80 research outputs found

    Limitations of Algebraic Approaches to Graph Isomorphism Testing

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    We investigate the power of graph isomorphism algorithms based on algebraic reasoning techniques like Gr\"obner basis computation. The idea of these algorithms is to encode two graphs into a system of equations that are satisfiable if and only if if the graphs are isomorphic, and then to (try to) decide satisfiability of the system using, for example, the Gr\"obner basis algorithm. In some cases this can be done in polynomial time, in particular, if the equations admit a bounded degree refutation in an algebraic proof systems such as Nullstellensatz or polynomial calculus. We prove linear lower bounds on the polynomial calculus degree over all fields of characteristic different from 2 and also linear lower bounds for the degree of Positivstellensatz calculus derivations. We compare this approach to recently studied linear and semidefinite programming approaches to isomorphism testing, which are known to be related to the combinatorial Weisfeiler-Lehman algorithm. We exactly characterise the power of the Weisfeiler-Lehman algorithm in terms of an algebraic proof system that lies between degree-k Nullstellensatz and degree-k polynomial calculus

    Rotura bilateral y simultánea del tendón de Aquiles

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    La rotura bilateral y simultánea del tendón de Aquiles es un hecho excepcional. La producción de esta lesión en una persona joven, sin antecedentes patológicos ni de administración de ciertos medicamentos es aún más excepcional. El tratamiento quirúrgico y un adecuado proceso de seguimiento y rehabilitación contribuyen a una buena recuperación y pronóstico en los individuos jóvenes y activos con roturas del tendón de Aquiles. Se presenta un caso clínico de una mujer de 21 años tratada quirúrgicamente con buen resultado.The bilateral and simultaneous rupture of Achilles tendon is an excepcional situation. The production of this injury in a young person, without history pathological or administration of certain drugs is even more exceptional. The surgical treatment and a proper process of following-up and rehabilitation help to a good recovery and prognosis in young and active people with Achilles tendon ruptures

    Notch-mediated induction of N-cadherin and α 9-integrin confers higher invasive phenotype on rhabdomyosarcoma cells

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    Altres ajuts: This work was supported by grants from Institut Català d'Oncologia (ICO), Instituto de Salud Carlos III (RD06/0020/1021 and PI11/00740), Fundació la Marató de TV3, Asociación Española Contra el Cáncer, Fundació SMALL and Fundació A. BOSCH.Rhabdomyosarcoma (RMS) is the commonest type of soft-tissue sarcoma in children. Patients with metastatic RMS continue to have very poor prognosis. Recently, several works have demonstrated a connection between Notch pathway activation and the regulation of cell motility and invasiveness. However, the molecular mechanisms of this possible relationship remain unclear. The Notch pathway was manipulated pharmacologically and genetically. The mRNA changes were analysed by quantitative PCR and protein variations by western blot and immunofluorescence. Finally, the capabilities of RMS cells to adhere, heal a wound and invade were assessed in the presence of neuronal cadherin (N-cadherin)- and α 9-integrin-blocking antibodies. Cells treated with γ -secretase inhibitor showed lower adhesion capability and downregulation of N-cadherin and α 9-integrin. Genetic manipulation of the Notch pathway led to concomitant variations in N-cadherin and α 9-integrin. Treatment with anti-N-cadherin-blocking antibody rendered marked inhibition of cell adhesion and motility, while anti- α 9-integrin-blocking antibody exerted a remarkable effect on cell adhesion and invasiveness. Neuronal cadherin and α 9-integrin are postulated as leading actors in the association between the Notch pathway and promotion of cell adhesion, motility and invasion, pointing to these proteins and the Notch pathway itself as interesting putative targets for new molecular therapies against metastases in RMS

    "Ethnic disparities in the prevalence of Molar-Incisor-Hypomineralisation (MIH) and caries among 6-12-year-old children in Catalonia, Spain"

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    AIM: To study the prevalence of MIH and caries in 6- and 12-year-old schoolchildren and their association with ethnic disparities and other relevant factors. BACKGROUND: In recent years, there has been uneven improvement in school children's oral health, highlighting inequalities in access to dental care and health outcomes, particularly among ethnic minorities. The most prevalent oral disease in childhood, caries, is preventable, as its risk factors are well known. However, MIH, a common condition affecting the enamel of permanent incisors and/or molars, has no established aetiology or preventive measures. METHODS: A cross-sectional study among schoolchildren was conducted in 725 children from Masnou (Barcelona, 2013) and in 577 children from Sant Andreu de Llavaneres (Barcelona, 2018-2020). Data collection was carried out by means of clinical examination and a selfreferenced questionnaire. Oral health outcomes included: presence of dental caries, presence of MIH, hypomineralised second primary molars (HSPM). All variables were analysed according to ethnic disparities and other variables such as socioeconomics, diet, hygiene habits, plaque and access to dental services. We performed multivariate Poisson regression models with robust variance to examine ethnic disparities in MIH and caries. CONCLUSION: This cross-sectional study based in Catalonia, Spain showed that there are ethnic disparities in caries as observed with other child's diseases; however, they do not seem to follow the same pattern for MIH. More studies are needed (i) to explore how MIH behaves among populations in terms of inequality; (ii) to study the aetiological factors of MIH; and (iii) to identify potential factors associated with MIH and caries that have not been studied and that may contribute to the observed ethnic disparities.</p

