Symmetry-breaking in a generalized Wirtinger inequality

The search of the optimal constant for a generalized Wirtinger inequality in an interval consists in minimizing the $p$-norm of the derivative among all functions whose $q$-norm is equal to~1 and whose $(r-1)$-power has zero average. Symmetry properties of minimizers have attracted great attention in mathematical literature in the last decades, leading to a precise characterization of symmetry and asymmetry regions. In this paper we provide a proof of the symmetry result without computer assisted steps, and a proof of the asymmetry result which works as well for local minimizers. As a consequence, we have now a full elementary description of symmetry and asymmetry cases, both for global and for local minima. Proofs rely on appropriate nonlinear variable changes.Comment: 17 page

Temperature dependence of oxidation kinetics of extra virgin olive oil (EVOO) and shelf-life prediction

Producers have to guarantee the extra virgin olive oil (EVOO) quality characteristics reported in the Regulation (CEE) 2568/91 throughout the product shelf-life (SL). Unfortunately, due to the development of oxidative reactions, some quality indices change during storage leading to a progressive deterioration of EVOO quality. To avoid the risk of product downgrading in the virgin oil category, the development of effective shelf-life prediction models is extremely important for the olive oil industry. In this research, the accelerated shelf-life testing (ASLT) protocol was applied to evaluate the temperature dependence of selected oxidation indexes as well as to develop a shelf-life predictive model. The evolution of conventional (peroxide value, K232, K270, polyphenols, tocopherols and hexanal) and unconventional parameters (conjugated trienes and pyropheophytin a) was monitored in bottled EVOO stored in the dark at increasing temperature (25, 40, 50 and 60 \ub0C). Accordingly, for well-packed products with reduced oxygen in headspace, the best shelf-life index allowing the ability to predict EVOO SL turned out to be K270. In addition, pyropheophytin a (%) has been shown to be more sensitive to temperature changes than the secondary oxidation indices, thus suggesting its use as a freshness indicator for storage temperatures higher than 25 \ub0C

Parámetros químicos y actividad antioxidante de aceitunas de mesa al estilo natural de color cambiante de la variedad Sigoise

A chemical characterization of turning color table olives of the Sigoise variety was made through their processing as natural-style. Polyphenols, sugars, tocopherols, fatty acids, and antioxidant activity in the olives were monitored throughout the elaboration process. Oleuropein, salidroside, hydroxytyrosol 4-glucoside, rutin, ligustroside and verbascoside showed a decrease of 16.90-83.34%, while hydroxytyrosol increased during the first months of brining. Glucose was consumed by 90% due to the metabolism of the fermentative microbiota. The tocopherol content remained stable during the process and only the α-tocopherol decreased. The fatty acids were not affected. The loss in antioxidant compounds resulted in a decrease in the percentage of DPPH radical inhibition from 75.91% in the raw fruit to 44.20% after 150 days of brining. Therefore, the turning color natural table olives of the Sigoise variety are a good source of bioactive compounds.La caracterización química de las aceitunas en salmuera de color cambiante de la variedad Sigoise se ha estudiado durante el proceso de elaboración, en particular la concentración de fenoles, azúcares, tocoferoles, ácidos grasos y la actividad antioxidante. La concentración de oleuropeína, salidrósido, hidroxitirosol 4-glucósido, rutina, ligustrósido y verbascósido disminuyó un 16,90-83,34% durante el primer mes en salmuera. El 90% de la glucosa fue consumida debido al metabolismo de la microbiota fermentativa. El contenido en tocoferoles se mantuvo constante durante el proceso y solo disminuyó el α-tocoferol. Los ácidos grasos no se vieron afectados. La pérdida de actividad antioxidante se tradujo en una disminución del porcentaje de inhibición del radical DPPH de un 75,91% del fruto fresco a 44,20% después de 150 días en salmuera. A pesar de todo, la aceituna color cambiante de la variedad Sigoise en salmuera es una buena fuente de compuestos bioactivos

