152 research outputs found
Revaluation of underutilized lemon fruits of southeastern Spain as a potential source of bioactive compounds and to be used in creative cuisine
In the present research colour, weight, morphological parameters and total antioxidant activity (TAA) of the edible tissues of three underutilised cultivars of lemon fruits was quantified. In addition, other fruit quality properties, such as organics acids and sugars concentrations in the lemon juices were analysed. Also, the evaluation of organoleptic attributes, such as sweetness, aroma, firmness, lack of bitterness, overall impression and notable feature of fruits was performed by a sensory panel. Results show significant differences on the analysed parameters among lemon cultivars. The relative proportion of each fruit tissue was similar for the three cultivars. 'Fino' and 'Sanguino' lemons showed the highest TAA, while the most appreciated by consumers according to the sensory panel results was 'Sanguino' lemon which could be due to their original colour. These traditional cultivars of lemon fruits could be used as ingredients in creative cuisine due to their attractive properties providing also nutritional and antioxidant compounds
Concepciones sobre la germinación de semillas de los niños y niñas de grado cuarto de la Institución Carlota Sánchez
La presente investigación pretendió comprender las concepciones de germinación que los niños y niñas de grado cuarto de básica primaria, de la Institución Educativa Carlota Sánchez, tienen sobre el proceso de la germinación de semillas. Para lograr el propósito de ésta, se realizó una investigación cualitativa de corte compresivo, que tuvo tres momentos: uno de identificación, uno de categorización y por ultimo uno de explicación. Para esto se tuvo en cuenta dos categorías para guiar la investigación que fueron la estructura y el proceso. Para recoger la información se construyó el instrumento: Taller sobre concepciones, el cuál fue elaborado desde las categorías: estructura y proceso, en el que se analizaron cada una de las concepciones encontradas y se contrastaron con los aportes del referente teórico sobre el proceso de la germinación, para comprender, interpretar y darle sentido a cómo concebían los niños y niñas este proceso. La investigación encontró que los niños y niñas de la Institución Educativa Carlota Sánchez tenían tres concepciones acerca de la germinación: En términos generales los niños y niñas conciben la germinación de las semillas como un medio de reproducción o multiplicación de las plantas, las cuales dependen de algunos factores o cuidados; estas concepciones concuerdan con la investigación realizada por la universidad de Vigo en la cual los estudiantes consideran que la semilla proviene del fruto y que la función de esta es originar otra planta. En la segunda concepción algunos niños y niñas conciben la germinación como un proceso que hace parte del ciclo vital: nacer, crecer, reproducirse y morir. Finalmente en la tercera conciben la germinación como contaminación tal vez porque hay una confusión en la fonética del termino pues parece que por la terminación de ambas palabras la niña hace esta asociación y es de esta manera como ella concibe la germinación. Esta investigación se proyectó para demostrar que las concepciones tienen un papel esencial y fundamental en la adquisición y construcción del conocimiento, por tanto es de suma importancia, que los docentes conozcan y tengan en cuenta estas concepciones a la hora de trabajar los contenidos escolares, logrando de esta forma, que evolucionen y se transformen para así adquirir y
aproximarse al conocimiento científico
Concurrent panel session 1: Challenges of economic growth & diversification & labor preparation in Las Vegas
Moderator: Dr. Mel Jameson, UNLV College of Business Scribe: Angela Moor, UNLV Department of History Conference white paper & Full summary of panel session, 6 page
Elche dates (phoenix dactylifera l.) responses to different post-harvest exogenous treatment
[SPA] Los dátiles recolectados en el palmeral de Elche, el más grande de Europa, se
encarecen por 3 razones básicamente: 1-como la reproducción tradicionalmente ha sido por
semillas, existe una gran variabilidad y por tanto poca homogeneidad del producto. 2-Como la
maduración de los dátiles es muy heterogénea dentro de un racimo, son necesarias varias
recolecciones para obtener todos los dátiles de una palmera. 3- Como maduran en otoño, hay
riesgo de lluvias, lo que ocasiona grandes pérdidas de dátiles. Por estas razones, se han
estudiado dátiles que pertenecen a palmeras de 3 huertos denominados Caqui, Los Olmos y
Los Cherros. El objetivo de este trabajo ha sido estudiar la efectividad de los tratamientos con
ácido acético, congelación o vaporización de dátiles en estado khalal, para acelerar su
maduración artificialmente y poder recolectar los dátiles por racimos enteros y antes de las
lluvias, lo que aumentaría la producción de dátiles y a menor coste, a la vez que aumentaría la
época en la que podrían salir al mercado. Para ello se han estudiado en los dátiles antes y
después del tratamiento, el peso, para estudiar las posibles pérdidas debidas a los tratamientos,
la firmeza, los sólidos solubles totales, acidez, índice de madurez y el color externo, así como
un test organoléptico. Los resultados indican que los dátiles pertenecientes a los huertos Caqui
y Los Olmos han madurado con buena calidad organoléptica al ser tratados con ácido acético
y al congelamiento, pero no se ha conseguido dátiles de calidad por el método de
vaporización en ningún tipo de dátil. Sin embargo, los dátiles de Los Cherros no han
madurado con buen estado organoléptico con ningún tratamiento.
