Dynamic cofilin phosphorylation in the control of lamellipodial actin homeostasis

During animal cell chemotaxis, signalling at the plasma membrane induces actin polymerisation to drive forward cell movement. Since the cellular pool of actin is limited, efficient protrusion formation also requires the coordinated disassembly of pre-existing actin filaments. To search for proteins that can monitor filamentous and globular actin levels to maintain the balance of polymerisation and disassembly, we followed changes in the proteome induced by RNA interference (RNAi)mediated alterations in actin signalling. This unbiased approach revealed an increase in the levels of an inactive, phosphorylated form of the actin-severing protein cofilin in cells unable to generate actin-based lamellipodia. Conversely, an increase in F-actin levels induced the dephosphorylation and activation of cofilin via activation of the Ssh phosphatase. Similarly, in the context of acute phosphoinositide 3-kinase (PI3K) signalling, dynamic changes in cofilin phosphorylation were found to depend on the Ssh phosphatase and on changes in lamellipodial Factin. These results indicate that changes in the extent of cofilin phosphorylation are regulated by Ssh in response to changes in the levels and/or organisation of F-actin. Together with the recent finding that Ssh phosphatase activity is augmented by F-actin binding, these results identify Ssh-dependent regulation of phosphorylated cofilin levels as an important feedback control mechanism that maintains actin filament homeostasis during actin signalling

The Sentinel-1 constellation for InSAR applications: Experiences from the InSARAP project

The two-satellite Copernicus Sentinel-1 (S1) constellation became operational in Sep 2016, with the successful in-orbit commissioning of the S1B unit. During, the commissioning phase and early operational phase it has been confirmed that the interferometric performance of the constellation is excellent, with no observed phase anomalies. In this work, we show an analysis of selected performance parameters for the S1 constellation, as well as initial results based on the available data from the first months of operations

Changes in symptoms of asthma and rhinitis by sensitization status over ten years in a cohort of young Chilean adults

BACKGROUND: We investigated the net changes in prevalence of symptoms of asthma and rhinitis over 10 years in a cohort of young by baseline sensitization status. METHODS: One thousand one hundred ninety three Chilean adults subjects aged 22-28 living in a semi-rural area of central Chile answered a lifestyle and the European Community Respiratory Health Survey (ECRHS) questionnaires. Bronchial hyper-responsiveness (BHR) and skin prick test (SPT) to eight allergens were measured at baseline in 2001. Ten years later, 772 participants completed the questionnaires again. Estimates of adjusted net changes in prevalence of symptoms by sensitization status at baseline and association between sensitization status at baseline and respiratory symptoms ten years later were assessed. RESULTS: A quarter of the participants were sensitized to at least one allergen in 2001. Prevalence of wheeze had a net change per year of -0.37 % (95 % Confidence Interval -0.71 to 0.02 %; p = 0.067). Self-reported nasal allergies in the last 12 months increased by 0.83 % per year (95 % CI 0.49 to 1.17 %; p < 0.001). Those sensitized to either cat fur (OR 1.76; CI 1.01 to 3.05), cockroach, (OR 2.09; 1.13 to 3.86) blend of grass and pollens (1.78; 95 % CI 1.08 to 2.92), or weeds (OR 1.77; 95 % CI 1.01 to 3.12) in 2001 were more likely to have wheeze in the last 12 months 10 years later. CONCLUSION: Symptoms of asthma remained stable or slightly changed over 10 years in adults, whilst rhinitis and nasal allergies greatly increased. Being sensitized to at least one allergen is a risk factor for persistent symptoms of asthma and rhinitis, but not for determining net changes of symptoms over time. The underlying causes for the contrasting trends between asthma and nasal allergy are unknow

Mightyl: A compositional translation from mitl to timed automata

Metric Interval Temporal Logic (MITL) was first proposed in the early 1990s as a specification formalism for real-time systems. Apart from its appealing intuitive syntax, there are also theoretical evidences that make MITL a prime real-time counterpart of Linear Temporal Logic (LTL). Unfortunately, the tool support for MITL verification is still lacking to this day. In this paper, we propose a new construction from MITL to timed automata via very-weak one-clock alternating timed automata. Our construction subsumes the well-known construction from LTL to Büchi automata by Gastin and Oddoux and yet has the additional benefits of being compositional and integrating easily with existing tools. We implement the construction in our new tool MightyL and report on experiments using Uppaal and LTSmin as back-ends

