12 research outputs found

    Andronov-Hopf and Bautin bifurcation in a tritrophic food chain model with Holling functional response types IV and II

    Get PDF
    The existence of an Andronov–Hopf and Bautin bifurcation of a given system of differential equations is shown. The system corresponds to a tritrophic food chain model with Holling functional responses type IV and II for the predator and superpredator, respectively. The linear and logistic growth is considered for the prey. In the linear case, the existence of an equilibrium point in the positive octant is shown and this equilibrium exhibits a limit cycle. For the logistic case, the existence of three equilibrium points in the positive octant is proved and two of them exhibit a simultaneous Hopf bifurcation. Moreover the Bautin bifurcation on these points are shown

    Comprehensive description of clinical characteristics of a large systemic Lupus Erythematosus Cohort from the Spanish Rheumatology Society Lupus Registry (RELESSER) with emphasis on complete versus incomplete lupus differences

    Get PDF
    Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by multiple organ involvement and pronounced racial and ethnic heterogeneity. The aims of the present work were (1) to describe the cumulative clinical characteristics of those patients included in the Spanish Rheumatology Society SLE Registry (RELESSER), focusing on the differences between patients who fulfilled the 1997 ACR-SLE criteria versus those with less than 4 criteria (hereafter designated as incomplete SLE (iSLE)) and (2) to compare SLE patient characteristics with those documented in other multicentric SLE registries. RELESSER is a multicenter hospital-based registry, with a collection of data from a large, representative sample of adult patients with SLE (1997 ACR criteria) seen at Spanish rheumatology departments. The registry includes demographic data, comprehensive descriptions of clinical manifestations, as well as information about disease activity and severity, cumulative damage, comorbidities, treatments and mortality, using variables with highly standardized definitions. A total of 4.024 SLE patients (91% with ≄4 ACR criteria) were included. Ninety percent were women with a mean age at diagnosis of 35.4 years and a median duration of disease of 11.0 years. As expected, most SLE manifestations were more frequent in SLE patients than in iSLE ones and every one of the ACR criteria was also associated with SLE condition; this was particularly true of malar rash, oral ulcers and renal disorder. The analysis-adjusted by gender, age at diagnosis, and disease duration-revealed that higher disease activity, damage and SLE severity index are associated with SLE [OR: 1.14; 95% CI: 1.08-1.20 (P < 0.001); 1.29; 95% CI: 1.15-1.44 (P < 0.001); and 2.10; 95% CI: 1.83-2.42 (P < 0.001), respectively]. These results support the hypothesis that iSLE behaves as a relative stable and mild disease. SLE patients from the RELESSER register do not appear to differ substantially from other Caucasian populations and although activity [median SELENA-SLEDA: 2 (IQ: 0-4)], damage [median SLICC/ACR/DI: 1 (IQ: 0-2)], and severity [median KATZ index: 2 (IQ: 1-3)] scores were low, 1 of every 4 deaths was due to SLE activity. RELESSER represents the largest European SLE registry established to date, providing comprehensive, reliable and updated information on SLE in the southern European population

    Andronov–Hopf and Bautin bifurcation in a tritrophic food chain model with Holling functional response types IV and II

    No full text
    The existence of an Andronov–Hopf and Bautin bifurcation of a given system of differential equations is shown. The system corresponds to a tritrophic food chain model with Holling functional responses type IV and II for the predator and superpredator, respectively. The linear and logistic growth is considered for the prey. In the linear case, the existence of an equilibrium point in the positive octant is shown and this equilibrium exhibits a limit cycle. For the logistic case, the existence of three equilibrium points in the positive octant is proved and two of them exhibit a simultaneous Hopf bifurcation. Moreover the Bautin bifurcation on these points are shown

    Botrytis cinerea Pers. in postharvest apple fruit, control with Candida oleophila Montrocher strains and/or synthetic fungicides

    No full text
    As an alternative control method, to improve control and to reduce synthetic fungicide use, three Candida oleophila strains and/or four commercial synthetic fungicides were used to control Botrytis cinerea damage on postharvest apple fruit. Synthetic commercial fungicides; Cyprodinil+Fludioxonil, Thiabendazole and Benomyl, allowed Candida oleophila strains colony growth when challenged to the pressure of these fungicides. Synthetic commercial fungicide Captan did not allow any Candida oleophila strains colony growth. Control of Botrytis cinerea expressed in % of damage and damage reduction, gave an average control of; 100% for Cyprodinil+Fludioxonil; Captan, 97.5%; Thiabendazole, 94.1% and Benomyl, 93.7% All Candida oleophila strains, individually, gave a 100% control. Thiabendazole and Benomyl improved their efficiency to control Botrytis cinerea when combined with Candida oleophila. Control of Botrytis cinerea damage on postharvest Golden Delicious apple fruit can be achieved up to 100% either with Candida oleophila strains individually and/or with Cyprodinil+Fludioxonil alone. The use of Candida oleophila as an alternative method to control Botrytis cinerea damage on postharvest apple fruit means a reduction of synthetic fungicide use, plus avoiding fungicide residues on the treated apple fruit and on the environment, thus reducing the risk for human health damage.Un método alternativo de control, para incrementar el control y para reducir el uso de fungicidas sintéticos, tres cepas de Candida oleophila y/o cuatro fungicidas sintéticos comerciales fueron utilizados para el control del daño provocado por Botrytis cinerea en manzana en poscosecha. Los fungicidas sintéticos; Cyprodinil+Fludioxonil, Tiabendazol y Benomilo, permitieron el crecimiento de las cepas de Candida oleophila cuando fueron sometidas a la presión de éstos. El fungicida Captan no permitió el crecimiento de ninguna de las cepas de Candida oleophila. El control del daño provocado por Botrytis cinerea expresado en % y reducción de éste, promedió un control del; 100% para el Cyprodinil+Fludioxonil; Captan, 97.5%; Tiabendazol, 94.1 y Benomilo, 93.7%. Todas las cepas de Candida oleophila, individualmente, controlaron al 100%. El Tiabendazol y el Benomilo mejoraron su control contra Botrytis cinerea cuando se combinaron con Candida oleophila. Un control del 100% del daño provocado por Botrytis cinerea en manzana Golden Delicious en poscosecha se logra utilizando las cepas de Candida oleophila de manera individual o con Cyprodinil+Fludioxonil solo. El uso de Candida oleophila como un método alternativo para el control del daño provocado por Botrytis cinerea en manzana en poscosecha significa una reducción del uso de fungicidas sintéticos, evitando también la presencia de residuos del fungicida en la manzana tratada y en el medio ambiente, reduciendo así el riesgo de daño para humanos