[ENG] Dates harvested from Elche grove, the biggest within Europe, became expensive due
to three reasons: 1- Plant reproduction has been traditionally through seeds, therefore products
present a high variability, 2- Date ripening within a cluster is heterogeneous, therefore several
harvests are needed to obtain all the fruits form a palm tree, 3- Ripening occurs during
autumn, when rain can cause lose of yield. Date fruits from different palm trees belonging to 3 orchards, Caqui, Los Olmos and Los Cherros have been studied. The aim off the present
work has been to study the effectiveness of three ripening treatments during khalal stage:
acetic acid, freezing and vaporization, to accelerate ripening artificially. This will allow us to
collect all dates from a cluster at the same time and before the rains, which would increase
date yield, at a lower cost, and also would increase the marketing period. Different parameters
have been measured in date fruits before and after the treatments, as: fresh weight, firmness,
total soluble solids, acidity, ripening index, external colour and also an organoleptic test was
carried out. Results indicated that dates from Caqui and Los Olmos orchards have ripen with a
good organoleptic quality when treated with acetic acid and freezing treatment, but not quality
dates were obtained with vaporization treatment. Dates fruits from Los Cherros orchard did
not present a good sensorial analysis under any of the ripening treatments.Agradecemos a la empresa Viveros Huerto del Cura S.A. la donación del material
vegetal, sin el cual no se hubiera podido realizar este trabajo
The calcilytic agent NPS 2143 rectifies hypocalcemia in a mouse model with an activating calcium-sensing-receptor (CaSR) mutation:relevance to autosomal dominant hypocalcemia type 1 (ADH1)
Autosomal dominant hypocalcemia type 1 (ADH1) is caused by germline gain-of-function mutations of the calcium-sensing receptor (CaSR) and may lead to symptomatic hypocalcemia, inappropriately low serum parathyroid hormone (PTH) concentrations and hypercalciuria. Negative allosteric CaSR modulators, known as calcilytics, have been shown to normalise the gain-of-function associated with ADH-causing CaSR mutations in vitro and represent a potential targeted therapy for ADH1. However, the effectiveness of calcilytic drugs for the treatment of ADH1-associated hypocalcemia remains to be established. We have investigated NPS 2143, a calcilytic compound, for the treatment of ADH1 by in vitro and in vivo studies involving a mouse model, known as Nuf, which harbors a gain-of-function CaSR mutation, Leu723Gln. Wild-type (Leu723) and Nuf mutant (Gln723) CaSRs were expressed in HEK293 cells and the effect of NPS 2143 on their intracellular calcium responses determined by flow cytometry. NPS 2143 was also administered as a single intraperitoneal bolus to wild-type and Nuf mice and plasma concentrations of calcium and PTH, and urinary calcium excretion measured. In vitro administration of NPS 2143 decreased the intracellular calcium responses of HEK293 cells expressing the mutant Gln723 CaSR in a dose-dependent manner, thereby rectifying the gain-of-function associated with the Nuf mouse CaSR mutation. Intraperitoneal injection of NPS 2143 in Nuf mice led to significant increases in plasma calcium and PTH without elevating urinary calcium excretion. These studies of a mouse model with an activating CaSR mutation demonstrate NPS 2143 to normalize the gain-of-function causing ADH1, and improve the hypocalcemia associated with this disorder
An Inhibitory Effect of Extracellular Ca2+ on Ca2+-Dependent Exocytosis
Aim: Neurotransmitter release is elicited by an elevation of intracellular Ca 2+ concentration ([Ca 2+] i). The action potential triggers Ca 2+ influx through Ca 2+ channels which causes local changes of [Ca 2+] i for vesicle release. However, any direct role of extracellular Ca 2+ (besides Ca 2+ influx) on Ca 2+-dependent exocytosis remains elusive. Here we set out to investigate this possibility on rat dorsal root ganglion (DRG) neurons and chromaffin cells, widely used models for studying vesicle exocytosis. Results: Using photolysis of caged Ca 2+ and caffeine-induced release of stored Ca 2+, we found that extracellular Ca 2+ inhibited exocytosis following moderate [Ca 2+]i rises (2–3 mM). The IC50 for extracellular Ca 2+ inhibition of exocytosis (ECIE) was 1.38 mM and a physiological reduction (,30%) of extracellular Ca 2+ concentration ([Ca 2+]o) significantly increased the evoked exocytosis. At the single vesicle level, quantal size and release frequency were also altered by physiological [Ca 2+] o. The calcimimetics Mg 2+,Cd 2+, G418, and neomycin all inhibited exocytosis. The extracellular Ca 2+-sensing receptor (CaSR) was not involved because specific drugs and knockdown of CaSR in DRG neurons did not affect ECIE. Conclusion/Significance: As an extension of the classic Ca 2+ hypothesis of synaptic release, physiological levels of extracellular Ca 2+ play dual roles in evoked exocytosis by providing a source of Ca 2+ influx, and by directly regulatin
