880 research outputs found
Produção comercial de achigãs - primeira experiência em Portugal
Produção comercial de achigãs - primeira experiência em Portugal
Growth evaluation of largemouth bass raised in aquaculture - first results
Largemouth bass (Micropterus salmoides) (LB) is a freshwater fish introduced in Portugal (Azores) in the end of XIX Century. It is a very important fish in regional cuisine especially in Ribatejo, Beira Baixa and Alentejo regions. The Sociedade AgrÃcola Vale de Inguinhos S.A. (SAVI) is the first LB aquaculture industry with permission for production 61.5 tones LB/year. Because in Portugal there are no specific LB comercial feed compound SAVI is now evaluate the growth capacity of wild LB using a commercial feed formulated for seabream and European seabass (protein 47.7%, fat 17.3%). On September 2014 358 juvenile LB (0+ years) were caught from 5 small dams belonging to SAVI. Juvenile were stocked in a circular tank used for compound feed training and evaluate fish growth. On the day zero 57 fish were sampled. The average values were: weight 19.49g (±1.882); length 11.85cm (±0.275); K condition factor 1.170 (±0.081). During the compound feed training period (35 days) the survival rate was 90.2%. A sample of >60 LB was collected every ~30 days. Thirty-five days (n=67) and 67 days (n=80) after the end feed training period, a LB sample were controlled with the following results: weight, 35 days 15.31g (±2.681) and 67 days 20.46g (±5.363) (P0.05). Water temperature ranged 24.6ºC and 10.0ºC. The first results indicate there was a decrease in weight and K condition factor during feed training period. However, the mortality rate was acceptable. Between 35 to 67 days, largemouth bass weight and length increased significantly. We conclude that commercial compound used at SAVI is appropriate to feed juveniles Micropterus salmoides
Nitric oxide synthesis and biological functions of nitric oxide released from ruthenium compounds
During three decades, an enormous number of studies have demonstrated the critical role of nitric oxide (NO) as a second messenger engaged in the activation of many systems including vascular smooth muscle relaxation. The underlying cellular mechanisms involved in vasodilatation are essentially due to soluble guanylyl-cyclase (sGC) modulation in the cytoplasm of vascular smooth cells. sGC activation culminates in cyclic GMP (cGMP) production, which in turn leads to protein kinase G (PKG) activation. NO binds to the sGC heme moiety, thereby activating this enzyme. Activation of the NO-sGC-cGMP-PKG pathway entails Ca2+ signaling reduction and vasodilatation. Endothelium dysfunction leads to decreased production or bioavailability of endogenous NO that could contribute to vascular diseases. Nitrosyl ruthenium complexes have been studied as a new class of NO donors with potential therapeutic use in order to supply the NO deficiency. In this context, this article shall provide a brief review of the effects exerted by the NO that is enzymatically produced via endothelial NO-synthase (eNOS) activation and by the NO released from NO donor compounds in the vascular smooth muscle cells on both conduit and resistance arteries, as well as veins. In addition, the involvement of the nitrite molecule as an endogenous NO reservoir engaged in vasodilatation will be described
Effects of culture media and suspension expansion technologies in mesenchymal stem cell manufacturing - A computational bioprocess and bioeconomics study
Mesenchymal stem cell (MSC) based therapies are promising for a large spectrum of unmet medical needs. Despite this promise, the scaling-up of production of clinical grade MSCs is hindered by the use of planar technologies that require intensive labor and are not enough to meet market demands, as well as due to high product and process variability introduced by the use of xenogeneic materials. This work presents a new bioprocess and bioeconomics model of stem cell expansion to support informed decisions for stem cells process scaling up at reduced annual costs. The intrinsic equations and parameters that capture the cell biological features, according with their source and media used, are embedded in the model. A target number of cells per dose of 140 million and a GMP facility of 400 sq mt with 4 BSCs and 8 incubators will be used as the baseline for expansion of both bone marrow MSCs (BM-MSCs) and adipose stem cells (ASCs) using planar expansion technologies. The current standard medium for MSC culture containing fetal bovine serum (FBS) will be compared with the xeno-free alternative of human platelet lysate (hPL). The use of hPL for both cell sources results in an increase of the number of doses produced and a decrease of the cost of goods (CoG) per dose (Table 1). In order to improve the production capacity, 8 bioreactors with capacity up to 50L were input in the model, using xeno-free plastic microcarriers for cell adhesion and hPL as the culture medium. The model results indicate that the investment in the use of suspension cultures is valuable due to a considerable increase in the production and a decrease of CoG/dose. As the number of doses produced per year increases, the reagent costs dominate relatively to the facility costs (Fig. 1). Sensitivity analysis was performed by varying 11 model variables by +/- 33%. The main factors that influence annual capacity and CoGs are related to harvesting density and yield, growth rates and microcarrier area and concentration (Table 2). These findings may be used to improve the design of expansion methods with fully xeno-free materials and highlight the relevance of the optimization of harvesting and downstream processing protocols.
