1,613 research outputs found

    Robust Stability and Optimality Conditions for Parametric Infinite and Semi-Infinite Programs

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    This paper primarily concerns the study of parametric problems of infinite and semi-infinite programming, where functional constraints are given by systems of infinitely many linear inequalities indexed by an arbitrary set T, where decision variables run over Banach (infinite programming) or finite-dimensional (semi-infinite case) spaces, and where objectives are generally described by nonsmooth and nonconvex cost functions. The parameter space of admissible perturbations in such problems is formed by all bounded functions on T equipped with the standard supremum norm. Unless the index set T is finite, this space is intrinsically infinite-dimensional (nonreflexive and nonseparable) of the l(infinity)-type. By using advanced tools of variational analysis and generalized differentiation and largely exploiting underlying specific features of linear infinite constraints, we establish complete characterizations of robust Lipschitzian stability (with computing the exact bound of Lipschitzian moduli) for parametric maps of feasible solutions governed by linear infinite inequality systems and then derive verifiable necessary optimality conditions for the infinite and semi-infinite programs under consideration expressed in terms of their initial data. A crucial part of our analysis addresses the precise computation of coderivatives and their norms for infinite systems of parametric linear inequalities in general Banach spaces of decision variables. The results obtained are new in both frameworks of infinite and semi-infinite programming

    Variational Analysis in Semi-Infinite and Infinite Programming, II: Necessary Optimality Conditions

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    This paper concerns applications of advanced techniques of variational analysis and generalized differentiation to problems of semi-infinite and infinite programming with feasible solution sets defined by parameterized systems of infinitely many linear inequalities of the type intensively studied in the preceding development [5] from our viewpoint of robust Lipschitzian stability. We present meaningful interpretations and practical examples of such models. The main results establish necessary optimality conditions for a broad class of semi-infinite and infinite programs, where objectives are generally described by nonsmooth and nonconvex functions on Banach spaces and where infinite constraint inequality systems are indexed by arbitrary sets. The results obtained are new in both smooth and nonsmooth settings of semi-infinite and infinite programming

    Tourist events and satisfaction: a product of regional tourism competitiveness

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    Purpose – This study aims to analyze the contribution of tourist event and satisfaction with tourism events as a product of regional tourism competitiveness, as well as evaluate factors of competitiveness. Design/methodology/approach – The research followed a quantitative methodology by conducting a questionnaire on the four largest tourist events in Madeira (Carnival, Flower Festival, Atlantic Festival and Wine Festival), an insular island located in Portugal. Findings – The sample consisted of 2,262 tourists surveyed during the year 2017 and structural equation models were used as the statistical method. Results showed that satisfaction is reflected in the client’s loyalty to the choice of a tourist destination and also contributes directly and indirectly to the regional tourist competitiveness. Originality/value – This study contributes to the valorization of local and regional events, perceived by the level of satisfaction and loyalty of tourists, as products of regional competitiveness of a tourist destination.info:eu-repo/semantics/publishedVersio

    Social engagement within the facility increased life expectancy in nursing home residents [preprint]

