302 research outputs found

    Weak and saturable protein-surfactant interactions in the denaturation of apo-α-lactalbumin by acidic and lactonic sophorolipid

    Get PDF
    Biosurfactants are of growing interest as sustainable alternatives to fossil-fuel-derived chemical surfactants, particularly for the detergent industry. To realize this potential, it is necessary to understand how they affect proteins which they may encounter in their applications. However, knowledge of such interactions is limited. Here, we present a study of the interactions between the model protein apo-alpha-lactalbumin (apo-aLA) and the biosurfactant sophorolipid (SL) produced by the yeast Starmerella bombicola. SL occurs both as an acidic and a lactonic form; the lactonic form (lactSL) is sparingly soluble and has a lower critical micelle concentration (cmc) than the acidic form [non-acetylated acidic sophorolipid (acidSL)]. We show that acidSL affects apo-aLA in a similar way to the related glycolipid biosurfactant rhamnolipid (RL), with the important difference that RL is also active below the cmc in contrast to acidSL. Using isothermal titration calorimetry data, we show that acidSL has weak and saturable interactions with apo-aLA at low concentrations; due to the relatively low cmc of acidSL (which means that the monomer concentration is limited to ca. 0-1 mM SL), it is only possible to observe interactions with monomeric acidSL at high apo-aLA concentrations. However, the denaturation kinetics of apo-aLA in the presence of acidSL are consistent with a collaboration between monomeric and micellar surfactant species, similar to RL and non-ionic or zwitterionic surfactants. Inclusion of diacetylated lactonic sophorolipid (lactSL) as mixed micelles with acidSL lowers the cmc and this effectively reduces the rate of unfolding, emphasizing that SL like other biosurfactants is a gentle anionic surfactant. Our data highlight the potential of these biosurfactants for future use in the detergent and pharmaceutical industry

    Perceived barriers in family-based behavioural treatment of paediatric obesity – Results from the FABO study

    Get PDF
    This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.Background: To date, few studies have investigated perceived barriers among those who participate in and drop out of family-based behavioural treatment (FBT) for paediatric obesity. Examining experienced barriers during treatment, and their role in participation and completion of treatment has important implications for clinical practice. Objectives: To compare perceived barriers to participating in a family-based behavioural social facilitation treatment (FBSFT) for obesity among families who completed and did not complete treatment. Methods: Data were analysed from 90 families of children and adolescents (mean (M) age = 12.8 years, standard deviation (SD) = 3.05) with severe obesity enrolled in a 17-session FBSFT program. After completing 12 sessions or at the time of dropout, parents and therapists completed the Barriers to Treatment Participation Scale (BTPS), a 5-point Likert scale (1 = never a problem, 5 = very often a problem) which includes four subscales: 1. Stressors and obstacles that compete with treatment, 2. Treatment demands and issues, 3. Perceived relevance of treatment, 4. Relationship with the therapist. Results: Families who did not complete treatment scored significantly higher on the BTPS subscales stressors and obstacles that compete with treatment (M = 2.03, SD = 0.53 vs. M = 1.70, SD = 0.42), p = 0.010 and perceived relevance of treatment (M = 2.27, SD = 0.48 vs. M = 1.80, SD = 0.50), p < 0.001 than families who completed treatment. No other significant differences between groups were observed. Conclusion: Families are more likely to drop out of FBSFT when experiencing a high burden from life stressors or when treatment is not meeting the expectations and perceived needs of the family.publishedVersio

    Family-based treatment of children with severe obesity in a public healthcare setting: Results from a randomized controlled trial

    Get PDF
    To compare the effectiveness of family-based behavioural social facilitation treatment (FBSFT) versus treatment as usual (TAU) in children with severe obesity. Parallel-design, nonblinded, randomized controlled trial conducted at a Norwegian obesity outpatient clinic. Children aged 6–18 years referred to the clinic between 2014 and 2018 were invited to participate. Participants were randomly allocated using sequentially numbered, opaqued, sealed envelopes. FBSFT (n = 59) entailed 17 sessions of structured cognitive behavioural treatment, TAU (n = 55) entailed standard lifestyle counselling sessions every third month for 1 year. Primary outcomes included changes in body mass index standard deviation score (BMI SDS) and percentage above the International Obesity Task Force cut-off for overweight (%IOTF-25). Secondary outcomes included changes in sleep, physical activity, and eating behaviour. From pre- to posttreatment there was a statistically significant difference in change in both BMI SDS (0.19 units, 95% confidence interval [CI]: 0.10–0.28, p < .001) and %IOTF-25 (5.48%, 95%CI: 2.74–8.22, p < .001) between FBSFT and TAU groups. FBSFT participants achieved significant reductions in mean BMI SDS (0.16 units, (95%CI: −0.22 to −0.10, p < .001) and %IOTF-25 (6.53%, 95% CI: −8.45 to −4.60, p < .001), whereas in TAU nonsignificant changes were observed in BMI SDS (0.03 units, 95% CI: −0.03 to 0.09, p = .30) and %IOTF-25 (−1.04%, 95% CI: −2.99 to −0.90, p = .29). More FBSFT participants (31.5%) had clinically meaningful BMI SDS reductions of ≥0.25 from pre- to posttreatment than in TAU (13.0%, p = .021). Regarding secondary outcomes, only changes in sleep timing differed significantly between groups. FBSFT improved weight-related outcomes compared to TAU.publishedVersio

    Evidence for directional selection at a novel major histocompatibility class I marker in wild common frogs (Rana temporaria) exposed to a viral pathogen (Ranavirus).

