In vitro plantlet production of the endangered Pinguicula vulgaris

    Get PDF
    This study describes the development of a micropropagation protocol for Pinguicula vulgaris using cultures initiated from in vitro produced seedlings. P. vulgaris is a carnivorous plant with a northern, disjunctly circumpolar distribution and specific habitat requirements, and is hence becoming increasingly rare. Shoot proliferation was significantly influenced by Murashige and Skoog (MS) macronutrient concentration, showing higher proliferation rates in 1/4MS, but was not affected by the addition of 0.1 mg/L 6-benzyladenine (BA) or zeatin (Zea). The best medium for propagating P. vulgaris was plant growth regulator (PGR) free A1/4MS. An average of 7.62 new shoots per initial explant could be obtained after 8 weeks of culture, of which over 79% produced roots during proliferation. Moreover, rooting percentages of 100% were obtained for the initial explants in all the tested media, including media without PGRs. The plantlets were successfully acclimatized to ex vitro conditions, exhibiting normal development

    Hybrid materials based on polyethylene and MCM-41 microparticles functionalized with silanes: catalytic aspects of in situ polymerization, crystalline features and mechanical properties

    Get PDF
    New nanocomposites based on polyethylene have been prepared by in situ polymerization of ethylene in presence of mesoporous MCM-41. The polymerization reactions were performed using a zirconocene catalyst either under homogenous conditions or supported onto mesoporous MCM-41 particles, which are synthesized and decorated post-synthesis with two silanes before polymerization in order to promote an enhanced interfacial adhesion. The existence of polyethylene chains able to crystallize within the mesoporous channels in the resulting nanocomposites is figured out from the small endothermic process, located at around 80 C, on heating calorimetric experiments, in addition to the main melting endotherm. These results indicate that polyethylene macrochains can grow up during polymerization either outside or inside the MCM-41 channels, these keeping their regular hexagonal arrangements. Mechanical response is observed to be dependent on the content in mesoporous MCM-41 and on the crystalline features of polyethylene. Accordingly, stiffness increases and deformability decreases in the nanocomposites as much as MCM-41 content is enlarged and polyethylene amount within channels is raised. Ultimate mechanical performance improves with MCM-41 incorporation without varying the final processing temperature

    Cherenkov-like emission of Z bosons

    Get PDF
    We study CPT and Lorentz violation in the electroweak gauge sector of the Standard Model in the context of the Standard-Model Extension (SME). In particular, we show that any non-zero value of a certain relevant Lorentz violation parameter that is thus far unbounded by experiment would imply that for sufficiently large energies one of the helicity modes of the Z boson should propagate with spacelike four-momentum and become stable against decay in vacullin. In this scenario, Cherenkov-hike radiation of Z bosons by ultra-highenergy cosmic-ray protons becomes possible. We deduce a bound on the Lorentz violation parameter from the observational data on ultra-high energy cosmic rays.Portuguese Fundacao para a Ciencia e a Tecnologia (FCT) [SFRH/BPD/101403/2014]; program POPH/FS

    Sleep promotes the extraction of grammatical rules

    Get PDF
    Grammar acquisition is a high level cognitive function that requires the extraction of complex rules. While it has been proposed that offline time might benefit this type of rule extraction, this remains to be tested. Here, we addressed this question using an artificial grammar learning paradigm. During a short-term memory cover task, eighty-one human participants were exposed to letter sequences generated according to an unknown artificial grammar. Following a time delay of 15 min, 12 h (wake or sleep) or 24 h, participants classified novel test sequences as Grammatical or Non-Grammatical. Previous behavioral and functional neuroimaging work has shown that classification can be guided by two distinct underlying processes: (1) the holistic abstraction of the underlying grammar rules and (2) the detection of sequence chunks that appear at varying frequencies during exposure. Here, we show that classification performance improved after sleep. Moreover, this improvement was due to an enhancement of rule abstraction, while the effect of chunk frequency was unaltered by sleep. These findings suggest that sleep plays a critical role in extracting complex structure from separate but related items during integrative memory processing. Our findings stress the importance of alternating periods of learning with sleep in settings in which complex information must be acquired.Dutch National Science Foundation [NWO 051-04-100]; Fundacao para a Ciencia e Tecnologia [PTDC/PSI-PCO/110734/2009]; Max Planck Institute for Psycholinguistics; Donders Institute for Brain; Cognition and Behaviour; Vetenskapsradetinfo:eu-repo/semantics/publishedVersio

    Collaborative method to maintain business process models updated

    Get PDF
    Business process models are often forgotten after their creation and its representation is not usually updated. This appears to be negative as processes evolve over time. This paper discusses the issue of business process models maintenance through the definition of a collaborative method that creates interaction contexts enabling business actors to discuss about business processes, sharing business knowledge. The collaboration method extends the discussion about existing process representations to all stakeholders promoting their update. This collaborative method contributes to improve business process models, allowing updates based in change proposals and discussions, using a groupware tool that was developed. Four case studies were developed in real organizational environment. We came to the conclusion that the defined method and the developed tool can help organizations to maintain a business process model updated based on the inputs and consequent discussions taken by the organizational actors who participate in the