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    Conjunto de datos disponible en: http://hdl.handle.net/20.500.12105/11202 y Artículo final en: https://repisalud.isciii.es/handle/20.500.12105/11382Social engagement (SE) has been consistently shown to improve survival among community- dwelling older people, but the evidence in nursing home residents is inconclusive and prone to short-term reverse causation and confounding by major health determinants. A representative cohort of 382 nursing home residents in Madrid without severe physical and cognitive impairments at baseline was followed up for 10-year all-cause mortality. Standardized cumulative mortality curves for residents with low/null, moderate, and high levels of SE at baseline were estimated using Kaplan-Meier methods and spline-based survival models with inverse probability of exposure weights conditional on baseline sociodemographic characteristics, facility features, comorbidity, and disability. Standardized 5-year mortality risks and median survival times were compared across levels of SE. The baseline prevalences of low/null, moderate, and high SE were 36.0%, 44.2%, and 19.8%, respectively. A total of 268 residents died during 2,305 person-years of follow-up. Compared with residents with low/null SE at baseline, the standardized differences (95% confidence intervals) in 5-year mortality risk were −2.3% (−14.6% to 10.0%) for moderately engaged residents and −18.4% (−33.8% to −2.9%) for highly engaged residents. The median survival time increased by 0.4 (−1.4 to 2.2) and 3.0 (0.8 to 5.2) years, respectively. Residents with high SE within the nursing home had substantially lower mortality risk and longer median survival than residents with similar health determinants but low/null SE. The development of intervention programs, aimed at increasing SE among nursing home residents, could improve their long-term survival with an inherent gain in quality of life.This work was supported by the Institute of Health Carlos III (Grant PI15CIII00037). The funding agencies had no role in study design, data analysis, interpretation of results, manuscript preparation, or in the decision to submit this manuscript for publicationN

    Hidrogenionic potential (pH) of the attractant, trap density and control threshold for Ceratitis capitata (Diptera: tephritidae) on Hamlin oranges in São Paulo central region, Brazil

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    This study evaluated the effect of initial pH values of 4.5, 6.5 and 8.5 of the attractant (protein bait) Milhocina® and borax (sodium borate) in the feld, on the capture of fruit flies in McPhail traps, using 1, 2, 4 and 8 traps per hectare, in order to estimate control thresholds in a Hamlin orange grove in the central region of the state of São Paulo. The most abundant fruit fly species was Ceratitis capitata, comprising almost 99% of the fruit flies captured, of which 80% were females. The largest captures of C. capitata were found in traps baited with Milhocina® and borax at pH 8.5. Captures per trap for the four densities were similar, indicating that the population can be estimated with one trap per hectare in areas with high populations. It was found positive relationships between captures of C. capitata and the number of Hamlin oranges damaged, 2 and 3 weeks after capture. It was obtained equations that correlate captures and damage levels which can be used to estimate control thresholds. The average loss caused in Hamlin orange fruits by C. capitata was 2.5 tons per hectare or 7.5% of production.Esta pesquisa teve como objetivos: avaliar o efeito do pH inicial, 4.5; 6.5 e 8.5, do atrativo proteico Milhocina® e bórax (tetraborato de sódio) na captura de moscas-das-frutas em armadilhas McPhail; estudar densidades de armadilhas, 1; 2; 4 e 8 por hectare, para estimar níveis de controle em laranja cv. Hamlin, na região central de São Paulo. A espécie predominante, com 99% das moscas-das-frutas capturadas, foi Ceratitis capitata, sendo 80% de fêmeas. As maiores capturas de C. capitata ocorreram nas armadilhas com Milhocina® e bórax em pH 8.5. As capturas, nas 4 densidades, foram semelhantes, indicando que a população pode ser estimada com uma armadilha por hectare em áreas de altas populações. Houve relações positivas entre capturas de C. capitata e o número de frutos danificados, 2 e 3 semanas após a captura. Assim, foram obtidas equações que relacionam a captura e o dano, possibilitando estimar níveis de controle desse inseto. As perdas médias causadas por C. capitata em laranja cv. Hamlin chegaram a 2,5 toneladas de frutos por hectare ou 7,5% da produção.info:eu-repo/semantics/publishedVersio

    Floraciones de fitoplancton y variación de la estructura comunitaria fitoplanctónica en tres lagos someros eutróficos de Chile Central

