1,749 research outputs found
Estimating the prevalence of hunger and food insecurity: The validity of questionnaire-based measures for the identification of households
This study had three objectives: (1) to assess the validity of questionnaire-based measures in identifying households experiencing hunger and food insecurity, (2) to examine the interrelationships of different questionnaire-based measures, and (3) to examine the construction of a continuous food insecurity scale intended to differentiate three levels of food insecurity within households. A 1993 survey of 193 randomly sampled rural households with women and children living at home provided data on demographics, risk factors for food insecurity, Radimer/Cornell, CCHIP, and NHANES III hunger and food insecurity items, coping strategies, fruit and vegetable consumption, disordered eating behaviors, height, weight, dietary recall, and household food-stores inventory. This information was used to develop a definitive criterion measure for hunger and food insecurity, against which the Radimer/Cornell and CCHIP questionnaire-based measures, the NHANES III item, and the continuous food insecurity scale were tested for their specificity and sensitivity in measuring levels of food insecurity.
Hydrolysable Tannins and Biological Activities of Meriania hernandoi and Meriania nobilis (Melastomataceae)
A bio-guided study of leaf extracts allowed the isolation of two new macrobicyclic
hydrolysable tannins, namely merianin A (1) and merianin B (2), and oct-1-en-3-yl
b-xylopyranosyl-(1”-6’)-b-glucopyranoside (3) from Meriania hernandoi, in addition to 11 known
compounds reported for the first time in the Meriania genus. The structures were elucidated by
spectroscopic analyses including one- and two-dimensional NMR techniques and mass spectrometry.
The bioactivities of the compounds were determined by measuring the DPPH radical scavenging
activity and by carrying out antioxidant power assays (FRAP), etiolated wheat coleoptile assays
and phytotoxicity assays on the standard target species Lycopersicum esculentum W. (tomato).
Compounds 1 and 2 exhibited the best free radical scavenging activities, with FRS50 values of
2.0 and 1.9 M, respectively
Global Antifungal Profile Optimization of Chlorophenyl Derivatives against Botrytis cinerea and Colletotrichum gloeosporioides
Twenty-two aromatic derivatives bearing a chlorine atom and a different chain in the para or meta
position were prepared and evaluated for their in vitro antifungal activity against the phytopathogenic
fungi Botrytis cinerea and Colletotrichum gloeosporioides. The results showed that maximum inhibition
of the growth of these fungi was exhibited for enantiomers S and R of 1-(40-chlorophenyl)-
2-phenylethanol (3 and 4). Furthermore, their antifungal activity showed a clear structure-activity
relationship (SAR) trend confirming the importance of the benzyl hydroxyl group in the inhibitory
mechanism of the compounds studied. Additionally, a multiobjective optimization study of the
global antifungal profile of chlorophenyl derivatives was conducted in order to establish a rational
strategy for the filtering of new fungicide candidates from combinatorial libraries. The MOOPDESIRE
methodology was used for this purpose providing reliable ranking models that can be
used later
Etología. Introducción a la ciencia del comportamiento
1ª ed., 3ª reimp.El objetivo de este libro es proporcionar una introducción a la Etología. Ésta ciencia responde al interés por profundizar en el conocimiento de las costumbres animales; por comprender la variedad de comportamientos que en diferentes situaciones exhiben los individuos de diferentes especies. Una posible definición de Etología podría ser: el estudio científico del comportamiento de los seres vivos. A lo largo de esta obra se analizan todos los aspectos que tienen que ver con el comportamiento animal, desde las causas y mecanismos de actuación o la adaptación y evolución y el bienestar animal.The purpose of this book is to provide an introduction to Ethology. This science responds to the interest in deepening the knowledge of animal customs; to understand the variety of behaviour that in different situations exhibit individuals of different species. A possible definition of ethology could be: the scientific study of the behavior of living beings. Throughout this book all aspects related to animal behavior, from the causes and mechanisms of action or adaptation and evolution and animal welfare, are analyzed
Emissions control investment policy for the 2020 sulphur cap implemented by Port of Gothenburg as a model for the Port of Mombasa
Sistemas prototipos para la micropropagación por inmersión temporal.
