Interactive effects of solar UV radiation and ammonium on the biomass andnutritional compound production in tank cultivated Hydropuntia corne (Rhodophyta)

Figueroa et al. (2016) Acta Aquaculture 16, 331-332Introduction Hydropuntia cornea is a red alga species cultivated in tanks under nitrogen enrichment with high biomass production and content of high value bioactive compounds (Figueroa et al., 2012; Robledo et al, 2014). In this study, the combined effects (2 × 2 factorial design) of solar radiation (in door (I), green house cutting off the UV radiation and out-door (O) with UV radiation) and nitrogen (ammonium) under high (HN) and low (LN) levels on biomass production (g DW m-2 d-1), biofiltration as Nitrogen uptake efficiency (NUE, %) and Nitrogen uptake rate (NUR, mmol N m-2 h-1), photosynthetic activity as maximal electron transport rate (ETRmax), starch content and antioxidant activity were analyzed in H.cornea grown in tanks for 35 days in the above mentioned conditions. Material and methods The red seaweed Hydropuntia cornea was cultivated in cylindrical tanks of 90 L (0.17 m2 superficial area) with open flow-through N and P-enrichment (5 NH4Cl: 1 KHPO4, in a concentration ranges between 50 - 250 µM). Seaweed density assayed in tanks was 9 g FW L-1. Turnover rates were 64 and 6.4 vol d-1 in high and low flow rate, respectively. Photosynthetic activity was measured by using in vivo chlorophyll a fluorescence associated to photosystem II i.e. Electron transport rate (ETR) expressed as μmol electrons m-2 s-1. Starch (%) was determined according to anthrone method (Brooks et al. 1986) and antioxidant activity was evaluated following ABTS method (Ree et al., 1999) and expressed as Trolox equivalent (μM TEAC g-1 DW). Results Maximal photosynthetic production (ETRmax) increased throughout the culture time. (Fig. 1.A). After 35 d culture, ETRmax was higher under HN than that under LN both under in door and out door conditions (Fig.1A). However, biomass production expressed as g DW m-2 d-1 decreased throughout the experimental time (Fig 1.B). After 35d culture the highest biomass production was reached under HN-O and the lowest under LN-O although the differences were not so high (Fig.1B). The maximal efficiency of N assimilation (NUE %) was greater under LN (98%) than that under HN treatment (72%). NUE decreased throughout the time although after 35 d a clear increase was observed (Table 1). In contrast, the maximal nitrogen uptake rate (NUR) was higher under HN (45.5 mmol N m-2 h-1) than that under LN (25.8 mmol N m-2 h-1). The highest values of both NUE and NUR were obtained under solar radiation (outdoor treatments). Starch ranged from 25.1% (LN-I, 21 d) to 49.6 % (LN-O, 28 d) whereas the highest antioxidant activity was reached under LN-O after 21 d culture (68.5 μM TEAC g-1 DW). After 35d the highest level was again under LN-O (65.2 μM TEAC g-1 DW) followed by HN-O treatment (57.3 μM TEAC g-1 DW).Discussion and conclusions Ammonium supply, simulating fishpond effluents, and full solar irradiation (presence of UV radiation) have a positive effect on photosynthetic rate as ETRmax. The decrease in biomass production in spite of the increase of photosynthetic activity and nitrogen uptake rate is explained because the algae through the time could inverse more energy for the accumulation of metabolites (starch and antioxidant compounds) that that for growth. In any case the highest accumulation of starch and antioxidant activity were observed in the treatments associated to the greatest stress conditions i.e LN and outdoor culture due to UVR can negatively affect biological processes related to growth. As expected, under HN supply NUE was lower than that under LN but NUR was the reverse. H. cornea grown in simulated fishpond effluents displays a high biofiltration rate of inorganic N and accumulates commercially N compounds, as the photoprotector-antioxidant substances, mycosporine-like aminoacids (Figueroa et al., 2012) and C-compounds for nutritional uses or bioethanol production. In this study, the antioxidant activity was much higher than that reported in other seaweeds (Matanjun et al., 2008). H. cornea can be cultured and used to remove nutrient-rich fishpond effluents from aquaculture industries and besides, this biomass provides compounds of high added value for the biotechnology industry. References Brooks, J.R., Griffin, V.K., Kattan, M.W. 1986.A modified method for total carbohydrate analysisof glucose syrups, maltodextrins and other starch hydrolysis products. Cereal Chem 63:465-466. Figueroa, F. L., Korbee, N., Abdala, R., Jerez, C. G., López-de la Torre, M., Güenaga, L., Gómez-Pinchetti, J. L. 2012. Biofiltration of fishpond effluents and accumulation of N-compounds (phycobiliproteins and mycosporine-like amino acids) versus C-compounds (polysaccharides) in Hydropuntia cornea (Rhodophyta). Marine Pollution Bulletin, 64(2), 310-318. Matanjun, P., Mohamed, S., Mustapha, N.M., Ming, C.H. 2008. Antioxidant activities and phenolics content of eight species of seaweeds from north Borneo. J Appl Phycol 20:367–373. Re, R., Pellegrini, N., Proteggente, A., Pannala, A.,Yang,M., Rice-Evans, C. 1999. Antioxidant activity applying an improved ABTS radical cation decolorization assay. Free Radic Biol Med 26:1231–1237. Robledo, D., Navarro‐Angulo, L., Valdes Lozano, D., Freile‐Pelegrín, Y. 2014. Nutrient removal efficiency of Hydropuntia cornea in an integrated closed recirculation system with pink shrimp Farfantepenaeus brasiliensis. Aquaculture Research, 45(10), 1648-1658Universidad de Málaga.Campus de Excelencia Internacional Andalucia Tech