    Vitamin A affects flatfish development in a thyroid hormone signaling and metamorphic stage dependent manner

    Get PDF
    Vitamin A (VA) and retinoid derivatives are known morphogens controlling vertebrate development. Despite the research effort conducted during the last decade, the precise mechanism of how VA induces post-natal bone changes, and particularly those operating through crosstalk with the thyroid hormones (THs) remain to be fully understood. Since effects and mechanisms seem to be dose and time-dependent, flatfish are an interesting study model as they undergo a characteristic process of metamorphosis driven by THs that can be followed by external appearance. Here, we studied the effects of VA imbalance that might determine Senegalese sole (Solea senegalensis) skeletogenetic phenotype through development of thyroid follicles, THs homeostasis and signaling when a dietary VA excess was specifically provided during pre-, pro-or post-metamorphic stages using enriched rotifers and Artemia as carriers. The increased VA content in enriched live prey was associated to a higher VA content in fish at all developmental stages. Dietary VA content clearly affected thyroid follicle development, T3 and T4 immunoreactive staining, skeletogenesis and mineralization in a dose and time-dependent fashion. Gene expression analysis showed that VA levels modified the mRNA abundance of VA- and TH-specific nuclear receptors at specific developmental stages. Present results provide new and key knowledge to better understand how VA and TH pathways interact at tissue, cellular and nuclear level at different developmental periods in Senegalese sole, unveiling how dietary modulation might determine juvenile phenotype and physiology.Ministry of Education and Culture (MEC) of the Spanish Government [AGL2005-02478]; [SFRH/BPD/82049/2011]info:eu-repo/semantics/publishedVersio

    Facultative secondary lecithotrophy in the megalopa of the shrimp Lysmata seticaudata (Risso, 1816) (Decapoda : Hippolytidae) under laboratory conditions

    Get PDF
    Certain decapod crustaceans can catabolize internal reserves to undergo partial or full larval development. This feature is termed secondary lecithotrophy, if energy used results from plankton derived organic matter accumulated Ig earlier larval stages. The present work reports the ability of Lysmata seticaudata megalopa to moll to the first juvenile stage in the absence of food. Unlike previous records of secondary lecithotrophy displayed by nonfeeding last larval stages of hermit crabs and spiny lobsters, the megalopa of L. seticaudata retains its feeding capacity. This is the first time such a feature has been reported in decapods, and the term facultative secondary lecithotrophy is proposed. The build up of energy reserves continues during the last zoeal stage of L. seticaudata, with starved zoea IX failing to molt to megalopa. Energy reserves that enable starved megalopa to molt to juvenile seem to be partially depleted, with starved juveniles produced either from, starved or fed megalopae being unable to molt to the next juvenile stage. The longer resistance of starved juveniles produced from fed megalopae (nine days), compared to that of starved juveniles produced from starved megalopae (five days), indicates that some energy reserves may pass to juvenile, not being totally depleted at

    Elevated seawater temperatures decrease microbial diversity in the gut of mytilus coruscus

    Get PDF
    The gut microbial community is critical for the host immune system, and in recent years, it has been extensively studied in vertebrates using 'omic' technologies. In contrast, knowledge about how the interactions between water temperature and diet affect the gut microbiota of marine invertebrates that do not thermoregulate is much less studied. In the present study, the effect of elevated seawater temperature and diet (Isochrysis zhanjiangensis and Platymonas helgolandica var. tsingtaoensis) on the gut microbial community of the commercial mussel, Mytilus coruscus, was investigated. The 16S rRNA gene sequencing was used to characterize the microbial community in M. coruscus gut. The mortality of M. coruscus exposed to a high water temperature (31 degrees C) increased after 3 days and the diversity of the bacterial community in the gut of live M. coruscus was significantly reduced. For example, the abundance of Bacteroides (Bacteroidetes) and norank_Marinilabiaceae (Bacteroidetes) increased in the gut of M. coruscus fed I. zhanjiangensis. In M. coruscus fed P. helgolandica, the abundance of Arcobacter (Proteobacteria) and norank_Marinilabiaceae increased and the abundance of unclassified_Flavobacteriaceae (Bacteroidetes) decreased. The results obtained in the present study suggest that high temperatures favored the proliferation of opportunistic bacteria, including Bacteroides and Arcobacter, which may increase host susceptibility to disease. Microbial community composition of the gut in live M. coruscus was not impacted by the microalgal diet but it was modified in the group of mussels that died. The present study provides insight into the potential effects on the gut microbiome and mussel-bacteria interactions of rising seawater temperatures.Ministry of Science and Technology of China [2016YFE0131900]; National Natural Science Foundation of China [41476131]; Peak Discipline Program for Fisheries from the Shanghai Municipal Governmen

