168 research outputs found
Control synthesis for polynomial discrete-time systems under input constraints via delayed-state Lyapunov functions
This paper presents a discrete-time control design methodology for input-saturating systems using a Lyapunov function with dependence on present and past states. The approach is used to bypass the usual difficulty with full polynomial Lyapunov functions of expressing the problem in a convex way. Also polynomial controllers are allowed to depend on both present and past states. Furthermore, by considering saturation limits on the control action, the information about the relationship between the present and past states is introduced via Positivstellensatz multipliers. Sum-of-squares techniques and available semi-definite programming (SDP) software are used in order to find the controller.The research work by J.L. Pitarch and A. Sala has been partially supported by the Spanish government under research project [grant number DPI2011-27845-C02-01 (MINECO)]; Generalitat Valenciana [grant number PROMETEOII/2013/004]. The work by T.M. Guerra and J. Lauber has been supported by the International Campus on Safety and Intermodality in Transportation, the European Community, Delegation Regionale a la Recherche et a la Technologie, Ministere de l'Enseignement superieur et de la Recherche, Region Nord Pas de Calais and the Centre National de la Recherche Scientifique.Pitarch Pérez, JL.; Sala Piqueras, A.; Lauber, J.; Guerra, TM. (2016). Control synthesis for polynomial discrete-time systems under input constraints via delayed-state Lyapunov functions. International Journal of Systems Science. 47(5):1176-1184. https://doi.org/10.1080/00207721.2014.915357S1176118447
High contrast optical imaging of companions: the case of the brown dwarf binary HD-130948BC
High contrast imaging at optical wavelengths is limited by the modest
correction of conventional near-IR optimized AO systems.We take advantage of
new fast and low-readout-noise detectors to explore the potential of fast
imaging coupled to post-processing techniques to detect faint companions to
stars at small separations. We have focused on I-band direct imaging of the
previously detected brown dwarf binary HD130948BC,attempting to spatially
resolve the L2+L2 benchmark system. We used the Lucky-Imaging instrument
FastCam at the 2.5-m Nordic Telescope to obtain quasi diffraction-limited
images of HD130948 with ~0.1" resolution.In order to improve the detectability
of the faint binary in the vicinity of a bright (I=5.19 \pm 0.03) solar-type
star,we implemented a post-processing technique based on wavelet transform
filtering of the image which allows us to strongly enhance the presence of
point-like sources in regions where the primary halo dominates. We detect for
the first time the BD binary HD130948BC in the optical band I with a SNR~9 at
2.561"\pm 0.007" (46.5 AU) from HD130948A and confirm in two independent
dataset that the object is real,as opposed to time-varying residual speckles.We
do not resolve the binary, which can be explained by astrometric results
posterior to our observations that predict a separation below the NOT
resolution.We reach at this distance a contrast of dI = 11.30 \pm 0.11, and
estimate a combined magnitude for this binary to I = 16.49 \pm 0.11 and a I-J
colour 3.29 \pm 0.13. At 1", we reach a detectability 10.5 mag fainter than the
primary after image post-processing. We obtain on-sky validation of a technique
based on speckle imaging and wavelet-transform processing,which improves the
high contrast capabilities of speckle imaging.The I-J colour measured for the
BD companion is slightly bluer, but still consistent with what typically found
for L2 dwarfs(~3.4-3.6).Comment: accepted in A\&
Lucky Imaging Adaptive Optics of the brown dwarf binary GJ569Bab
The potential of combining Adaptive Optics (AO) and Lucky Imaging (LI) to
achieve high precision astrometry and differential photometry in the optical is
investigated by conducting observations of the close 0\farcs1 brown dwarf
binary GJ569Bab. We took 50000 -band images with our LI instrument FastCam
attached to NAOMI, the 4.2-m William Herschel Telescope (WHT) AO facility. In
order to extract the most of the astrometry and photometry of the GJ569Bab
system we have resorted to a PSF fitting technique using the primary star
GJ569A as a suitable PSF reference which exhibits an -band magnitude of
. The AO+LI observations at WHT were able to resolve the binary
system GJ569Bab located at 4\farcs 92 \pm 0\farcs05 from GJ569A. We measure a
separation of mas and -band magnitudes of
and and colors of 2.720.08 and 2.830.08 for
the Ba and Bb components, respectively. Our study rules out the presence of any
other companion to GJ569A down to magnitude I 17 at distances larger than
1\arcsec. The colors measured are consistent with M8.5-M9 spectral types
for the Ba and Bb components. The available dynamical, photometric and
