Shelf-Ocean material exchange influencing the Atlantic chemical composition off NW Iberian margin since the last glaciation

Rivers are the main conduit of sediment to the shelf. The basin geology, the drainage area and the discharge rate are the major factors that determine their sediment load (Milliman and Syvistski, 1992). Besides suspended particles, dissolved components may also give some information on the eroded crust. Sr isotopes in carbonate shells of biological organisms have been used to study, in the geological record, the influence exerted by the chemical weathering of the continental crust on the seawater composition (Macdougall, 1991). In this work, Sr isotope ratios obtained in tests of foraminifera representing the last 40 ka are presented and discussed in the scope of the palaeogeographical evolution of NW Iberia. This work aims to present and discuss the results of Sr isotope analyses (performed, by TIMS, in the Isotope Geology Laboratory of the University of Aveiro) of tests of two species of foraminifera, from nine samples taken along the OMEX core KC 024-19 (181 cm; 42°08’98’’N, 10°29´96’’W, and 2765m), collected in the Galicia Bank area, off Galicia. Taking into account that Sr contained in the carbonate tests is usually considered as preserving the signature of the contemporaneous seawater, one planktonic species (Globigerina bulloides) and one benthic species (Cibicides wuellerstorfi) were selected in order to try to detect Sr isotope variations both through time and between two different levels of the water column. The core age model, which records the last 40 ka, is based on a combination of oxygen isotope stratigraphy, eight AMS 14C datings and the synchronisation of the last four Heinrich Events in the Iberian Margin sedimentary records. As a whole, the obtained 87Sr/86Sr ratios vary between 0.709209 and 0.709108, with a mean 2σ error of 0.000025. These values lie within the range of modern marine Sr isotope ratios (0.70910-0.70922), as previously defined using analyses of both seawater and marine carbonates (see compilation by Faure and Mensing, 2005). Despite their small variation, the 87Sr/86Sr ratios obtained in G. bulloides seem to indicate that Sr dissolved in seawater at the KC 024-19 core site became slightly less radiogenic after the Last Glacial Maximum (LGM). This decrease is concomitant with diminishing amounts of the detrital components in the sediments (Fig. 1). Therefore, both the composition of dissolved Sr, as revealed by results on tests of planktonic foraminifera, and the proportions of suspended terrigenous particulate material arriving at the KC 024-19 site point to a decreasing importance of the contribution of the erosion of the Iberian Variscan crust since the Last Glacial Maximum and in the Holocene. The 87Sr/86Sr ratios measured in tests of benthic foraminifera (C. wuellerstorfi) are more erratic and no correlation can be established with palaeogeographical/palaeoclimatic constraints. The difference between the behaviour of Sr compositions in G. bulloides and C. wuellerstorfi may indicate that whilst the planktonic foraminifera should reproduce very closely the seawater composition, the benthic organisms should, in addition to the major role of seawater, also be affected by some sort of interaction with the sediments. As such, planktonic foraminifera are probably more reliable indicators of seawater composition in studies involving very small periods and corresponding very slight variations of the 87Sr/86Sr ratios. Taking into account that G. bulloides is a common planktonic species (living mostly in the first 50m of the water column), whose tests seem to be in equilibrium with sea water composition, variations in its 87Sr/86Sr ratios can be related with changes in the chemical composition of the water of the Atlantic Ocean off NW Iberian Margin. The highest 87Sr/86Sr values are contemporaneous with a period of low sea level (about -140 m; Dias et al., 2000) during the LGM. According to Dias et al. (2000) at 18 ka BP the shoreline was close to the shelf break. The summital parts of the Gerês and Estrela mountains were covered by local glaciers and close to the coast freezing occurred frequently. The river catchments, which extended far to the shelf, received more rainfall due to a longer, compared to present day conditions, wet season, which promoted both physical and chemical weathering. Higher pluviosity combined with the effect of spring ice melting maintained high river discharge and consequently caused very important sediment supply to the coastal zone. The extremely narrow shelf was a very energetic environment due to sea bottom inclination and very limited long wave refraction. Therefore, at that time, a long wet season and very competent rivers should have caused important erosion of the Variscan basement in NW Iberia. Additionally, then, the shoreline was much closer to the KC 024-19 site. The combination of all these factors favoured an important deposition of terrigenous sediments and the local slight enrichment in radiogenic Sr of the seawater. With sea level rise, after the deglaciation and during the Holocene, the river estuaries became progressively far away from the shelf break. Their competence of transport also became progressively reduced and the offshore transport of detrital sediments became progressively lower. Conversely the biogenic carbonate proportion in the sediments increased, due to lower dilution by the terrigenous particles. Simultaneously, the values of 87Sr/86Sr in the seawater at the KC 024-19 site became lower, as a consequence of a complete homogenization with the ocean global composition, which was now more effective with the increasing distance towards shoreline