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Dried brewers grains in growing rabbits: nutritional value and effects on performance
[EN] Two assays were carried out to determine i) the nutritional value of dried brewers’ grains and ii) the effects of inclusion of this ingredient in growing rabbit diets on animal performance and economic performance of the breeding unit. In the digestibility assay, a total of 28 male rabbits were distributed in 2 groups differing in the diet offered to animals: a reference diet (35.51% neutral detergent fibre and 16.50% crude protein [CP]) and a test diet (60% of reference diet and 40% of dried brewers grains). The dried brewers’ grain contained 37.9% of CP and 3371 kcal digestible energy/kg dry matter. In the performance study, 80 weaned rabbits (40 males and 40 females) were allotted at 40 d of age to 5 groups differing in the inclusion levels of dried brewers’ grains (0, 7, 14, 21 and 28%) from 40 d to 90 d of age. Inclusion of dried brewers’ grains did not affect the live weight at 90 d, the feed intake between 40 d and 90 d or the dressing percentage of rabbits (on average 223 g, 96 g/d and 51.3%, respectively). There was no effect of diet on the meat quality parameters (69.5% water holding capacity, 25.6% cooking loss, 3.4 kg/cm2 Warner-Bratzler shear force and pH 5.70) and inclusion levels above 14% reduced the feed cost (–18%; P<0.001), while inclusion above 21% improved net income (+32%; P<0.001). In conclusion, these results suggest that the use of dried brewers’ grains in diets for growing rabbits could improve the economic performance of the production system without impairing the animals’ performance.Lima, P.; Watanabe, P.; Cândido, R.; Ferreira, A.; Vieira, A.; Rodrigues, B.; Nascimento, G.... (2017). Dried brewers grains in growing rabbits: nutritional value and effects on performance. World Rabbit Science. 25(3):251-260. doi:10.4995/wrs.2017.6813.SWORD251260253Albuquerque, D. M. N., Lopes, J. B., Klein Junior, M. H., Merval, R. R., Silva, F. E. S., & Teixeira, M. P. F. (2011). ResÃduo desidratado de cervejaria para suÃnos em terminação. Arquivo Brasileiro de Medicina Veterinária e Zootecnia, 63(2), 465-472. doi:10.1590/s0102-09352011000200026AOAC International. 2005. Official methods of analysis of Association Official Analytical Chemists International. AOAC, Arlington VA. USA.Briganó, M. V., Pacheco, G. D., Bridi, A. M., Oba, A., Fonseca, N. A. N., & Silva, C. A. da. (2008). Desempenho e caracterÃsticas de carcaça de suÃnos submetidos a diferentes programas de restrição alimentar na fase dos 30 aos 118 kg. Revista Brasileira de Zootecnia, 37(8), 1398-1404. doi:10.1590/s1516-35982008000800009De Blas, J. C., Rodriguez, C. A., Bacha, F., Fernandez, R., & Abad-Guamán, R. (2015). Nutritive value of co-products derived from olivecake in rabbit feeding. World Rabbit Science, 23(4), 255. doi:10.4995/wrs.2015.4036Etchu K.A., Humbu M.E., Ndamukong K.J.N., Agbor E.B. 2012. Effect of varying levels of brewers' dried grain on the growth performance of weaner rabbits (Oryctolagus Cuniculus). Greener J. Agric. Sci., 2: 237-245.Fazano A.R.T., Zinsly C.F., Mattos W.R.S., Packer I.H. 1986. Digestibilidade e valor biológico da proteÃna da levedura seca (Saccharomyces spp.) e do farelo de soja para coelhos. Boletim de Indústria Animal, 46: 185-191.Lounaouci-Ouyaed G., Lakabi-ioualitene D., Berchiche M., Lebas F. 2008. Field beans and brewers grain as protein source for growing rabbits in Algeria: first results on growth and carcass quality. Nutrition and Digestive Physiology. In: 9th World Rabbit Congress, June 10-13, Verona, Italy. 723-728.Matterson L.D., Potter L.M., Stutz M.W., Singsen E.P. 1965. The metabolizable energy of feed ingredients for chickens. Storrs: University of Connecticut; Agricultural Experiment Station Research Report, 11: 11.National Research Council. 2007. Nutrient requirements of small ruminants: sheep, goats, cervids, and New World camelids. Washington, D.C.: National Academic Press, 292.Partridge G., Wyatt C. 1995. More flexibility with new generation of enzymes. World Poultry,11: 17-21.SAS 2000. SAS/STAT User's Guide (Release 6.12). SAS Inst. Inc., Cary NC, EUA.Villamide, M. J. (1996). Methods of energy evaluation of feed ingredients for rabbits and their accuracy. Animal Feed Science and Technology, 57(3), 211-223. doi:10.1016/0377-8401(95)00855-
