Study of the effect of pH, salinity and DOC on fluorescence of synthetic mixtures of freshwater and marine salts

In order to provide support for the discussion of the fate of organic matter in estuaries, a laboratory simulation was performed by changing freshwater ionic strength, pH and organic matter content. The change in spectroscopic characteristics caused by variations in salinity, pH and organic matter concentration in the filtered samples was observed by UV-Vis and fluorescence spectroscopy. The increase in emission fluorescence intensity of dissolved organic matter (DOM) due to increasing salinity (in the range 0 to 5 g l−1) is affected by the pH of the samples. The emission fluorescence intensity at the three maxima observed in the fluorescence spectra, is linearly correlated with dissolved organic carbon (DOC) concentration at several salinity values in the same sample. The increase in organic matter concentration caused a shift in the emission peak wavelength at 410 nm for several salinity values.We concluded that it is necessary to take into account the influence of salinity and pH on emission fluorescence of dissolved organic matter if it is to be used as a tracer in estuarine or near shore areas

A Method to Tackle First Order Differential Equations with Liouvillian Functions in the Solution - II

We present a semi-decision procedure to tackle first order differential equations, with Liouvillian functions in the solution (LFOODEs). As in the case of the Prelle-Singer procedure, this method is based on the knowledge of the integrating factor structure.Comment: 11 pages, late

Solving 1ODEs with functions

Here we present a new approach to deal with first order ordinary differential equations (1ODEs), presenting functions. This method is an alternative to the one we have presented in [1]. In [2], we have establish the theoretical background to deal, in the extended Prelle-Singer approach context, with systems of 1ODEs. In this present paper, we will apply these results in order to produce a method that is more efficient in a great number of cases. Directly, the solving of 1ODEs is applicable to any problem presenting parameters to which the rate of change is related to the parameter itself. Apart from that, the solving of 1ODEs can be a part of larger mathematical processes vital to dealing with many problems.Comment: 31 page

Comprehensive multidimensional liquid chromatography for advancing environmental and natural products research

Chromatography is the separation method of choice in most laboratories worldwide. Nonetheless, the increasing need to decode complex samples has created a demand for better separation skills. The addition of extra separation dimensions to a conventional liquid chromatography system was one of the ways to answer to this demand. Although very common in proteomics and polymer research, the use of Multidimensional Liquid Chromatography (MDLC) coupled to high-resolution detectors for separation and analysis of environmental and natural products samples has yet to receive the deserved attention. This article presents a critical review on the most prominent of these comprehensive MDLC methods for targeted and untargeted analysis of complex environmental and natural products samples. This article also discusses the practical aspects of applying peak capacity and orthogonality concepts in MDLC analysis of complex matrices. It also addresses the limitations and challenges ahead for advancing environmental and natural products research using comprehensive MDLC.Thanks are due to FCT/MCTES for the financial support to CESAM (UID/AMB/50017/2019) and project AMBIEnCE (PTDC/CTA-AMB/28582/2017), through national funds (OE). FCT/MEC and the European Social Fund are also acknowledged for a PhD grant (PD/BD/142931/2018) and an Investigator FCT Contract (IF/00798/2015).publishe

Biophysical probing of Spartina maritima photo-system II changes during prolonged tidal submersion periods

Submergence is one of the major constrains affecting wetland plants, with inevitable impacts on their physiology and productivity. Global warming as a driving force of sea level rise, tend to increase the submersion periods duration. Photosynthesis biophysical probing arise as an important tool to understand the energetics underlying plant feedback to these constrains. As in previous studies with Spartina maritima, there was no inhibition of photosynthetic activity in submerged individuals. Comparing both donor and acceptor sides of the PSII, the first was more severely affected during submersion, driven by the inactivation of the OEC with consequent impairment of the ETC. Although this apparent damage in the PSII donor side, the electron transport per active reaction centre was not substantially affected, indicating that this reduction in the electron flow is accompanied by a proportional increase in the number of active reaction centres. These conditions lead to the accumulation of excessive reducing power, source of damaging ROS, counteracted by efficient energy dissipation processes and anti-oxidant enzymatic defences. This way, S. maritima appears as a well-adapted species with an evident photochemical plasticity towards submersion, allowing it to maintain its photosynthetic activity even during prolonged submersion periods.The authors would like to thank to the “ Fundação para a Ciência e Tecnologia (FCT)” for funding the research in the Centre of Oceanography (CO) throughout the project PEst-OE/MAR/UI0199/ 2011, the Institute of Marine Research (IMAR) throughout the project PEst-C/MAR/UI0284/2011 and this specific work throughout the ECOSAM project (PTDC/AAC-CLI/104085/2008). B. Duarte investigationwas supported by FCT throughout a PhD grant (SFRH/BD/75951/2011)

