2,184 research outputs found
Bacterial coaggregation in aquatic systems
The establishment of a sessile community is believed to occur in a sequence of steps where genetically distinct bacteria can become attached to partner cells via specific molecules, in a process known as coaggregation. The presence of bacteria with the ability to autoaggregate and coaggregate has been described for diverse aquatic systems, particularly freshwater, drinking water, wastewater, and marine water. In these aquatic systems, coaggregation already demonstrated a role in the development of complex multispecies sessile communities, including biofilms. While specific molecular aspects on coaggregation in aquatic systems remain to be understood, clear evidence exist on the impact of this mechanism in multispecies biofilm resilience and homeostasis. The identification of bridging bacteria among coaggregating consortia has potential to improve the performance of wastewater treatment plants and/or to contribute for the development of strategies to control undesirable biofilms. This study provides a comprehensive analysis on the occurrence and role of bacterial coaggregation in diverse aquatic systems. The potential of this mechanism in water-related biotechnology is further described, with particular emphasis on the role of bridging bacteria.This work was financially supported by: Base Funding UIDB/00511/2020 of LEPABE and UIDB/00081/2020 of CIQUP funded by national funds through the FCT/MCTES (PIDDAC); Project Biocide_for_Biofilm-PTDC/BII-BTI/30219/2017-POCI-01-0145-FEDER 030219, ABFISH–PTDC/ASP-PES/28397/2017-POCI-01-0145-FEDER 028397 and ALGAVALOR-POCI-01-0247-FEDER-035234, funded by FEDER funds through COMPETE2020–Programa Operacional Com petitividade e Internacionalização (POCI) and by national funds
(PIDDAC) through FCT/MCTES. This study was further supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. The authors also thank to CITAB (Centre for the Research and Technology of Agro-Environmental and Biological Sciences) under the scope of
the FCT funds with reference UIDB/AGR/04033/2020. Ana Afonso acknowledges the FCT grant 2020.04773.BD.info:eu-repo/semantics/publishedVersio
Cutting Forces Assessment in CNC Machining Processes: A Critical Review
Machining processes remain an unavoidable technique in the production of high-precision parts. Tool behavior is of the utmost importance in machining productivity and costs. Tool performance can be assessed by the roughness left on the machined surfaces, as well as of the forces developed during the process. There are various techniques to determine these cutting forces, such as cutting force prediction or measurement, using dynamometers and other sensor systems. This technique has often been used by numerous researchers in this area. This paper aims to give a review of the different techniques and devices for measuring the forces developed for machining processes, allowing a quick perception of the advantages and limitations of each technique, through the literature research carried out, using recently published worksThe present work was done and funded under the scope of the project ON-SURF (ANI | P2020 | POCI-01-0247-FEDER-024521, co-funded by Portugal 2020 and FEDER, through COMPETE 2020-Operational Programme for Competitiveness and Internationalisation. F.J.G. Silva also thanks INEGI-Instituto de Ciência e Inovação em Engenharia Mecânica e Engenharia Industria, due to its support.info:eu-repo/semantics/publishedVersio
DT-TTF Salts with [Cu(dcdmp)2]−: The Richness of Different Stoichiometries
(DT-TTF)[Cu(dcdmp)(2)] (1), (DT-TTF)(2)[Cu(dcdmp)(2)] (2), and (DT-TTF)(3)[Cu(dcdmp)(2)](2) (3) are three new charge transfer salts obtained by electrocrystallization of the donor DT-TTF (dithiophene-tetrathiafulvalene) with the diamagnetic copper complex [Cu(dcdmp)(2)](-) (dcdmp = 2,3-dicyano-5,6-dimercaptopyrazine). Compounds 1 and 3 crystallize in the triclinic system and consist of out-of-registry layers of mixed stacks of donor and acceptor molecules. (DT-TTF)(2)[Cu(dcdmp)(2)] presents a structure similar to the parent spin-ladder systems with donor stacks arranged in pairs; however, a magnetic spin-ladder behavior is not observed probably due to strong interactions between pairs. Compound 3, despite the mixed nature of the stacks, displays relatively high conductivity (7 S/cm) due to a one-dimensional network of interactions between donors.This work was supported by FCT (Portugal) through contracts PTDC/QEQ-SUP/1413/2012 and
UID/Multi/04349/2013 and by DGI, Spain (CTQ2013-40480), the Generalitat de Catalunya
