Browsing by Issue Date, starting with "2018-08"
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- Olive mild mosaic virus coat protein and p6 are suppressors of RNA silencing and their silencing confers resistance against OMMVPublication . Varanda, Carla M. R.; Materatski, Patrick; Campos, Maria Doroteia; Clara, Maria Ivone E.; Nolasco, Gustavo; Felix, Maria do RosarioRNA silencing is an important defense mechanism in plants, yet several plant viruses encode proteins that suppress this mechanism. In this study, the genome of the Olive mild mosaic virus (OMMV) was screened for silencing suppressors. The full OMMV cDNA and 5 OMMV open reading frames (ORFs) were cloned into the Gateway binary vector pK7WG2, transformed into Agrobacterium tumefaciens, and agroinfiltrated into N. benthamiana 16C plants. CP and p6 showed suppressor activity, with CP showing significantly higher activity than p6, yet activity that was lower than the full OMMV, suggesting a complementary action of CP and p6. These viral suppressors were then used to induce OMMV resistance in plants based on RNA silencing. Two hairpin constructs targeting each suppressor were agroinfiltrated in N. benthamiana plants, which were then inoculated with OMMV RNA. When silencing of both suppressors was achieved, a significant reduction in viral accumulation and symptom attenuation was observed as compared to those of the controls, as well as to when each construct was used alone, proving them to be effective against OMMV infection. This is the first time that a silencing suppressor was found in a necrovirus, and that two independent proteins act as silencing suppressors in a virus member of the Tombusviridae family.
- A thyroid hormone regulated asymmetric responsive centre is correlated with eye migration during flatfish metamorphosisPublication . Campinho, Marco António; Silva, Nádia; Martins, Gabriel G.; Anjos, Liliana; Florindo, Claudia; Roman-Padilla, Javier; Garcia-Cegarra, Ana; Louro, Bruno; Manchado, Manuel; Power, DeborahFlatfish metamorphosis is a unique post-embryonic developmental event in which thyroid hormones (THs) drive the development of symmetric pelagic larva into asymmetric benthic juveniles. One of the eyes migrates to join the other eye on the opposite side of the head. Developmental mechanisms at the basis of the acquisition of flatfish anatomical asymmetry remain an open question. Here we demonstrate that an TH responsive asymmetric centre, determined by deiodinase 2 expression, ventrally juxtaposed to the migrating eye in sole (Solea senegalensis) correlates with asymmetric cranial ossification that in turn drives eye migration. Besides skin pigmentation that is asymmetric between dorsal and ventral sides, only the most anterior head region delimited by the eyes becomes asymmetric whereas the remainder of the head and organs therein stay symmetric. Sub-ocular ossification is common to all flatfish analysed to date, so we propose that this newly discovered mechanism is universal and is associated with eye migration in all flatfish.
- Does Aortic Valve replacement surgery improve patients' Quality of Life?Publication . Coelho, Pedro; Ferreira, Lara; Vital, Clara; Fragata, JoséIntroduction: Aortic valve replacement surgery is done to increase patients' life expectancy and improve their health-related quality of life. Several published studies have found improvement in health-related quality of life after this procedure, but none have involved patients in Portugal. This study sought to evaluate patients' health-related quality of life after the implantation of aortic prostheses and compare these values with preoperative health-related quality of life and the general Portuguese population's health-related quality of life. Material and Methods: A retrospective study was done with elective patients who underwent implantation of an aortic prosthesis between August 2011 and April 2016. Health-related quality of life was evaluated using the Short Form 36 Health Survey and Short Form 6 Health Survey questionnaires in the preoperative period and 3, 6 and 12 months post-surgery. Descriptive and inferential analyses were conducted to process the data and compare preoperative health-related quality of life with postoperative values and the Portuguese population's norms. Results: The sample included 506 patients with an average age of 70.6 years. The majority are male (53.6%). The postoperative results show a statistically significant improvement compared to preoperative health-related quality of life in all eight dimensions of the Short Form 36 Health Survey. When contrasted with the general Portuguese population, patients' health-related quality of life is lower in the preoperative period, improving postoperatively and reaching higher than average health-related quality of life levels in some subgroups of patients and in various dimensions. An analysis of the Short Form 6 Health Survey results revealed that the patients undergoing this surgery have a higher level of preoperative problems compared with the general population, but these patients' values approach those of the general population by the end of one year post-surgery. Discussion: This is the first study in Portugal that compares health-related quality of life using a validated scale, before and after the aortic prosthesis implantation surgery. The results demonstrate a significant improvement in all dimensions, which is not consistently observed in other published studies. Conclusion: The results confirm that the implantation of aortic prostheses improves patients' health-related quality of life, over time bringing it close to the general population's levels.
