Premise
The role of pollinators in evolutionary floral divergence has spurred substantial effort into measuring pollinator‐mediated phenotypic selection and its variation in space and time. For such ...estimates, the fitness consequences of pollination processes must be separated from other factors affecting fitness.
Methods
We built a fitness function linking phenotypic traits of food‐deceptive orchids to female reproductive success by including pollinator visitation and pollen deposition as intermediate performance components and used the fitness function to estimate the strength of pollinator‐mediated selection through female reproductive success. We also quantified male performance as pollinarium removal and assessed similarity in trait effects on male and female performance.
Results
The proportion of plants visited at least once by an effective pollinator was moderate to high, ranging from 53.7% to 85.1%. Tall, many‐flowered plants were often more likely to be visited and pollinated. Given effective pollination, pollen deposition onto stigmas tended to be more likely for taller plants. Pollen deposition further depended on traits affecting the physical fit of pollinators to flowers (flower size, spur length), though the exact relationships varied in time and space. Using the fitness function to assess pollinator‐mediated selection through female reproductive success acting on multiple traits, we found that selection varied detectably among taxa after accounting for sampling uncertainty. Across taxa, selection on most traits was stronger on average and more variable when pollination was less reliable.
Conclusions
These results support pollination‐related trait–performance–fitness relationships and thus pollinator‐mediated selection on traits functionally involved in the pollination process.
En este artículo se revisa el concepto de «arte expandido», formulado por la teórica de arte Rosalind Krauss en la revista October a finales de los años setenta y empleado a día de hoy también en los ...estudios literarios. Dicho concepto se revela útil para trazar un panorama de las relaciones entre arte y literatura a comienzos del siglo veintiuno. En este contexto, la obra última de Enrique Vila-Matas emerge como una referencia indiscutible. El estudio de sus libros Kassel no invita a la lógica (2014), Marienbad eléctrico (2015) y Cabinet d’amateur, una novela oblicua (2019), publicados todos ellos en la última década, nos permitirá acercarnos a su «literatura expandida» así como evidenciar la vocación multidisciplinar de una parte relevante de la literatura actual escrita tanto dentro como fuera de nuestras fronteras.
The Agricultural Research Centre of Mabegondo (Xunta de Galicia, A Coruéa, Spain) conserves one of the most important collections of phytogenetic resources of ecotypes and natural populations of ...grassland species from northwestern Spain, among them populations of ryegrass (Lolium spp.), one of the most cultivated forage grasses in the world. The objective of the present study was to evaluate the diversity among commercial cultivars and natural ryegrass populations with phenotypic traits and molecular markers. Eleven polymorphic microsatellites loci were used to analyze 58 ecotypes and 10 cultivars (680 DNA samples in total) differentiating 673 genotypes. Two main groups were detected by the Structure analysis, one related to Lolium perenne and a second to Lolium multiflorum. The first group showed two subgroups and the second three. The cluster of L. multiflorum showed two subgroups not related with the third cluster including commercial varieties, one from the Canary Islands (with Lolium rigidum included) and a second one from northwestern Spain, which presented specific agromorphological characteristics, such as lower FES (number of days from 1 January, when three heads per plant were flowering per plot), CRE (growth in flowering, in g of dry matter), and AIN (number of inflorescences per plant). This is the first time that a large amount of data on ryegrass from the Iberian Peninsula has been analyzed, obtaining a clear genetic differentiation of the autochthonous varieties from the commercial varieties analyzed. In addition, the genetic structure found in the ecotypes was related to the phenotypic variation analyzed. Being of interest in the conservation of biodiversity and in obtaining better adapted varieties of ryegrasses, due to their specific phenotypic traits, such as a lower FES, CRE and AIN.
biomass is a sustainable source of bioactive products for the food, cosmetic, and medicine industries. As well as primary metabolites, different secondary metabolites can be obtained via distinct ...enzymatic degradation of biomass. In this work, different hydrophilic extracts were obtained after treating the biomass with: (i) a serine
-peptidase (Alcalase
), (ii) a mixture of amino-, dipeptidyl-, and
-peptidases (Flavourzyme
), (iii) a mixture of
-1,3(4)-β-glucanase and an
-1,4-xylanase, and β-glucanase (Ultraflo
), and (iv) an
-1,3-glucanase (Vinoflow
) (all the enzymes from Novozymes A/S (bagsvaerd, Denmark)); with subsequent extraction of the biocomponents with an isopropanol/hexane mixture. The composition of each aqueous phase extract (in terms of amino acids, peptides, oligo-elements, carbohydrates, and phenols) and their in vitro functional properties were compared. The conditions described in this work using the enzyme Alcalase
permits the extraction of eight distinctive peptides. This extract is 7.3 times more anti-hypertensive, 106 times more anti-hypertriglyceridemic, 26 times more hypocholesterolemic, has 4.4 times more antioxidant activities, and has 2.3 times more phenols, than the extract obtained without any prior enzyme biomass digestion. Alcalase
extract is an advantageous product with potential application in functional food, pharmaceutics, and cosmetics.