(2014SGR0017), the CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN),
promoted by ISCIII, Spain. R. A. L. S. is thankful to FCT for the PhD grant
SFRH/BD/86131/2012.Peer reviewe
Construction and use of a tubular picrate ion-selective electrode for reducing sugar determination in Port wine by flow-injection analysis
A picrate ion-selective electrode without inner reference solution and based on bis(triphenylphosphoranylidene)ammonium picrate dissolved in 2-nitrophenyloctyl ether was constructed and its characteristics assessed. With respect to reducing sugar determination in Port wine, a tubular electrode based on the same sensor system was developed and incorporated into a flow-injection manifold devised for this determination. The methodology involves a reaction between the reducing sugar and picric acid, the decrease in the picrate concentration being monitored with the tubular electrode. A linear dependence between peak width, at a fixed potential and the logarithm of sugar concentration in the range 25–200 g l−1 was obtained. The proposed system allows wine samples to be injected with no previous treatment and allows a sample throughput of 50 determinations per hour, a relative standard deviation less than 4%, and the results are comparable to the reference procedures
By-products of camu-camu [Myrciaria dubia (Kunth) McVaugh] as promising sources of bioactive high added-value food ingredients: functionalization of yogurts
Camu-camu (Myrciaria dubia (Kunth) McVaugh) is a fruit economically relevant to the
Amazon region, mostly consumed in the form of processed pulp. Our aim was to perform an
unprecedented comparative study on the chemical composition and bioactivities of the camu-camu
pulp and industrial bio-residues (peel and seed), and then the most promising fruit part was further
explored as a functionalized ingredient in yogurt. A total of twenty-three phenolic compounds were
identified, with myricetin-O-pentoside and cyanindin-3-O-glucoside being the main compounds
in peels, followed by p-coumaroyl hexoside in the pulp, and ellagic acid in the seeds. The peel
displayed the richest phenolic profile among samples, as well as the most significant antibacterial
(MICs = 0.625–10 mg/mL) and anti-proliferative (GI50 = 180 g/mL against HeLa cells) activities.
For this reason, it was selected to be introduced in a food system (yogurt). Taken together, our results
suggest the possibility of using the camu-camu peel as a source of food additives.Part of this work was supported by the Instituto Federal do Rondônia (IFRO) (Grant
nº 81/PROPESP/IFRO). The authors are grateful to FCT—Portugal and FEDER, under Programme PT2020, for financial support to CIMO (UID/AGR/00690/2019) and B. Albuquerque research grant (SFRH/BD/136370/2018); national funding by FCT, P.I., through the institutional scientific employment program-contract for L. Barros and R.C. Calhelha contracts; C. Pereira contract though the celebration of program-contract foreseen in No. 4, 5, and 6 of
article 23º of Decree-Law No. 57/2016, of 29 August, amended by Law No. 57/2017, of 19 July; to FEDER-Interreg España-Portugal for financial support through the projects 0377_Iberphenol_6_E and 0612_TRANS_CO_LAB_2_P; FEDER through the Regional Operational Program North 2020: project Mobilizador Norte-01-0247-FEDER-024479
(ValorNatural®).info:eu-repo/semantics/publishedVersio
Continuous production of melamine-formaldehyde microcapsules using a mesostructured reactor
A mesostructured NETmix reactor was adapted to develop a continuous process to produce microcapsules, focusing on the steps commonly used in batch formulation: the emulsion and cure. Microcapsules were formed through a polycondensation process by coating Miglyol, a skin-hydrating emollient, with melamine-formaldehyde, which is a resistant shell material with surface smoothness. Different recirculation times were tested for the cure step. Microcapsules show a spherical shape and smooth membrane. Efficiencies of encapsulation of 75%, core contents of 70%, and diameters around 20 μm, ideal range for textile impregnation, were obtained. Scanning electron microscopy shows the integrity of microcapsules on textiles after impregnation and their flexible behavior. The thermogravimetric analysis confirmed the thermal stability of microcapsules up to 210 °C. With the NETmix reactor, it is possible to reduce the cure time of traditional batch formulation in 80%, producing microcapsules with similar characteristics in a continuous process.This work was supported by Associate Laboratory LSRE-LCM
