Browsing by Issue Date, starting with "2017-12"
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- The climate of the Common Era off the Iberian PeninsulaPublication . Abrantes, Fatima; Rodrigues, Teresa; Rufino, Marta; Salgueiro, Emilia; Oliveira, Dulce; Gomes, Sandra; Oliveira, Paulo; Costa, Ana; Mil-Homens, Mario; Drago, Teresa; Naughton, FilipaThe Mediterranean region is a climate hot spot, sensitive not only to global warming but also to water availability. In this work we document major temperature and precipitation changes in the Iberian Peninsula and margin during the last 2000 years and propose an interplay of the North Atlantic internal variability with the three atmospheric circulation modes (ACMs), (North Atlantic Oscillation (NAO), east atlantic (EA) and Scandinavia (SCAND)) to explain the detected climate variability. We present reconstructions of sea surface temperature (SST derived from alkenones) and on-land precipitation (estimated from higher plant n-alkanes and pollen data) in sedimentary sequences recovered along the Iberian Margin between the south of Portugal (Algarve) and the northwest of Spain (Galiza) (36 to 42 degrees N). A clear long-term cooling trend, from 0 CE to the beginning of the 20th century, emerges in all SST records and is considered to be a reflection of the decrease in the Northern Hemisphere summer insolation that began after the Holocene optimum. Multi-decadal/centennial SST variability follows other records from Spain, Europe and the Northern Hemisphere. Warm SSTs throughout the first 1300 years encompass the Roman period (RP), the Dark Ages (DA) and the Medieval Climate Anomaly (MCA). A cooling initiated at 1300 CE leads to 4 centuries of colder SSTs contemporary with the Little Ice Age (LIA), while a climate warming at 1800 CE marks the beginning of the modern/Industrial Era. Novel results include two distinct phases in the MCA: an early period (900-1100 years) characterized by intense precipitation/flooding and warm winters but a cooler spring-fall season attributed to the interplay of internal oceanic variability with a positive phase in the three modes of atmospheric circulation (NAO, EA and SCAND). The late MCA is marked by cooler and relatively drier winters and a warmer spring-fall season consistent with a shift to a negative mode of the SCAND. The Industrial Era reveals a clear difference between the NW Iberia and the Algarve records. While off NW Iberia variability is low, the Algarve shows large-amplitude decadal variability with an inverse relationship between SST and river input. Such conditions suggest a shift in the EA mode, from negative between 1900 and 1970 CE to positive after 1970, while NAO and SCAND remain in a positive phase. The particularly noticeable rise in SST at the Algarve site by the mid-20th century (+/- 1970), provides evidence for a regional response to the ongoing climate warming. The reported findings have implications for decadal-scale predictions of future climate change in the Iberian Peninsula.
- BINK: Biological binary keypoint descriptorPublication . Saleiro Filho, Mario; Terzic, Kasim; Rodrigues, João; du Buf, J. M. H.Learning robust keypoint descriptors has become an active research area in the past decade. Matching local features is not only important for computational applications, but may also play an important role in early biological vision for disparity and motion processing. Although there were already some floatingpoint descriptors like SIFT and SURF that can yield high matching rates, the need for better and faster descriptors for real-time applications and embedded devices with low computational power led to the development of binary descriptors, which are usually much faster to compute and to match. Most of these descriptors are based on purely computational methods. The few descriptors that take some inspiration from biological systems are still lagging behind in terms of performance. In this paper, we propose a new biologically inspired binary keypoint descriptor: SINK. Built on responses of cortical V1 cells, it significantly outperforms the other biologically inspired descriptors. The new descriptor can be easily integrated with a V1-based keypoint detector that we previously developed for real-time applications. (C) 2017 Elsevier B.V. All rights reserved.