Phenolic compounds and fatty acids content of some West Algerian olive oils

Olive represents the most widespread fruit cultivated in Algeria. Olive oil is the primary source of added fat in the Mediterranean diet with health benefits of which have been verified for millennia. Interest in phenolic compounds in olive oil has increased due to its antioxidant activity, which plays a very important role in human health. The present study is carried out to study the phenolic compounds and fatty acids profile of some olive oils from western Algeria. The quality parameters (acidity, peroxide value, K232, K270), tocopherol analysis, fatty acid composition and phenolic profile were determined by High performance chromatography (HPLC). The results showed that chemlal oil (SBA) recorded the highest level of tocopherol-α with 228.12 mg/Kg. Regarding the fatty acid composition, oleic acid was the most dominant, oil Oleaster (Bensekrane) records the highest percentage (72.80%) of oleic acid. The quantitative data on the phenolic content of the seven samples revealed that chemlal oil (SBA) had the highest level of polyphenols (328.99 mg/Kg). However, Sigoise oil (Sebra1) was characterized by the highest levels of tyrosol and hydroxytyrosol (15.89 mg/kg and 22.42 mg/kg, respectively). The highest concentrations of oleuropein derivatives and ligstroside derivatives were observed in chemlal oil (SBA) and the recoreded values were 105.97 mg/Kg and 83.49 mg/Kg, respectively. Chemlal oil (SBA) was characterized by the highest amount of lignans (35.93 mg/Kg), luteolin (10.16 mg/Kg) and apigenin (5.44 mg/Kg). Oleocanthal was found in all the tested samples and it was higher in Chemlal oil (102.43 mg/kg).Olive represents the most widespread fruit cultivated in Algeria. Olive oil is the primary source of added fat in the Mediterranean diet with health benefits of which have been verified for millennia. Interest in phenolic compounds in olive oil has increased due to its antioxidant activity, which plays a very important role in human health. The present study is carried out to study the phenolic compounds and fatty acids profile of some olive oils from western Algeria. The quality parameters (acidity, peroxide value, K232, K270), tocopherol analysis, fatty acid composition and phenolic profile were determined by High performance chromatography (HPLC). The results showed that chemlal oil (SBA) recorded the highest level of tocopherol-α with 228.12 mg/Kg. Regarding the fatty acid composition, oleic acid was the most dominant, oil Oleaster (Bensekrane) records the highest percentage (72.80%) of oleic acid. The quantitative data on the phenolic content of the seven samples revealed that chemlal oil (SBA) had the highest level of polyphenols (328.99 mg/Kg). However, Sigoise oil (Sebra1) was characterized by the highest levels of tyrosol and hydroxytyrosol (15.89 mg/kg and 22.42 mg/kg, respectively). The highest concentrations of oleuropein derivatives and ligstroside derivatives were observed in chemlal oil (SBA) and the recoreded values were 105.97 mg/Kg and 83.49 mg/Kg, respectively. Chemlal oil (SBA) was characterized by the highest amount of lignans (35.93 mg/Kg), luteolin (10.16 mg/Kg) and apigenin (5.44 mg/Kg). Oleocanthal was found in all the tested samples and it was higher in Chemlal oil (102.43 mg/kg)

Guaraná - Paullinia cupana, (H.B.K): Estudo da oxidação das formas em pó e em bastões defumados

The guaraná, Paullinia cupana, HBK – is the fruit of the guarana plant, and is native to the Amazon region. It grown in particular in the communities of Maués. Currently production is spread throughout the states of Bahia, Pará, and Mato Grosso. The ripe fruits are collected and placed in containers where water is added to facilitate the separation of the pulp that covers the seeds. After this treatment they are placed in the sun for drying. Then after they are transferred into a frying pan of metal or brick kilns heated with firewood to complete the hassle/roasting. Guaraná is marketed in the form of seeds, powder and smoked sticks. In folk medicine it is used in powder for the following properties: a dietary food, stimulating organic, for the presence of caffeine, analgesic, antipyretic, anti-fermentation, diuretic, antioxidant, and vascular tonic and considered the elixir of life. In the food industry, it is used in the preparation of extracts, syrups, and soft drinks. Lately the consumption of guaraná has had a significant increase in both Brazil and abroad. The evaluation of the oxidation of foods that contain oils and fats is a parameter needed in quality and stability evaluation in order to ensure food safety. The chemical structure of guaraná is mostly unsaturated therefore susceptible to oxidation. Considering the lack of data in the literature refering to secondary oxidation of foodstuffs, the objective of this work was to evaluate the total content of fatty acids oxidized in the form of guaraná powder and stick. The determination was performed by HPLC-UV. The results of the analysis of oxidation of the powder samples and sticks are different depending on the time of collection, preparation mode and preservation system. We propose new research with ripe fruits selected and processed in place to make it possible to decrease the oxidative status.O guaraná - Paullinia cupana, HBK - fruto do guaranazeiro - é uma planta nativa da região Amazônica. No Amazonas é cultivado, principalmente, em Maués. Atualmente, a produção se estende pelos Estados da Bahia, Pará e Mato Grosso. Os frutos maduros são colhidos e reunidos em recipientes onde é adicionado água para facilitar a separação da polpa que revestem as sementes/ramas. Após esse tratamento, são levadas ao sol para pré-secagem. A seguir são transferidas para tachos de metal ou em fornos de barro aquecidos com fogo a lenha, para completar a secagem/torrefação. É comercializado nas formas de pó, sementes e bastões defumados. Na medicina popular é utilizado em pó, com os seguintes atributos: dietético alimentar, estimulante orgânico devido a presença de cafeína, analgésico, antipirético, antifermentativo, diurético, antioxidante, tônico vascular (antiateromas) e considerado elixir de longa vida. Na indústria de alimentos, é empregado nas preparações de extratos, xaropes e bebidas refrigerantes. Ultimamente, o consumo de guaraná teve um importante aumento, tanto no Brasil quanto no exterior. O processo de oxidação em alimentos contendo óleos e gorduras é um parâmetro indispensável na qualidade e estabilidade do produto a fim de garantir a segurança alimentar. A estrutura química do guaraná é predominantemente insaturada, portanto, suscetível à oxidação. Considerando a escassez de dados na literatura a respeito da oxidação secundária de gêneros alimentícios, o objetivo deste trabalho foi avaliar o teor de ácidos graxos oxidados totais de guaraná em pó e em bastão defumado de procedências, safras, modo de preparação e sistema de conservação diferentes. A determinação foi feita por meio de Cromatografia Líquida de Alta Eficiência (CLAE-UV). Os resultados das análises de oxidação das amostras em pó e em bastão, divergem entre si, em decorrência da safra, modo de preparação e sistema de conservação. Propomos novas investigações com frutos maduros selecionados e processamentos adequados para possibilitar a diminuição do estado oxidativo