UID/EQU/50020/2019 funded by national funds through
FCT/MCTES (PIDDAC) and Project TexBioPro, POCI-01-
0247-FEDER-003472, funded by FEDER, through COMPETE
2020, under PT2020.info:eu-repo/semantics/publishedVersio
Adenosine A(2A) receptor blockade reverts hippocampal stress-induced deficits and restores corticosterone circadian oscillation
Maternal separation (MS) is an early life stress model that induces permanent changes in the central nervous system, impairing hippocampal long-term potentiation (LTP) and spatial working memory. There are compelling evidences for a role of hippocampal adenosine A(2A) receptors in stress-induced modifications related to cognition, thus opening a potential window for therapeutic intervention. Here, we submitted rats to MS and evaluated the long-lasting molecular, electrophysiological and behavioral impairments in adulthood. We then assessed the therapeutic potential of KW6002, a blocker of A(2A) receptors, in stress-impaired animals. We report that the blockade of A(2A) receptors was efficient in reverting the behavior, electrophysiological and morphological impairments induced by MS. In addition, this effect is associated with restoration of the hypothalamic-pituitary-adrenal axis (HPA-axis) activity, as both the plasma corticosterone levels and hippocampal glucocorticoid receptor expression pattern returned to physiological-like status after the treatment. These results reveal the involvement of A(2A) receptors in the stress-associated impairments and directly in the stress response system by showing that the dysfunction of the HPA-axis as well as the long-lasting synaptic and behavioral effects of MS can be reverted by targeting adenosine A(2A) receptors. These findings provide a novel evidence for the use of adenosine A(2A) receptor antagonists as potential therapy against psychopathologiesWe acknowledge Alexandre de Mendonca, David Blum and Rodrigo Cunha for helpful discussions. VLB is thankful to Joao Baiao and Carla Batalha for technical assistance. VLB has been awarded a PhD fellowship from Fundacao para a Ciencia e Tecnologia (BD/63041/2009). LVL is funded by Fundacao para a Ciencia e Tecnologia (PTDC/SAU-NEU/099853/2008) and by EU programme Egide-Pessoa. YB and CEM were funded by the Ministry for Education and Research (BMBF, Grant number 01EW0911) in the frame of ERA-NET NEURON
Coeval perpendicular shortenings in the Brasilia belt : collision of irregular plate margins leading to oroclinal bending in the Neoproterozoic of central Brazil
The three belts which form the Tocantins province (central Brazil) records
Neoproterozoic-EoPaleozoic collisions involving the Amazon and São Francisco
paleocontinents and the Paraná continental block. The Brasília belt is a typical
orocline bended around the WNW—ESE striking Pirineus Zone of High Strain
(PZHS) and is comprised of the NE-trending (northern) and SE-trending
(southern) segments. The Brasília dome is an N—S elliptical structural window
situated in the center of the belt, at the eastern end of the PZHS. It evidences
Di— D₂ and D₃ɴ shortenings (~ 750—590 Ma) due to ocean closure and
Amazon- São Francisco collision following a WNW—ESE path, and
demonstrates similar evolution for both segments of the belt. However, in the
southern segment, D₁—D₂ structures are deformed by shortening in the SW-NE
direction (D₃S). New data demonstrating D₁—D₂ and D₃ɴ tectonites deformed
by D₃S struc- tures in the area close to the dome's SW margin and SE of the
PZHS support understanding the Brasília belt and oroclinal bending as a
consequence of the collision of two (Amazon and São Francisco) irregular
continental margins leading to separation-rotation of the Paraná block from the
Amazon paleocontinent and the Paraná-São Francisco collision
Release of a New Forage Bermudagrass Cultivar from the USDA-NPGS Cynodon Collection
Warm-season perennial grasses are the backbone of the pasture-based livestock industry in the southeastern USA. In Florida specifically, bahiagrass (Paspalum notatum Flugge) and bermudagrass (Cynodon spp.) support 1 million head of cattle and 15,000 beef cattle operations. Bermudagrass is the most widely planted forage species in the southeastern USA, planted in approximately 15 million ha and used for grazing, hay and silage. The genus Cynodon is native to southern Africa and germplasm collections have revealed a high degree of genetic variability within the genus. The United States Department of Agriculture National Plant Germplasm System (USDA-NPGS) maintains a collection of bermudagrass plant