Hopf and zip bifurcation in a specific (n+1)-dimensional competitive system

In this work we study the occurrence of Andronov-Hopf and zip bifurcation in a concrete (n + 1)-dimensional predator-prey system modelling the competition among n species of predators for one species of prey. This is a generalization of results by Farkas (1984

Glass waste powder addition used as mitigator of concrete alkali-silica reaction

The recycled aggregates from demolition of concrete structures affected by alkali silica reaction as well as the potentially reactive natural aggregates are often a matter of great concern and fear in case of new structures construction. Thus, to encourage the recycling and use of some potential reactive aggregates under scientific basis, this paper presents an experimental study where suspected alkali-silica reactive recycled aggregates was used. The main goal of this study is evaluate the influence of waste glass powder addition as mitigator of the concrete expansive reaction. In a first phase, the level of expansibility of different aggregates was identified using accelerated tests in mortars bars, method ASTM C1260 and an adapted accelerated test on specimens of 40 x 40 x 160 mm. In a second phase, tests were performed on concrete mixtures, according to CMBT method, with 100% recycled reactive coarse aggregates and powder addition, such as the glass powder and metakaolin. The powder additions percentages were incorporated at 20%, 40% and 60% of cement weight. The results of mortars bars test showed opposite results according to the method applied, i.e. , the same aggregates considered as harmless by the adapted method are considered reactive by the ASTM method, if the same expansion limit of 0,10% for 16 days was adopted for both methods. Finally, the concrete results obtained with CMBT method showed that glass powder and metakaolin had a significant mitigation effect in alkali-aggregate reaction development

High prevalence of HIV-associated neurocognitive disorders (HAND) in São Paulo City, Brazil

Introduction: HIV-associated neurocognitive disorders (HAND) are the subject of many studies, some of them reporting a prevalence of up to 50 percent. Objectives: To determine the prevalence and factors associated with HIV neurocognitive disorders (HAND) in a cohort of HIV-1-infected patients in São Paulo city, Brazil. Methodology: Descriptive cross-sectional study including 106 HIV-1-infected patients, employing direct interview and neuropsychological tests, applied by trained neuro-psychologists with expertise in the tests. Other, similar assessment tools we used were Brief Neurocognitive Questionnaire, International HIV Dementia Scale, Lawton Instrumental Activities of Daily Living, Hospital Anxiety and Depression Scale, Social Support Scale for People with HIV/Aids, Assessment of Adherence to Antiretroviral Therapy Questionnaire, and a complex neuropsychological assessment. Results: We included 106 patients from May 2015 to April 2018. We found a high prevalence of HAND in our patients (45%), with 27.5% presenting asymptomatic neurological impairment (ANI) and 17.5% mild neurological dysfunction (MND); only one patient presented HIV-associated dementia (HAD) (0.9%). Women were more likely to have MND (52.9%) and the only case of HAD was also female. The high prevalence of neurocognitive disorders was independent of the immunological status, use of efavirenz, or virological control. Conclusions: This study may mirror the national and international scenarios, showing a high prevalence of HAND (45%) and the prevalence of some risk factors, in special among women

The inventory of geological heritage of the state of São Paulo, Brazil: Methodological basis, results and perspectives

An inventory of geological sites based on solid and clear criteria is a first step for any geoconservation strategy. This paper describes the method used in the geoheritage inventory of the State of São Paulo, Brazil, and presents its main results. This inventory developed by the geoscientific community aimed to identify geosites with scientific value in the whole state, using a systematic approach. All 142 geosites representative of 11 geological frameworks were characterised and quantitatively evaluated according to their scientific value and risk of degradation, in order to establish priorities for their future management. An online database of the inventory is under construction, which will be available to be easily consulted and updated by the geoscientific community. All data were made available to the State Geological Institute as the backbone for the implementation of a future state geoconservation strategy.The authors acknowledge the Science Without Borders Programme, Process 075/2012, which supported this study and the São Paulo Research Foundation (FAPESP), Process 2011/17261-6. We also thanks C. Mazoca for his help with maps and figures.info:eu-repo/semantics/acceptedVersio