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    The phytoplankton community of three eutrophic shallow lakes located in the same geographical area was compared over a period of three years. Although these lakes are similar in many respects (e.g. location, origin, average depth, high concentration of nutrients, human influence) develop very different phytoplankton communities. Lo Galindo is dominated by Zygnematophyceae, Cyanophyceae and Chlorophyceae, while in Lo Méndez the groups Dinophyceae and Bacillariophyceae and in Las Tres Pascualas the Chlorophyceae, Cryptophyceae and Euglenophyceae. In Lo Mendez and Lo Galindo are frequent blooms of different groups of algae (cyanobacteria, green algae, diatoms and dinoflagellates), which generated wealth increases at different times of the year, even in winter they were presented. In Las Tres Pascualas blooms were rare. The occurrence and frequency of blooms of species representatives of the M, C,Y and Lo functional groups, and VII, VI, IV and V morphological groups, reflect the eutrophic lakes, being indicative of the degree of contamination of these systems that influence their present and future use.La comunidad fitoplanctónica de tres lagos someros eutróficos ubicados en la misma zona geográfica fue comparada durante un periodo de tres años. Aunque estos lagos son similares en muchos aspectos (p.ej. ubicación, origen, profundidad media, alta concentración de nutrientes, influencia humana) desarrollan comunidades de fitoplancton muy diferentes. En Lo Galindo dominan Zygnematophyceae, Cyanophyceae y Chlorophyceae, en Lo Méndez Dinophyceae y Bacillariophyceae y en Las Tres Pascualas Chlorophyceae, Cryptophyceae y Euglenophyceae. En Lo Méndez y Lo Galindo se presentaron frecuentes floraciones de diferentes grupos de microalgas (cianobacterias, algas verdes, diatomeas y dinoflagelados), las que generaron aumentos de abundancia en diferentes épocas del año, incluso en invierno. En Las Tres Pascualas, las floraciones fueron poco frecuentes. La ocurrencia y frecuencia de floraciones de especies representantes de los grupos funcionales M, C, Y y Lo y morfológicos VII, VI, IV y V reflejan las condiciones eutróficas de los lagos, siendo indicadoras del grado de contaminación de estos sistemas que influencia su uso actual y futuro

    Addressing the high cervical cancer rates along the Texas-Mexico border through community outreach, patient navigation, and provider training/telementoring

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    Objective: Cervical cancer incidence and mortality rates are 68% and 57% higher, respectively, along the Texas-Mexico border compared with the rest of the United States. This is likely due to a combination of low health literacy, limited access to affordable screening, and a lack of trained personnel to perform colposcopy, loop electrosurgical excision procedures (LEEP), and appropriate management of women with pre-invasive disease. The objective of our study was to increase cervical cancer screening, diagnosis, and treatment rates in the Rio Grande Valley (RGV). Method: We initiated a comprehensive program at two health centers and one mobile clinic in the RGV consisting of (1) a public education program designed for community health workers to teach women about cervical cancer screening and HPV vaccination coupled with patient navigation to participating clinics; (2) colposcopy and LEEP training for physicians and advanced-practice providers through locally held hands-on courses and mentoring program; and (3) implementation of Project ECHO (Extension for Community Health Outcomes), a well-established telementoring program using video conferencing to connect academic specialists with community providers for case-based learning. We compared screening, diagnosis, and treatment rates pre- and post-program implementation. Results: From November 2014 to June 2018, local providers screened 19,028 women with Pap ± HPV testing (baseline 12,460, 53% increase); performed colposcopy on 2,644 women with abnormal screening results (baseline 945, 180% increase); and performed 483 LEEP procedures for treatment of cervical dysplasia (baseline 0). Ten women were diagnosed with invasive cancer and navigated to one of the participating gynecologic oncologists for treatment (baseline N/A). Five additional providers in the RGV completed the mentoring program to be certified to perform colposcopy (100% increase from baseline of 5) and two additional providers to perform LEEP (baseline 0). ECHO telementoring video conferences have been held every two weeks for a total 94 sessions (average of 22 participants/session) with 182 patient cases presented and discussed. Conclusion: Our comprehensive approach has led to an increase in the number of women undergoing cervical cancer screening and diagnosis/treatment of dysplasia. If sustained, we anticipate these efforts will decrease cervical cancer rates in the RGV. The program is currently being expanded to additional medically underserved regions of Texas
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