Improving the Knowledge on Seismogenic Sources in the Lower Tagus Valley for Seismic Hazard Purposes

The Lower Tagus Valley, that includes the metropolitan area of Lisbon, has been struck by several earthquakes which produced significant material damage and loss of lives. Their exact location remains unknown. Our goal is to shed some light into the seismogenic sources in the area using seismic reflection and geological data. In areas with no seismic coverage, potential-field data interpretation was carried out. Seismicity was overlaid to the potential seismogenic structures and high-resolution data was acquired in order to confirm which structures have been active into the Quaternary. Three major fault-zones affecting the Neogene were identified: V. F. Xira, Samora-Alcochete and Pinhal Novo. For the first fault, strong evidences suggest it is active. The other two fault-zones and other structures previously unknown can be correlated with several epicentres. Empirical relationships between maximum moment magnitude and fault area indicate that MW > 6.5 earthquakes can be expected for the larger structures

Models of inflammation: Carrageenan- or complete Freund's Adjuvant (CFA)-induced edema and hypersensitivity in the rat

Animal models of inflammation are used to assess the production of inflammatory mediators at sites of inflammation, the anti-inflammatory properties of agents such as nonsteroidal anti-inflammatory drugs (NSAIDs), and the efficacy of putative analgesic compounds in reversing cutaneous hypersensitivity. This unit details methods to elicit and measure carrageenan- and complete Freund's adjuvant (CFA)-induced cutaneous inflammation. Due to possible differences between the dorsal root sensory system and the trigeminal sensory system, injections of either the footpad or vibrissal pad are described. In this manner, cutaneous inflammation can be assessed in tissue innervated by the lumbar dorsal root ganglion neurons (footpad) and by the trigeminal ganglion neurons (vibrissal pad)

Litostratigrafia do Jurássico Inferior da região de S. Pedro de Moel (Bacia Lusitânica, Portugal)

O Jurássico da região de S. Pedro de Moel constitui uma importante referência no estudo da Bacia Lusitânica. Neste trabalho apresenta-se uma caracterização litostratigráfica das unidades carbonatadas do Jurássico Inferior aflorantes neste sector da bacia, apoiada num novo esboço cartográfico. Em S. Pedro de Moel definem-se as Formações de Coimbra, Água de Madeiros, Vale das Fontes, Lemede e S. Gião, totalizando o intervalo compreendido entre o Sinemuriano Inferior e o Toarciano Médio. As três primeiras unidades mostram um registo estratigráfico muito completo, enquanto as duas mais recentes afloram de forma limitada, em consequência da intensa fracturação existente na região. [ABSTRACT]: The Jurassic in S. Pedro de Moel area is an important reference for the study of the Lusitanian Basin. In this work a lithostratigraphic characterization of the Lower Jurassic carbonate units that crop out in this sector of the basin is presented. This is supported by a new cartographic framework. In S. Pedro de Moel, the Coimbra, Água de Madeiros, Vale das Fontes, Lemede and S. Gião Formations are defined, comprising the Lower Sinemurian to Middle Toarcian interval. Whereas the first three formations show a very complete stratigraphical record, the latter two units are very poorly exposed, as a consequence of the intense tectonic activity in this area

Models of Inflammation: Carrageenan Air Pouch

The subcutaneous air pouch is an in vivo model that can be used to study the components of acute and chronic inflammation, the resolution of the inflammatory response, the oxidative stress response, and potential therapeutic targets for treating inflammation. Injection of irritants into an air pouch in rats or mice induces an inflammatory response that can be quantified by the volume of exudate produced, the infiltration of cells, and the release of inflammatory mediators. The model presented in this unit has been extensively used to identify potential anti-inflammatory drugs