- N,N '-dimethyl-N,N '-dicyclohexylsuccinamide: A novel molecule for the separation and recovery of Pd(II) by liquid-liquid extractionPublication . Costa, Maria Clara; Assunção, Ana; Almeida, Rúben; Rosa da Costa, Ana; Nogueira, Carlos; Paiva, Ana PaulaN,N'-dimethyl-N,N'-dicyclohexylsuccinamide (DMDCHSA) is investigated as a potential molecule for the liquid-liquid extraction of Pd(II) from chloride solutions for the first time. The effect of several parameters on Pd(II) extraction, such as the contact period between both phases, hydrochloric acid, extractant and hydrogen ion concentrations, is evaluated. Pd(II) extraction equilibrium is very fast (30 s) and the extraction percentage (%E) increases with the HCI concentration in the aqueous phases, being higher than 60% for [HCl] > 5 M. The loading capacity of DMDCHSA for Pd(II) is reasonable (molar ratio extractant/metal higher than 16). Several stripping agents (e.g. distilled water, 1 M HCl, seawater and 20 g/L chloride solution as NaCl) were successfully used to transfer Pd(II) to a new aqueous phase, and data obtained from five successive extraction-stripping cycles suggest a good DMDCHSA stability pattern. Attempts to replace 1,2-dichloroethane (1,2-DCE) by commercial and more environmentally friendly diluents showed much worse %E for Pd(II). Selectivity tests with binary, ternary and more complex metal ion solutions were carried out to evaluate the performance of DMDCHSA towards Pd(II) recovery from 6 M HCl, when in presence of Pt(IV), Fe(III), Zn(II), Al(III) and Ce(III), metal ions usually present in solutions that may result from the hydrometallurgical treatment of spent automobile catalytic converters. It was generally observed that the additional metal ions do not affect the recovery of Pd(II) by DMDCHSA, although Fe(III) and Pt(IV) were co-extracted in a great extent. A solvent extraction (SX) scheme is proposed, based on a previous separation of Fe(III) with tributylphosphate (TBP) and on the selective and sequential stripping of Pt(IV) and Pd(II) from the loaded DMDCHSA with 0.01 M thiourea in 0.5 M HCI and seawater, respectively. The dependence of the Pd(II) distribution ratios on DMDCHSA and acidity, complemented with UV-Visible spectroscopy data, points out to DMDCHSA:Pd(II) extracted species with a 2:1 molar ratio and suggests the occurrence of an outer-sphere ion pair reaction, in which both [PdCl4](2-) and HCI are extracted.
- A high-precision liDAR-based method for surveying and classifying coastal notchesPublication . Terefenko, Pawel; Wziatek, Dagmara Zelaya; Dalyot, Sagi; Boski, T.; Lima-Filho, Francisco PinheiroFormation of notches is an important process in the erosion of seaside cliffs. Monitoring of coastal notch erosion rate and processes has become a prime research focus for many coastal geomorphologists. Observation of notch erosion rate considers a number of characteristics, including cliff collapse risk, distinction of historical sea levels, and recognition of ongoing erosional mechanisms. This study presents new approaches for surveying and classifying marine notches based on a high-precision light detection and ranging (LiDAR)-based experiment performed on a small region of a coastal cliff in southern Portugal. A terrestrial LiDAR scanner was used to measure geometrical parameters and surface roughness of selected notches, enabling their classification according to shape and origin. The implemented methodology proved to be a highly effective tool for providing an unbiased analysis of marine morphodynamic processes acting on the seaside cliffs. In the analyzed population of voids carved into Miocene calcarenites in a coastal cliff section, two types of notch morphology were distinguished, namely U-shaped and V-shaped. The method presented here provides valuable data for landscape evaluation, sea-level changes, and any other types of analyses that rely on the accurate interpretation of cliff morphological features.
- Cultura e literatura: intervençõesPublication . Carvalho, João Carlos Firmino Andrade deReúnem-se, neste livro, algumas intervenções (conferências, palestras, apresentações) que o Autor foi fazendo ao longo do tempo e que teriam ficado esquecidas se não fossem agora disponibilizadas ao Leitor: trata- -se de reflexões sobre identidade e alteridade ao longo da nossa história colectiva, sobre ciência e retórica no século XVI, sobre a poesia de Camões, sobre a célebre narrativa de viagem de Fernão Mendes Pinto, sobre certa retórica panfletária seiscentista, sobre o conceito de romance histórico, sobre a escrita poética de Raul de Carvalho, sobre o ensaio acerca da obra de Fernão Mendes Pinto da autoria de António Rosa Mendes, sobre a escritora Inês Pedrosa, sobre o romance A Profecia – Asura de António Costeira. Todos estas intervenções corresponderam a momentos de comunhão colectiva e de interesse partilhado em torno da cultura e da literatura, momentos esses que agora se alargam a um público leitor mais abrangente, mas – assim o esperamos – igualmente interessado nas matérias atrás enunciadas.