Extra-curricular physical activity and socioeconomic status in Italian adolescents

BACKGROUND: The relationship between physical activity and health status has been thoroughly investigated in several studies, while the relation between physical activity and socio-economic status (SES) is less investigated. The aim of this study was to measure the extra-curricular physical activity of adolescents related to the socio-economic status (SES) of their families. METHODS: The survey was carried out by submitting an anonymous questionnaire to junior high school students in the following Regions: Lazio, Abruzzo, Molise, Campania, Puglia, during the school year 2002–2003. Extra-curriculum physical activity was evaluated considering whether or not present and hours of activity weekly conducted. 2411 students agreed to participate in the study. RESULTS: Participants were 1121 males (46.5%) and 1290 females (53.5%), aged between 11 and 17 years (median age: 12 years). 71.1% of the students reported to practice extra-curricular physical activity. Parents' educational levels and work activities play an important role in predicting students' physical activity, with the more remunerative activities and higher educational levels being more predictive. CONCLUSION: The results confirm the relationship between adolescents' physical activity and their families' SES. In particular, a positive relationship between participation in extra-curricular physical activity and their families high SES was found. These data will be useful for school administrators and for politicians in order to reduce the gap between adolescents from the least and most disadvantaged families

Mid-infrared passively switched pulsed dual wavelength Ho3+ -doped fluoride fiber laser at 3 μm and 2 μm

Cascade transitions of rare earth ions involved in infrared host fiber provide the potential to generate dual or multiple wavelength lasing at mid-infrared region. In addition, the fast development of saturable absorber (SA) towards the long wavelengths motivates the realization of passively switched mid-infrared pulsed lasers. In this work, by combing the above two techniques, a new phenomenon of passively Q-switched ~3 μm and gain-switched ~2 μm pulses in a shared cavity was demonstrated with a Ho3+-doped fluoride fiber and a specifically designed semiconductor saturable absorber (SESAM) as the SA. The repetition rate of ~2 μm pulses can be tuned between half and same as that of ~3 μm pulses by changing the pump power. The proposed method here will add new capabilities and more flexibility for generating mid-infrared multiple wavelength pulses simultaneously that has important potential applications for laser surgery, material processing, laser radar, and free-space communications, and other areas

Inter-observer agreement in the assessment of endoscopic findings in ulcerative colitis

BACKGROUND: Endoscopic findings are essential in evaluating the disease activity in ulcerative colitis. The aim of this study was to evaluate how endoscopists assess individual endoscopic features of mucosal inflammation in ulcerative colitis, the inter-observer agreement, and the importance of the observers' experience. METHODS: Five video clips of ulcerative colitis were shown to a group of experienced and a group of inexperienced endoscopists. Both groups were asked to assess eight endoscopic features and the overall mucosal inflammation on a visual analogue scale. The following statistical analyses were used; Contingency tables analysis, kappa analysis, analysis of variance, Pearson linear correlation analysis, general linear models, and agreement analysis. All tests were carried out two-tailed, with a significance level of 5%. RESULTS: The inter-observer agreement ranged from very good to moderate in the experienced group and from very good to fair in the inexperienced group. There was a significantly better inter-observer agreement in the experienced group in the rating of 6 out of 9 features (p < 0.05). The experienced and inexperienced endoscopists scored the "ulcerations" significantly different. (p = 0.05). The inter-observer variation of the mean score of "erosions", "ulcerations" and endoscopic activity index in mild disease, and the scoring of "erythema" and "oedema" in moderate-severe disease was significantly higher in the inexperienced group. A correlation was seen between all the observed endoscopic features in both groups of endoscopists. Among experienced endoscopists, a set of four endoscopic variables ("Vascular pattern", "Erosions", "Ulcerations" and Friability") explained 92% of the variation in EAI. By including "Granularity" in these set 91% of the variation in EAI was explained in the group of inexperienced endoscopists. CONCLUSION: The inter-observer agreement in the rating of endoscopic features characterising ulcerative colitis is satisfactory in both groups of endoscopists but significantly higher in the experienced group. The difference in the mean score between the two groups is only significant for "ulcerations". The endoscopic variables "Vascular pattern", "Erosions", "Ulcerations" and Friability" explained the overall endoscopic activity index. Even though the present result is quite satisfactory, there is a potential of improvement. Improved grading systems might contribute to improve the consistency of endoscopic descriptions