    "Ethnic disparities in the prevalence of Molar-Incisor-Hypomineralisation (MIH) and caries among 6-12-year-old children in Catalonia, Spain"

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    AIM: To study the prevalence of MIH and caries in 6- and 12-year-old schoolchildren and their association with ethnic disparities and other relevant factors. BACKGROUND: In recent years, there has been uneven improvement in school children's oral health, highlighting inequalities in access to dental care and health outcomes, particularly among ethnic minorities. The most prevalent oral disease in childhood, caries, is preventable, as its risk factors are well known. However, MIH, a common condition affecting the enamel of permanent incisors and/or molars, has no established aetiology or preventive measures. METHODS: A cross-sectional study among schoolchildren was conducted in 725 children from Masnou (Barcelona, 2013) and in 577 children from Sant Andreu de Llavaneres (Barcelona, 2018-2020). Data collection was carried out by means of clinical examination and a selfreferenced questionnaire. Oral health outcomes included: presence of dental caries, presence of MIH, hypomineralised second primary molars (HSPM). All variables were analysed according to ethnic disparities and other variables such as socioeconomics, diet, hygiene habits, plaque and access to dental services. We performed multivariate Poisson regression models with robust variance to examine ethnic disparities in MIH and caries. CONCLUSION: This cross-sectional study based in Catalonia, Spain showed that there are ethnic disparities in caries as observed with other child's diseases; however, they do not seem to follow the same pattern for MIH. More studies are needed (i) to explore how MIH behaves among populations in terms of inequality; (ii) to study the aetiological factors of MIH; and (iii) to identify potential factors associated with MIH and caries that have not been studied and that may contribute to the observed ethnic disparities.</p

    Effectiveness and safety of a microcrystalline tyrosine‐adjuvanted <i>Dermatophagoides pteronyssinus</i> allergoid immunotherapy in adult patients with allergic asthma and rhinitis: A real‐life prospective observational study

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    Introduction: Although clinical trials have shown the efficacy and safety of allergen-specific immunotherapy (AIT) in the treatment of allergic asthma, there is a need for real-life studies. We aimed to assess the effectiveness and safety of a microcrystalline tyrosine-adjuvanted Dermatophagoides pteronyssinus allergoid (Acarovac Plus (R)) in patients with house dust mite (HDM)-induced allergic asthma in a real-life study. Methods: A subanalysis of a multicenter, prospective, observational, real-life study. Patients with rhinitis and allergic asthma caused by HDMs were assessed before AIT with Acarovac Plus (R) and at 6 and 12 months after this treatment. Assessment parameters were percentage of days with asthma symptoms, percentage of days on asthma medication, classification of asthma according to Spanish guidelines for the management of asthma, asthma-related quality of life (quality of life in adults with asthma questionnaire [QLAAQ]), perception of symptoms (visual analog scale [VAS]), and treatment satisfaction (treatment satisfaction questionnaire for medication [TSQM]). Safety was assessed by the number and severity of adverse reactions. Results: This subanalysis included 55 patients. Treatment with Acarovac Plus (R) showed significant differences in the analyzed variables when the baseline visit was compared with the 12-month visit: reduction of the mean (SD) percentage of days with asthma symptoms (23.9 [9.2] vs. 5.1 [12.8]; p = .002), of the mean [SD] percentage of days on asthma medication (67.6 [42.9] vs. 45.1 [46.8]; p = .002), and of the percentage of patients with persistent asthma (78.2% vs. 38.9%; p = .009). Acarovac Plus (R) significantly improved asthma-related quality of life, as shown by a decrease of 1.39 points in QLAAQ score at 12 months (p < .001), and in the subjective perception of symptoms on the VAS (-3.50, p < .0001). Patients showed high treatment satisfaction according to the TSQM, and it was well tolerated. No serious adverse events were reported. Conclusions: Acarovac Plus (R) was effective and safe for the treatment of patients with HDM-induced allergic asthma in a real-life study

    Asistencia urgente a pacientes con infección por el virus de la inmunodeficiencia humana: un problema que crece