- Oestrogen receptor distribution related to functional thymus anatomy of the European sea bass, Dicentrarchus labraxPublication . Paiola, Matthieu; Knigge, Thomas; Picchietti, Simona; Duflot, Aurelie; Guerra, Laura; Pinto, Patricia IS; Scapigliati, Giuseppe; Monsinjon, TiphaineIn jawed vertebrates, the crosstalk between immune and endocrine system as well as many fundamental mechanisms of T cell development are evolutionary conserved. Oestrogens affect mammalian thymic function and plasticity, but the mechanisms of action and the oestrogen receptors involved remain unclear. To corroborate the oestrogenic regulation of thymic function in teleosts and to identify the implicated oestrogen receptor subtypes, we examined the distribution of nuclear and membrane oestrogen receptors within the thymus of the European Sea bass, Dicentrarchus labrax, in relation to its morpho-functional organisation. Immunohistological analysis specified thymus histology and organisation in teleosts and described, for the first time, Hassall's corpuscle like structures in the medulla of sea bass. All oestrogen receptors were expressed at the transcript and protein level, both in T cells and in stromal cells belonging to specific functional areas. These observations suggest complex regulatory actions of oestrogen on thymic function, notably through the stromal microenvironment, comprising both, genomic and non-genomic pathways that are likely to affect T cell maturation and trafficking processes. Comparison with birds, rodents and humans supports the thymic localization of oestrogen receptors and suggests that oestrogens modulate T cell maturation in all gnathostomes. (C) 2017 Elsevier Ltd. All rights reserved.
- Antioxidant activity and protective effect of bee bread (honey and pollen) in aluminum-induced anemia, elevation of inflammatory makers and hepato-renal toxicityPublication . Bakour, Meryem; Al-Waili, Noori S.; El Menyiy, Nawal; Imtara, Hamada; Figueira, A.C.; Al-Waili, Thia; Lyoussi, BadiaaAluminum toxicity might be related to oxidative stress, and the antioxidant activity and protective effect of bee bread, which contains pollen, honey and bees' enzymes, on aluminum induced blood and hepato-renal toxicity was investigated in rats. Chemical analysis and antioxidant capacity of bee bread were conducted. The animal experiment in rats included; group 1: received distilled water (10 ml/kg b.wt), group 2: received aluminum chloride (662.2 mg/kg b.wt), group 3: received aluminum chloride (662.2 mg/kg b.wt) and ethanolic extract of the bee bread (500 mg/kg b.wt), and group 4: received aluminum chloride (662.2 mg/kg b.wt) and ethanolic extract of the bee bread (750 mg/kg b.wt). Doses were given once daily via a gavage. C-reactive protein, transaminases, urea, creatinine, creatinine clearance, sodium and potassium and urine sodium and potassium were determined on day 28 of the experiment. Bee bread contained protein, fat, fiber, ash, carbohydrate, phenol and flavonoids and it exhibited antioxidant activity. Aluminum caused a significant elevation of blood urea, transaminase, C-reactive protein and monocyte count and significantly decreased hemoglobin. These changes were significantly ameliorated by the use of bee bread. Bee bread has an antioxidant property, and exhibited a protective effect on aluminum induced blood and hepato-renal toxicity and elevation of inflammatory markers C-reactive protein, leukocyte and monocyte counts.
- FOXO transcription factors at the interface of metabolism and cancerPublication . Link, Wolfgang; Fernandez-Marcos, Pablo J.Diabetes refers to a group of metabolic diseases characterized by impaired insulin signalling and high blood glucose. A growing body of epidemiological evidence links diabetes to several types of cancer but the underlying molecular mechanisms are poorly understood. The signalling cascade connecting insulin and FOXO proteins provides a compelling example for a conserved pathway at the interface between insulin signalling and cancer. FOXOs are transcription factors that orchestrate programs of gene expression known to control a variety of processes in response to cellular stress. Genes regulated by this family of proteins are involved in the regulation of cellular energy production, oxidative stress resistance and cell viability and proliferation. Accordingly, FOXO factors have been shown to play an important role in the suppression of tumour growth and in the regulation of metabolic homeostasis. There is emerging evidence that deregulation of FOXO factors might account for the association between insulin resistance-related metabolic disorders and cancer.