Presynaptic External Calcium Signaling Involves the Calcium-Sensing Receptor in Neocortical Nerve Terminals
Nerve terminal invasion by an axonal spike activates voltage-gated channels, triggering calcium entry, vesicle fusion, and release of neurotransmitter. Ion channels activated at the terminal shape the presynaptic spike and so regulate the magnitude and duration of calcium entry. Consequently characterization of the functional properties of ion channels at nerve terminals is crucial to understand the regulation of transmitter release. Direct recordings from small neocortical nerve terminals have revealed that external [Ca(2+)] ([Ca(2+)](o)) indirectly regulates a non-selective cation channel (NSCC) in neocortical nerve terminals via an unknown [Ca(2+)](o) sensor. Here, we identify the first component in a presynaptic calcium signaling pathway.By combining genetic and pharmacological approaches with direct patch-clamp recordings from small acutely isolated neocortical nerve terminals we identify the extracellular calcium sensor. Our results show that the calcium-sensing receptor (CaSR), a previously identified G-protein coupled receptor that is the mainstay in serum calcium homeostasis, is the extracellular calcium sensor in these acutely dissociated nerve terminals. The NSCC currents from reduced function mutant CaSR mice were less sensitive to changes in [Ca(2+)](o) than wild-type. Calindol, an allosteric CaSR agonist, reduced NSCC currents in direct terminal recordings in a dose-dependent and reversible manner. In contrast, glutamate and GABA did not affect the NSCC currents.Our experiments identify CaSR as the first component in the [Ca(2+)](o) sensor-NSCC signaling pathway in neocortical terminals. Decreases in [Ca(2+)](o) will depress synaptic transmission because of the exquisite sensitivity of transmitter release to [Ca(2+)](o) following its entry via voltage-activated Ca(2+) channels. CaSR may detects such falls in [Ca(2+)](o) and increase action potential duration by increasing NSCC activity, thereby attenuating the impact of decreases in [Ca(2+)](o) on release probability. CaSR is positioned to detect the dynamic changes of [Ca(2+)](o) and provide presynaptic feedback that will alter brain excitability
Calcimimetic and calcilytic therapies for inherited disorders of the calcium-sensing receptor signalling pathway
The calcium-sensing receptor (CaS receptor) plays a pivotal role in extracellular calcium homeostasis, and germline loss-of-function and gain-of-function mutations cause familial hypocalciuric hypercalcaemia (FHH) and autosomal dominant hypocalcaemia (ADH), respectively. CaS receptor signal transduction in the parathyroid glands is probably regulated by G-protein subunit α11 (Gα11) and adaptor-related protein complex-2 σ-subunit (AP2σ), and recent studies have identified germline mutations of these proteins as a cause of FHH and/or ADH. Calcimimetics and calcilytics are positive and negative allosteric modulators of the CaS receptor that have potential efficacy for symptomatic forms of FHH and ADH. Cellular studies have demonstrated that these compounds correct signalling and/or trafficking defects caused by mutant CaS receptor, Gα11 or AP2σ proteins. Moreover, mouse model studies indicate that calcilytics can rectify the hypocalcaemia and hypercalciuria associated with ADH, and patient-based studies reveal calcimimetics to ameliorate symptomatic hypercalcaemia caused by FHH. Thus, calcimimetics and calcilytics represent targeted therapies for inherited disorders of the CaS receptor signalling pathway
Stability Characterization of a Polysorbate 80-Dimethyl Trisulfide Formulation, a Cyanide Antidote Candidate
ChemInform Abstract: Preparation and Diazodecomposition Reaction of an α- Diazocarbonyl-Tethered Tricarbonyl(η4-cyclohexadiene)iron Complex ( IV).
- …