Seasonal Variation of Ectosymbiotic Ciliates on Farmed and Wild Shrimps from Coastal Yucatan, Mexico

High levels of ciliate infestation can affect respiration, feed intake, and locomotion in farmed shrimps in the tropics. Information on seasonal variation of the infestation parameters of ciliates is scarce, but it would be useful for determining the suitability of preventive measures or therapeutic treatment if necessary. This study aimed to describe the prevalence and mean intensity of infestation (MII) of ciliates on wild native shrimps Penaeus (Farfantepenaeus) brasiliensis and P. (Farfantepenaeus) duorarum and farm-cultured juvenile shrimp Penaeus (Litopenaeus) vannamei over an annual cycle and to determine whether an association existed among physicochemical factors and infestation on cultured shrimp. The ectosymbiotic ciliates Acineta tuberosa, Epistylis sp., and Zoothamnium sp. infested both farmed and wild shrimps. Based on examination of 360 farmed specimens of P. vannamei (30 examined each month), the species with highest infestation were Epistylis sp., (prevalence range = 22 –100%; MII range = 13 ± 28 – 126 ± 124) and Zoothamnium sp. (0–87%; 0 – 144 ± 132). For both species, the highest values occurred during the rainy season. A total of 288 wild specimens of P. brasiliensis plus 120 of P. duorarum obtained during three recognized seasons—dry (February to May), rainy (June to September), and north-wind (October to January)—had ciliate infestations that were significantly lower than those from farmed shrimp. For P. brasiliensis, the ciliate species with the highest infestation values were Zoothamnium sp. (0–66%; 0.03 ± 0.2 – 66 ± 92), while on P. duorarum, were for Epistylis sp. (0–46%; 0 – 8 ± 16). Using multiple linear regression, we found significant relationships between stocking density, survival, temperature, turbidity, and intensity of infestation of the ciliates. However, the regression accounted for only 11–26% of the variance (R2), meaning that there are still other environmental and biological variables that should be included to increase the reliability of the model. Thus, the physicochemical conditions of the farm increase the probability of ciliate transmission, especially during the rainy season

A comparative study between single gas and mixed gas permeation of polyether-block-amide type copolymer membranes

We analyze the gas separation performance of five polyether-block-amide type copolymers (Pebax® 1657, Renew®, 2533, 3533 and 4533). These codes are composed of different hard and rubbery segments with different proportions. Dense membranes were prepared by the casting-solution method and studied by elemental, thermogravimetric and X-ray diffraction analyses, FTIR-ATR spectroscopy and single and mixed gas permeation. Codes with the best separation performance are those of polyethylene oxide as the soft phase (Pebax® 1657 and Renew®) due to the more intense interactions of this segment with CO2, which increases the CO2/N2 solubility selectivity (17.5 and 30.5 for Pebax® 1657 and Renew®, respectively) and hence the CO2/N2 separation selectivity of the membrane (36 and 37 for Pebax® 1657 and Renew®, respectively, obtained from mixed gas permeation). It is also noticeable that the proportion of the soft phase in the copolymer determines the permeability of CO2. It was found that the codes with a greater soft/hard segment ratio (Pebax® 2533 and 3533) have also a greater permeability value (239 and 220 Barrer for Pebax® 2533 and 3533, respectively, measured by mixed gas permeation). Pebax® Renew® was the polymer with the best separation performance with CO2 permeabilities of 167 and 164 Barrer and CO2/N2 selectivities of 41 and 37, measured by single and mixed gas permeation, respectively. The comparison between the single and mixture gas permeation results revealed a relatively good correspondence between both for most of the Pebax® codes tuned by the solubility and diffusion properties of the polymers. © 2022 The Authors

Antioxidant activity of isolated compounds in non-volatile residue from orange essential oil

6 páginas, 3 figuras.[ES] Existe un creciente interés en la industria alimentaria y en la medicina preventiva por la búsqueda de «antioxidantes naturales», por lo que nos planteamos evaluar la actividad antioxidante del residuo no volátil del aceite esencial de naranja contra la oxidación del aceite de oliva sin retinar y de reciente extracción. Mediante destilación del aceite esencial de naranja se obtuvo el residuo no-volátil, el cual se fraccionó en columna de silica gel 60. La actividad antioxidante fue medida por el valor de peróxidos producidos por el aceite de oliva al provocar la oxidación por calentamiento a 70 °C durante 48 h. Se aislaron seis compuestos mediante H PLC preparativo de los cuales cuatro tuvieron actividad antioxidante. Usando métodos espectroscópicos se identificaron a-tocoferol y tres flavonas metoxiladas. Con este estudio se confirmó que la fracción no volátil del aceite esencial de naranja contiene antioxidantes naturales diferentes al a-tocoferol.[EN] There has been a growing interest in the food industry and in preventive medicine to search for «natural antioxidants». Therefore the objetive of this study was to evaluate the antioxidant activity of the non-volatile residue of essential orange oil in the oxidation of unrefined and freshly extracted olive oil. Essential orange oil was distilled to obtain a non-volatile residue and fracctionated on a Silica Gel 60 column. The antioxidant activity was determined by measuring peroxide value obtained after heating olive oil at 70 °C for 48 h. Six compounds were isolated and purified, four of these had antioxidant activity, a-tocopherol and three methoxylated flavones were identified using spectroscopic methods. This study confirmed that non-volatile fractions of essential orange oil contain natural antioxidants diferent from a-tocopherol.Peer reviewe