- Comparative metagenomics reveals the distinctive adaptive features of the Spongia officinalis endosymbiotic consortiumPublication . Karimi, Elham; Ramos, Miguel; Gonçalves, Jorge Manuel Santos; Xavier, Joana R.; Reis, Margarida; Costa, RodrigoCurrent knowledge of sponge microbiome functioning derives mostly from comparative analyses with bacterioplankton communities. We employed a metagenomics-centered approach to unveil the distinct features of the Spongia officinalis endosymbiotic consortium in the context of its two primary environmental vicinities. Microbial metagenomic DNA samples (n = 10) from sponges, seawater, and sediments were subjected to Hiseq Illumina sequencing (c. 15 million 100 bp reads per sample). Totals of 10,272 InterPro (IPR) predicted protein entries and 784 rRNA gene operational taxonomic units (OTUs, 97% cut-off) were uncovered from all metagenomes. Despite the large divergence in microbial community assembly between the surveyed biotopes, the S. officinalis symbiotic community shared slightly greater similarity (p < 0.05), in terms of both taxonomy and function, to sediment than to seawater communities. The vast majority of the dominant S. officinalis symbionts (i.e., OTUs), representing several, so-far uncultivable lineages in diverse bacterial phyla, displayed higher residual abundances in sediments than in seawater. CRISPR-Cas proteins and restriction endonucleases presented much higher frequencies (accompanied by lower viral abundances) in sponges than in the environment. However, several genomic features sharply enriched in the sponge specimens, including eukaryotic-like repeat motifs (ankyrins, tetratricopeptides, WD-40, and leucine-rich repeats), and genes encoding for plasmids, sulfatases, polyketide synthases, type IV secretion proteins, and terpene/terpenoid synthases presented, to varying degrees, higher frequencies in sediments than in seawater. In contrast, much higher abundances of motility and chemotaxis genes were found in sediments and seawater than in sponges. Higher cell and surface densities, sponge cell shedding and particle uptake, and putative chemical signaling processes favoring symbiont persistence in particulate matrices all may act as mechanisms underlying the observed degrees of taxonomic connectivity and functional convergence between sponges and sediments. The reduced frequency of motility and chemotaxis genes in the sponge microbiome reinforces the notion of a prevalent mutualistic mode of living inside the host. This study highlights the S. officinalis "endosymbiome" as a distinct consortium of uncultured prokaryotes displaying a likely "sit-and-wait" strategy to nutrient foraging coupled to sophisticated anti-viral defenses, unique natural product biosynthesis, nutrient utilization and detoxification capacities, and both microbe-microbe and host-microbe gene transfer amenability.
- On the kernel of a singular integral operator with shiftPublication . Marreiros, RuiSome estimates for the dimension of the kernel of the singular integral operator I - cUP(+) : L-p(n)(T) -> L-p(n)(T), p is an element of (1, infinity), with a non-Carleman shift are obtained, where P+ is the Cauchy projector, U is an isometric shift operator and c(t) is a continuous matrix function on the unit circle T. It is supposed that the shift has a finite set of fixed points and all the eigenvalues of the matrix c(t) at the fixed points, simultaneously belong either to the interior of the unit circle T or to its exterior. The case of an operator with a general shift is also considered. Some relations between those estimates and the resolvent set of the operator cU are pointed out.