introduction (PIs) in Griffin, GA, USA and the USDA Georgia Coastal Plains Experiment Station, Tifton, GA, maintains additional forage germplasm. Multi-location trials were established in 2014 in four states (FL, GA, NC and OK) to screen the collection for herbage accumulation (HA) and nutritive value (NV). Due to the large genotype by environment interaction for HA across states, we focused on selecting accessions adapted to South Georgia and Florida. Several PIs showed improved HA and NV compared to ‘Tifton 85’ across several trials and years. Particularly, PI 316510 produced high HA in Citra, FL and Tifton, GA, had improved NV traits, and faster establishment compared to Tifton 85. We confirmed that PI 316510 is tetraploid by chromosome counts and flow cytometry. The PI 316510 has been released by the University of Florida under the name “Newell”
Assembléias de Formicidae epigéas no entorno do Parque Nacional da Chapada Diamantina, Bahia, Brasil
Ants at four localities were studied in the surroundins of the National Park of Chapada Diamantina, central region of the State of Bahia, Brazil. Vegetation belongs to the Atlantic forest biome (Sazonal Semideciduous Forest), but it is regionally surrounded by other vegetation formations, mainly of the caatinga and altitude field biomes. In each one of the four areas, 50 samples of ants were collected with a Winkler extractor and anoother 50 with pitfall traps. A total of 191 species distributed in 47 genera was found. The Winkler trap was most efficient in species capture. The communities of the two areas closer to the National Park, at Lençois presented greater similarity between themselves and larger species number, perhaps because they had been less used by humans in the last 40 years, than the two other areas studied, situated in farms and more distant to the Park. The comparative analysis of the similarity indices, calculated from the capture results obtained with the pit-fall traps and Winkler extractor, indicates that the two trees made from the results of all four areas are identical. Although this result was unexpected, it shows that whatever the collection method and the fauna segment studied, the relative similarity between series is respected. If this observation is verified under additional experimental conditions and biomes, it indicates that if the purpose is to use ants as bioindicators, several sampling techniques can be indiscriminately used for the comparative evaluation of ant assemblages, even if different strata are sampled for their fauna, with no impact on the conclusions that can be drawn about their characteristics of degradation or conservation.Foram realizadas coletas de Formicidae em quatro localidades situadas no entorno do Parque Nacional da Chapada Diamantina, região central do Estado da Bahia. A vegetação pertence ao bioma Mata Atlântica (Floresta Estacional Semidecidual), mas é regionalmente circundada por outras formações vegetais, sobretudo dos biomas caatinga e campo rupestre. Em cada uma das quatro áreas, foram coletadas 50 amostras de formigas da serapilheira com o extrator de Winkler e outros 50, com armadilhas de tipo pitfall. Foi encontrado um total de 191 espécies, distribuídas em 47 gêneros. A armadilha de Winkler foi a mais eficiente na captura de espécies. As comunidades das duas áreas situadas mais próximas ao Parque Nacional, em Lençóis, foram as que apresentaram maior similaridade entre si e maior número de espécies, talvez porque foram menos utilizadas pelo homem nos últimos 40 anos do que as duas outras áreas estudadas, situadas em fazendas mais distantes do Parque. A análise comparativa dos índices de similaridade, calculados a partir dos resultados das capturas realizadas com as armadilhas pit-fall e extrator de Winkler, indica que os dois agrupamentos relativos às quatro áreas estudadas são estritamente iguais. Apesar de esse resultado ser surpreendente, ele mostra que, qualquer que seja o método de coleta, isto é, o segmento de fauna amostrada, a similitude relativa entre series amostrais é respeitada. Se essa colocação se verificar em outras condições experimentais e outros biomas, ela indica que, em caso de uso das formigas como indicadores biológicos, diversas metodologias de amostragens poderiam ser indiscriminadamente utilizadas na avaliação comparativa de assembléias de Formicidae, mesmo se forem estudados estratos da fauna diferentes, sem prejuízo das conclusões que podem ser retiradas sobre as características de degradação ou de conservação de cada uma
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