manifestations of immune dysregulation, found in primary immune deficiencies, autoimmune lymphoproliferative syndrome with FAS (ALPS-FAS), Cytotoxic T Lymphocyte Antigen-4 (CTLA-4) and Lipopolysaccharide-Responsive vesicle trafficking Beige-like and Anchor protein (LRBA) defects. We report the clinical history and genetic results of 18 children with ES after excluding ALPS-FAS. Thirteen had organomegaly, five lymphocytic infiltration of non-lymphoid organs, nine hypogammaglobulinemia and fifteen anomalies in lymphocyte phenotyping. Seven patients had genetic defects: three CTLA4 mutations (c.151C>T; c.109+1092_568-512del; c.110-2A>G) identified by Sanger sequencing and four revealed by Next Generation Sequencing: LRBA (c.2450+1C>T), STAT3 gain-of-function (c.2147C>T; c.2144C>T) and KRAS (c.37G>T). No feature emerged to distinguish patients with or without genetic diagnosis. Our data on pediatric-onset ES should prompt physicians to perform extensive screening for mutations in the growing pool of genes involved in primary immune deficiencies with autoimmunity
Search for CP Violation in the Decay Z -> b (b bar) g
About three million hadronic decays of the Z collected by ALEPH in the years
1991-1994 are used to search for anomalous CP violation beyond the Standard
Model in the decay Z -> b \bar{b} g. The study is performed by analyzing
angular correlations between the two quarks and the gluon in three-jet events
and by measuring the differential two-jet rate. No signal of CP violation is
found. For the combinations of anomalous CP violating couplings, and , limits of \hat{h}_b < 0.59h^{\ast}_{b} < 3.02$ are given at 95\% CL.Comment: 8 pages, 1 postscript figure, uses here.sty, epsfig.st
A Nuclear Localization of the Infectious Haematopoietic Necrosis Virus NV Protein Is Necessary for Optimal Viral Growth
The nonvirion (NV) protein of infectious hematopoietic necrosis virus (IHNV) has been previously reported to be essential for efficient growth and pathogenicity of IHNV. However, little is known about the mechanism by which the NV supports the viral growth. In this study, cellular localization of NV and its role in IHNV growth in host cells was investigated. Through transient transfection in RTG-2 cells of NV fused to green fluorescent protein (GFP), a nuclear localization of NV was demonstrated. Deletion analyses showed that the 32EGDL35 residues were essential for nuclear localization of NV protein, and fusion of these 4 amino acids to GFP directed its transport to the nucleus. We generated a recombinant IHNV, rIHNV-NV-ΔEGDL in which the 32EGDL35 was deleted from the NV. rIHNVs with wild-type NV (rIHNV-NV) or with the NV gene replaced with GFP (rIHNV-ΔNV-GFP) were used as controls. RTG-2 cells infected with rIHNV-ΔNV-GFP and rIHNV-NV-ΔEGDL yielded 12- and 5-fold less infectious virion, respectively, than wild type rIHNV-infected cells at 48 h post-infection (p.i.). While treatment with poly I∶C at 24 h p.i. did not inhibit replication of wild-type rIHNVs, replication rates of rIHNV-ΔNV-GFP and rIHNV-NV-ΔEGDL were inhibited by poly I∶C. In addition, both rIHNV-ΔNV and rIHNV-NV-ΔEGDL induced higher levels of expressions of both IFN1 and Mx1 than wild-type rIHNV. These data suggest that the IHNV NV may support the growth of IHNV through inhibition of the INF system and the amino acid residues of 32EGDL35 responsible for nuclear localization are important for the inhibitory activity of NV
Association of socioeconomic status with overall overweight and central obesity in men and women: the French Nutrition and Health Survey 2006
<p>Abstract</p> <p>Background</p> <p>Identification of subpopulations at high risk of overweight and obesity is crucial for prevention and management of obesity in different socioeconomic status (SES) categories. The objective of the study was to describe disparities in the prevalence of overweight and obesity across socioeconomic status (SES) groups in 18–74 year-old French adults.</p> <p>Methods</p> <p>Analyses were based on a multistage stratified random sample of non-institutionalized adults aged 18–74-years-old from the French Nutrition and Health Survey (ENNS), a cross-sectional national survey carried out in 2006/2007. Collected data included measured anthropometry (weight, height and waist circumference (WC)), demographic and SES data (occupation, education and frequency of holiday trips as a marker of family income). SES factors associated with overweight (BMI ≥ 25) and central obesity (WC above gender-specific references) were identified using multiple logistic regression.</p> <p>Results</p> <p>Almost half (49.3%) of French adults were overweight or obese and 16.9% were obese. In men, the risk of overall overweight or obesity was associated with occupation (p < 0.05), whereas the risk of central obesity was independently associated with occupation (p < 0.05) and frequency of holiday trips (p < 0.01). In women, both overall and central overweight and obesity were independently associated with educational level (respectively p < 10<sup>-3 </sup>and p < 10<sup>-3</sup>) and frequency of holiday trips (respectively p < 0.05 and p < 10<sup>-3</sup>).</p> <p>Conclusion</p> <p>The prevalence of overweight and obesity was found to be similar to that of several neighbouring western European countries, and lower than the UK and eastern Europe. Risk of being overweight or obese varied across SES groups both in men and women, but associations were different between men and women, indicating differing determinants.</p
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