A multivariate randomized controlled experiment about the effects of mindfulness priming on EEG neurofeedback self-regulation serious games

Neurofeedback training (NFT) is a technique often proposed to train brain activity SR with promising results. However, some criticism has been raised due to the lack of evaluation, reliability, and validation of its learning effects. The current work evaluates the hypothesis that SR learning may be improved by priming the subject before NFT with guided mindfulness meditation (MM). The proposed framework was tested in a two-way parallel-group randomized controlled intervention with a single session alpha NFT, in a simplistic serious game design. Sixty-two healthy naïve subjects, aged between 18 and 43 years, were divided into MM priming and no-priming groups. Although both the EG and CG successfully attained the up-regulation of alpha rhythms (F(1,59) = 20.67, p ηp2 = 0.26), the EG showed a significantly enhanced ability (t(29) = 4.38, p t(29) = 1.18, p > 0.1). Furthermore, EG superior performance on NFT seems to be explained by the subject’s lack of awareness at pre-intervention, less vigour at post-intervention, increased task engagement, and a relaxed non-judgemental attitude towards the NFT tasks. This study is a preliminary validation of the proposed assisted priming framework, advancing some implicit and explicit metrics about its efficacy on NFT performance, and a promising tool for improving naïve “users” self-regulation ability.This work is co-financed by the ERDF—European Regional Development Fund through the Operational Program for Competitiveness and Internationalisation—COMPETE 2020 (ref.: POCI01-0145-FEDER-007043; ref: POCI-01-0145-FEDER-007038), the North Portugal Regional Operational Program—NORTE 2020 (ref.: NORTE-01-0145-FEDER-000045) and by the Portuguese Foundation for Science and Technology – FCT under MIT Portugal (author Ph.D. grant ref.: PD/BD/114033/2015) and within the R&D Units Project Scope (ref.: UIDB/00319/2020)

Mycobiota and mycotoxins present in finished fish feeds from farms in the Rio de Janeiro State, Brazil

The aim of the present study was to determine species of the fungal genera Aspergillus, Fusarium, and Penicillium and fumonisin B1 (FB1), aflatoxin B1 (AFB1), and ochratoxin A (OTA) contamination from feed intended for fish farms. A total of 60 samples were sampled from tilapia farms in the Rio de Janeiro State, Brazil. The quantitative enumeration of fungi as colony-forming units per gram of feed (CFU/g) was performed using the surface spread method in different culture media. The results were expressed as fungal isolation frequency and relative density. Fungal total counts ranged from <1 × 102 to 4.7 × 104 CFU/g. Fusarium counts were not observed. Among toxigenic genera, Aspergillus (68%) was the most prevalent, followed by Penicillium species (60%). Aspergillus niger aggregate (36%), Aspergillus flavus (35%), and Penicillium citrinum (71%) were the most prevalent species. A high percentage of samples (98%) were contaminated with FB1 levels, while 55% and 3.3% were contaminated with AFB1 and OTA, respectively. The simultaneous occurrence of these mycotoxins emphasizes the need for further research in the area to better assess the risk to the health of fish farms and their implications for the health of consumers of this meat.Fil: Barbosa, Tatiana S.. Universidade Federal Rural do Rio de Janeiro ; BrasilFil: Pereyra, Carina Maricel. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Microbiología e Inmunología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Soleiro, Carla A.. Universidade Federal Rural do Rio de Janeiro ; Brasil. Conselho Nacional de Desenvolvimiento Científico y Tecnológico; BrasilFil: Dias, Erica O.. Universidade Federal Rural do Rio de Janeiro ; BrasilFil: Oliveira, Aguida A.. Universidade Federal Rural do Rio de Janeiro ; Brasil. Conselho Nacional de Desenvolvimiento Científico y Tecnológico; BrasilFil: Keller, Kelly M.. Universidade Federal Rural do Rio de Janeiro ; Brasil. Conselho Nacional de Desenvolvimiento Científico y Tecnológico; BrasilFil: Silva, Pedro P. O.. Universidade Federal Rural do Rio de Janeiro; BrasilFil: Cavaglieri, Lilia Reneé. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Microbiología e Inmunología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rosa, Carlos Alberto da Rocha. Universidade Federal Rural do Rio de Janeiro ; Brasil. Conselho Nacional de Desenvolvimiento Científico y Tecnológico; Brasi