Scalable generation of cerebellar neurons from pluripotent stem cells
Human induced pluripotent stem cells (iPSCs) have great potential for disease modeling and provide a valuable source for regenerative approaches. However, generating iPSC-derived models to study brain diseases remains a challenge. In particular, our ability to differentiate cerebellar neurons from pluripotent stem cells is still limited. Recently, we described the long-term culture of cerebellar neuroepithelium formed from human iPSCs, recapitulating the early developmental events of the cerebellum. Additionally, an efficient maturation of replated cerebellar progenitors into distinct types of functional cerebellar neurons was also achieved under defined and feeder-free conditions. However, developing a scalable protocol that allows to produce large numbers of organoids and high yields of mature neurons in a 3D bioreactor culture systems is still a difficult challenge. In this work, we present a new approach for the reproducible and scalable generation of mid-hindbrain organoids under chemically defined conditions by using the novel PBS 0.1 (100 mL) Vertical-Wheel single-use bioreactor. In this system, an efficient cell aggregation with shape and size-controlled aggregates can be obtained, which is important for homogeneous and efficient differentiation. Moreover, a larger amount of iPSC-derived aggregates can be generated without being excessively labour-intensive, achieving 431 ± 53.6 aggregates/mL at 24 hours after seeding. After differentiation, distinct types of cerebellar neurons were generated, including Purkinje cells (Calbindin+), Granule cells (BARHL1+ and Pax6+), Golgi cells (Neurogranin+ and GAD65+), Deep cerebellar nuclei projection neurons (TBR1+) and Non-Golgi-type interneurons (Parvalbumin+ and Calbindin-). These cells show signs of efficient maturation, staining positive for MAP2, and are able to change intracellular Ca2+ concentration following KCl stimulation. In this system, human iPSC-derived organoids are able to mature into different mature cerebellar neurons and to survive for up to 3 months, without replating and co-culture with feeder layers
Phosphorus removal by a fixed-bed hybrid polymer nanocomposite biofilm reactor
Eutrophication is one of the main challenges regarding the ecological quality of surface waters, phosphorus bioavailability being its main driver. In this context, a novel hybrid polymer nanocomposite (HPN-Pr) biofilm reactor aimed at integrated chemical phosphorus adsorption and biological removal was conceived. The assays pointed to removal of 1.2 mg P/g of reactive phosphorus and 1.01 mg P/g of total phosphorus under steady-state conditions. A mathematical adsorption–biological model was applied to predict reactor performance, which indicated that biological activity has a positive effect on reactor performance, increasing the amount of reactive phosphorus removed.The authors acknowledge the Portuguese Foundation for Science and Technology for the financial support under Project SFRH/BD/39085/2007
Development of a scale-down approach to the scalable culture of induced Pluripotent Stem Cells on microcarriers using single-use Vertical-Wheelâ„¢ bioreactors under xeno-free conditions