    Response of key stress-related genes of the seagrass Posidonia oceanica in the vicinity of submarine volcanic vents

    Get PDF
    Submarine volcanic vents are being used as natural laboratories to assess the effects of increased ocean acidity and carbon dioxide (CO2) concentration on marine organisms and communities. However, in the vicinity of volcanic vents other factors in addition to CO2, which is the main gaseous component of the emissions, may directly or indirectly confound the biota responses to high CO2. Here we used for the first time the expression of antioxidant and stress-related genes of the seagrass Posidonia oceanica to assess the stress levels of the species. Our hypothesis is that unknown factors are causing metabolic stress that may confound the putative effects attributed to CO2 enrichment only. We analyzed the expression of 35 antioxidant and stress-related genes of P. oceanica in the vicinity of submerged volcanic vents located in the islands of Ischia and Panarea, Italy, and compared them with those from control sites away from the influence of vents. Reverse-transcription quantitative polymerase chain reaction (RT-qPCR) was used to characterize gene expression patterns. Fifty-one percent of genes analyzed showed significant expression changes. Metal detoxification genes were mostly down-regulated in relation to controls at both Ischia and Panarea, indicating that P. oceanica does not increase the synthesis of heavy metal detoxification proteins in response to the environmental conditions present at the two vents. The up-regulation of genes involved in the free radical detoxification response (e.g., CAPX, SODCP and GR) indicates that, in contrast with Ischia, P. oceanica at the Panarea site faces stressors that result in the production of reactive oxygen species, triggering antioxidant responses. In addition, heat shock proteins were also activated at Panarea and not at Ischia. These proteins are activated to adjust stress-accumulated misfolded proteins and prevent their aggregation as a response to some stressors, not necessarily high temperature. This is the first study analyzing the expression of target genes in marine plants living near natural CO2 vents. Our results call for contention to the general claim of seagrasses as "winners" in a high-CO2 world, based on observations near volcanic vents. Careful consideration of factors that are at play in natural vents sites other than CO2 and acidification is required. This study also constitutes a first step for using stress-related genes as indicators of environmental pressures in a changing ocean.project HighGrass "High-CO2 effects on seagrass photosynthetic ecophysiology" [PTDC/MAREST/3687/2012]; MIUR Italian flagship project RITMARE; ESF COST Action "Seagrass Productivity: from genes to ecosystem management

    Improved production of lutein and β-carotene by thermal and light intensity upshifts in the marine microalga Tetraselmis sp. CTP4

    Get PDF
    The industrial microalga Tetraselmis sp. CTP4 is a promising candidate for aquaculture feed, novel food, cosmeceutical and nutraceutical due to its balanced biochemical profile. To further upgrade its biomass value, carotenogenesis was investigated by testing four environmental factors, namely temperature, light intensity, salinity and nutrient availability over different growth stages. The most important factor for carotenoid induction in this species is a sufficient supply of nitrates leading to an exponential growth of the cells. Furthermore, high temperatures of over 30 degrees C compared to lower temperatures (10 and 20 degrees C) induced the accumulation of carotenoids in this species. Remarkably, the two different branches of carotenoid synthesis were regulated depending on different light intensities. Contents of beta-carotene were 3-fold higher under low light intensities (33 mu mol m(-2) s(-1)) while lutein contents increased 1.5-fold under higher light intensities (170 and 280 mu mol m(-2) s(-1)). Nevertheless, highest contents of carotenoids (8.48 +/- 0.47 mg g(-1) DW) were found upon a thermal upshift from 20 degrees C to 35 degrees C after only two days at a light intensity of 170 mu mol m(-2) s(-1). Under these conditions, high contents of both lutein and beta-carotene were reached accounting for 3.17 +/- 0.18 and 3.21 +/- 0.18 mg g(-1) DW, respectively. This study indicates that Tetraselmis sp. CTP4 could be a sustainable source of lutein and beta-carotene at locations where a robust, euryhaline, thermotolerant microalgal strain is required.Funding Agency Portuguese Foundation for Science and Technology UID/Multi/04326/2019 SFRH/BD/115325/2016 SFRH/BD/140143/2018 SFRH/BD/105541/2014 0055 ALGARED+ 05 INTERREG V-A -Espana Portugal project national Portuguese funding PPBI-POCI-01-0145-FEDER-22122 Nord Universityinfo:eu-repo/semantics/publishedVersio
    Sapientiais based in PT
    Access Repository Dashboard
    Do you manage Sapientia? Access insider analytics, issue reports and manage access to outputs from your repository in the CORE Repository Dashboard! CORE Repository Dashboard!