There is no available information about mechanisms linking glucosensing activation in fish and changes in the expression of brain neuropeptides controlling food intake. Therefore, we assessed in ...rainbow trout hypothalamus the effects of raised levels of glucose on the levels and phosphorylation status of two transcription factors, FoxO1 and CREB, possibly involved in linking these processes. We also aimed to assess the changes in the levels and phosphorylation status of two proteins possibly involved in the modulation of these transcription factors: Akt and AMPK. Therefore, in pooled preparations of hypothalamus incubated for 3 and 6 h in the presence of 2, 4 or 8 mmol l
d-glucose, we evaluated the response of parameters related to glucosensing mechanisms, neuropeptide expression and levels and phosphorylation status of the proteins of interest. The activation of hypothalamic glucosensing systems and the concomitant enhanced anorectic potential occurred in parallel with activation of Akt and inhibition of AMPK. The changes in these proteins relate to neuropeptide expression through changes in the level and phosphorylation status of transcription factors under their control, such as CREB and FoxO1, which displayed inhibitory (CREB) or activatory (FoxO1) responses to increased glucose.
•Advanced selective synthesis of CLA rich phosphatidylcholines.•Selective acydolysis of phospholipids with new immobilized Lecitase Ultra.•Rapid, selective and high yield production of structured ...phospholipids.•New immobilized phospholipase A1 speeds up phosphatidylcholine acidolysis with CLA.•Overcoming structured phospholipid synthesis drawbacks: hydrolysis/selectivity/speed.
Phospholipids (PL) rich in conjugated linolenic acid (CLA) have important health effects. Yields of phosphatidylcholine (PC) acidolysis with CLA use to be limited to <30%, due to competitive side-hydrolysis. Duolite A658–Lecitase is a very suitable biocatalyst for this reaction.
In this study, PC hydrolysis has been practically eliminated using extremely dried lyophilized PC (279 ± 4 mg water/Kg PC), obtaining close to 100% molar yield of modified PC (72.3% CLA) with Duolite-Lecitase in 24 h, the highest yield reported in the literature for this reaction. It has been better improved by changing the immobilization support, using three food grade hydrophobic supports (Styrene, and two Octadecyl methacrylates (OM and OMC)). In only 2 h, with a 1/12 PC/CLA molar ratio at 50 °C, similar almost quantitative yields of PC with 74.4% CLA content has been obtained using OM-Lecitase. The fatty acid composition of modified PCs is not affected by the enzyme immobilization protocol.
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•Novozym® 435 modification with 2,4,6-trinitrobenzensulfonic acid favors oil reaction.•Support swelling by solvent accelerates alcoholysis catalyzed by Novozym® 435 adducts.•TNBS ...derivative is also more stable than Novozym® 435 in methanolysis with solvent.•Breaking of support particles is reduced by the 7 different modifications studied.•Product deposits do not impose any significant mass transfer restrictions.
Alcoholysis of oils mediated by immobilized lipases are limited by mass transfer effects on substrates. In this work, Novozym® 435 lipase was subjected to seven different chemical derivatizations. The effects of changes in the enzyme surface and changes of the support particles size, on substrates mass transfer restrictions were studied on the alcoholysis of Camelina oil in the presence or not of t-butanol as co-solvent.
Significant changes of the support particle size were detected after their chemical modification. The particle size of Lewatit VP OC 1600 support of Novozym® 435 diminished in solvent-free systems. Alcoholysis rates in t-butanol media were enhanced caused by two favorable effects of this solvent: substrates dissolution and support swelling. This latter effect was not sufficient to promote protein desorption during processing. The hydrophobic environment created by 2,4,6-trinitrobenzensulfonic acid (TNBS) derivatization favoured the oil conversion. The TNBS derivative was also more stable than Novozym® 435 in methanolysis with solvent.