Induced Pluripotent Stem Cells (iPSC) are capable of extensive self-renewal while retaining the ability to differentiate into virtually all cell types of the body. These cells are the subject of much research and development activity aimed at the development of cell-based tools, which may speed drug discovery, and cell-based medical therapies that are being developed to address unmet medical needs. However, development of these therapies is hampered by manufacturing bottlenecks including production scale up to meet the anticipated demand. PBS Biotech, Inc. has developed a single use bioreactor with an innovative Vertical-Wheelâ„¢ design that promotes more homogenous and gentle particle suspension, under lower hydrodynamic shear environment than traditional bioreactor vessel design. Vertical-Wheel bioreactors are available from lab-scale vessels (PBS MINI) to larger production units (up to 500L). This study describes the culture of human iPSCs on microcarriers under xeno-free conditions using Vertical-Wheel bioreactors. Human iPSCs were cultured on microcarriers to provide surface for cell attachment using the chemically defined Essential 8 culture medium, a xeno-free, feeder-free culture medium. The culture conditions were optimized in terms of 1) initial cell/microcarrier ratio, 2) inoculation method and 3) agitation rate, in the PBS-0.1 vessel using 80 mL working volume. The cells were successfully expanded, up to a 7-fold increase in cell number, after 6 days in the bioreactor. Glucose consumption and lactate production were analyzed to prevent glucose starvation or excessive lactate accumulation. These optimized culture conditions were successfully repeated in a larger vessel, the PBS-0.5 using 300 mL working volume, demonstrating the scalability of the Vertical-Wheel system. With this PBS-0.5 bioreactor, 3 x 108 cells were produced after 6 days of operation, and the specific growth rate (0.72 day-1) was similar to the one observed with the PBS-0.1 (0.68 day-1). The applications of iPSC cells and their progeny, especially in clinical settings, will require a guarantee of cell quality. After PBS-MINI bioreactor culture, the expression of pluripotency markers, such as Oct4, Nanog, and SSEA4 was assessed by immunocytochemistry and flow cytometry. The directed differentiation into the neural lineage of the expanded cells was performed and the pluripotency of the cells was further tested after embryoid body formation. The robustness of this process method was evaluated by cultivating another iPSC cell line under the same process conditions, resulting in identical growth kinetics in the PBS MINI-0.1. The methodology developed herein, which grows human iPSC on microcarriers in single-use bioreactors using chemically defined xeno-free cultivation reagents provides a foundation upon which further refinement and scale-up of processes can be built for large scale production of iPSCs
Automatic lane detection in chromatography images
This paper proposes a method for automating the detection of lanes in Thin-Layer Chromatography images. Our approach includes a preprocessing step to detect the image region of interest, followed by background estimation and removal. This image is then projected onto the horizontal direction to integrate the information into a one-dimensional profile. A smoothing filter is applied to this profile and the outcome is the input of the lane detection process, which is performed in three phases. The first one aims at obtaining an initial set of candidate lanes that are further validated or removed in the second phase. The last phase is a refinement step that allows the inclusion of lanes that are not clearly distinguishable in the profile and that were not included in the initial set. The method was evaluated in 66 chromatography images and achieved values of recall, precision and F ß -measure of 97.0%, 99.4% and 98.2%, respectively
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