Antioxidant and Anti-Inflammatory Effect of Cinnamon (Cinnamomum verum J. Presl) Bark Extract after In Vitro Digestion Simulation

Cinnamon bark is widely used for its organoleptic features in the food context and growing evidence supports its beneficial effect on human health. The market offers an increasingly wide range of food products and supplements enriched with cinnamon extracts which are eliciting beneficial and health-promoting properties. Specifically, the extract of Cinnamomum spp. is rich in antioxidant, anti-inflammatory and anticancer biomolecules. These include widely reported cinnamic acid and some phenolic compounds, such asproanthocyanidins A and B, and kaempferol. These molecules are sensitive to physical-chemical properties (such as pH and temperature) and biological agents that act during gastric digestion, which could impair molecules' bioactivity. Therefore, in this study, the cinnamon's antioxidant and anti-inflammatory bioactivity after simulated digestion was evaluated by analyzing the chemical profile of the pure extract and digested one, as well as the cellular effect in vitro models, such as Caco2 and intestinal barrier. The results showed that the digestive process reduces the total content of polyphenols, especially tannins, while preserving other bioactive compounds such as cinnamic acid. At the functional level, the digested extract maintains an antioxidant and anti-inflammatory effect at the cellular level

Helmet CPAP treatment in patients with COVID-19 pneumonia: a multicenter, cohort study

Helmet CPAP treatment fails in up to 44% of patients with moderate-to-severe hypoxemic acute respiratory failure due to COVID-19 pneumoni

Climate change alterations to ecosystem dominance: how might sponge-dominated reefs function?

Anthropogenic stressors are impacting ecological systems across the world. Of particular concern are the recent rapid changes occurring in coral reef systems. With ongoing degradation from both local and global stressors, future reefs are likely to function differently to current coral-dominated ecosystems. Determining key attributes of future reef states is critical to reliably predict outcomes for ecosystem service provision. Here we explore the impacts of changing sponge dominance on coral reefs. Qualitative modelling of reef futures suggests that changing sponge dominance due to increased sponge abundance will have different outcomes for other trophic levels compared with increased sponge dominance as a result of declining coral abundance. By exploring uncertainty in the model outcomes we identify the need to: i) quantify changes in carbon flow through sponges, ii) determine the importance of food limitation for sponges, iii) assess the ubiquity of the recently described 'sponge loop', iv) determine the competitive relationships between sponges and other benthic taxa, particularly algae, and v) understand how changing dominance of other organisms alters trophic pathways and energy flows through ecosystems. Addressing these knowledge gaps will facilitate development of more complex models that assess functional attributes of sponge-dominated reef ecosystems. This article is protected by copyright. All rights reserved

Phenolic Molecules in Virgin Olive Oils: a Survey of Their Sensory Properties, Health Effects, Antioxidant Activity and Analytical Methods. An Overview of the Last Decade Alessandra

Among vegetable oils, virgin olive oil (VOO) has nutritional and sensory characteristics that to make it unique and a basic component of the Mediterranean diet. The importance of VOO is mainly attributed both to its high content of oleic acid a balanced contribution quantity of polyunsaturated fatty acids and its richness in phenolic compounds, which act as natural antioxidants and may contribute to the prevention of several human diseases. The polar phenolic compounds of VOO belong to different classes: phenolic acids, phenyl ethyl alcohols, hydroxy-isochromans, flavonoids, lignans and secoiridoids. This latter family of compounds is characteristic of Oleaceae plants and secoiridoids are the main compounds of the phenolic fraction. Many agronomical and technological factors can affect the presence of phenols in VOO. Its shelf life is higher than other vegetable oils, mainly due to the presence of phenolic molecules having a catechol group, such as hydroxytyrosol and its secoiridoid derivatives. Several assays have been used to establish the antioxidant activity of these isolated phenolic compounds. Typical sensory gustative properties of VOO, such as bitterness and pungency, have been attributed to secoiridoid molecules. Considering the importance of the phenolic fraction of VOO, high performance analytical methods have been developed to characterize its complex phenolic pattern. The aim of this review is to realize a survey on phenolic compounds of virgin olive oils bearing in mind their chemical-analytical, healthy and sensory aspects. In particular, starting from the basic studies, the results of researches developed in the last ten years will be focused