El desarrollo de los sistemas de inmersión temporal ha permitido el empleo de medio líquido sin efectos colaterales como la vitrificación. Sin embargo el elevado costo de los recipientes comerciales para inmersión temporal automatizada (RITA) ha impedido su uso en países en desarrollo. En esta investigación se construyó un prototipo para inmersión temporal con insumos nacionales e importados. Este prototipo fue construido con dos frascos de vidrio de boca ancha (500 g) con tapas de plástico horadadas con dos orificios donde se colocan un par de conexiones plásticas de polipropileno de ¼ pulgada con tuercas y empacaduras de goma. Una conexión se usa para la recirculación del medio de cultivo entre los frascos y la otra para la entrada de aire esterilizado por filtración a través de un filtro de goma espuma. El objetivo de esta investigación fue evaluar el funcionamiento de los prototipos para el cultivo in vitro por inmersión temporal usando como modelo, la inducción de yemas axilares en Musa AAA cv. Williams, comparándolos con los RITA. Los microcormos fueron cultivados en un medio líquido compuesto por sales de M&S y vitaminas de Morel, suplementado con 2,5 mg/L de N6-benciladenina, en luz continua (30mM/m2s), con una tiempo de inmersión de 2 minutos cada 6 horas. El índice de multipli- cación que se logró en los RITA fue 6,6 mientras que para los prototipos fue de 5,8, no encontrando diferencias significativas usando las pruebas no parámetricas de Kurskal Wallis y paramétrica de Tukey (p= 0,05 y 0,01). La mayor diferencia radica en que el costo de los prototipos es 1/4 de los RITA, son fáciles de mantener y pueden escalarse con facilidad
Trading or coercion? Variation in male mating strategies between two communities of East African chimpanzees
Across taxa, males employ a variety of mating strategies, including sexual coercion and the provision, or trading, of resources. Biological Market theory (BMT) predicts that trading of commodities for mating opportunities should exist only when males cannot monopolise access to females and/or obtain mating by force, in situations where power differentials between males are low; both coercion and trading have been reported for chimpanzees (Pan troglodytes). Here, we investigate whether the choice of strategy depends on the variation in male power differentials, using data from two wild communities of East African chimpanzees (P.t. schweinfurthii): the structurally despotic Sonso community (Budongo, Uganda) and the structurally egalitarian M-group (Mahale, Tanzania). We found evidence of sexual coercion by male Sonso chimpanzees, and of trading—of grooming for mating—by M-group males; females traded sex for neither meat nor protection from male aggression. Our results suggest that the despotism–egalitarian axis influences strategy choice: male chimpanzees appear to pursue sexual coercion when power differentials are large and trading when power differentials are small and coercion consequently ineffective. Our findings demonstrate that trading and coercive strategies are not restricted to particular chimpanzee subspecies; instead, their occurrence is consistent with BMT predictions. Our study raises interesting, and as yet unanswered, questions regarding female chimpanzees’ willingness to trade sex for grooming, if doing so represents a compromise to their fundamentally promiscuous mating strategy. It highlights the importance of within-species cross-group comparisons and the need for further study of the relationship between mating strategy and dominance steepness
The use of zooplankton metrics to determine the trophic status and ecological potential: An approach in a large Mediterranean watershed.
In the European Water Framework Directive, zooplankton was not included as a Biological Quality Element despite its important place in the aquatic trophic web. In the present study on zooplankton abundances and biomasses, we used several metrics to test their ability to detect differences among trophic statuses and ecological potential levels, and collected a large sum of data in more than 60 reservoirs at Ebro watershed, on more than 300 sampling occasions over 10 years. Our results indicate that most zooplankton metrics are correlated to environmental variables that determine reservoirs' trophic states, especially chlorophyll a and total phosphorus. The metrics with better sensitivity to differentiate trophic states and ecological potential levels were ZOO (total zooplankton), LZOO (large zooplankton), CLAD (cladocerans), and ZOO:CHLA (zooplankton:chlorophyll a ratio). Microcrustacean metrics such as DAPHN (Daphnia), COP (copepods), CYCLO (cyclopoids), and CALA (calanoids) were good at differentiating between high and low water quality in trophic status (oligotrophic-eutrophic) and ecological potential (good or superior-moderate). Thus, zooplankton can be used as a valuable tool to determine water quality; we believe that zooplankton should be considered a Biological Quality Element withinWater Framework Directive monitoring programs for inland waters
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