    Incidence, associated factors and clinical impact of severe infections in a large, multicentric cohort of patients with systemic lupus erythematosus.

    No full text
    To estimate the incidence of severe infection and investigate the associated factors and clinical impact in a large systemic lupus erythematosus (SLE) retrospective cohort. All patients in the Spanish Rheumatology Society Lupus Registry (RELESSER) who meet ≄4 ACR-97 SLE criteria were retrospectively investigated for severe infections. Patients with and without infections were compared in terms of SLE severity, damage, comorbidities, and demographic characteristics. A multivariable Cox regression model was built to calculate hazard ratios (HRs) for the first infection. A total of 3658 SLE patients were included: 90% female, median age 32.9 years (DQ 9.7), and mean follow-up (months) 120.2 (±87.6). A total of 705 (19.3%) patients suffered ≄1 severe infection. Total severe infections recorded in these patients numbered 1227. The incidence rate was 29.2 (95% CI: 27.6-30.9) infections per 1000 patient years. Time from first infection to second infection was significantly shorter than time from diagnosis to first infection (p Severe infection constitutes a predictor of poor prognosis in SLE patients, is more common in Latin-Americans and is associated with age, previous infection, and smoking. Antimalarials exerted a protective effect

    Relationship between damage clustering and mortality in systemic lupus erythematosus in early and late stages of the disease: cluster analyses in a large cohort from the Spanish Society of Rheumatology Lupus Registry.

    No full text
    To identify patterns (clusters) of damage manifestations within a large cohort of SLE patients and evaluate the potential association of these clusters with a higher risk of mortality. This is a multicentre, descriptive, cross-sectional study of a cohort of 3656 SLE patients from the Spanish Society of Rheumatology Lupus Registry. Organ damage was ascertained using the Systemic Lupus International Collaborating Clinics Damage Index. Using cluster analysis, groups of patients with similar patterns of damage manifestations were identified. Then, overall clusters were compared as well as the subgroup of patients within every cluster with disease duration shorter than 5 years. Three damage clusters were identified. Cluster 1 (80.6% of patients) presented a lower amount of individuals with damage (23.2 vs 100% in clusters 2 and 3, P In a large cohort of SLE patients, cardiovascular and musculoskeletal damage manifestations were the two dominant forms of damage to sort patients into clinically meaningful clusters. Both in early and late stages of the disease, there was a significant association of these clusters with an increased risk of mortality. Physicians should pay special attention to the early prevention of damage in these two systems

    Comprehensive description of clinical characteristics of a large systemic Lupus Erythematosus Cohort from the Spanish Rheumatology Society Lupus Registry (RELESSER) with emphasis on complete versus incomplete lupus differences

    No full text
    Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by multiple organ involvement and pronounced racial and ethnic heterogeneity. The aims of the present work were (1) to describe the cumulative clinical characteristics of those patients included in the Spanish Rheumatology Society SLE Registry (RELESSER), focusing on the differences between patients who fulfilled the 1997 ACR-SLE criteria versus those with less than 4 criteria (hereafter designated as incomplete SLE (iSLE)) and (2) to compare SLE patient characteristics with those documented in other multicentric SLE registries. RELESSER is a multicenter hospital-based registry, with a collection of data from a large, representative sample of adult patients with SLE (1997 ACR criteria) seen at Spanish rheumatology departments. The registry includes demographic data, comprehensive descriptions of clinical manifestations, as well as information about disease activity and severity, cumulative damage, comorbidities, treatments and mortality, using variables with highly standardized definitions. A total of 4.024 SLE patients (91% with ≄4 ACR criteria) were included. Ninety percent were women with a mean age at diagnosis of 35.4 years and a median duration of disease of 11.0 years. As expected, most SLE manifestations were more frequent in SLE patients than in iSLE ones and every one of the ACR criteria was also associated with SLE condition; this was particularly true of malar rash, oral ulcers and renal disorder. The analysis-adjusted by gender, age at diagnosis, and disease duration-revealed that higher disease activity, damage and SLE severity index are associated with SLE [OR: 1.14; 95% CI: 1.08-1.20 (P < 0.001); 1.29; 95% CI: 1.15-1.44 (P < 0.001); and 2.10; 95% CI: 1.83-2.42 (P < 0.001), respectively]. These results support the hypothesis that iSLE behaves as a relative stable and mild disease. SLE patients from the RELESSER register do not appear to differ substantially from other Caucasian populations and although activity [median SELENA-SLEDA: 2 (IQ: 0-4)], damage [median SLICC/ACR/DI: 1 (IQ: 0-2)], and severity [median KATZ index: 2 (IQ: 1-3)] scores were low, 1 of every 4 deaths was due to SLE activity. RELESSER represents the largest European SLE registry established to date, providing comprehensive, reliable and updated information on SLE in the southern European population
    corecore