Seleção de linhagens experimentais de soja para características agronômicas e tolerância a insetos.

Esta pesquisa visou avaliar linhagens experimentais de soja, com a finalidade de identificar genótipos que reúnam características de alta produtividade e tolerância a insetos. O material foi composto por três populações obtidas de um dialelo parcial 4 x 4 envolvendo quatro genitores tolerantes a insetos e quatro cultivares de elevada produtividade. Foram conduzidos 24 experimentos no delineamento aleatório, em blocos com duas repetições subdivididas em conjuntos experimentais com testemunhas comuns, combinando as três populações e oito ambientes. Com base na produtividade de grãos, concluiu-se que: existe variabilidade genética remanescente entre as linhagens nas três populações; o manejo diferenciado com controle intensivo de insetos e controle ecológico de insetos (CII vs. CEI) é um representante eficiente de ambientes diversos; o local Anhembi destacou-se como de alta produtividade em todas as situações; para a capacidade de gerar linhagens superiores, sobressaíram-se os genitores IAC-100, D72-9601-1, BR-6, Davis e IAS-5; destaques especiais envolveram os cruzamentos do genitor IAC-100 com IAS-5, Davis, OCEPAR-4 e BR-6

A modified theory of gravity with torsion and its applications to cosmology and particle physics

In this paper we consider the most general least-order derivative theory of gravity in which not only curvature but also torsion is explicitly present in the Lagrangian, and where all independent fields have their own coupling constant: we will apply this theory to the case of ELKO fields, which is the acronym of the German \textit{Eigenspinoren des LadungsKonjugationsOperators} designating eigenspinors of the charge conjugation operator, and thus they are a Majorana-like special type of spinors; and to the Dirac fields, the most general type of spinors. We shall see that because torsion has a coupling constant that is still undetermined, the ELKO and Dirac field equations are endowed with self-interactions whose coupling constant is undetermined: we discuss different applications according to the value of the coupling constants and the different properties that consequently follow. We highlight that in this approach, the ELKO and Dirac field's self-interactions depend on the coupling constant as a parameter that may even make these non-linearities manifest at subatomic scales.Comment: 21 page

Milk microbial composition of Brazilian dairy cows entering the dry period and genomic comparison between Staphylococcus aureus strains susceptible to the bacteriophage vB_SauM-UFV_DC4

Brazil has the second-largest dairy cattle herd in the world, and bovine mastitis still can cause significant losses for dairy farmers. Despite this fact, little information is available about milk microbial composition of Brazilian dairy cows, as well as the potential use of bacteriophages in the control of S. aureus. Here, we investigated milk bacterial composition of 28 Holstein Fresian cows (109 teats), selected in the dry-off period, using 16S rRNA analysis. Furthermore, a representative S. aureus strain (UFV2030RH1) was obtained at drying-off for isolation of a bacteriophage (vB_SauM-UFV_DC4, UFV_DC4) and bacterial genomic comparison purposes. Our outcomes revealed that Staphylococcus was the third most prevalent genus and positively correlated with subclinical mastitis events. As a major finding, genomic analyses showed the presence of adhesive matrix molecules that recognize microbial surface components (MSCRAMM) in UFV2030RH1 and might indicate great biofilm formation capability. A minimum inhibitory concentration (MIC) assay showed that resistance to ampicillin was the highest among the antibiotic tested in S. aureus 3059 and UFV2030RH1, displaying values four and sixteen times greater than MIC resistance breakpoint, respectively. Together, our results suggest that Staphylococcus is highly prevalent in dairy cows at drying-off and the use of the phage UFV_DC4 as a biocontrol agent must be investigated in future studies

Measurements of CO2 exchange over a woodland savanna (Cerrado Sensu stricto) in southeast Brasil.