- Can the essential oil of Aloysia triphylla have anesthetic effect and improve the physiological parameters of the carnivorous freshwater catfish Lophiosilurus alexandri after transport?Publication . Becker, Alexssandro G.; Luz, Ronald Kennedy; Mattioli, Cristiano Campos; Nakayama, Cintia Labussiere; de Souza e Silva, Walisson; Paes Leme, Fabiola de Oliveira; Pinto de Mendonca Mendes, Helena Correa; Heinzmann, Berta Maria; Baldisserotto, BernardoThe Lophiosilurus alexandri is an important species to the Brazilian aquaculture. Moreover, the studies about the effects of essential oil (EO) of Aloysia triphylla in fish are almost absent. Thus, the aims of this study were: 1) to investigate the anesthetic effect of the EO of A. triphylla and, 2) if this EO improves the physiological parameters of L. alexandri after transport. The experiment was divided in three steps: 1) the anesthesia induction with the EO of A. triphylla (in mu L/L): 25, 50, 100, 200, or 400; 2) transport for 4 h with the fish separated into three groups: control and two EO concentrations of A. triphylla (in mu L/L): 12.5 and 25; and, 3) determination of the ventilatory frequency (VF) in fish exposed to this EO at 12.5 or 25 mu L/L. The results showed that the increasing concentration of A. triphylla EO proportionally decreased the time required for sedation and anesthesia induction and increased recovery time. After transport, some alterations in water and blood parameters were observed independently of the treatment and lower VF was found in fish exposed to 25 mu L/L of A. triphylla EO. Taken together these results indicated that this EO decreased fish metabolism. Finally, A. triphylla EO was an efficient anesthetic in L. alexandri, mainly at 400 mu L/L and, both EO concentrations used in the transport contributed to improve water and physiological parameters.
- Psychometric properties of Basic Empathy Scale among female juvenile delinquents and school youthsPublication . Pechorro, Pedro; Kahn, Rachel E.; Gonçalves, Rui Abrunhosa; Ray, James V.Research on empathy often distinguishes between affective and cognitive empathy, but there is limited knowledge regarding the application or measurement of these two dimensions of empathy among female youth, especially forensic samples of female youth. The main aim of the present study was to examine the psychometric properties of the Basic Empathy Scale (BES) among a Portuguese sample of female youths (N = 377), composed of incarcerated female juvenile offenders (n = 103) and school youths (n = 274). The two-factor structure of the BES obtained a good fit among the school sample, but the fit among the forensic sample was poor. Both samples demonstrated adequate psychometric properties in terms of Cronbach's alpha, omega coefficient, mean inter item correlations, corrected item-total correlation range, and criterion validity. However, some caution is advised when using the BES with female youth involved in the juvenile justice system, particularly with incarcerated female youth. (C) 2017 Elsevier Ltd. All rights reserved.
- Decapod larvae distribution and species composition off the southern Portuguese coastPublication . Pochelon, Patricia N.; Pires, Rita F. T.; Dubert, Jesus; Nolasco, Rita; Santos, A. Miguel P.; Queiroga, Henrique; dos Santos, AntoninaFor decapod crustaceans, the larval phase is the main responsible for dispersal, given the direct emission from adult habitats into the water column. Circulation patterns and behavioural mechanisms control the dispersal distance and connectivity between different areas. Information on larval distribution and abundance is required to predict the size and location of breeding populations, and correctly manage marine resources. Spatial distribution and abundance data of decapod larvae, and environmental parameters were assessed in winter surveys off the southern Portuguese coast. To better understand the oceanic structures driving larval distribution patterns, in situ physical parameters were measured and a hydrodynamical model used. Inter-annual, cross-shore and alongshore differences on decapod larvae distribution were found. Brachyuran crabs dominated the samples and similar taxa composition was observed in the most dynamic areas. Coastal taxa dominated the nearshore survey and were almost absent in the more offshore one, that registered much lower abundances. An upwelling front allowed a clear cross-shore species separation, also evident in the abundance values and number of taxa. Hydrodynamical conditions and adult habitats were the main factors explaining the observed patterns. Important missing information to understand the distribution patterns of decapod larval communities and the mechanisms behind them is given for the region.