Scanning electron microscopy revealed that after 14 reaction cycles of 24h, a large proportion of biocatalyst particles were broken; however, matrix rupture did not cause biocatalysts inactivation. All modifications studied seemed to protect the support particles from breaking. Accumulated product particles on all biocatalysts surfaces did not impose significant mass transfer restrictions to substrates, but prevented protein desorption in urea solution.
There is no information available on fish as far as the possible effects of ghrelin on hypothalamic fatty acid metabolism and the response of fatty acid-sensing systems, which are involved in the ...control of food intake. Therefore, we assessed in rainbow trout the response of food intake, hypothalamic fatty acid-sensing mechanisms and expression of neuropeptides involved in the control of food intake to the central treatment of ghrelin in the presence or absence of a long-chain fatty acid such as oleate. We observed that the orexigenic actions of ghrelin in rainbow trout are associated with changes in fatty acid metabolism in the hypothalamus and an inhibition of fatty acid-sensing mechanisms, which ultimately lead to changes in the expression of anorexigenic and orexigenic peptides resulting in increased orexigenic potential and food intake. Moreover, the response to increased levels of oleate of hypothalamic fatty acid-sensing systems (activation), expression of neuropeptides (enhanced anorexigenic potential) and food intake (decrease) were counteracted by the simultaneous treatment with ghrelin. These changes provide evidence for the first time in fish of a possible modulatory role of ghrelin on the metabolic regulation by fatty acid of food intake occurring in the hypothalamus.
We hypothesize that glucosensor mechanisms other than that mediated by glucokinase (GK) operate in hypothalamus and hindbrain of the carnivorous fish species rainbow trout and stress affected them. ...Therefore, we evaluated in these areas changes in parameters which could be related to putative glucosensor mechanisms based on liver X receptor (LXR), mitochondrial activity, sweet taste receptor, and sodium/glucose co-transporter 1 (SGLT-1) 6 h after intraperitoneal injection of 5 mL x Kg(-1) of saline solution alone (normoglycaemic treatment) or containing insulin (hypoglycaemic treatment, 4 mg bovine insulin x Kg(-1) body mass), or D-glucose (hyperglycaemic treatment, 500 mg x Kg(-1) body mass). Half of tanks were kept at a 10 Kg fish mass x m(-3) and denoted as fish under normal stocking density (NSD) whereas the remaining tanks were kept at a stressful high stocking density (70 kg fish mass x m(-3)) denoted as HSD. The results obtained in non-stressed rainbow trout provide evidence, for the first time in fish, that manipulation of glucose levels induce changes in parameters which could be related to putative glucosensor systems based on LXR, mitochondrial activity and sweet taste receptor in hypothalamus, and a system based on SGLT-1 in hindbrain. Stress altered the response of parameters related to these systems to changes in glycaemia.
Vascular dysfunction is considered a hallmark of ageing that has been associated with altered vasomotor responses, in which nitric oxide (NO) and reactive oxygen species participate. The consumption ...of Spirulina extracts, with antioxidant properties, increased recently.
This study investigates the effect of Spirulina aqueous extract (SAE) on the vascular function of the aorta from aged rats.
Aortic segments from aged male Sprague-Dawley rats (20-22 months old) were exposed to SAE (0.1% w/v, for 3 h) to analyse: (i) the vasodilator response induced by acetylcholine (ACh), by the NO donor sodium nitroprusside (SNP), by the carbon monoxide releasing molecule (CORM) and by the K
ATP
channel opener, cromakalim (CK); (ii) the vasoconstrictor response induced by KCl and noradrenaline (NA); (iii) the production of NO and superoxide anion, and (iv) the expression of the p-eNOS and HO-1 proteins.
Incubation with SAE increased the expression of p-eNOS (1.6-fold) and HO-1 (2.0-fold), enhanced NO release (1.4-fold in basal and 1.9-fold in ACh-stimulated conditions) while decreased the production of superoxide (0.7-fold). SAE also increased the sensitivity (measured as pEC
50
) to ACh (control: −7.06 ± 0.11; SAE: −8.16 ± 0.21), SNP (control: −7.96 ± 0.16; SAE: −9.11 ± 0.14) and CK (control: −7.05 ± 0.39; SAE: −8.29 ± 0.53), and potentiated the response to KCl (1.3-fold) and to NA (1.7-fold).
The antioxidant properties of SAE improved the vasomotor responses of aorta from aged rats. These results may support the use of Spirulina as a protection against vascular dysfunction.
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