spectroscopic data are consistent with a binary system with Ba being slightly
(10-20%) more massive than Bb. We obtain new orbital parameters which are in
good agreement with those in the literature.Comment: 13 pages, 9 figures, 7 tables, in press in MNRA
Cannabinoid receptor CB2 drives HER2 pro-oncogenic signaling in breast cancer
Pharmacological activation of cannabinoid receptors elicits antitumoral responses in different models of cancer. However, the biological role of these receptors in tumor physio-pathology is still unknown. We analyzed CB2 cannabinoid receptor protein expression in two series of 166 and 483 breast tumor samples operated in the University Hospitals of Kiel, Tübingen and Freiburg between 1997 and 2010. CB2 mRNA expression was also analyzed in previously published DNA microarray datasets. The role of CB2 in oncogenesis was studied by generating a mouse line that expresses the HER2 rat ortholog (neu) and lacks CB2, and by a variety of biochemical and cell biology approaches in human breast cancer cells in culture and in vivo, upon modulation of CB2 expression by si/shRNAs and overexpression plasmids. CB2-HER2 molecular interaction was studied by co-localization, coimmunoprecipitation and proximity ligation assays. We show an association between elevated CB2 expression in HER2+ breast tumors and poor patient prognosis. We also demonstrate that genetic inactivation of CB2 impairs tumor generation and progression in MMTV-neu mice. Moreover, we show that HER2 upregulates CB2 expression by activating the transcription factor ELK1 via the ERK cascade, and that an increased CB2 expression activates the HER2 prooncogenic signaling machinery at the level of the tyrosine kinase c-SRC. Finally, HER2 and CB2 form heteromers in cancer cells. Our findings reveal an unprecedented role of CB2 as a pivotal regulator of HER2 pro-oncogenic signaling in breast cancer, and suggest that CB2 may be a biomarker with prognostic value in these tumors
Water seepage beneath dams on soluble evaporite deposits: a laboratory and field study (Caspe Dam, Spain)
The paper presents analytical methods and results for assessing the variation in the concentration of sulphate (and other ions) over space and time in groundwater flowing through a soluble evaporite terrain beneath a dam. The influence of effective porosity, groundwater flow velocity and the specific rate of dissolution (K′) are considered. The theoretical analysis was tested in a scale model simulating a dam constructed on heavily karstified bedrock. A simple and useful method for assessing how much material is lost through dissolution and how the rate of dissolution changes over time is considered in the context of the Caspe Dam, Spain
Evidence for the Higgs-boson Yukawa coupling to tau leptons with the ATLAS detector
Results of a search for H → τ τ decays are presented, based on the full set of proton-proton collision data recorded by the ATLAS experiment at the LHC during 2011 and 2012. The data correspond to integrated luminosities of 4.5 fb−1 and 20.3 fb−1 at centre-of-mass energies of √s = 7 TeV and √s = 8 TeV respectively. All combinations of leptonic (τ → `νν¯ with ` = e, µ) and hadronic (τ → hadrons ν) tau decays are considered. An excess of events over the expected background from other Standard Model processes is found with an observed (expected) significance of 4.5 (3.4) standard deviations. This excess provides evidence for the direct coupling of the recently discovered Higgs boson to fermions. The measured signal strength, normalised to the Standard Model expectation, of µ = 1.43 +0.43 −0.37 is consistent with the predicted Yukawa coupling strength in the Standard Model
Clinical Presentation, Management, and Evolution of Lymphomas in Patients with Inflammatory Bowel Disease: An ENEIDA Registry Study
Simple Summary An increased risk of hematological malignancies, mainly lymphomas, has been described in patients with inflammatory bowel disease (IBD). Because there are scarce data about the management and evolution of lymphomas in patients with IBD, the aim of our study was to analyze these points in those patients with IBD and lymphoma diagnosis included in the prospectively maintained ENEIDA registry of GETECCU. We identified 52 patients (2.4 cases of lymphoma/1000 patients with IBD). We found that most IBD patients had been treated with thiopurines and/or anti-TNF agents before lymphoma diagnosis, and these patients were younger at diagnosis of lymphoma than those not treated with these drugs. Relapse and mortality of lymphoma were not related with these therapies. The five-year survival rate was 85% for non-Hodgkin lymphoma and 84% in patients with Hodgkin lymphoma. An increased risk of lymphoma has been described in patients with inflammatory bowel disease (IBD). The aims of our study were to determine the clinical presentation, the previous exposure