It support for mass customization

Many authors have written about Mass Customization and its features and categories. Literature on the implementation of Mass Customization, and in particular the supporting information technology, is scant. This paper attempts to fill this gap by focusing on this subject. We determine the key functional requirements and identify possible implementations to show the existence of enabling information technologies for Mass Customization

What Is Driving The TFP Slowdown? Insights From a Schumpeterian DSGE Model

In this paper, I incorporate a Schumpeterian mechanism of creative destruction in a medium-scale DSGE framework. In the model, a sector of profit-maximizing innovators invests in R&D and endogenously gen- erates productivity gains, ultimately determining the economy's growth rate. I estimate the model using Bayesian methods on U.S. data of the last 25 years (1993q1-2018q4) in order to disentangle the key forces underlying the productivity slowdown experienced by the US economy since the early 2000s. In contrast with the previous literature, I exploit Fernald (2014) data on TFP, factor utilization and labour quality to discipline the production function, and find that the bulk of the TFP slowdown is due to a decrease in innovation's ability to generate TFP gains. These findings challenge the view of a large part of the literature, according to which the recent TFP dynamics in the US are mostly driven by demand slumps and/or liquidity crunches

What Is Driving The TFP Slowdown? Insights From a Schumpeterian DSGE Model

In this paper, I incorporate a Schumpeterian mechanism of creative destruction in a medium-scale DSGE framework. In the model, a sector of profit-maximizing innovators invests in R&D and endogenously gen- erates productivity gains, ultimately determining the economy's growth rate. I estimate the model using Bayesian methods on U.S. data of the last 25 years (1993q1-2018q4) in order to disentangle the key forces underlying the productivity slowdown experienced by the US economy since the early 2000s. In contrast with the previous literature, I exploit Fernald (2014) data on TFP, factor utilization and labour quality to discipline the production function, and find that the bulk of the TFP slowdown is due to a decrease in innovation's ability to generate TFP gains. These findings challenge the view of a large part of the literature, according to which the recent TFP dynamics in the US are mostly driven by demand slumps and/or liquidity crunches

High-efficiency all-solution-processed light-emitting diodes based on anisotropic colloidal heterostructures with polar polymer injecting layers

Colloidal quantum dots (QDs) are emerging as true candidates for light-emitting diodes with ultrasaturated colors. Here, we combine CdSe/CdS dot-in-rod hetero-structures and polar/polyelectrolytic conjugated polymers to demonstrate the first example of fully solution-based quantum dot light-emitting diodes (QD-LEDs) incorporating all-organic injection/transport layers with high brightness, very limited roll-off and external quantum efficiency as high as 6.1%, which is 20 times higher than the record QD-LEDs with all-solution processed organic interlayers and exceeds by over 200% QD-LEDs embedding vacuum-deposited organic molecules

Extracellular polymeric substances produced by the Thermophilic Cyanobacterium Gloeocapsa gelatinosa: characterization and assessment of their antioxidant and metal-chelating activities

Cyanobacteria, particularly thermophilic strains, represent an important potential source of EPSs, harboring structural complexity that predicts diverse and specific bioactive potential. The ther mophilic cyanobacteria Gloeocapsa gelatinosa, isolated from a natural hot source in Ain Echfa (Tunisia), was cultivated in a cylindrical reactor, and the production of biomass and EPSs was investigated. Results revealed that the strain is amongst the most efficient EPSs producers (0.89 g L−1 ) and that EPSs production was not correlated with the growth phase. EPSs were sulfated heteropolysaccharides containing carbohydrates (70%) based on nine different monosaccharides, mainly mannose (22%), and with the presence of two uronic acids. EPSs were formed by two polymers moieties with a molecular weight of 598.3 ± 7.2 and 67.2 ± 4.4 kDa. They are thermostable in temperatures exceeding 100 ◦C and have an anionic nature (zeta potential of −40 ± 2 mV). Atomic force microscopy showed that EPSs formed multimodal lumps with 88 nm maximum height. EPSs presented high water holding capacity (70.29 ± 2.36%) and solubility index (97.43 ± 1.24%), and a strong bivalent metal sorption capacity especially for Cu2+ (91.20 ± 1.25%) and Fe2+ (75.51 ± 0.71%). The antioxidant activity of G. gelatinosa EPSs was investigated using four methods: the β-carotene-bleaching activity, DPPH assays, iron-reducing activity, and metal-chelating activity. EPS has shown high potential as free radicals’ scavenger, with an IC50 on DPPH (0.2 g L−1 ) three-fold lower than ascorbic acid (0.6 g L −1 ) and as a metal chelating activity (IC50 = 0.4 g L−1 ) significantly lower than EDTA. The obtained results allow further exploration of the thermophilic G. gelatinosa for several biotechnological and industrial applications.info:eu-repo/semantics/publishedVersio