    Get PDF
    (c) 2009 Teacher et al. This 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.Whilst the Major Histocompatibility Complex (MHC) is well characterized in the anuran Xenopus, this region has not previously been studied in another popular model species, the common frog (Rana temporaria). Nor, to date, have there been any studies of MHC in wild amphibian host-pathogen systems. We characterise an MHC class I locus in the common frog, and present primers to amplify both the whole region, and specifically the antigen binding region. As no more than two expressed haplotypes were found in over 400 clones from 66 individuals, it is likely that there is a single class I locus in this species. This finding is consistent with the single class I locus in Xenopus, but contrasts with the multiple loci identified in axolotls, providing evidence that the diversification of MHC class I into multiple loci likely occurred after the Caudata/Anura divergence (approximately 350 million years ago) but before the Ranidae/Pipidae divergence (approximately 230 mya). We use this locus to compare wild populations of common frogs that have been infected with a viral pathogen (Ranavirus) with those that have no history of infection. We demonstrate that certain MHC supertypes are associated with infection status (even after accounting for shared ancestry), and that the diseased populations have more similar supertype frequencies (lower F(ST)) than the uninfected. These patterns were not seen in a suite of putatively neutral microsatellite loci. We interpret this pattern at the MHC locus to indicate that the disease has imposed selection for particular haplotypes, and hence that common frogs may be adapting to the presence of Ranavirus, which currently kills tens of thousands of amphibians in the UK each year

    Теоретико-методологічні основи розуміння механізму правового регулювання

    Get PDF
    Метою цієї статті є аналіз напрямів наукових досліджень, що у своїй єдності формують теорію механізму правового регулювання (МПР), розкриття теоретикометодологічних проблем, які мають місце при осмисленні МПР, визначення та систематизація методологічних підходів до розуміння МПР

    Effect of standing posture during whole body vibration training on muscle morphology and function in older adults: A randomised controlled trial

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Whole body vibration (WBV) is a novel modality of exercise shown to improve musculoskeletal function. This study aims to examine the effects of standing posture during low magnitude WBV training on muscle function and muscle morphology in older adults.</p> <p>Methods</p> <p>Nineteen men and women (50-80 years) were recruited to a three month randomised controlled trial and allocated to one of three groups: WBV with flexed knees (FK), WBV with locked knees (LK), or sham WBV with flexed knees (CON). Exposure was intermittent (1 min WBV:1 min rest) for 20 min, three times per week for 13 weeks. Measurements were taken at baseline and at three months. Primary outcomes included upper and lower body muscle function (strength, power and velocity). Secondary outcomes were muscle morphology, balance, habitual and maximal gait velocity, stair climb power, and chair stand performance.</p> <p>Results</p> <p>Sixteen subjects completed the study. Relative (%) upper body contraction velocity improved significantly after WBV with FK compared to LK (FK 16.0%, LK -7.6%, CON 4.7, p = 0.01). Relative upper body strength (LK 15.1%, p = 0.02; FK 12.1%, p = 0.04; CON 4.7%) increased significantly following WBV compared to control. Absolute (p = 0.05) and relative (p = 0.03) lower leg strength significantly improved with both standing postures (LK 14.4%; FK 10.7%; CON 1.3%). Only the LK group differed significantly from CON in relative leg strength gains (p = 0.02). Potentially clinically meaningful but statistically non-significant improvements in lower leg muscle cross-sectional area (LK 3.7 cm<sup>2</sup>, FK 2.4 cm<sup>2</sup>, CON 2.2 cm<sup>2 </sup>p = 0.13) were observed after WBV with LK compared to the other groups. No significant effects of WBV on any functional performance tests were observed.</p> <p>Conclusions</p> <p>Our results suggest that WBV may improve muscle strength and contraction velocity in some muscle groups in older adults. However, hypothesised differential adaptation to standing posture (FK > LK) was observed only for upper body contraction velocity, making recommendations regarding this prescriptive element inconclusive. The efficacy, mechanism of action and long term feasibility of WBV for musculoskeletal health in older adults warrants continued investigation in robustly designed, sufficiently powered future studies.</p> <p>Trial Registration</p> <p>ACTRN12609000353291.</p

    The Development of Three Long Universal Nuclear Protein-Coding Locus Markers and Their Application to Osteichthyan Phylogenetics with Nested PCR