Impact of cow's milk intake on exercise performance and recovery of muscle function: a systematic review

Dairy products are thought to improve recovery after both resistance and endurance exercises due to their nutritional proprieties. We systematically reviewed the effects of dairy product intake on exercise performance and recovery of muscle function in humans. A literature search was conducted in the MEDLINE (via PubMed) and Web of Science databases from their inception to 15th April 2018. The initial search retrieved 7708 articles, and a total of 11 studies were finally included after applying inclusion and exclusion criteria. All the selected studies were conducted with cow's milk. Whereas some studies found significant positive effect of cow's milk on exercise performance and recovery of muscle function, others did not find any effect. These controversies could be due to the heterogeneity of cow's milk ingestion (e.g., amount of cow's milk, timing of consuming the cow's milk), to the type of intervention, and to the large heterogeneity of outcomes measured. Limited studies exist examining the effects of cow's milk consumption and its influence on exercise performance and recovery of muscle function, therefore further studies are needed to draw more definitive conclusions.The study was supported by the Spanish Ministry of Education (FPU 13/04365 and 15/04059), by the Redes temáticas de investigación cooperativa RETIC (Red SAMID RD16/0022), and by the University of Granada Plan Propio de Investigacion 2016 -Excellence actions: Unit of Excellence on Exercise and Health (UCEES) - and Plan Propio de Investigación 2018 - Programa Contratos-Puente, and the Junta de Andalucía, Consejería de Conocimiento, Investigación y Universidades (ERDF: ref. SOMM17/6107/UGR), and by the Interprofessional Dairy Organization (INLAC) of Spain

DEFICIENCIA DE AZUFRE EN SUELOS CULTIVABLES Y SU EFECTO EN LA PRODUCTIVIDAD

En décadas pasadas el azufre fue considerado como un elemento contaminante del ambiente, esto generó que se crearan legislaciones para reducir las emisiones del elemento a la atmósfera, lo cual ocasionó un desbalance en el ciclo global de azufre, llegando a ser insuficiente en suelos donde se practica la agricultura intensiva. China fue el primer país en reconocer el problema y creó un programa de fertilización con azufre. El resultado fue un incremento en la productividad agrícola. La deficiencia de azufre en suelos está relacionada a baja productividad, mayor susceptibilidad a plagas, menor resistencia a sequía, frío y salinidad. Es necesario que cada región agrícola determine los niveles de azufre en suelos de cultivo, donde las medidas correctivas mejorarían la productividad. Según datos de la FAO se necesita incrementar la producción de alimentos en un 60% en las próximas 4 décadas; la fertilización con azufre podría ser un factor a considerar para lograrlo. La tecnología de fertilizantes ha generado una variedad de productos azufrados cuya selección estará en función de las condiciones edafoclimáticas, entre otros factores. Para los suelos deficientes de azufre, es necesario tomar medidas correctivas, dado que la demanda de alimentos es cada vez más grande

Dietary Fluoride Intake Over the Course of Pregnancy in Mexican Women

Objective: To estimate dietary fluoride intake (F) over the course of pregnancy and the overall adjusted difference in dietary F intake by pregnancy stages and levels of compliance with dietary recommendations. Design: Secondary data analysis from a longitudinal pregnancy cohort study in a population exposed to fluoridated salt. Women were followed during the early, middle and late stages of their pregnancy (n 568). The dietary intake of recommended prenatal nutrients according to Mexican dietary guidelines and F intake (mg/d) was estimated with a validated FFQ. Data were summarised with descriptive statistics. Levels of F intake were compared with the USA’s Institute of Medicine adequate intake (AI) of 3 mg/d for pregnancy. Adjusted differences in F intake by pregnancy stages and levels of compliance with recommendations were estimated using random effects models. Setting: Mexico City. Participants: Women participating in the Early Life Exposures in Mexico to ENvironmental Toxicants (ELEMENT) project, from 2001 to 2003. Results: Median dietary F intake throughout pregnancy ranged from 0·64 (interquartile range (IQR) 0·38) in the early to 0·70 (IQR 0·42) in the middle, and 0·72 (IQR 0·44) mg/d in the late stage (0·01 mg F/kg per d). Corresponding adjusted intakes of F were 0·72 (95 % CI 0·70, 0·74), 0·76 (95 % CI 0·74, 0·77) and 0·80 (95 % CI 0·78, 0·82) mg/d. Women who were moderately and highly compliant with Mexican dietary recommendations ingested, on average, 0·04 and 0·14 mg F/d more than non-compliant women (P < 0·005). Conclusions: Dietary F intake was below current AI, was greater with the progression of pregnancy and in women who were moderately and highly compliant with dietary recommendations