Production of exopolymer substances from the thermophilic chlorophyte Graesiella: industrial and ecological applications

Microalgal extracellular polymeric substances (EPSs) are heteropolysaccharides that have characteristics suitable for industrial and biotechnological applications. Notably, they have strong anionic nature and high hydrophobicity. Nevertheless, systematic studies to demonstrate the viability of the production of EPSs on an industrial scale are still crucial. In this research, the chlorophyte Graesiella was grown on a raceway pond to view its EPS valorization. The biomass production achieved a maximum of 1.98 g L−1 and an EPS production of 1.6 g L−1 after six production days. The Graesiella EPSs with a molecular weight above 100 kDa are sulfated exopolymers containing mainly polysaccharide (70%) and protein (16%). The EPSs produced more stable emulsions with hydrocarbons and oils than Tween-20. The emulsification indices with n-hexane (88%) and maize oil (28%) indicate the EPSs’ strong emulsion-stabilizing capacity. The EPSs showed a peak flocculating percentage of 95% to kaolin suspension, with better flocculation performance than Al2(SO4)3 and alginate. Moreover, Graesiella EPSs had a significant effect on antimicrobial activity, significantly inhibiting fungal growth (71% for Botytis cinerea and 87% for Fusarium oxysporum), spore germination (100% of inhibition at a concentration of 1.8 g L−1), and mycelium growth (68% of inhibition). Also, Graesiella EPSs acted as a bactericide against Vibrio anguilaruim and Listonella anguilaruim (100% inhibition). EPSs were also found to have potent antioxidant activity compared with L-ascorbic acid. The obtained results open new perspectives to the further exploration of Graesiella sp. as a potential EPS producer, making it a promising candidate for numerous industrial applications.info:eu-repo/semantics/publishedVersio

Functional, rheological, and antioxidant properties of extracellular polymeric substances produced by a thermophilic cyanobacterium Leptolyngbya sp

Extracellular polymeric substances (EPSs) produced by the flamentous cyanobacterium identifed as Leptolyngbya sp. IkmLPT16 were isolated and characterized chemically, and their antioxidant, functional, and rheological properties were studied. The strain produces a signifcant amount of EPSs (2.15 g L−1) conjointly with a biomass production achieved at a maximum of 1.35 g L−1 after nine production days. Chemical analysis of EPSs revealed the presence of mannose (35%), arabinose (24%), glucose (15%), rhamnose (2%), and one uronic acid (8%). Fourier transformed infrared spectrum of EPSs further revealed the presence of νC-N groups indicating the presence of peptide moieties. Elemental analysis of EPSs showed the presence of sulfate groups (S=0.59%) as inorganic substituents. Functional properties of Leptolyngbya EPSs were determined based on water holding capacity, oil holding capacity, foaming ability, and metal sorption ability. Experimental results showed high water holding capacity (119%), water solubility index (97.43%), and oil holding ability (87.52%), with a strong metal sorption ability and consequent foam stability (22%). The rheological properties of EPSs were comparable with commercial xanthan gum with higher resistance to Temperature. Leptolyngbya sp. EPSs displayed an efective antioxidant activity via directly scavenging free radicals particularly DDPH• (IC50=4 mg. mL−1 against 10 mg. mL−1 for l-ascorbic acid) and •OH (IC50=10 mg. mL−1 against 20 mg. mL−1 for l-ascorbic acid) and as an iron-chelating agent (IC50=40 mg. mL−1 against 60 mg.mL−1 for EDTA). The outcomes of this study demonstrate the potential use of Leptolyngbya sp. EPSs in several food and pharmaceutical applications.info:eu-repo/semantics/publishedVersio

Predictive Coding beyond Gaussian Distributions

A large amount of recent research has the far-reaching goal of finding training methods for deep neural networks that can serve as alternatives to backpropagation (BP). A prominent example is predictive coding (PC), which is a neuroscience-inspired method that performs inference on hierarchical Gaussian generative models. These methods, however, fail to keep up with modern neural networks, as they are unable to replicate the dynamics of complex layers and activation functions. In this work, we solve this problem by generalizing PC to arbitrary probability distributions, enabling the training of architectures, such as transformers, that are hard to approximate with only Gaussian assumptions. We perform three experimental analyses. First, we study the gap between our method and the standard formulation of PC on multiple toy examples. Second, we test the reconstruction quality on variational autoencoders, where our method reaches the same reconstruction quality as BP. Third, we show that our method allows us to train transformer networks and achieve a performance comparable with BP on conditional language models. More broadly, this method allows neuroscience-inspired learning to be applied to multiple domains, since the internal distributions can be flexibly adapted to the data, tasks, and architectures used