    Get PDF
    BACKGROUND: Universal nuclear protein-coding locus (NPCL) markers that are applicable across diverse taxa and show good phylogenetic discrimination have broad applications in molecular phylogenetic studies. For example, RAG1, a representative NPCL marker, has been successfully used to make phylogenetic inferences within all major osteichthyan groups. However, such markers with broad working range and high phylogenetic performance are still scarce. It is necessary to develop more universal NPCL markers comparable to RAG1 for osteichthyan phylogenetics. METHODOLOGY/PRINCIPAL FINDINGS: We developed three long universal NPCL markers (>1.6 kb each) based on single-copy nuclear genes (KIAA1239, SACS and TTN) that possess large exons and exhibit the appropriate evolutionary rates. We then compared their phylogenetic utilities with that of the reference marker RAG1 in 47 jawed vertebrate species. In comparison with RAG1, each of the three long universal markers yielded similar topologies and branch supports, all in congruence with the currently accepted osteichthyan phylogeny. To compare their phylogenetic performance visually, we also estimated the phylogenetic informativeness (PI) profile for each of the four long universal NPCL markers. The PI curves indicated that SACS performed best over the whole timescale, while RAG1, KIAA1239 and TTN exhibited similar phylogenetic performances. In addition, we compared the success of nested PCR and standard PCR when amplifying NPCL marker fragments. The amplification success rate and efficiency of the nested PCR were overwhelmingly higher than those of standard PCR. CONCLUSIONS/SIGNIFICANCE: Our work clearly demonstrates the superiority of nested PCR over the conventional PCR in phylogenetic studies and develops three long universal NPCL markers (KIAA1239, SACS and TTN) with the nested PCR strategy. The three markers exhibit high phylogenetic utilities in osteichthyan phylogenetics and can be widely used as pilot genes for phylogenetic questions of osteichthyans at different taxonomic levels

    Rapid progress on the vertebrate tree of life

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Among the greatest challenges for biology in the 21st century is inference of the tree of life. Interest in, and progress toward, this goal has increased dramatically with the growing availability of molecular sequence data. However, we have very little sense, for any major clade, of how much progress has been made in resolving a full tree of life and the scope of work that remains. A series of challenges stand in the way of completing this task but, at the most basic level, progress is limited by data: a limited fraction of the world's biodiversity has been incorporated into a phylogenetic analysis. More troubling is our poor understanding of what fraction of the tree of life is understood and how quickly research is adding to this knowledge. Here we measure the rate of progress on the tree of life for one clade of particular research interest, the vertebrates.</p> <p>Results</p> <p>Using an automated phylogenetic approach, we analyse all available molecular data for a large sample of vertebrate diversity, comprising nearly 12,000 species and 210,000 sequences. Our results indicate that progress has been rapid, increasing polynomially during the age of molecular systematics. It is also skewed, with birds and mammals receiving the most attention and marine organisms accumulating far fewer data and a slower rate of increase in phylogenetic resolution than terrestrial taxa. We analyse the contributors to this phylogenetic progress and make recommendations for future work.</p> <p>Conclusions</p> <p>Our analyses suggest that a large majority of the vertebrate tree of life will: (1) be resolved within the next few decades; (2) identify specific data collection strategies that may help to spur future progress; and (3) identify branches of the vertebrate tree of life in need of increased research effort.</p

    Neural Correlates of Behavioural Olfactory Sensitivity Changes Seasonally in European Starlings

    Get PDF
    Possibly due to the small size of the olfactory bulb (OB) as compared to rodents, it was generally believed that songbirds lack a well-developed sense of smell. This belief was recently revised by several studies showing that various bird species, including passerines, use olfaction in many respects of life. During courtship and nest building, male European starlings (Sturnus vulgaris) incorporate aromatic herbs that are rich in volatile compounds (e.g., milfoil, Achillea millefolium) into the nests and they use olfactory cues to identify these plants. Interestingly, European starlings show seasonal differences in their ability to respond to odour cues: odour sensitivity peaks during nest-building in the spring, but is almost non-existent during the non-breeding season.This study used repeated in vivo Manganese-enhanced MRI to quantify for the first time possible seasonal changes in the anatomy and activity of the OB in starling brains. We demonstrated that the OB of the starling exhibits a functional seasonal plasticity of certain plant odour specificity and that the OB is only able to detect milfoil odour during the breeding season. Volumetric analysis showed that this seasonal change in activity is not linked to a change in OB volume. By subsequently experimentally elevating testosterone (T) in half of the males during the non-breeding season we showed that the OB volume was increased compared to controls.By investigating the neural substrate of seasonal olfactory sensitivity changes we show that the starlings' OB loses its ability during the non-breeding season to detect a natural odour of a plant preferred as green nest material by male starlings. We found that testosterone, applied during the non-breeding season, does not restore the discriminatory ability of the OB but has an influence on its size
    corecore