- Decoding a cancer-relevant splicing decision in the RON proto-oncogene using high-throughput mutagenesisPublication . Braun, Simon; Enculescu, Mihaela; Setty, Samarth T.; Cortes-Lopez, Mariela; Almeida, Bernardo; Sutandy, F. X. Reymond; Schulz, Laura; Busch, Anke; Seiler, Markus; Ebersberger, Stefanie; Barbosa-Morais, Nuno L.; Legewie, Stefan; Konig, Julian; Zarnack, KathiMutations causing aberrant splicing are frequently implicated in human diseases including cancer. Here, we establish a high-throughput screen of randomly mutated minigenes to decode the cis-regulatory landscape that determines alternative splicing of exon 11 in the proto-oncogene MST1R (RON). Mathematical modelling of splicing kinetics enables us to identify more than 1000 mutations affecting RON exon 11 skipping, which corresponds to the pathological isoform RON Delta 165. Importantly, the effects correlate with RON alternative splicing in cancer patients bearing the same mutations. Moreover, we highlight heterogeneous nuclear ribonucleoprotein H (HNRNPH) as a key regulator of RON splicing in healthy tissues and cancer. Using iCLIP and synergy analysis, we pinpoint the functionally most relevant HNRNPH binding sites and demonstrate how cooperative HNRNPH binding facilitates a splicing switch of RON exon 11. Our results thereby offer insights into splicing regulation and the impact of mutations on alternative splicing in cancer.
- Global shortage of technical agars: back to basics (resource management)Publication . Santos, Rui; Melo, Ricardo A.Bacteriological and technical agars are in short supply with potential consequences for research, public health, and clinical labs around the world. To diagnose bottlenecks and sustainability problems that may be putting the industry at risk, we analyzed the available time series for the global landings of Gelidium, the most important raw materials for the industry. Data on the harvest of Gelidium spp. have been reported since1912, when Japan was the only producer. After World War II the diversification of harvested species and producing countries resulted in a strong increase in global landings. Maximum harvest yields of almost 60,000 t year(-1) in the 1960s were sustained until the 1980s, after which landings decreased continuously to the present. In the 2010s, a reduction in the global production to about 25,000 t year(-1) was observed, which was lower than the yields of the 1950s. Landings by important producers such as Japan, Korea, Spain, and Portugal have collapsed. This is the ultimate cause of the present shortage of bacteriological and technical agars. However, an important factor at play is the concentration of the global landings of Gelidium in Morocco, as its relative contribution increased from 23% in the 1960s to the present 82%. Two specific bottlenecks were identified: restrictive export quotas of unprocessed Gelidium in favor of the national agar industry and resource management regulations that were apparently not enforced resulting in over-harvesting and resource decline. The global industry may well be dependent on resource management basics. Simple harvest statistics must be gathered such as the harvest effort and the variation of harvest yields along the harvest season. We discuss how this information is fundamental to manage the resource. The available harvest statistics are generally poor and limited and vary significantly among different sources of data. Probable confusions between dry and wet weight reporting and poor discrimination of the species harvested need to be resolved.
- Individual-based genetic analyses support asexual hydrochory dispersal in Zostera nolteiPublication . Berković, Buga; Coelho, Nelson; Gouveia, Licínia; Serrao, Ester; Alberto, FilipeDispersal beyond the local patch in clonal plants was typically thought to result from sexual reproduction via seed dispersal. However, evidence for the separation, transport by water, and re-establishment of asexual propagules (asexual hydrochory) is mounting suggesting other important means of dispersal in aquatic plants. Using an unprecedented sampling size and microsatellite genetic identification, we describe the distribution of seagrass clones along tens of km within a coastal lagoon in Southern Portugal. Our spatially explicit individual-based sampling design covered 84 km(2) and collected 3 185 Zostera noltei ramets from 803 sites. We estimated clone age, assuming rhizome elongation as the only mechanism of clone spread, and contrasted it with paleo-oceanographic sea level change. We also studied the association between a source of disturbance and the location of large clones. A total of 16 clones were sampled more than 10 times and the most abundant one was sampled 59 times. The largest distance between two samples from the same clone was 26.4 km and a total of 58 and 10 clones were sampled across more than 2 and 10 km, respectively. The number of extremely large clone sizes, and their old ages when assuming the rhizome elongation as the single causal mechanism, suggests other processes are behind the span of these clones. We discuss how the dispersal of vegetative fragments in a stepping-stone manner might have produced this pattern. We found higher probabilities to sample large clones away from the lagoon inlet, considered a source of disturbance. This study corroborates previous experiments on the success of transport and re-establishment of asexual fragments and supports the hypothesis that asexual hydrochory is responsible for the extent of these clones.
- The new medical licensing examination in Portugal: A gigantic millimeter leapPublication . Ponte, JoséAcho que a classe médica está de parabéns por finalmente ter sido abandonada uma PNS largamente desacreditada. A meu ver, passou-se de uma máquina a vapor para um motor de combustão interna, alimentado através de um carburador e ligado às rodas através de uma caixa manual de três velocidades. Uma pena, dado que os carros híbridos e elétricos já estão no mercado há anos. O que quero dizer é que, ao fazer a mudança, perdeu- -se uma oportunidade única de saltarmos para o século XXI.