The technique of eddy correlation was used to measure the net ecosystem exchange over a woodland savanna (Cerrado Sensu stricto) site (Gleba Pé de Gigante) in southeast Brazil. The data set included measurements of climatological variables and soil respiration using static soil chambers. Data were collected during the period from 10 October 2000 to 30 March 2002. Measured soil respiration showed average values of 4.8 molCO m-2s-1 year round. Its 2 seasonal differences varied from 2 to 8 molCO m-2s-1 (Q = 4.9) during the dry (April to August) and wet season, respectively, and was concurrent with soil temperature and moisture variability. The net ecosystem CO2 flux (NEE) variability is controlled by solar radiation, temperature and air humidity on diel course. Seasonally, soil moisture plays a strong role by inducing litterfall, reducing canopy photosynthetic activity and soil respiration. The net sign of NEE is negative (sink) in the wet season and early dry season, with rates around -25 kgC ha-1day-1, and values as low as 40 kgC ha- 1day-1. NEE was positive (source) during most of the dry season, and changed into negative at the onset of rainy season. At critical times of soil moisture stress during the late dry season, the ecosystem experienced photosynthesis during daytime, although the net sign is positive (emission). Concurrent with dry season, the values appeared progressively positive from 5 to as much as 50 kgC ha-1day-1. The annual NEE sum appeared to be nearly in balance, or more exactly a small sink, equal to 0.1 0.3 tC ha-1yr-1, which we regard possibly as a realistic one, giving the constraining conditions imposed to the turbulent flux calculation, and favourable hypothesis of succession stages, climatic variability and CO2 fertilization

The response of benthic foraminifera to pollution and environmental stress in Ria de Aveiro (N Portugal)

This work evaluates the quality of the sediment in Ria de Aveiro, a coastal lagoon located at N of Portugal that is under strong anthropic influence, and the effects of the contamination on benthic foraminifera. The initial approach for measuring pollution was done through the load pollution index (LPI), based on As, Cd, Cr, Cu, Ni, Pb and Zn concentrations, and determined by total digestion of the sediments (TDS). This information was complemented by conducting a metal fractionation technique (sequential chemical extraction - SCE) in some of the most contaminated samples in order to define the relevance of different metal bearing- phases (exchangeable cations adsorbed by clay and co-precipitated with carbonates, absorbed by organic matter and retained in the mineralogical phase) and to evaluate the toxic heavy metal availability. Multivariable statistical analyses were carried out taking into consideration the geochemical results, as well as the biotic (percentage of species/groups of species; foraminifer abundance and diversity) and abiotic variables, such as sediment content in mud, total organic carbon (TOC) and Eh. SCE results show that most of the element concentration in the sediments is retained in the resistant mineralogical phase. However, the higher bioavailability of some toxic elements, such as As, Cd, Cu, Hg, Ni, Pb and Zn, found in Laranjo Bay, Aveiro City, Aveiro Harbours and Espinheiro Channel, have a generic negative impact on benthic foraminifera of the Aveiro lagoon. Differential sensitivity of benthic foraminifera to high concentrations of heavy metals may exist. quinqueloculina seminulum, for instance, seems to be more tolerant to higher bioavailable concentrations of Pb and Cu than Ammonia tepida or Haynesina germanica. Both species were previously considered to be the most heavy metal-tolerant foraminifer species. This study confirmed the use of benthic foraminifera as an important tool for the evaluation of the environmental quality of an ecosystem and for monitoring and restoring it.FCT (Portugal) [POCTI/ECM/59958/2004]; Geobiotec Research Centre, of Aveiro Universit