to immunosuppressive and biologic therapies, and the evolution of lymphomas in patients with IBD. IBD patients with diagnosis of lymphoma from October 2006 to June 2021 were identified from the prospectively maintained ENEIDA registry of GETECCU. We identified 52 patients (2.4 cases of lymphoma/1000 patients with IBD; 95% CI 1.8-3.1). Thirty-five were men (67%), 52% had ulcerative colitis, 60% received thiopurines, and 38% an anti-TNF drug before lymphoma diagnosis. Age at lymphoma was lower in those patients treated with thiopurines (53 +/- 17 years old) and anti-TNF drugs (47 +/- 17) than in those patients not treated with these drugs (63 +/- 12; p < 0.05). Five cases had relapse of lymphoma (1.7 cases/100 patient-years). Nine patients (17%) died after 19 months (IQR 0-48 months). Relapse and mortality were not related with the type of IBD or lymphoma, nor with thiopurines or biologic therapies. In conclusion, most IBD patients had been treated with thiopurines and/or anti-TNF agents before lymphoma diagnosis, and these patients were younger at diagnosis of lymphoma than those not treated with these drugs. Relapse and mortality of lymphoma were not related with these therapies
New GOLD classification: Longitudinal data on group assignment
Rationale:
Little is known about the longitudinal changes associated with using the 2013 update of the multidimensional GOLD strategy for chronic obstructive pulmonary disease (COPD).
Objective:
To determine the COPD patient distribution of the new GOLD proposal and evaluate how this classification changes over one year compared with the previous GOLD staging based on spirometry only.
Methods:
We analyzed data from the CHAIN study, a multicenter observational Spanish cohort of COPD patients who are monitored annually. Categories were defined according to the proposed GOLD: FEV1%, mMRC dyspnea, COPD Assessment Test (CAT), Clinical COPD Questionnaire (CCQ), and exacerbations-hospitalizations. One-year follow-up information was available for all variables except CCQ data.
Results:
At baseline, 828 stable COPD patients were evaluated. On the basis of mMRC dyspnea versus CAT, the patients were distributed as follows: 38.2% vs. 27.2% in group A, 17.6% vs. 28.3% in group B, 15.8% vs. 12.9% in group C, and 28.4% vs. 31.6% in group D. Information was available for 526 patients at one year: 64.2% of patients remained in the same group but groups C and D show different degrees of variability. The annual progression by group was mainly associated with one-year changes in CAT scores (RR, 1.138; 95%CI: 1.074-1.206) and BODE index values (RR, 2.012; 95%CI: 1.487-2.722).
Conclusions:
In the new GOLD grading classification, the type of tool used to determine the level of symptoms can substantially alter the group assignment. A change in category after one year was associated with longitudinal changes in the CAT and BODE index
Diet quality index as a predictor of treatment efficacy in overweight and obese adolescents: The EVASYON study
Background & aim: A diet quality index (DQI) is a tool that provides an overall score of an individual''s dietary intake when assessing compliance with food-based dietary guidelines. A number of DQIs have emerged, albeit their associations with health-related outcomes are debated. The aim of the present study was to assess whether adherence to dietary intervention, and the overall quality of the diet, can predict body composition changes. Methods: To this purpose, overweight/obese adolescents (n = 117, aged: 13–16 years; 51 males, 66 females) were recruited into a multi-component (diet, physical activity and psychological support) family-based group treatment programme. We measured the adolescents’ compliance and body composition at baseline and after 2 months (intensive phase) and 13 months (extensive phase) of follow-up. Also, at baseline, after 6 months, and at the end of follow-up we calculated the DQI. Results: Global compliance with the dietary intervention was 37.4% during the intensive phase, and 14.3% during the extensive phase. Physical activity compliance was 94.1% at 2-months and 34.7% at 13months and psychological support compliance were growing over the intervention period (10.3% intensive phase and 45.3% during extensive phase). Adolescents complying with the meal frequency criteria at the end of the extensive phase had greater reductions in FMI z-scores than those did not complying (Cohen''s d = 0.53). A statistically significant association was observed with the diet quality index. DQI-A variation explained 98.1% of BMI z-score changes and 95.1% of FMI changes. Conclusions: We conclude that assessment of changes in diet quality could be a useful tool in predicting body composition changes in obese adolescents involved in a diet and physical activity intervention programme backed-up by psychological and family support
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