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    La asistencia médica a pacientes con infección por el virus de la inmunodeficiencia humana (VIH) es habitualmente compleja debido a las características peculiares de esta enfermedad y al gran número de complicaciones infecciosas, metabólicas, neurológicas y en general, de todo tipo que presentan 1.3. Estos factores y la potencial gravedad que pueden representar, hace que con frecuencia estos pacientes soliciten asistencia médica en régimen urgente. La atención urgente a este colectivo de pacientes está poco organizada a nivel sanitario en nuestro país, ya que no se ha creado un dispositivo de asistencia sanitaria específica y la atención ambulatoria que reciben es claramente insuficiente

    Understanding the discriminant factors that influence the adoption and use of clinical communities of practice : the ECOPIH case

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    The aim of the study presented in this article is to analyse the discriminant factors that have an influence on the use of communities of practice by primary and specialist healthcare professionals (physicians and nurses) for information sharing. Obtaining evidence from an ex-ante analysis to determine what factors explain healthcare professionals' clinical community of practice use allows aspects of its use to be identified. A theoretical model based on a modified technology acceptance model was used as the analysis tool, and a discriminant analysis was performed. An ad-hoc questionnaire was designed and sent to a study population of 357 professionals from the Badalona-Sant Adrià de Besòs Primary Care Service in Catalonia, Spain, which includes nine primary care centres and three specialist care centres. The study sample was formed by the 166 healthcare professionals who responded. The results revealed three main drivers for engagement in a CoP: First, for the whole sample, perceived usefulness for reducing costs associated with clinical practice was the factor with the greatest discriminant power that distinguished between users and non-users, followed by perceived usefulness for improving clinical practice quality, and lastly habitual social media website and application use. Turning to the two sub-samples of healthcare professions (physicians and nurses, respectively), we saw that the usefulness stemming from community of practice use changed. There were differences in the levels of motivation of healthcare professionals with regards to their engagement with CoP. While perceived usefulness for reducing costs associated with clinical practice was the main factor for the physicians, perceived usefulness of the Web 2.0 platform use for communication for improving clinical practice quality and perceived ease of use were the main factors for the nurses. In the context of communities of practice, the perception of usefulness of Web 2.0 platform use for communication is determined by organisational, technological and social factors. Specifically, the position that professionals have within the healthcare structure and particularly the closer healthcare professionals' activity is to patients and their professional experience of using social networks and ICTs are crucial to explaining the use of such platforms. Public policies promoting Web 2.0 platform use for communication should therefore go beyond the purely technological dimension and consider other professional and social determinants

    Unified characterisations of resolution hardness measures

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    Various "hardness" measures have been studied for resolution, providing theoretical insight into the proof complexity of resolution and its fragments, as well as explanations for the hardness of instances in SAT solving. In this paper we aim at a unified view of a number of hardness measures, including different measures of width, space and size of resolution proofs. Our main contribution is a unified game-theoretic characterisation of these measures. As consequences we obtain new relations between the different hardness measures. In particular, we prove a generalised version of Atserias and Dalmau's result on the relation between resolution width and space from [5]

    Immunological parameters as biomarkers of response to MicroCrystalline Tyrosine-adjuvanted mite immunotherapy

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    Despite the effectiveness of allergen immunotherapy (AIT), some patients are unresponsive for reasons still unknown; yet validated response biomarkers remain unavailable. To analyze immunological parameters as biomarkers to monitor and predict clinical response to a MicroCrystalline Tyrosine-adjuvanted house dust mite (HDM) AIT in patients with allergic rhinitis (AR). Observational, prospective, multicenter study including adult patients (aged 18-65 years) with AR, with and without asthma, sensitized to the HDM Dermatophagoides pteronyssinus (DP) and prescribed Acarovac Plus® DP 100% in the routine practice. Serum concentrations of total IgE, specific IgE, specific IgG4, IL-4, IL-5, IL-10, IL-13, and IFN-γ were compared between baseline and 12 months after AIT. The relationship between patients' baseline immunological profiles and classification as low, high, and non-responders and between their sensitization profile to DP allergens and effectiveness were analyzed. Of 141 patients recruited, 118 (mean [SD] age of 33.6 [9.5] years) were evaluable. One year after treatment, Der p 1-specific IgE, DP-specific IgG4, and IL-10 increased by a mean (SD) of 3.4 (13.6) kU/L (p = 0.016), 0.43 (0.55) mg/L (p < 0.0001), and 1.35 (7.56) pg/mL (p = 0.033), respectively. Non-responders showed increased baseline levels of IL-13 compared to high responders (p = 0.037). Changes in effectiveness variables between baseline and after AIT were similar regardless of the sensitization profile. Non-responsive patients to AIT showed increased baseline IL-13 concentrations, suggesting its value as prognostic biomarker. DP-specific AIT increased Der p 1-specific IgE, DP-specific IgG4, and IL-10 concentrations in patients with AR. All patients benefited from treatment regardless of their sensitization profile to major DP allergens
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